Today’s lesson was all about stalls and how to recover from them.
What is a stall? Simply stated it is when the angle of attack of the wing exceeds the critical angle of attack. Therefore, the airflow around the wing becomes disrupted and the wing no longer produces sufficient lift and the plane will fall.
It is therefore a crucial part of the training to be able to recognise a stall and recover from it. There are different types of stalls and today we’ve practiced power-off stalls with and without flaps.
Once in the air at a safe altitude to practice stalls (around 2,500 ft AGL), we reduced the speed by pulling back the throttle to idle while maintaining the altitude. The plane started to slow down and in order to maintain the altitude, the angle of attack (AoA) had to be increased more and more. The aim for me was to recognise the stall and feel how the plane behaves and what the plane does when the stall happens.
On many aircraft there is a warning horn when the plane is about to stall. On the CTLS (the plane I’m flying) the angle of attack is indicated on the EFIS display as a vertical color-coded tape with green, yellow and red areas. Once calibrated, critical angle of attack will be indicated with the pointer positioned in the red area of the tape (see pictures below)
There are also other signs when the plane is about to stall or when the plane is stalling.
Recognition of Stalls
- Warning Horn
- Loss of Directonal Control
- Buffeting (aircraft dependent)
- Nose Drop (aircraft dependent)
Recover from stalls
So, now that I felt what it’s like when the plane stalls, I needed to learn how to recover from it. The CTLS is a very stable aircraft, therefore when its stalls, it doesn’t roll left of right but stays perfectly leveled. I could see that the plane was falling by looking at the PFD (Primary Flight Display) but I could hardly feel it.
Below are the steps to be done in order to recover form the 2 stalls we’ve practiced:
- Recovery from a fully developed ‘clean’ stall (no flaps – nose down, full power, climb attitude)
- Recovery from a fully developed stall with 2 stages of flap – (nose down, full power, climb attitude, wait for positive rate of climb then flaps away in stages)
Prevention of Stalls
Although it’s good to know how to recover from a stall, it’s best to avoid them as much as possible.
- Know that exceeding critical Angle of Attack is preceded by warning signs
- Observe ‘Sterile Cockpit’ rule during Take-off and Landing
- Practice Stalls – Sometimes recognition signs are subtle
- Maintain coordination on all turns – Rudder is your friend
- Overshoot Base to Final Turn – Make a Go-Around
- New aircraft type checkout should include stalls