خلل ميكانيكي وراء سقوط طائرة عزة بالشارقة و بوينج تؤكد ان الكابتن تصرف بشهامة

Quote: The simulation of reverse thrust at high power predicts that the airplane can be controlled for the worst case condition but only with timely input of large wheel and rudder. The simulation roughlymaintained the runway heading. Full rudder was utilized along with full wheel to recover the initialupset after waiting one second. After the initial upset recovery, it took full rudder, approximately 50degrees of wheel, and 9 degrees of opposite bank angle to maintain airplane heading in the worst casecondition. Any less input would have the Aircraft heading turn right which is the direction the accidentAircraft took. It should also be noted that the simulation is predicting for this condition that the Aircraftsideslip angle approached 10 degrees. At sideslip angles greater than 10 degrees the linearityassumptions of the aerodynamic model begin to lose their fidelity

Quote: HISTORY OF FLIGHT On October 21st, 2009, at approximately 1130 UTC, a Boeing 707-330C (cargo) Aircraft, registrationnumber ST-AKW departed Sharjah International Airport with no reported mechanical anomalies. TheAircraft took off from runway 30 to Khartoum, Sudan, with a total of six persons onboard: three flightcrewmembers (Captain, First Officer and Flight Engineer), a Ground Engineer and two Load Masters,along with cargo of air conditioning units, auto parts, computers, personal effects, and some tools.After takeoff, and during initial climb, the cowling of engine No. 4 separated from the Aircraft and felldown onto the departure runway. The Aircraft continued in a shallow climbing with level wings when the pilot informed the Air TrafficControl that he lost engine No. 4. A few seconds later, the Aircraft veered to the right in comparison tothe initial takeoff flight path and finally went into a right turn associated with approximately 70 degreesright bank, dived and impacted the ground at approximately 1.6 kilometres from the end of the SharjahAirport runway about 20 seconds after takeoff. The high impact forces caused an explosion, subsequent fire, and completely destroyed the Aircraft

Quote: Wreckage analysis discovered the engine's core thrust reverser was in a deployed position, as were the outer translating sleeve and the right-hand reverser clamshell. The left-hand clamshell was also "beyond the normally-stowed position",

(عدل بواسطة abubakr on 02-16-2011, 07:16 PM)

Quote: [الحادث] .. كان نتاجا عطل في جهاز الدفع الخلفي the thrust reverser حيث اشارت تحليلات الصندوق الاسود ان عتلة جهاز الدفع الخلفي في الجانب الايمن من الكابينة كان في وضع التشغيل وان وضع قشرة ال (clamshell) في ماكينتي الجانب الايمن اكدت ان جهاز الدفع الخلفي تم تشغيله اثناء عملية الاقلاع ( التشغيل ربما كان دون قصد او نتيجة لخلل في المنظومة( ..

Quote: reversers on the JT3D engine consist of a forward fan thrust reverser, and an aft core thrustreverser.Flow reversing components on the forward thrust reverser are located circumferentially around thefirst stage compressor case. During forward thrust operation, the exhaust air from the fan section ofthe first stage compressor is discharged in the aft direction from a duct created by the powerplantdiaphragm and engine cowl ring assembly.During reverse thrust operation, the forward thrust reverser actuators move the cowl ring aft andreposition the blocker doors, lower vane assemblies, and baffle assemblies to discharge the fan air in aforward direction.The aft thrust reverser, during forward thrust operation, is an intermediate path for exhaust gas flowbetween the engine and tail pipe.During reverser operation, the aft thrust reverser actuators move the aft thrust reverser sleeverearward uncovering the cascade assemblies. Movement of the sleeve causes the clamshell doors toclose through the action of a hinge drive mechanism connecting the sleeve and clamshell door hingearm. Engine exhaust gases are diverted through the cascade vane assemblies.The T/R control system directs pneumatic pressure to actuators of the forward and aft thrust reverserswhich position the flow reversing components. The system consists of the reverse thrust controlsmounted on the thrust control shaft and on the engine controls strut bracket, forward thrust reverserfollow-up linkage, aft reverser follow-up linkage, hinge-drive mechanism, forward and aft actuators,and miscellaneous system components (Figure 1). The reverse thrust controls consist of a thrust reverser directional control valve, a rocker armmechanism, a thrust lever actuating cam, forward thrust reverser interlock cam, aft thrust reverserinterlock cam, aft thrust reverser follow-up pulley, forward thrust reverser follow-up crank, and twoconcentric shafts on which the interlock cams, follow-up crank, and follow-up pulley are mounted. Thethrust lever actuating shaft is installed on the lower end of the thrust control shaft. The other reversethrust controls are installed on the engine controls strut bracket, which is mounted over the lower endof the throttle and start shafts [/QUOTE ] من تقرير سلطة الطيران المدني الاماراتية