737 300/400 engine out target speed
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737 300/400 engine out target speed
Hi there!!!
Yesterday after leveling off in FL 320 I checked CRZ page in the FMC to note engine out target speed,max altitude etc.
The intresting thing was that engine out speed was 196 knots which made me wondering whether the number was correct...
As we all know this speed is calculated by the FMC upon actual gross weight and it represents best airspeed(climb or DRIFTDOWN) only in CLEAN configuration.
Engine out drift down procedure as decribed in Boeing's flight crew training manual states that before a drift down commences speed should decay to engine out target speed which in our case should be flown with flaps 1(or no?).
Anyway as I find it a litlle strange to make a drift with flaps extended(even in position 1)and also because FMC computes this speed for clean configuration only, as told before could it be drifting down with flaps up and still 196 knots?!?!?!
Comments are more than welcome!
Happy landings
Yesterday after leveling off in FL 320 I checked CRZ page in the FMC to note engine out target speed,max altitude etc.
The intresting thing was that engine out speed was 196 knots which made me wondering whether the number was correct...
As we all know this speed is calculated by the FMC upon actual gross weight and it represents best airspeed(climb or DRIFTDOWN) only in CLEAN configuration.
Engine out drift down procedure as decribed in Boeing's flight crew training manual states that before a drift down commences speed should decay to engine out target speed which in our case should be flown with flaps 1(or no?).
Anyway as I find it a litlle strange to make a drift with flaps extended(even in position 1)and also because FMC computes this speed for clean configuration only, as told before could it be drifting down with flaps up and still 196 knots?!?!?!
Comments are more than welcome!
Happy landings
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196 knots clean... The 210 knot min clean speed no longer applies once you are single engine. In case you can't get your hands on the FMC to get the speed out in the heat of the moment, drift down speed is approx green dot speed on the speed tape.
Its kinda similar on the single engine flap 1 go around, where you climb out at Vref (flap15)+5, which is more often than not in the yellow buffer area on the speed tape. Its acceptable....
Its kinda similar on the single engine flap 1 go around, where you climb out at Vref (flap15)+5, which is more often than not in the yellow buffer area on the speed tape. Its acceptable....
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This is similar to the engine failure on Takeoff scenario, where the optimum speed does not guarantee what we accept as normal manoeuvre protection, and is limited to 15° bank angle.
The B737 is not unique in this respect, it occurs on many aircraft. In Ops Manuals that I've written I've included that, in turbulent conditions, speed increase to normal manoeuvering should be considered if en-route terrain is not a problem. In doing so, a faster and steeper descent must be accepted, with a somewhat lower level-off altitude following Drift-Down.
Regards,
Old Smokey
The B737 is not unique in this respect, it occurs on many aircraft. In Ops Manuals that I've written I've included that, in turbulent conditions, speed increase to normal manoeuvering should be considered if en-route terrain is not a problem. In doing so, a faster and steeper descent must be accepted, with a somewhat lower level-off altitude following Drift-Down.
Regards,
Old Smokey
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seat1Aplease
you re dead right about the 20000 ft limitation for flaps extension,I thing that clarifies everything!!
Stupid not to remember it in the first place..
Thanx also to the other guys for their help!!
you re dead right about the 20000 ft limitation for flaps extension,I thing that clarifies everything!!
Stupid not to remember it in the first place..
Thanx also to the other guys for their help!!
