What is the zero-fuel range of the common training types e.g. C150, C152, PA28-140, PA28-161, PA28-181?
At sea level, ISA, TAS=IAS
Fair enough….I guess the implicit assumption in my response was “for a given %HP”…. Ass-u-me! :embarrassed icon:
max TAS is at sea level….I think he means IAS
At sea level, ISA, TAS=IAS 
Actually it may be true that max speed in a non turbo aircraft is reached at sea level, but at a high cost in fuel and certainly at a power setting well above 75%.
I recall seeing 165kt IAS in my TB20 at about 1000ft, full-bore i.e. about 23 GPH. That is close to 100% of max rated power. That’s the same as the above TAS at FL070.
Peter, or anyone else (probably most) that knows, what exactly is the vs <60kt limit? I have seen it mentioned from time to time and notice a lot of SE aircraft with a vs of 59kts etc but I am unsure the reason. What happens if Vs is over 60? I have a gap in my knowledge here.
Det er akkurat riktig!
Edit: sorry my spellchecker refuses to allow anything but English!
Reference please.
Especially if the aircraft can barely even reach 8000ft…
It sometimes surprises me that we live on the same continent I have said it before, and I will say it again. I thought this site was Euro GA, not UK GA. Not that it bothers me. Coming from Norway I am used to being a “minority” wherever I go (virtually or real).
Van’s, Sonex, Glasair and Lancair all advertise cruising performance at 8000’. Together that is at least 60-70% of the experimental market with tens of thousands of aircraft flying, and almost every single one of those aircraft can outclimb, outrun and fly at higher alt than a TB20GT or any other “span can” The Xenos being a motorglider, doesn’t even have a ceiling. Even the Lancair Legacy RG-550 (Conti IO-550) and the Glasair III (IO-540) is advertised with 240 KTAS at 8000’ and 242 KTAS at 8000’ respectively.
@Mark 1 said max TAS is at sea level….I think he means IAS…
This from my POH: (sorry, can’t get it to upload..)
Anyway max TAS is at 8000’….171kts at Max Wt…75% power 12.5GPH Best Power 55dF ROP
I have two data points from the flight just now, FL070 +8C full throttle:
Best power (130F ROP):
18.5 GPH TAS 164
MP 22.7" 2575 RPM
IAS 147
This is the absolute fastest the TB20 will go at FL070 and +8C.
Best economy (peak EGT):
11.5 GPH TAS 155
MP 22.7" 2400 RPM
IAS 139
Go figure! Guess which figure a salesman would use… and will he mention the fuel flow? No.
Different aircraft tend to fly at different altitudes. You wouldn’t advertise an A320 by its speed at 8000ft and you wouldn’t advertise a C172 by its speed at 12000ft.
As to the Cirrus SR22T or Piper PA46 argument, these are touring aircraft designed for FL200+. If you don’t intend to fly them there, then you’re not really the target audience.
NA piston aircraft perform best at 8000ft which is why this is a very sensible altitude to use in comparisons. All POHs assume ISA (and usually give another set of values for above and below ISA) so TAS is the best way to compare aircraft performance.
Peter’s argument very much applies to how e.g. the T182T (the turbo fixed gear C182 that Cessna stopped producing last year) is marketed. It has a very draggy airframe but the TIO-540 makes it climb to FL200 and up there it is almost as fast as the TR182 (retractable gear) because the air is so thin that dragging the gear comes at a very small penalty. Same goes for the SR22T — at FL250 the fixed gear has a negligible influence. So the T182T is marketed with its high speed at a level it is rarely ever used while it is at least 20kt slower at normal cruising levels than its RG sibling.
