Extending flaps while banked (pattern altitude)

[Tom BravoMike]

I have just read this article:

https://pilotworkshop.com/tips/extending-flaps-while-banked/

I know it's about power airplanes, but I keep in mind an accident a
friend of mine had in an ASW20, stalling and spinning (survived with
serious injury) when extending the flaps in base to final turn. Ever
since I basically move the flaps to positive (Ventus B) only when I'm
already on the final .

What is your experience/opinion?

Tom BravoMike

[Eric Bick (DY)]

On Wednesday, June 14, 2023 at 1:15:34 PM UTC-6, Tom BravoMike wrote:
Yes, read the same article. My guess is that the "expert" reply to the question was by a power pilot who hasn't landed a glider. His answer only covered an asymmetric deployment of flaps as a low probability of occurrence (hence low risk), not the other changes that occur to us glider guys. Since we are landing dead stick, we don't have the same options at low altitude as a power guy - namely, applying power. Messing with the flaps during landing base and final legs changes the stall speed, as well as provides another input to attitude which has to be compensated for. My answer to the question was "no, I don't change flaps during base or final phases of landing."

My DG FM says to set flaps to L or +8 abreast touchdown point on downwind. That's what I do, and then don't touch them again until stopped.

Did the same with my ASH 26E, except after landing, going to negative flaps for rollout control. That isn't necessary on the DG, so the flaps stay at +8 or L.

This lessens the workload during that critical phase of landing. After turning final, stick, rudder, air brakes are all that are necessary to get to aim point.

Eric B.
8E

[jfitch]

I have no problem adjusting the flaps in the pattern. You do need to be cognizant of how your glider behaves by trying it (frequently, to refresh memory) at altitude.

But another important distinction is that AS gliders of the last several decades have a different flap system than other manufacturers. As the flaps are moved from thermalling to landing position, the inner panels come down further, while the outer (aileron section) comes back up. This has many advantages, but also some differences in characteristics compared to others.

In my opinion, if changing the flaps in the pattern results in a stall, you were flying waaayy too slow.

[Moshe Braner]

- same is true for spoilers. Moreover, deploying spoilers increases the
stall speed, while adding more positive flaps reduces the stall speed.
Some glider have only flaps, no spoilers, not a problem. Too many myths
about flaps. Know your glider.

[Tango Eight]

> What is your experience/opinion?

Start with the POH, not some poorly sourced article on the internet. Doubly so for an ASW-20. What's it say about landing flaps?

T8

[youngbl...@gmail.com]

The early ASW20 had a different flap configuration than later models, my 20 had those beautiful Jesus flaps that gave the ship a bad nickname and eventually people came to respect those flaps, I wish my 27 had those flaps. The sister ship to mine was involved in a deadly crash shortly after receiving the ship and it was a classic stall spin while landing as the Jesus flaps were extended while turning at a low altitude. The cause was not the flaps but the slow speed that created the stall. Landing that ship in that flap configuration was delightful, both Eileen and I flew that ship and never had any problem, what we did not do is go to that Jesus flap setting until we were on final and I do the same thing today with the 27. Landing flap configuration one or two for me is automatic in the pattern, only going to full on final satisfies my need on all occasions, even when landing out. OBTP

[George Haeh]

In the 20C (no Jesus flaps) and 27, it's best to wait until on final and the aim point is between your toes.

While the 27 does not have Jesus flaps, the maximum Landing flap speed is 80 kt. Landing flap, full spoiler and 70 kt brings you down at about a 14° slope as I saw in an IGC file.

[Bill Tisdale]

On Thursday, June 15, 2023 at 1:02:17 PM UTC-4, George Haeh wrote:
> In the 20C (no Jesus flaps) and 27, it's best to wait until on final and the aim point is between your toes.
>
> While the 27 does not have Jesus flaps, the maximum Landing flap speed is 80 kt. Landing flap, full spoiler and 70 kt brings you down at about a 14° slope as I saw in an IGC file.

I have no problem adjusting flaps up or down in the traffic pattern. But then again, I fly a Schweizer 1-35. Just don't raise the flaps from 30degree to zero, that's one big sink rate.
Bill