Don't use a 5 amp fuse on your electric flaps!!!

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Brantel
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Don't use a 5 amp fuse on your electric flaps!!!

Post by Brantel »

Not sure how I missed all the post about not using a 5 amp fuse on your electric flaps but I did and my fuse blew at the worst moment it could have.

Since I am but a pup on this whole taildragger experience, I sometimes need to "go around". It is not cool when your realize too late that your electric flaps are not retracting and you must manage power, altitute and speed to get turned around and back on the ground! Expecially when you are only 5 hours into Phase I on a brand new airplane.

Apparently my fuse blew either when extending the flaps for the landing or when I tried to raise them for the go around.

All went OK but the pilot needed a break after that ordeal. I put in a 7.5 amp and flew later in the evening and all was well.

Anyway, it is nice to know that an RV7 with a O-360/FP with a DA of around 3000ft does have enough performance to climb to safe turn around altitude even with full flaps. Matter of fact you must be carefull not to exceed flap speed.
Brantel (Brian Chesteen),
RV12-IS, #121606, N912BC - Building Now!
RV10, #41942, N????? - Project Sold
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smithhb
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Post by smithhb »

Yup. Fortunately, I found out the first time I had blown the fuse when I was taxiing out for TO from a fly-in breakfast. Fortunately, I had a spare fuse.

I have determined that if I try and lower my flaps above 80 kts the fuse will blow.

I still run a 5A fuse because just increasing the amperage of the fuse does not mitigate the draw on the flap motor.
Bret Smith
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Blue Ridge, GA
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TomC
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Post by TomC »

Apparently my fuse blew either when extending the flaps for the landing or when I tried to raise them for the go around.
Been there, done that! My solution is the same as yours. After 5+ years, the 7.5 has not failed (peck on wood). In my opinion, as long as you don't repeatedly exercise the flap motor in a high load condition, it should not hurt the motor. Watch your flap extend speed and flap operation in high power situations. Everyone knows about the flap extend speed but realize that the prop wash at high power settings applies alot of force to the flaps as well no matter your airspeed.
Anyway, it is nice to know that an RV7 with a O-360/FP with a DA of around 3000ft does have enough performance to climb to safe turn around altitude even with full flaps. Matter of fact you must be carefull not to exceed flap speed.
Sometime during your phase 1, try a reduced power take off. Its amazing how little power is required to takeoff and climb in an RV.

Good Luck!

Spike
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Post by Spike »

I believe this is probably the basis for the flap / climb requirements in certified aircraft. There are specific climb requirements with flaps down.

Spike
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cjensen
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Post by cjensen »

smithhb wrote:I have determined that if I try and lower my flaps above 80 kts the fuse will blow.
:wink:
I hope my arm doesn't blow out on me when lowering my flaps at 80kts! :lol:
Chad Jensen
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Brantel
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Post by Brantel »

Chad,

Your gonna love your manual flaps.

I have never heard someone that had manual flaps say that they wished they had electric ones.

Makes you wonder why they ever invented electric flaps for small planes.

The electrics work but they have more failure modes and you have no feedback.

The only problem I could see with manual is that you could dump them too fast. Not gonna happen with the electric ones...
Brantel (Brian Chesteen),
RV12-IS, #121606, N912BC - Building Now!
RV10, #41942, N????? - Project Sold
RV-7/TU, #72823, N159SB - SOLD

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smittysrv
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Post by smittysrv »

I hope the delrin grip on the flap rod loosens up over time. It's pretty darn tight. Drop of oil maybe? I can see where that motor is going to be straining trying to move that puppy.

1:1_Scale
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Post by 1:1_Scale »

cjensen wrote:
smithhb wrote:I have determined that if I try and lower my flaps above 80 kts the fuse will blow.
:wink:
I hope my arm doesn't blow out on me when lowering my flaps at 80kts! :lol:
Carpal tunnel? :P
Kelly
RV-7 Empennage done, wings done, fuselage to QB stage
1947 Stinson108-1 flying

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