Dark Corner

Too often, pilots do too much to please ATC. Just say no to requests to operate at the envelopes corners.

0

Air traffic controllers have an unenviable job, at least as far as pilots are concerned. Even though theyre well-paid and do their work inside, theres too much stress, the consequences of being wrong can be too high and they have the FAA for a boss. Trying to fit a 200-knot airplane in behind one doing only 100 knots is just one of the challenges many controllers face daily; for the most part, pilots can be oblivious to whats happening on the other end of the frequency.

But pilots sometimes need to be more assertive, especially when ATC asks them to do something with which theyre not comfortable. Part of the problem pilots face when deciding whether to comply with ATC instructions and requests is the controllers presumed ability to write up a violation. Too, the very concept of a “controller” can be intimidating. Finally, most pilots understand the system and their role in it; in turn, theyll often try extremely hard to help out a controller, on the theory theyll get helped out next time.

Usually, the “pay it forward” method works out. But pilots can be too accommodating when it comes to certain requests. Immediate takeoffs for traffic, climbing into higher altitudes without oxygen and flying at or near an aircrafts operating limitations can be examples of ways in which ATC lures pilots into trouble.

Some might blame the controller for asking a pilot to get in over his or her head. But the responsibility for the flight is squarely on the pilots shoulders; it says so right in the FARs. A controller might strongly urge a certain action, but its still up to the pilot to determine if the request is one with which its safe to comply.

Its a “good thing” when both sides can negotiate a favorable outcome to a traffic or routing problem. But always trying to please ATC in search of that warm fuzzy feeling can get pilots into an operating-envelope corner we shouldnt see.

Background

On March 23, 2006, at about 1057 Eastern time, a Cessna 340A experienced an in-flight loss of control while on final approach to land at the Melbourne International Airport, Melbourne, Fla., and collided with terrain. The airplane was destroyed by impact forces and a post-crash fire; the commercial pilot and two passengers were fatally injured. Visual conditions prevailed. The flight originated about 0955, in Jacksonville, Fla.

The Cessna contacted the Melbourne tower when it was still 22 miles north. When the flight was four miles from the destination, a controller advised it to proceed westbound for spacing with a Piper Cherokee flying at 1000 feet; the flight advised it was looking for the airplane. The controller then advised the flight to turn final for Runway 9L and that the Piper was on a 1.5 mile final to the same runway. The controller asked if the flight was able to slow down, pointing out the Cherokee now on a -mile final. The flight advised it would slow down and the controller cleared the flight to land. There were no further communications from the accident flight.

A witness heard the airplane fly overhead and noted its wings “wobble[d] a couple of times,” then it turned right and dove into the ground.

Investigation

The wreckage was approximately two miles west of the airport, about on the extended centerline of Runway 9L. All major components were located at the immediate crash site. About 70 to 80 percent of the airplane had been consumed by a post-crash fire.

The landing gear was found in the down/extended position, and the flaps were up/retracted. Elevator control continuity was established from the control wheel to the elevator, and aileron continuity from the control wheel to the respective aileron bell crank.

Each of the two engines had three propeller blades. The propeller hubs of both engines had shattered, and the propellers were scattered in an arc around the wreckage. All six of the propellers had significant chord-wise scratching and bending. Inspection of the flight controls and engines disclosed no evidence of any pre-impact mechanical problems.

Toxicological samples from the pilots blood detected diphenhydramine, a sedating antihistamine commonly known as Benadryl. The drug was present at a level consistent with recent use of at least the maximum over-the-counter dose. Diphenhydramine is available over the counter for allergies and as a sleep aid. It has been shown to impair the performance of complex cognitive and motor tasks at typical doses. The FAA does not specifically prohibit the use of diphenhydramine by pilots.

Probable Cause

The National Transportation Safety Board determines the probable cause(s) of this accident to include: “The pilots failure to maintain adequate airspeed to avoid a stall during the final approach to land. Contributing to the accident was the pilots impairment due to the use of a sedating antihistamine.”

While we dont know how to evaluate the NTSBs belief the pilot was impaired from an over-the-counter medication-airplanes arent falling from the sky thanks to Benadryl-its easy to put ourselves in this Cessnas left seat. A relatively quick trip was about to conclude with an uneventful landing. Since the airport was landing to the east, were maneuvering westbound on a wide downwind, slowing in an attempt to remain close to the airport.

While still a couple of minutes from touchdown, with the airport in sight but not the traffic, a controller asks us to slow down further, pointing out Cherokee traffic we cant find. Were probably starting the before-landing checklist anyway, so we put the gear down, pull the throttles back a little bit more and re-trim to help decelerate and maintain altitude. Preoccupied with finding the traffic now on short final, we arent paying attention to the airspeed. All of a sudden-before we can bring up the power-we feel the pre-stall buffet, the right wing drops and its all a big surprise.

Mixing slow and fast traffic in the airport vicinity can be a major ATC challenge; controllers want all the help they can get and pilots are right to provide it. But not at the expense of flying in the corners of the airplanes operating envelope and losing control. Although this accident occurred at the slow end, other problems can occur at the high end, like bounces and runway overruns.

Never let ATC fly the airplane for you. If the traffic situation isnt working out, go around, request a delaying vector or find another airport and wait out the rush.

LEAVE A REPLY

Please enter your comment!
Please enter your name here