Which do I read please, ground speed or airspeed

Ground speed while taxiing. Airspeed on takeoff, landing, and during flight


Thanks😀! Because I always fly Miami to Tampa and I fly at 0.75mach

Use ground speed to calculate your V/S when descending also: GSx5.

Thanks what’s a good ground speed for 28,000ft

That really depends on what type of aircraft you are flying

Boeing 77W

At FL280 use as reference the Mach speed. The 777 has cruise Mach of 0.84.

well, what do you mean?

with regard to a descend calculation?


to stay in the air, airspeed is the one !

just think of the coffin corner

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@Temidayo_Ekundayo… Max Sez; Temison, get a free copy of the “Pilots Handbook of Aeronautic Knowledge” from faa.com, it’s a Pilots Bible.Then download the “Pilots Operating Handbook” (POH) for the type yr flying. It has all the V’s. Me thinks Clipper hit the nail on the head. It’s all about “Energy”!

Said copy can be found OTI in the FAA page here: http://www.faa.gov/regulations_policies/handbooks_manuals/aviation/pilot_handbook/

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Erm, actually, if you use a default airspeed of 400kts, it will indicate about 500kts or higher which is about Mach 0.90 or more, so, airspeed doesn’t count due to the winds

I just meant in general, … with regard to the question which value should be observed to stay in the air.