Five people to face Concorde crash trial

[PJ2]

Captain Airclues;

I suggest that you have another look at your photos. The BA aircraft has FOD Deflectors, the AF aircraft does not.

I believe the photos show in both cases that the deflectors are present - bit difficult to see in the AF photo but they're there.

Regarding the deflectors issue

From the BEA report:

1.6.2.4 Deflectors
The deflectors are situated forward of each main
landing gear. Their function is to deflect projected
water so that it does not enter the engine air
intakes. Weighing around four kilos, they are made
of composite materials and fibre glass (to make
them frangible) except for the bogie fasteners.

In 1995, these deflectors were the subject of an
optional Service Bulletin (SST 32-103 of 12/01/95
modified on 28/02/95) which proposed the insertion
of two cables in the leading edge in order to retain
pieces of the deflectors in case of failure. Air France

did not apply the aforementioned Service Bulletin.

Regarding aircraft weight,

the aircraft weight at which the takeoff was commenced was 185,880 kg, for a MTOW of 185,070 kg. The investigation confirmed these figures and showed that this excess weight had no significant effect on the takeoff and acceleration distances.

and from "Findings:"

Repeating the calculations for the flight preparation showed that the estimated weight of the aircraft on departure was in accordance with operational limits.

Taking into account the fuel not consumed during taxiing, the aircraft’s takeoff weight in fact exceeded the maximum weight by about one ton. Any effect on takeoff performance from this excess weight was negligible.
[/quote] and, regarding the tailwind,

Equally, the controller’s announcement of a

tailwind did not lead to the slightest comment from the crew, which is, as we have seen, surprising.

For a tailwind of 8 kt, the takeoff weight is reduced to 183,300 kilograms due to a tyre speed limitation. 1.17.1.4.2 Extracts of Procedures from Concorde TU Manual Paragraph 10, Wind limit, page II-01.10.4, specifies that the tailwind limit for a takeoff is 20 kt.

Regarding the #2 engine shutdown:

The shutdown of engine 2 before reaching 400 feet resulted from the Captain and Flight Engineer’s analysis of the situation. Indeed, less than three seconds after the failure of

engine 2 was announced by the FE and the controller had informed the crew of the presence of flames at the rear of the aircraft, the engine’s fire alarm (red alarm) and the associated gong sounded. The exceptional environment described above quite naturally led the FE to ask to shut down the engine. This was immediately confirmed by the Captain’s calling for the engine fire procedure. This engine had in fact practically been at idle power for several seconds and the fire alarm was sounding. The engine was therefore shut down following the “engine fire” procedure after having run for twelve seconds at low power. It is important to note that the Concorde Flight Manual requires an immediate reaction by the crew in case of a red alarm.

[sispanys ria]

Casper,
I don't know where you are from, but I cannot tolerate you have this attitude towards France when you obviously haven't read the report !

Read it and then make your comments. The deflectors wouldn't have helped ar all, and it all comes from a design problem which operators never wanted to correct while knowing all the issues. As far as I know, France was not alone to design and operate the bird...

[Xorthis]

The deflectors in question were to prevent water spray being ingested by the engines as stated above.

From what I know about French Law, if an aircraft drops something on the runway which causes an incident, the owners of that aircraft are accountable. Not taking into account the design flaws and the fact that the tyres puncturing the fuel tanks when bursting were known issues, if the FOD was not on that runway that plane would have been put in the situation that resolved into the crash. Right or wrong, that's how the French government see it.

[bsieker]

Water deflectors

I have little tolerance for the ongoing nonsense spread about this tragic accident, and I won't comment on it again. I have analysed the accident in my Diploma Thesis, which is available for download, as is the Official Report. Please read at least the BEA report, and if you're curious, read my analysis, too.

Getting that out of the way: I'd like to clarify some little details about the water deflectors.

• Both Air France and British Airways Concordes are, and have always been, fitted with the water deflectors.
• Their function is to deflect water from contaminated runways away from the engine main and auxiliary air intakes. Demonstrating operation on a flooded runway is a certification test.
• The mentioned optional service bulletin, implemented by BA but not by AF, does not concern the water deflectors themselves, but restraining cables intended to keep the water deflectors from flying away and damaging the airframe in case they are torn off.
• Although the water deflectors of the accident aircraft were torn off, broke, and flew away, they did not contribute to the accident, nor would their absense have made any difference.
• Read the report, it has several photos of the water deflectors, both installed in one piece, and torn off and broken.

Bernd

[Phlap1]

The water deflector detached from the main deflector on the bogie of
the subject aeroplane.
You missed this vital detail in your very detailed thesis.

[DL-EDI]

As this is my first post here, I should be clear from the start that I'm not in the aviation industry - never have been and probably never will be. However, I have been engaged in previous "discussions" on this subject at Another Place so I hope I've learned something from those who are in the industry, particularly those with experience of Concorde operations.

There are a few issues I'd like to comment on:

Runway Inspections
It's my understanding that, prior to this accident, runway inspections were carried out "at regular intervals" and not specifically prior to a Concorde movement. The inspections prior to each Concorde movement were only introduced as a result of the accident.

Spray Deflectors
As someone already stated, these were designed to prevent spray from the main gear entering the engines and were, structurally, pretty "light-weight". Due to concerns from previous incidents, BA chose to reinforce theirs with a steel cable but I believe this was to prevent broken pieces of the deflector from causing too much damage.

"Punctured" Fuel Tank
Again from my understanding, this was not a tyre burst like any that had happened before, to any type. In this case, the titanium "blade" caused the tyre to rupture in such a way that a 2 metre slab hit the underside of the wing at high speed, causing internal shock waves to rupture the tank from within.

Tyre Bursts
I've seen it stated many times elsewhere that "any other type" would not have batted an eyelid in the same circumstances but I've yet to see any authoritative evidence. Is there any evidence of what happens when any other type runs over a titanium "blade" at high speed? On the other hand, there have been fatal accidents and serious incidents following tyre bursts on other types.

I'm just not sure that this type of incident could reasonably have been predicted from the experiences of the previous incidents, where much smaller pieces of debris caused much less damage. It's also my understanding that the earlier type of incidents had ceased in the latter years (~20?) of its service.

Now, I'm adopting the "Brace" position in case anyone feels like ripping my comments to shreds. I'll remind you all again that I am not pretending to have any authority on these matters whatsoever. As a Concorde fan, I simply feel the need to speak in its defence from time to time.

[Magplug]

PJ2.... Your narrative is incorrect.

The FE shut down an engine on the runway prior to V1 without any reference to anybody else on the flight deck (read the CVR transcript). There is no 2/3 crew SOP in the world that has one guy shutting down engines below a safe height let alone unmonitored. As the other engine subsequently failed before the gear could be raised their fate was sealed....Unable to accelerate to V2 and all the drag of the gear hanging in the breeze.

Had the FE not embarked on that Maverick course of action there should have been enough Hyd pressure from the two lame engines to raise the gear and fly away. When the fuel cells were empty the spectacular fuel fire would have ceased, with some good flying they may just have saved the day. Being two tonnes over max tyre speed did not help, neither did ignoring eight knots of tailwind.

AF ploughed in an A320 F-GGED a VOR on approach to Stasbourg in 1992 because the pilots did not know the difference between FPA 3.3 and VS 3300fpm... despite having the rather large clue that the a/c would not slow below 280kts. Ultimately they ploughed in a serviceable a/c well short of the field killing 87 people. The did not have GPWS. It was not considered that French pilots required that protection.

So when people talk of arrogance I don't believe they are far wide of the mark, particularly when you consider that since Concorde AF have lost another 2 airframes - Both with Human Factors as the primary cause

AF358 F-GLZQ A340 at YYZ 2-Aug-2005 ...Attempted landing it thunderstorm
AF7775 F100 PUF-CDG 25-Jan-2007 ....Failure to de-ice before departure

[Capt Fathom]

French arrogance has no limits

Yep!

And they are suing everyone over the Toronto overrun accident.

'It wasn't our fault' !!!

[Mel Effluent]

The decision to prosecute has much more far-reaching implications with a cumulatively negative impact on flight safety. Article 3.1 of ICAO Annex 13 states that:

The sole objective of the investigation of an accident or incident shall be the prevention of accidents and incidents. It is not the purpose of this activity to apportion blame or liability.

What are the chances of conducting an effective investigation into an aircraft accident if there is a risk of witnesses being prosecuted if they tell the truth?

[bsieker]

Some Facts.

Originally Posted by Magplug

PJ2.... Your narrative is incorrect.

Well, so is yours. Actually having read the report and its appendices helps.

The FE shut down an engine on the runway prior to V1 without any reference to anybody else on the flight deck (read the CVR transcript). There is no 2/3 crew SOP in the world that has one guy shutting down engines below a safe height let alone unmonitored. As the other engine subsequently failed before the gear could be raised their fate was sealed....Unable to accelerate to V2 and all the drag of the gear hanging in the breeze.

The engine shutdown was past v1.

Please read the CVR transcript:

Originally Posted by CVR Transcript, English translation

14:43:03.7 - F/O: "V1"
14:43:10.1 - Noise
[...]
14:43:13.0 - F/O: "Watch Out!"
14:43:13.4 - VHF: "Concorde, [...] you have flames behind you"
[...]
14:43:20.4 - F/E: "Failure engine 2"
[...]
14:43:22.8 - Engine Fire Alarm
[...]
14:43:24.8 - F/E: "Shutdown Engine 2"
14:43:25.8 - CPT: Engine Fire Procedure"

Please read my analysis, made after consultation with Concorde's Chief aerodynamicist, Clive Leyman. It shows that, regardless of the appropriateness of the F/E's shutting down engine no. 2, it would not have worked anyway as long as the fire was burning, because it was ingesting kerosene and/or flames. Even engine no. 1, farther away from the flames, did not reach its full power.

Even so, only one second after the Flight Engineer announced that he was going to shut down engine no. 2, the Captain ordered the engine fire procedure, which includes shutting down the engine. Presumably, the F/E took more than one second to announce his intentions, so it coincided with the Captain's orders.

Had the FE not embarked on that Maverick course of action there should have been enough Hyd pressure from the two lame engines to raise the gear and fly away.

1/ Engines 1 and 2 provide Green hydraulic pressure, which is the only hydraylic system available for gear retraction.

2/ Engine 1 was anything but lame. It was running, after a brief loss of power, at normal takeoff power, although, unlike engines 3 and 4, it did not quite reach the demanded contingency power.

2/ The gear could not be raised because tyre pieces had damaged a door, preventing door movement and thus a necessary signal for unlocking and movement of the landing gear proper.

When the fuel cells were empty the spectacular fuel fire would have ceased, with some good flying they may just have saved the day. Being two tonnes over max tyre speed did not help, neither did ignoring eight knots of tailwind.

1/ Those canisters in the aircraft that hold fuel are called "fuel tanks". a "Fuel Cell" is a hydrogen/oxygen-fueled cell that provides electric power. Concorde has no fuel cells.

2/ Assuming a constant fuel flow rate, the fire would have continued burning for at least another 2 minutes. As the fire prevented the left hand side engines from working normally, nothing could have been gained. In practice, fuel flow from the leak would reduce when the tank was becoming near empty. It is even conceivable that a nearly-empty tank might contain an explosive fuel-air-mixture and explode. Waiting for the tank to empty was not an option.

3/ The wing was starting to deform from the intense heat of the fire, accelerating loss of control.

4/ There are indications that the flight crew was well aware of a slight overweight/tail wind condition, leading to tyre stress very close to, or possibly slightly exceeding the rolling limit. Apparently they attempted, regardless of the approaching runway edge, a somewhat early, but slow, rotation.

The reason for the extraordinary tyre stress on Concorde aircraft is the combination of a very high Vr/V2 speeds, and practically zero lift prior to rotation. Rotation-initiation produces a small amount of negative lift for a brief time, so an early and slow rotation can alleviate tyre stress on Concorde takeoffs. Conventional aircraft already produce significant lift during takeoff roll before rotation.

AF ploughed in an A320 F-GGED [...]

What has this got to do with Concorde? Oh, you're trying to "prove" that all Air France cockpit crews are incompetent. Nice try.


Bernd

[NVpilot]

Bernd, you are obviously well informed, what is your opinion of why their takeoff roll was headed toward the edge of the runway to begin with, and is it possible that had they stayed near the centerline of the runway, they would have never hit any FOD?

Thank you in advance.

[Xeque]

NVPilot
The report states that the drift towards the left of centreline began after the tyre had been damaged.
Basically the report says (as far as my reading of it is concerned) that everything up to the point when they ran over the piece of metal (start up, taxi, line up and launch) was, in all respects, normal. That includes the CofG, the take-off weight and the tailwind component. Frankly, my understanding of the report is that the crew did nothing wrong and that it all went pear shaped after hitting the metal strip on the runway just before VR. Thereafter their fate was pretty much sealed.
Much has been made of the missing spacer on the undercarriage bogie but, again, the report categorically states that its absence had nothing to do with the accident.

[lomapaseo]

and is it possible that had they stayed near the centerline of the runway, they would have never hit any FOD?

I've walked a few runways both reactively as well as proactively.

Immediately following an incident the debris is distributed mostly along the flight path with about a 15 deg side to side dispersal.

Several days later the debris has migrated to the very edges within a foot or so of the grass overhang.

So yes the runways are cleaner along the center, but you can build a plane from the parts near the edges.

This part of the discussion is statistical at most and I am not sure of it's application to the courts.

[bsieker]

NVpilot,

Xeque's post pretty much sums it up, thanks a lot. If you don't believe it, take a look at the FDR data yourself, they're available as Appendix 4 to the official report. No rudder inputs out of the ordinary are recorded, up to the point where they hit the titanium strip. Centre line tracking and acceleration was normal.

The missing spacer may have slightly exacerbated the bogie movement after the tyre burst, but certainly not before. Even then its influence above and beyond the asymmetric forces caused by the burst tyre itself and asymmetric thrust would have been negligible.

Not specifically to NVpilot: when engaging in tirades against alleged French arrogance, please keep in mind that the AAIB was also involved in the investigation. Although they did contest some points, and complained about being hindered by the French judicial inquiries (separate from the BEA investigation!), they did not argue with the non-effect of the spacer.


Bernd

[Robert Campbell]

FOD Deflectors

Look at the photos again. There are FOD deflectors on both aircraft

[PJ2]

Magplug;

The FE shut down an engine on the runway prior to V1 without any reference to anybody else on the flight deck (read the CVR transcript).

Nonsense. How could an engine be shut down "prior to V1" when the aircraft had not yet struck the debris on the runway and the engine had not yet been affected? It is you who needs to reference the Report, not I.

The report states:

At 14 h 42 min 31 s, the PF commenced takeoff. At 14 h 42 min 54.6 s, the PNF called
one hundred knots, then V1 nine seconds later.
A few seconds after that, tyre No 2 (right front) on the left main landing gear was
destroyed after having run over a piece of metal lost by an aircraft that had taken off five
minutes before. The destruction of the tyre in all probability resulted in large pieces of
rubber being thrown against the underside of the left wing and the rupture of a part of
tank 5. A severe fire broke out under the left wing and around the same time engines 1
and 2 suffered a loss of thrust, severe for engine 2, slight for engine 1.

The clearly anti-French agenda in your and others' posts is offensive to good flight safety work. As Bernd has observed, the AAIB participated in the Report. You may desire to hold and even broadcast such thoughts, but if you wish to establish and retain credibility insofar as a safety discussion goes (what, not who), a separation of personal vs. professional commentary is required.

[pontifex]

DL-EDI has hit the nail on the head when he says that the piece of tyre did NOT puncture the fuel tank and that it was an internal shock wave reflected from the upper surface of the tank that caused it to burst open. This eventuality had been anticipated by the manufacturer so that the clearance to service required that there should be an air gap between fuel and structure in this tank on take off, and this was incorporated in SOPs. Because the crash aircraft had elected to go for a short taxi (hence downwind T/O), this air gap did not exist because anticipated fuel had not been used. Just one link in the chain! But an important one that might constitute an intentional breach of SOPs.

[DL-EDI]

Pontifex:

Just for the record, that's a shade more than I was suggesting.

I wasn't aware of this aspect of the SOP and have no idea whether or not it was breached.

[Dysag]

PJ2

The "anti-French agenda" arises because the French will do anything to protect their national champions. In this case Air France.

It's not a secret that in France the truth will always be sacrificed to preserve the good reputation of AFR, Airbus, etc. The French public think that's normal, so why deny it?

[atakacs]

This eventuality had been anticipated by the manufacturer so that the clearance to service required that there should be an air gap between fuel and structure in this tank on take off, and this was incorporated in SOPs

Was that after the relatively similar incident in Washington in 1979 ?

Regarding early rotation I'm wondering if the pilot wanted to make sure to miss the 747 waiting on the left side of the runaway (in which french president Chirac was returning from a trip in Japan) ?