Flaps - speeds & strength

[born2fly]

Like lots of folks, I have trouble slowing down my RV6. I have to pull back to 8-10" to get down to flap speeds, and my shock-cool warning goes off regularly. When I can finally get the flaps down (100kts for half), I get some serious drag, and I can feed some throttle back in. The only other choice is starting to slow down 25 miles out - which I do but I don't like it. Thought about speed brakes, but what a chore to install!!!

What I'd LIKE to do is put the flaps out earlier, like maybe at 120kts - but I'm concerned about busting something. Does anybody know:
> What's the weakest part of the flap system?
> What can be done to deploy flaps at higher speeds safely?

Thanks,
G.

[PCHunt]

A couple of flight techniques you might want to try:

After slowing to 130 or 140, pull the nose up and climb (while the power is reduced). After a couple or three hundred feet, you should be slow.

Do a steep turn, say 45 to 60 degrees, and pull some G's, say 1.7 to 2 G's. That will also slow you down.

If you try to slow down in a descent, it will take forever.

[Geico266]

I'm not sure shock cooling would be a factor in the pattern. You are slowing down from cruise anyway, and the throttle should be at a much lower power setting than cruise so you are cooling the engine off to begin with. 100knts for flap speed seems high to me, I thought is was like 80MPH.

What kind of cooling alarm do you have? What are it's parameters and who set them?

[Mel]

PLEASE do not exceed maximum flap speeds recommended by Van. The flaps carry more load than any other control surface. They are the only control surfaces that are pulled into the airstream and stay there.

[L.Adamson]

Originally Posted by Geico266

100knts for flap speed seems high to me, I thought is was like 80MPH.

My Van's RV6 builders manual lists 110 mph for 20 degrees of flap & 100 mph for full 40 degree flaps.

110 mph = 95.59 knots

L.Adamson

[plehrke]

I to have my alarm on my EDM-700 go off in the pattern if not carefull. Typically it will be when I am doing touch and goes as you go from full power take-off/climb and then bring the power back on downwind and I pass the 60 deg/min cooling set in the EDM-700 defaults. I typically do just as PCHunt suggests a steep turn to base to bleed off speed or a short climb on down wind to keep from over cooling the cylinders by bring back too much throttle.

I would also suggest refraining from trying to increase the flap speed. Use pilot technique instead.

[PCHunt]

Actually, when I suggested a steep turn, I would do this before entering the pattern, a few miles from the airport, to dissipate energy.

I do NOT recommend 2-G turns from downwind to base!!!!

[Kahuna]

I did a night formation departure on the wing this year and it was not until my lead was pulling away from me on departure 130kts that I knew something was wrong(remember I have a 6cyl, he was a 4 cyl.). I went to route (took spacing) and immediately, duh, flaps are down. So my full flaps are good to 130kias at least once. I have not repeated it. I also have the hex rod installed.

I typically drop 15 degrees at 130kias to get the drag chute going if I come blasting into the pattern. Works well for me. I try to come in high and fast for safety (ok fun too) where I desire to drop flaps some to get slowed down quicker.

My experience in my plane only.
Shame on me for not checking, shame on him (Speedy) for not catching it on the position and hold.(Part of his job before we launch).
Best,

[Mike_ExpressCT]

Just remember the cardinal rule: You can go down or you can slow down, but you can't do both!

Like many say, it's probably going to be an exercise of just thinking ahead a little more. Don't worry, you'll figure it out, just start to slow down sooner than you think you need to.

[flyeyes]

Originally Posted by Kahuna

I typically drop 15 degrees at 130kias to get the drag chute going if I come blasting into the pattern.

Hi Mike, I don't want to be rude, but you might want to think this one through.

Are the flaps stock on your "Super 8?"I recall that there are some areas of pretty significant beef-up

Someone more knowledgable than me can interject here (cough..Kevin../cough) but it is my understanding that the aerodynamic force on the flaps increases with the third power of speed.

This means that if the flaps are designed for 95 knots at partial extension (per Van) then 130 knots is about a 2.5x overload.

I understand that the limits are probably conservative, and that the (non-hex) flap rod has been shown to be the weak point, at least on -6s, but repetitive loading this high may not be a good thing.