Pierre Heijboer met zijn boek Doemvlucht: De verzwegen geheimen van de Bijlmerramp

(17-06) De standpunten van de Israëlische leden van de onderzoeks-

commissie naar de ramp, in november 1992 vastgelegd in een rapport.

(17-06) Correctie.

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Op bladzijde 135, de voorlaatste alinea, staat de zin: 'De raad had nog de mogelijk om hier en daar iets te corrigeren.'

Dit moet zijn: 'De raad had nog de mogelijkheid om hier en daar iets te corrigeren.'

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                                                                                       CONFIDENTIAL

                                                                    EL AL Aircraft Accident 747-200F 4X-AXG

                                                                                         747-200F 4X-AXG

                                                                         Flight Ly1862, Amsterdam, October 4,



Important Notes

a.        From the viewpoint of this Committee the report is final. However, readers af the report must take into account that

       the investigation af certain engineering items and others has not been exhausted, and may continue for additional weeks

       or months in laboratories in the USA, in Holland and in Israel. The Committee does not believe that the findings af

       those investigations will change the contents af the report or its recommendations, other than to amplify them.

b.       This report represents solely the opinion of the Chairman and members of the Committee. It does not purport to

        represent the opinion of the Dutch Enquiry Committee, not the opinion of the Committee appointed by the Israeli

        Ministry of Transport.

Hebrew version signed in Hebrew

Amir Chairman

Capt. A.Oz Memher D.Finkelstein Memher T.Livneh Memher

November 1992



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6 Conclusions

6.1. Main Conclusions

6.1.1. The source of the fault was in a break which occurred in the No.3 Engine mount attachment to the wing. The break

         began most likely in the right hand fuse pin and from there the fault developed leading to the complete separation of

          the mount  from the wing.

6.1.2. There were no problems with engine #3 and 4

6.1.3. The extensive damage inf1icted on the right wing rendered the control extremely difficu1t, possib1y resu1ting in an

           inevitable tota1 loss of control.

6.1.4. The flight crew struggled with all its might and ability to stabilize the aircraft and to bring it to a landing. However, in

          the end it found itself in a situation from which there was no escape.

6.1.5. With hindsight one may speculate that an enlarged first circuit, choosing a different runway (apparently 06),

          might have afforded better conditions to bring the aircraft to the beginning of. the final approach for a landing.

         In this connection one should bear in mind that the crew was handling a heavy aircraft, with an incessant fire warning

         of engine #3 in sight that commanded the earliest possible landing while maintaining high speed for as long as

        possible.

          The Committee of Inquiry is of the opinion that even had the crew succeeded in landing at a very high speed with

        very  partial control, it would have resulted in a crash landing on the runway, next to or beyond it.

6.1.6. The final loss of control resulted from control surface insufficiency during the last 40 seconds (approx.) of the flight.

          It appears that the right wing suffered a loss of lift, resulting in an imbalance of the moments in the rolling plane. This

          brought about a drop of the right wing, accompanied by a yaw to the right, which developed into a spiral turn, from

          which the aircraft did not recover.

                                                                                                  -40 -                                                                      Rev. 21.1.93

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The possible reasons tor this critical condition could have been:

           1) The tearing away of surfaces and destruction on the wing;

           2) Loss of aerodynamic efficiency of the right inboard aileron;

           3) A stall of a part of the wing;

           4) every possible combination of the above.

6.1.7. In connection with the accident or its cause, the Committee found no fault in the technical

           servicing of the aircraft such as: compliance with manufacturers instructions, FAA instructions,

           observance of the inspection routines on the aircraft, recording of squawks and their rectification,

           or any lack of followup on the technical condition of the aircraft, its engines and its systems.

6.1.8.   The Committee found na noteworthy discrepancies concerning the planning of the flight, its

           preparation, cargo loading ar any other services connected with its execution.

6.1.9    To the best of its knowledge and judgment the Committee finds that the sole responsibility for

           the accident rests with the aircraft manufacturer.

6.1.10. The fact that a fuse pin breakage caused the separation of an engine and a major accident, is in

            itself a deviation from the .'fail-safe-design" principle. It is a surprise, that this principle, which

           was introduced in the regulations of the FAA in the year 1976, was not applied, and to this day

           is not applied to 747 aircraft.

6.1.11. The Committee is of the opinion that in the case of the 747F accident of China Airlines last year,

            an accident which bears a strong resamblance to the El Al accident, the manufacturer's reaction has

           been slow and irresolute to the extent that borders on negligence.

6.2.          Complementarv Conclusions reqardinq the Aviation Aspect

6.2.1.   The false fire warning and the high aircraft gross weight led ta the choice of runway 27 for landing.

6.2.2. Air Traffic Control gave insufficient support to an aircraft that had reported an emergency thereby

           contributing to the difficulties of manoeuvering the aircraft towards landing.





                                                                      41                                                                       Rev. 21.1.93

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6.2.3 .The Committee is convinced that in the case of this accident, which was caused by a

          technical failure, the aircraft was in a condition where its operation in accordance with any

         emergency procedures learned and practiced by El Al crews could not have prevented loss

         of control and the crash of the aircraft.

6.3.        Complementary Conclusions Regarding the Technical Aspect

             6.3.1. The aircraft crash was caused by the separation of the two right engines that was initiated

                       by the failure of the attachment of #3 engine mounting to the right wing. This mounting is

                       attached to the wing by 4 fittings, containing fuse pins. The fuse pins must withstand all

                       possible loads during flight. Two main (midspar} fittings of the four are mounted on the

                       center wing spar. The fuse pin of the right fitting was found sheared in two planes due

                        fatigue failure (Appendices 24, 25}.

                       As a result mounting #3 suddenly sagged, fractured the lef t midspar fitting which led to

                       instantaneous separaticn and further damage to the wing. The separated mounting remained

                       attached to the engine.

             6.3.2 The suspension system to the wings is rnaintained in accordance with standard rnaintenance

                       procedures. Since 1979, the suspension system to the wings was the subject of nine

                       additional airworthiness directives. The Investigation Committee found that all requirements

                       and airworthiness directives were adequately covered by El Al Engineering directives, and

                       were fully cornplied with by the technical bodies concerned and within the prescribed time

                       limits. No discrepancies, deviations or omissions were found in this respect. The table

                        (Appendix 26} itemizes all pertinent instructions.

            6.3.3. Af ter the accident the El Al non-destructive testing department was visited by a delegation

                      of senior Boeing personnel, in order to determine the reliability of the testing of the pins.

                      The delegation found no fault with the competence of the technicians, with the reliabillty of

                       the equipment or with the procedures and the methods applied.

                                                                                 42

(17-06)     Interrim-rapport van de Israëlische luchtvaart-autoriteiten over de

ramp in de Bijlmermeer, gedateerd 9 februari 1993.

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Section E -Summar Conclusions and Recommendations

Foreword to the Summarv

This report, as noted in the introduction, is an interim report. The investigation is still incomplete and final conclusions should not be reached nor the events summarized. Neither should the steps which must be taken concluded as yet.

Despite the above, we intend to determine, while observing the utmost caution, those facts and conclusions which we believe will not change as the inquiry progresses. Considering that the aircraft continue to carry passengers and freight, there is a certain urgency in taking such steps which may increase flight safety and ensure that accidents of this kind do not happen again. The following should be viewed in this light.

The Causes of the Accident

The direct cause of the accident was the failure of no.3 engine's strut and the damages caused as a result. The chain of technical events up to the aircraft's crash included:

a. Failure of the no.3 engine strut .

b. Break away of engine no.

c. Collision between engine no.3 and engine no.4 and the break away of engine no.4.

d. Hydraulic, pneumatic, electrical, the right side ceased tc functicn and fuel systems on

e. Right wing controls and lifting surfaces were damaged as a result of the engines

   breaking off. Possibly, additional damage was caused later which resulted in loss of

   control of the aircraft.

The final crash of the aircraft was a result of loss of control on the way to landing, when the aircraft was at 1700 feet and at a speed of 280 knots.

The separation of engine no.3 from the wing was caused by the shearing of the balt attaching the strut ta the aircraft. Part of the severed bolt was found at the crash site in the bolt hole, attached to the wing spar.

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                                                                                  -23-

The exact chain of failure and the manner in which the other fittings ataching the strut broke, are still not clear. Some of these pars are in laboratory examination at the time of this writing.

On principle, The strut structure should be fail safe" - i.e. the fal1ure of one element should not cause the strut to break away from the wing. The remaining connections should continue to bear the stresses of flight. The sudden and total failure of the strut system is astounding and demands thorough examination by the aircraft's manufacturer.

In l.ight of the above the committee's opinion is that the aircraft failed to meet the present legal requirements for withstanding fatigue and damage tolerance as defined and detailed in FAA AC25-571-1A-

Summary of In Flight Operation

The aircraft.s crew was faced with an extremely severe emergency as a result of the engines breaking away and the chain of failures which accompanied this, and acted to the best of their ability to bring the aircraft back to land as soon as possible.

The captain.s decision to land on the closest runway (27) despite the fact that this was not the runway in use. was a considered decision acceptable under the circumstances, even though there are considerations to prefer some other decision.

The dialogue between the aircraft and the tower (there is no additional information on cockpit talk, because of the 1oss of the cockpit voice recorder (CVR}} shows that the actions of the crew were calm and professional.

When the aircraft's crew declared an emergency the tower cleared the airport's air space of traffic gave the aircraft priority and freedom of choice for the crew provided information and control for the aircraft's approach to landing.

Amore detailed professional examination of the tower's work requires further analysis and is some what related to an analysis of the captain's considerations in the choice of runway.

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                                                                           -24-

4 Aircraft Maintenance

Inspection of the aircraft's maintenance documents, including inspections of the bolts, did not bring forth any exceptional findings. It seems that the company followed instructions for the inspection of the bolts as directed by the PAA and Boeing, to the letter.

The Problem of the Bolts

The problem of the bolts on 747 aircraft has been weIl known for some time. The instructions for their inspection and handling have been updated and amended from time to time. These actions have not brought about the desired results and did not prevent this last accident. Even if some defect in the application and execution of the instructions is found as the inquiry continues, this will not remove the concern that something is wrong with the strut's planning or production or maintenance process.

5 Recording and Indication Systems

Some of the recording and indication systems which are Intended to operate In failures and emergencies, failed completely or partially in the circumstances of this accident. For example:

A     The recording cassette of the flight data recorder did not survive to the extent that would allow deciphering

       of the flight's last critical moments.

b.     The cockpit voice recorder (CVR) was lost and probably Incinerated at the crash site.

C      The fire warning system of engine no.3 operated and warned of a fire in that engine after the engine was no

        Ionger attached to the aircraft.

The above should cause same thought and initiative ta improve the situation. Some ideas along these lines will be submitted by this committee at a later date.

6 Simulator checks and training

Exact analysis of in flight operation, flight data and the actions of the crew was impossible without the cockpit voice recorder and FDR data for the last few minutes of the flight. In order to investigate more thoroughly and complete the picture, it is most vital that some possible scenarios should be examined in a simulator. A decision to this effect was taken by the lntegrated committee of inquiry. It is most important that this be done soon, with the participation of a representative of the Israeli comittee.

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                                                                                    -25-

The simulated flights should also be used to develop flight exercises which will enable the training of air crews to contend wlth emergencies such as those of this accident and other sltuations, as determined by the company and lts senior pilots.

7 Inspection and Handling of the Bolts

In view of the criticality of the status of each and every bolt in the strut assembly, we recommend that EL AL take the following actions:

a. Perform without delay the inspection process set out by the FAA and Boeing.

b. Systematically replace all the bolts on.747 aircraft, except for those installed within the last six months, and

   do this in the shortest time made possible by supply of the bolts from the manufacturer. This

   recommendation should be performed with priority to engines 2 and 3 (inboard).

8 Summary

This report reflects the situation as known at the time of its writing. In further investigation, the committee will focus on the fbllowing activities:

a.. Continue the effort to decipher additional segments of the PDR.

b. Laboratory inspection of aircraft debris and critical parts.

c. Examination of possible scenarios in a simulator.

d. Engineering investigation of the engine strut structure.

e. Summaries of accumulated information and more thorough understanding of the processes which caused the

   accident.

We will continue to coöperate with the Dutch committee of inquiry with the intent of completing the most thorough investigation possible, drawing conclusions and submitting recommendations which will contribute to safe flight in the future.