Sport Pilot Speed Restriction

Hey Robert, The 138 mph limit is "maximum sustained cruise at sea level". This is how I understand it. For example, say you have a Sonex with a 2200 Jabiru and max cruise rpm of 3100. Your max cruise at sea level is 138 mph but at 6000 feet true air speed will be much higher. The 120 knot is not an absolute speed limit and there's no way to enforce such a limit. Catch a good tailwind and you would be in violation. Most LSA's cruise at well below 138 mph but some slick ones, like the Sonex, have the potential of busting the speed limit. The LSA speed limit is more of an "honor system, self policeing ",  deal because, in my opinion, it will be impossible to enforce. James Thomas 

Let's simplify this.  It's not  an absolute speed limit.  It's a way of limiting the speed of the aircraft using a fairly straightforward measure, VH (by copy to Hal, do we have subscript ability so we can do V-speeds properly?).  There is no limit on the sport pilot, other than the endorsement requirement for flying something with a VH greater than 87  - look through subpart J of the FAR's and you won't find anything else.  So, no, you haven't violated anything if you descend at 125 KIAS in your Remos, CTSW, or whatever as long as you don't exceed the aircraft limitations.

Thanks for the info to both of you!  I figured as much, but I just wanted a 2nd opinion.  Enforcement will definitely be difficult, but if it is an aircraft limitation (and the aircraft is in fact a legit LSA) then it is a moot point. A few folks I fly with say they think it is an indicated Speed limit (so a tailwind wouldn't be a factor).

Well, it's true airspeed, which is calibrated airspeed corrected for temperature and pressure, so if you your ground speed is higher or lower due to winds, so be it.  But I think you missed my main point:  VH is the maximum speed at which the plane will fly with maximum continuous power.  For example, after replacing the prop on a CTSW, we flew the thing full out at 2200 feet in the pattern and it worked out to 127 knots TAS - the mechanic and I landed and tweaked the angle on the ground adjustable prop to dial back the speed.  After a couple of flights, we got the speed down to where it was supposed to be. 

Having done that, the plane's red line was far higher (I forget what it is - it's been a while since I've flown it).  I've flown the plane faster than 120 in powered descents, which is perfectly legal, as long as I didn't exceed the aircraft's flap or airframe limitations.  That's what I was refering to when I mentioned the aircraft's limitations.

Clarification:

It is 120Kt CAS, not IAS or TAS.

LSA cannot exceed 120K CAS at sea level in standard atmospheric conditions at maximum CONTINUOUS RATED horsepower.  Technically, that means if your plane's maximum continuous rated horsepower is at 2900 rpm at sea level, but you don't mind beating on it a little by running it at 3100 rpm (at sea level, which will probably never happen),  you can.  If the extra 200 rpm causes you to be "cruising" at more than 120Kts, you're still "legal" (technically).

You're right - I don't know how I got hung up on TAS.  Anyhoo, the important thing is that if you exceed VH because you're descending with power, or whatever, as long as you're not exceeding the airframe limitations, you're OK.

In the case of Vh, which is at sea level under standard conditions, CAS is exactly the same at TAS. 

IAS and CAS decrease as density altitude increases from sea level standard conditions, while TAS increases at same power setting. Same power setting at higher density altitudes requires more throttle and more rpm with a fixed pitch prop, which is another subject altogether.

Actually the regs say, CAS at sea level at the manufacturer's highest recommended continuous RPM.  So if Jab wants to say the 3300 is 2750 they can.  Of course people run em at 3300 all day long.  Problem is, once you get in that range your fuel consumption climbs like the Space Shuttle.  Can your speed in the air be monitored?  Of course not.  Its a building limitation that is part of the SLSA certification process.

I know all that.  I'm just annoyed that I went with the wrong term when quoting the reg.

You can not perform aerobatics as a sport pilot so that should not be an issue anyway.

Huh?  There is absolutely nothing in the regs that say a Sport Pilot can't do aerobatics.

Most LSA's aren't built to take it and aren't cleared to be flown aerobatically, but that's not the pilot's fault.  If the plane can, he can.

Cool, is there an endorsement for that?

Sorry to thread hijack.

Other than one for spin training, I haven't found one.  I hunted around the FAA site and found a circular on aerobatics from 1977 which seems to still be in effect - here.   It confirms that there isn't an official aerobatic endorsement, though there are flight schools that will certify one as being trained for it.  I imagine no insurance company would ever pay if a pilot wrecked while doing aerobatics and wasn't certified by someone reputable as qualified.

Remember, though, that the definition of aerobatics is any manuever not required for normal flight.

Technically speaking, S turns around a road is an aerobatic stunt, as banking from one 180 turn into another in the other direction isn't quite normal.  It's a good test of proficiency, though.

But let's say one's plane can handle a Chandell without any risk of falling apart.  Nothing to say one can't perform the manuever so long as the minimum altitude is maintained.

The limitation is on the aircraft.  They have to be rated for +6/-3 G's to be considered aerobatic.  Performing a split S in a utility aircraft rated at 4.4/-1.76 G's might not be such a good idea.  There is no reset button in real life.

Haven't logged into this thread in a while - good discussion. I had a conversation with someone about LSA Aerobatics. There aren't many out there, but there are some people doing it and some aircraft rated for it.

The Swick T comes to mind as one option (they flew it at Oshkosh 2010)

Another is a brand new LSA being produced by FK called the comet. Rumor has it that it is soon to be available in the states. Looks like a neat aircraft and will be very capable for aerobatics.  There is also a 'limited' version which adds some additional capability.  Cool stuff!

http://www.fk-lightplanes.com/html/fk12_comet.html

So any plane rated for +6/-3 G's is considered to be capable of full Aerobatic maneuvers?

I've been trying to figure out for some time what was needed for a plane to be capable of those kinds of flight maneuvers for a while now.  Am I correct?

Hi guys-  I am getting a little uncomfortable with where this thread is heading.  As far as aerobatic aircraft certification is concerned, it is not simply a matter of G-limits.  Aircraft in Acrobatic category also have to have demonstrable safe and predictable spin-recovery behavior, and the manufacturer will specify what maneuvers can be done safely.

   For instance, the Decathlon is certified in the Acrobatic category, however, tailslides are not approved, you could potentially damage the aircraft trying to do one.

   Some existing "grandfathered" types like the clipped Cub are very capable aerobatic airplanes and fall into Sport Pilot eligibility. That does not mean they can do anything, but they will recover from a botched maneuver safely.  Current manufactured LSAs (which seem to be proliferating rapidly) do not have an Aerobatic category of certification, basically the manufacturer states which maneuvers are approved based on whatever criteria they are comfortable with.  For instance, the Cessna 162 Skycatcher is certified as an LSA but is not approved for spins (apparently with good reason).

   If you want to do aerobatics as a Sport Pilot, there is absolutely nothing stopping you, you are subject to the same restrictions as any higher-level certified pilot.  There is no specific aerobatic certification or endorsement.  However, just because an LSA-compliant airplane has a +6/-3G limit, it may not be safe for aerobatics due to unpredictable spin or loss-of-control behavior.

   My bottom line on this- if you want to do aerobatics as a Sport (or any other) Pilot, get some formal training from a qualified instructor (the IAC is a good place to start, check their website through EAA), make sure the airplane is truly safe to fly aerobatics, and follow the safety rules (airspace,altitude, parachutes).  DON'T try to teach yourself, DON'T do aerobatics in non-aerobatic airplanes, and make sure you have had some good spin training. 

    Then (and only then) go out and have fun with it!!        Cheers, Tony 

"My bottom line on this- if you want to do aerobatics as a Sport (or any other) Pilot, get some formal training from a qualified instructor (the IAC is a good place to start, check their website through EAA), make sure the airplane is truly safe to fly aerobatics, and follow the safety rules (airspace,altitude, parachutes).  DON'T try to teach yourself, DON'T do aerobatics in non-aerobatic airplanes, and make sure you have had some good spin training." 

Concur!

While I have zero desire to do aerobatics, part of my personal syllabus is to get spin training - simply because I think it would be prudent to experience my first spin under the guiding hand of an experienced CFI rather than under duress.  Not that I anticipate entering into spins, mind you....

Eventually I'd like to get aerobatic training as well.  Wing overs and barrel rolls are for flight sims and professionals, IMHO, but the skills in precision flying gained would be well worth the time and money, as they'd translate into so many areas of normal flight.

The thread mutated simply because an assumption of restrictions on Sport Pilots was corrected.  I understand the license is relatively new and so there is a lot of confusion and misinformation out there.  The other day a fellow was telling me that he wouldn't want to be a Sport Pilot because he likes to fly cross country!  A decent guy, he was just ignorant of what the actual restrictions are, and came away appreciative of the rating once explained to him.  Light, slow, uncomplicated two seater aircraft flying daytime VFR within US boundaries (okay, and the Bahamas) are the only limitations.  Additional endorsements for controlled airspace, tailwheel, and sets of aircraft.

While I do want to do aerobatics someday.  I am not anywhere near foolish enough to attempt those maneuvers without getting proper training.  I was simply looking for clarification about what kind of LSA's have the needed characteristics for such flight.  After all, I'm looking to buy an aircraft and want to make sure it is capable of doing as much as I want to do.

I'd plug into the IAC community - they'd definately know which planes fit, and moreover the A&P's to do pre-buy inspections on any plane one might plan to do aerobatics in.  I can just hear the heartbreak of "Well, son, it's gooder enough if you're goin' from here to yonder, but I wouldn't do much more than that until you get a better weld on station 76, put in better control lines, replace the pulley at station 100, and get you some better anchors for those flying wires."

What we really need to do is get a Georgia Tech class to design a fully aerobatic LSA for us that can be built for 25K.  Heck, if they scaled a Pitts down that would be great.