View Full Version : Climb Limit Weights
TwinJock
3rd Oct 2008, 15:53
Need some info and explanation on the difference between the Approach Climb Performance and Landing Climb Performance on a twin!
Thkx:ok:
Old Smokey
3rd Oct 2008, 20:40
The "Approach Climb" is essentially for the configuration that you would set the aircraft to if a missed approach was carried out during approach, i.e. Gear UP and the Flaps retracted to the "Go-Around" setting, typically a setting routinely used for Takeoff. With OEI, the minimum Gross Gradient is 2.1% (Note that PANS-OPS minimum obstacle-clear gradient is 2.5%, be careful!)
The "Landing Climb" is with ALL engines operating in the Landing Configuration, i.e. Gear DOWN" and Flaps left at the Landing Flap setting. Minimum required gradient is 3.2%.
In Short, Approach Climb is intended to cover you for a 1 Engine Inoperative Missed Approach, and Landing Climb for the All engines missed approach. (There's a bit more to it than that, but that's the basics).
Regards,
Old Smokey
TwinJock
4th Oct 2008, 05:20
Thanks Smokey!
Does it imply that the Approach Climb Performance is always more limiting than Landing Climb Performance on a twin?
BelArgUSA
4th Oct 2008, 05:45
Sorry - old fart here - but yes, I remember the approach climb is always the limiting factor.
This with 2, 3 or 4 motors. I did not study requirements for planes with 5...
Balked landing climb is not limiting.
xxx
:)
Happy contrails
Old Smokey
4th Oct 2008, 08:19
BelArgUSA got it right, no further comment necessary :ok:
(Mind you, the law of "Stating things categorically" dictates that somewhere "out there", there's a weird aircraft where the Landing Climb MIGHT be more limiting, but like my "old fart" colleague, I can't think of any:confused:
Regards,
Old Smokey
Mad (Flt) Scientist
4th Oct 2008, 14:18
How about a fixed UC aircraft, where both approach climb and landing climb have the drag of the UC? Then it depends if the drag saved by retracting to the approach flaps is more than the power lost by a single engine loss?
BelArgUSA, check your notes again for the B747 Classic.... the landing climb becomes more limiting at high altitudes and temperatures..... At least with the RB211......
How many days left?
Mutt