TMetzinger
Final Approach
Here's a hypothetical situation.
You're flying along in IMC enroute on a long cross country. You have a complete loss of engine power (on all engines). Perhaps you had bad fuel, perhaps you were stupid and ran out, perhaps you had a leak - doesn't matter.
Given:
I think I'd put out the flaps and the gear and trim for 1.2 Vs0.
Best glide gives maximum forward distance for vertical distance lost, but is not a super slow speed, and I don't know if I'll get enough warning to "land" if I'm in IMC all the way down.
Minimum sink is similar - I'm not sure it results in mimimum energy on touchdown.
Stall speed seems to me to be the minimum energy state, but it's also the knife edge of controllability. So I think I still need a small cushion above it.
But, perhaps 1.1 Vs0 would be sufficient.
You're flying along in IMC enroute on a long cross country. You have a complete loss of engine power (on all engines). Perhaps you had bad fuel, perhaps you were stupid and ran out, perhaps you had a leak - doesn't matter.
Given:
- You know where you are, and you're out of gliding range for any airport.
- You don't know how low the clouds are in this phase - again, you're far out of useful range of any reporting station.
- You have the MEFs on your chart for terrain, but no detailed knowledge, so you don't know where ground level is.
- Essentially, you may return to earth without ever seeing anything but clouds.
- Your gyros are ok - either you're getting enough suction from windmilling, or you've got electrics - but you CAN keep the wings level.
- Under control
- With wings level
- At the slowest speed possible while meeting the first two goals
I think I'd put out the flaps and the gear and trim for 1.2 Vs0.
Best glide gives maximum forward distance for vertical distance lost, but is not a super slow speed, and I don't know if I'll get enough warning to "land" if I'm in IMC all the way down.
Minimum sink is similar - I'm not sure it results in mimimum energy on touchdown.
Stall speed seems to me to be the minimum energy state, but it's also the knife edge of controllability. So I think I still need a small cushion above it.
But, perhaps 1.1 Vs0 would be sufficient.