Mooney_Driver wrote:
Obviously balanced field lenght is a concept which not many SEP pilots even know about… and which some MEP’s should remember.
BFL in an MEP is different from the way it is normally looked at. In general, there is no accelerate-go option ie there is no scenario where after an engine failure on takeoff below V1 you would continue into the air. As Timothy says, in an MEP it is essentially about can you stop on the runway if an engine fails before you rotate. Not really BFL to be honest.
To be fair it is the usual way to which it is referred – if you google most twins you will find the bfl stated somewhere in the ps.
Fuji_Abound wrote:
To be fair it is the usual way to which it is referred – if you google most twins you will find the bfl stated somewhere in the ps
Sure, but the whole idea of BFL is that ASD=AGD. That is what balanced means.
Try finding an MEP flight manual that allows you to calculate a balanced field length.
Which has sort of been done before.
It’s different in a Perf A operation. That must be calculated to the Nth degree. Fuel dumping will be part of that calculation.
QuoteThat means that the chances of a total engine failure from hero to zero at that split second of 77kts is really very unlikely. If I got bad indications at 77kts (say the loss of a cylinder, rough running and a drop in RPM) I would take it into the air, get the gear up, blue line and then shut down. We are only talking a few seconds.
From the previous discussion.
It really isn’t a linear decision in an MEP. Last week, the shortest runway I operated from was a mere 4700m and the OAT was about 40 Celsius. If I had an engine failure at 100-200ft on climb out I would most certainly of retarded both levers and landed ahead; climbing away at Vyse, completing a circuit and landing would have been interesting. At places like Shoreham, you’re committed to crashing way before Vtoss. In fact, in this scenario think like a SEP.
All MEPs are Performance B at best but they do include ASDA charts. This is a performance calculation requirement in the US. Balanced field describes runway dimension characteristics (TODA=ASDA). There are separate charts for TODA and ASDA. The CAA used to provide public transport safety factor ASDA charts for some older MEP types. This chart is unfactored.
Timothy / Dave so I am a bit confused now with all the theoretical discussion! We have added something around our 10% margin, know there isnt time to stop at rotation, and disaster, catastrophic failure just after rotation in lets say an Aztec. Two scenarios depending on whether it is the left or right the gear will / wont retract, what are your solutions? Timothy and by all means please contrast this with your earlier post referred above with a failure at 77Kts.
