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flap handle...

777Dave

Well Known Member
Have been considering electric flap conversion for a while but really don't mind the manual flaps except that I have discovered that sometimes when I take full flap, even below 80 mph, the handle doesn't fully engage into the notch on the side of the seat. After playing with it on the ground for a bit, I can see that when there is an air load on the flap, you have to pull fairly hard to extend them and in doing so the handle tends to twist enough that the bottom edge doesn't enter the slot...somewhat uncomfortable feeling.

Has anyone reinforced their handle to keep it from twisting? Seems like I may try that starting right at the base of the handle itself. Comments?
Thanks
 
The notch..

I haven't had any issue with full flaps. But my first notch position is not as positive as full. You might want to take a look at the notch itself.

I've never noticed the handle twist. But I've never looked for it either. It's going to rain here for 4 days. So, I doubt i'll be looking at it soon :-(

John
 
flaps and arms...

Thanks John... The detents on my a/c are very positive and secure when there is no load on the flaps and in the air, the first notch is fine also but the second is hit and miss and I think the "twist" when I pull hard is the reason.
Because of the lack of elbow room, when I pull up, my wrist tends to rotate counterclockwise and twist the handle in the same direction... goimg to have to play with it on the ground with someone holding the flaps up and me sitting in the seat to see if I can adjust the way I hold my arm and pull.
As I mentioned ,I really would rather stick with the manual flaps I think.

Cheers
 
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like many things.....

I thought I would also immediately install the electric flaps. After living with the manual flaps, I see no reason to change them. I think your idea of practicing is a good one.

I also had an issue when I first bought the plane. After applying full flaps, I couldn't retract them. One day I had to do a go around (due to wind sheer that's my story and I'm sticking to it!!). I was 200 miles from home with full flaps and **** near pulled the handle out trying to retract them. I finally relaxed for a minute and carefully watched the handle noticing that it was necessary to pull the handle in (toward the centerline of the plane) slightly before pulling up and out of the notch. Never had a problem since, but would have been much easier to figure out on the ground....

Later

John
 
Can't remember were this data came from but....

It said to twist the handle in the opposite direction in order to mitigate the problem while using the flaps. It also said that if the handle is twisting, a high load is on the flaps and that airspeed should be decreased prior to lowering to the next step.

I am not flying yet but plan on doing it. The information came from the RVator or my plans.
 
Reinforced my flap handle

This is a common Art Chard mod. He builds RV's on contract and was a long time employee and prototype builder at Vans. It seems to work fine in the shop. My airplane isn?t flying yet. The reinforcement was simple to accomplish as you can see by the photo.

 
!

YES Brian, that's exactly what I was thinking!!!!!!!!!!!! Should solve the problem nicely. Thanks for the pic.
For me, this is a safety issue... don't want flap to retract at the "wrong" time. I will do this mod ASAP.

Cheers
 
Notch Problem

Dave,

I'm thinking you have a notch problem. What you describe is very common in RV-4s. I'm flying my second -4. Put 1,440 hrs on the first one without ever having the "flap slip" problem.

I couldn't get the handle to stick in the second notch on my present -4. Would use only the first flap for landing. Thought the problem was my expanding BUTT due to beer and BarBQ.:eek:

One day, some time past, I clicked on SafeAir1's site and looked at their link to Darrell Morgan's Firebird Aviation. He has a 1.85MG download of his rebuild of a RV-4. On page 13 of 15, he has excellent photos of his solution to the notch problem. It is a laminated build with deep detents. I copied it and do not suffer the slip problem any more. (Thanks mucho Darrell!!)

Try this link: http://www.firebirdaviation.com/FA1_content/Rbrth Full_e.pdf

If that doesn't work for you, go to www.SafeAir1.com and click on Firebird Aviation. It is really a good fix. I personally don't think the flexing handle is your real problem. Just get a good detent that will hold the handle.

Best of luck,

Deal Fair

RV-4 Flying (when I get my P-Mags back)
George West, TX (8T6)
 
Thanks for your reply and link Deal. I will have a very close look at my notches too. I have never had the flap handle actually slip out of the notch but I have had it fail to fully engage so it may need reworking or replacing. In my case, the handle partially catches the notch sometimes and seems to stay there but is obviously not right. I think the twisted handle is the key but will play with it some more to be sure. Won't get a chance to do any work for a couple of weeks. (work):rolleyes:

Thanks again.
 
I like the reinfored handle idea also. It appears too easy of a fix not to do. I'm going to add that too. Good photo Brian.

Thanks all,

_______________________
Deal Fair
RV-4 (N34CB)
George West, TX (8T6)
 
I had this same problem on the -4 we bought. I used the existing bracket mounted on the seatback as a template and made a new one with deeper detents.
On a flying -4, the bracket fix might be easier than reinforcing the flap handle.
 
I hate to bring this one back from the dead--but I'm having the exact same issue on my -4 and all the pictures/links are non longer valid so I was hoping to see if anyone had another source they could share versus re-inventing the wheel; the whole "picture is worth a thousand words" theory. I found Arts email in another (circa 2008) forum post but that email address is no longer valid either.

I keep it under 100mph before I even touch the handle so at this point, I think being a 34 year old RV--the handle and/or detents (which are slightly rounded) need a little work to get back in spec. My original idea was to simply build up the detents so the slot is effectively 'deeper' to prevent the flaps (specifically the second notch) from slipping out of position--but if there is a more effective/easier way to correct this, I'm all ears!
 
Flap Handle

My 4 is "only" 29 Yrs Old, but I have found that it requires much less force to get the second notch of flaps on if I get the IAS down below 80 Kts first. In fact if I try to deploy the 2nd notch of flaps and feel a high resistance to moving the handle, I check the AS and lift the nose a little to get it there.

Having said that, I did add a .060" thick plate to the outside of the 2nd notch block on the side of the seat a few years ago. It creates a ledge for the flap handle knife edge to bear against when the flaps are deployed. I did that mod after the flap handle slipped out of the notch on a landing. Landing came out ok, but surprised the heck out of me when it happened.

Mel B.
 
Had a similar issue getting the handle to the full flap notch, the gear handle finally BROKE where it attaches to the round stock.
We repaired the handle with a weld, and lowered the full flap notch a bit on the side of the seat.
Also, I made sure that the angle on the bottom of the gear handle matched the angle of the notch on the seat.
Everything works now, although it can be finicky. I will definitely look into the mods posted here.

Thanks!
 
For what it's worth, it has been corrected for now. After doing some slow-flight and looking closer on the ground, I removed the flap handle and placed it in my vice; took some channel locks and tweaked the section that catches the notches--inboard towards the seat. Now it engages positively. I now just leave the flaps down when hangared as it relieves all pressure off the bar and I'd presume will increase time between the next adjustment.

Sometimes it's easy to overthink things.
 
Mod

Funny to see this thread reappear😉
In the end I went electric and don't regret it at all. Pretty easy mod and of course, eliminates the handle.
 
Nothing new under the sun...

Funny to see this thread reappear😉
In the end I went electric and don't regret it at all. Pretty easy mod and of course, eliminates the handle.

Yes it seems there are no new questions or answers. just new people asking them. :)
I built my RV4 per the plans in the last century before internet chat groups. The builders group posted a article on the now defunct "RV8R" newsletter for a flap handle "stair step" mod. I installed it on mine which makes it impossible to pop out of the detent without pulling slightly up first. I also "reflexed" my flaps in the bottom notch per the Maule Flap arrangement with a 2 degree up flap past neutral. This added a knot or two in cruise, just as it does on the Maule.
I like manual flaps for STOL takeoffs from soft turf, STOL landings to raise immediately upon touchdown and of course the perfunctory 1V1 dogfight...:)
V/R
Smokey
 
Found that slowing down my friend?s -4 to 70kts helps in precisely positioning the handle with almost no twist...
Slightly better and more complicated design on the -6, positive locking with the release of the push-knob... also using 70kts here and therefore usually selecting full flaps on finals...
 
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