Flap deployment when?

[Guest iPilot]

I was told by my instructor that if you pull flaps during the turn and have a flap failure, you could throw yourself into a spin so he recommended full flap on late downwind. Having said that, every other aircraft I've flown in for work, Aerorescue, Surveillance Australia etc, pull flap whenever required regardless if you're in a turn or not.

 

 

[Guernsey]

Of thread but here is a thought... I extend flaps on the Sav at or below 55knots... if the whole circuit was flown with half flaps could you get a LP endorsement in this aircraft (I got HP- I guess it just gets over the line for it).

I believe that the speed requirement for LP endorsement is the aircraft's cruise speed.

Alan.

 

 

[Spin]

fOf course you can also sideslip with flap on most types if you ever need to. It is less effective on Cessnas, but very effective on a 7GCBC Citabria for example.

 

Your own instructor will give you the best advice for type and technique (hopefully).

 

David

Interesting little nugget there, the C172 is one type which positively prohibits slipping with full flap - and is probably responsible for most of the half digested opinion that holds that slipping with flap is a bad idea on all types. Contrary to popular belief it is nothing to do with strain on flap tracks/hinges, but is due to what Cessna calls the possibility of a cyclical nodding motion (the flap can partially blanket the horizontal stabilizer at certain attitudes). Fortunately RAA instructors that I've dealt with seem more comfortable with slipping than many of their GA counterparts who seem to want to fly everything as if Messrs Boeing and Airbus were the manufacturer.

 

 

[sfGnome]

...a good landing is always preceded by a good stable approach down final...

Oh ain't that the truth! Wish it hadn't taken so long to work it out.

 

 

[naremman]

One essential consideration in this process is taking the flap extension speed into account. In a lot of aircraft airspeed on the downwind leg exceeds Vfe, which means airspeed has to washed off at some stage before flap gets thrown out.

 

What my ex Army instructor taught me many moons ago on a C172 has stuck with me to today. Clear the turn, apply carb heat, commence base turn, throttle to idle (cos if you fly bigger iron later gear warning will activate should the U in BUMFH be missed), maintain nose on the horizon, rollout onto base leg, check inside Vfe, 20 degrees flap, advance throttle to 1700 rpm, and amazingly the trim setting on downwind is pretty close to where you need it on base leg. Any attempt to put flap down over Vfe triggered a veritable explosion from the right hand seat!! Students sensitivities were given scant regard then.

 

Making the transition to RAA aircraft the same technique was employed for both the J160 and Foxbat. The J160 when solo has about 20 knots to wash off from downwind before flap extension, and is certainly quite slippery when clean.

 

The various models of Cesna 172s that I have flown have quite significant differences in Vfe, and flap settings. The D model I learnt on had a Vfe of 80 knots with 40 degrees of flap. I then graduated onto a M model, and currently own one, with a Vfe of 85 knots and still with 40 degrees max flap, which I really like. The newer variants have the preselect flap, with the first 10 degrees able to go out at 110 knots, but are limited to 30 degrees of flap. Certainly a good reason to check the POH to make sure the right numbers are ingained into the grey matter.

 

 

[kaz3g]

I like the idea of putting the first stage of flap out after im on base, and have the aircraft set up at its base speed....in my 170, its 70knts on base, then trim for the pressure. Then once the flaps come down, even with forward pressure on the control column, i dont move the trim. If the trim is still 'nose up' for that previous 70 knts, u dont have to fight against the trim during the flare..... My 2 cents...... :D

Hi Foxy

 

I'm an old glider pilot and I like to either be trimmed neutral for final approach or perhaps a little bit nose-down in case of gusts. I'm approaching at about 45 knots and don't have much inertia in the Auster.

 

I fly a fairly tight circuit and try to slow it down late downwind from around 100 knots to 55 knots. I set up for 50 on base with one stage and then 2-3 stages on final as I bleed off a bit more speed. I approach high and lose most of it after turning final so if the noise stops I can still squeek in. If I need to lose more, the Auster side-slips really well.

 

If anyone is in the circuit behind me, I usually give them warning of my slow circuit speed so they can go a bit wider and avoid being jammed in behind me by the time I'm turning final.

 

kaz

 

 

[djpacro]

... do you hold the control column between your knees ....

David!!! It is not a control column, it is a joystick!

[Guernsey]

I like that Kaz, it brings back memories of the J1B I have flown.How does a lady manage that flap deployment lever designed by a committee on the Auster ... do you hold the control column between your knees and use boths hands to pull that lever down or do you have a more elegent tecnique .

 

David

Eat more and put on weight.

Alan.