Sometimes it’s an on-board gadget that gets you. Sometimes it’s the absent accessory that does the damage. There are even cases where it takes one of each to get the pilot in trouble.
Gadgets long identified as culprits in accident cases are still doing their damage to property and pride. Also exacting its traditional toll is a lack of training in how to cope with known hazards associated with accessory abuse or non-use. For example, in the absence of an aircraft pitot tube cover—available for about $10 by mail order—blocked pitot tubes have caused numerous accidents requiring major repairs to aircraft and, in one case, presumably to a fence in Michigan.
Did your training include learning how to deal with a failure to remove your aircraft’s pitot cover before flight? Did training teach you what to do if you ever took off with an undetected pitot blockage? The drill is to learn how to abort safely, or if too late for that, continue the takeoff without reference to the airspeed indicator.
Learning to recognize the control pressures and aircraft responsiveness indicative of various airspeeds, and the aircraft performance produced by known combinations of power and pitch, will help you maintain situational awareness if faced with anomalous indications of a faulty airspeed indicator, allowing you to complete a safe and undistracted takeoff, traffic pattern, and landing.
On August 5, 2013, a pilot of a Cessna 182 was taking off from Mackinac Island, Michigan. “The pilot reported that during the takeoff roll the airplane visually appeared and felt to be accelerating normally, but the airspeed indicator never increased above 40 knots,” said a National Transportation Safety Board accident summary.
Halfway down the runway, the pilot tried to abort the takeoff, but “the airplane was skidding on the wet runway. The pilot was unable to stop and went off the runway and collided with a wood fence, which resulted in substantial damage to the right elevator.”
Examination revealed a pitot tube “filled with debris. According to the operator, the airplane was not equipped with a pitot tube cover.”
Probable accident cause: The pilot’s delayed response to abort the takeoff, which resulted in an excursion and collision with a fence. Contributing to the accident was the pilot’s failure to check the pitot tube for debris during preflight.
Another occasional cause of runway overruns and excursions finds its way into accident reports when a pilot attempts to take off with a control wheel lock still in place. Usually, two safeguards help make this a rare event. One is the design of many locks, which requires the lock to be removed before an ignition key can be used to start the aircraft. The second safeguard is the checklist, which requires that flight controls be confirmed free and correct before takeoff.
But control wheel locks also come up missing on occasion. What the pilot does in that case can quickly become the first link of an accident chain of events.
Preflighting for an evening flight on August 2, 2013, a Cessna 172S pilot noticed that the control lock was not installed. But “while searching for the control lock he located a ‘straight pin’ in a seatback pocket and installed it,” according to the NTSB.
The pilot remembered to remove the straight pin before flying to the destination airport in Portsmouth, New Hampshire. But on the return flight, it was overlooked.
“He taxied to the run-up area of Runway 34, where he performed the before-takeoff checklist but did not check that the flight controls were free and clear—for fear of having his tablet knocked off the yoke mount,” said the summary.
“After the airplane rotated it climbed to an altitude of about three feet and settled back down on the runway and bounced. Confused as to what was occurring, he added nose-up trim to assist in the climb. At this point the airplane climbed to about 10 feet, then the nose pitched downward, and the nosewheel struck the runway.” Cited as probable cause was “the pilot’s inadequate preflight inspection resulting in his failure to remove the pin he used to lock the flight controls in place of the approved control lock.”
The purpose of the devices, gadgets, and gizmos designed to be used on, or affixed to, an aircraft is to minimize the risk of flight, or make flying more efficient. Products like control locks and pitot covers perform their functions by working in harmony with standardized safety measures such as checklists. If the device is to be removed before flight, an attention-getting design provides safety margin.
Substituting an unapproved device cancels that margin. Trusting to memory about the substitution, then stepping over your checklist’s last line of defense, leaves safety to chance alone.
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