Note: we refer Readers to this analysis with diagrams.
Note: The Wall Street Journal has this in-depth piece (found via Google News, so Readers should be able to access it) that says:
- The fire was in the overhead area over the last rows of the airplane;
- “Boeing has been reviewing systems in that area of the jet that would remain powered by the attached ground power supplied by the airport, the person said.
“What those systems are couldn’t immediately be determined. So-called remote-power distribution units, which act as substations for the 787’s electrical system, and remote-data concentrators, which help distribute data signals to systems from the jet’s central computer, are installed throughout the aircraft—including units next to one another in the ceiling of the jet near the last set of doors on the Dreamliner, where the fire damage appears;” and
- “The back area of the 787 also includes a galley behind the last row of seats on Ethiopian’s 787s. One person familiar with the analysis of the fire said the galley is also a focus for investigators. Galleys have various heat-producing equipment, such as ovens and coffee makers. Problems with such equipment in the past have caused fires on parked planes.”
There are a myriad of questions to answer in the July 12 fire of an Ethiopian Airlines Boeing 787. Some probably are already known to investigators but most are not, and as yet the public hasn’t been informed by the British Air Accident Investigation Board (AAIB).
What we, the public, knows (or think we know) at this point is (in no particular order):
- The 787 was parked for eight or more hours on a remote ramp;
- The airplane, according to the New York Times, was hooked up to ground power;
- Also according to the NYT, the flight was 4 1/2 hours from departure;
- The lithium-ion batteries aren’t involved, according to the AAIB;
- According to the Financial Times, quoting an unidentified airline person, sparks were observed from the air conditioning unit about eight hours before the fire, but we have some skepticism over the accuracy of this report (we don’t doubt the Times accurately reported what it was told but we are skeptical of what it was told);
- The fire obviously burned through the skin crown.
Here are the speculative rumors so far (that we have seen), (in no particular order):
- The fire started in the galley;
- A coffee pot was left on;
- The fire started in the air conditioning unit;
- The fire started somewhere other than the crown area and propagated to the crown;
- The fire started in the crew rest area (later discarded because Ethiopian doesn’t configure its 787s with a crew rest area in the proximity of the fire);
- The electrical system has a new fault and this is where the fire started.
So here are the questions we have (in no particular order):
- Where did the fire originate? We understand investigators already know but they haven’t made this public.
- How did it originate?
- What equipment, either as part of the 787 systems or a vendor-supplied component, was involved?
- How long was the fire burning?
- How was it detected? (Obviously someone knows, but we haven’t seen a public report on this.)
- If the plane was hooked up to ground power, was the power actually turned on?
- If the power was turned on, why was it on for eight hours (or however long)? (It strikes us that having ground power on for up to 12 hours before a flight is unnecessary and raises a number of questions.)
- If the power was on for an extended period, what if any contribution did this have to the fire?
- If the power was on for a short period of time, ditto to #8, and why would this have any impact (if it did)?
- If the plane was hooked up but the power was actually off, what “woke up” the parts of the plane to cause a fire?
- Was the air conditioning story true and if so, what if any maintenance was performed to track down a sparking A/C?
- Was the galley involved? If so, why wasn’t there some fail-safe switch to switch it off to prevent overheating (or why didn’t it work it there was)?
- Was there some sort of human-induced issue?
- Was a vendor-supplied component at the heart of the matter?
- Was there something lingering within the plane’s systems from the inbound flight that “smoldered” undetected all this time before the fire occurred? (Happens in house fires all the time.)
- And, of course, can the airplane be repaired and returned to service?
There are clearly more questions to be answered, but this is a start.