A340 vs wall - wall wins

[Kip Powick]

Question for Mitch.............

Are "our" guys trained to stop a runaway, ie max brakes, max reverse etc if something like this happens during a run-up?

The reason I ask is that the one photo, (taken from the air), shows that the aircraft did travel a fair ways before impacting the blast fence and based on its resting position it would appear that the bird was at a very high power setting when it "climbed" the wall. As well, it doesn't look like any of the engines had "reverse thrust" applied at impact...........unless they did a good post landing check before shutdown

Edit

13 SECONDS BEFORE THE IMPACT THE AIRCRAFT STARTED TO MOVE. WITHIN 1 OR 2 SECONDS THE CREW APPLIED BRAKE PEDAL INPUTS AND SELECTED PARKING BRAKE OFF. THESE ACTIONS LED THE NORMAL BRAKE PRESSURE TO INCREASE TO ITS NORMAL VALUE.

2 SECONDS PRIOR BEFORE THE IMPACT, ALL 4 ENGINE THRUST LEVERS WERE SELECTED TO IDLE.

THE AIRCRAFT IMPACTED THE CONTAINMENT WALL AT A GROUND SPEED OF 30 KTS.

Wow...ten seconds is a long time to be sitting in the cockpit with the aircraft moving and no one reralizing that perhaps they should reduce to idle or select reverse

[mrlupin]

Question for Mitch.............

Are "our" guys trained to stop a runaway, ie max brakes, max reverse etc if something like this happens during a run-up?

The reason I ask is that the one photo, (taken from the air), shows that the aircraft did travel a fair ways before impacting the blast fence and based on its resting position it would appear that the bird was at a very high power setting when it "climbed" the wall.

Good day kip,

The training is being reduced by Air Canada. While a 320 run course used to include 8 hours of sim time, with almost all possible ground situations covered, the training has been cut in half.

Our union regroups so many various trades (station services,stores,powerplant,shops etc)that asking for their help in these issues (with the company reducing training) is pointless. The people running the union wouldn't even understand the issue. Transport Canada has some guidelines but they are low so AC has no problem meeting them so help will not come from TC or the union....

Just as an example, Boeing gives a 777 maintenance course and it's duration is 9 weeks. Air Canada gives the same course and it's duration is 6 weeks.

[Kip Powick]

mrlupin

Hmmmmmm gives one pause.......hopefully it doesn't take an incident like this to spur on AC to get its house together.

[Mitch Cronin]

What Eric says is right on... Our recurrent run "training" now is done on live a/c... obviously with no opportunity to brush up on actions in the event of various failures...

...so I can only speak of the training I originally recieved... and yes, ALL imagineable failures were trained for in the simulator... including brake failures at high power, etc... Up until a year ago, or so(?), recurrent training was still done in the simulator and we'd have to renew our run-up and taxi tickets every so often on each type we were endorsed on.

My guess is that in the game of risk management and bean counting, this A340's beans won't ever get counted.

...and you're right Kip... ? I can't imagine why those 10 seconds would have elapsed...

[Moon The Loon]

FOR ABOUT 3 MINUTES BEFORE THE END OF THE EVENT, ALL FOUR ENGINES EPR WAS BETWEEN 1.24 AND 1.26 WITH PARKING BRAKE ON AND WITHOUT GROUND CHOCKS.

THE ALTERNATE BRAKE PRESSURE WAS NORMAL. (WITH PARKING BRAKE ON, BRAKE PRESSURE IS SUPPLIED BY ALTERNATE).

13 SECONDS BEFORE THE IMPACT THE AIRCRAFT STARTED TO MOVE. WITHIN 1 OR 2 SECONDS THE CREW APPLIED BRAKE PEDAL INPUTS AND SELECTED PARKING BRAKE OFF. THESE ACTIONS LED THE NORMAL BRAKE PRESSURE TO INCREASE TO ITS NORMAL VALUE.

2 SECONDS PRIOR BEFORE THE IMPACT, ALL 4 ENGINE THRUST LEVERS WERE SELECTED TO IDLE.

THE AIRCRAFT IMPACTED THE CONTAINMENT WALL AT A GROUND SPEED OF 30 KTS.

The delay from moving to thrust reduction jumped out at me as well. The other issue of running all 4 engines together is another tell-tale. Their own engineers were not following their company's procedure. No chocks; no symmetric runup of 1/4 , 2/3 but not all at once.

What a huge price to pay. Were they rushed? Were they trained? Lots of questions for sure. And I am really, REALLY skeptical about the brave engineer putting plugs in engines under those circumstances. Those plasitic puppies would have been sucked through SO FAST....one can fill in one own's analogies to golf balls and garden hoses

[Steam Driven]

Another picture of the barrier...

[J.O.]

These are not accusations, just some thoughts I've had that may explain how things went so wrong. Given the length of time before an apparent reaction, I'm left wondering if they were all "heads down" before the accident. Also, I suspect that the Airbus people are quite accustomed to doing engine runs many times per week to the point where it's become pretty routine. We all know that complacency sometimes accompanies frequent repetition of a procedure.

[Mitch Cronin]

Now you're clicking a few Bingo's in my noggin JO... Even the number onboard leads my mind to imagine the sorts of things that might have been goin on... These guys are not new to putting out airplanes... the 340 is an old familiar beast to them... 10 occupants, onboard for runs (4 engines, unchocked) on an airplane due really soon to be delivered.... all sounds like a heck of a lot of stuff was being done in that flight deck, all at once... reminds me of a 310 that some poor sod drove into a building in YVR....

[Guest rattler]

One thing that I find interesting is that none of the pictures we have seen yet appear to show any skid marks from the wheels. Shouldn't the full application of the brakes have resulted in skid marks? Another dumb question, is braking on all wheels including the nose or just on the mains?

[boestar]

Speculation Only

Having worked in a production environment and delivering aircraft from the line I can say this.

Functional Test Procedures on an aircraft sometime require tests that are never conducted in the field. One of those tests is ALL Engines at full power. The Brakes should hold the fully laden aircraft from moving.

I do not know what they were doing but I do know that when we were conducting pre delivery testing we did spend alot of time with our heads down while running the engines. Yes could be an accident waiting to happen but collecting the required data required attention away from the outside.

Someone did mention the YVR A310 incident who knows if they were playing with configurations and got out of order and something went wrong.

We may never know the cause for certain but suffice it to say... I am glad I wasnt driving.

B

[Kip Powick]

is braking on all wheels including the nose or just on the mains?

Mains only

[Don Hudson]

rattler;

First, there is no nosewheel braking. Second, there is braking on the mains and the center gear but the center gear is only available through the foot-pedals, not on the park-brake*.

The anti-skid is available on all wheel brakes but is not available below a groundspeed of 10kts unless heavy braking is being demanded. Anti-skid would have been available during the accident sequence and therefore minimum skidding (and tell-tale markings) would be available. Still, if one were on-site, one would definitely see indications of heavy braking if such were applied, they just wouldn't be skid marks.

What I would be interested in seeing is if there were nosewheel scrub marks to indicate an attempt to turn.

The big question has already been asked, and a possible answer posed by JO - why were the thrust levers left at the levels they were until 2 seconds before the wall was hit? And if JO is correct, where were the look-outs both inside and outside the cockpit while the test was being conducted?

The chocking procedure is described on another forum. The wheels are not "chocked" per se but the chocks are placed about a foot in front and behind the wheels. That permits the full weight of the aircraft to rest on the concrete surface, achieving maximum friction between the two surfaces, rather than permitting a wheel to "ride up" the side of the chock leaving the major source of friction with the concrete the chock instead. I think it's been said, but with full power and a light airplane however, is anything going to stop the airplane once it begins to move? "Jumping the chocks" under those circumstances is pretty well stating the obvious - the airplane is going to fairly leap over any impediment given the forces at work.

I wonder if we may never know the full story as this was an "internal" accident and nobody was killed.

*Main and Center gear braking is available as an emergency measure through the park brake control only when the ground spoilers are deployed.

[Moon The Loon]

I do not know what they were doing but I do know that when we were conducting pre delivery testing we did spend alot of time with our heads down while running the engines. Yes could be an accident waiting to happen but collecting the required data required attention away from the outside.

I would suggest then that there are not enough bodies in the flight deck. What is more important during any test than maintaining full control of your bird, so to speak?

In a dedicated test stand, would it not be reasonable to have not chocks but deployable barriers that could rise vertically out of a well in the concrete directly in front of each landing gear bogie? I'm talking Toulouse, not every airport obviously!

Just a miracle nobody was seriously injured or killed. Airbus does build a strong product.

[Guest rattler]

New photo taken from the air. Clearly showing only 1 set of skid marks.

[Moon The Loon]

New photo taken from the air. Clearly showing only 1 set of skid marks.

Bet there were a few more on the flight deck afterwards!

[Kip Powick]

Don,

Based on the photo from Rattler today......can you surmise that the Park Brake may have been "set" but was not "on" for the stbd bogy??

[J.O.]

When the aircraft hit the wall, it shifted to the right significantly (see the picture below). It's actually possible that the skid mark was made by the centre gear. The parking brake does not function on the body gear, just the mains.

[Don Hudson]

Kip;

I think JO is correct here. The skid marks are likely from the center gear.

Reason is, as JO correctly says, the park brake does not pressurize the center gear brakes. The park brake was selected off by the crew 11 or 12 seconds before impact as per the report you posted earlier. That action made braking available to all main and center gears, with anti-skid functioning. I suspect the skid marks are from the center gear and not the nosewheel because the (initial) tracks appear wider apart than the nosewheels, and the chattering feature of the marks indicates that the center gear was lightly loaded relative to the main gears. Perhaps they grow narrower towards the end as a result of the starboard-direction displacement as the aircraft hit and then rode up the wall.

Hope those injured are recovering well. It's a sad sight, still.

[Kip Powick]

OK...understand now.. I thought that the anti-skid was non-operative below a certain speed, and in my mind that was higher than 30 kts, but I see, by rereading the thread, that it is effective down to 10 knots.

I would agree that perhaps the centre gear was cocked off a bit and that would be indicated by the skid marks.

[Don Hudson]

Yeah, something like that - it's the only explanation that is closest to fitting known facts anyway. Hey Kip - I spent some time at the Marana "Boneyard" at Tuscon yesterday...what a sight. Got there too late to go in, (we spent the day "underground" at the Kartchner Caves) but there's an old PanAm 707 lying there...would love to wander through it!

[Kip Powick]

Don...

Here is a link you might enjoy...........

http://www.flickr.com/photos/telstar/tags/boneyard/

I have spent some time wandering around...well actually in a jeep...at Davis Montham AFB looking at the "retired" USAF/USN stuff......frightening when you think of the money tied up in useless machines. There is a field of F-4s ...more than all the aircraft the CF has in its total inventory !!!

You can find some of the pics at Airliner.Net as well as a good aerial shot if you have Google Earth.

[Mitch Cronin]

I still have a bunch of questions... (besides the obvious - what happened - ones)

What engines did it have?

What N1 would be likely with that EPR on those engines?

How'd they shut em down?

Does the wreckage belong to Airbus? What will they do with it?

Does it belong to an insurance company? If so, what will they do with it?

Just curiosity, but can anyone here answer any of that? ...or would I have to go wade through the slop on some other FForum to find anything?

[Don Hudson]

Thanks Kip - gotta get down there. Re the money tied up, I thought of that right away....all that engineering, building and running, now sitting there - wonder how many billions (or even trillions)? Thanks for the links - will look up.

Mitch;

I suspect those questions haven't been settled yet as fault determination hasn't been made, (at least publicly).

There is no easy way to equate N1 with a particular EPR setting. That was one item with the entire TAM accident discussion that was frustrating - the DFDR had EPR but no N1 trace. However, knowing the Trent, I suspect an EPR > 1.25 was above 75% possibly 80%N1. Take that with a grain, though.

No idea how they'd shut them down.

There will be a lot of salvageable parts I would think. I don't know by what process they would be re-certified for use however, and that will be expensive. Guaging if tolerances have been exceeded would be a daunting task alone, as the airframe is dismantled. Scrap aluminum dealers are likely already preparing bids...

[Fido]

The airplane belongs to Airbus until the customer completes their checks and signs the acceptance forms. No way Etihad is taking this one.

[Kip Powick]

Observations from TWA Seniors Club webmaster, who lives in France .

Aircraft on pre delivery final test runs.

2. On board is an Airbus ground Test engineer in command, and another Airbus ground test engineer in the observers seat. We ADAT (formerly Gamco) send AC engineers to do the acceptance. The ADAT engineer is in the captain's seat, but only participating.

3. The aircraft has all four engines run to full power, and the test is finished.

4. Airbus do not put the aircraft on Chocks (not airbus policy).

5. After engine runs, crew get ready to taxi at low power out of the engine run bay area.

6. Run bay area has two semi-circular concrete structures-- the end of the blast fence as you saw in the photo.

7. Airbus ground engineer calls for one more high power run (1.25 EPR) to check an apparent oil leak on No. 4 engine. Aircraft is on parking brakes. When ac on parking brakes, (which is on blue system hydraulics and two accumulators with pressure), parking brakes unlikely to fail - double system.

8. When two engineers looking at gauges, ADAT engineer notices aircraft is moving - despite parking brakes are on.

9. Airbus ground test engineer, tries hard to control ac thru main brakes operating thru the BSCU (Brake and steering control system), and reports he cannot control the aircraft, stop or steer it.

10. In the system if main green system fails (no hydraulic pressure) and BSCU double channel fails, then no brake and steering system, but alternate brakes should kick in, working thru the blue system,-- why does that not work???

11. AC crashes to the front fixed structure and climbs it.

12. There are a total 9 people on board, 4 ADAT engineers in economy zone checking IFE/Avionics, 2 ADAT engineers in the first class zone checking IFE/Avionics, 1 ADAT A and C licensed engineer in the cockpit captain seat participating in the runs and 2 Airbus engineers in the cockpit.

13. The ac breaks in 2 with the three persons trapped in the cockpit, two in the first class and 4 in the economy zone.

14. Cabin possible dead (?).

15. Rescue services and fire department rush to site and rescue all. ADAT engineer breaks his ankle, two other engineers hurt with cuts and bruises, Airbus engineer in the observers seat breaks his leg and hurts his back, and the other Airbus engineer in the cockpit OK.

16. All engineers rushed to hospital, they do not have life-threatening injuries.

17.The investigation in under the lead of the French DGAC authorities, Airbus and the police. Etihad has asked to sit in the investigations.

18. This is one of the Bizarre events, not very common

19. Questions: why did the parking brakes fail, why could they not stop it on the main or alternate system, was the aircraft at too high a speed to control it with just brakes?? This will come under the investigation.

20. Airbus is registered by Airbus, title transfer was supposed to be tomorrow. So technically it is Airbus responsibility and insurance.

Question: Did they not retard throttles or apply reverse thrust???