Photo: N823GA Ground Track, from BEA Report, figure 2.

Eddie Sez:

The Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile (BEA) did a very nice bit of investigative work on this mishap with one exception: the conclusion wasn't forceful enough. Before I explain, let me dive into the very nature of aircraft mishap investigation.

In theory, the primary motivation for investigating an aircraft crash is prevention. You don't want it to happen again. When I went to the Air Force Mishap Investigation Course and later to the Chief of Safety Course, we were told that our standard of proof was different than what the Judge Advocates General would use. They had to prove something beyond any reasonable doubt. In the safety business we don't have that restriction. Nobody was going to jail as a result of our findings, but somebody could be spared a future mishap. This report dances around the obvious because they don't have proof beyond all reasonable doubt.

My goal here is prevention. We can learn a few things from this mishap that can save lives. So let's do that. If I were writing this mishap report my findings, my personal opinions, would read as follows:

  1. The captain was a product of a long airline career flying with a major airline in sterile conditions where every operation was thoroughly pretested and validated to ensure it could be flown by the company's weakest pilots.

  2. The FAA failed to ensure the training vendor was doing its job when awarding type certificates.

  3. The training vendor failed to properly train the captain to operate as a pilot monitoring (PM) from the left seat and failed to fully cover known emergency procedures required in the aircraft's history.

  4. The operator failed to consider the captain's lack of experience in type and with corporate aviation.

  5. The operator and training vendor failed to enforce adequate checklist discipline.

  6. The operator failed to consider the lack of experience of the pilot pairing when scheduling them for a short depositioning flight into a short runway.

  7. The captain had a track record of forgetting to arm the aircraft automatic ground spoiler system and was known to manipulate the controls (including the nose wheel steering) while flying as the PM.

  8. The pilot flying (PF) who was the Second-in-Command (SIC), failed to properly fly the airplane onto the runway, allowing it to float after main gear touchdown which allowed the thrust reverser system to arm but then disarm as the weight on wheels system switched from air to ground, to air again, before finally returning to the ground mode.

  9. The captain apparently had his hand on the nosewheel tiller and commanded a strong left turn to the nosewheel steering system. Once the nosewheel touched down, the aircraft started to veer strongly left.

  10. The captain was unaware of the proper procedure in this airplane to disarm the nosewheel steering system after such a deviation from a forward track.

Those are pretty harsh, I agree. But I hope it instills the following thoughts:

  1. You cannot hire highly experienced pilots thinking high total time and many years with one type of operation will translate to other operations. This captain was not suited for the responsibility as captain in a GIV or as a PM flying onto a short runway.

  2. A training vendor that is nothing more than a type rating mill is a recipe for bad things to happen. The vendor failed to teach the emergency procedure in question or the techniques needed to fly as a PM from the left seat.

  3. Checklist discipline is a life saver. Had the ground spoilers been armed the touchdown could have been more deliberate and much of the confusion that followed would have been avoided.

  4. You must fly the airplane onto the runway in an expeditious manner. An airplane is most vulnerable in the flare and any effort made to "grease" the touchdown can have other, unintended, consequences.

What follows are quotes from the sources listed below, as well as my comments in blue.


Accident Report


Narrative

[BEA Report, pg. 8] During a visual approach to land on runway 13 at Le Castellet aerodrome, the crew omitted to arm the ground spoilers. During touchdown, the latter did not deploy. The crew applied a nose-down input which resulted, for a short period of less than one second, in unusually heavy loading of the nose gear. The aeroplane exited the runway to the left, hit some trees and caught fire.

The runway excursion was the result of an orientation to the left of the nose gear and the inability of the crew to recover from a situation for which it had not been trained. The investigation revealed inadequate pre-flight preparation, checklists that were not carried out fully and in an appropriate manner.

[BEA Report, ¶1.1]


Analysis

Figure: GIV Nose Gear Steering Control System, from BEA Report, figure 5.

[BEA Report, ¶1.6.5]

[BEA Report, ¶1.7] At the time of the landing at 13 h 18, the maximum spot wind over a minute was 10 kt from 300°. (Basically all crosswind.)

[BEA Report, ¶1.11.1] The examination of the site and the wreckage showed:

Figure: GIV Nose Gear Striation Values, from BEA Report, figure 14.

[BEA Report, ¶1.12.2] The first tyre marks observed on the runway attributed to N823GA were left by the nose gear. They were continuous to the runway edge over a longitudinal distance (in relation to the runway centre line) of 270 metres. Shortly before the runway centre line and until the runway edge these marks had striations trending towards the right in the direction of travel of the aeroplane. Their angle, measured between the edge of the mark and the striation, changed along the marks.

If the nose gear is deflected to the left while the airplane is still headed mostly straight, the rubber tends to rub off to the right, the so-called striation marks.

[BEA Report, ¶1.16.7]

  • Examination of the tyre marks left by N823GA on the runway revealed the presence of rectilinear striations oriented to the right, in the direction of movement of the aeroplane.

  • The study includes tests that show that, for an unbraked wheel, the striations are substantially oriented at 90° in relation to the plane of the wheel (parallel to its rotation axis). Their orientation is close to the direction of movement of the wheel if it is partially braked.

  • This study shows that between the time of the second nose landing gear touchdown and the time of the runway excursion, the nose gear was strongly oriented to the left, generating marked marks and rectilinear striations.

[BEA Report, ¶1.16.4] In order to study the dynamics of the aeroplane on the runway and the various possibilities that might explain the lateral deviation to the left and the runway excursion, Gulfstream, the NTSB and BEA independently carried out several simulations of the aeroplane’s trajectory.

  • The simulations carried out by Gulfstream failed to reproduce the trajectory of N823GA.

  • The NTSB used TruckSim software to simulate and analyse the dynamic behaviour of heavy vehicles in contact with the ground. . . . The results obtained show that only an orientation to the left of the nose landing gear wheels could reproduce the N823GA’s trajectory.

  • The BEA completed the model used for the calculation of vertical loads on the landing gear . . . only an orientation to the left of the wheels of the nose landing gear was capable of reproducing the N823GA’s trajectory using the vertical loads calculated.

[BEA Report, ¶1.17.5.5]

[BEA Report, ¶1.11.2] The [Cockpit Voice] recording started during taxiing in Nice. This made it possible to determine, during the flight:

[BEA Report, ¶3.1]

[BEA Report, ¶1.5] The Captain was employed by American Airlines between 1977 and 2008. He had been flying as Captain on Boeing B777s since 2003. After retiring from American Airlines, he was hired as a pilot on a part-time basis by UJT on 25 September 2010. He followed the UJT operator’s conversion training (lasting three days between 25 and 29 October 2010) and then passed the type rating course for the Gulfstream G-IV within the CAE Simuflite training organization based in Dallas (Texas) in November 2010.

[BEA Report, ¶1.18.2] Several UJT pilots who flew with the Captain said he was not accustomed to short flights. They also agreed in stating that he was not comfortable with handling the FMS, carrying out checklists and in his role as PM in general. He had a strong personality and sometimes imposed his decisions. Two copilots who flew with him reported that he had already forgotten to arm the ground spoilers. One of them said that during a landing, the Captain, although PM during the flight, had pushed the controls during the landing roll so that "the directional control was more effective".


Probable Cause

[BEA Report, ¶3.2] Forgetting to arm the ground spoilers delayed the deployment of the thrust reversers despite their selection. Several MASTER WARNING alarms were triggered and the deceleration was low. The crew then responded by applying a strong nose-down input in order to make sure that the aeroplane stayed in contact with the ground, resulting in unusually high load for a brief moment on the nose gear. After that, the nose gear wheels deviated to the left as a result of a left input on the tiller or a failure in the steering system. It was not possible to establish a formal link between the high load on the nose gear and this possible failure. The crew was then unable to avoid the runway excursion at high speed and the collision with trees.

[BEA Report, ¶3.2] The accident was caused by the combination of the following factors:


References

Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile (BEA) Accident Report on 13 July 2012 at Le Castellet aerodrome (83) to the Gulfstream G-IV aeroplane registered N823GA, Published October 2015

NTSB Preliminary Information, DCA12RA110, Gulfstream G-IV, N823GA, Le Castellet Airport, France, 13 July 2012