It looks as if the USA and UK will agree to differ on the one-engine-shutdown case. After all, neither party is wrong
After the loud debate about what constitutes operational best practice when the crew of a four-engined aircraft has to shut down one of the powerplants, things have gone very quiet.
Two years ago a British Airways Boeing 747-400 crew had to shut the No 2 engine down when it surged just after take-off from Los Angeles bound for London. After the crew had revised the performance criteria for the three-engine case and liaised with the operations department, they elected to continue and finally landed in the UK. The Federal Aviation Administration didn't like this decision, although it complied with the airline's operating criteria and those of the UK Civil Aviation Authority. Some 18 months later the FAA was about to put the case before a US court on the grounds that the crew had continued flight in an "unairworthy aircraft", but at the last minute it withdrew the case.
The UK Air Accidents Investigation Branch investigated the incident and did not question the operational decision to proceed. It did, however, recommend that the FAA and the CAA should harmonise their advice so as to "provide clear guidance for the operators". The FAA has acknowledged the recommendation, but has yet to respond to it, and the CAA has accepted it, but no transatlantic meeting of minds has taken place.
This is no great tragedy. Both sides have reviewed the case in huge detail, and both have reached tenable positions on safe practice even if they differ on best practice. The FAA says, in a letter explaining its legal climbdown, that BA had changed its operational procedures for the three-engine case. But it has not. It seems BA, chastened by the press and passenger perception of the decision to proceed on such a long flight with one engine shut down, told the FAA it recognised it would have to take the "perception factor" into consideration in future cases like this. The admission by BA's operations purists that there is a real world out there - and they can't afford to ignore it - looks as if it provided the FAA with the let-out clause it needed. Meanwhile the FAA, as it develops with US carriers the practices they will adopt under its new rules for operating big twins further than ever away from diversion airports, would do well to take the same "perception factor" into account for the day when a crew decides to continue a very long distance on a single engine, rather than three.
Source: Flight International
