When reading a/c specifications/performance's what do people think the speeds listed are? Indicated or groundspeeds?
I'm just trying to guestimate abort/recall points on a route map see.....
Speed listings
Re: Speed listings
IIS (indicated air speed). Ground speed will vary immensely with the wind direction relevant to the aircraft. An aircraft flying at 200kts IIS into a 40kts head wind at altitude will cover the ground at 160kts, if a tail wind, 240kts. There may only be 25kts of wind at ground level!
"The purpose of life’s journey is not to arrive at the grave with a well-preserved body, but rather to Slide in Sideways, completely used up, yelling and screaming, what a ride!" anon.
Re: Speed listings
Given the physics of the atmosphere, indicated airspeed differs markedly from true airspeed, and groundspeed will change on any given flight depending on the winds aloft, which can change depending on altitude as well. So without knowing all of those variables, it's going to be tough...
I guess it depends on what your source is. Pilots fly aeroplanes by reference to indicated airspeed, so documents produced for them (pilot's notes etc) will be reference IAS because that's what they see in front of them. All else being equal, an aeroplane always stalls (for example) showing 'x' knots on the airspeed indicator regardless of its height or the air pressure on a particular day (essentially because the wings are working in the same air as the pitot head). Meanwhile the navigators ultimately navigate aeroplanes by reference to groundspeed, so documents for their use will be different again, and they calculate (or, these days, look at a GPS!) the groundspeed multiple times on any given flight. Neither figure - IAS or GS - on its own is of much use for giving an accurate number for 'how far can this aeroplane fly' without knowing more of the story though.
That probably didn't help any...
I guess it depends on what your source is. Pilots fly aeroplanes by reference to indicated airspeed, so documents produced for them (pilot's notes etc) will be reference IAS because that's what they see in front of them. All else being equal, an aeroplane always stalls (for example) showing 'x' knots on the airspeed indicator regardless of its height or the air pressure on a particular day (essentially because the wings are working in the same air as the pitot head). Meanwhile the navigators ultimately navigate aeroplanes by reference to groundspeed, so documents for their use will be different again, and they calculate (or, these days, look at a GPS!) the groundspeed multiple times on any given flight. Neither figure - IAS or GS - on its own is of much use for giving an accurate number for 'how far can this aeroplane fly' without knowing more of the story though.
That probably didn't help any...
Remembering the crew of 467 Sqn Lancaster LM475 PO-B Jan-May 1944
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Re: Speed listings
The question was about published figures, that would have been IIS. Kookabat it quite right in that without knowing all the variables on that particular night, you will never be able to position your aircraft accurately. I have landed vertically at the start of a runway because the headwind equaled my airspeed on finals, therefore no groundspeed. I was already very close to VNE too!!!
"The purpose of life’s journey is not to arrive at the grave with a well-preserved body, but rather to Slide in Sideways, completely used up, yelling and screaming, what a ride!" anon.
Re: Speed listings
roger g/s-ias, think I was getting confuddled about ias/tas and pressure differences affecting things etc, thanks to a certain forum member I've got alot of the met gen to help me in my efforts, no name mentioning here (ALAN) 
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