Open-Door Policy

Flimsy doors and windows are prone to popping open, but we still have to fly the airplane.

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The Cessna 150 I first soloed had a time-between-window-openings of about three hours. My instructor and I had suffered the event a couple of times on my way to soloing at-as luck would have it-about nine hours. Sure enough, as I lifted off the runway on my second touch-and-go, the window on the “far” side of the 150s “cabin” decided it was time I had some fresh air and noise. As if I needed another challenge.

What I really needed was three hands: one for the yoke, one for the throttle and one to grab the window latch. Not capable of all three tasks, I climbed away from the runway to what I considered a safe altitude, loosened my death grip on the throttle, reached over, closed the window and latched it. After an otherwise uneventful circuit, I landed to pick up my instructor, who was still laughing. For all I know, he still is.

Since then, doors and windows of other airplanes Ive been flying have popped open from time to time. Aside from the rushes of wind, noise and adrenaline, there havent been any ill effects. Thats not to say an open door or window is always a non-event. Depending on the airplane, an open door can disturb the airflow over the horizontal tail, setting up an oscillation in the yoke. Other airplanes, including those with gull-wing doors, present different problems, including the possibility of the door departing the airframe, perhaps damaging the tail on its way to wherever departed doors go. Depending on the circumstances, an open door or window on a pressurized airplane can be a bona fide emergency.

In all such events, however, we still must fly the airplane. Whether its a gentle climb to pattern altitude, an emergency descent from the flight levels or something in-between, the burden of handling the event is on us.

Each year or so, someone forgets this maxim, or is unable to follow through and prangs an otherwise perfectly good airplane. Heres such a tale, one which resulted in a fatality and serious injury.

Background

On September 3, 2008, at 1553 Central time, a Socata TB-20 Trinidad was substantially damaged after an impact with terrain and post-crash fire near Cassville, Wis. Visual conditions prevailed. The commercial pilot sustained serious injuries; and the private pilot was fatally injured. The flight originated at the Dubuque (Iowa) Regional Airport (DBQ) and was en route to Wisconsin when it diverted to the Cassville (Wis.) Municipal Airport (C74).

According to the surviving pilot, who occupied the left seat, the right cabin door opened in flight after an unknown amount of flight time. The right-seat pilot held the door closed and the left-seat pilot diverted to C74, which is about 21 nm northwest of DBQ. The left-seat pilot subsequently stated the approach to C74 “didnt look good,” so he performed a go-around. During the go-around, the right cabin door opened and the airplane rolled to the right. The left-seat pilot stated he “lost control” of the airplane and did not know whether the airplane stalled. He did not know what caused the door to open in-flight.

Investigation

The main wreckage came to rest between two motel cottages about 500 feet from the approach end of the runway at C74. The airplane and the two cottages were consumed by fire. The landing gear was extended and the flap jack-screw position equated to a 10-degree flap extension. The 1997 TB-20 was equipped with gull-wing doors articulating around a hinge on the top of the fuselage.

The right-hand door hinge assembly was attached to the remaining fuselage and door. Only one of four door hook assemblies was found. The door hook assembly was separated from the door and within the main wreckage. Two of its mounting screws were still attached to a portion of the remaining door. Each screw had three washers in place. The door hook assembly spring was in place.

Only one of four access door mechanism latching ring assemblies was found. The latch ring was of metal construction and fracture surfaces within the assembly were granular in appearance, consistent with overload. According to the airplane manufacturers representative, the accident airplane was equipped with steel door hook assemblies during manufacture. The manufacturers representative also stated the TB-20 airplane had not been flight-tested with an open cabin door. The Pilots Information Manual, Section 2, Limitations, Use of Doors, states, “Flight with doors open and ajar is prohibited.”

The two pilots were enrolled at a universitys aviation program; the accident airplane was operated by the university, which operated four other TB-20 aircraft. The other TB-20s door hook assemblies were checked using a magnet to determine if they were made from steel. All of the airplanes were reportedly equipped with steel door hook assemblies. The universitys maintenance director stated there were no previous reports of cabin doors opening in flight on any of the TB-20s.

A query of FAA Service Difficulty Reports for TB-20 airplanes on November 25, 2008, yielded 34 records. Only one related to a cabin door.

Probable Cause

The National Transportation Safety Board determined the probable cause of this accident to include: “The left-seat pilots failure to maintain control of the airplane during a go-around and the inadvertent in-flight opening of the cabin door for undetermined reasons. Contributing to the accident was the distraction of the door opening.”

Well never know why the door re-opened during the go-around-did the right-seater lose his grip?-but it certainly came at a bad time. Its possible the full-power configuration and nose-up attitude of a go-around resulted applied greater opening force on the door. Regardless, its pretty clear the left-seat pilot was fairly rattled by the suddenly open door, along with the resulting wind and noise.

Its easy to say “fly the airplane” in such a circumstance, but thats exactly what we need to do. Even with the rush of wind and noise from the full-power engine, the basics should get us through: Apply full power, pitch up to a climb attitude, apply right rudder to overcome torque, retract the gear and flaps, establish a climb and enter the traffic pattern for another attempt.

We shouldnt be panicking over distractions like open doors, crying babies, nagging spouses and even mechanical problems. Instead, these events should be thought of as opportunities to demonstrate how good we are.

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