NTSB Factual Report

HISTORY OF FLIGHT

On March 19, 1998, at 1659 hours Pacific standard time, a Cessna 310H, N310RR, and a Cessna 152, N6575L, collided in-flight over Corona, California. Both airplanes were destroyed by the collision sequence and postimpact fires. The pilots of both airplanes and one passenger in the Cessna 310 received fatal injuries. The Cessna 310H was operated by the owner under 14 CFR Part 91 and was on a local personal flight from Rialto, California, to the Chino, California, airport. The Cessna 152 was operated by Armstrong Air LLC under 14 CFR Part 91 as a positioning flight and was returning to the Corona airport, where it was based, after departing Riverside, California. Visual meteorological conditions prevailed at the time and no flight plans were filed for either airplane.

According to information developed during the investigation, the owner of the Cessna 310 was positioning the airplane to Chino in order to demonstrate the airplane to a potential buyer. The passenger, who was a licensed aircraft broker, was along in case the buyer decided to purchase the airplane. The aircraft owner was subsequently identified as occupying the left pilot seat. Review of Federal Aviation Administration (FAA) records for the respective control facilities in the vicinity disclosed no record of contract with the Cessna 310 on the day of the accident.

The pilot of the Cessna 152 was the owner of Armstrong Air, and is also a flight instructor. The pilot had taken the airplane to the Riverside airport earlier that morning to complete some dual instructional flights since the Corona airport runway was scheduled to be closed until 1700 for a flood barrier construction job. According to the last dual student who flew with the pilot, they completed a dual lesson at the Riverside airport and the student deplaned. The pilot then performed a walk around inspection of the Cessna 152 and departed for the Corona airport at 1630. The student stated that the pilot was flying the Cessna 152 from the right seat when the airplane left Riverside.

Interviews with the individual who monitors the Common Traffic Advisory Frequency (CTAF) at Corona revealed that the pilot of the Cessna 152 contacted her for an airport advisory at 1656 (according to the clock in her office). The CTAF operator responded that the runway was closed and the pilot advised that he would "circle" while awaiting the airport's reopening. The operator said the pilot called a few minutes later for an advisory and she again responded that the runway was still closed. The pilot replied that he would continue circling. A few minutes later the airport manager advised the operator that the construction people would be on the runway for 5 to 10 minutes more and she passed this information along to the pilot. He responded to her with "get them (the construction people) out of there." The operator stated that she believed a minute or two passed and another airplane broadcast a message advising of the midair collision. According to the clock in her office, the third airplane broadcast the collision message at 1703.

Recorded radar data in the form of a CDR editor listing was obtained from the FAA's SOCAL Terminal Radar Approach Control facility. In addition, recorded radar data was obtained from the Los Angeles Air Route Traffic Control Center in the form of a National Track Analysis Program listing. The data was obtained for all primary target returns and 1200 secondary beacon returns within a 10-mile radius of the Corona airport during the time frame of the respective airplanes known flight times. The computer program Radar Viewpoint was used to sort and view the data. The tracks of both airplanes were identified and tracked backwards in time from the point of the collision. Mode C altitude data was available within the recorded data for both airplanes secondary beacon returns. The raw recorded data and the flight track plots thus derived are appended to this report.

Review of the radar data and plots disclosed that in the 1 minute 18 seconds prior to the collision, the Cessna 310 was descending from a Mode C reported altitude of 4,000 feet on a southeast bound ground track at a computed average rate of descent of 1,200 feet per minute and ground speed of about 180 knots. The track identified as the Cessna 152, which had been orbiting to the southeast of the Corona airport, turned eastbound at 1656, then westbound at 1658. The Cessna 152 then descended from a Mode C reported altitude of 3,000 feet to 2,700 feet and began a turn to a northwest bound ground track in the 9 seconds before the collision. The radar returns merged at 1659:42 at coordinates north 33 degrees 51 minutes 58 seconds by west 117 degrees 36 minutes 17 seconds. At the time the targets merged, the Mode C reported altitude for the Cessna 310 was 2,600 feet and the Mode C report for the Cessna 152 was 2,700 feet. According to the recorded radar data, in the 1 minute 18 seconds prior to the merging of the targets, the horizontal separation decreased from 6.01 nautical miles to zero as the vertical separation decreased by 1,300 feet.

Based on a manual plot of the radar target positions in time sequence, in the 1 minute prior to the collision, the relative horizontal bearing from the Cessna 310 ground track to the Cessna 152 was between 8 and 10 degrees left of the track. During this same period, the relative horizontal bearing from the Cessna 152 ground track to the Cessna 310 was about 25 degrees right of the track until 20 seconds before the collision when the relative bearing changed to about 40 degrees right as the Cessna 152 track maneuvered left before it began the right turn. Trigonometric calculation of a 1,400 altitude difference over 6.01 nautical miles (36,540 feet) yields a 2 degree 10 minute relative vertical angle between the target positions.

According to local pilots who fly into Corona airport, the collision point is consistent with a typical 45-degree entry to the Corona airport's traffic pattern downwind leg for runway 25.

In written statements and oral interviews, ground witnesses who reportedly saw the airplanes collide noted that the Cessna 310 was flying at an altitude lower than the Cessna 152, and "an increase in engine noise" was heard prior to the collision. The witness accounts were consistent in noting that the right wing tip of the Cessna 310 contacted the underside of the Cessna 152's left wing. They then observed a fireball followed by black smoke. Witnesses described what appeared to be an airplane wing descend from the fireball, along with other unidentifiable wreckage.

PERSONNEL INFORMATION

The pilot of the Cessna 310 held a private pilot certificate with airplane single and multiengine land ratings. He also held a third-class medical certificate, dated May 6, 1997, which had two restrictions. The first restriction stated that the holder "shall have available glasses for near vision," and the second restricted the certificate's validity "for night flying or by color signal control." According to the pilot's medical records, he had estimated his total flight time to be 1,150 hours as of May 6, 1997.

The passenger in the Cessna 310 held a commercial pilot certificate with airplane single engine land, multiengine land, and rotorcraft - helicopter ratings, as well as an instrument airplane rating. He held a second-class medical certificate, dated October 13, 1997, with a restriction stating the holder "must have available glasses for near vision." According to his medical records, the passenger had estimated his total flight time to be in excess of 5,000 hours as of October 13, 1997.

The pilot of the Cessna 152 held an airline transport pilot certificate with airplane ratings for single and multiengine land and instruments. He also held a flight instructor certificate with airplane ratings for single engine, multiengine and instruments. The pilot held a second-class medical certificate, dated January 14, 1998, which had a restriction for the holder to wear corrective lenses for near vision. According to his logbook, he had logged 2,020 total flight hours.

AIRCRAFT INFORMATION

The Cessna 310 had been modified by the installation of Continental IO-520-E engines and 3-bladed McCauley propellers in accordance with Colemill Enterprises, Inc., Supplemental Type Certificate (STC) number SA412-SO. The airframe and engine maintenance records were reviewed, with no noted discrepancies or anomalies. The last inspection recorded in the logbooks was an annual inspection, completed on January 1, 1998. The records indicated that at the time of the annual inspection, the total airframe time was 3,895 hours, with both engines accruing 1,723 total hours and 237 hours since major overhaul. No information was available concerning the condition or transparency of the front windshield.

The Cessna 152 had accumulated a total time in service of 5,825 hours. The maintenance records disclosed that a 100-hour inspection was accomplished on March 15, 1998. The student who had flown in the airplane prior to the accident flight reported that the windshield was generally clean with only a few bug spots when he deplaned.

METEOROLOGICAL INFORMATION

The closest official aviation weather observation station is the Chino, California, airport, which is 6 nautical miles on a magnetic bearing of 322 degrees from the accident site. At 1656 local time, the Chino METAR was reporting a 20,000 foot overcast, 7 statute miles visibility, with winds from 230 degrees at 12 knots, and an altimeter setting of 29.94 inHg.

According to a Safety Board computer program, at the time of the collision, the sun was 15 degrees above the horizon on a 246.5-degree magnetic bearing from the accident site.

AERODROME INFORMATION

The Corona airport was scheduled to be closed from 0700 to 1700 on the day of the accident for flood barrier construction on the runway. The airport manager had filed a Notice to Airmen (NOTAM) Form with the FAA. The FAA posted the NOTAM, and the information was available through the Flight Service Station system.

At an elevation of 533 feet msl, the airport has one hard surfaced runway on a 070 - 250 degrees magnetic orientation. The U.S. Department of Commerce, Southwest U.S. Airport Facility Directory lists the traffic pattern altitude as 1,000 feet agl (1,533 feet msl). The traffic patterns are on the south side of the airport, with left traffic for runway 25 and right traffic for runway 7.

WRECKAGE AND IMPACT INFORMATION

The wreckage from the midair collision was distributed over about an 8-block residential area in the city of Corona. During the on-site documentation, pieces recovered from various locations were tagged with an identification number and the place where they were found. Identification of the components was completed with the assistance of technical representatives from Cessna Aircraft. Following the documentation, the wreckage was recovered and a subsequent two-dimensional reconstruction of the two airplanes was accomplished.

The principal wreckage mass of the Cessna 310, minus about the outboard 45 inches of the right wing, descended into a large multiunit apartment complex at 1575 Border Avenue. The GPS derived coordinates of the ground impact were north 33 degrees 51.858 minutes by west 117 degrees 35.846 minutes. A postimpact fire damaged several units of the complex and thermally destroyed the majority of the wreckage at this location. During the recovery and documentation, steel components were identified from the left tip fuel tank and the empennage areas.

The outboard portion of the right wing, including the tip fuel tank, was fragmented and recovered from various locations between the principal wreckage mass impact points of both aircraft. The recovered pieces of right wing tip were not burned or sooted. The principal items recovered and their locations are: 1) forward section of right tip fuel tank at north 33 degrees 52.070 minutes by west 117 degrees 36.286 minutes; 2) structural elements surrounding the right auxiliary fuel tank at north 33 degrees 52.024 minutes by west 117 degrees 36.271 minutes; and 3) aft section of right tip fuel tank at north 33 degrees 51.981 minutes by west 117 degrees 36.256 minutes.

The principal wreckage mass of the Cessna 152, minus the left wing and the associated lift strut, descended into a single-family residential structure at 1151 Hummingbird Lane. The GPS derived coordinates of the ground impact were north 33 degrees 52.251 minutes by west 117 degrees 36.421 minutes. A postimpact fire damaged the structure and thermally destroyed the majority of the wreckage at this location. During the recovery and documentation, steel components were identified from the right wing and the empennage areas.

The outboard 11-foot section of the left wing, with lift strut attached, was found in the back yard of a residence at 1728 Bluebird Lane, coordinates north 33 degrees 52.186 minutes by west 117 degrees 36.253 minutes. The wing section was not burned or sooted. Of the remaining inboard section of the left wing, only two pieces of trailing edge flap were located at various locations in the debris path between the two main wreckage mass locations. The most inboard 14 inches of left flap was distorted, but unburned. The next outboard 23-inch-long section was burned and crushed aft with a semicircular impression about 24 inches in diameter evident. The left fuel tank and all adjoining structural elements were not found.

MEDICAL AND PATHOLOGICAL INFORMATION

A postmortem examination of the Cessna 310 pilot was conducted by the Riverside County Coroner's Office, with specimens retained for toxicological examination. The toxicological test was negative for alcohol. Propoxyphene was detected in the kidney at 0.027 ug/ml and in the liver at 0.094 ug/ml. Norpropoxyphene was detected in the kidney at 0.277 ug/ml and in the liver at 0.953 ug/ml. According to the Physicians Desk Reference, Propoxyphene is a narcotic painkiller, often referred to by the trade name Darvon. Norpropoxyphene is a metabolite of propoxyphene. Carbon monoxide analysis was not performed due to a lack of suitable specimens.

A postmortem examination of the Cessna 310 passenger was also conducted by the Riverside County Coroner's Office, with specimens retained for toxicological examination. The toxicological test was negative for alcohol. Cimetidine was detected in the kidney and liver; however, the detected levels were not quantified. Carbon monoxide analysis was not performed due to a lack of suitable specimens.

A postmortem examination of the pilot of the Cessna 152 was conducted by the Riverside County Coroner's Office, with specimens retained for toxicological examination. The toxicological test was negative for alcohol and for all screened drug substances. Carbon monoxide analysis was not performed due to a lack of suitable specimens.

TESTS AND RESEARCH

The wreckage was collected from the various locations and removed to the facilities of Aircraft Recovery Services, Compton, California, where a two-dimensional reconstruction of both aircraft was accomplished. Impact marks, scrapes, and color transfers were noted, principally on the unburned sections of the Cessna 152's left wing and the recovered fragments of the outboard right wing of the Cessna 310.

The outboard 11-foot section of the Cessna 152 left wing, with lift strut attached, was not burned or sooted. The lift strut remained secured to the wing spar attach points and was observed to have pulled out of the fuselage, with elements of fuselage structure secured to the lower attach lugs. The inboard leading edge of this section was deformed upward and exhibited an orangish-brownish color transfer, which matched the color scheme of the Cessna 310 tip tank. About 34-inches up from lift struts lower fuselage attach lug, an impression was found which matched the dimensions and pattern of the Cessna 310's tip tank forward spar attach lugs. Of the remaining inboard section of the left wing from the root rib out, only two pieces of trailing edge flap were identified. The most inboard 14-inches of left flap was disto

NTSB Probable Cause

The failure of both pilots to maintain an adequate visual lookout and to see and avoid the other airplane.