Can my RV8 be flown under the new Sport Pilot rules? No medical and only a drivers license? I have flying under Basic Med rules. If so, I might not need to sell my plane using only the Sport Rules.
Can my RV8 be flown under the new Sport Pilot rules? No medical and only a drivers license? I have flying under Basic Med rules. If so, I might not need to sell my plane using only the Sport Rules.
Mel, thanks for your reply. Vans spec the RV 8 stall speed of 58 mph. The proposed speed is 54 knots. My AS indicates 62 mph and that is probably off with instrument error. That should work using Vans numbers.
Several years ago I communicated with Van’s about the published max gross weight (1800 pounds) stall speeds of the RV-8 when I was looking at its maneuvering speed.
Van’s verified that the RV-8's flaps down stall speed (Vso) is approximately 58 MIAS/50.4 KIAS, as shown on the RV-8's performance page.
They also verified that the flaps up, clean stall speed (Vs1) is approximately 64 MIAS/55.6 KIAS, which is shown on their “Airspeed Indicator Markings by Model” chart as the bottom of the green arc.
But again, those are Indicated Airspeed and the new MOSAIC NPRM's Vs1 stall speed requirement is stated in Calibrated Airspeed (Vs1=62 MCAS/54 KCAS). So the instrument and position error at those low speeds needs to be measured to find out what the RV-8's stall speeds are in CAS for a valid comparison.
I have been informed that VANS is not the Manufacturer nor the Builder. But I am only guessing here: would not the numbers written in the operating limitations or POH be the guide here? And not what Vans says it may be when completed?
I'm still building my RV8 and have been thinking about limiting the gross weight to get a slower Vs1 in order to qualify for MOSAIC (as the NPRM is currently written). I found the following formula for computing changes in stall speed:
Vsnew = Vsold x √ (new weight /old weight)
When I run this formula using the Vs1 info on Van's website (55.6 KIAS), I come up with a 1700 lb gross weight RV-8 will have a Vs1 of 54 KIAS. Since the airplane isn't certified yet, I will be able to satisfy the continuously met the requirements part of the regulation.
I know giving up 100 lbs payload isn't something to do without serious consideration, which brings up the next question: how hard is it to increase the GW of an airplane after it has an airworthiness certificate?
I'm curious what others think about this kind of approach.
As others have pointed out you need to use Calibrated Airspeed. Both aircraft I have owned appeared to have the IAS lower than the CAS by about 5 to 6 knots. This was based on the very unscientific method of slow flight down the runway on dead calm mornings both directions cross checking the GPS. In addition I think the bigger hurdle will be insuring the aircraft. I doubt the insurance company will buy off on no medical for a RV8.
They will accept what the FAA considers valid. I am just not sure they will buy off on a RV8 meeting the FAA requirements. It’s going to be very close. I suspect the FAA will issue some clarification on how amateur built aircraft will be evaluated.
I don't think the idea is to add more old 50 year old designs to the LSA category. I believe the intent is to be able to let all those innovating LSA manufactures that are limited from building a more robust and efficient airplane due to the current FAA regulations, to be able to do that plus add safety equipment which they can't now because it would put the max weight over FAA max limits.
As I understand, if the aircraft has been previously certified as experimental or otherwise then FAA will not allow an owner to go back and "recert" under sport rules.
As I understand, if the aircraft has been previously certified as experimental or otherwise then FAA will not allow an owner to go back and "recert" under sport rules.
There is no certification "under sport rules". If an airplane meets, and has met continuously since original certification, LSA operating parameters, it may be flown by a sport pilot regardless of aircraft certification.
There is no certification "under sport rules". If an airplane meets, and has met continuously since original certification, LSA operating parameters, it may be flown by a sport pilot regardless of aircraft certification.
The exact wording in the new rules is "[clean stall speed] at the maximum certificated weight and critical CG location."
There is an implicit assumption that the clean stall speed, in CAS is part of the certification of the aircraft. That is not the case for all existing aircraft.
The V speed chart that Van’s put out to show where the airspeed indicator markings would be shows both stall speed with full flaps and flaps up as approximate indicated airspeed. None of the other V speeds say approximate. Makes me wonder.
The V speed chart that Van’s put out to show where the airspeed indicator markings would be shows both stall speed with full flaps and flaps up as approximate indicated airspeed. None of the other V speeds say approximate. Makes me wonder.
Not sure if it helps the conversation any, but here is a comment made by CAFE test.
"Clean 1-G stalls occurred between 56-59 mph with full flaps and 60-63 mph clean, depending upon weight. CAFÉ calibrated stall speeds, which are lower due to installation/position error, can be found in the measured performance section. The slowest 1-G stall we measured, at a flying weight of about 1400 pounds and using the Triaviathon rule of 15” mp/1500 RPM, was 47.5 mph!"
Now .. The Clean Stall for YOUR RV8 A ... Assuming you built it... needs to be determined during Phase 1. You didn't buy an Airplane ( you bought a bunch of aluminum) from Van's so you can't use Van's demo aircraft performance numbers. So .. the builder becomes the aircraft manufacturer, and if you built it with Stall strips, would YOUR (RV8 A) airplane be tested for all performance numbers .. including "Clean Stall Speed" with Stall Strips attached?
