Do you really have enough fuel? / B737 performance question.

[john_tullamarine]

Two points.

(a) the manual data to which Blip refers are, presumably, contained in company performance manuals which will have been produced from the relevant Boeing data ? If so, then the pilot group ought to take the matter up with management if the pilot group believes that the status quo is not quite the way to go.

I have file data for 200/300/400, which may be out of date as I have been away from 737s for a while now.

However the point is .. your flight standards management people will have access to the relevant current data and have only to direct the performance engineering people as to company policy in respect of this failure and that.

I have seen some policies which make me shiver but that is the way it goes provided that the regulatory requirements in the relevant country are met as a minimum standard. I can recall one colleague, who was working for a major airline at the time, telling me that they didn't worry about any takeoff failures other than V1 cases ... certainly not the approach that I would take in performance scheduling work where there are obstacle considerations ... and the failure might well occur before the critical turn ?

(b) BOAC's point is very valid. Certification generally is based on one major problem. Normal practice is to consider subsequent problems which have a reasonably likely probability.

While I appreciate that it may not be easy in a deregulated and weak (or no) union environment sometimes the captain has to earn his money by making prudent risk-based assessments before flight even if that flies in the face of management pressures... easy to say ... yes .. but that is the way things are.

I can recall the odd occasion where well intentioned pilots tried too hard to follow the company preferred options and ended up in uncomfortable positions while they sweated ... watching the fuel gauge tick down towards zero... and the occasional case where the aircraft managed to get in .. and the engines failed on the rollout. I am sure that we all know of such things.

It is not just a matter of adopting an overly conservative policy in the real world .. a good way to go broke quickly. Clearly the two extremes are to have full tanks all the time and patently not enough fuel for the flight. Often a prudent and reasonable fuel load is somewhere in the middle. It must remain a decision process balancing reasonable corporate goals against sensible risk-mitigating flight planning. It is, of course, comforting to meet the regulatory requirements as well.

Granted it can be a tough time for the captain but, if one seeks an always easy life, then perhaps the life of the bank clerk may be the way to go .... and, very occasionally, things go totally topsy turvy once the aircraft is launched and the outcome may not have a rosy ending.