NTSB Factual Report

On December 11, 2005, about 1500 Pacific standard time, a Boeing B75N1 (Stearman), N65696, collided with a Cessna 172A, N7187T, while both were attempting to land at the Corona Municipal Airport (AJO), Corona, California. The pilot operated the borrowed Stearman under the provisions of 14 CFR Part 91. The airplane sustained substantial damage. The commercial pilot, the sole occupant, was not injured. The pilot/owner operated the Cessna under the provisions of 14 CFR Part 91. The airplane sustained substantial damage. The pilot and passenger were not injured. Visual meteorological conditions prevailed for the local area flights and no flight plans had been filed for either airplane. The Stearman was conducting pattern work, and the Cessna was returning from a local area flight at the time of the accident.

In a written statement to the National Transportation Safety Board, the pilot of the Stearman stated that he was on his third circuit in the pattern at the time of the accident. He also reported that he was seated in the rear seat of the Stearman. About mid-field on the downwind leg the pilot radioed he was on downwind on the Common Traffic Advisory Frequency (CTAF). After that call, he heard a Cessna report "turning final, number 2, at Corona." The Stearman pilot replied with "Corona traffic, Stearman 696 downwind abeam, left traffic 25, Corona." The Stearman pilot observed a Cessna on short final, with another Cessna on a 1/2-mile final approach, but did not see any other traffic on either the downwind or base legs. He began making S-turns in order to clear the area in front of the nose for traffic. He said he did so because Corona has an offset final approach for noise abatement, "which puts [other] aircraft [on the] final approach in front of the biplane's nose." He did not observe any traffic.

The Stearman pilot extended his downwind leg until the second Cessna on final approach passed him. During the turn to the base leg the pilot radioed his intent, and used the turn to look for traffic below him. After returning to a wings level configuration on the base leg, he glanced to the right to ensure the final approach path was clear.

After the other identified traffic passed him on final, he turned onto the final leg a "few seconds later," and radioed that he was turning onto final. He made the turn to final approach per the noise abatement procedures for the airport. He reported that he was slightly above the "ideal glide path," so he placed the airplane into a slip and used the opportunity to check for traffic below him, and did not observe any traffic.

About 150 yards before the runway threshold, he made a radio call on CTAF indicating that he was on short final approach. About 150 feet above ground level, the pilot saw the right wing of another airplane rising toward the left wing of the Stearman. He applied aft pressure on the flight controls and decreased the descent rate, but was unable to avoid the collision. He climbed to 2,000 feet where another airplane in the pattern checked the Stearman for damage. The Stearman pilot then reentered the traffic pattern and made a normal landing.

The pilot said he never heard any radio calls from the Cessna that he collided with. However, he was sure his radio worked because other aircraft on previous circuits in the pattern had acknowledged his radio calls. Also, after the collision he was able to communicate with another airplane that checked his airplane for damage prior to landing.

The pilot also reported that his altitude on the final approach was 1,533 feet mean sea level.

The pilot of the Cessna also submitted a written report to the Safety Board. He reported that he was seated in the right seat during the accident flight. Upon his arrival at the airport, he saw a Cessna 150 ahead of him as he turned onto the downwind leg. There was a lot of radio talk in the background, which included a Stearman that reported entering the pattern. The airplane in front of him extended it's downwind a long distance out, and there were no other aircraft between the other airplane and the end of the runway. The pilot reported turning onto the base leg and continued to space himself behind the other airplane ahead of him. After the airplane ahead of him landed, he lowered the flaps and started his final descent. The pilot reported a lot of radio chatter, but did not hear any aircraft report turning on the base leg. After the other airplane cleared the runway, he approached the threshold, and slowed his airplane. About 20 feet above ground level something struck them from above. He felt that they were going to hit the ground hard, and he pulled back on the flight controls to get the nose up for the impact. The airplane rolled to a stop in the grass next to the runway.

The pilot reported that Corona's CTAF is used by multiple local airports and was very busy at the time of the accident. There was a lot of chatter and squeals from pilots talking on the radio at the same time. Had he heard the Stearman call the base leg turn he would have looked for him, and he felt that had the Stearman pilot heard his radio calls he would have also looked for his airplane. The pilot indicated that the primary cause of the accident was the radio congestion, and recommended that the radio frequencies be separated for the local area airports, so they would not interfere with each other.

WITNESS STATEMENTS

One witness located at the fuel island on the south side of runway 25 reported that the airport is normally busy on weekends, and the day of the accident was no exception. He observed the Cessna (second airplane) below and behind the Stearman. As both airplanes descended on final, the Cessna caught up to the Stearman, but remained below it. As the airplanes were over the dirt/grass area just short of the runway, it appeared that the Stearman's landing gear touched the top of the Cessna's wing.

Another witness, also a pilot, was located at his hangar underneath the pilot lounge. He reported that he was facing north with a clear view of the runway and final approach path. Both airplanes were on a mile final with the Stearman above and in front of the Cessna. As the two airplanes got closer to the runway, the Cessna overtook the Stearman.

Another ground witness, located midfield facing runway 25 observed two airplanes on final approach. From his viewpoint, the Cessna was below the glide path, and the Stearman was above the glide path. He was concerned that the two airplanes were not in visual contact with each other due to the Cessna's position "well below the normal glide path and with its upper wing configuration would not see the biplane that appeared to be slightly in front and above the [Cessna]." The witness also stated that the Stearman would not have been able to see the Cessna that approached from below and behind the Stearman's position.

A flying pilot that was returning to AJO at the time and monitoring the CTAF frequency reported hearing the Stearman make numerous radio transmissions, reporting "on all legs of the pattern." At no time prior to the event did the pilot overhear radio transmissions from the Cessna.

WRECKAGE AND IMPACT INFORMATION

A Federal Aviation Administration (FAA) inspector examined both airplanes at Corona airport. He reported the following damage to each airplane:

The Cessna sustained damage to the aft portion of the top of the right wing. The right flap was bent downward near the fuselage. The root of the flap was bent upward above the wing surface. Damage consistent with an impact from above was evident in the skin forward of where the flap is bent downward.

The lower left wing of the Stearman sustained minor damage. The left main landing gear showed evidence of white paint transfer signatures.

ADDITIONAL INFORMATION

Corona Airport, as displayed in the Los Angeles Sectional Aeronautical Chart, lies in Class G airspace. Visual Flight Rules requirements have been adopted to assist the pilot in meeting the responsibility to see and avoid other aircraft. There are no requirements for using CTAF to operate in or around Class G airspace.

The Federal Aviation Regulations Title 14 CFR Part 91.113 states the following for right-of-way rules:

"(g) Landing...When two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right-of-way..."

Other publications issued by the FAA (Airman Information Manual 4-1-9, Advisory Circular (AC) 90-66A, AC 90-48C, AC 90-42F) state in part that aircraft equipped with an operable radio at non-towered airports should use the radio to maximize safety. AC 90-42F also recommends radio transmissions on the 45-degree entry, downwind, base, and final legs of the approach.

NTSB Probable Cause

failure of both pilots to see and avoid each other during traffic pattern operations at a non-towered airport.