Recently, a visitor left a comment to one of my posts dealing with the B777, actually it was a question. He was worried about the crash landing of the British Airways 038 and since he’s going to board a “triple seven” he asked me if this aircraft is safe. My answer was that I will be flying an Alitalia B777 too at the end of February and I feel quite comfortable with the idea of flying that kind of aircraft. In fact since before BA038 accident, there had never been an accident that destroyed a 777, an aircraft that is flying in 687 examples from 13 years and that has logged some 3.5 million flight hours. Furthermore, recent crash drew more attention on the aircraft systems and engines and most probably, there will be even more focus on safety, procedures, etc in the next months. If something surfaces from the investigation dealing with the engines and/or engine control systems, upgrades will be required to keep the fleet flying and, for example, in the meanwhile the model would be restricted from operating ETOPS 180 over the oceans.
That said, I must add that the number of engine failures experienced by the 777 fleet requires an in-depth investigation. In the last months, twice an Air France B777 flying from Paris Orly to La Reunion experienced engine troubles and had to divert to Rome Fiumcino (Dec 12th 2007) and Malpensa (Jan 25th 2008). There have been 7 IFSD (In Flight Shut Down) or engine problems with the B-772ER and 773ER operated by the AF, but also other fleets have suffered a certain number of IFSD and other engine failures (El Al, Singapore, Malaysian, to name but few). Failures occurred on both GE and RR equipped aircraft meaning that the problem is probably in the control systems (FADEC ?) and not in the engines.
Going back to the BA 038 crash landing, even if the report hasn’t been issued yet, an alleged leaked report appeared on many forums and blogs on the Internet. I found it at the following address: http://snipurl.com/1yr29. According to it the investigation is concentrating in the following possible causes (some of which were already analysed on this blog):
• Fuel flow limited by ice or contamination
• Engine hardware failures
• Software coding problem “British Airways installed a new engine EEC software revision in December 2007. The software was approved in May 2006. There were several changes to the software as part of the revision”.
Noteworthy, the report states that the APU was started before the crash landing even if, due to insufficient time, the APU fuel pump didn’t turn on and the APU engine didn’t start spooling up. Maybe the pilots thought to a power loss when the throttle didn’t react to request of thrust. Another interesting information deals with the RAT (Ram Air Turbine) that was found deployed leading to an electric power loss; however the RAM was probably deployed after impact.
This “leaked” report doesn’t mention any possible interference of the signals caused by mobile phones, laptop, WiFi etc. I already said that this theory in my opinion should be discarded because the engine control wires are very well shielded in order to prevent signal’s corruption but many websites pointed to the radio frequency interferences as the root cause of the Heathrow accident. For instance, Qantas has been testing since 2007, a system that allows passengers to send text messages and emails from their mobile phones during normal commercial flight, using the plane’s airframe as a mobile phone tower. The technology trial involved a B767 travelling on Australian domestic routes; for the moment the trial doesn’t allow any voice service, not for the risk of interference but for the need to prevent passengers from being disturbed by other passengers talking on the phone. In August, the first Qantas A380 on commercial route will be a high-tech plane providing WiFi connectivity throughout the fuselage and Internet access via satellite. There will be ethernet and USB ports, power sockets and many more useful thing that will enable passengers to surf from the seat. Even if the 767 trial is still in progress and final report will be released later this year, the test programme and the A380 in the “flying network” configuration show that wireless interference should not be a risk factor for a modern aircraft but what about hacking the internal entertainment system (and more) with a laptop plugged in one of the internal sockets?