Flight 1862 History - Case Study Example

Flight 1862 Report Flight history On October 4, 1992, a Boeing 747-258F, plane with registration 4X-AXG, traveled from New York to Tel Aviv and a stopover was at Schiphol. During the flight period from New York to Schiphol, three important key issues were noted: irregularities in the voltage of engine, irregularities in the autopilot speed regulation and problems with the shortwave radio. At 2:31 pm local time, the jet landed at schipol and cargo was loaded into the plane; custom authorities gave their approval of these cargos, but it was later discovered that they had not been physically inspected. The aircraft was refueled and some repairs carried out on the irregularities mentioned earlier on, at least provisionally. The Captain Yitzhak Fuchs, First Officer Arnon Ohad, and Flight Engineer Gedalya Sofer were on board. Anat Solomon, who happened to be the only passenger on board, was an employee of E1 A1 traveling to Tel Aviv to be married to a colleague. (El Al Flight 1862 retrieved from http://en.wikipedia.org/wiki/El_Al_Flight_1862) The Departure from Schiphol Flight 1862 was originally scheduled to depart at 5:30 PM, but the departure was delayed till 6:20 PM. At 6:22 PM, Flight 1862 took its departed from runway 01L on a northerly heading. Immediately it went away from the runway, it turned to the right so as to follow the Pampus departure route, with the help of the Pampus VOR/DME navigation station. Soon after the turn, at 6:27 pm, just above the Gooimeer, a lake somewhere near Amsterdam, a very sharp bang was heard above while Flight 1862 was climbing through 6500 feet. Engine 3 was separated from the right wing of the aircraft, and thereby damaging the wing flaps, and struck engine 4 in the process, and this separated it from the wing. The two engines fell off from the plane, attracting the attention of some pleasure boaters who had been taken aback by the loud noise. The Netherlands Coast Guard was immediately notified by the boaters of two strange objects they had seen falling from the sky. A mayday call was made by Captain Fuchs to the control tower and made indications that he wanted to return to Schiphol. At exactly 6:28:45 PM, the captain reported that they had lost the number 3 and number 4 engine, number 3 and number 4 engine. Personnel information The flight crew included the captain, the first officer, and the flight engineer. A review of the qualifications and background of the flight crew revealed that the captain was 59 years old, held an Israeli airline transport license. The flight captain had 25,000 hours total flying time, and 9,500 hours flying the B-747. The first officer, age 32, held an Israeli ATPL with type ratings in the Boeing 747 and Boeing 707. He had 4,288 hours flying time, with 612 hours in the Boeing 747. The flight engineer, aged 61, held an Israeli flight engineer license, with ratings for the Boeing 747 and Boeing 707. He had 26,000 hours total flying time, and 15,000 hours in the B-747. (Flight safety foundation accident prevention 1996) The Route of the fatal flight The enormity of the situation was not yet grasps by ATC. In aviation world, the word "lost" as used by Captain Fuchs generally refers to a loss of engine capacity. As a result of this, ATC therefore believed that the two engines had merely stopped functioning, and did not realize that they had actually fallen off. Probable the crew too did not realize that the engines had fallen off the aircraft. The visibility of the outboard engine on the wing of a 747 from the cockpit is quite difficulty, while the inboard engine on the wing is not visible at all. It is most likely that the crew did not know that both engines had broken away from the right wing. The Emergency landing attempt The runway available for traffic at Schiphol was runway 06 (the Kaagbaan) on the evening of October 4, 1992, that notwithstanding, Captain Fuchs requested for runway 27 (the Buitenveldertbaan) for an emergency landing. Because the wind happens to be from the northeast that evening, the fully loaded plane would have needed to land with considerable tailwind. The damaged aircraft made a circular navigation above Amsterdam In order to first dump fuel so as to remove the plane's excess weight, and then to make a careful and calculated approach to the runway. During this circle, the captain gave an order to the first officer to extend the wing flaps. The flaps extended on the left wing, but as a result of the falling engines that has severely damaged the leading edge of the right wing, the extension of the right wing flaps was not possible. As a result of this, the left wing experienced more lift than the right. Captain Fuchs, as a result of not having a good view of the outside as to what happened to the right wing, informed ATC of a problem with the flaps. Schiphol emergency fire services were immediately positioned along runway 27 in order to extinguish any fires that may erupt upon landing. At first, the aircraft was under control during its descent to the runway, but as it descended and got below 1500 feet and reduced speed, it moved sharply to the right and became uncontrollable. At 6:35:25 PM, a radioed call came to ATC by the first officer "Going down, 1862, going down, going down, copied, going down." In the background, the captain instructed the first officer in Hebrew to raise the flaps and lower the landing gear. The Crash At 6:35 pm local time, the Boeing 747, plowed into two high-rise apartment complexes in the Bijlmermeer neighborhood, in nearly a ninety-degree bank with its right wing pointing at the ground, The building exploded into balls of flames and there was a partial inwards collapsing, and dozens of apartments were destroyed. The cockpit came to rest east of the flats; the debris of the plane was transported to Schiphol for analysis purpose. The parts were no longer used to reconstruct the aircraft. Possible Causes of the crash The design and certification of the B747 pylon was found to be inadequate to provide the required level of safety. Furthermore the system to ensure structural integrity by inspection failed, probably initiated by fatigue in the inboard midspar fuse-pin. This might have been the reason that the no.3 pylon and engine disintegrated from the wing in such a way that the no.4 pylon and engine were torn off. Part of the leading edge of the wing was also damaged and the use of several systems was lost or limited. This subsequently left the flight crew with very limited control of the airplane. Due to the resulting marginal degree of controllability, a safe landing became highly improbable, if not virtually impossible. In case of excessive loads on the Boeing 747 engines or engine pylons, designed to fracture cleanly are fuse pins holding the engine nacelle to the win allowing the engine to fall away from the aircraft without any damage whatsoever to the wing or wing fuel tank. In case an engine fails, airliners are designed to remain airworthy so that the plane can be landed safely. Damage to a wing or wing fuel tank can be disastrous. It was discovered the Netherlands Aviation Safety Board that the fuse pins had not failed properly, but instead had suffered metal fatigue prior to overload failure. The following are the probable sequence of events for the loss of engine 3: 1. There was gradual failure by fatigue which resulted to overload failure of the inboard mid-spar fuse pin at the inboard thin-walled location. 2. An Overload failure of the outer lug of the inboard mid-spar pylon fitting. 3. Failure of the outboard mid-spar fuse pin at the outboard thin-walled and fatigue-cracked location as a result of overload. 4. An overload failure of the outboard mid-spar fuse pin at the inboard thin-walled location. This step-by-step sequence of failures was probably the reason the engine and pylon broke free thereby knocking outboard engine 4 and its pylon off the wing as well and in the process inflicted serious damage on the leading edge of the right wing, including the control surfaces (flaps) that was later tried to be extend in flight, by Captain Fuchs. The plane only managed to maintain level flight at first as a result of its high air speed (280 knots). It was now much more difficult to keep the plane level as a result of the damage to the right wing resulting in reduced lift. At 280 knots, there was sufficient lift on the right wing to keep the plane aloft. Once the plane reduced speed for landing it was doomed because there was not enough lift on the right wing to enable stable flight, and as a result of this, the plane banked sharply to the right without any chance of recovery. Failures that might have contributed to the crash The original engine pylon design might not have been optimal, and the fact that airworthiness measures and inspection systems did not guarantee the minimum safety requirement level, are some failures within the major aircraft systems that might have contributed to the crash. The Boeing-747 pylon design and certification was found to be inadequate for providing the required safety level. Furthermore, there was also a failure of the system of ensuring structural integrity through inspection. This might have caused fatigue in the inboard midspar fuse-pin, resulting in the separation of the no. 3 pylon and engine from the wing, leading to the no. 4 pylon and engine being torn off. Hence, part of the leading edge of the wing was damaged and there was loss of several more systems in the aircraft. "This subsequently left the flight crew with very limited control of the airplane. Because of the marginal controllability a safe landing became highly improbable, if not virtually impossible." (Flight safety foundation accident prevention 1996) A review of the aircraft systems that might have been affected by the engine separations After investigation it was determined that there was a gradual failure by fatigue that resulted in an overload failure of the inboard mid-spar fuse pin at the inboard thin-walled location. The NASB ascertained that the sequence of the accident was initiated by the in-flight disintegration of the number 3 engine pylon from the wing. Engine and pylon number 3 separated from the wing and collided with engine number 4, in an outward and rearward direction. In view of the amount of LE flaps and LE structure found, the right wing leading edge must have been damaged up to the front spar of the right-hand wing, over an area of about 3.3 feet left of pylon number 3 to about 3.3 feet right of number 4. (Flight safety foundation accident prevention 1996) There also resulted an overload failure of the outer lug of the inboard mid-spar pylon fitting, and after the separation of the number 3 and 4 pylons, the crew may have been forced to fly the aircraft under dire circumstances because the right wing leading edge must have been damaged severely, and there would have been little or no rudder control due to the lagging of the lower rudder. The failure of the outboard mid-spar fuse pin at the outboard thin-walled and fatigue-cracked location as a result of overload probably caused an overload failure of the outboard mid-spar fuse pin at the inboard thin-walled location. Due to the speed of the B-747, turbulence, and the aerodynamic distortion, some parts of the aircraft might have been blown off the leading edge of the right-hand wing as far as the front spar. After investigating the crash, Boeing issued a service directive about the faulty fuse pins on Boeing 747 aircraft. The engines of the aircrafts were removed and checked for any cracks in their fuse pins. Faulty fuse pins on the aircrafts were then replaced References El Al Flight 1862 accident record, ASN El Al Flight 1862 (retrieved from http://en.wikipedia.org/wiki/El_Al_Flight_1862) EL AL FLIGHT 1862. Nederlands Aviation Safety Board Uijt de Haag P.A. and Smetsers R.C. and Witlox H.W. and Krus H.W. and Eisenga A.H. (28 August 2000). "Evaluating the risk from depleted uranium after the Boeing 747-258F crash in Amsterdam, 1992". Journal of Hazardous Materials 76 (1): 39-58. doi:10.1016/S0304-3894(00)00183-7 . Retrieved on 2007-05-16 Flight safety foundation accident prevention (1996) Vol. 53, No. 1. (Retrieved from http://www.flightsafety.org/ap/ap_oct96.pdf) Greenberg, Joel. "Nerve-Gas Element Was in El Al Plane Lost in 1992 Crash", New York Times, 1998-10-02. Retrieved on 2007-10-11 Henk van der Keur (May 1999). Uranium Pollution from the Amsterdam 1992 Plane Crash. Laka Foundation. Retrieved on 2007-05-16 Read More