Flight Training - August 2011 - 24

ACCIDENT REPORT

By Dan Namowitz
LANDING rule of thumb: A 10-percent increase in groundspeed equals a 20 percent increase in ground roll.

WHEN TO REJECT A TAKEOFF

SOMETHING DIDN'T 'FEEL RIGHT'

hat’s your working rule about how and when to reject a takeoff? If you recognize that you have a problem early enough, there’s usually still time to avoid trouble. Knowing that, a pilot should give the possibility of aborting the takeoff lots of respect. When was the last time you actually practiced an abort, especially one initiated at—or even after—rotation or liftoff?
An aborted takeoff can be a necessarily spontaneous maneuver that doesn’t always end with smiles and high fives. Actual aborts can result in blown tires from severe braking, or an intentional groundloop to avoid runway end lights, obstructions, ditches, or even another aircraft suddenly appearing. After liftoff, an abort—say, because of a bird strike— brings an entirely new set of risk factors that must be weighed against the option of continued flight. Complicating the issue is the fact that not all distractions on takeoff require aborting the departure. In many aircraft, a door popping open during the takeoff roll may require little more than putting it out of your mind until you can climb to altitude, level off, and deal with it. Failure of an instrument such as an airspeed indicator on takeoff has also led pilots into numerous accidents. The National Transportation Safety Board cited the pilot’s delayed decision to abort the takeoff as the probable cause of a Cessna 177B accident in Middlebury, Vermont, on August 1, 2010. Two minor injuries resulted from the mishap. “According to the pilot, he performed a runup and proceeded to the departure end of the runway. He applied full power and began the takeoff roll. With the airplane about halfway down the runway, the pilot realized that the airplane was not developing as much airspeed as he expected. As the airplane approached the end of the runway, he decided to abort the takeoff,” said the accident summary. The airplane ran off the end of the runway. The report added that “the pilot noted that he had forgotten to set the flaps properly for takeoff.” On the same day, a pilot distracted by a sliding canopy on his RV-8A lost control on takeoff in Carlsbad, California. The pilot was uninjured. “As the pilot attempted to close the canopy the airplane nosed over and the propeller struck the runway, substantially damaging the airplane’s firewall. The pilot further reported that the accident could have been prevented by conducting a ‘second check of proper canopy closure prior to entering [the] runway.’” The NTSB determined the probable causes of the accident to be “the pilot’s inadequate pretakeoff checks and failure to maintain control during the takeoff roll. Contributing to the accident was the pilot’s diverted attention because of the open canopy.” An amateur-built motorglider’s pilot thought that something didn’t feel right, but still continued the takeoff in his Kolb Firefly on August 4, 2010, in Lincoln, California. “A week before the accident, the aircraft was assembled by a certificated aircraft mechanic. The pilot reported that he had previously flown the aircraft one time, for about 30 minutes. During the accident flight’s takeoff roll, the pilot noticed that the aircraft did not ‘feel right,’ but he opted to continue,” said the NTSB summary. “About 250 feet above the ground the outboard right wing ‘started to flutter in a violent way’ and in response the pilot reduced engine power and aircraft speed. He then ‘lost all control.’ The aircraft impacted the ground in a field and seriously injured the pilot,” it said. The FAA’s examination of wreckage “revealed that the bolt that was supposed to attach an aileron pushrod to the out-

board aileron bellcrank was lying loose in the bottom of the wing bay; neither the nut nor the cotter pin was recovered. Examination of the opposite aileron bellcrank revealed that the corresponding bolt and nut were not secured by a cotter pin. “The mechanic who assembled the aircraft stated that he did not install cotter pins in either of the two noted bolts. The pilot stated that he did not inspect the aircraft after assembly or before the flight.” The NTSB determined the probable accident cause as “a loss of control because of the mechanical disconnection of an aileron pushrod from its bellcrank as a result of the mechanic’s failure to properly secure the pushrod attach hardware. Also causal was the pilot’s inadequate preflight inspection.” Obviously a decision to reject a takeoff will be a surprise to the pilot—a contradiction of a “go” decision made only an instant previously. Don’t make the situation worse through denial or uncertainty about the procedure for quickly and safely terminating the flight.
Dan Namowitz is an aviation writer and flight instructor. He has been a pilot since 1985 and an instructor since 1990.

ACCIDENT LOG: NTSB probable cause
August 1, 2010—Middlebury, Vermont The pilot’s delayed decision to abort the takeoff. August 1, 2010—Carlsbad, California The pilot’s inadequate preflight checks and failure to maintain control during takeoff roll. August 4, 2010—Lincoln, California Loss of control caused by mechanical disconnection of aileron pushrod from its bellcrank as a result of mechanic’s failure to properly secure the pushrod-attach hardware. Pilot’s inadequate preflight inspection was causal.

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Flight Training - August 2011

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