Landing with flaps- questions

[tboltsg]

Hi fellows,

Been trying out landing with flaps lately. Initial intend was to slow down landing speed of the aircraft. Notice the followings

1. There seemed to be no significant difference in the stall speed of the model. (flap fully deployed angle is abt 55 degrees)-Is this normal? or am I missing something.

2. The aelirons control seemed to be sluggish when flaps is deployed. Is this normal? and how to counter this?

3. There is a tendency to tip stall when flaps are deployed- Is this normal? and how to counter this?

4. Should the motor rpm be higher as compare to landing without flaps?

Appreciate any explainations or share experience with regards to using flaps for landing.

Thanks in advance
TB

[chiadennis]

What plane are you planning to use flaps on?

[Blackite207]

Your flap is extended too great an angle. I suggest that you reduce the angle to 30deg. Currently your 55 deg is no doubt stalling that section of the wing.

[Blackite207]

When flaps are deployed there is a tendency to baloon the aircraft so if you have a mixer, mix some down elevator with flap. you will need some power for landing as flaps increase lift ( hence the baloon effect ) but also drag.
With the lower airspeed, you may experience eleron effectiveness so mix some rudder in aswell.

[joe yap]

Hi fellows,

Been trying out landing with flaps lately. Initial intend was to slow down landing speed of the aircraft. Notice the followings

1. There seemed to be no significant difference in the stall speed of the model. (flap fully deployed angle is abt 55 degrees)-Is this normal? or am I missing something.

2. The aelirons control seemed to be sluggish when flaps is deployed. Is this normal? and how to counter this?

3. There is a tendency to tip stall when flaps are deployed- Is this normal? and how to counter this?

4. Should the motor rpm be higher as compare to landing without flaps?

Appreciate any explainations or share experience with regards to using flaps for landing.

Thanks in advance
TB

Flaps are used to steepen your take-off and approach. Usually, 30 degrees is the maximum defelction for most planes, other than gliders. Flaps do reduce the stall speeds, by increasing the effective range of angle of attack. But do remember that the wings' critical angle of attack will be reduced and you'll need to fly with the plane's nose pointing a little downwards. You may have encountered tip stalls caused by ailerons instead of wing stalls.

Ailerons sluggishness is normal during flap deployment, and most pilots are taught to use more rudder. You can always program rudder mixing to compensate this at take-offs and landings.

The tip stall tendencies could be linked to the excessive use of ailerons, due to the fact that they become sluggish with flaps down. Like said before, use more rudder at lower speeds. You can also minimise tip stall by programming differential aileron movements.

With flaps down, the landing pattern should be steeper than with them stowed, so if done correctly, the motor speed should be the same. But if you approach with a shallow landing gradient with flapd down, you'll probably need higher motor speed to overcome the extra drag.

[tboltsg]

Hi blackite & joe,

Many thanks, for sharing your knowlegde on using flaps, will reduce flaps angle to abt 30 degree and try out the procedures recommended.

aside to chiadennis-flaps used on avenger.

Cheers
TB