Flap deployment muscle
Posted: Tue May 14, 2019 5:31 pm
by scotttro
I’m coming up on starting the forward fuselage, and I’ve been thinking about the flap handle. For folks that have some time in the type, how much muscle does it take to deploy the flaps? I’m thinking of shortening the handle a bit, or repositioning it in such a way as I’d lose some mechanical advantage.
Thanks,
Scott
Re: Flap deployment muscle
Posted: Tue May 14, 2019 5:46 pm
by WaiexN143NM
Hi all,
first notch ok, second wow better have eat your wheeties in the am. 3 rd notch better install electric flaps. Just sayin! Flying since 2013.
WaiexN143NM
Michael
Re: Flap deployment muscle
Posted: Wed May 15, 2019 8:39 am
by DCASonex
I concur with Michael’s comment on this. Converted mine to electric flaps after first couple of flights. Each time reached for flap lever, looked like i must have been playing with a yo-yo in the pattern. Can add flaps at any point in landing without getting out of shape. Several accidents in Sonex that looked survivable, but pilot had head injuries. With electric flaps, (and toe brakes) can keep those shoulder belts tight. With flap switch next to throttle, can keep one hand on throttle and one on stick through entire landing. And with throttle (dual in mine) in lower corner(s) of panel, the trim lever can be tweaked without removing hand from throttle.
David A.
Re: Flap deployment muscle
Posted: Wed May 15, 2019 11:10 am
by Jlogan1
im doing my phase one now 9.8 on the hobbs and havent been able to pull full flaps yet. first notch isnt bad. The only time i tried to pull full flaps on landing was a complete failure either i was to fast or i need to hit the gym. im sure it looked ridiculous from the ground.
Re: Flap deployment muscle
Posted: Wed May 15, 2019 2:14 pm
by sonex1374
Full flaps can be really hard to pull at speeds above 80 mph. If you slow up before pulling the full flaps it will be significantly easier. Alternatively, the small flaps that come from the acro ailerons take less force to deploy. This makes it easy to add full flaps even at hi speeds (90+mph). Could be an attractive reason to go that route for those still considering which ailerons to build.
Jeff
Re: Flap deployment muscle
Posted: Wed May 15, 2019 3:14 pm
by andrewp
Hmmm … it is true that there is more force on it and yes it is a lot easier if you slow down but I would have to say it has honestly never really bugged me. I have the physical form factor of young Bill Gates so I guess it should. It is amazing that I can get the canopy open. Anyway, you can feel the airload on it and I sort of like it. Electric in the 182 and I always have to look where the stupid thing to confirm its position (not comparable, but I kind of like the Sonex simplicity here). I don’t have to have my belts loose to reach it, but it might be a shape and size of person thing.
Having said that, electric flaps are cool. I can respect both country and western.
Re: Flap deployment muscle
Posted: Wed May 15, 2019 8:24 pm
by sonex892.
I have standard flaps with three positions and have never had a problem operating the flap lever. The force required, does increase substantially with speed, which is like a built in safeguard against exceeding a reasonable flaps down speed. Also cant beat the simplicity of the standard arrangement.
I don’t think I would consider shortening the handle. I wouldn’t want any less leverage.
Re: Flap deployment muscle
Posted: Thu May 16, 2019 12:04 am
by mike.smith
sonex892. wrote:I have standard flaps with three positions and have never had a problem operating the flap lever. The force required, does increase substantially with speed, which is like a built in safeguard against exceeding a reasonable flaps down speed. Also cant beat the simplicity of the standard arrangement.
I don’t think I would consider shortening the handle. I wouldn’t want any less leverage.
I agree on all points!
Re: Flap deployment muscle
Posted: Thu May 16, 2019 6:56 am
by lpaaruule
I have the acro flaps, so it really hasn’t been an issue for me. I too agree that the force required to pull the flap handle is a nice reminder if you’re a little faster than you should be. Also, having manual flaps allowed me to win a spot landing contest. As soon as I was over the spot, I took out the flaps.
I wouldn’t want the handle and shorter than it is though. If you have to go-around, you’ll want to be able to slowly retract the flaps. At that point, you’ll be happy you have the longer handle.
Re: Flap deployment muscle
Posted: Thu May 16, 2019 1:32 pm
by achesos
I’m jumping to the conclusion that I read between the lines here - you may or may not agree with the following:
- Apparently Sonex designed the flap handle ‘correctly’ so as to remind us that we might be too fast for full flap deployment… probably should not adjust the flap handle length.
- This warning can be easily ignored via the use of electric actuators…
- The resulting forces at the mounting points of these custom actuators were not calculated or engineered by Sonex, and therefore the complete responsibility of the builder implementing this alternate system. What I mean is, you could purchase and install an electric actuator that might have the capacity to deploy the flaps at Vne, but you might only be able to do it once?
My summary assessment then is that electric actuators are way-cool, envied by the manual lever guys (myself included) and easy to use, but should be implemented / used with some caution. Use your checklist. Fly safely. Go home to the one(s) you love.
Re: Flap deployment muscle
Posted: Thu May 16, 2019 2:11 pm
by WaiexN143NM
Hi achesoe, all,
Yes good post , my airspeed indicator is marked for max airspeed flap operating range. I have an arthritic left shoulder and hand. For my situation i love the electric flaps. the bottom attach point is near the forward lower longeron/ firewall corner with an additional angle bracket riveted in. Respect is used with the electric flaps vs. airspeed. A good reminder for the ‘B’ model people with standard electric flap design. Thanks for the reminder to all.
WaiexN143NM
Michael
Re: Flap deployment muscle
Posted: Thu May 16, 2019 3:42 pm
by Bryan Cotton
envied by the manual lever guys
Not me. I like simple, and prefer crank car windows too. I have flown many aircraft with mechanical flaps - Super Cub, Pawnee, Arrow, SGS 1-35, C140, and probably a few others I’ve forgotten.
Re: Flap deployment muscle
Posted: Thu May 16, 2019 4:45 pm
by Friesen5
I agree with the posts that the strength of the pull is dependant on speed. If you’re having problems, I suggest that you check the fit of the slots that the handle fits into. I had to file mine a bit for a looser fit. The air loads can jam the handle in the slots if they are tight.
Mervin Friesen
C-FMNX
Sonex 122
370 hours
Jab 2200
Re: Flap deployment muscle
Posted: Fri May 17, 2019 9:59 am
by builderflyer
No envy of electric flaps for me either. First, if one has difficulty in deploying the manual flaps (at least partially) at speeds under 100 mph, it is time to calibrate the airspeed indicator (if you haven’t already done this). You may actually be going considerably faster than 100 mph. Second, if there is difficulty in retracting the flaps on a go-around, the solution is to widen the lever slot at the back towards the outside of the aircraft so that there is room for the flap lever to twist a bit as it will do under higher loads. Without this widening, my flaps would be impossible to raise from the full down position on a go-around, not exactly a safe situation.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: Flap deployment muscle
Posted: Fri May 17, 2019 8:42 pm
by peter anson
I rarely/never use full flap so find the manual flap lever OK. Don’t know if the Sonex plans have changed but you should definitely add an intermediate stage, which is what I use normally for landing and you should definitely not make the full flap notch with that hook arrangement. The hook caused me a great deal of grief on a couple of occasions before I got rid of it.
Peter
Re: Flap deployment muscle
Posted: Sat May 18, 2019 7:12 pm
by dtwolcott
I agree with Peter. I used full flaps on a landing and needed to do a go around after being very close to landing. I tried to raise the flaps and the handle did not want to come out of the slot. I did learn that the aero vee did have enough power to climb out to pattern altitude with full flaps deployed. I sure don’t want to do that again. I also have cut an additional slot for intermediate flaps and that is all that is needed.