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Re: Limit to 120 KCAS at sea level only with custom EMS - still an LSA?
Posted: Tue May 05, 2020 7:04 am
by MrMorden
fatsportpilot wrote:MrMorden wrote:The 120kt CAS limit is a limit for *manufacturers* to design to, not for pilots to abide by. Once an airplane is accepted by the FAA as an LSA, you as a pilot can wring whatever performance out of it that you can. If the aircraft type regularly and easily exceeds LSA performance limits, that's a problem between the FAA and the manufacturer, and the pilot need not be concerned at all (unless the FAA revokes the LSA designation for all existing airframes of that type...but then you have a pretty nice lawsuit against the manufacturer).
I'm pretty sure sport pilots can't modify an E-LSA to exceed speed limitations that the pilot also has to obey. Just like a sport pilot can't climb above 10,000 MSL even if the plane has a higher service ceiling.
In the case of modifications they are acting as an operator or mechanic, not a pilot. But I was taking about factory airplanes, not illegal modifications.
My CTSW can regularly hit 127kt, both TAS and indicated. Is that above 120kt CAS? Who knows? But if it is, it's simply not my problem. It's between Flight Design and the FAA.
Re: Limit to 120 KCAS at sea level only with custom EMS - still an LSA?
Posted: Tue May 05, 2020 7:28 am
by drseti
MrMorden wrote:fatsportpilot wrote:MrMorden wrote:My CTSW can regularly hit 127kt, both TAS and indicated. Is that above 120kt CAS?
Probably not, at sea level, standard atmosphere, and max continuous power (which is, after all, how Vh is defined).
Re: Limit to 120 KCAS at sea level only with custom EMS - still an LSA?
Posted: Tue May 05, 2020 7:33 am
by MrMorden
drseti wrote:MrMorden wrote:fatsportpilot wrote:
Probably not, at sea level, standard atmosphere, and max continuous power (which is, after all, how Vh is defined).
I have hit 127kt at 1500ft MSL on a 70°F day at 5500rpm. I have one of the faster CTs around. I don't know what that translates to CAS, but it might be greater than 120kt CAS. My only point is it doesn't matter.
Re: Limit to 120 KCAS at sea level only with custom EMS - still an LSA?
Posted: Tue May 05, 2020 7:41 am
by drseti
Andy, unless you try 5500 RPM at exactly sea level, 29.92 inches of mercury, temperature15 C, and zero relative humidity, at max gross weight, with your pitot tube oriented exactly into the relative wind, you have no idea what your Vh is. But, you're right, that's the manufacturer's problem, not the pilot's.
Re: Limit to 120 KCAS at sea level only with custom EMS - still an LSA?
Posted: Tue May 05, 2020 9:37 am
by MrMorden
drseti wrote:Andy, unless you try 5500 RPM at exactly sea level, 29.92 inches of mercury, temperature15 C, and zero relative humidity, at max gross weight, with your pitot tube oriented exactly into the relative wind, you have no idea what your Vh is. But, you're right, that's the manufacturer's problem, not the pilot's.
All true.