Convair 340 (C-131D) ZS-BRV crash Pretoria, South Africa

[Volume]

Bear in mind, there was no mention of BMEP in the report, it's only been a point of discussion in this thread.

Is that another inaccuracy of the (interim) report? Do they actually mean the BMEP when they say "the captain stated that the manifold pressure was low" ?
Do they mean the BMEP indicators when they say "the manifold pressure gauge, which is a dual indicator for the left and right engine, was removed, repaired and refitted to the Aircraft" ?
Does manifold pressure mean anything on these high power piston engines? Is it as important as on a typical SEP with CS Propeller? Or is BMEP the parameter you use to manage engine power?
Is the removed and repaired unit somehow linked to the autofeather system?

[LeadSled]

Originally Posted by Murexway

None of us know what was really going on in that cockpit. We can speculate all we want, but let's wait a bit before we castigate our fellow professional airmen, who are still in the hospital.

Murexway,
Well said, preliminary guesses based on the GoPro and little else will NOT be the whole story.
As for whether the crew were "legal" or not, firstly it has no bearing on the reasons for this terrible accident, and sounds more like a bureaucratic balls up than anything else, to me. Nowhere (but particularly in Australia) is aviation law straight forward and unambiguous.
Tootle pip!!

[rog747]

good news is one of the pilots (Doug) has been repatriated home by QF

also one of his QF colleagues has stated the pilots were def typed rated for the a/c (Ok but maybe not for flying in RSA as reported?)

please see the thread on the pacific forum for more details re the pilots and news

Douglas Haywood and Ross Kelly

[Dan_Brown]

Originally Posted by Grizzly Bare

First iteration:
"Sorry, our documentation is not yet in place, so we can't legally fly yet."
That night everyone is still alive.

Professional airline pilots know when they are legally allowed to fly, and know when they can't. Many thousands of birthdays/anniversaries have been missed because crews have reached duty limits and can't fly home in time - even though they desperately wanted too. QF pilots would not deliberately bust mere duty hours to get home, and yet this flight happened in Africa. This is so much a worse violation. An attitude of "I don't have the legal authorisation to fly this airplane in this country on this registration, but what-the-hell I'll violate the law and do it anyway, it's only South Africa - not like it's a real country and a real CAA" by any chance?

"Let whom without sin cast the first stone"

[sycamore]

Can anyone confirm whether the aileron controls are cable ,or pushrod operated.Also a`routing` diagram along the wing/fuselage would be useful...

[steamchicken]

Originally Posted by A Squared

As I said in a previous post, its really a torquemeter. The way it measures torque is the outer ringgear of the planetary gear reduction unit has helical splines around it's rim. These fit into helical splines in the nose case of the engine. the reaction to engine torque tend to shift this ring gear backward (Or is it forward?, it's been a while) opposing that axial thrust are a series of hydraulic pistons which operate off engine oil pressure from the nose case scavenge pump. there's some sort of metering mechanism so that the pistons exactly offset the axial thrust of the ring gear, and the actual measurement is of the oil pressure required in the pistons to balance that axial force, the signal from the oil pressure transducer is displayed on the BMEP gauge. As a side note, on other radial engine installations, the torque meter was calibrated in units of "Torque oil pressure" which is a more accurate description of what is actually being measured that BMEP, But again, the units are arbitrary, learn what numbers you should see for what power setting on your engine and it doesn't matter the actual units are.

Originally Posted by MarkerInbound The autofeather system is armed by raising the guard and then the switch under it found at the center of the pedestal aft of the prop controls. There is one green light to the left of the switch that indicates the system is armed. When the throttles are advanced to a point that equates to ~45 inches MAP and the BMEP drops below ~70 for more than one second a solenoid pulls the feather button in and the prop feathers as if the feather button was pushed. The system also then disarms to prevent autofeathering the other prop.

And to think there are people on here who talk about the simple aircraft of the 1950s!

[junior.VH-LFA]

Originally Posted by Grizzly Bare

First iteration:
"Sorry, our documentation is not yet in place, so we can't legally fly yet."
That night everyone is still alive.

Professional airline pilots know when they are legally allowed to fly, and know when they can't. Many thousands of birthdays/anniversaries have been missed because crews have reached duty limits and can't fly home in time - even though they desperately wanted too. QF pilots would not deliberately bust mere duty hours to get home, and yet this flight happened in Africa. This is so much a worse violation. An attitude of "I don't have the legal authorisation to fly this airplane in this country on this registration, but what-the-hell I'll violate the law and do it anyway, it's only South Africa - not like it's a real country and a real CAA" by any chance?

Knowing that they were both (clearly) trained on type, you are focusing on easily the most irrelevant and insignificant aspect of this tragedy, paperwork on the day wouldn't have stopped what happened from happened. For what purpose or agenda remains to be seen.

[Volume]

The flight crew were not licenced to pilot this aircraft. Simple.

Really simple? Are there still training organisations around which have instructors current on this type? Are there training aircraft available? (approved) Flight simulators? Are there any examiners current on the type? Is the manufacturer maintaining the training material up to date? Or even the pilot handbooks? Does the licence mean anything?
It might be a pure beurocratic paperwork issue, you can probably have pilots which can perfectly handle such aircraft but are lacking the paperwork, you probably can also have pilots perfectly licenced but havin no clue how to operate them.
For 1950s vintage aircraft it does not make much sense to aply 2018s regulation for flight crew licencing.

So it is a simple fact with a difficult truth behind...

[climber314]

[QUOTE=The Ancient Geek;10193854]The SACAA can be relied upon to publish a full investigation is due course, their work is always to a very high standard.
/QUOTE]

Paperwork seems to be a legitimate concern.
CRM is another issue, as is NOT running the EFTO/Fire Checklists amongst others.
A GoPro video is a pretty good substitute for the lack of CVFDR in this incident.
What is the alternative theory here?
That SACAA has it "in" for the crew due to a regulatory issue?
Seems like an unbiased and fact-based PRELIMINARY report IMO.
It appears some here don't like the facts as presented by SACAA?

[Feathers McGraw]

Something from the other thread that I had not seen mentioned before

https://www.pprune.org/australia-new-zealand-pacific/611016-douglas-haywood-ross-kelly.html#post10195432

It is stated that the FO on the accident flight, Ross Kelly, had an engine failure in another Convair last year. So one of the flight crew had first hand experience of the CV-340 on one engine even if at a very light weight.

Not sure how that would manifest itself in this case, but surely better than having no experience of engine problems.

[Murexway]

Originally Posted by Volume

For 1950s vintage aircraft it does not make much sense to apply 2018s regulation for flight crew licensing.So it is a simple fact with a difficult truth behind...

Well, it's true that regulations can't prevent accidents, but they're the best thing we have (in addition to currency) to try and insure that the people flying the airplane have some familiarity with what they're doing.

I must say that after reading the preliminary report twice, and looking at what the result was, it's hard to understand why nothing was apparently being done in the cockpit other than to try and maneuver the airplane back to the field. It's especially baffling in light of the fact that both gentlemen are very experienced A380 captains and one of them is apparently a check airman - a training captain, and they apparently ferried the same type aircraft to Australia previously.

The A380 is a marvelous aircraft, but with all of today's automation and heavy reliance upon flight management systems, do the old, basic flying skills and mindset erode?

[Murexway]

Originally Posted by sycamore

Can anyone confirm whether the aileron controls are cable ,or pushrod operated.Also a`routing` diagram along the wing/fuselage would be useful...

Cable operated. Someone may have already posted this, but here's a link to a left engine fire incident on a C-131F. The report noted... "The examination revealed significant heat damage to the rear spar of the left wing, and to a flexible hose associated with the left brakes. Additionally, the left aileron primary control cable was noted to be drooping."

https://www.ntsb.gov/about/employmen...11LA117&akey=1

[climber314]

Originally Posted by Feathers McGraw

Something from the other thread that I had not seen mentioned before

https://www.pprune.org/showthread.php?p=10195432

It is stated that the FO on the accident flight, Ross Kelly, had an engine failure in another Convair last year. So one of the flight crew had first hand experience of the CV-340 on one engine even if at a very light weight.

Not sure how that would manifest itself in this case, but surely better than having no experience of engine problems.

So is there an ATSB TRANSPORT SAFETY REPORT on the Engine Failure Incident with VH-TAA mentioned?
It would seem VERY relevant given this incident IMO.

[A Squared]

Originally Posted by Volume

Is that another inaccuracy of the (interim) report? Do they actually mean the BMEP when they say "the captain stated that the manifold pressure was low" ?
Do they mean the BMEP indicators when they say "the manifold pressure gauge, which is a dual indicator for the left and right engine, was removed, repaired and refitted to the Aircraft" ?

There's nothing which suggests that mix up. I only pointed out that the BMEP wasn't mentioned in the report to keep readers from assuming that our discussion of BMEP gauges indicated there was reason to believe that there was a problem involving BMEP.

Originally Posted by Volume

Does manifold pressure mean anything on these high power piston engines? Is it as important as on a typical SEP with CS Propeller?

Yes, it is every bit as important as it is on a simpler, normally aspirated piston engine with a CS prop. MAP is the primary indication for setting power.

Originally Posted by Volume

Or is BMEP the parameter you use to manage engine power?

Not really, power settings are made by MAP and RPM. BMEP is useful as it is a measurement of output, vs MAP which is a measurement of input. Input doesn't necessarily equate to output, depending on condition of the engine, etc. As an example, if you were to turn off the magnetos in cruise in the DC-6, the RPM would tend to remain the same because of the CS prop. MAP is a function of supercharger speed and throttle opening, and because the RPM is the same and you haven't changed the throttle setting, MAP indication will remain the same. and fuel flow would remain the same. But obviously, even though you have the same manifold pressure, you aren't getting the output you want. Aside from aircraft feel/handling/performance, the only instrument indications of the power loss would be BMEP and your cylinder heat temps would be decreasing. BMEP was used to verify power output, and on the DC-6, if you had the same MAP and RPM on all 4, and one BMEP was noticeably lower than the other 3, that was an indication something wasn't right. Also, BMEP was used as a primary indication for leaning the fuel mixture in cruise. We would lean until BMEP peaked, then decreased by 12 psi. That represented about a 10% drop, when meant we were operating Lean of Peak, but that's a whole separate discussion.

Originally Posted by Volume

Is the removed and repaired unit somehow linked to the autofeather system?

Not exactly, as I said, there's no indication that the references to the MAP gauge were in error. There's no direct link to the Autofeather System, so an MAP gauge error wouldn't affect the operation of the autofeather system.

[A Squared]

Originally Posted by steamchicken

And to think there are people on here who talk about the simple aircraft of the 1950s!

Yeah, ain't that the truth. Having flown in all 3 seats of the DC-6, there was nothing simple about that airplane ... or aeroplane, as you like ...

[Feathers McGraw]

Originally Posted by climber314

So is there an ATSB TRANSPORT SAFETY REPORT on the Engine Failure Incident with VH-TAA mentioned?
It would seem VERY relevant given this incident IMO.

I had a look around the ATSB site but I have not found anything about it. Bulletins seem to be only up to mid-2017, maybe it will be in a later one.

[PAXboy]

Let me throw a hand grenade: Are we going to keep restoring and crashing these machines - until there are none left? Since the Convair there was the Ju-52.

It was my late father who asked this question when the last airworthy Beaufighter went in. He was in Beaufighters and Mosquitos for 4.5 yearsin WWII and thought it better to have something original to show the next generation rather than reproductions.

[A Squared]

Originally Posted by PAXboy

Let me throw a hand grenade: Are we going to keep restoring and crashing these machines - until there are none left? Since the Convair there was the Ju-52.

It was my late father who asked this question when the last airworthy Beaufighter went in. He was in Beaufighters and Mosquitos for 4.5 yearsin WWII and thought it better to have something original to show the next generation rather than reproductions.

Ehhh, it's not like we're talking about a rare, priceless historical artifact. There's rows of them sitting in the desert. We're a loooong way from running out of Convairs.

[Chu Chu]

If the aircraft are fully documented (a big if, I know), we don't really lose much knowledge if one goes in. Certainly, looking at photos is not the same as walking around an aircraft in a museum. But to me, walking around one doesn't hold a candle to actually seeing it fly. Obviously a there's a trade off to be made, but I'd say we'd lose more than we'd gain from a strict prohibition on flying historic aircraft.

[Centaurus]

BMEP was used to verify power output, and on the DC-6, if you had the same MAP and RPM on all 4, and one BMEP was noticeably lower than the other 3, that was an indication something wasn't right

The operative word is "noticeably." In the Convair (assuming my memory is correct from over 50 years ago since I flew the Convair 440) there was usually around 15 BMEP difference between the two engines on take off. That was because one of the engines was used for operating the air-conditioning /pressurisation systems and that stole power from that engine, for want of a better term. I forget which engine. However manifold pressure and RPM indications displayed equal for both engines. It was only the BMEP for one engine that was slightly down on the other engine