Do you guys think this type of aileron would work on RVs?

[AX-O]

I was doing some research and found this web site http://lamaviation.com/advanced-aileron/. I have been trying to figure out how to do this for a long time without making it too complicated (college project). Would be cool to see it on an RV.

[Ron Lee]

I was hoping for something that would increase cruise speed by 5-10 knots. Seems it is geared towards improving roll rate and landing ops (flaps). Since neither of these seem to be a problem in the RV, I doubt that it has any substantive value for my aircraft.

[David Shelton]

To get full advantage from a LAM aileron, it would be necessary to design an entirely new wing that is optimized for those ailerons. Because of the full-span flap feature, the designer would likely choose to reduce the wing area and increase the aspect ratio, resulting in some performance gain. However, it is unlikely that much benefit would be realized by installing them on an existing wing.

[Andy Hill]

From a quick glance at the link, one of the "benefits" of this is to get Flap Type lift from the OB panels ('Ailerons'!). Similar in concept to "droop" ailerons as fitted to various types.

There was a recent post on here stating that Van (?) might have fitted such a system to his early RV-3 (?) - it involved a selector on the stick base that effectively shortened / pulled both Aileron pushrods / reduced the inboard distance between the aileron push rod ends. Immediate thoughts about such a system:

1. For a given speed, you will increase overall lift, and hence fly heavier or with a lower pitch attitude
2. For a given pitch attitude / weight, you can fly slower

which all sounds great - effectively can fly slower on approach / takeoff. Downsides:

1. Reduced roll control / aileron range - not a real problem in an RV, but combined with a lower approach speed, could become an issue in turbulence
2. Increasing the effective angle of incidence of the outer wing, in turn meaning if you do stall, there is an increased likliehood of the outer wings stalling prior the inner - not what you want on approach
3. You are moving the centre of lift of the wing outboard, thus compromising the overall design v max loading. It would therefore need significant limitaitons in use (e.g. 'g'), and safety interlocks to prevent inadvertant deployment [think - you are pulling 5g in a 6g aircraft, the ailerons now droop - lift increases to 7g and that 7g CofL is outboard of design = effectivly 9+g on wing bending

An interesting question, but seems to me it is adding lots of downsides for little benefit in an aircraft that does not need the benefits anyway

Andy

[Andy Hill]

Re Droop Ailerons, found the link: Link to RV-3 prototype article which includes a (poor) picture of the mechanism.

Andy
RV-8 G-HILZ
RV-8tors

[TSwezey]

Originally Posted by Ron Lee

I was hoping for something that would increase cruise speed by 5-10 knots. Seems it is geared towards improving roll rate and landing ops (flaps). Since neither of these seem to be a problem in the RV, I doubt that it has any substantive value for my aircraft.

+1 Just don't see the use in an RV.

[Andy_RR]

How would this improve on the full-span flaperons of the RV-12? I'm not sure quite how this reduces adverse yaw either.

Any clues?

[Kevin Horton]

This seems like a very complicated and heavy "solution".

It reminds me a bit of another very complicated solution I saw many years ago during my first visit to Brazil. One of Embraer's flight test engineers took me out to see his One Design project, and in the same hangar he showed me the K-51. The K-51 was a one-off wooden aerobatic aircraft designed by Joseph Kovacs (standing beside me in the picture), who was Embraer's chief designer for many years. It had the most complicated flap and aileron system I have ever seen. The ailerons drooped when the flaps were deployed, with the amount of aileron droop being about 50% of the flap travel. And, the flaps deflected up or down when you moved the control stick laterally, with the amount of flap movement being about 50% of the aileron movement. I would have loved to see the mechanism that made all this work.



YouTube has a video of an aerobatic routine of this beautiful aircraft, flown by one of Joseph Kovacs' sons. More shots in this television story (all in Portuguese, unfortunately).

[rzbill]

I agree with the above posts that the LAM system is not needed on RV's.

I would also agree with the previous post comparing LAM to droop ailerons. In fact, before jumping on the LAM bandwagon for a aircraft that needed low speed lift augmentation, I would need to see test data that showed the LAM system was better than droop ailerons in all regimes. I am not sure that is the case. When turning left with the LAM for instance, the left wing will have a huge drag producing void between the drooped aileron and the upper split aileron. In a simple drooped aileron system, the left aileron is raised slightly to reduce left wing lift. No big drag change.

BTW. Thanks for the SA article. I still have that issue. Early in my construction I had fleeting thoughts about drooped flaps and remembered that image mentally but sure didn't remember it was Dick that did it on his RV-3 . Not doing droops. Too tough to execute on a side by side.

[Andy Hill]

Not doing droops. Too tough to execute on a side by side.

Not really, if you could accept the neutral point with the stick(s) not vertical... you just put the adjuster on one or other stick

Andy