Crash-Cork Airport

[mad_jock]

Its as good an excuse as any to read up on the engines. I try and do a sub system per month system revision anyway.

[NigelOnDraft]

mj

I've re-read the 2 sections of the report. My understanding of what they are saying:

1. The Temp sensor fault in #2 engine gave it higher fuel flow than #1 for matched power levers
2. Not an issue for normal Ops, albeit crews were seen to match Tq in cruise
3. From about -9s to -6s Beta range had been selected
4. Due to the Temp sensor this led #2 to 0% Tq, #1 to -9% Tq
5. #1 (not not #2) therefore triggered NTS, and (only started to?) feathered prop - seen by an increase in Tq to +22% and RPM drop
6. Manual states selecting Beta in the air can cause loss of control due drag / asymmetry - no doubt even more so given the mismatch as above
7. NB one Beta interlock still found operated after crash, albeit a little movement and it "popped" back.

From my reading, if either Beta had not been selected, or possibly the sensor fault had not been present, the accident would not have occurred in this manner. Of course, other single event factors could also have prevented it, let alone the complete chain.

I see no implication from the report that the crews' skill (or not) were a factor in the loss of control i.e. given Beta/Sensor fault, the aircraft was "maybe/likely/probably" uncontrollable.

Clearly open to thoughts from those more familiar with TPs as to my misunderstandings or thoughts on what the report has said.

NoD

PS ATPL ~14Khrs, skim read 244 pages, detailed / multiple read of ~100 pages

[mad_jock]

The torque is a function of the propeller load. Not engine output which can only be worked out using rpm and fuel flow (which isn't recorded on those FDR's)

So when the engine is providing power either in reverse(beta) or forward it is a positive value.

If the airflow is driving the propeller its is a negative value.

So when you move the power levers on the ground during an engine run from fully forward to full reverse at 100% rpm the torque will start at 100% then reduce down to zero and then increase again up to about 30%.

The only thing which feathers the prop is the huge spring inside the hub you need positive oil pressure to stop it feathering.

I don't know about the metro but there is a very loud trill beta horn on my type which is operated by a microswitch on the pedestal for power lever position. And the only mention of alarms was the stall warner.

If the plane is horrendously rigged it is possible to get extremely low values of flight idle and negative torque.

The flight idle check is descending between 10k and 6K, flows off anti-ice off rpms 100% and then the power levers back to touch the gate at 140knts(might be a different speed I use a briefing sheet when I do it). Normal values are between 4 and 8%.

I have picked up a plane out of maint where the flight idle went down to -5%torque with the other at 10% which caused a lot of swearing when I got back and the plane in the hangar for 2 days getting re-rigged then another test flight. In general the more experienced you are on these types the lower you prefer the flight idle but -5% is a bit to much even for me even if both sides do it. You can quite happily be at 250 knts at 6 miles on a 3 degree glide and be back at 130 approach speed by 3 miles and hit your 500ft stabilised gate if the flight idle is about 4%.

So just from the torque readings I don't think you can read anything into if the power levers were brought back behind the gate or not. So just because its reading negative torques doesn't tell you where the power levers were. It all depends on the rigging. As for one of the gates being up I don't know what I would grab onto during a crash to try and brace myself.

You get to know individual aircraft as well and the old girls gotchas and I see they had just swapped to the standby aircraft. It could be that the normal one was rigged properly and in the heat of the moment he forgot that this ones flight idle was way out.

It would be interesting to know if a proper flight idle check was done after the heavy landing maint. I can only presume they had the engines out during that to check the main spar. There is no requirement to do a flight idle check on our type after an engine swap but a limitation is placed in the tech log "not to be used for training"

AT 6k hours and 5000ish hours on TP331's

[NigelOnDraft]

mj

So just from the torque readings I don't think you can read anything into if the power levers were brought back behind the gate or not. So just because its reading negative torques doesn't tell you where the power levers were.

I think we are at cross purposes here - have you read the report?

They are quite clear the power levers and the props went to Beta. I'm not going to repeat their findings / reasoning, but they are clear.

[mad_jock]

yes I have read the report.

And appendix L covers it.

The assumptions are taken from a brand new engine sitting on a test bed. Supplied by Honeywell who are getting there backsides sued off. Analysis done by an engineer who more than likely has never sat in a Metro never mind flown one.

If they had the actual fuel flows it might be more creditable.

But any one who has actually operated these engines in the old heaps they are fitted to can tell you that you can get negative torques in flight with the power levers forward of the beta gate depending on what the flight idle fuel flow is set at. I have lost count how many aircraft I teched because of flight idle being to low and going negative. Most of the time the NTS doesn't fire either as it takes 2-3 seconds to kick in and something like 85lbs of force on the actuator ring what that translates to in neg torque I don't have a clue.

These engines are not some fedec controlled monitored cross checking bits of kit.

They are an analogue control system with I think 16 different variables which the engineers have to tamper with to get them set up. Of course every time you change one variable it changes all the rest. The engineering term I believe is "utter bastard" but they give you a 20% fuel saving over the PT6 free turbines.

So the Honeywell engineers might like to believe they know where the power levers are and what mode the engines are in but any experienced user of the engines/props will tell you its a bit of fanciful make believe after the engine has been on the wing a couple of thousand hours after a hot section to be able to get anything useful from just rpm and torque.

Its pretty easy to set up on the engines you just need to turn the flight idle fuel flow back by 12 "clicks" on an engine set at 4% flight idle and you will get your -9% but then you won't get 100% torque for TO.

[BARKINGMAD]

244/244 pages read!

Surface temp/ dew point +5/+5 at elevation 502 feet.

If airmass was saturated, then the temp at 3000ft, 2500 above field elevation may have been approx +1.25 degrees, assuming lapse rate of 1.5/1000ft.

The aircraft was in this airmass for over 50 mins prior to the 3rd approach.

Any TP operators like to educate an ex-turbofan driver of the likelihood of engine icing in such conditions which might affect the Garrett?

I assume the investigation has looked at this but I have failed to find, or have missed, any reference to the possibility.

[mad_jock]

you have eng anti ice heaters which take air from the second turbine stage. There is a slight performance penalty due to increased egt for departure but nothing for landing or go-around.

I but its a good point because I didn't see anything about the flows settings.

Normally engine anti ice is on at +5 and off at +10 with visible moisture.

This isn't recorded in the FDR if you have them on or off.

Normally it gives a 10-20 degree increase in egt at cruise levels. At 5 degrees you will be torque limited not egt limited so will have 100% torque available with it turned on but the torque increase rate will be slightly less but nothing really noticeable.

[Livesinafield]

Sorry but I disagree...

This mode of operation might be distasteful to some, but as the report and subsequent to the accident shows, is perfectly legal. The CAA picked up Manx2 on some minor website breaches which they corrected, and the CAA continued oversight with seemingly no concern.

EASA and the Spanish CAA bear the responsibility for the "two bob tin pot operation" not being open to UK / Irish scrutiny. It's what our politicians have signed up to... and at heart that is where the basic cause lies, and I doubt will be changed.

In summary, what do you find Manx2 have done either illegally, or even just immorally?

Nothing i suppose, but anyone in their right mind wouldn't step withing 5 feet of a Citiwing/Manx2 flight

i have refused to allow my company to fly me on these flights in the past.....

[Sunnyjohn]

The accident Flight Crew … commenced duty at EGAA at 06.15 hrs (and) downloaded flight documentation including meteorological information for Belfast City Airport (EGAC), Cork Airport (EICK) and Dublin (EIDW) in a handling agent's briefing office at 06.25 hrs.

Correct, but: (report, p 142)

in any case, a departure was made without the Flight Crew having adequate information and a clear understanding of the overall weather conditions.

which I think was in my mind when I made my previous comments.

[Bang Or West]

Sunnyjohn - I did actually see the paragraph you refer to on my first reading of the whole report (on the day it was released). It's one of the few parts of the report that initially made no sense, particularly with respect to what is written elsewhere.

However, I then re-read page 115, and it all made sense! Page 142 states that "In any case, a departure was made without the Flight Crew having adequate information and a clear understanding of the overall weather conditions". Read this in the context of Page 115 where we learn that "The evidence indicates that the Flight Crew were unaware of the forecast and actual weather conditions for their nominated alternate airport EIWF and both EINN and EIKY".

The "adequate information" referred to (or lack thereof) clearly relates to the lack of METAR or TAF for the alternate, or points beyond. I'd love to know what B-plan they were working to...assuming they did have a B-plan, didn't they?

[mad_jock]

This is another argument which is quite common with these sort of types of operation especially when tankering fuel.

You actually need two more alts and so load fuel for them or have enough in the tanks to get back to where you started from.

But..

Its a pain in the arse to get another plog printing it and even getting it and it will 9 times out of 10 make you late and ops is reluctant to generate you another one especially so if you paying a third party to produce them as they will charge an additional fee.

And if the crew think its normal to just choose one or two alts that work they tend to over look the requirement for the Alt to be with in 1 hour single engine speed to not contravene that regulation.

You can explain this to guys that have been in the game for 10-20 years that they need to have a PLog and flight plan for what they are actually planning and they just look at you and tell you to stop talking rubbish and walk off. And any comment that we don't have ETOPS approval is met with an equally blank look. And you only have to look at the number of TP aircraft going straight across the Bay of Biscay to realise that the 1 hour single engine is pretty much ignored.

[mad_jock]

Well if you have fuel for the furthest one you will have it for the nearest one won't you.

But that outstanding you need to have the ones your actually using nominated on your log and flight plan and not just say it here is alright I have round tripped my fuel so we will come back here if we can't get in and you cruise at 230knts for an hour to destination and your single engine cruise speed is 150knts. And on your log and flight plan you have alts which are 60 miles away from destination showing 400m rvr. Or neither are open yet and there is no TAF available just a AUTO METAR saying the wx is OK.

Even if you do get in if you get SAFA checked and they do there job properly you will get your arse in a sling quite rightly.

[Sunnyjohn]

Sunnyjohn - I did actually see the paragraph you refer to on my first reading of the whole report

Thanks for the clarification, Bang Or West. It's a very detailed and thorough report and does take a lot of reading and digesting!

[deefer dog]

Forgive me, but did lack of fuel cause the accident? Was there any mention in the report that they did not meet the fuel planning requirements?

Which part of this accident is not understood by so many here? They busted their minimums three times, and ran out of luck on the third attempt.

This is not unlike the more recent accident at KASE where it would appear (subject to the final report being published) that the crew attempted to land while exceeding the certified limits of the aircraft.

[Jack1985]

The aircraft had 3,000lbs before departure from EGAC, more then sufficient for the aircraft to operate to EICK and back to EGAC.

I think trying to rule this down to one single cause, is what will actually see this accident happen again - there is never just one cause, its a series of ones which combine together to cause the accident and its from these from which we should learn.

The fact the No. 1 was retarded on the 3rd final approach also significantly contributed - As did the fact they were fatigued and there were numerous other factors, a statement of ''oh he bust the minima 3 times'' would be an insult to the investigation team of this accident.

As has been advised previously, please read all 244 pages.

[kapton]

Jack 1985 has it spot on about there being more than one cause to this accident. The professional pilots give an invaluable insight into the handling and operation of the aircraft during this tragic event, but I look at it from the angle of all the holes in the cheeses lining up. The pilots involved in this accident did not take off that morning with the intention of making the mistakes which led to the crash. I watched the Manx2 operation from the outside and was appalled at what I saw. Here was a collection of companies who we're doing everything on the cheap whilst giving the impression of being an airline.
Moreover, some of the people who worked for the operation were desperate to work in aviation, which, is one of those holes already lined up before you start. Almost every aspect of the operation was at fault. From the people who set the operation up the way they did, to avoid costs, to the various regulatory authorities, who knew the setup, but sat on their hands hiding behind EASA regulations.
In full view of people who ran the operation, pilots had periods when they weren't being paid, and even carrying out maintenance tasks. In 2 parts of the operation the maintenance back up so woefully inadequate that it was criminal. I think it will be some time for this report to be fully understood, if only for the incredulity one feels when reading it. It is for the lawyers and courts to decide whether legal sanction is taken against certain individuals. But, EASA need to stop existing to issue edicts and regulations, and act now to shut down operations such as what was manx2. Those who died, and their families, deserve that at the very least.

[His dudeness]

In 2 parts of the operation the maintenance back up so woefully inadequate that it was criminal.

I watched the Manx2 operation from the outside and was appalled at what I saw.

Are you saying you watched criminal behaviour and did not report it ?

Just asking....

But, EASA need to stop existing to issue edicts and regulations, and act now to shut down operations such as what was manx2.

In full view of people who ran the operation, pilots had periods when they weren't being paid, and even carrying out maintenance tasks.

So if I as a private person or as a company would charter an airplane from an AOC holder I would have to check their crews paycheck, the mx records and their operational procedures or lack thereof ?

There I was thinking that this what we have aviation authorities for....

[deefer dog]

The aircraft had 3,000lbs before departure from EGAC, more then sufficient for the aircraft to operate to EICK and back to EGAC.

I think trying to rule this down to one single cause, is what will actually see this accident happen again - there is never just one cause, its a series of ones which combine together to cause the accident and its from these from which we should learn.

The fact the No. 1 was retarded on the 3rd final approach also significantly contributed - As did the fact they were fatigued and there were numerous other factors, a statement of ''oh he bust the minima 3 times'' would be an insult to the investigation team of this accident.

As has been advised previously, please read all 244 pages.

I did read every page of the report. The accident would not have happened if the crew had not busted the minimums. Which bit of that is not clear to you, or the investigators (if they happen to be reading).

[NABLAG]

Question: If the crew had complied with the Cat 1 minima (200 ft AGL ?) and the Captain had handled the power in the same way would the crew have enough height to recover ?

[Sunnyjohn]

The accident would not have happened if the crew had not busted the minimums.

From what I have read, and I have read the whole report, I don't see how you could know that. Could you explain?