The same viewpoint as seen by the 747 that lost power near Bangkok a week earlier, courtesy Qantas
A week before a Qantas 747-400 suffered a series of electrical failures while fortuitously close to Bangkok Airport on January 7, 2008, it had been above Antarctica, on a scenic charter flight, and many hours away from Australia.
Three of the jet’s four GCUs or generator control units had been flooded and knocked out by water from a blocked, and probably partly frozen waste pipe draining a galley where coffee grounds often clogged the sinks.
As detailed in today’s final ATSB report into the serious incident, the electrical failures caused by the plumbing problems took down a range of important controls and systems, and confronted the pilots with a mass of error messages on their cockpit displays. Rather like a vanilla version of the far more severe issues that confronted the crew of a Qantas Airbus A380 on November 4 near Singapore.
But there was a really nasty side to this incident, on flight QF2 from London, with 346 passengers and 19 crew on board, compared to the structural challenges faced by the A380. The Boeing 747-400 was running out of electricity. When it pulled up at the terminal there was only 14 minutes of 30 minutes of emergency battery power remaining.
Without that power, fuel transfers between the 747s tanks would have been compromised, and the crew would have needed to fly and navigate using a basic set of stand by instruments, no better in many respects than the instrumentation of a light plane.
The ATSB report warns of the risks this situation posed to safety-of-flight. This is an understatement. When this incident occurred nearly three years ago there was a widespread view among pilots qualified to have a view about 747 operations that the jet would not have made it very far in its bid to reach, say, Hobart, and almost certainly without radio links.
The report also points out that the drainage issues on the Qantas 747-400 concerned were found in 18 out of 30 of the jets that were in service with it at the time, and that a specific protection against water contamination in their electrical bays called a drip shield was found to be obviously damaged in many cases.
The high proportion (52 out of 69) of damaged dripshields or gutters in the operator’s 747‑400 fleet of aircraft indicates that the issue was widespread, even though that particular problem could have been readily identified by a visual inspection during regular maintenance activities.
However the report completely avoids discussing how the maintenance of these jets, most of which was done in Australia, could have been so derelict as to have neither noticed nor acted upon the obvious damage.
The general location of the problem areas, and an example of the obvious water related corrosion are set out in the report, as below.
These are the control and system failures that occurred as the flight was descending toward Bangkok Airport:
• AC buses 1, 2 and 3 not powered
• autothrottle disconnected
• autopilot disengaged
• some fuel pumps not operating
• weather radar not operating
• automatic cabin air conditioning and pressurisation system not operating
• right (FO’s) displays blanked
• between three and five pages of messages on the EICAS display
• lower EICAS display blanked
The status of AC bus 4 appeared normal. The flight crew reported observing main battery and auxiliary power unit (APU) battery discharge messages on the EICAS. The battery discharge messages were classified in the operator’s flight crew operations manual (FCOM) as advisory[1] and did not require crew actions. The operator’s quick reference handbook (QRH) stated that these messages indicated that the associated batteries were discharging. The QRH did not provide the flight crew with information about the remaining battery life, nor any recommended crew actions to restore services. The EICAS messages were not time stamped.
The flight crew reported that they actioned several non-normal checklists in response to a number of other messages and annunciations. However, after a period of time the flight crew decided to discontinue actioning the non-normal checklists due to the constant action required in response to the continuous scrolling of the EICAS messages.
The EICAS and overhead panel annunciations indicated that three of the four AC buses remained unpowered. The flight crew reported that they also checked the flight deck circuit breakers, and none of them appeared to be open. The flight crew reported that they did not have sufficient time to refer to the aircraft’s manuals to diagnose the problem.
The flight crew stated that the following instruments and systems were available:
• left (captain’s) primary flight display (PFD), in a degraded mode, which included attitude, airspeed, altitude, vertical speed and instrument landing system indications
• left navigation display (ND), in a degraded mode
• left control display unit
• upper EICAS display, including landing gear indication
• standby instruments, comprising attitude indicator, airspeed, altitude, and magnetic compass
• right flap position indications
• one radio communications system.
In addition, the flight crew reported that during communications with air traffic control, they noticed that the strength of the radio transmissions were less than normal.
It was also reported that engine pressure ratio (EPR) readings were only available for the No 4 engine. The probe for the measurement of EPR for each engine was powered by the associated AC bus.
The report details actions that Qantas, Boeing and the FAA have taken in response to the incident which the ATSB says will address a range of safety issues.
However as reported in an earlier post today, the ATSB was also rebuffed in its pursuit of changes to the quick reference handbook for 747-400 operations in relation to such failures, and ignored by the US Federal Aviation Administration in relation to its criticism of the regulations it has in place which the Australian agency says inadequately address the cumulative, and often overlooked effects liquid spillage in a cabin can have on airliner electrical systems.
The ATSB also details similar incidents, as well as some ‘dry’ but relevant electrical system failures in a range of other airliner types, and whether by accident or design, lists some responses the FAA had made to incidents involving Airbus types, yet resisted in the case of the Boeing 747-400 situation.
There is, for those interested in the inconsistencies of international air safety regulation, quite a bit of reading to do in this report.
It is also important to note that Qantas has been sufficiently concerned about the risks of a 747 being reduced to the use of standby instruments of questionable durability or applicability in a similar incident that it has embarked on its own program of installing a new integrated standby instrument system in its fleet of 27 of these jets.
1.1.1 Aircraft instrumentation
Although no safety issue was identified in respect of the aircraft’s instrumentation, in response to this occurrence, the aircraft operator initiated a project to install an integrated standby flight display (ISFD) system in its 747‑400 fleet to facilitate aircraft navigation in the event of a complete failure of some or all main aircraft indication systems. The ISFD has the capability to provide an integrated, self‑illuminating display of the following parameters for up to 150 minutes:
• pitch and roll attitude
• indicated airspeed
• altitude
• heading
• localiser and glideslope deviation.
The modification is planned for completion by the end of 2011. As of 25 October 2010, 15 aircraft had undergone the modification.
16 Comments
Ben,
again, the dice rolled and came up six. QF have been VERY lucky, in ALL the incidents.
What is the matter with this airline? There was a time when people travelled with QANTAS because it was deemed to be safer than Over Seas airlines. It’s as if the ‘little battler syndrome’ of their ground staff has spread to the engines and structure of the planes. I would prefer to travel on a Russian built Yak-as I have said in the past.
Damaged or missing drip shields are, as you say, obvious to the casual observer. Which raises the issue, how and why, and why was this not covered in the ATSB report?
“However the report completely avoids discussing how the maintenance of these jets, most of which was done in Australia, could have been so derelict as to have neither noticed nor acted upon the obvious damage.”
The picture show the effect of electrolysis.
And it lookes like the result of longtime dripping ,
nothing that went wrong just one time.
Uwe,
Spot on. The ATSB exhaustively describes this as a long term issue for airliners in general, and is clearly exasperated by the unwillingness of the FAA to revise its regulations concerning the problem. It had also been staring Qantas in the face, with evidence of the problem found to be widespread in its 747s and some 767s, yet the airline did nothing.
Any similarities to the rather cavalier handling of the “burning windscreen” issue
Boeing has over all types?
Couldn’t all this have been avoided at the design stage? The MEC is directly below the galley and has one breakable drip tray to protect it if the plumbing fails. And what about that? I avoid putting coffee grounds down the sink at home because it can block the sink but I’d be a whole lot more asiduous if my life depended on it.
Better no galley on top of indispensable instrumentation.
In IT you don’t but the coffee machine on top of the server cabinet either.
Hi, new to this blog. I have always respected your knowledge of the air transport scene in Australia & elsewhere, so I read this post with interest. Just one point casts some doubt for me, though, which I hope you can explain… namely the image of wing & engines above a snowy mountainous wilderness, is captioned ” photo taken from the SAME a/c”. The image shows that this particular a/c is one of the GE-powered fleet. Then I read the ATSB report which first-up lists the a/c involved as being VH-OJM, in other words one of the original RR-powered fleet. You can see how the credibility of the entire post might be compromised in my mind. Respectfully, Bear.
Bear,
The photo, courtesy Qantas, was supplied with a press release in advance of the following season’s Antarctica sightseeing charters by Croydon Travel and identified as having seen the New Year in over Antarctica the previous season, that is, at midnight, on December 31, 2007, in broad daylight of course at the height of the southern polar ‘summer’. I reported the Bangkok incident in the Crikey subscriber bulletin, as Plane Talking had not been launched at that stage. In the course of those reports Qantas confirmed claims on Pprune that the jet involved in the Bangkok incident had performed the New Year’s eve Antarctica flight the previous week.
However you make the unarguable point that if I had checked the external clues on the engine I would have realised this could not in fact have been the same jet that was involved in the Bangkok incident. To be frank, that never occurred to me as being material, but it is an error and well spotted. The caption has been corrected.
The jet involved in the Bangkok incident did perform the polar sightseeing charter, and in the aftermath of that incident there was considerable discussion among Qantas pilots as to how manageable the jet would have been had the water damage manifested itself the way it did near Bangkok while south of the Antarctic circle.
Whether it renders my report wrong or not, I maintain that the major issues are inescapable. Qantas maintenance ignored obvious signs of water damage fleet wide in the area where the Bangkok electrical failures had their origin.
Ben,
As you say, the substance of the post, stands regardless. No disrespect intended.
As for the image and the supposed role played by the a/c it depicts, I can only say that: “to err is human, but to REALLY muck things up, takes the PR Dept. of a large corporation!” (as the good folks at QF are finding out now about RR).
I look forward to reading more of your work.
Season’s Greetings, Bear