A few months ago I wrote about the events surrounding a British Airways
flight from Los Angeles to London (AIN, December 2006, page 78). This was not just any flight; it was accomplished with one engine shut down. I have spoken to many aviators since my article appeared, and one thing is clear: there are a lot of opinions on the subject. To recap the facts: a British Airways 747-400 was taking off when its number-two engine emitted a large fireball. The flight crew followed procedures and continued to a safe altitude to assess the situation. This crew received a high level of cooperation from the air traffic controllers who were working the normally busy Los Angeles area.
The tower controller saw the fireball, so preparations were in motion before the crew declared their need to hold at altitude and explore their options. As the aircraft was climbing, the crew communicated some of their actions to ATC.
When the tower controller reported the fireball, the crew’s initial response was that it was shutting down the engine. That did not happen until later in the decision-
making process. After the flight had transitioned to the departure controller and had climbed to 5,000 feet, the crew reported that they had not shut down the engine. Instead, they had throttled it back and were performing the required checks.
The following comments from the flight crew have generated various opinions among some readers. The crew said, “We have now shut down the number-two engine and will consult [the] company to see what they want us to do.” After several more minutes, the crew reported to ATC that they needed about 10 minutes to contact company to see if they should return to Los Angeles or continue the flight.
To me, those words clearly indicate that this crew was turning over at least some of the decision-making to whoever was on the other end of that communicating equipment.
Today our aircraft have communication equipment that allows the crew to maintain contact with their company from almost anywhere in the world, and that has resulted in some unintended consequences. While I was on the NTSB, Alaska Airlines had a tragedy involving an MD-83. The flight crew experienced a problem and communicated with their headquarters, including maintenance. While the crew was performing this in-flight troubleshooting, the airplane overflew many suitable airfields before crashing into the Pacific Ocean.
Humans tend to exclude all other possibilities once we’ve made up our minds that we know the cause of an event. The British Airways flight crew reported early in this event that they believed it was an engine surge, a normally benign event. However, they also stated that they observed the engine temperature climb into the red (over-temperature) zone, a clear indication of permanent damage to internal parts. Add to this the fact that after the flight crew had throttled back the engine, they were unable to advance the thrust lever, as this resulted in an almost immediate surge noise. A subsequent attempt at a higher airspeed had the same effect.
These events should have raised grave concerns from the flight crew about the event being something much more serious than a routine engine surge. Although the flight crew could not determine with available instruments the internal condition of the engine, maintenance later discovered the turbine section destroyed from over-temperature.
It is the many unknowns that made the decision to continue this flight a bad one. As airmen flying in commercial service we have an obligation to operate to the highest levels of safety, and to continue a flight with so many unexplained issues fails to meet that standard.
Like many others, I believe that a flight with one engine shut down can be conducted safely under certain conditions. For example, if an aircraft is flying along in cruise and the EGT climbs slowly to the point of reaching over-temperature, and if this engine must be throttled back or shut down but all other systems and engines are normal, then it would be appropriate to continue.
There are other possible scenarios that would be similar, but all could be classified as low-risk. I believe these types of scenario are what British Airways had in mind when it included this procedure in the flight operations manual. However, sometimes procedures get stretched beyond the original intent.
Some of you have commented to me about the FAA’s filing a violation complaint against the flight crew. From my research, the agency took action only against British Airways, not the flight crew. The FAA imposed the maximum fine allowed under U.S. law. This was settled with British Airways’ agreeing to change its procedures for flights operating in U.S. airspace.
When conducting an investigation into an unusual event, it is important to get
all the facts you can before reaching any conclusions. In this case some of the facts were slow to be released. However, it is clear to me that this flight crew allowed their company’s flight control unit to have more influence on the required decision-making than it should have had.