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  #11  
Old 05-06-2020, 12:31 PM
sblack sblack is offline
 
Join Date: Dec 2009
Location: Montreal
Posts: 1,456
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Quote:
Originally Posted by smokyray View Post
Hey GH,
I started experimenting with slower approach speeds which took practice with my Sterba "big bite" wood prop. I found that slowing to 65Knots (70mph) on downwind and trim almost full aft the RV4 would get into a "groove" where you control aimpoint with pitch and sink rate with power. At 60 Knots, power on and a fairly nose high approach the airplane would not float and you literally could fly it right to the ground, flaps fully extended.
The best part was my flaps stayed down and I could now quickly retract them for proper STOL quick stop technique. I also made a few small adjustments to my flap handle to keep it where I put it, mainly filing it with a more pronounced notch.
Email me offline if you have any questions...
V/R
Smokey

smokyray@rocketmail.com
This is a good technique for minimizing landing distance etc. Basically you are flying on the back side of the power curve where more thrust is required rather than less as you slow down. This is how Eric Brown managed to land a mosquito on a carrier even though the normal maximum allowable speed for the arrestor gear was 20mph lower than the power off stall speed of that airplane.

The only downside (no pun intended) is that if the engine quits you are screwed. You have no energy and reduced lift margin to stall. You are in a corner and there is no way out but down. With a power off glide you don?t have that issue, but there are other disadvantages like floating, increased landing distance etc. Nothing is free. Just be aware of the risks. Perhaps try it high up to see how much height you need to get enough energy back to flare. You might be surprised.

Whatever anyone chooses to do, and your risk level is your decision, you should fix the flap handle. An uncommanded change in flap position should not be tolerated.
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Old school simple VFR RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2020
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  #12  
Old 05-06-2020, 07:02 PM
Scott Hersha Scott Hersha is offline
 
Join Date: Jan 2005
Location: Cincinnati, OH
Posts: 1,558
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Any short field landing, where you are slowed to min maneuver under power might result in landing short if your engine fails on final, but it is something that needs to be practiced if you plan to use this technique for real. We should all practice this if we have a destination requiring a very short landing, maybe with obstacles, before we actually need it. This works very well in an RV (especially an RV4). Another thing that we should always practice, and something I see violated too many times, is the plan that I need to keep the airport/runway within gliding distance of my airplane with no power, whenever I commit to land there. If I have traffic in the pattern ahead of me preventing me to do my normal approach, I stay at my initial approach speed, around 100K, until I’m ready to ‘commit’ to a landing, which is the point that I can make the runway if I have a power loss.

When I transitioned from an RV8 with a constant speed prop to an RV4 with a fixed pitched prop, this required a fairly major shift in energy management for me - for the better if you value your time before touchdown (somewhere) in the event of power loss. My RV4 will glide like a sailplane, seemingly, compared with my previous CS RV8, which had a glide range of an airplane with no wings. Sink rate could exceed 1000’ per minute, and I needed some energy to arrest that sink rate in a normal power off landing, without flirting with an accelerated stall. I exaggerate a little here, but the difference is real, mostly because of the FP V.S. CS prop. Crossing the end of the runway in my RV4 at 60 KIAS with full flaps and idle power leaves me plenty of cushion for a comfortable flair to a 3-point, not quite stalled landing. Full stall 3-point usually results in a tailwheel first touch down (and I have the long gear), which I do occasionally, but that’s not what I’m trying for.

OK, I’ve hijacked this thread - flap position integrity in a manual flap RV4 is the OP’s problem. I say, fix those notches. Manual flaps is a big advantage in my opinion, in more ways than one. I’ve had 5 RV’s, 3 of which I’ve built, and this is the first one I’ve had with manual flaps. If I were to build another (never say never), I would build manual flaps. Lighter, simpler, zero maintenance, instant up/down. What’s not to like? Tell your GIB to move his left foot over for a second while you position your flaps. What’s hard/inconvenient about that? For you guys that have never experienced these, you don’t know what you are missing.
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SH
RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015
RV4/bought 2016/sold/2017
RV8/2018 built/Sold(sadly)
RV4/bought 2019 Flying
Cincinnati, OH/KHAO
JAN2020
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  #13  
Old 05-08-2020, 07:13 PM
GHARBEN GHARBEN is offline
 
Join Date: Nov 2019
Location: Gainesville, Georgia
Posts: 21
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I certaintly appreciate everyone's help on this flap issue. It is amazing to recieve this kind of support on RV's. With everyone's thoughts in mind, I have decided to replace the 1/8" thick latches with 1/4" thick matetial.
This should fix the immediate problem. I may look at the electric option later.
Thanks to everyone for your help.
G Harben
RV 4
N12HR
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