What's in your blind spot? (LAX06LA56B)

AOPA Air Safety Foundation

What's in your blind spot?

Did you know that most midair collisions occur during the day, in visual meteorological conditions, and within five miles of an airport?

On Dec. 11, 2005, a Boeing Stearman and a Cessna 172 collided while on final approach to Corona Municipal Airport in Corona, Calif. Fortunately, the pilot of the Stearman and the pilot and passenger in the Cessna survived, but both airplanes were substantially damaged.

The details of what happened that day—at least up until the point of impact—are a bit sketchy. The Stearman pilot was doing pattern work and was on his third circuit when, just after calling midfield downwind on the CTAF, he heard a Cessna report, "turning final, number two, at Corona."

The Stearman pilot saw a Cessna on short final and another on a half-mile final but did not see any traffic on the downwind or base legs of the pattern. For noise abatement purposes, Corona has an offset final approach course that put other aircraft on final in front of the biplane's nose; with this in mind, the Stearman pilot performed some S-turns to clear the area. He also extended his downwind leg until the second Cessna on final passed abeam the Stearman.

Meanwhile, a Cessna 172 was also on the downwind leg—possibly below the Stearman. The Cessna 172 pilot had heard the Stearman report midfield downwind and noted a Cessna 150 in the pattern ahead of him. Like the Stearman, the Cessna 172 pilot extended his downwind for spacing and, following the Cessna 150, turned base and final.

About 150 yards from the runway threshold, the Stearman announced that he was on short final, and shortly thereafter caught a glimpse of the Cessna's right wing rising toward his own left wing. He tried to arrest his descent to prevent a collision but was unsuccessful. The Cessna was forced to the ground, while the Stearman pilot was able to reenter the traffic pattern and make a normal landing.

Witnesses saw both airplanes on final approach, with the Stearman above and ahead of the Cessna. The Cessna overtook the Stearman from below and collided with it. Another pilot in the pattern heard the Stearman report all legs of the pattern, but did not hear any radio calls from the Cessna.

The NTSB determined the probable cause of this accident to be the failure of both pilots to see and avoid each other during traffic pattern operations at a nontowered airport.

Both of these pilots are lucky to be alive. Most midair collisions end with fatalities. Many factors contributed to this accident, but the Cessna pilot's apparent failure to make traffic pattern calls was prominent among them. The respective designs of the aircraft involved didn't help matters. With the high wing aircraft flying below the biplane, a large blind spot was created, and neither pilot could see the other airplane. Pilots need to be especially vigilant when scanning for traffic, especially in a busy traffic pattern.

Posted Wednesday, November 14, 2007 12:54:48 PM