January 28, 2008...6:31 am
Modern jets are incredibly safe, but the British Airways 777 crash-landing sends alarms through the whole aviation industry
The recent incident at London Heathrow airport which saw a Boeing 777 crash-land after both its engines failed to deliver the required thrust just before touchdown will be making every pilot who flies this aircraft and every airline that operates it more than a little nervous until the cause is found. This includes Air New Zealand, which has eight of the 594 of them operating with many airlines around the world. An incident like this simply should not happen. Modern jet aircraft have extensive failsafe systems to ensure that even if one engine fails, the other, or others, will keep going. Nothing like this appears to have happened before with this big wide-body twin jet, which had not been in a single crash since the prototype first flew in 1994.
To recap. British Airways Flight 38 was on its final approach to Heathrow on January 17 carrying 152 passengers and crew on what had been an uneventful run from Beijing. It was being flown by First Officer John Coward, with Captain Peter Burkill taking the co-pilot role. The jet came in on autopilot and autothrottle, as is standard at Heathrow. About two miles from touchdown and at 600 feet, the autothrottle demanded an increase in thrust, but the engines did not respond. First Officer Coward pushed the throttle levers forward to increase thrust manually, but again nothing happened. Big jets can glide, but at such a low speed and so close to the ground, there was an immediate risk of a catastrophic stall. First Officer Coward pushed the plane’s nose down to pick up speed. He was able to get the 777 over the airport boundary fence, where it stalled and hit the ground 1000 feet short of the runway. The landing gear was ripped off, one wing was severely damaged and a large amount of fuel gushed out, but there was no fire. The cabin crew followed emergency procedure to the letter, quickly evacuating the passengers down the slides. Some suffered mostly minor injuries.
Modern jet aircraft are amazingly safe. Travelling a number of times on the flight decks of jets ranging in size from a 737-300 to a 747-400 has given me complete confidence in flying. Their navigation equipment includes screens that not only show exactly where the plane is (no more flying into mountains, as happened with the Air New Zealand Antarctic flight in 1979), but also the location of every other plane in the sky around. If another plane, or the ground or a mountain, comes too close, a computer shouts a warning to take evasive action, even instructing which way to turn.
As already mentioned, these big planes glide, very well. On a typical flight between Auckland and Wellington, the engines go to idle just past Taranaki and the jet glides almost all the rest of the way, slowly losing height while saving fuel. There have even been cases of jetliners gliding to safety when their engines have failed. In 1983, an Air Canada 767 on a flight from Montreal to Edmonton ran out of fuel at 41,000 feet because it was mistakenly refuelled in imperial pounds rather than kilograms, meaning it took off with half the fuel needed. Its pilot safely glided it to land at a former military airstrip. The year before, a British Airways 747 flew through a cloud of volcanic ash over Indonesia, causing all four engines to fail. The pilots glided down for 16 minutes before successfully restarting the engines. But these were cases of immediately identified causes of engine failure, and they occurred high enough for the pilots to recover. BA 38 lost power (the engines did not stop, they did not deliver extra thrust when needed) when too low and too slow to glide properly.
A twin-engined jet like a 777, 767, 737 or Airbus A320 can safely fly on one engine, even if the other engine fails at a critical moment, such as takeoff or landing. In December 2002, an Air New Zealand 767 taking off from Brisbane for Auckland suffered an uncontained turbine fan failure in the left engine. Pieces of the fan blade sheared off and broke through the engine cowling, damaging the wing and fuselage. But the plane was able to turn around and land safely on its remaining engine. The cause was later identified as metal fatigue in the fan blade.
But a modern jet is designed so that, absent any direct cause such as running out of fuel or flying through a volcanic plume, its engines should not all stop working properly at the same time. That is why alarms are ringing over the British Airways Heathrow incident and why identifying the cause is a matter of urgency, lest there be some inherent fault with the 777 that could see it happen again.
British Air Accidents Investigation Branch investigators are reportedly concentrating on the engine fuel supply system and the quality of the fuel loaded in Beijing, having established that the engine control commands worked normally and the aircraft was found to have an adequate amount of fuel when it was examined after the crash-landing. Some pilots reportedly believe that the plane’s difficulties could hinge on the failure of fuel to reach the engine. Investigators are examining the “complete fuel flow path” from the aircraft tanks to the engine fuel nozzles. So far, aviation regulators such as America’s Federal Aviation Authority have found no reason to issue any directives to 777 operators or demand their grounding. You can be fairly sure an answer will not be long in coming. Meanwhile, First Officer John Coward deserves every one of the accolades showered on him.
Footnote: The Air Canada Boeing 767 that glided to a safe landing in 1983 made its final flight just four days ago. The jet became known as the “Gimli Glider” after Gimli, the airstrip it landed at. Air Canada’s staff newsletter carried this item last week to announce the event: On Thursday, January 24th, fin 604, the Boeing 767-200 better known as the Gimli Glider, will undertake its final voyage from Montreal to Mojave Airport before it is retired to the desert. Employees and retirees are invited to come and say goodbye to the aircraft which has now become part of Canadian aviation history. Fin 604 is set to depart as flight AC7067, at 9am from the Montreal Line Maintenance hangar. Captain Robert Pearson and First Officer Maurice Quintal, the flight crew who landed the aircraft to safety in Gimli on July 23, 1983 are expected to be on hand for the aircraft’s departure.
2 Comments
January 28, 2008 at 1:14 pm
Having flown in an Air NZ Boeing 777 with that aircraft performing admirably, in May 2007, from Auckland to Heathrow via Los Angeles on route to Cambridge it can be said that with the two characteristically large engines inspiring confidence and the cabin supplemented with in-flight personal entertainment systems the trip was relatively comfortable and passed without controversy except for the minor incident when the passenger next to me just could not figure out how to work his in-flight entertainment system control. With the flight’s second leg from LA unfortunately flying over clouds most of the way especially over and beyond Canada the usual magnificent site of seeing the icebergs streaming past lower Greenland was missed.
While investigations are concentrating on the fuel and fuel systems of the Boeing 777 that had the unfortunate landing at Heathrow, it has now come to light that this make of aircraft has had six other separate single engine failures logged by American investigators although not in any aircraft with two engines simultaneously other than this latest incident. Perhaps if Chinese re-fueling proves to be the culprit, as currently being considered, then traveling to Heathrow via LA would seem the better option.
January 29, 2008 at 11:05 pm
Having been a technician for a major airline , I am also surprised that an urgent FAA directive has not been issued. It maybe under investigation but a two engine failure is beyond serious. Times have changed and more reliance on electronics is understandable but it doubles up the checking and inspections. So more electronic montoring is required and the cycle expands.
I was involved in the reporting of the Boeing 737-400 crash at Kegworth UK and it fell 200m short of the runway and into the M1 motorway.
The finding on this brand new plane was a mix up with vibration meters and new instuments resulting in the shutdown of the good engine on approach.
Pressures on the last two manufacturers are huge.
Thankfully the standards are still very high.
Lets hope it’s just a fueling stuff up in China.
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