For One Low-Time Pilot, A Pattern of Small Errors Proves Fatal

The 210 passed south of the traffic pattern, turned north well east of the downwind leg—the area west of the airport is residential—and then entered the pattern behind the trainer that had just turned downwind. The 210 followed the 150, gaining on it slowly, and extended its downwind until the 150 had turned final.

By the time the 210 turned base, it had drifted somewhat westward, perhaps because of the quartering tailwind or because the runway, which was on the pilot's right, was so far behind him that he could no longer accurately judge his position with respect to it. The 210 overshot the extended centerline, and the pilot turned tightly in order to re-establish himself on the final approach course. Rolling out of the turn at a very low altitude but still a mile from the runway, the 210 stalled, crashed, and burned. The pilot, a 46-year-old doctor with 200 hours, died.

The NTSB, noting that there was no evidence of a mechanical malfunction and that the airplane carried ample fuel, concluded that "...it is likely that the pilot entered the traffic pattern behind a slower airplane, and, in an attempt to add more space between his airplane and the one ahead, he reduced speed and increased airplane pitch to the point where it exceeded critical angle of attack, which resulted in an aerodynamic stall as he turned onto the final leg of the traffic pattern."

The board's analysis does not match the actual circumstances of the accident. It may have been influenced by the account of the instructor in the 150 that was ahead of the 210, who suggested that the pilot of the 210 may have slowed his "much faster" airplane to keep distance between himself and the slower 150. In fact, by the time the 210 stalled, the 150 had ceased to be a factor at all. 

FAA radar recordings show the 210 in trail behind the 150 on the downwind, with a groundspeed of about 110 knots. Correcting for density altitude, and taking into account a tailwind component of around 10 knots, this translates to a true airspeed of around 85-90 knots—not excessively slow for a 210.

The 210 maintained a fairly constant height on the downwind leg until the runway was behind it, when it began to descend. Its groundspeed increased by about five knots as it turned base, suggesting that the wind may have been more easterly than reported. The combination of its westward drift and its increased groundspeed on base carried it past the extended centerline. The pilot of the 150 described the 210 as "banking steeply" from base to final and then pitching up slightly.

The striking thing about the radar data is the rapid loss of both altitude and groundspeed—nearly 25 knots—during the turn to final. Some of the loss of groundspeed resulted from turning into the wind, but it is more difficult to account for the loss of altitude. By the time the stall occurred, the 210 was still a mile from the end of the runway, but was reported by one witness to be only 30 to 50 feet above the ground. Another witness told a newspaper reporter, "I have never seen a plane flying so close over my head."

Investigators uncovered a couple of pieces of information that seemed relevant in retrospect. A mechanic who had flown with the pilot to break in some newly replaced cylinders recalled that he had to remind him to use flaps. Photographs of the wreckage show clearly that the flaps were retracted.  With a forward CG, 30 degrees of flap would have reduced the 210's stalling speed in a 45-degree bank by nine knots. 

The pilot had failed his first private check ride. His deficiencies were in soft field takeoffs and short field landings. Both are skills requiring sensitivity to the feel of an airplane at speeds close to the stall. An instructor who gave the pilot eight additional hours of instruction before endorsing him for retest did not remember much about him, but did comment that eight additional hours after a failed private ride seemed like a lot.

The standard glidepath angle for a landing approach, used by both ILS and VASI systems, is three degrees, which requires a height of almost 300 feet a mile from the runway threshold. The pilot's excessively low altitude when turning to final hints that, possibly from force of habit or because he was too dependent on "the numbers," he may have descended with the manifold pressure setting that he would use for a normal base leg, much closer to the runway. The added drag of the steep turn would have eaten up some speed. The "slight" pitch up reported by the witness suggests that the pilot belatedly became aware of his low altitude and instinctively attempted to correct it by raising the nose.

Since there is no aim point until you turn final, flying a pattern requires some intuitive spatial sense and a feel for distances and descent rates. Novices crave precise guidelines, but they are elusive. 

The size and shape of the pattern can be adjusted to suit the airplane and the circumstances; a faster airplane overtaking a slower one, for instance, need not remain in trail, but can sidestep outward. 

A pilot extending the downwind for traffic should not begin to descend on passing the threshold; in fact, in the extreme case of a downwind leg extended three miles, the descent should begin only with the final approach. 

A pattern flown on the upwind side of the runway in crosswind conditions should be shifted outward in order to avoid overshooting on the base leg. All such adjustments are learned from experience; they cannot be readily converted into exact prescriptions.

Two rules, however, apply in almost all circumstances. One is that unless instructed to by the tower, you should not allow your indicated airspeed to drop below around 1.3 times your stalling speed until you are on short final and, as they say, "landing is assured." Luckily for the mathematically impaired, this multiplication can be performed on the ground before taking off.

The other is that you should never make steeply banked turns at low speed and low altitude.

The pilot of the 210 made several minor errors. He flew his downwind leg in trail behind the 150, although the 210, a faster airplane, naturally would call for a wider pattern. He began his descent from the downwind on passing the threshold, although the 150 ahead of him had shown no sign of turning base. And, on seeing that he had overshot the centerline, he tried to hurry back to it. There was no need to hurry; because he was now more than a mile from the runway, he could have taken his time.

Low-time pilots make small errors like this every day. They are rarely fatal. But this time, the accumulation of innocuous elements turned into a massive failure of energy management. The pilot lost awareness of speed and altitude—and that error can easily be fatal.

Editor’s Note: This article is based on the NTSB reports of these accidents and is intended to bring the issues raised to our readers’ attention.