New Aerobatic Bi-Plane also an LSA

Wow this is a neat looking light sport. I want to see what it's specs are with he locoming engine.
:yes:
 
I saw at OSH last year, very slick. I want. Bad.

I was wondering when someone would come out with an LSA biplane. If I was looking for a sport plane, that would be the one. IIRC, with the Rotax it has pretty decent range, as well.
EDIT - 15 gal, so about 3 hrs of fuel. Not too shabby for a sportplane.
 
Last edited:
It flys just as good as it looks. The four near full span flaperons offer a great roll rate. We timed the roll rate from 60 degrees bank to 60 degrees bank at 1.03 seconds. It also has a large rudder and elevators offering great response. The controls are very welll balanced but the aircraft is not twitchy.

The AEIO-233 will increase the empty weight by about 40 pounds compared to the Rotax but it should have about 24 more hp (about 25% more). We're hoping for a gross weight increase also due to addition of mini winglets on the tips. Right now, the only thing limiting the weight is the LSA clean stall speed of 45 KCAS and the designers desire to keep the performance very crisp.

Some cool features are wings that fold to about a 10 foot width in about 7 minutes. There are four different canopy configurations that can be changed in a matter of minutes also. There are even two luggage compartments available incase you want to take a cross country.

I'll have more info available as testing on the AEIO-233 progresses.
 

Attachments

  • DSC02125.JPG
    DSC02125.JPG
    610.4 KB · Views: 81
  • DSC02102 (2).JPG
    DSC02102 (2).JPG
    1.2 MB · Views: 76
Interesting choice to put flaperons on a bipe. Bipes are typically so draggy with the two wings, flying wires, I-struts, slave struts, and cabanes that the idea of flaps seems a little silly. Interesting airplane. The FK website indicates a +14/-7G ultimate load limit...meaning that's when it breaks. That means a +9/-4.6G operational load limit. That's not made clear in the video...not that it matters much. That's still plenty for anybody who will be flying this type of airplane. It's a very light airplane, which helps achieve the high load limits.

The double swept wings should make for a great snap-rolling airplane. I don't understand why they put forth the impression that it cannot do any aerobatics at all with the Rotax engine. The Rotax doesn't have inverted systems, but basic acro can be kept positive G. This airplane wouldn't handle much like a Pitts on the ground with its 40mph stall speed and wide spring gear. Should handle very similar to most other small, light tailwheel LSA's. Being a biplane has nothing to do with ground handling. It just means worse visibility on the ground. Not sure why they were talking about the supposed difficulty with the tailwheel setup. It's steerable, just not castering, which simply means you can't pivot the tail in a tight radius. I had an RV-3 with a steerable, non-castering tailwheel, and it worked just fine. If my circumstances required me to fly without a medical, I'd like to have one of these.
 
Last edited:
Looking forward to hearing the Lycoming performance numbers. I think this airplane can fill a niche that has been vacant for a while.
 
The aircraft was designed to be flown off small grass airfields in Europe. The flaperons are for getting in and out of the short fields. They also help improve approach visibility by providing a more nose down pitch attitude. You can get it slowed to an approach speed of 50 KIAS and touch down around 35-40. It doesn't take much of gust to go from rolling out nicely to flying again so like any other aircraft, you have to fly it all the way to the hangar.

Since it is designed for grass strips and the original model doesn't have differential braking, the tailwheel steering is directly linked to the rudder. No springs or castoring in the system to dampen out inputs. Good on slick grass but it requires a different technique on hard surfaces. I think "Freeze your feet" as the tailwheel touches down and then "Smaaall inputs" for the roll out. Nothing new but it is real easy to over control if you don't pay attention. Differential braking and and a castoring tailwheel options will will give it a more conventional feel.

There is no shortage of videos on the web of Comets doing aerobatics with the Rotax. These guys have either built a kit or just don't care about limitations in the POH. Unfortunately Rotax puts the statement "This engines is not suitable for aerobatics" in all of it's engine manuals. This means that no SLSA manufacturer selling planes in the US is going to allow aerobatics in a ROTAX equipped aircraft. Hence the installation of the Lycoming which has no such prohibitions.

The Comet isn't actually designed specifically as an aerobatic aircraft. It is a Light Sport Aircraft that will be capable of aerobatics once all regulatory hoops are jumped through. Based on it's capabilities so far, it ought to do well in the sportsman categroy.
 
maddog52 said:
The aircraft was designed to be flown off small grass airfields in Europe. The flaperons are for getting in and out of the short fields. They also help improve approach visibility by providing a more nose down pitch attitude. You can get it slowed to an approach speed of 50 KIAS and touch down around 35-40. It doesn't take much of gust to go from rolling out nicely to flying again so like any other aircraft, you have to fly it all the way to the hangar.

Since it is designed for grass strips and the original model doesn't have differential braking, the tailwheel steering is directly linked to the rudder. No springs or castoring in the system to dampen out inputs. Good on slick grass but it requires a different technique on hard surfaces. I think "Freeze your feet" as the tailwheel touches down and then "Smaaall inputs" for the roll out. Nothing new but it is real easy to over control if you don't pay attention. Differential braking and and a castoring tailwheel options will will give it a more conventional feel.

There is no shortage of videos on the web of Comets doing aerobatics with the Rotax. These guys have either built a kit or just don't care about limitations in the POH. Unfortunately Rotax puts the statement "This engines is not suitable for aerobatics" in all of it's engine manuals. This means that no SLSA manufacturer selling planes in the US is going to allow aerobatics in a ROTAX equipped aircraft. Hence the installation of the Lycoming which has no such prohibitions.

The Comet isn't actually designed specifically as an aerobatic aircraft. It is a Light Sport Aircraft that will be capable of aerobatics once all regulatory hoops are jumped through. Based on it's capabilities so far, it ought to do well in the sportsman categroy.
Click to expand...

And if a potential buyer were not interested in aerobatics, could he or she elect the Rotax for the weight savings and whatever fuel savings might be realized?

-Rich
 
RJM62 said:
And if a potential buyer were not interested in aerobatics, could he or she elect the Rotax for the weight savings and whatever fuel savings might be realized?

-Rich
Click to expand...
Definitely!!! There are already more than a hundred flying with the Rotax as it is standard equipment. The aircraft performs very well with the 912 and is alot of fun to fly.
 
I would assume the problem with aerobatics and the Rotax is the gear box but many semi- aerobatic planes do use the Rotax. Murphy makes a little bipe, the Renegade, that is stressed for it and uses the Rotax.

Anyway the plane looks very nice indeed.
 
maddog52 said:
Definitely!!! There are already more than a hundred flying with the Rotax as it is standard equipment. The aircraft performs very well with the 912 and is alot of fun to fly.
Click to expand...

So, y'all giving rides? I'll trade you a ride in the RV-6. ;-)
 
They have been advertising it as fully aerobatic with the Lycoming without a flying example for over 2 years so far........ :dunno:
 
I would love to fly one, what a cool option for an acro LSA. I would like to see how it would compare to an Eagle or Pitts. The flaperons would be useless to me though I feel like. I have never needed more of a nose down pitch attitude in the Pitts.
 
Inverted said:
The flaperons would be useless to me though I feel like. I have never needed more of a nose down pitch attitude in the Pitts.
Click to expand...

Yep, flaps on a bipe are pretty silly. But I'll bet the flaperons are there to accomplish the "clean" 45KT LSA limit on stall speed. Since the flaperons are also the ailerons, I'll bet there's a technicality that allows this airplane to have only one landing/stall speed configuration, not two...as a plane with dedicated flaps would have. Otherwise, I can't figure why you'd bother with them on a plane like this...unless you're trying give them flaperon effect like the Ultimate Bipe had for high AoA stuff. :) But I'd bet against that.
 
whifferdill said:
.... But I'll bet the flaperons are there to accomplish the "clean" 45KT LSA limit on stall speed. Since the flaperons are also the ailerons, I'll bet there's a technicality that allows this airplane to have only one landing/stall speed configuration, not two...as a plane with dedicated flaps would have. Otherwise, I can't figure why you'd bother with them on a plane like this...unless you're trying give them flaperon effect like the Ultimate Bipe had for high AoA stuff. :) But I'd bet against that.
Click to expand...

Incorrect. No waiver possible for the LSA clean stall speed. Clean stall for the FK 12 is around 44 kcas. No other configuration/stall speed is required for LSA. As stated earlier, the flaperons are for short field operations and do make a differnece in speeds and distances. It also makes a big difference in approach attitude and visibility.

The FAA implemented new rules last July on new LSA certification and they decided this is a new aircraft even though it had already flown with an AWC. Unfortunately the new rules can be confusing and even the FAA is inconsistent in their interpretation. It's been a long and frustrating processes but there is light at the end of the tunnel.

Any SLSA equipped with a Rotax 912 won't be allowed aerobatics because Rotax disallows it. "This Engine not Suitable for Aerobatics" is in all the installation manuals for the 912 series. EXAB aircraft don't have to worry about the restriction.

The biggest problem with the gearbox for aerobatics would be that about a quart of oil (about 1/3 of total) would settle in it during sustained inverted flight. Of course the floats in the carbs would also make sustained or even momentary 0 or negative G flight impossible. Positive G aerobatics wouldn't be a problem except for the manufacturer's prohibition.
 
maddog52 said:
Any SLSA equipped with a Rotax 912 won't be allowed aerobatics because Rotax disallows it. "This Engine not Suitable for Aerobatics" is in all the installation manuals for the 912 series. EXAB aircraft don't have to worry about the restriction.
Click to expand...

Correct. They just have to worry about the oil system not working while inverted (or very far off ball in the center coordinated). The 912 doesn't like air in the lifters - just look at the procedure for bleeding the lifters if you disconnect the oil intake line that was implemented after engines were damaged.

Also, there is the issue that there is no way to get oil to return to the tank when inverted. You can't apply the typical inverted oil system because the crankcase does not have a breather. And, you can't add a breather because the oil system relies on pressure from blowby to return the oil to the tank. And since the tank only holds a couple quarts, it doesn't take long to run the oil system dry if you are still pumping oil.

"Traditional" aircraft engines (without inverted systems) have been used for aerobatics under the assumption that a few seconds without oil pressure is not going to cause significant damage. I wouldn't count on that with the Rotax 912 and the lifter issues.
 
Actually, FK decided to terminate the relationship with Renegade. The excessive delays with the development and Renegades plan to try to build a direct competitor for the Comet forced the call. The FK factory will produce it's own installation with the AEIO 233 and another aerobatic capable engine.
 
maddog52 said:
The FK factory will produce it's own installation with the AEIO 233 and another aerobatic capable engine.
Click to expand...

Any idea on the timeline? Are they starting from scratch or picking up where Renegade left off?
 
Smutny said:
Any idea on the timeline? Are they starting from scratch or picking up where Renegade left off?
Click to expand...


The FK factory will be starting from scratch but considering they have the expertise to actually design and build aircraft, they estimate early summer.

My dad talked to Steve Wolf yesterday. He confirmed that he would indeed offer aerobatic training to anybody willing to enroll in his school. He also said that he has no deal or affiliation with Renegade and is not happy about them saying he does.

It will be interesting to see how they solve the 45 kcas clean stall speed required for LSA.
 
You must log in or register to reply here.
Back
Top