The Unknown in the Machine

What evil lurks in the heart of an airplane?

In December 1996, a pilot and his companion checked out a Beech T-34 Mentor from the flying club at the Memphis Naval Air Station in Millington, Tennessee. They departed at about 4:15 in the afternoon on a 300-nautical-mile trip to Bay St. Louis, Mississippi. By the time they approached the Gulf Coast, it was dark.

Several witnesses reported seeing the airplane—or at least its navigation and anti-collision lights—flying ­westbound “oscillating both vertically and laterally” and then “rotating about the longitudinal axis” before pitching nose-down. The pitch of the engine sound was heard rising, then there was a sound like an explosion, followed by that of an impact with the ground.

The pilot had not been in contact with any ground station, but Houston ATC radar recorded a target that was most likely the T-34. Squawking 1200, the target flew at 3,500 feet for 12 minutes then began a gradual descent. After two minutes, it abruptly climbed from 3,200 feet to 3,600 feet in 12 seconds, then descended 1,500 feet in the next 12 seconds before disappearing from radar. During this time, the direction of flight was generally south- or southeast-bound, not westbound, as witnesses reported. The discrepancy was unexplained.

The wreckage of the T-34 was found about two-tenths of a mile south of the location of the last recorded ­transponder code, in an area with “minimal ground-reference lights.” It appeared that the right wing had separated in flight, followed by the empennage surfaces.

The National Transportation Safety Board attributed the accident to “the noninstrument-rated pilot’s intentional operation of the airplane with known…inoperative attitude indicator and directional gyro…with an estimated time of arrival after official twilight.”

Pick up a copy of Peter Garrison’s book here.

This analysis had quite the stink of bureaucrat about it. There is no legal requirement that an airplane be equipped with attitude and directional gyros to be flown at night. The pilot knew that the vacuum-dependent instruments were inoperative. Navy Flying Club rules required airplanes to be instrument equipped for night cross-country flights, but the nonpilot desk clerk who released the airplane may have been unaware of that rule or its significance, or unaware of the condition of the particular airplane, or both. The pilot too may have been unaware of the rule. At any rate, the NTSB’s conclusion was tantamount to saying that the airplane crashed because it was in violation of a rule of the Navy Flying Club.

A few years after this accident, ­several wing-spar failures in T-34s led the FAA to ground the entire civilian fleet until spars were either reinforced or replaced. At the time of this accident, however, concerns about structural integrity of the type—which was ­manufactured from 1953 to 1959—had not been raised. The accident airplane had flown nearly 15,000 hours. The NTSB’s description of the structural failures makes no mention of metal fatigue and the metallurgical expertise of the investigator who reported “­overload ­failure” is not recorded.

It is possible that the ­38-year-old pilot, who had almost 500 hours total time and 164 hours in the T-34, became spatially disoriented, but it is not especially likely. It was evidently a VMC night with a partial moon, there were towns nearby and the T-34 has a greenhouse canopy that provides a clear view of the surroundings in all directions and minimizes the likelihood of disorientation. The environment was rural but not unpopulated; there were towns, roads and highways below, including Interstate 59 and U.S. Highway 11. The pilot had been properly signed off by the flying club’s chief instructor for night flight and had logged almost five hours at night in the past month.

The NTSB evidently did not ­consider the possibility that the “oscillating” flight reported by ­witnesses was deliberate. The pilot may have been having a little fun in the aerobatic trainer, perhaps even essayed a barrel roll—which would be consistent with a sudden altitude gain—dished out and overstressed the right wing in the recovery.

To the NTSB, this accident ­illustrated the dreadful hazards of ignoring an officially mandated ­minimum equipment list. It may, alternatively, have demonstrated that airplanes, especially old ones, can have hidden defects. An accident that had taken place almost exactly 24 hours earlier in Alabama illustrated the danger of latent defects. It also illustrated the fact, which needs no ­illustration, that some things are easier to do in daylight.

Editor’s note: This article is based in part upon the NTSB final report for a given accident. The intention is to bring the probable and contributing causes of these accidents to our readers’ attention, so they can learn from them and apply them to their own flying.

The 2,400-hour pilot, 41, of a Piper Cherokee Six died while ­attempting a night dead-stick landing at an unlighted rural airport. The account of his final minutes is harrowing.

The airplane’s last annual ­inspection had occurred eight years earlier; since then, it had flown only 30 hours. The pilot had been engaged to perform an annual inspection and then ferry the airplane to its new owner in Tampa, Florida. The seller reported that he did not see the pilot perform an annual inspection, nor even look into the cowling. He did, however, drain the tanks and refuel the airplane.

Twelve minutes later, the engine began to run rough—and then quit.

The Cherokee pilot told the controller, “I’m experiencing major trouble. I need the closest airport.”

The closest airport was North Pickens (3M8) at Reform, Alabama, 10 miles away. The pilot reported that he had slowed to 80 knots and was descending. There was a hitch: North Pickens had runway lights, but they weren’t turned on. There was also no rotating beacon. The controller, who was evidently quite familiar with the area, took steps to have someone go to the airport and turn the lights on and, in the meantime, described the surrounding landmarks to the pilot. The efficiency of the controller was matched by the coolness of the pilot, who reported that he was at 5,000 feet descending about 800 feet a minute.

Eight minutes after the pilot first reported his situation, the controller told him the airport was at 12 o’clock and two miles. The pilot replied that he was at 2,000 feet. “I still don’t have anything in sight. There’s a Texaco station or something right in front of me.”

The controller said that the Texaco station was close to the airport. It is, in fact, about 3,000 feet due west of the threshold of Runway 1.

The controller told the pilot, who was looking at the lights of the tiny crossroads town of Reform, that the runway was now off his left wing. “Sure wish I had some power,” the pilot remarked. He now knew he had missed the airport and his time was short. “I’m going for the dark spot that’s just south of a major route, looks like a highway, through the ­center of town.”

The pilot of a Baron who was on the frequency relayed a final message from the Cherokee pilot. “He was going to stall it into the trees.”

The controller learned from the sheriff that the airport actually did have recently installed pilot-­controlled lighting on 122.9, and he passed the information on to the Baron pilot, who attempted to turn on the lights, without effect. A few minutes later a car arrived at the airport, and shortly after that, the lights came on.

The cause of the power loss was failure of the coils of both magnetos, which broke down as they heated up. Even if the pilot had performed a thorough preflight inspection, or a full annual inspection, he would not have detected the problem. The FAA guidance document for annual inspection, AC 20-106, requires only external inspection of magnetos.

But if he had delayed his takeoff until the following morning, he would have made the runway at Reform.


New to Flying?


Already have an account?