Lukla - landing at altitude

[Tozzifan 7]

Hello,

 

although I smoothly managed my first landing in VNLK, setting the usual flaps 4 and speed around 70 knots as for short runways, I guess that in less dense air flaps setting and speed should be managed differently

 

how do the TwinOtter pilots manage landing at altitude in real life?

 

any web reference, please?

 

thanks

[Herman 1591]

The indicated airspeed (IAS) you fly at sea level for a given weight and flap setting (with everything else such as turbulence constant) is what you use at higher altitude, even Lukla. Indicated stall speed for a given loading and configuration is constant regardless of altitude (density altitude, actually), therefore, so is approach IAS. However, while you'd use the same IAS at Lukla as at sea level, the true airspeed (TAS) is considerably higher. TAS is directly related to ground speed, in fact they're essentially the same in a no-wind situation. So the ground speed and and landing distance required at Lukla is more than at sea level.

 

See the FAA Pilot's Handbook of Aeronautical Knowledge (link here), since you requested a reference. Chapter 11 is the most relevant. You might also find the FAA's Airplane Flying Handbook helpful too (link here). For other handbooks that add to this topic, see the list at this link.

 

IRL, in a transport category aircraft, one might use a different flap setting in an approach with obstacles in the departure path than without, especially in the event of an engine failure, to facilitate a go-around. But that's probably outside what I think you're asking about.

 

 

[mopperle 4162]

And iy you want to learn more about the Twotter, watch this video series, made  by a Mark Hurst (user here in the forum):

 

The content of thois video is also available on Kindle:
https://www.amazon.co.uk/Twin-Otter-Extended-Inside-Out-ebook/dp/B01AZT76MA/

 

[Herman 1591]

Because we believe this topic has been answered we have closed it. If you have any more questions feel free to open a new topic.