Private Pilot Flight Training and Instruction
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Aborted Takeoff
(once is enough)
It is all too common to have a seat slide back during initial
takeoff acceleration. For this reason the seat security should
be part of the takeoff checklist as well as doors and windows.
Have the student accelerate for take off and pull the power off
just before lift off. Do not apply the heavy braking that might
be required in a real situation because of possible damage to
the nose gear or tires. The idea of rejecting the takeoff with
a resulting accident off the end of the runway is not pleasant.
Running off the end of the runway while decelerating is better
than colliding with the ground after becoming airborne.
Training works provided you remember to carry the lessons learned
into the situation. The takeoff is one of the highest risk phases
of flight. Time is not, necessarily in your favor, at 60 knots
you are going 100 yards (a football field) every three seconds.
At 80 knots 200 yards in five seconds. Regardless of the runway,
you should pre-decide an abort point for every takeoff. Beyond
that abort point you are committed to takeoff. Due to potential
hazards the aborted takeoff is best not practiced to excessive
limits. Simulate but doing the real thing can be dangerous or
hard on the aircraft. Once airborne the reason for aborting becomes
even more complex and dangerous. Quick thinking and analysis is
needed prior to liftoff. Hitting something while skidding off
the runway can be far less damaging than going into an off-airport
area. Use 150% of the POH landing roll distance for your required
abort/stop distance.
The sooner the abort decision is made the more chance of success.
On a short runway abort before lift off. Heavy braking is hard
on the aircraft but it will probably be required in an aborted
take off. If you have full power you may be better off not to
abort. Abort problems often occur when there is a conflict of
authority. If airborne, continue if door pops open. Return to
land and close door. In the event of fire or smoke be prepared
to evacuate.
Takeoffs are successful so often that we fail to prepare for
the one failure. In fact, we will never be fully prepared for
rejecting the takeoff unless we learn what to do before it happens.
We must pre-decide what aircraft performance we will require over
the distance remaining. We must relate what we have commonly experienced
in acceleration and speed with what is occurring at a given moment.
If the performance is not there, we must immediately pull the
power and mixture, apply brakes up to the point of a skid but
not into the skid. We must maintain a straight line with the yoke
pulled all the way back to give maximum weight to the main wheels.
The aborted takeoff, often called the RTO or rejected takeoff,
is a not too common occurrence. It can occur because of a seat
sliding back, a clearance, a door opening, etc. Airlines have
RTO (rejected take off) 1 out of 2000 takeoffs more often because
of indications of failures rather than actual failures. You must
make a book determination that the runway is adequate for the
aircraft and conditions. A conservative 2.2 x book figures is
a good risk management margin for takeoff. A 10 kt tailwind will
double the book figures without any margin. If you are half way
down the available runway and performance is not as expected,
abort. Some abortions occur because the pilot has not correctly
anticipated how density altitude and changing wind conditions
along the runway. Winds can and do vary along the length of a
runway.
If you can reduce your speed by half before impact with an object
you will decrease your force of impact by 75%. Hit any objects
while turning with the wing or tail to utilize the ability of
collapsible material to absorb impact. Your survival is more important
than the insured condition of the aircraft. At impact be sure
electrical system is off.
An aborted takeoff due to engine failure should include immediate
power reduction, mixture to idle/cutoff, and heavy braking on
runway heading with a ground loop as required to avoid obstruction
impact. Any engine failure after takeoff should be followed by
setting nose glide angle and trimming (3 additional full turns
from climb trim) for best glide. Select the best available within
60 degrees of heading and wind direction. Pull throttle and mixture
to full off since numerous fatal accidents have been caused by
sudden and unanticipated power resumption. Shut off the fuel.
Avoid obstacles and use full flaps prior to ground contact at
minimum speed. Turn off electric master when flaps are down. Unlatch
doors.
At some later point in the training a no-airspeed-indicator
takeoff should be made. The student will be required to visualize
the nose attitude that gives a desirable airspeed. Requiring visualization
is good for the student because they must have in their mind a
picture of what they are doing. With the airspeed and perhaps
other instruments covered makes the student feel and hear aircraft
performance.
Written by Gene Whitt
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