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Pistonprop
10th Jul 2018, 16:40
ZS-BRV was due to be ferried from South Africa to the Aviodome in The Netherlands this month.It had been repainted in the old Martins Air Charter livery. News is coming in that it has crashed (on landing?) at Pretoria today. It broke into 3 parts and there are reports of 21 injuries.

Pistonprop
10th Jul 2018, 16:43
https://www.timeslive.co.za/news/south-africa/2018-07-10-20-injured-in-plane-crash-outside-pretoria/

Airbubba
10th Jul 2018, 17:12
I found a picture of ZS-BRV taken a couple of days ago with this note:

Photo DateJul 08, 2018UploadedJul 10, 2018NotesRecently repainted in the classic Martinair scheme of the 1960s in anticipation of its imminent departure to its new home at the Aviodrome Lelystad in the Netherlands. Departure is scheduled for 12 July and it should be arriving in the Netherlands on 23 July. I am sad to think that this is probably my final time photographing this beautiful aeroplane in South Africa but I at least know it is going to a good home.

https://www.jetphotos.com/photo/9002145 (https://www.jetphotos.com/photo/9002145)

Was the Martin's Air Charter lettering added (or revealed?) in the past couple of days?

Pistonprop
10th Jul 2018, 17:13
I believe the titles were added very recently.

Pistonprop
10th Jul 2018, 17:16
How does one modify the thread title? I think Pretoria, South Africa needs to be added. Mods, can you help?





Done.

Senior Pilot

Pistonprop
10th Jul 2018, 17:22
Aviodome reports it as a test flight. Is it customary to carry 19 pax on a test flight? Of course they may have all been personnel so to speak.

Hotel Tango
10th Jul 2018, 17:58
Minor typo: Convair 240 not 340.

Of origin yes. However, it was reported in several publications as having been converted to an CV-340. I have also seen it referred to as a CV-440, which it is not. Confusion may arise from the fact that the previous owner had 2 Convairs with that registration at one time or another.

GordonR_Cape
10th Jul 2018, 18:07
Casualties reported: https://www.news24.com/SouthAfrica/News/breaking-at-least-20-injured-in-wonderboom-plane-crash-reports-20180710

GordonR_Cape
10th Jul 2018, 18:43
Video of the takeoff seems to show engine smoke: https://www.youtube.com/watch?v=nitnw__7Qqg

rog747
10th Jul 2018, 19:40
yes it seems it blew the left engine just before or at rotation on the video - such a shame - one of the crew died RIP very sad
gorgeous old aeroplane - now in bits and gone forever
donated from Rovos Rail - sadly they had a very bad train crash a while ago with their vintage restored train which killed several crew

it seems the a/c was trying to get back to the airport PDQ and didn't make it crashing into a field after clipping a warehouse

anxiao
10th Jul 2018, 21:44
rog747 you do not know that a pilot died. You may have read that a crew member died. Please be careful with your terminology, there are next of kin out here trying to find the answers.

Hotel Tango
10th Jul 2018, 21:50
To be fair anxiao, several news sources are now quoting that one of the pilot's died.

anxiao
10th Jul 2018, 22:32
Which just shows how careful you have to be when re-quoting other sources. I shall not divulge my information here but even the EMS spokesperson did to know who had died.

To the press, anyone forward of the flight deck door is a pilot. If you know aviation, that is not a correct assumption.

Just stop being ghoulish until the next of kin have been informed.

Hotel Tango
10th Jul 2018, 22:43
Just stop being ghoulish until the next of kin have been informed.

Keep your hair on! I see no indication that anyone was being "ghoulish" here!

The Ancient Geek
11th Jul 2018, 01:43
The SACAA can be relied upon to publish a full investigation is due course, their work is always to a very high standard.
How good would the single engine performance be under hot & high conditions ?
The Convair would have a captain and a FO up front so "pilot" is ambiguous, would they also have a FE ?

aterpster
11th Jul 2018, 02:00
The SACAA can be relied upon to publish a full investigation is due course, their work is always to a very high standard.
How good would the single engine performance be under hot & high conditions ?
The Convair would have a captain and a FO up front so "pilot" is ambiguous, would they also have a FE ?
I believe the airplane was certified with a two-man (person) crew. As to single-engine performance just after lift-off, it was problematic. There was no requirement to meet a OEI takeoff flight path when these airplanes were certified. Could the failed engine prop be feathered? I don't have a clue.

Feather #3
11th Jul 2018, 03:29
The two pilots are personal friends of mine. Both are in a critical condition in J'burg hospitals.

They were taking the aircraft to the Aviodome tomorrow, expecting to complete the delivery within a week. The two SA engineers were accompanying them as they did for the delivery of the first aircraft to Australia.

It was to be a quick "run around the block" with the passengers those who had worked on and with the aircraft during their return to service following Rovos' choice to gift them to museums.

Let's keep those injured in our thoughts as many are quite ill and condolences to the deceased.

The facts will some later.

Gigajoules
11th Jul 2018, 04:55
https://cimg2.ibsrv.net/gimg/www.gmforum.com-vbulletin/800x593/cv240_crash_fawb_07_2018b_c9cf8bae9d170139c4a7357f9436ece578 abeb08.jpg

From a South African aviation site. Taken shortly after takeoff.

megan
11th Jul 2018, 06:11
it was reported in several publications as having been converted to an CV-340. I have also seen it referred to as a CV-440 The aircraft began life as a Convair C-131D-CO Samaritan, which was the military version of a 340. Registered in South Africa as a 340.

rog747
11th Jul 2018, 07:39
yes it seems it blew the left engine just before or at rotation on the video - such a shame - one of the crew died RIP very sad
gorgeous old aeroplane - now in bits and gone forever
donated from Rovos Rail - sadly they had a very bad train crash a while ago with their vintage restored train which killed several crew

it seems the a/c was trying to get back to the airport PDQ and didn't make it crashing into a field after clipping a warehouse

edited fatality seems I gather from later news and AVh it was reportedly the engineer (one of 2 on the flight?) who sadly succumbed to injuries RIP

seems the a/c went straight through the warehouse (not clipping it) :(

such a sad occurrence that a vintage airliner honoured for a historic Dutch charter airline ends of like this - condolences to all

Hotel Tango
11th Jul 2018, 10:42
The aircraft began life as a Convair C-131D-CO Samaritan, which was the military version of a 340. Registered in South Africa as a 340.

Correct, and as clearly stipulated by the OP in the thread title.

Dan_Brown
11th Jul 2018, 12:12
Sad news indeed.

The problem with that type of a/c is, loose an engine on T/O or near the ground as it seems in this case you're going down, period. If, and i mean if you get the prop feathered you will delay the inevitable. Remember you will have 5 minutes on the good engine, if you're lucky at max power. Also Wonderboom is 5500' approx, if memory serves me correctly.

Seems they were so unlucky. There but for the grace of God go I.

The Ancient Geek
11th Jul 2018, 13:16
Wonderboom has the additional problem of its location in a valley which acts as a heat trap, the temperature can get seriously high pushing the density altitude to nasty levels. Way back in the 70s I barely managed to get a C150 over the fence.
There are no reports of the conditions on the day but density altitude is a good candidate for a contributing factor.

aterpster
11th Jul 2018, 13:50
Wonderboom has the additional problem of its location in a valley which acts as a heat trap, the temperature can get seriously high pushing the density altitude to nasty levels. Way back in the 70s I barely managed to get a C150 over the fence.
There are no reports of the conditions on the day but density altitude is a good candidate for a contributing factor.
The left engine was trailing smoke.

Hotel Tango
11th Jul 2018, 14:02
The Dutch news has just reported a second fatality. This was a person inside the building which was struck by the aircraft.

JammedStab
11th Jul 2018, 15:38
Any autofeather on an aircraft like that?

Jhieminga
11th Jul 2018, 15:56
This article by John Deakin about the CAF's C-131 implies that the type does have an autofeather option: https://www.avweb.com/news/pelican/182145-1.html

PAXboy
11th Jul 2018, 16:38
It will be important to establish details of any other test flights since the refurbishment. Had the a/c performed normally in previous air-tests? Then no reason to deny a jolly to those who had done the work.

TIMA9X
11th Jul 2018, 17:01
more here as the story breaks in Australia,
Vintage plane crash: Qantas pilots fight for life (https://www.theaustralian.com.au/business/aviation/vintage-plane-crash-pilots-fight-for-life/news-story/7bb289aa91afcc3c3683f5b604a7db9f)

A second person has died as a result of a plane crash during a test flight in South Africa that left three Australians, including the two pilots, in hospital.Qantas said in a statement the airline’s pilot community was in “deep shock” after A380 captains Douglas Haywood and Ross Kelly, who is retired, were critically injured.The pair boast more than 37,000 hours’ flying experience between them and more than 30 years’ service with Qantas. Most on board were *pilots, flight engineers or aviation enthusiasts.“We were deeply upset to learn that two Qantas pilots, one current and one retired, were on board the vintage aircraft involved in an accident in South Africa on Tuesday,” a Qantas spokesman said last night.“This news has shocked the Qantas pilot community and everyone’s thoughts are with the families. We’ve reached out and are providing whatever support we can.”
https://cimg0.ibsrv.net/gimg/www.gmforum.com-vbulletin/760x911/0508_d8c91d833393105557155a22d9b9ec8c7bd8d51b.jpg

Gigajoules
11th Jul 2018, 17:47
Video of the takeoff: https://youtu.be/Zj2J-f7BsGc

wiedehopf
11th Jul 2018, 19:57
The SACAA can be relied upon to publish a full investigation is due course, their work is always to a very high standard.
How good would the single engine performance be under hot & high conditions ?
The Convair would have a captain and a FO up front so "pilot" is ambiguous, would they also have a FE ?

It's winter in South Africa so the temperatures are not that hot, but yes the airport is at 4100 ft elevation.
Can't find data for the past days but the current forecast for the next week does not go past 21C.

Still the aircraft type has only 44 passenger seats, so it was not exactly empty.

This article discusses the single engine shortcomings of the Convair 440, a development of the Convair 340.
http://aviationweek.com/bca/convair-s-failed-engine-out-return

tsgas
11th Jul 2018, 21:56
Turning back to the airport is not a realistic option in these circumstances. Our procedures called for a forced landings withing 45 degrees of our heading.

Zlinguy
11th Jul 2018, 22:21
The CV-440 was my first "real" flying job nearly 30 years ago - 2 of the 3 we flew have subsequently crashed ( one departing SJU under similar circumstances - ours were based in the states). It was mostly "On-the-Job Training", fortunately the Captains I flew with were very experienced and doled out prodigious amounts of "tribal knowledge". I honestly don't remember that much about the plane (other than it was old and leaky - even back then), but, almost every Captain was loathe to arm the Autofeather switch. Apparently it was implicated in several accidents when a faulty BMEP sensor (kind of a torque gauge) would trigger an autofeather of a perfectly functioning engine/prop. I believe the AUTO RICH/AUTO LEAN settings could get you in trouble pretty quickly, as well...

One of the crash reports cites a pilot stating that it was unlikely to climb at over 500'/min single-engine - I remember that number being our 2-engine rate-of-climb (mostly due to cooling issues). It was a very stable platform ( and a very robust airframe - I can attest to that), but, incredibly busy for the non-flying pilot to keep temps in the ideal range for different phases of flight adjusting cowl flaps, oil cooler doors, not reducing power below 100 BMEP for descent, etc...

I still have some old flight manuals from the mid-50's when our planes were operated by Delta Airlines...

Piloto Maluco
12th Jul 2018, 00:19
The CV-440 was my first "real" flying job nearly 30 years ago - 2 of the 3 we flew have subsequently crashed ( one departing SJU under similar circumstances - ours were based in the states). It was mostly "On-the-Job Training", fortunately the Captains I flew with were very experienced and doled out prodigious amounts of "tribal knowledge". I honestly don't remember that much about the plane (other than it was old and leaky - even back then), but, almost every Captain was loathe to arm the Autofeather switch. Apparently it was implicated in several accidents when a faulty BMEP sensor (kind of a torque gauge) would trigger an autofeather of a perfectly functioning engine/prop. I believe the AUTO RICH/AUTO LEAN settings could get you in trouble pretty quickly, as well...

One of the crash reports cites a pilot stating that it was unlikely to climb at over 500'/min single-engine - I remember that number being our 2-engine rate-of-climb (mostly due to cooling issues). It was a very stable platform ( and a very robust airframe - I can attest to that), but, incredibly busy for the non-flying pilot to keep temps in the ideal range for different phases of flight adjusting cowl flaps, oil cooler doors, not reducing power below 100 BMEP for descent, etc...

I still have some old flight manuals from the mid-50's when our planes were operated by Delta Airlines...

Thank you for your words, tha'ts why I am on PPrune... to read statements like yours...

Dan_Brown
12th Jul 2018, 00:42
That the pilots were experienced, is of no doubt. What I would be interested to know is this. How much of that experience was relative to that type of a/c and recent?

mrdeux
12th Jul 2018, 01:35
That the pilots were experienced, is of no doubt. What I would be interested to know is this. How much of that experience was relative to that type of a/c and recent?

They were both very active flying members of HARS, so they were flying a number of similar aircraft, from Constellation to Catalina. And a Convair.

Offchocks
12th Jul 2018, 01:49
That the pilots were experienced, is of no doubt. What I would be interested to know is this. How much of that experience was relative to that type of a/c and recent?

Both have been heavily involved for a number of years with the Historical Aircraft Restoration Society (HARS) south of Sydney. Together, the aircraft they have flown are the DC3, Caribou, Convair 440, Lockheed Super Constellation, Lockheed Neptune, PBY Catalina plus others.
They have been Senior Check Pilots with Qantas and are well thought of both operationally and socially.
I'm sure that a lot of people in Qantas and further afield are concerned for all that have been involved in this terrible accident.

megan
12th Jul 2018, 02:17
Correct, and as clearly stipulated by the OP in the thread title Unfortunately your post # 7 left me in some doubt, particularly as you quote in part a post that has been deleted in its entirety. I cleared up any possible confusion by making a categorical statement that aligns with the OP.

Nunc
12th Jul 2018, 02:47
That the pilots were experienced, is of no doubt. What I would be interested to know is this. How much of that experience was relative to that type of a/c and recent?

Doug ferried the Hars Convair out from South Africa last year.

mrdeux
12th Jul 2018, 04:04
Does anyone know the actual location of the accident?

GordonR_Cape
12th Jul 2018, 04:17
Does anyone know the actual location of the accident?
Plenty of Google Earth images here: https://avherald.com/h?article=4bafa778

Volume
12th Jul 2018, 07:45
There is a 1950s Convair promotion film on YouTube which shows a single engine take-off with a 340 completely on the right engine, claiming this aircraft does not share the typical weakness of the piston twins of that aera.
Might be a San Diego sea level test flight, with a totally different performance requirement.

Hotel Tango
12th Jul 2018, 10:08
OK understood megan, but you also quoted only a part of my post and omitted the part which said that it was not a 440 for sure. The post which was deleted (presumably by the poster) stated it was a CV-240. It actually was but prior to conversion, probably when still on the production line. I said that I had even seen references to it as a CV-440 and added that it definitely wasn't (which you omitted when quoting me). OK? Sorted :)

LynxDriver
12th Jul 2018, 10:14
rog747 you do not know that a pilot died. You may have read that a crew member died. Please be careful with your terminology, there are next of kin out here trying to find the answers.

To be honest, I doubt looking on this forum would be high on their list of things to do.

MarkerInbound
12th Jul 2018, 12:29
I believe the airplane was certified with a two-man (person) crew. As to single-engine performance just after lift-off, it was problematic. There was no requirement to meet a OEI takeoff flight path when these airplanes were certified. Could the failed engine prop be feathered? I don't have a clue.

I worked for a company that operated 8 recip Convairs in the late 80s. We had all 3 models. While the aircraft may have been certified under CAR4, we operated under FAR 121 and all the normal performance data was available. While Zlinguy's operation didn't use it, we checked the autofeather every runup and used it whenever required by the performance graphs.

aterpster
12th Jul 2018, 15:13
I worked for a company that operated 8 recip Convairs in the late 80s. We had all 3 models. While the aircraft may have been certified under CAR4, we operated under FAR 121 and all the normal performance data was available. While Zlinguy's operation didn't use it, we checked the autofeather every runup and used it whenever required by the performance graphs.
You were able to comply with 121.189?

Trossie
12th Jul 2018, 15:28
That crash site (as shown from GordonR_Cape's post) is a long way outside a right-hand circuit for the westerly runway! Handling must have been very difficult. There has been mention of 21degC and 4,100 ft elevation. With limited performance (on an aeroplane from an era when performance was not the same as expected now), the combination of 21C and 4,100 ft would be very significant.

Centaurus
12th Jul 2018, 16:02
Doug ferried the Hars Convair out from South Africa last year.https://www.pprune.org/images/statusicon/user_offline.gif https://www.pprune.org/images/buttons/report.gif (https://www.pprune.org/report.php?p=10194676) 000

I saw a media photo last year of that HARS Convair taken during its initial take off climb. As a former Convair 440 pilot from over 50 years ago, I noticed that one upper cowl flap was fully open on one engine. The angle of the photo restricted the view of both upper cowl flaps. Normally that would be a serious event as the drag from a fully open upper cowl flap would be prohibitive in event of an engine failure at that stage.
My thought was maybe the cowl flap motor was inoperative and the crew had perhaps mechanically wound the cowl flap to the full open position for a ferry flight due lack of spares at the point of departure. That would be inconceivable to me as the CHT on that engine would be very low with all that cooling airflow through the engine and effect on the cylinders. I wrote to HARS for their comment but received no acknowledgement

EastMids
12th Jul 2018, 18:00
Comments elsewhere corroborate what I already understood - Convair 340 ZS-BRV has done little flying in the last nine years (since 2009), with its very infrequent trips aloft comprising mainly moves from Lanseria to Wonderboom to Freeway and back to Wonderboom again for ongoing storage. I'm by no means suggesting the accident flight was the aircraft's first in recent days nor am I casting aspersions on the quality of the maintenance it had been subjected to ahead of the proposed ferry flight to the Netherlands, but the reality is that old piston engines such as the R2800 sometimes 'let go' unpredictably when they have been largely dormant and not run at demanding power settings on a regular basis for long periods. It may be of course that the powerplants were not a factor (albeit that video evidences points to engine problems) or they were changed ahead of its ferry to the Netherlands, in which case this post is meaningless.

GordonR_Cape
12th Jul 2018, 19:02
That crash site (as shown from GordonR_Cape's post) is a long way outside a right-hand circuit for the westerly runway! Handling must have been very difficult. There has been mention of 21degC and 4,100 ft elevation. With limited performance (on an aeroplane from an era when performance was not the same as expected now), the combination of 21C and 4,100 ft would be very significant.
Comments in the discussion on that link point out something crucial: The tracks into both the Wonderboom runways pass over densely populated suburban areas, whereas the crash location is a relatively sparsely built up patch. The suggestion is that the pilots tried to return, but the eventual loss of power forced them to ditch away from the airport.

The left engine did not fail instantaneously, as both propellers can be seen rotating in the takeoff video. What happened to the engine performance after that point should become clear during the inquiry.

Street garbage
13th Jul 2018, 00:09
One of the pilots involved in the accident had an engine failure in VH-TAA (VC-131D, ex ZS-ARV of Rovos Rail) whilst flying in Australia about a year ago. He was aware of the limitations of the single engine performance of the aircraft.

Centaurus
13th Jul 2018, 01:26
The left engine did not fail instantaneously, as both propellers can be seen rotating in the takeoff video

The propeller may have been windmilling creating huge drag and an observer would probably not know the difference..

B2N2
13th Jul 2018, 04:13
The propeller may have been windmilling creating huge drag and an observer would probably not know the difference..

To me it appears that the LH engine is still running as it crosses the fence.
There appears to be no banking to the live engine or any directional control issues as it crosses the fence.
what you do hear is an irregular Ďpoppingí sound.
With a radial engine ( or any reciprocating engine) you can have a partial engine failure ( loose a jug) follows by more cylinders failing.
So it drops 1-2-3- Cylinders in a short period of time.

megan
13th Jul 2018, 07:17
you also quoted only a part of my post and omitted the part which said that it was not a 440 for sure. The post which was deleted (presumably by the poster) stated it was a CV-240. It actually was but prior to conversion, probably when still on the production line. I said that I had even seen references to it as a CV-440 and added that it definitely wasn't The aircraft in question was never a 240. 131D models were based on a mix of 340 and 440 airframes, some of the 131's were converted civil airframes and some new builds. ZS-BRV was a new build 131D airframe and civilianized as a 340-79 in accordance with its TCDS.

Re certification, TCDS,Type Certificate No. 6A6 (Transport Category, CAR 4b, effective July 20, 1950, and Amendment #1, #3, and #5, except smoke detectors not installed in cargo compartments

Re auto-feather, TCDS,Ferry permits may be issued to all Model 340 aircraft on which the automatic propeller feathering system is inoperative. Continuous operation with the automatic propeller feathering system inoperative can be accomplished on some Models in accordance with Appendix "C" of the FAA Approved Airplane Flight Manual. Operating procedures, power ratings and performance data contained in Appendix "C" of the Approved Airplane Flight Manual applicable to the CB3/CB16 engines may be used for the CB4/CB17 engines.Drag from the cowl flaps must be significant, did see a report years ago when a crew found themselves in the same predicament as this, feathered prop and fully closed the cowl flaps on the operating engine in an endevour to gain performance for a quick circuit while placing their faith in Mr. P & W to withstand the abuse. They made it.

dhavillandpilot
13th Jul 2018, 07:43
My dad use to fly the CV 240's for Butlers/Airlines of NSW.

Before that the Airspeed Ambassador.

He always said the Convair would kill him whilst the Ambassador would get him home.

He breathed a sigh of relief when the Covairs were sent to Airlines of SA and Air NSW got the Fokkers

Centaurus
13th Jul 2018, 08:17
Drag from the cowl flaps must be significant, did see a report years ago when a crew found themselves in the same predicament as this, feathered prop and fully closed the cowl flaps on the operating engine in an endevour to gain performance for a quick circuit while placing their faith in Mr. P & W to withstand the abuse. They made it
From recollection the cowl flaps were selected to the trail position (or takeoff/climb position, whatever it was called then) immediately before commencing the take off roll. The drag would be minimal. The difference between trail (or climb position) and closed was also minimal. Certainly in my time you would never take off with cowl flaps wide open and it certainly was never in the Ops manual for the type..
On one occasion at an Australian outback airport with no servicing facilities, we discovered the left engine upper cowl flap failed in the full open position while we were taxiing in after landing.
After discussion with our flight engineer, he suggested he mechanically wind the cowl flap down to the trail or take off position and lock it in place. We then taxied out on one engine until lined up for take off. We then started that engine and when the engine oil temp was within the lower limit for take off we departed and CHT remained normal for the remainder of the three hour flight. After landing we closed down that engine to prevent increase in CHT and taxied in on one engine.

flyboyike
13th Jul 2018, 16:03
I remember at least a decade back there was a C-131 for sale on ebay still in full US Navy regalia. It looked more or less complete, but was not airworthy. The seller made sure to mention that the aircraft had been inspected by Kelowna Flightcraft (who, as I understand it, own the type certificate) and found to be "restorable to Part 121 standard". However, naturally, the cost of such a restoration was not mentioned. I haven't seen the aircraft since, so I assume it's sitting derelict somewhere.

Sure is a shame about the crash, I believe that was the last airworthy C-131 in the world.

Sheikh Your Bootie
14th Jul 2018, 00:16
Nope, HARS have one in Australia and Conquest Air fly 3 or 4 out of Opa Locka

Convair

SyB.

RobertS975
14th Jul 2018, 01:56
The Conquest craft looks like it has been converted to a CV-580?

Airbubba
14th Jul 2018, 02:10
The Conquest craft looks like it has been converted to a CV-580?

If it has, it's missing a prop blade on each side.

Hotel Tango
14th Jul 2018, 11:33
The Conquest craft looks like it has been converted to a CV-580?

Better inform the FAA quick, they have it as an C-131F ;)

A Squared
14th Jul 2018, 18:39
However, it was reported in several publications as having been converted to an CV-340.

Is that even possible? I'm not a Convair expert but I seem to recall that a 340 had a longer wing than the 240.

A Squared
14th Jul 2018, 19:10
Better inform the FAA quick, they have it as an C-131F ;)

The plane in the photo is obviously a piston Convair, but looking in the FAA aircraft registration database doesn't necessarily tell you whether a plane is a 580, a 580 will still be registered as a CV340, or CV440. For aircraft certification purposes, a 580 isn't an aircraft type, it's an STC modification.

A Squared
14th Jul 2018, 19:48
As to single-engine performance just after lift-off, it was problematic. There was no requirement to meet a OEI takeoff flight path when these airplanes were certified.

The 240 was certified under CAR 4b, effective 1946. that version of the CAR contained a requirement for OEI performance CAR 4b.116.

MarkerInbound
15th Jul 2018, 22:00
You were able to comply with 121.189?

We operated piston Convairs under part 121, we had to meet 121.177.

GordonR_Cape
15th Jul 2018, 22:21
Link posted on the internet of a remarkable video from a light aircraft showing the last minutes of this flight. Image quality is limited, but confirms that it was struggling to hold altitude before crashing: https://www.youtube.com/watch?v=uU9grBWybQ0

Trossie
15th Jul 2018, 22:47
From what someone has posted here, the density altitude would have been about 5,700 ft. That would not be good for performance on a limited performance aeroplane. That was a long way that they struggled with it.

4 Holer
15th Jul 2018, 22:48
Very sad indeed. FYI United States FAA SFP ( Ferry Permit ) for aircraft that size not on FAA121 AOC/Ops specs. Essential crew only ( 3 max ) plus mechanic all must hold FAA license, this old machine seems was a straight out ferry candidate only. Read she was carrying 19 pax and gear maybe 2000kg I guess to much at her age at 5700 foot field elevation. I hope all are recovering quickly, looks like crew did the best with what they were given.

aterpster
16th Jul 2018, 01:18
We operated piston Convairs under part 121, we had to meet 121.177.Good catch! I am jet oriented.

Capt Fathom
16th Jul 2018, 01:34
Image quality is limited, but confirms that it was struggling to hold altitude before crashing

Not sure you can tell that from the video, but it certainly had plenty of speed. Passed that C172/182 like it was standing still!

Perhaps that smoking engine was still producing power at that stage?

Dan_Brown
16th Jul 2018, 07:10
Yes the crew certainly put up a good fight. The real reason all? got out alive, is they seemed to have hit the ground "under control", therefore not stalled. A lesson for us all. Unfortunatly the TAS/ground speed would have been high, considering the D.A.

The Ancient Geek
16th Jul 2018, 11:41
With both pilots alive they should be able to give a good account of what happened to the enquiry, they should be out of hospital soon. There may well be other contributing factors such as problems with the gear or flaps.

Capt Fathom
16th Jul 2018, 12:38
they should be out of hospital soon

If current media reports are true, both pilots are still in induced comas, and unlikely to be out of hospital any time soon.
When they do come around, Iíd be surprised if they remember anything that happened that day.

aterpster
16th Jul 2018, 13:36
The 240 was certified under CAR 4b, effective 1946. that version of the CAR contained a requirement for OEI performance CAR 4b.116.
Did that require a regulatory-defined takeoff flight path to clear all terrain and obstacles to a specified altitude?

MarkerInbound
16th Jul 2018, 15:21
No, CAR 4 and the current part 25 are only certification rules that set certain performance requirements. CAR 4 required rates of climb that were a function of stall speed. FAR 25 requires set climb gradients. At least in the USA part 121 requires the operator to work backwards from the manufacturer's performance data to insure obstacle clearance taking into consideration current conditions.

A Squared
16th Jul 2018, 16:04
Did that require a regulatory-defined takeoff flight path to clear all terrain and obstacles to a specified altitude?

CAR4b-116 defines the takeoff path segments and CAR4-b.120 specifies the OEI takeoff performance. Why is it so astonishing to you that an aircraft certificated in the transport category for airline operations post WWII ans operated by airlines has OEI takeoff performance?

A Squared
16th Jul 2018, 16:08
CAR 4 required rates of climb that were a function of stall speed. FAR 25 requires set climb gradients.

True, but a climb rate specified as a ratio of speed equates to a gradient, even though the gradient isn't stated explicitly.

aterpster
16th Jul 2018, 16:20
CAR4b-116 defines the takeoff path segments and CAR4-b.120 specifies the OEI takeoff performance. Why is it so astonishing to you that an aircraft certificated in the transport category for airline operations post WWII ans operated by airlines has OEI takeoff performance?
Not astonished at all. Just trying to learn something about the piston era.

A Squared
16th Jul 2018, 16:39
Not astonished at all. Just trying to learn something about the piston era.

OK, it seemed to me like you were resisting the notion, which seemed surprising coming from someone from the era when seeing Convairs, DC-6's and the like flying for the airlines was pretty common.

aterpster
16th Jul 2018, 17:43
OK, it seemed to me like you were resisting the notion, which seemed surprising coming from someone from the era when seeing Convairs, DC-6's and the like flying for the airlines was pretty common.
When I went to work for TWA in early 1964, they were still flying the Connie. I just missed being a F/E on it. 3 years later I just missed it for my initial captain upgrade. So, I was not exposed to piston planning and performance. TWA had retired the Martin before I came aboard, which would be the closet to the Convair twins.

Before I learned to fly I rode on UAL's DC-6s several times. I didn't have a clue about the airspace or airway structure at the time. I do recall riding from Stapleton to Burbank one Spring (1955) afternoon. There were peaks higher than us on both sides somewhere in the Rockies. The cu was building around us. Suddenly, we were solid IMC and the g-load increased until we popped out going eastbound. That was a learning experience.

IcePack
16th Jul 2018, 17:58
Did a little time on Curtiss C46. Engine failure if you could start chucking the freight if you couldn’t pick a field. But they we’re controllable & great fun to fly. Different times different rules. To be honest that experience stood me in very good stead with the big jets. Imho the pilots in this incident were some of the best so there for the grace of God.
Hope they recover.

EDML
16th Jul 2018, 18:00
With both pilots alive they should be able to give a good account of what happened to the enquiry, they should be out of hospital soon. There may well be other contributing factors such as problems with the gear or flaps.

They got the gear up very early while still being over the runway. That shows that they where aware of the situation pretty soon.

sycamore
16th Jul 2018, 20:36
Anyone know if #1 prop was feathered at any point,and, if the aircraft used water/water-meth. injection...?

Hotel Tango
16th Jul 2018, 21:41
They got the gear up very early while still being over the runway. That shows that they where aware of the situation pretty soon.

Hmm, could be, but my recollection of flying in the piston era was that the gear coming up early was fairly standard.

A Squared
16th Jul 2018, 21:41
They got the gear up very early while still being over the runway. That shows that they where aware of the situation pretty soon.

You'd select gear up as soon as you had a positive indication of climb. That's usually over the runway.

MarkerInbound
17th Jul 2018, 00:28
I remember the instructor for my initial Convair class saying that the gear retract speed was the fastest of any of its generation aircraft specifically to improve the engine out performance.

bront
17th Jul 2018, 02:33
Anyone know if #1 prop was feathered at any point,and, if the aircraft used water/water-meth. injection...?

On a South African forum it was reported that they had planned to use water/meth for this take off. Apparently this was infamous for causing backfiring leading to the auto feather engaging so many crew didn't arm the auto feather. The use of water/meth could well explain the popping we hear on take off. They also had a habit of exhaust system fires aft of the engine.

Looking at the vid from the Cessna I would guess that they had both engines running until they turned onto base considering the speed they were doing. Something happened on the base leg for them not to turn onto final. May be they shut down the engine and it wouldn't feather.

4 Holer
17th Jul 2018, 03:20
Most likely Cylinder head cracked then blew off thus constant smoke out one exhaust on that cylinder side. If it dropped a valve it will maintain power at 30 inches or barometric but will PUFF Smoke not stream smoke. If smoke trailing from both exhausts it is a blown supercharger drive seal or broken supercharger drive the later will have the engine stop and windmill, if it breaks the front reduction gearbox gear may end up with a run away prop.
With blown off cylinder head you can in emergency keep running the engine at higher power (or barometric if its banging to much with the blown cylinder ) which is what you maybe seeing going on from the Cessna video and the takeoff. It shakes like hell for few minutes but will put out until the piston comes apart, breaks the rod at which time you feather it . Sometimes will run 1 minute sometimes 2-3mins dependent where the cylinder head comes off. Had 8 failures myself with R1830-92 and R2800-CB16s. 1 Master rod, 1 rod, 2 dropped valves the others were cylinder head blew off some through the cowl. When these big radials stop suddenly from seizure other things break and shear it is a lot of mass and moving parts
All my failures on takeoff or first stage power reduction. All at sea level and that was bad enough. Just some technical thoughts but the investigators will advise later.

They did a good job with what they were given on the day, speedy recovery to all..

EDML
17th Jul 2018, 03:23
You'd select gear up as soon as you had a positive indication of climb. That's usually over the runway.

I do know that. However, seeing the very shallow climb I seriously doubt they had a positive indication on the VSI. They where desperate to reduce the drag ASAP.

A Squared
17th Jul 2018, 04:58
I do know that. However, seeing the very shallow climb I seriously doubt they had a positive indication on the VSI. They where desperate to reduce the drag ASAP.



So, how much experience do you have flying recip airliners from that era? I have quite a few thousand hours in them. Different airplane, same engine. I can tell you a couple of things, one is that on a hot day, in good VFR conditions it was absolutely normal to make a very shallow initial climb. The reason being that you wanted to build airspeed rapidly, to increase the cooling airflow over the cylinders, which will be hovering around redline very quickly, and also to more quickly reach the airspeed at which you make the first power reduction and also allows you to turn off the ADI, which causes the fuel air mixture to enriched. And yeah, you most certainly do get a positive rate indication on your instruments with a very shallow climb like that. Gear retraction at my airline was called as soon as the VSI was above zero and the altimeter was showing positive movement. That would be pretty much what you saw in the video. There's aren't turbine aircraft, they don't fly like turbine aircraft, you don't fly them like turbine aircraft, and they don't look like turbine aircraft when you're watching them.

cooperplace
17th Jul 2018, 08:32
Had 8 failures myself with R1830-92 and R2800-CB16s. 1 Master rod, 1 rod, 2 dropped valves the others were cylinder head blew off some through the cowl. When these big radials stop suddenly from seizure other things break and shear it is a lot of mass and moving parts
.amazing, 8 failures would give you grey hair, thank goodness for the jet age

Dan_Brown
17th Jul 2018, 09:32
I do know that. However, seeing the very shallow climb I seriously doubt they had a positive indication on the VSI. They where desperate to reduce the drag ASAP.



Sorry to be pedantic but at, or soon after rotate the VSI, depending on the type of aircraft may well give erroneous readings. As correctly pointed out above, a positive climb is reliably indicated by the altimeter.

Centaurus
17th Jul 2018, 12:13
Apparently this was infamous for causing backfiring leading to the auto feather engaging so many crew didn't arm the auto feather.

Sounds like an Old Wives Tale. Flying the Convair 440 I have used ADI on hundreds of occasions. Not once did I experience back-firing on take off. Certainly we experienced occasional rough running due to spark plug fouling with 115/145 Octane fuel but it usually cleared itself during initial climb. As far as I recall autofeather was armed for every take off. .

Old Fella
17th Jul 2018, 12:17
Sorry to be pedantic but at, or soon after rotate the VSI, depending on the type of aircraft may well give erroneous readings. As correctly pointed out above, a positive climb is reliably indicated by the altimeter.
I do not dispute the point regarding erroneous VSI indications, however the call often is "Positive Rate, Gear Up"

EDML
17th Jul 2018, 13:33
So, how much experience do you have flying recip airliners from that era? I have quite a few thousand hours in them. Different airplane, same engine. I can tell you a couple of things, one is that on a hot day, in good VFR conditions it was absolutely normal to make a very shallow initial climb. The reason being that you wanted to build airspeed rapidly, to increase the cooling airflow over the cylinders, which will be hovering around redline very quickly, and also to more quickly reach the airspeed at which you make the first power reduction and also allows you to turn off the ADI, which causes the fuel air mixture to enriched. And yeah, you most certainly do get a positive rate indication on your instruments with a very shallow climb like that. Gear retraction at my airline was called as soon as the VSI was above zero and the altimeter was showing positive movement. the would be pretty much what you saw in the video. There's aren't turbine aircraft, they don't fly like turbine aircraft, you don't fly them like turbine aircraft, and they don't look like turbine aircraft when you're watching them.

Only airplane with a radial engine I have ever flown was a T-6/Harvard (also in South Africa). Of course that is no airliner and it has plenty of power.

Anyways, from your experience would you rate the climb while over the runway (and of course still accelerating) as normal for these kind of aircraft? Of course the density altitude of at least 5,000ft (not sure about the OAT that day) plays a big role, too.

I am just interested if they still had power from the left engine at that point. There is no visible yaw and no bank towards the "good" engine but unfortunately you can't see the rudder on the video or any of the pictures after lift-off.

Does anybody know the blue line speed of a CV-340?

A Squared
17th Jul 2018, 15:14
Sounds like an Old Wives Tale. Flying the Convair 440 I have used ADI on hundreds of occasions. Not once did I experience back-firing on take off. Certainly we experienced occasional rough running due to spark plug fouling with 115/145 Octane fuel but it usually cleared itself during initial climb. As far as I recall autofeather was armed for every take off. .

I had never heard of ADI causing backfiring either, at least not a properly functioning system. I did have one incident where I rejected a takeoff due to backfiring and it turned out to be a ruptured diaphragm in the ADI regulator. However that problem made itself evident as soon as the throttles were pushed up far enough for the ADI flow to start. WE didn't arm auto feather, but it was only required for takeoffs over 100,000 lb, and our operations were relatively short legs so were were always landing weight limited, so never needed to depart over 100,000lb.

A Squared
17th Jul 2018, 15:29
I do not dispute the point regarding erroneous VSI indications, however the call often is "Positive Rate, Gear Up"

Meaningless semantics. A Positive Climb is inherently also a positive rate of climb. The SOP call at my current airline is "Positive Climb"

RatherBeFlying
17th Jul 2018, 15:42
Post WWII most piston airliners were certified on 115/145.

On 100LL derates have to be applied. Engine out performance on 100LL will be less than on 115/145.

pineteam
17th Jul 2018, 15:44
Meaningless semantics. A Positive Climb is inherently also a positive rate of climb. The SOP call at my current airline is "Positive Climb"

Same as in my company: I believe it's an Airbus standard call out. Also in our SOP, the '' Positive Climb'' call out is based on RA, not on VSI or altimeter as both will increase while the main gear are still on the ground.

A Squared
17th Jul 2018, 15:45
Anyways, from your experience would you rate the climb while over the runway (and of course still accelerating) as normal for these kind of aircraft? Of course the density altitude of at least 5,000ft (not sure about the OAT that day) plays a big role, too.

My time radial engined airplanes was all in far northern climates at close to sea level. Given that this was, as you say, a much higher elevation and possibly warmer OAT I wouldn't consider the low initial climb extraordinary.

I am just interested if they still had power from the left engine at that point. There is no visible yaw and no bank towards the "good" engine but unfortunately you can't see the rudder on the video or any of the pictures after lift-off.

As someone else noted earlier, it is quite possible for an engine to have a cylinder failure and still be producing a substantial amount of power.

Does anybody know the blue line speed of a CV-340?

I haven't flown the Convairs, but I'd expect that it didn't have a blue line, but rather V speeds which were calculated based on takeoff weight, altitude and OAT. Blue-line is more light twin figure. It's possible though, that era was kind of a transitional period for aircraft performance theory.

EDML
17th Jul 2018, 16:04
I haven't flown the Convairs, but I'd expect that it didn't have a blue line, but rather V speeds which were calculated based on takeoff weight, altitude and OAT. Blue-line is more light twin figure. It's possible though, that era was kind of a transitional period for aircraft performance theory.

So it would rather be V2 then, like with a jet. Anyways, the numbers would be interesting. They seem pretty fast passing the 172 in the 2nd video.

A Squared
17th Jul 2018, 16:07
Post WWII most piston airliners were certified on 115/145.

On 100LL derates have to be applied. Engine out performance on 100LL will be less than on 115/145.

Not exactly true. The R2800 CB16 engine was certified on 100/130 for which 100LL is an approved alternate with no reduction in power. the CB17 was certified on 115/145 and would develop an additional 100 HP The Convair 340 may have had several different model engines installed, including the CB16 and CB17

EDML
17th Jul 2018, 16:09
As someone else noted earlier, it is quite possible for an engine to have a cylinder failure and still be producing a substantial amount of power.

That was, what I was thinking of. There is no yaw visible at all. Even if you react very quickly I would expect at least a little yaw at low speed and high power.

PJ2
17th Jul 2018, 18:24
There is no yaw visible at all. Even if you react very quickly I would expect at least a little yaw at low speed and high power.

Yes, power had to have been developed at least right after takeoff as the rudder is faired in the video as the aircraft passes overhead and away from the camera.

EDML
17th Jul 2018, 21:12
Yes, power had to have been developed at least right after takeoff as the rudder is faired in the video as the aircraft passes overhead and away from the camera.

Correct. In the video that shows the T/O from behind the runway you can see that there is no rudder used after the A/C overflew the camera. Power seems to be evenly distributed.

Hotel Tango
18th Jul 2018, 00:28
There is now a video circulating taken from inside the aircraft, left side, with the rear of the engine in view. The video continues to and beyond impact.

777fly
18th Jul 2018, 00:31
The gear was obviously retracted very early and there is no rudder input or yaw. Perhaps a premature retraction caused the props to hit the ground, with consequential damage and power loss on BOTH engines?

Hotel Tango
18th Jul 2018, 00:32
Taken from inside.

https://www.youtube.com/watch?v=YlWXhGlvLp0

EDML
18th Jul 2018, 00:42
Looks like the left engine finally failed while they where about to turn base or final (hard to tell as they are making a constant shallow turn.) Maybe that was all they could get turning over the running engine.

The left aileron looks strange. It seems to be deflected upwards a lot which neither makes sense in a right turn nor with a failing left engine. That might also be due to the quality of the video, though.

Mach E Avelli
18th Jul 2018, 01:04
While not wishing to speculate or pre-empt the investigation into this tragedy, the following personal experience of what can happen when an aircraft has been out of service for a protracted period may be worth relating.
In early 1993, I was contracted to ferry a Vickers Viscount from the USA to Zaire, This was an early 700 series that had been a VIP machine for some of its life, so had relatively low hours. It had been on a storage maintenance program in the Arizona desert. They had kept enough fuel in the tanks to carry out periodic engine runs. When we took delivery and did a short test flight I was pleasantly surprised at how all the systems except the autopilot seemed good to go.
We refuelled to full tanks to position from Tucson to Mena, where we would fit extra ferry tanks. About two hours into the flight the number one engine ran down and autofeathered, quickly followed by number two surging badly. A quick right hand turn and down we went towards Ardmore, noting all remaining fuel flowmeters were fluctuating.
At shutdown it was found all four fuel filters were badly clogged with rubber deposits.
Having been baking in the desert for so many years, the tops of the fuel bladders had badly perished. It was OK while a small amount of fuel remained in the tanks as it kept the lower sections moist enough not to leak. But once we went to full tanks the fuel sloshing around washed the rotten rubber into the system.
Could it be that this model Convair has rubber tanks, or rubber fuel lines? An engine running at high power suddenly leaned out due to fuel blockage would possibly backfire badly. This could cause a supercharger fire with no immediate loss of power, so no noticeable rudder input. Or a dramatic loss of power on both engines could explain the rudder position. Another possibility is a rotten or burst fuel line could have caused the fire, and the fire could have damaged the aileron circuit.

MarkerInbound
18th Jul 2018, 01:41
The CB-3 and CB-16 were certified on 100/130, the CB-4 and CB 17 were certified on 108/135 brown gas.

megle2
18th Jul 2018, 07:08
After following all the posts, seeing the extent of physical airframe damage and then watching that on board video which continues recording well after impact I was amazed at how well the passengers seemed to handle it.

dak095
18th Jul 2018, 08:40
In looking at the internal footage a few notable observations are apparent

1, sooting on the panel junction in front of the exhaust outlet, and 2 fire under the wing - which is definitely abnormal and extremely alarming.

It would be a presumption that a fire has broken out, at some stage, either between the engine power section firewall and nacelle firewall, or a mechanical failure has occurred with the engine power section(Cylinder or multiples of, or rotating elements) and an uncontrolled oil leak is igniting on the exhaust and exiting vial the cowl flaps - which there would be no fire suppressant for(reserved for the Accessories section - oil and Fuel services etc).

In the departure video there is clear flaming in the exit area of the augmenter, which indicated something mechanical is amiss in there, the popping of the engine, smoke and strobe effect of the video indicates RPM changes occurring, and waiting for the Governer to assert itself - rpm recovery. Im going to assume the later - if you have a fire in the accessory section, fire alarms would sound, the engine(if determined is overheating/or on fire) would be secured and extinguishers used - Securing of would cut fuel and oil supplies and stop pumps for doing just that - The propwould also be feathered and stopping rotation.

A failure in the Power section may produce a fire that cant be seen, and if still producing power may lead you to continue until safe to secure. As for landing in a paddock - there are two pilots who will know the events relating to those decisions. Mine is but speculation, I am willing to speculate that they may have been made aware of an external fire late in to the flight and decided being on the ground in a controlled fashion was a better outcome. than pushing on to the runway.

Overtheditch
18th Jul 2018, 08:44
Ordinarily I would have thought that this crash was unsurvivable, looking at the pictures. I am inclined to agree with an earlier post that this craft was "crash landed" rather than "crashed", that is it was under control. Another reason for the high survival rate is the incredible strength of these old birds. I sure would not have liked to see a plastic fantastic composite aircraft after an arrival like this.

The pax, to the best of my knowledge were aviation people or the family of aviation people so much more likely to stay calm under the circumstances.

Dan_Brown
18th Jul 2018, 10:42
Looks like the left engine finally failed while they where about to turn base or final (hard to tell as they are making a constant shallow turn.) Maybe that was all they could get turning over the running engine.

The left aileron looks strange. It seems to be deflected upwards a lot which neither makes sense in a right turn nor with a failing left engine. That might also be due to the quality of the video, though.

I suspect the P.F. had a bootful of right rudder. Which would be consistent with power loss on the port engine. How much aileron needed to control the aircraft laterally, hence crossed controls is anyones guess. I also suspect the prop was not feathered for whatever reason, at or just before impact looking at the rotating prop in the clip.

Capt Fathom
18th Jul 2018, 11:51
What an awful video to watch.
Based on the pilots previous experience, I can only speculate they were not convinced the aircraft would fly on one engine.
They kept that crook engine running for as long as possible. I would probably have done the same. At least they flew that aircraft to the crash site.

Double Back
18th Jul 2018, 12:23
The upward aileron puzzles me, it was not in T/O or shortly after. It looks like it is jammed full upward. It could indicate they could not crank the plane in a right turn to join final. To me it looks like the nr1 continued delivering power. The last sec before impact You hear the engine(s) roaring up.
If the jammed aileron proves to be the scenario, they have met a miserable set of emergencies. For the sake of the investigation it would be nice that they could remember a few things but for the sake of their mind it would be good if all after T/O is erased. So they will not end up waking up now and then from a nightmarish dream the rest of their life.
I wish them a good recovery.

GA Driver
18th Jul 2018, 12:54
Theres a surge/power change at 43-44 seconds as well. It actually sounds like a reduction or miss then returns quickly thereafter.

Centaurus
18th Jul 2018, 14:33
The upward aileron could have been a momentary turn of the control wheel taken by entire coincidence at that split second the camera shutter operated. I guess the question is why the prop was not immediately feathered but allowed to run during the entire attempted circuit - particularly as a fire in that engine was noticeable to the passengers. No doubt there will be a logical explanation to be revealed during the formal investigation.

Dogma
18th Jul 2018, 17:16
Very impressive Passengers, perhaps engineers, no simpering or calling for Mama. Afrikaners :-)

Hate to suggest they may have shut the wrong engine down, brief I make when flying with an engineer.. donít shut anything down without explicit instructions. Thrash it if necessary, preservation off the menu

letís hope itís not the case

cappt
18th Jul 2018, 20:44
Agree, the almost full up left aileron, (left wing down) is really troubling. I remember 2-3 deg. bank towards the good engine and appropriate rudder is what we trained for on the turboprop I flew.

EDML
18th Jul 2018, 21:01
Agree, the almost full up left aileron, (left wing down) is really troubling. I remember 2-3 deg. bank towards the good engine and appropriate rudder is what we trained for on the turboprop I flew.

Correct. There might be some cross control with the rudder full right, but surely not full left aileron. With light GA piston twins even on a single engine go around there is only a bit of aileron needed.

Chris Scott
18th Jul 2018, 21:14
Yes, power had to have been developed at least right after takeoff as the rudder is faired in the video as the aircraft passes overhead and away from the camera.

Looking at that same video of the take-off, taken from the perimeter fence, I agree with you and EDML.

But there is some suggestion in the video that the RPMs of the two engines are already different. I don't know the R2800, but presume both props are selected to full-fine pitch for the take-off? So, like the R1830 (Twin Wasp) with which I used to be familiar, the RPM depends purely on the power available.

Videos, of course, are almost completely useless at representing props at running rpm. But not completely useless in this instance. Watching the video, the props appear at first to be rotating (albeit much slower than reality, but in the correct direction for a right-hand tractor) at the same speed. But, at elapsed times 8, 11 and 13 secs, the port prop seems to hesitate, whereas the starb'd does not. That is when the a/c is approaching the camera. We know from both videos, of course, that the port engine was on fire, whereas the starb'd seems okay. So I infer that the port prop was slower than the starb'd.

From about 15 secs, with the a/c going away from the camera, the port prop (as falsely represented by the video) starts to rotate much faster than the starb'd. IMO, that indicates that the prop had actually slowed down, but I wouldn't have any idea by how much. The other possibility, which seems highly unlikely, would be that the starb'd prop was being feathered and slowing down (i.e., the starb'd engine being shut down). No doubt, analysis based on the camera's frame-rate would enable someone to estimate the relative RPMs, but they are definitely asymmetric.

DaveReidUK
18th Jul 2018, 21:32
No doubt, analysis based on the camera's frame-rate would enable someone to estimate the relative RPMs, but they are definitely asymmetric.

I'm not so sure about that. Determining PRPM from a video is a non-trivial exercise.

Chris Scott
18th Jul 2018, 22:26
I'm not so sure about that. Determining PRPM from a video is a non-trivial exercise.
Which is why I'm not going to attempt it, Dave... :cool:

EDML
18th Jul 2018, 22:27
Videos, of course, are almost completely useless at representing props at running rpm. But not completely useless in this instance. Watching the video, the props appear at first to be rotating (albeit much slower than reality, but in the correct direction for a right-hand tractor) at the same speed. But, at elapsed times 8, 11 and 13 secs, the port prop seems to hesitate, whereas the starb'd does not. That is when the a/c is approaching the camera. We know from both videos, of course, that the port engine was on fire, whereas the starb'd seems okay. So I infer that the port prop was slower than the starb'd.

From about 15 secs, with the a/c going away from the camera, the port prop (as falsely represented by the video) starts to rotate much faster than the starb'd. IMO, that indicates that the prop had actually slowed down, but I wouldn't have any idea by how much. The other possibility, which seems highly unlikely, would be that the starb'd prop was being feathered and slowing down (i.e., the starb'd engine being shut down). No doubt, analysis based on the camera's frame-rate would enable someone to estimate the relative RPMs, but they are definitely asymmetric.

The perceived rotation of the props on the video are interferences between the acutal propeller RPM and the video frame rate. When the frame rate is exactly in sync with a full, a 1/3rd or 2/3rd revolution of the prop the blades seem to stop. So far so good. We can assume that the RPM is the same when both props seem to stop.

Due to the interference a very small change of RPM (e.g. 20 RPM) will look totally different on the video. Therefore you cannot deduct anything meanigful from the perceived change in RPM in the video.

I watched a couple videos on YouTube showing Prop Airliner taking off (e.g. DC-6). The effect is exactly the same - direction and speed of the props seem to change through the T/O run.

point76
19th Jul 2018, 00:13
Other posts have pointed out the deflected aileron from the new vision looking out at the left wing. It does appear to be fully deflected up which means set for a left bank or the opposite to what would would be expected with a left engine failure. Maybe a clue to something worse going on ?

Chris Scott
19th Jul 2018, 00:46
The perceived rotation of the props on the video are interferences between the acutal propeller RPM and the video frame rate. When the frame rate is exactly in sync with a full, a 1/3rd or 2/3rd revolution of the prop the blades seem to stop. So far so good. We can assume that the RPM is the same when both props seem to stop.

Due to the interference a very small change of RPM (e.g. 20 RPM) will look totally different on the video. Therefore you cannot deduct anything meanigful from the perceived change in RPM in the video.

I watched a couple videos on YouTube showing Prop Airliner taking off (e.g. DC-6). The effect is exactly the same - direction and speed of the props seem to change through the T/O run.

Well EDML, I'm not going to take the bait! But I'm not sure that a change of only 20 (prop) RPM would look totally different. That would be only one blade per second on a 3-blader, and my pocket camera records at 25 frames per second.

BTW, I gather the RPM on a R2800 at take-off is 2800 RPM at sea-level, but may be 2700 RPM at about 5000 ft. According to Janes, reduction gearing is 0.375 : 1 (3 : 8) - giving prop speeds of 1050 RPM or 1012 RPM respectively (roughly 52 or 50 blades per second).

Farm gate
19th Jul 2018, 01:22
Maybe the left aileron upfloat is due to damage the left aileron primary control cable. (The upfloat changes from the first few seconds, of the latest video, to the 20 second mark, where upfloat is at its maximum, and stays there until impact. An NTSB report regarding a possibly similar occurrence refers. See NTSB ERA11LA117. The left aileron, with what appears to be close to maximum deflection, would make turning to the right on base challenging. With a left engine most likely producing less power in the final minute or so, manoeuvring the aircraft would be difficult. To me the engine note changes, in the video from inside the aircraft, in an attempt to keep wings close to level close to the ground.

sierra5913
19th Jul 2018, 03:40
A post came up on Avherald comments section (publically available). Take it with a grain of salt at the moment.

Convair crash wonderboom. The inside story from my AMO who is doing the investigation is that a fuel line fractured on the carburetor avgas radial left engine. Fire then burned through the oil lines. Loss of pressure prevented them from feathering the prop. They turned right downwind to avoid crashing into built up areas. I.e. Against the live engine. They set it down on base but hit a single story steel and brick warehouse tearing chunks out and bending the i beams at right angles. Probably with an engine. This effectively broke their speed. Landed straight ahead with both wings separating and burning. All 18 pax WALKED OUT! Pilots injured but not sure how badly. Engineer in jump seat went through windscreen and died. Truly lucky for all except the engineer. Pilots were incredibly cool and pax too as reported by my AMO's friend who was on board.

junior.VH-LFA
19th Jul 2018, 04:18
Not familiar with Convair controls, but would a Fire uncontained have the potential to burn through control linkages?

It looks to me like roll was being controlled with asymmetric power till the LH finally died.

What is becoming clear is that this was a feat of good airmanship even with a sad outcome.

roundsounds
19th Jul 2018, 05:36
Other posts have pointed out the deflected aileron from the new vision looking out at the left wing. It does appear to be fully deflected up which means set for a left bank or the opposite to what would would be expected with a left engine failure. Maybe a clue to something worse going on ?

having recently read the reports involving similar accidents for this aircraft type, there was at least one report where the aileron cable was damaged by the heat of the engine fire. Perhaps this is the case here?

GordonR_Cape
19th Jul 2018, 06:17
If you look at a satellite view of the ground track, and the comment posted above, the left aileron was used to turn away from a busy road and densely populated area in the last seconds of the flight. I.e. done under pilot control, no mechanical failure explanation necessary.

4 Holer
19th Jul 2018, 06:24
The fire after shutdown is only excess old and fuel in the manifold and exhaust which is fairly normal after a cylinder head failure. The prop maybe windmilling slightly due the broken piston and probably rod thus lack of x % of cylinder friction. I have seen this before in flight with my own eyes . I suggest this is a normal radial engine failure nothing else.

Maybe the density Altitude and weight got them on the day. Swift recovery to all.

junior.VH-LFA
19th Jul 2018, 06:40
If you look at a satellite view of the ground track, and the comment posted above, the left aileron was used to turn away from a busy road and densely populated area in the last seconds of the flight. I.e. done under pilot control, no mechanical failure explanation necessary.

That much aileron and barely rolling? I'm not so sure about that.

4 Holer
19th Jul 2018, 07:28
Low speed.

EDLB
19th Jul 2018, 08:15
Strange that they could not make it back on one and a half engine. Hope that there is an decent investigation, that others can learn from it.

Overtheditch
19th Jul 2018, 08:52
That much aileron and barely rolling? I'm not so sure about that.

With #1 failed or failing, #1 prop not feathered and #2 producing full power probably I would have thought that merely backing of on right rudder would give a roll to the left easily without the need for much aileron at all. I know, I know. Keep the ball centred and control the roll with aileron is the gospel.

But something is awry here. #1 dead or dying, #1 prop not feathered, Power on the #2 and full down aileron on the left and it appears that it is still banked to the right until the last moments???

DHC4driver
19th Jul 2018, 08:59
The following is a theory, nothing more.... Looking at the video taken by the passenger in the cabin it appears the left hand aileron is stuck close to the full up position (it does not move at all from what I can tell). Normally if the right hand engine was producing more power the left hand aileron would be DOWN if anything. So I imagine they have put in close to full up aileron on the right hand wing to counteract. This would produce significant drag and loss of lift (think spoilers). The only thing left for roll control would be assymetric thrust. At the start of the video it sounds like there is a lot of power on the LH engine, assisting the turn to the right, trying to line up on finals runway 29. When it coughs and splutters with more flames, it loses power, then the left hand wing drops. The only way to stop it banking further left would be to reduce power on the right hand engine, and then they couldnít maintain the height. As previously stated in the video of it after takeoff at the end of the runway there is no evidence of rudder or aileron displacement indicating the LH engine is still producing power at that time. So IF it was an aileron issue it happened further down the track- that may be the reason they never shut the LH engine down because it was the only way of controlling the machine in roll. Thatís my theory anyway. Whatever the findings, it looks like these guys got dealt some really bad cards and managed the situation incredibly well, coming down close to wings level. Hereís wishing a speedy recovery to all involved. So sad.

junior.VH-LFA
19th Jul 2018, 09:35
Low speed.

Any aeroplane Iíve ever flown post V1 with full (or close to) aileron still rolls fairly spritely, even asymmetric.

Aileron input remained constant, yet varying roll rates and angle of bank, ending with a change in sound and seemingly power with a roll rate induced.

i respectfully disagree with you.

Farm gate
19th Jul 2018, 10:08
It appears to me that the loss of left aileron control occurred quite early in the video as viewed from the cabin. Compare the aileron in the first few seconds vs around 20 seconds. At the 20 second point it appears to me that the aileron is full deflection up.

Measuring distance against time, a rough estimate of speed downwind is in the region of 180 knots. I am thinking it was the intention of the crew to make a quick low level circuit for landing, but the fire in the nacelle progressed quicker and more fiercely than the pilots or the onboard engineers thought would occur.

On base the loss of aileron and the loss of power from the left engine combined to make the aircraft no longer flyable.

Indeed in the last 30 seconds, there was a report from the author of the video that the left engine should be shutdown.

Overtheditch
19th Jul 2018, 10:09
Hey guys we can kick this around until the cows come home but suggest waiting for a preliminary report or the like. In the meantime let us focus our energy on hoping for a speedy recovery of Doug, Ross and the other injured. Seems like a marvellous bit of flying here to achieve almost complete survival in what is a very confusing scenario. I will certainly buy them a beer if I get a chance.

Hotel Tango
19th Jul 2018, 10:39
I'm trying to think back of some historical instances where I read that an engine would not shut down. My made up imagination or is that possible?

DaveReidUK
19th Jul 2018, 13:44
I'm trying to think back of some historical instances where I read that an engine would not shut down. My made up imagination or is that possible?

Are you thinking of QF32 ?

Hotel Tango
19th Jul 2018, 14:07
No, I'm going way back in the 50s in the piston era.

EDML
19th Jul 2018, 16:07
I also think that the cable (or one of the cables) for the left aileron burned through due to the engine fire. The airstream / lift will then push the aileron all the way up.

That would make any further right turn more or less impossible. Full right aileron would just have given them a balanced situation. Of course both ailerons all the way up will add quite some drag.

Great airmanship to keep it flying and not crashing doing a snap roll to the left.

BSAA1947
19th Jul 2018, 16:30
Are we not seeing an unusual aileron configuration in the still photo at post 11? It would appear there is a significant upward deflection of the starboard aileron, along with a slight UPWARD deflection of the port aileron too. I'm not sure when that shot was taken, but certainly after the fire had started.

EDML
19th Jul 2018, 19:01
Are we not seeing an unusual aileron configuration in the still photo at post 11? It would appear there is a significant upward deflection of the starboard aileron, along with a slight UPWARD deflection of the port aileron too. I'm not sure when that shot was taken, but certainly after the fire had started.

I think that is an optical illusion. Watching the whole video where that shot was taken from you can see that both ailerons are straight after the aircraft overflew the camera.

EDML
19th Jul 2018, 20:51
Well EDML, I'm not going to take the bait! But I'm not sure that a change of only 20 (prop) RPM would look totally different. That would be only one blade per second on a 3-blader, and my pocket camera records at 25 frames per second.

BTW, I gather the RPM on a R2800 at take-off is 2800 RPM at sea-level, but may be 2700 RPM at about 5000 ft. According to Janes, reduction gearing is 0.375 : 1 (3 : 8) - giving prop speeds of 1050 RPM or 1012 RPM respectively (roughly 52 or 50 blades per second).

Hi Chris,
from what I could find out the reduction gear for the R-2800 is 16:9. With a framerate of the camera of 25fps that would be 2666 engine RPM for the prop to look stopped: (25 RPs * 60 * 16) / 9.
That is pretty much in line with the 2700 RPM for the R-2800 at T/O power.

Hard to tell what that means for the perceived rotation of the prop.

Marcus

EDML
19th Jul 2018, 21:01
Maybe the left aileron upfloat is due to damage the left aileron primary control cable. (The upfloat changes from the first few seconds, of the latest video, to the 20 second mark, where upfloat is at its maximum, and stays there until impact. An NTSB report regarding a possibly similar occurrence refers. See NTSB ERA11LA117. The left aileron, with what appears to be close to maximum deflection, would make turning to the right on base challenging. With a left engine most likely producing less power in the final minute or so, manoeuvring the aircraft would be difficult. To me the engine note changes, in the video from inside the aircraft, in an attempt to keep wings close to level close to the ground.

NTSB ERA11LA117 is a very interesting read. They also had problems with the left aileron after an exhaust fire on the left engine.

https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation/brief2.aspx?ev_id=20110118X45001&ntsbno=ERA11LA117&akey=1

Chris Scott
19th Jul 2018, 22:53
I also think that the cable (or one of the cables) for the left aileron burned through due to the engine fire. The airstream / lift will then push the aileron all the way up.


You may know more than I do about aileron upfloat, its degree and possible effects, but I find it hard to accept that it would be full deflection. Why would a control that is effectively feathered in the airflow be at full deflection and producing a full rolling moment?

Chris Scott
19th Jul 2018, 23:38
Hi Chris,
from what I could find out the reduction gear for the R-2800 is 16:9. With a framerate of the camera of 25fps that would be 2666 engine RPM for the prop to look stopped: (25 RPs * 60 * 16) / 9.
That is pretty much in line with the 2700 RPM for the R-2800 at T/O power.

Hard to tell what that means for the perceived rotation of the prop.

Marcus

Hi Marcus,
You haven't stated your source for a 16:9 engine-to-prop reduction-ratio. Mine, from Janes for 1957/8, giving an engine : prop ratio of 8:3 (i.e., 16:6), would give a prop RPM only two-thirds of yours. Also, we don't know the frame-rate of the video camera used.

You'll agree that each of the three blades is not individually distinguishable. So, with a frame rate of 25 per second, a prop would appear stationary at 25 blades per second (500 prop-RPM), 50 blades per second (1000 prop-RPM), 75 blades per second (1500 prop-RPM) or even 100 blades per second (2000 prop-RPM).

So there's plenty of room for ambiguity, but we would certainly need the camera's frame-rate before postulating from the video. My assumption is that the engine RPMs would have been more or less equal (at about 2700 RPM) as the a/c was getting airborne at the beginning of the video. My GUESS is that the failing port engine was not much slower than the starb'd until the a/c passed over the perimeter fence. After that, it may have started to lose RPM (and therefore propellor thrust) by a significant amount. But I stand to be corrected.

Chris

A Squared
19th Jul 2018, 23:54
Hi Marcus,
You haven't stated your source for a 16:9 engine-to-prop reduction-ratio. Mine, from Janes for 1957/8, giving an engine : prop ratio of 8:3 (i.e., 16:6), would give a prop RPM only two-thirds of yours.

Pratt and Whitney manufactured a whole bunch of different radial engines with 2800 cubic inches of displacement. Some models are pretty dissimilar with no interchangeable parts The engines installed on the Convair were almost certainly either CA series or CB series engines, both of which had a drive ratio of 9:20 or .45:1 Reference is the Type Certificate Data Shees for the respective engine series.

Chris Scott
20th Jul 2018, 00:17
Pratt and Whitney manufactured a whole bunch of different radial engines with 2800 cubic inches of displacement. Some models are pretty dissimilar with no interchangeable parts The engines installed on the Convair were almost certainly either CA series or CB series engines, both of which had a drive ratio of 9:20 or .45:1 Reference is the Type Certificate Data Shees for the respective engine series.

Thanks, A Squared. So 2700 engine-RPM would give a prop RPM of 1215. or about 61 blades per second.

EDML
20th Jul 2018, 01:29
Thanks, A Squared. So 2700 engine-RPM would give a prop RPM of 1215. or about 61 blades per second.

OK, that makes sense as well. Then it would be in sync with a camera with 60 or 30 fps when slightly below 2700 RPM.

EDML
20th Jul 2018, 01:34
You may know more than I do about aileron upfloat, its degree and possible effects, but I find it hard to accept that it would be full deflection. Why would a control that is effectively feathered in the airflow be at full deflection and producing a full rolling moment?

That is because the wing generates lift. The lift trying to lift the wing will also lift the aileron. The lift is stronger than the airstream on the upper side of the wing.

Mach E Avelli
20th Jul 2018, 01:58
In any case the aileron may not have been disconnected - could have jammed either as an unfortunate coincidence, or as result of excessive heating of pulleys, rods etc. Unlike more modern aircraft, that generation did not have control disconnect circuits or back up systems.
It certainly appears that they were faced with a compound failure and probably not one that anyone could have anticipated or would ever train for.

EDML
20th Jul 2018, 02:11
I don‘t think it was jammed. No way to counteract a full or almost full left aileron. If it was jammed the other side would have been full down generating the max. possible roll rate to the left. No way to counteract that. They would have crashed performing a roll to the left.

Mach E Avelli
20th Jul 2018, 06:25
I tend to agree a disconnect is more probable than a jam, but with fire in that area who knows? Possibly the section outboard of the fire had seized and the section inboard had sheared in such a way that remaining controls were still free. Or vice versa. To really confuse matters, the Convair was built at a time when the FAA, or designers, were going through a phase of favouring rudder/aileron interconnects. The CV- 580 had this, and what awful, heavy controls they were, too. If ever there was a contraption it was the 580.
The centred rudder in the video taken from outside the aircraft still suggests close to symmetric power - whether a lot or a little at the time is not so easy to deduce simply from estimating prop RPM. You'd need to know the manifold pressure and TAS to get a better idea.

DaveReidUK
20th Jul 2018, 07:55
Pratt and Whitney manufactured a whole bunch of different radial engines with 2800 cubic inches of displacement. Some models are pretty dissimilar with no interchangeable parts The engines installed on the Convair were almost certainly either CA series or CB series engines, both of which had a drive ratio of 9:20 or .45:1 Reference is the Type Certificate Data Shees for the respective engine series.

As a former USAF C-131D (340-79), it would likely have been fitted with CB series engines (CB3/CB3/CB16/CB17), in which case the reduction gear would be 0.45:1.

Chris Scott
20th Jul 2018, 09:29
As a former USAF C-131D (340-79), it would likely have been fitted with CB series engines (CB3/CB3/CB16/CB17), in which case the reduction gear would be 0.45:1.

Which is, as A Squared noted, 9:20.

DaveReidUK
20th Jul 2018, 11:42
Er, yes, so it is. :\

Bend alot
20th Jul 2018, 12:57
Ok - so a fact as I see it is all on the aircraft, are related to aviation.

The on board video has commentary - "this is bad"

The focus of the guy that knows it is bad with his camera is on what?

Not the aileron but the engine.

EDML
20th Jul 2018, 13:20
Ok - so a fact as I see it is all on the aircraft, are related to aviation.

The on board video has commentary - "this is bad"

The focus of the guy that knows it is bad with his camera is on what?

Not the aileron but the engine.

I would not make any conclusions based on the fact what he is filming.

First of all they had an engine problem from the beginning and secondly the burning engine is a lot more likely to attract attention than the aileron being deflected in an unusual way.

EDML
20th Jul 2018, 13:23
I tend to agree a disconnect is more probable than a jam, but with fire in that area who knows? Possibly the section outboard of the fire had seized and the section inboard had sheared in such a way that remaining controls were still free. Or vice versa. To really confuse matters, the Convair was built at a time when the FAA, or designers, were going through a phase of favouring rudder/aileron interconnects. The CV- 580 had this, and what awful, heavy controls they were, too. If ever there was a contraption it was the 580.
The centred rudder in the video taken from outside the aircraft still suggests close to symmetric power - whether a lot or a little at the time is not so easy to deduce simply from estimating prop RPM. You'd need to know the manifold pressure and TAS to get a better idea.

A stretched aileron cable would also have the ailerons (both sides) deflect upwards. The balanced aerodynamic forces on both ailerons keep them centered while in flight.

Chris Scott
20th Jul 2018, 14:42
....The centred rudder in the video taken from outside the aircraft still suggests close to symmetric power - whether a lot or a little at the time is not so easy to deduce simply from estimating prop RPM. You'd need to know the manifold pressure and TAS to get a better idea.

Any analysis should benefit from the comparison between the performance of the failing engine's prop and that of the good engine which, to state the obvious, is operating at the same TAS. So that leaves the question of the manifold pressure. Your statement implies that the prop pitch could modulate - i.e., become finer - to maintain take-off RPM in the event of failing manifold pressure? In other words, being controlled by the constant-speed function of the CSU.

My only experience of big radials was the Twin Wasp, half a century ago. But my recollection is that, when the pitch levers are set to full-fine for take-off, the propellor pitch is fixed at full-fine and the RPM becomes a function of the manifold pressure as the throttles are advanced to obtain the rated manifold pressure for take-off. (As you suggest, the RPM rises slightly as the TAS increases.) If that's the case, the engine/prop RPMs are directly related to the power available, and in turn the thrust produced by the prop.

It's not until the first power reduction after take-off that the constant-speed function of the CSU comes into play. The throttle is retarded slightly to the desired manifold pressure, followed by the pitch lever. Once the desired RPM is obtained with the pitch lever, the CSU maintains it for a wide range of manifold pressures by varying the pitch of the prop.

Judd
20th Jul 2018, 14:55
This is from a South African friend who is in the industry:


. Anecdotal info is that a fuel line fractured on the carburetor avgas radial left engine. Fire then burned through the oil lines. Loss of pressure prevented them from feathering the prop. They turned right downwind to avoid crashing into built up areas. I.e. Against the live engine. They set it down on base but hit a single story steel and brick warehouse tearing chunks out and bending the i beams at right angles. Probably with an engine. This effectively broke their speed. Landed straight ahead with both wings separating and burning. All 18 pax WALKED OUT! Pilots injured but not sure how badly.

4 Holer
20th Jul 2018, 16:39
The engine put out power at takeoff but was smoking . How about the top cylinder blew head off and broke the prop feathering oil line that runs over the top of it ? Explains trail smoke, engine running for a period, prop not feathering and oil/fuel residual burning in exhaust after shutdown and the windmilling prop. Only a thought....

DaveReidUK
20th Jul 2018, 16:39
This is from a South African friend who is in the industry:

. Anecdotal info is that a fuel line fractured on the carburetor avgas radial left engine. Fire then burned through the oil lines. Loss of pressure prevented them from feathering the prop. They turned right downwind to avoid crashing into built up areas. I.e. Against the live engine. They set it down on base but hit a single story steel and brick warehouse tearing chunks out and bending the i beams at right angles. Probably with an engine. This effectively broke their speed. Landed straight ahead with both wings separating and burning. All 18 pax WALKED OUT! Pilots injured but not sure how badly.

See post #130

A post came up on Avherald comments section (publically available). Take it with a grain of salt at the moment.

Onceapilot
20th Jul 2018, 17:08
.
The centred rudder in the video taken from outside the aircraft still suggests close to symmetric power - whether a lot or a little at the time is not so easy to deduce simply from estimating prop RPM. You'd need to know the manifold pressure and TAS to get a better idea.
I would tend to agree with your observation about the centred rudder showing fairly balanced power, along with the limited deviation of flightpath. Beyond that, it is worth noting that engine operating parameters such as RPM, Manifold pressure etc would not necessarily change with a fuel supply or ignition problem. However, the power output certainly does! In this case, there seems to be a certain amount of popping, banging, oil smoke and flame and I guess the crew could tell which engine was in distress. :uhoh:

OAP

atakacs
20th Jul 2018, 17:28
Was there any kind of data acquisition / recording on board? I understand no FDR in the usual sense but maybe some other device given the engineering related background of the crew?

Chris Scott
20th Jul 2018, 18:36
I would tend to agree with your observation about the centred rudder showing fairly balanced power, along with the limited deviation of flightpath. Beyond that, it is worth noting that engine operating parameters such as RPM, Manifold pressure etc would not necessarily change with a fuel supply or ignition problem. However, the power output certainly does! In this case, there seems to be a certain amount of popping, banging, oil smoke and flame and I guess the crew could tell which engine was in distress. :uhoh:

OAP

Several of us have commented on the apparent lack of rudder (or sideslip) as the a/c passed over the perimeter fence, despite the port-engine failure sequence evidently having started during the latter part of the take-off run. If that is so, the power loss at that stage was minimal. Presumably it developed as the flight progressed, and having to shut an engine down without feathering ability is every piston pilot's nightmare.

Re the relationship between RPM and power/thrust when the throttle and pitch-lever are set at take-off power, I'd be interested if you and others would comment on my previous post. Assuming the flight crew became aware of an engine problem as soon as they were airborne, I think we can assume that the handling pilot would not have called for a power reduction on either engine until they had had a chance to confirm which one was failing.

Onceapilot
20th Jul 2018, 20:09
Re the relationship between RPM and power/thrust when the throttle and pitch-lever are set at take-off power, I'd be interested if you and others would comment on my previous post. Assuming the flight crew became aware of an engine problem as soon as they were airborne, I think we can assume that the handling pilot would not have called for a power reduction on either engine until they had had a chance to confirm which one was failing.

Hi Chris!
The complex relationships between RPM/MAP/Propellor/engine controls etc and Power, could fill many volumes. I cannot contradict your recollections of a Twin Wasp installation. However, I am surprised that you refer to "pitch levers" and CSU, when the control for a CSU is often a RPM control. That said, a VP CSU controlled propellor might sit on it's Fine pitch stop when selected to high RPM at low power on the ground but, will subsequently coarsen as required to contain the selected RPM as power/airspeed allow the RPM to rise to the RPM lever set datum-as is the function of a CSU. Likewise, most CSU will simply reduce propellor blade pitch to accommodate reductions of throttle setting or airspeed (climbing) or engine abnormalities like misfires etc to maintain RPM, unless the engine controls are linked. I do not have type specific knowledge of the Convair, so my comments are limited to the generic behaviour of basic piston CSU.
Best wishes to all involved in this accident.

OAP

A Squared
20th Jul 2018, 21:50
the reduction gear would be 0.45:1.

Is there an echo in here?

DaveReidUK
20th Jul 2018, 22:10
Is there an echo in here?

No, just a mathematically-challenged poster who thought that your 9:20 and 0.45:1 were different ratios. :O

Oops.

What makes it worse is that I teach maths part-time !

Chris Scott
20th Jul 2018, 22:29
Hi Chris!
[...] I cannot contradict your recollections of a Twin Wasp installation. However, I am surprised that you refer to "pitch levers" and CSU, when the control for a CSU is often a RPM control. [...]

OAP

Hi OAP,
Yes: sloppy terminology on my part - on the back of 50 years to forget. :O For "pitch lever", read "propellor-speed control lever."

Re the rest of your post, I won't preempt any welcome comment from others.

Fantome
20th Jul 2018, 22:40
https://upload.wikimedia.org/wikipedia/commons/d/d3/N34---Douglas-DC3-Cockpit.jpg

Why the "P" on the prominent white knobs? (https://upload.wikimedia.org/wikipedia/commons/d/d3/N34---Douglas-DC3-Cockpit.jpg)

Carbon Bootprint
20th Jul 2018, 23:25
https://upload.wikimedia.org/wikipedia/commons/d/d3/N34---Douglas-DC3-Cockpit.jpg

Why the "P" on the prominent white knobs? (https://upload.wikimedia.org/wikipedia/commons/d/d3/N34---Douglas-DC3-Cockpit.jpg)i really donít know these old birds, but from what Iíve gleaned from those wiser than me:

P = propellor pitch
T = throttle/ thrust
M = mixture, itís a piston donk, yes?

Happy to be corrected by those,who know what theyíre talking about, Iím really sorry I missed the era of these flying machines being commonplace,

EDML
21st Jul 2018, 00:04
Correct. In the CV-340 with the Hamilton Standard constant speed props the RPM / propeller handle will be blue.

No idea if all DC-3 had the white handles as most of them had the Hamilton Standard props as well.

megan
21st Jul 2018, 01:48
340 cockpit.

https://cimg6.ibsrv.net/gimg/www.gmforum.com-vbulletin/1050x719/99765_1278641592_e297b19a6980997449288a947cdd3b77a78f7642.jp g

Fantome
21st Jul 2018, 02:33
SOMEONE may have gone "right hand down a bit" a bit too hard ?

Why each side you have two black-knobbed "T" control levers - a long one and a short one?

Capn Bloggs
21st Jul 2018, 03:33
Why each side you have two black-knobbed "T" control levers - a long one and a short one?
Looks like a pair of throttles for each pilot, like the F28. Great system. :ok:

Optical illusion: they look the same length to me.

Fantome
21st Jul 2018, 03:45
So right Cap'n. Left is wide open. Right is closed.

("Wide open" equals "balls to the wall".)

Judd
21st Jul 2018, 04:48
340 cockpit.

Megan. Post 180. I noticed that the instrument panel appears to be missing the captain and co-pilot's artificial horizons. Or am I missing something?

Judd
21st Jul 2018, 04:53
See post #130


DaveReidUK. Thanks for pointing that out. I had not realised it had been posted before. :ugh:

Fantome
21st Jul 2018, 08:46
I noticed that the instrument panel appears to be missing the captain and co-pilot's artificial horizons.

Left panel - directly above altimeter. Right panel - directly below altimeter, is my guess.

Onceapilot
21st Jul 2018, 09:16
i really donít know these old birds, but from what Iíve gleaned from those wiser than me:

P = propellor pitch
T = throttle/ thrust
M = mixture, itís a piston donk, yes?

Happy to be corrected by those,who know what theyíre talking about, Iím really sorry I missed the era of these flying machines being commonplace,


Yes, piston engine. :) It is worth being precise on function of these controls. The P is for propellor speed/rpm (and directly, engine rpm). The propellor control lever does influence propellor blade pitch but, as a function of engine speed control via the CSU, Constant Speed Unit. Although some might feel this is picky, it is important in the safe operation of these aircraft because the function of the propellor in coarser or finer pitch angle can be mis-understood. Whereas, the function of propellor speed lever, generally forward for high propellor/engine speed, is intuitive and similar to the Throttle control action, especially in the low airspeed case where maximum power is often required. The Mixture control action is usually similarly arranged for Rich forwards, as this corresponds to the requirements for full power and so, gives the simple solution for high power in a tight situation of "all the levers forward".
Again, this is a generalisation for this system of engine control and individual installation function and operation must be studied before operating.

OAP

Double Back
21st Jul 2018, 09:53
Yes You single lever thrust control generation :) This is what Yr forefathers had to deal with constantly (and not always with a Flight Engineer) . A wood full of levers and knobs, and indicators/dials all over the place. An artificial horizon that cannot even be recognized as one by modern standards (OK, I have seldom seen such a badly designed one also). No GPS but dead reckoning. 4-engined planes that finished Atlantic crossings at N-1 more standard as exceptionally, or even less...... we came a long way...and thousands of pilots paid the ultimate toll to flatten this road...

Fantome
21st Jul 2018, 10:11
thousands of pilots paid the ultimate toll to flatten this road

Well put DB. What you say is echoed time and again, as a major theme, in FATE IS THE HUNTER. The book is in fact dedicated to a long list of airline pilots, not just Americans, who were part of the process you describe. We who have had a slight taste of these affairs, at a remove, should stand in silent homage to those forerunners. They were cast in many distinctive and differing molds, mostly highly idiosyncratic, with little relevance or connection with operations on the air routes of the world today. (Only the the terrain remains the same and ever ready for the impact of those less fortunate, or less skilled.)

Capt Fathom
21st Jul 2018, 14:23
Well there is a bat and ball on the FO’s side, and a couple of altimeters! That should do nicely!

Onceapilot
21st Jul 2018, 15:20
Although the official definition of the problem that led to this unfortunate incident will come in time, it is worth noting that piston engine failure in service is statistically much more common than with modern gas turbines. For example, the Wartime Rolls-Royce Merlin engine service life was based on only 33% of engines reaching nominal life and the average engine life at failure being 60% nominal life. Better figures than this for a Merlin sub-type would lead to probable engine service life extension! The engine life we are talking for the Merlin in Transport aircraft at the end of WW2 was around 500 hours. I do not know the Service life of the 2800 in the Convair but, I would guess it is a lot longer than the RR Merlin?

OAP

MarkerInbound
22nd Jul 2018, 15:02
As I recall 30 some years back we had a 2400 hour TBO. Maintenance could check the screens and do a valve lash and get a hundred hour extension. We could do that one more time and the engine finally had to come off at 2600 hours. We had several that made to the second extension.

EDML
22nd Jul 2018, 15:54
As I recall 30 some years back we had a 2400 hour TBO. Maintenance could check the screens and do a valve lash and get a hundred hour extension. We could do that one more time and the engine finally had to come off at 2600 hours. We had several that made to the second extension.

Not bad given the complexity and high specific output of those engines.

Onceapilot
22nd Jul 2018, 17:13
As I recall 30 some years back we had a 2400 hour TBO. Maintenance could check the screens and do a valve lash and get a hundred hour extension. We could do that one more time and the engine finally had to come off at 2600 hours. We had several that made to the second extension.
Yes, impressive for big piston engine. I have found top civil Merlin TBO of between 650 and 800 hours in the early 1950's. Don't know the survival rate or average mortality for that TBO. Likewise, I wonder what failure profile R-2800 TBO figures were based on?
OAP

EDLB
22nd Jul 2018, 19:07
They did built 125.000 R-2800 so there where some stats available.

Onceapilot
23rd Jul 2018, 10:39
They did built 125.000 R-2800 so there where some stats available.

Yes, not doubting the figure for the late R-2800, just don't know the criteria used. :) Anyone know the engine failure rates used in civil certification of big piston airliner engine certified TBO?

OAP

aterpster
23rd Jul 2018, 14:55
Left panel - directly above altimeter. Right panel - directly below altimeter, is my guess.
Those don't appear to be AIs. They must have been removed late in the life of the airplane when it was used for VFR only.

fox niner
31st Jul 2018, 20:26
Nowadays, on modern airplanes (twin engine) a climb gradient of 2.4% must be achievable when flying on one engine. What were the certification requirements at the time this airplane was designed?
are the current modern requirements more stringent than they used to be for Convair/DC3 generation airplanes?

Eric Janson
1st Aug 2018, 03:33
The DC-3 was designed to maintain on one engine. This means that whatever height the engine fails at is your circuit altitude if an engine fails on take-off.

Trying to climb engine-out will quickly put you below Vmc unless you are empty. There are several accidents where this happened.

Older aircraft are not certified to current standards.

A Squared
1st Aug 2018, 03:40
are the current modern requirements more stringent than they used to be for Convair/DC3 generation airplanes?

The Convair 240/340/440/C-131 is not the same generation as the DC-3. The DC-3 was a pre-WWII design and the Convair was a post WWII design. There was significant amount of advancement in the intervening years.

Chris Scott
1st Aug 2018, 20:53
The DC-3 was designed to maintain on one engine. This means that whatever height the engine fails at is your circuit altitude if an engine fails on take-off.

Trying to climb engine-out will quickly put you below Vmc unless you are empty. There are several accidents where this happened.

Older aircraft are not certified to current standards.

Your final statement is broadly correct, and probably includes the accident type.

But your first two paragraphs regarding the DC-3/C-47 are sweeping statements, Eric. Goes without saying the performance varies enormously with the conditions, as well as the all-up weight. In a sea-level, UK-based public-transport operation in the late 1960s, we had to demonstrate - following an engine-failure soon after take-off - a climb to circuit height, followed by a circuit, approach and landing. The CofA-renewal air test recorded the rate-of-climb figures on each engine separately. Admittedly these were done at fairly low weights, but the expectation was that the aeroplane was flyable on one engine up to our MTOW of 28,000 lb in temperate conditions. Not that we would have wanted to put that to the test, because we preferred to nurture our old Twin Wasps...

In the same airline group at the same time, to put the above in context, the twin-jet BAC One-Elevens were operating under Performance "A" rules which - as fox niner states above - demanded a single-engine, second-segment climb-gradient of at least 2.4%.

Eric Janson
2nd Aug 2018, 08:31
Your final statement is broadly correct, and probably includes the accident type.

But your first two paragraphs regarding the DC-3/C-47 are sweeping statements, Eric. Goes without saying the performance varies enormously with the conditions, as well as the all-up weight. In a sea-level, UK-based public-transport operation in the late 1960s, we had to demonstrate - following an engine-failure soon after take-off - a climb to circuit height, followed by a circuit, approach and landing. The CofA-renewal air test recorded the rate-of-climb figures on each engine separately. Admittedly these were done at fairly low weights, but the expectation was that the aeroplane was flyable on one engine up to our MTOW of 28,000 lb in temperate conditions. Not that we would have wanted to put that to the test, because we preferred to nurture our old Twin Wasps...

In the same airline group at the same time, to put the above in context, the twin-jet BAC One-Elevens were operating under Performance "A" rules which - as fox niner states above - demanded a single-engine, second-segment climb-gradient of at least 2.4%.

Chris

Of course Performance will vary enormously with weight and density altitude. I'm not disputing that.

I'm not disputing that the DC-3 will fly on one engine - it was designed to. At lower weights it may even climb on one engine - however to the best of my knowledge this wasn't part of the original certification. That is why I used the word 'maintain' - which I believe was also used in the Douglas advertising for the type.

I have had an engine failure in the DC-3. It was cold and the density altitude was very low. With climb power on the good engine I was able to maintain altitude with a speed of 95 knots. The aircraft was well below maximum weight.

The important point is that operating these older aircraft needs to be done with the realisation that they may be certified to different standards. They may not have the Performance margins that more modern aircraft have.

Chris Scott
2nd Aug 2018, 20:02
Yes, I also experienced an engine failure on a C-47 Dakota with 3 tonnes of newspapers and mail on board, but it happened at F/L 70. Hence no need to climb during the diversion. Had the ILS approach through low stratus led to a go-around, however, we fully expected it to be successful.

Eric, you do not need to convince me that the certification requirements for single-engine performance on twins have risen enormously since the DC-3 was certificated in the 1930s, and again since the Convair 340 in the early 1950s. I fully agree that those inexperienced on such older types need to be made aware of that. But there is no need to exaggerate to make the point. You wrote that, in the DC-3/C-47, "Trying to climb engine-out will quickly put you below Vmc unless you are empty."

ChrisJ800
2nd Aug 2018, 21:12
One interesting observation of better modern single engine climb performance is with control zone steps. I used to think of them as step downs but was told that the steps were set by single engine climb performance. For example the steps south of Gatwick have been significantly changed in the last 20 years or so to give higher uncontrolled air space/higher steps as single engine performance is so much better.

Onceapilot
3rd Aug 2018, 22:18
Yes, as is the climb performance when both donks are working! Since you mention Gatwick, one of the standard departures from the westerly runway in the late 1960s (Rwy 27 in those days, since re-designated Rwy 26L) involved climbing straight ahead before a right turn to the east. The turn was to be commenced at a waypoint a certain distance west of the airfield, or passing an altitude of 1100 ft - whichever happened later. The 1100 ft was to ensure terrain clearance in the turn. All the modern aircraft were well above 1100 ft by the time they got to the waypoint. One day I was P2 on our worst-performing Dakota and, heavily-laden, we were clawing our way skywards on both engines but - having passed the waypoint by a mile or two - were still below the 1100 ft. ATC called to ask why we hadn't turned yet (this was long before transponders and Mode-C altitude read-out became compulsory), so we had to remind them about the altitude requirement.

That is a salutary lesson that many should review! :eek:

OAP

B2N2
4th Aug 2018, 04:05
Why do these types of threads always turn into ďwell hereís what I did back then and look at how good I amĒ discussions?
Lets stick to discussing the accidents and itís probable causes.

ACMS
5th Aug 2018, 03:49
So, how are the guys in hospital?

His dudeness
5th Aug 2018, 08:46
Why do these types of threads always turn into ďwell hereís what I did back then and look at how good I amĒ discussions?
Lets stick to discussing the accidents and itís probable causes.

No. Its part of the discussion.

Chris Scott
5th Aug 2018, 15:22
Why do these types of threads always turn into “well here’s what I did back then and look at how good I am” discussions?
Lets stick to discussing the accidents and it’s probable causes.





Yes, it may seem like that at times... The problem is that a rare example of a significant, post-war aircraft has been lost and it appears that no one with experience on type is available and willing to contribute. So old farts like myself with some familiarity of other big-radial airplanes are about as good as you're going to get in advance of the accident report.

Of course there are those on PPRuNe who take exception to any speculative discussion of an accident - see at least one post regarding the JU-52 accident yesterday. My opinion is that we can all learn from (and perhaps even contribute to) the sum of human knowledge in the aerospace field if we are prepared to read and/or contribute with any degree of authority and honesty to such conversations. A significant, if small proportion of our speculative discussions on the possible fate of AF447 were a case in point. Once an accident report has been published, the incentive to contribute ideas is reduced.

In advance of a definitive report almost all discussion is speculative. Cut that out and you are left with photos of wreckage and mawkish expressions of sympathy to the bereaved.

His dudeness
5th Aug 2018, 18:42
+1, Sir.

Keep on posting, please.

FAR CU
5th Aug 2018, 21:37
Thank you Chris. A timely reminder of the benefits of having people of your experience and knowledge being allowed to speak (i.e. post). It is not going too far to evoke the old cliche - "pearls of wisdom". (I thought the MH370 threads were being hampered by the weight of trite comment. In this case the final report begs more questions than it answers. )

There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.
- Hamlet (1.5.167-8), Hamlet to Horatio

Runnymede
8th Aug 2018, 06:27
The fuel type (Avgas v Kerosene) actually pumped into wing during refuelling prior to this flight, is now in question.

It will of course be critical to see what the investigation finds from fuel samples taken.

I mention this because it now appears that both engines were failing / had failed, meaning the right engine was also seen on fire, before impact. That report from an experienced pilot eye witness on ground, close to the crash.

cncpc
8th Aug 2018, 06:32
The fuel type (Avgas v Kerosene) actually pumped into wing during refuelling prior to this flight, is now in question.

It will of course be critical to see what the investigation finds from fuel samples taken.
Well spotted.

Double Back
8th Aug 2018, 06:52
I questioned the refuelled type of fuel quite in the beginning of the thread but my posting was deleted :(
Large airplanes have the risk the refueller automatically takes the Jet A truck... as are planes with "turbo" on the nacelles close to the fuel cap.
Anyway if it will show it was the reason for the crash it will be sickening for all those who got hurt.

Capt Fathom
8th Aug 2018, 07:06
The fuel type (Avgas v Kerosene) actually pumped into wing during refuelling prior to this flight, is now in question.

So who exactly is questioning the fuel type?

Dogma
8th Aug 2018, 08:58
Itís happened to a DC6 before in Botswana... miss fuel ⛽️

The Ancient Geek
8th Aug 2018, 09:34
I find this bit of speculation a tad unlikely, a piston engine fed with a mixture of avgas and kerosene would trail a cloud of white smoke from both engines and a distinctive smell of partially burned kero.
This does, of course, depend on the amount of good avgas in the pipeline and on the mixture percentage in the tanks.

JW411
8th Aug 2018, 11:51
Are you sure you don't mean the DC-4 at Francistown? Not a DC-6.

bront
9th Aug 2018, 02:07
Using Jet fuel doesn't explain the fire.

A Squared
9th Aug 2018, 03:23
Itís happened to a DC6 before in Botswana... miss fuel ⛽️

Happened to a DC-6 in Fairbanks. Alaska. I know a guy who was a witness to the accident.

Using Jet fuel doesn't explain the fire.

In the above referenced accident, the guy who was there told me that as the plane took off, there were long yellow flames coming from the exhaust stacks as the plane took off. He was a mechanic for the airline, so was familiar with what a normal exhaust flame looked like on a DC-6 taking off. That said, the flames in the video appeared to be coming from under the nacelle, not out of the augmenter, which is where I'd expect an exhaust flame to be. On the other hand, running a gasoline engine on jet fuel often results in catastrophic detonation. If it blew the head off a cylinder (which is within the realm of possibility) there would be plenty of engine oil running around loose, heat and sources of ignition. I wouldn't say that the fire in the video is ruling out mis-fuelling.

Airbubba
9th Aug 2018, 04:24
Here's a Martin 404 crash on takeoff after servicing with Jet-A:

libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR70-25.pdf (http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR70-25.pdf)

The FO supervised the fueling, the truck was marked 'Turbo Fuel' and 'JET-A' in big letters. He signed a receipt for 200 gallons of Jet-A and 57 quarts of recip oil for the R2800's.

From the NTSB analysis:

While engine operation was adequate to accomplish a successful take-off with the utilization of the water injection system, the termination of water supply to the engine subsequent to takeoff resulted in immediate manifestation of the detonation and/or preignition conditions. The apparent inability of the flightcrew to recognize immediately the symptoms of detonation, or to assess the cause for this condition, prompted the application of carburetor heat which further elevated induction temperature and contributed to even more adverse detonation condition. Cylinder head temperatures of both engines attained the 300' C. gage limit as a result of the detonation and/or preignition. Again the action taken in opening the cowl flaps, in an effort to rectify this indication, was responsible for increasing drag which adversely affected the critical thrust/drag configuration of the aircraft.

It's been a long time but I remember stopping to drop off a passenger in a bizjet in Quincy, Illinois. The airport was small, not sure if it had a tower and the FBO was the Heetco Jet Center. I bought some fuel (it was indeed Jet-A) and one of the motors was a little low on oil so I ordered a quart. 'Sir, we don't normally stock that turbine oil here at the Jet Center' was the reply.

It seems improbable that the wrong fuel could be put into ZS-BRV with so many aviation types onboard and presumably present at the preflight operations. However, it appears that the plane may have come out of the paint shop a couple of days earlier with the new livery. Was the wrong fuel put on late the night before by a line crew with the Jet-A truck? Or, was the Jet-A inadvertently loaded as ballast fuel before going to the paint shop?

Dan_Brown
9th Aug 2018, 08:52
While mankind has their "sticky little fingers" on anything, mistakes cannot be ruled out. We are a creater of habit and complacency.

This is where computers are superior. Not perfect of course.

When people demand to know, "how can that happen"? Humans.

if the speculation about misfuelling comes to fruition, then it should have been picked up on a pre flight, depending on the mixture of course. Jet fuel would be at the bottom of the tank, would it not? However I appreciate a lot of fuel would need to be drained, into a clear vessel to have any hope of detecting Jet fuel. How often is the sample smelt?

Could have been a catalogue or errors.

Chris Scott
9th Aug 2018, 11:18
Correct me if I'm wrong, but AFAIK there is no suggestion of R/H engine malfunction. Is it being suggested that jet fuel may have been loaded into the L/H wing tank, but not the R/H?

Seems highly unlikely, unless one bowser ran out and then another was deployed.

Volume
9th Aug 2018, 14:58
Maybe they did run the L/H engine a lot during maintenance? An then topped up with Jetfuel?
Enough to cause knocking, not enough to be detected until too late in the takeoff run. Initial issues attributed to water injection by the pilots, but symptoms did not disappear after switching it off?

Normally each engine is fed from one tank only (by regulation), crossfeed is to be used in specific cases only.

Chris Scott
9th Aug 2018, 15:35
Maybe they did run the L/H engine a lot during maintenance? An then topped up with Jetfuel?
Enough to cause knocking, not enough to be detected until too late in the takeoff run. Initial issues attributed to water injection by the pilots, but symptoms did not disappear after switching it off?

Normally each engine is fed from one tank only (by regulation), crossfeed is to be used in specific cases only.
All plausible suggestions, if a tad unlikely. Yes, my comment was predicated on the assumption that the crossfeed would be closed for take-off.

You're right to point out that recently-introduced contaminants take some time to reach the engine. One of my company's DC-10s received seriously-contaminated jet fuel at Lagos in the 1980s. Fortunately, one of the engines started to run down just before they turned on to the runway.

In an ideal world, the water drains at the bottom of the wing tanks are dripped before the first flight of the day, and - as Dan_Brown points out - any kerosene would sink below the gasoline and sit on any water, given the time.

A Squared
9th Aug 2018, 16:57
In an ideal world, the water drains at the bottom of the wing tanks are dripped before the first flight of the day, and - as Dan_Brown points out - any kerosene would sink below the gasoline and sit on any water, given the time.

Well, no, not really. Water settles out because water and gasoline are imiscible. Gasoline and jet fuel mix just fine, and have no tendency to separate from each other. Depending on how much jet fuel was added, and how how much it was agitated as it was added, you might find that the mixture in the bottom of the tank had a greater percentage of Jet fuel than the top, but you aren't going to find a nice clear division, like you will with water and gas that has sat undisturbed overnight.

czarnajama
9th Aug 2018, 21:11
The Hoover Nozzle and Hoover ring are supposed to prevent avgas and jet fuel mixups. Are they used for larger aircraft? Are they used outside the US?

Chris Scott
10th Aug 2018, 00:35
Good point, A Squared.

The Hoover Nozzle and Hoover ring are supposed to prevent avgas and jet fuel mixups. Are they used for larger aircraft? Are they used outside the US?

Do they predate the CV-340? Presumably not. Is the aircraft only refuelled over-wing, or does it have a refuelling gallery for pressure refuelling?

I still don't understand, however, why we are discussing a possible refuelling error in this case.

Capt Fathom
10th Aug 2018, 01:16
I still don't understand, however, why we are discussing a possible refuelling error in this case.
Because there is not much left to discuss.
The refuelling error will go away soon as someone comes up with yet another theory!

sgs233a
10th Aug 2018, 06:39
Good point, A Squared.



Do they predate the CV-340? Presumably not. Is the aircraft only refuelled over-wing, or does it have a refuelling gallery for pressure refuelling?

I still don't understand, however, why we are discussing a possible refuelling error in this case.


Unfortunately, Jet / AvGas fuelling errors have been happening since the dawn of the jet age, and many accidents have happened as a result over the years. There have been measures put in place to minimize risk, but it's still there....and an awful lot of the fuellers don't know one airplane or fuel type from another.

Here are two reports (of much smaller aircraft) misfuelled in Canada in just the last few years:

Aviation Investigation Report A15C0134 - Transportation Safety Board of Canada (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2015/a15c0134/a15c0134.asp)
Transportation Safety Board of Canada - Aviation Investigation Report A11Q0036 (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2011/a11q0036/a11q0036.asp)

With large piston aircraft as rare as they are becoming, the risk of a fueller that has never encountered the type thinking Jet A is required is fairly high. Now, that should be addressed by ordering the correct fuel, placards, hoover rings, vigilant crew, fuel sampling, checking fuel slip, etc. But misfuelling does still happen, and not as infrequently as one might hope.

This may very well not have had any part in this accident at all, until additional information is released, it remains a real possibility.

Super VC-10
10th Aug 2018, 09:23
Does anyone have a reliable, online source for the fuel mix-up please?

mrdeux
10th Aug 2018, 09:30
Does anyone have a reliable, online source for the fuel mix-up please?
There isn't one. This is just something that was thrown up as one of a zillion scenarios....

rog747
10th Aug 2018, 10:46
There isn't one. This is just something that was thrown up as one of a zillion scenarios....

a poster above on here said it was from local hangar disclosure and discussion

The Ancient Geek
10th Aug 2018, 11:32
The facts are simple, EFATO and bitten by density altitude, there may be other contributing factors..
Only one engine failed and no white smoke so misfuelling is a daft theory.

Expect SACAA to release an interim report soon.

Runnymede
10th Aug 2018, 13:10
As I posted earlier (see below) and with all prune type focus (including film from within and external to aircraft) being on the Left Engine smoke/fire = presumed failure, it is now separately in question, yet will be part of any investigation anyway, that kerosene may have been mis-fuelled. We will know from the investigation soon enough.

Further, from external (eye witness report referenced below, who saw Right Engine on fire before impact) and now from one passenger on board (this from a chat at Wonderboom a week ago), it seems the Right Engine was failing/failed also, before impact.

Together, a double eng failure is a horrible day at the office! How it happened C O U L D be explained by fuel Octane rating, Water injection or other reasons unknown. However, that a separate suggestion of missfuelling is now in play, it is plausible that this may be involved. I’m trying to choose my words carefully, for we all know that we don’t know what we don’t know and that this .......... is a rumour mill.........

The fuel type (Avgas v Kerosene) actually pumped into wing during refuelling prior to this flight, is now in question.

It will of course be critical to see what the investigation finds from fuel samples taken.

I mention this because it now appears that both engines were failing / had failed, meaning the right engine was also seen on fire, before impact. That report from an experienced pilot eye witness on ground, close to the crash.

A Squared
11th Aug 2018, 08:24
The facts are simple, EFATO and bitten by density altitude, there may be other contributing factors..
Only one engine failed and no white smoke so misfuelling is a daft theory.

Expect SACAA to release an interim report soon.


Well, I guess we can contact the SA aviation authorities and tell them they can cancel thier investigation, you have it all figured out.

Gigajoules
11th Aug 2018, 16:21
Preliminary report is out... (http://www.caa.co.za/Accidents%20and%20Incidents%20Reports/ZS-BRV.pdf)

atakacs
11th Aug 2018, 18:18
Preliminary report is out... (http://www.caa.co.za/Accidents%20and%20Incidents%20Reports/ZS-BRV.pdf)
Well my completely non-expert take

They were incredibly lucky to have such a low casualty. This was not an emergency landing, just an uncontrolled crash into a dairy factory !
Some admin / paperwork / licensing issues that don't reflect too well on the operation but probably not contributing factor.
No evidence that the right hand engine developed any issue - we are still on the dark as of why they could not maintain altitude. No performance calculation provided.
Nice add for GOPRO...

Airbubba
11th Aug 2018, 18:44
From the preliminary report:

2. Preliminary Findings

2.1 The captain had a valid Australian Air Transport, Commercial and Private Licence and he was type rated on the aircraft (Convair 340/440). However the validation issued by SACAA was for Private Pilot License under visual flight rules (VFR) which was valid until 5th May 2021.

2.2 The FO had a valid Australian Air Transport, Commercial and Private Pilot Licence, however he was not type rated on the aircraft (Convair 340/440). 2.3 The FOís validation of his foreign license was only limited to Single Engine Landing aircraft with the following aircraft types (C150, C172, C182 PA 28 A/B) this is based on his foreign license validation application and skill test report dated 9th of May 2016 and the validation was valid until 05 May 2021.

2.4 The LAME had been issued with aircraft maintenance licence, with the appropriate rating endorsed and was valid at the time of the accident.

2.5 The aircraft is certified for two crew operation, however the engine controls were also operated by LAME who is not part of the crew according to the aircraft flight manual and he is not rated on the aircraft as a pilot.

2.6 The Crew resource management (CRM) in the cockpit was found lacking

2.7 The Aircraft Flight Manual requires two pilots to operate the aircraft and both need to be rated on the aircraft, however the documents and licenses made available to Investigation team indicates only Captain rated on the aircraft (Convair 330/440).

2.8 The aircraft had 2 pilots and 17 passengers on board. Both pilots and two passengers were seriously injured; one passenger (LAME) was fatally injured with 14 other passengers sustaining minor injuries.

2.9 Four (4) persons on the ground sustained serious injuries and another four (4) had minor injuries.

2.10 The owner had sold the aircraft to a Museum in the Netherlands and the aircraft was to be exported to the Netherland on 12 July 2018.

2.11 According to the maintenance records presented to the investigation team, the last maintenance performed on the aircraft was A, B & C maintenance checks on 06 July 2018 at 18115.1 hours, and it was during this maintenance event when the manifold pressure gauge was removed, repaired and refitted to the aircraft. No maintenance test flight was performed after the completion of the scheduled maintenance.

2.12 The aircraft Type Certificate (TC) is held by Transport Canada.

2.13 The crew filed a flight plan of FAWB-FAPN-FAWB and it was granted, however the investigation revealed that the FAPN was closed for maintenance and landing of fixed wing aircraft was prohibited.

2.14 After the e50kts call, the captain indicated that the left manifold pressure appeared to be low.

2.15 The crew were informed of the left engine fire and the master caution light illuminated, however the engine fire extinguishing system was not activated.

2.16 The emergency procedures were not followed after the crew were made aware that number 1 engine caught fire.

2.17 The ATC reported that the aircraft reached 800ft but could not sustain its altitude, and started losing height.

2.16 The Number one engine pressure manifold gauge was defective prior to the accident (on the 26/02/2018 and 05/05/2018) and during take-off roll the pilot reported that the manifold pressure was low.

They had an engine fire but never did the engine fire checklist? :eek:

1.1.17 The GOPRO also shows that the pilots were not sure if they had retracted the landing gears, as they can be heard asking each other whether the gears are out or not. It also shows that though the pilots and LAME were informed of the left engine fire, they were asking each other which engine was on fire. At no stage did the pilots or the LAME discuss or attempt to extinguish the left engine fire, as the left engine fire extinguishing system was never activated.

The following is the procedure which the pilots were required to follow after identifying the engine which was on fire, as extracted from the inflight checklist contained in the aircraft flight manual (AFM):

i. Feather the propeller.
ii. Pull the appropriate fluid shut-off ďTĒ handle.
iii. Close the heat source valves of the burning nacelle with the emergency heat valve disconnect switch.
iv. Place the cowl doors switch of the burning nacelle to the CLOSE position.
v. Place the fuel shut-off valve switch of failed engine to the CLOSED position.
vi. Place boost pump switch of the inoperative engine to OFF position.
vii. With fire extinguisher selector on main, operate the appropriate fire switch; the main CB supply out light, on the fire control panel, should come on.
viii. If fire persists, place the fire extinguisher selector to reserve and operate the appropriate fire switch.

Based on the wreckage examination including the propeller and cockpit GOPRO recording the above procedures were not followed by the crew when the left engine caught fire.

atakacs
11th Aug 2018, 19:09
As they were having a hard time (and eventually failed) to maintain altitude I'd say you try to run both engine as long as possible. Even a failing engine can still produce thrust.
Not sure that was their plan all along but could explain it.

sgs233a
11th Aug 2018, 19:39
As they were having a hard time (and eventually failed) to maintain altitude I'd say you try to run both engine as long as possible. Even a failing engine can still produce thrust.
Not sure that we their plan all along but could explain it.

Depending on it's and the prop's state, could contribute a fair bit of drag rather than thrust, even if still technically running...possibly more than with it shut down and feathered, cowl flaps closed, etc.

A Squared
11th Aug 2018, 19:47
Depending on it's and the prop's state, could contribute a fair bit of drag rather than thrust, even if still technically running...possibly more than with it shut down and feathered, cowl flaps closed, etc.


It would be interesting to know whether the cockpit gopro showed the BMEP gauges and what the indications were. (I think convairs had BMEP gauges, not 100percent sure.

atakacs
11th Aug 2018, 19:57
Depending on it's and the prop's state, could contribute a fair bit of drag rather than thrust, even if still technically running...possibly more than with it shut down and feathered, cowl flaps closed, etc.
Agreed.
Would be interesting to know if it was a deliberate decision (not to go through the fire checklist, and if so why) or if they just froze...

EDML
11th Aug 2018, 20:23
The report also supports our theory regarding the failure of the ailerons I spotted on one of the videos.

The Ancient Geek
11th Aug 2018, 21:26
No mention of misfuelling

voyageur9
11th Aug 2018, 22:17
Both have been heavily involved for a number of years with the Historical Aircraft Restoration Society (HARS) south of Sydney. Together, the aircraft they have flown are the DC3, Caribou, Convair 440, Lockheed Super Constellation, Lockheed Neptune, PBY Catalina plus others.
They have been Senior Check Pilots with Qantas and ....

Given the preliminary report's finding that only the captain's rating included the Convair while the FO didn't have the appropriate type rating, the LAME was handling controls, CRM was lacking and no one followed the engine fire checklist, ... perhaps being Senior Check Pilot with Qantas isn't so impressive or reassuring title for paying pax.

atakacs
11th Aug 2018, 22:32
Not to mention that they were flying to a closed airport...
Still a bit too early to judge their performance

Chris Scott
11th Aug 2018, 22:38
Depending on it's and the prop's state, could contribute a fair bit of drag rather than thrust, even if still technically running...possibly more than with it shut down and feathered, cowl flaps closed, etc.

Yes, it's unclear from the report if the cockpit-mounted Go-Pro showed the RPM and Manifold Pressure gauges, and indeed whether the readings from the L/H Manifold Pressure gauge were erroneous. As previously discussed, the CSU would have tried to maintain the engine RPM even if the available power was very low - and create drag in the process.

Disappointing that the only mention of the video from the empennage-mounted Go-Pro relates to taxiing performance [1.11.1]. One would have thought that it would have shown the L/H engine fire and any anomalies with the ailerons. As it is, we only have the useful photos and videos taken by the LAME's assistant from the cabin after the fire had started.

The report notes that the a/c was repeatedly drifting left during taxiing, and "furthermore, during the review of the GOPRO camera fitted in the cockpit, the captain was complaining about the stiffness of the rudder." But it doesn't explain how the aircraft is steered for taxiing. Are we to infer that the prime method is rudder and, if so, is it possible that the rudder pedals are linked to a steerable nose-wheel on the ground? (This is an example of why we need someone with Convair experience.)

If the L/H propellor was producing little or no thrust (or even creating drag) after take-off, despite the engine still running, a large degree of right rudder would have been required to maintain heading or to turn right. The PF called the PNF for assistance on the rudder, which would be strange if the rudder was fully serviceable. Normally, for readers not au-fait with multi-engine ops, only a small amount of right aileron would have been necessary to stabilise the a/c with a little right bank (towards the live engine), but the report seems to suggest that the PF was commanding a lot of right aileron. However, as EDML points out, the only images we have seen so far show the left aileron deflected upwards, which doesn't make sense unless it was malfunctioning.

Re CRM and the captain's apparent failure to call for the L/H engine fire drill, is it possible that the pilots were in awe of the LAME, who may have been technically far more experienced on type? If so, and having unconventionally delegated engine control to him, they might have assumed that he would take the appropriate action as and when necessary. On the other hand, he may have been waiting for the captain to call for it. That would indeed be a recipe for a kok-up**. The report suggests that the L/H propellor was receiving much less power and/or rotating slower than the R/H at impact, but that no shut down had been performed by the crew. In the absence of any explanation, it seems incredible that, faced with a failure and fire on the L/H engine and an accompanying loss of climb performance, the captain would wish to keep it running

This preliminary report contains minor discrepancies, and there's no mention of fuel analysis as yet.

Airbubba
11th Aug 2018, 22:50
Given the preliminary report's finding that only the captain's rating included the Convair while the FO didn't have the appropriate type rating, the LAME was handling controls, CRM was lacking and no one followed the engine fire checklist, ... perhaps being Senior Check Pilot with Qantas isn't so impressive or reassuring title for paying pax.

Not to mention that they were flying to a closed airport...
Still a bit too early to judge their performance

They didn't have the right licenses, they didn't use the right procedures and they flight planned to a closed airport. Then they crashed the plane. Other than that Mrs. Lincoln, they did a terrific job.

A Squared
11th Aug 2018, 23:11
while the FO didn't have the appropriate type rating,

Was he required to? I have no idea what the SA laws are, but I know that for a non-revenue non-airline flight like this in the US, the FO would not be required to have a type rating, just have received certain type specific training. On the other hand, some countries require a "type rating" in a duchess. I have no idea where South Africa falls in this range.



the LAME was handling controls, Odd for a 2 pilot certificated aircraft, however if it was a DC-6, this is exactly how it would be flown. Without more information, I'd be reluctant to classify this particular aspect and reckless or irresponsible.