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Savannah - manual vs electric flaps


petercoota

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I'm trying to make the choice between manual & electric flaps. I've done about 12 hours in a Sav with manual flaps & still found the control awkward, even after that experience. Peter Gillespie gave me a further demo at AUSFLY recently, I'm still hesitant. 

 

I understand the desirability of instant flaps at low levels, as available with manual operation. 

 

My question is to those who have electric flaps - just how quick, or slow, are they to respond?

 

All comments, from manual or electric owners welcome!

 

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Stick with Manual. If you ever have a flap asymmetry, you'll be in a better position to handle it. Flap asymmetry is NEVER really mentioned in  discussion on U/L's and it's a failure mode of some jeopardy.  Nev

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No experience with Savannah systems .

 

C172 Electric Flaps - slow as - always had to glance back to check position (could be because I didn't trust the staged flap positions). Otherwise worked well.

 

ATEC Zephyr manual flaps - great! The low wing tends to fly on in ground effect but you can dump/lift flap when mains a foot or so off ground & wing stops flying - very handy when conducting short field opps. 

 

I don't thing electric flaps would be fast enough to do the above.

 

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You also get a feel of the air load/speed with manual flaps if you are the sort of person who tends to exceed Vfe and you can feel what position the flaps are at,  Bigger aircraft need some extra power as the loads can be very high and they all have flap asymmetry  protection./checks. Nev

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Did my training in a Jab with Electric flaps. The Sportstar has manual flaps.

IMHO, the manual flaps are much better for the reasons above.

 

25 minutes ago, skippydiesel said:

The low wing tends to fly on in ground effect but you can dump/lift flap when mains a foot or so off ground & wing stops flying - very handy when conducting short field opps. 

I did this the other day with a significant crosswind at Tyabb. Raised flaps as soon as the mains touched, keeps you planted on the ground and stops you being blown around by the crosswind.

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Hi Peter,

 

I just PMed you a response as your original post was throwing some strange error here. But it looks to be okay now.
Here is what I sent:
 

I am 5'8" and fly my Sav S with the adjustable seat one notch back from fully forward.
I found the standard flap handle very awkward, to get full flaps I was not pulling it up, I was pressing towards my stomach, which is not a strong physical action. So I found it clumsy both putting flaps on, and taking them off when doing circuits. Add to this that improperly latched flaps have been known to drop out suddenly, causing considerable aircraft damage in one case that I know of.

So I fabricated a new handle with a 12deg bend in it. It works exactly the same as the standard one and addresses all the above problems, I am very pleased with it. However, I was fortunate to have an engineering buddy do the necessary SS cutting and welding for me, it needs to be made precisely and it is not something I could have made on my own. I have provided sketches to other builders,  but to my knowledge nobody else has done this.

What they are doing here is ditching the ICP handle system entirely, and fitting a slightly modified car handbrake: I believe it is the Suzuki Swift, but I would need to check that. They then grind teeth off the handbrake ratchet, leaving themselves with 3 flap positions (I have the Mark Kyle flap handle mount that gives 3 positions, which I think is a worthwhile change). Since a handbrake only locks in one direction, they then add a spring or bungy so that the flaps do not fall under their own weight while taxiing or parked.

I'm in the N Island in NZ, most of the builders in the S Island seem to be going the handbrake way. If you are interested in pursuing this, I could put you in touch with one of them.

Edited by IBob
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I have electric flaps & it takes about 10 seconds to fully deploy to 30 degrees which is the maximum & a similar time to retract. In a low wing it is easy to see if they are deployed & to what degree as you just glance out the window. I don't have any settings marked so just guess where 10 & 20 deg angles are. I usually flick the switch up at touchdown.

 

I had a Cherokee Archer 2 umpteen years ago & the handbrake style manual flap handle between the seats with the 3 notches of 10, 20 & 30 degrees was the best I have used. Easy and instant to set any position and I could pull the lot on or dump the lot instantly.

 

I have only flown one high wing with manual flaps & that was a Foxbat. I found the location of the lever to the side behind my head pretty awkward & didn't like it at all. I guess if I owned one I'd get used to it. I also didn't like the location of the throttle in that aircraft either.

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Thanks for all the responses. I should have made my original post clearer.

 

I'm considering buying Savannah. If I buy a new factory built model, then I have a choice of manual or electric flaps.

 

My question relates to just how quick, or slow, Sav electric flaps are to operate.

 

There are many good points raised in the responses so far, including asymmetric failure, low ing ground effect etc, my immediate concern is the speed of response of electric flaps on a Sav S.

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I dont mind either electric or manual and I have flown a mix of both.

 

When executing the downwind to base turn, I extend flaps either before OR after the turn, as not to provoke something nasty if the flap went out assymetrically. (suggestion by instructor) 

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Where there's a choice, simplicity is best and why depend on an electric motor and little cogs when you can easily power if by direct hand force and "feel" the mechanism and have near instant response?.  Even the awkward Auster set up is ok when/if you get used to it.. (One of the worst). This is a "no brainer" for me. Nev

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Manual over electric any day...I hated electric flaps on the GA aircraft I flew...I have done a lot of glider flying and they are manual flaps and airbrakes and all the ultralights I have flown are manual flaps...manual is far better than electric any day

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32 minutes ago, Kyle Communications said:

Manual over electric any day...I hated electric flaps on the GA aircraft I flew...I have done a lot of glider flying and they are manual flaps and airbrakes and all the ultralights I have flown are manual flaps...manual is far better than electric any day

Agree Mark; also on final and late final in turbulance you can miss operating the switch.  Whereas you grab the manual flap handle and adjust to what you need.

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  • 2 weeks later...

I count 1000, 2000 and have half flap so that makes full flap about 4 seconds.  I have never measured it but will  next flight.

 

I went for electric flaps when I built - I was originally going to have twin sticks. Then I decided against those but thought I would stick with the electric flaps as it removed the lever between the legs.

 

My flap switch is immediately above the left hand throttle.  I can activate without actually taking my hand off the throttle. 

 

People said stay with manual so you can dump the flaps immediately you land. I'm not into that extreme flying as the landing distance is very short without letting go of the throttle, reaching between my legs and dumping the flap.  If I was going to do anything to shorten the distance I would replace the wheels/brakes with something better.

 

Flap motor failure could occur but a flap-less landing is a non event. Unless you operate in the extreme all the time. 

 

On the plus side you can select any flap setting you want.

 

Asymmetric flap operation. - No difference to chance with electric or manual. They both use the same mechanism. 

 

The ICP electric flap kit is expensive. It is very basic and you could build your own for a fraction of the price.

 

There are documented cases of uncommanded manual flap operation. 

 

Still happy with my choice after 800 hours 🙂

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I trained on aircraft with electric flaps, but my plane has manual flaps and they are very quick and positive to deploy.

Interestingly, the current RV-12 kits have changed to quick-acting electric flaps, but I prefer the manual version. 

Simple, quick and reliable. 

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I have electric elevator trim on the Tecnam and got caught off guard at about 6500ft near Dalby when the trim went full nose down, not nice with a full flying tail plane. Momentarily took me back to aeros in the Bulldog. Recovered safely in under 1500. So naturally I now hate elec control of any flying surface. The sad thing is I am still building a Bushbaby Explorer and already have fitted the Ray Allen trim motor in the elevator, I am now going to de cover the elevator and convert the trim to manual. 
 

The fault with the Tecnam was chaffed cables in the tunnel between the seats, it shorted and popped the circuit breaker once the trim motor run to the end. Another problem which could affect many Tecnams is the throttle mechanism behind the panel, my god who the hell designed that. 
 

steve 

Edited by Steve L
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  • 6 months later...

Having flown the Piper for a bit now, with that huge well located flap lever , I  am a convert on manually operated flaps. The force feedback tells you plenty. At least on that big plane. DIdnt feel much force feedback on the Vixxen. 

I'm inclined to provide some sort of load indicator etc for my Jabiru electric flaps (motor current) . More likely to pick up some issue with flap deployment that way or provide some advanced warning of something amiss/ non square. (or an additional distraction right when you dont need one) 

 

Edited by RFguy
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