Shortly after 13:40 UTC (20:40 Jakarta time) above the Indian Ocean, south of Java, the flight crew (consisting of 32-year-old Senior First Officer Roger Greaves and 40-year-old Senior Engineer Officer Barry Townley-Freeman while 41-year-old Captain Eric Moody was in the lavatory) first noted an effect on the windscreen similar to St Elmo's fire.[1] The phenomenon persisted after Moody returned from the lavatory. Despite the weather radar showing clear skies, the crew switched on engine anti-ice and the passenger seat belt signs as a precaution.
As the flight progressed, smoke began to accumulate in the passenger cabin of the aircraft; it was first assumed to be cigarette smoke. However, it soon began to grow thicker and had an ominous odour of sulphur. Passengers who had a view out the aircraft windows noted that the engines were unusually bright, with light shining forward through the fan blades and producing a stroboscopic effect.[3]
At approximately 13:42 UTC (20:42 Jakarta time), the number four Rolls-Royce RB211 engine began surging and soon flamed out. The flight crew immediately performed the engine shutdown drill, quickly cutting off fuel supply and arming the fire extinguishers. Less than a minute later, at 13:43 UTC (20:43 Jakarta time), engine two surged and flamed out. Within seconds, and almost simultaneously, engines one and three flamed out, prompting the flight engineer to exclaim, "I don't believe it—all four engines have failed!"[3]
Without engine thrust, a 747-200 has a glide ratio of approximately 15:1, meaning it can glide forward 15 kilometres for every kilometre it drops. The flight crew quickly determined that the aircraft was capable of gliding for 23 minutes and covering 91 nautical miles (169 km) from its flight level of 37,000 feet (11,000 m).[3] At 13:44 UTC (20:44 Jakarta time), Greaves declared an emergency to the local air traffic control authority, stating that all four engines had failed. However, Jakarta Area Control misunderstood the message, interpreting the call as meaning that only engine number four had shut down. It was only after a nearby Garuda Indonesia flight relayed the message to Air Traffic Control that it was correctly understood. Despite the crew "squawking" the emergency transponder setting of 7700, the 747 could not be located by Air Traffic Control on their radar screens.
Many passengers, fearing for their lives, wrote notes to relatives. One such passenger was Charles Capewell, who scrawled "Ma. In trouble. Plane going down. Will do best for boys. We love you. Sorry. Pa XXX" on the cover of his ticket wallet.[2]
Owing to the high Indonesian mountains on the south coast of the island of Java, an altitude of at least 11,500 feet (3,500 m) was required to cross the coast safely. The crew decided that if the aircraft was unable to maintain altitude by the time they reached 12,000 feet (3,700 m) they would turn back out to sea and attempt to ditch into the Indian Ocean. The crew began engine restart drills, despite being well outside the recommended maximum engine in-flight start envelope altitude of 28,000 feet (8,500 m). The restart attempts failed.
Despite the lack of time, Moody made an announcement to the passengers that has been described as "a masterpiece of understatement":[3]
Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress.[3][4][5]
As pressure within the cabin fell, oxygen masks dropped from the ceiling – an automatic emergency measure to make up for the lack of air. On the flight deck, however, Greaves's mask was broken; the delivery tube had detached from the rest of the mask. Moody swiftly decided to descend at 1,800 m per minute to an altitude where there was enough pressure in the outside atmosphere to breathe almost normally.
At 13,500 feet (4,100 m), the crew was approaching the altitude at which they would have to turn over the ocean and attempt a risky ditching. Although there were guidelines for the water landing procedure, no one had ever tried it in a Boeing 747, nor has anyone since. As they performed the engine restart procedure, engine number four finally started, and at 13:56 UTC (20:56 Jakarta time), Moody used its power to reduce the rate of descent. Shortly thereafter, engine three restarted, allowing him to climb slowly. Shortly after that, engines one and two successfully restarted as well.[6] The crew subsequently requested and expedited an increase in altitude to clear the high mountains of Indonesia.[7]
As the aircraft approached its target altitude, the St Elmo's fire effect on the windscreen returned. Moody throttled back; however, engine number two surged again and was shut down. The crew immediately descended and held 12,000 feet (3,700 m).
Damn, that was a good read.