D. The Role of The Flight Engineer during Emergencies

lt is possible to see, in the Thai lpternational accident of October 1986, the difficulty that confronts the pilots of a two man crew complement aircraft when they have to cope with the increase in workload when unexpected trouble occurs. The Thai International Flight 620 (two man crew complement A-300) simultaneously suffered decompression and the loss of two of its three hydraulic systems with a pilot making an emergency descent to an altitude with sufficient oxygen. ATC tried persistently to communicate with Thai Inter 620 because it was making an violent descent and changing course, entering a prohibited area without permission. The pilot stated later that he knew ATC was alerting them but that there was no time for them to respond.
Simultaneous hydraulic failure and decompression is a situation that is not even experienced during training. Due to the use of the exygen mpsks communication was difficult, with one pilot flying the aircraft while the other was turning the pages of the EICAS (which is not capable ofverbal communication) and trying to execute emergency procedures, because the handbood type checklist had mown out of the cockpit due to decompression, the cockpit must have been in a chaotic state. They were finally able to contact ATC after entering the prohibited area.
When the aircraft landed at Osaka Airport, it was unable to taxi on its own due to failure of the hydraulic system and a towing car had to be quickly prepared. Only after the doors were opened did the officials realize the injuries that the passengers had sustained and that there was an urgent need to get emergency medical aid to them. The aircraft had to land as quickly as possible, there was nottime for the night crew to evaluate the condition of the passenger cabin or to communicate with the ground. It was not possible for the two man crew complement to cope with the situation to that extent.
However, in the case of JAL Flight 123, in which a B747-100SR lost its vertical stabilizer and all four hydraulic systems, the night engineer was able to:

-maintain communication with the passenger cabin, -evaluate the condition of the aircraft, discuss and give advice concerning the emergency procedures using the emergency checklist, -communicate over the radio with ATC and the company in place of the pilots, -cncourage the pilots flying the aircraft under tremedous strain.

The actions taken by the fight engineer of this flight, under these extreme circumstances, was found to be highly commendable.