Find it very hard to land this bird.

[FlyingMonkey]

On 10/5/2023 at 4:48 PM, Tom Baker said:

Flight Design's chief flight instructor back then stated that start with 15° flaps for landing, and after that your flap setting should not be greater than the hours of experience you have in the airplane. I don't know that I would go that far, but it is not a bad rule of thumb.

I have made no secret that I prefer slower approach speeds and higher flaps settings for normal conditions, but I think this is excellent advice.  The higher flaps settings are much harder to land well, and I remember having a sense of dread moving that flap lever beyond 15 when I had low time in the airplane.

I don’t think there’s a compelling need to use flaps at 30 until a pilot has a good comfort level at 15.  I even like the hours rule of thumb you cited.

[Anticept]

Hey all, so one of the things I never thought about but recently realized while discussing with a glider pilot:

It is entirely possible to be at an airspeed where there is insufficient lift generated to hold altitude, but also have insufficient pitch authority to be able to raise AoA high enough to actually cross critical AoA and stall (full aft stick). While in this condition, the entire length of the fuselage and underside of the wings are presenting a relatively large cross section to the wind and are extremely draggy, but you are not stalled.

This is what the mushing actually is: High nose but still sinking, and CTs have a HUGE mush zone at flap settings 15 degrees and greater.

Training traditionally makes us very aware of stalls, the alarms and the feelings just before it actually stalls. But mushing is not a stall! You do not get warnings about mushing like you do with stalls but you can still slam in because you can't compensate with pitch!

While mushing, drag is so high that either altitude or airspeed are going to be lost extremely rapidly until either contact with the ground, or an actual stall occurs That's why CTs can be so difficult to land and the high drag of mushing require so much power to regain airspeed initially.

With most trainer aircraft, you can't really mush unless loading is at the extreme forward CG. I can get a 172 to do it in certain loading conditions that are in allowances but it takes effort (easier to do if it's one of the retrofitted ones with a bigger engine). Glider pilots are also aware of mushing, and use it as a sort of air brake.

To reduce mushing tendencies, you have to push the CG as far aft as possible, this supplements the downforce by the stabilator and gives you more control authority back since you don't have to pull as far aft for the same AoA, and will make the airplane more docile when landing.

I have been aware of the mushing tendency of my CT for years and have taught other pilots and instructors to be watchful of it, but now that I am aware of the true cause, I can explain it much better. I think everyone should be aware of it and learn to recognize the signs of mushing. I know that a mush is about to start when I have to suddenly and more rapidly add pitch to hold altitude (like just above the runway).

You can practice mushing by loading forward CG, and going out and flying slow with 15 or more flaps in, fly as slow as you can, and watch your vertical speed (and ball, don't spin!). There will be a point that you have to pull back more and more rapidly just to hold altitude, and then you can't hold altitude at all and are out of aft stick travel. You are now mushing. Add a little bit of power and try to hold airspeed and altitude... it's quite difficult because as you add power, you're generating more lift from the airstream immediately and you might even find yourself suddenly with enough pitch authority that it DOES stall!

Because the tendency to mush depends on weight and CG, there's no magic airspeed number here. You just have to practice recognizing when the mush is starting, and in response, add a good bit of power to counter it if you are not ready to touch down!

Or if you don't like the mushing, you'll have to work through your avenues to get weight added further back somewhere. One day I flew home unaware that I had a tailfin full of water and was really confused as to the flight and landing behavior... it was better behaved than usual, requiring a lot less trimming, but that's still very abnormal so I investigated anyways, and that's when I discovered the tail full of water! Drain hole got clogged and it rained overnight.

[Madhatter]

As a glider pilot I haven't heard this, but I'm sure if I was into dog sledding I would

 

[Anticept]

Excerpt from Stick and Rudder by Wolfgang Langewiesche

[Madhatter]

A word of caution. When I did my research and flight testing with vg's on the wings of the CT with different % chords with over 100 stalls in all configurations there was one and only one benefit.  When at minimum power at slowest speed and holding altitude,  when it stalled it was fairly docile. Without vg's the stall was very abrupt with a wing drop requiring rudder action. I don't think I would want to play this game close to the ground. Sailplane performance is completely different than a CT.

[FredG]

My CTsw stalls with flaps 0, 15, and 30 degrees with ample warning, no wing drop, and just relaxation of the stick to get the wing flying again.  Same with stalls in slips and stalls in a coordinated turn.  I have 1200 hours in the airplane, but I am no Bob Hoover.

[Madhatter]

2 hours ago, FredG said:

My CTsw stalls with flaps 0, 15, and 30 degrees with ample warning, no wing drop, and just relaxation of the stick to get the wing flying again.  Same with stalls in slips and stalls in a coordinated turn.  I have 1200 hours in the airplane, but I am no Bob Hoover.

For a normal stall, yes but not in the scenario I mentioned . Not in over 20+ times I did it with 15 degrees flaps. If yours doesn't good for you. 

[Towner]

5 hours ago, FredG said:

My CTsw stalls with flaps 0, 15, and 30 degrees with ample warning, no wing drop, and just relaxation of the stick to get the wing flying again.  Same with stalls in slips and stalls in a coordinated turn.  I have 1200 hours in the airplane, but I am no Bob Hoover.

X2

[GrassStripFlyBoy]

My 2 cents on stalls , there is significant difference when the airplane is solo ~ 900 lbs, and gross 1320.  Solo & light it's very mild, load it to gross and much different.  

[Madhatter]

I think you are missing the point. This maneuver is to hang it on the prop already in deep stall with no aileron control effectiveness only rudder at this point. IAS at 20 kts with vg's,  25 kts without vg's.  When the lift collapses it is abrupt. Anyway this was not enough of a reason to have vg's on the wings.