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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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