Transcript Stalling - RGS Infonet

Stalling
Stalling
• It is vital for a pilot to understand stalling
thoroughly, if he is to fly an aircraft
confidently.
The Stall
• In normal flight a
•
wing meets the
oncoming air at a
small angle of attack,
the air flowing
smoothly and
continuously over and
under the wing.
If a pilot increases the
angle of attack
slightly, the wings will
produce more lift.
• The more the pilot
•
increases the angle of
attack, the more lift
there will be, until an
angle of about 15º
At this point the
airflow becomes
turbulent, Bernoulli’s
principle no longer
applies and most of
the lift is lost- this is
the stall
Stalling angle
• The stalling angle varies
•
from one type of wing to
another, and it depends
upon the shape and
general design of the
wing.
Each wing has its own
stalling angle and the
wing will always stall
when the angle of attack
reached that angle. For
conventional aircraft it is
around 15º.
Stalling Speed
• The air speed at which an aircraft stalls
(the stalling speed) does vary. Every
aircraft has ‘pilot’s notes’ which gives facts
and figures about performance, including
the stalling speeds for certain flight
conditions.
Factors affecting Stalling Speed
• Weight – Extra weight
•
•
increases the stalling
speed
Power – The higher the
power used, the lower
the stalling speeds
Flaps- With flaps lowered
the stalling speed is
reduced.
• Ice- it alters the designed
•
•
shape of the wing section
reducing the lift and
increasing the stalling
speed.
Damaged Wings- can
reduce lift and so
increase the stalling
speed.
Manoeuvres- most affect
the stalling speed, in a
turn the stalling speed is
increased.
Attitude and the Stall
• An aircraft can stall in any attitude,
whether wings level, in a turn, upside
down or whatever. The crucial factor in
determining when a wing will stall is the
angle of attack.
Questions
Questions
Answers
• 1. c)
• 2. b)
• 3. a)
• 4. a)