VAN NUYS, CA, USA
N186BA
Cessna 402A
The airplane collided with two school buses during a forced landing on a city street. During a straight-in approach for landing, the pilot lost all power on his left engine. After switching to the left auxiliary tank the engine did not restart. About a minute later all power was lost on the right engine. No attempt was made to switch to the right auxiliary tank because the pilot felt the airplane was too low and he concentrated on making a forced landing on a city street directly in front of the airplane. After touchdown, the airplane's wing tip main fuel tanks collided with the front ends of two approaching school buses. The two main fuel tanks were ruptured in the accident and found empty. Only residual fuel was found in the lines, with 1 quart of fuel recovered from the left auxiliary tank and 4 gallons from the right auxiliary tank. Investigators could not determine the exact fuel load onboard before the first departure that morning; however, based on refueling records, the airplane would have had no less than 122 gallons. During the first leg of flight, a high cylinder head temperature reading led the pilot to make a precautionary landing at an airport just over halfway to the original destination; the total elapsed time at this landing was 1.3 hours. The pilot was then told to reposition the aircraft back to the point of departure. He said he relied on a preplanned flight plan provided by company dispatchers, and he did not recompute the fuel required for the return. No fuel was added before the return flight. The elapsed time on the return flight was 1.2 hours for a total of 2.5 hours. The pilot said that for both legs of the flight he set a fuel flow of 18 gallons per hour per engine (which is above the red line gage limit); the performance charts show that the proper fuel flow setting was 13.35 gallons per hour per engine. Even at the high fuel flow of 18 gph, investigators computed that the airplane should have had a minimum of 12 gallons at the time of the accident, and this fuel remains unaccounted for. The pilot said that at some point during the two legs he switched to his auxiliary tanks until the gauges read 2 and 5 gallons, and then switched back to his main tanks. He could not specifically recall how long he had been flying on the mains when he switched tanks, or on which leg the switch occurred. To avoid unwanted venting of fuel overboard, a specific fuel tank use sequence must be used. The engine driven fuel pumps supply 50 percent more fuel than is required to the metering valves for each engine, with the excess fuel returned to the corresponding main tank. The auxiliary tanks should not be selected until the main tanks have been used for at least 60 minutes so that the mains have room for the returned excess flow from the auxiliary tanks. No evidence of leakage or staining was found around the wing filler caps. Staining found on the pavement around both buses could not be differentiated between fuel and a fire suppressive agent. After the accident, both engines were started and test run with no anomalies noted.
HISTORY OF FLIGHT On June 23, 1999, at 1446 hours Pacific daylight time, a Cessna 402A, N186BA, collided with two school buses while making a forced landing near the Van Nuys, California, airport. The forced landing was precipitated by a total loss of power in both engines while on a VFR approach for landing at the airport. The aircraft sustained substantial damage; however, the certificated commercial pilot, the sole occupant onboard, was not injured. A bus driver and 12 students received minor injuries. There were no injuries to the remaining second bus driver or 36 students. Sunshine Air, Inc., was operating the aircraft as a positioning flight under 14 CFR Part 91 when the accident occurred. The flight originated from the Laughlin/Bullhead International Airport in Bullhead City, Arizona, about 1328 mountain standard time. Visual meteorological conditions prevailed at the time, and no flight plan was filed. The pilot reported that as he approached the Van Nuys airport, he had initiated his descent from 8,500 feet msl, and had lowered 15 degrees of flaps. At the time, he said the fuel gauges read: left main 7 gallons; right main 15 gallons; left auxiliary 2 gallons, and right auxiliary 5 gallons. He reported his position to Van Nuys tower controller as being over Newhall Pass at 1440:58. He was subsequently cleared for a straight-in visual flight rules (VFR) approach to runway 16R and told to report over the San Fernando reservoir. He was cleared to land at 1442:00, and advised that winds were from 150 degrees at 10 knots. As his descent continued to 3,000 feet msl, his left engine lost all power. He switched the fuel selector from the left main to the left auxiliary tank with auxiliary fuel pump on; however, the engine did not regain power. He then switched back to the left main tank. Next the right engine lost all power about 1 minute after the first occurrence. Now descending through 2,000 feet msl, the pilot did not believe that he had time to attempt to diagnose the problem. At 1446:05, he declared an emergency over the tower frequency, saying that he had "lost an engine" and that "we're going down on the uh street." The pilot planned an approach to Hayvenhurst Avenue and subsequently made an off-airport emergency landing on the city surface street about 2,200 feet northwest of the north perimeter airport fence. After touching down about 600 feet north of the intersection with Parthenia Street at an estimated airspeed of 90 mph, the aircraft rolled south until it approached a traffic signal that had just turned red. At the same time, two school buses were simultaneously approaching each other from east and west on Parthenia Street, with a traffic signal that had just turned green. As the school buses entered the intersection, both wing tips collided with the front of each bus as the airplane passed between them. Both main tanks (tip tanks) separated from the airplane and came to rest within the intersection. The pilot was able to brake the airplane to a stop about 1,500 feet south of the intersection. He reported to the tower controller that he was down at 1446:34, and then secured the cockpit before he deplaned. At 0930, prior to his departure from Van Nuys, the pilot had requested that both his main tanks be topped off, and that 10 gallons be added to each auxiliary tank. He observed the refueling process and visually checked the fuel levels. The Peterson Aviation fueling log showed that a total of 89.5 gallons had been dispensed during the refueling operation. The exact amount of fuel on board at takeoff remains unknown. According to the pilot, he had relied on a preplanned or "canned" flight plan and weight and balance form for the flight, which were, according to him, on file with the dispatcher. When the itinerary changed due to a perceived mechanical discrepancy, the pilot said he did not recompute the requirements for the flight. After his initial departure from Van Nuys, en route to Grand Canyon, Arizona, the pilot noted a high cylinder head temperature reading (above red line) for his left engine. At the time there was no corresponding rise in left engine oil temperature observed. As a result of the single instrument reading, he made a precautionary landing in Bullhead City about 1215 mountain standard time. He next contacted the dispatcher, who informed him that another aircraft would be dispatched from Van Nuys to take the passengers on to their destination. The airplane owner then instructed the pilot to reposition the aircraft back to the Van Nuys airport. The pilot reported that he did not add any fuel during his turn around at the Laughlin/Bullhead airport, which was more than halfway to his original destination. After takeoff, he stated that he had climbed with 29.5 inches of manifold pressure and 2,450 rpm, as he always did. He stated that his cruise power setting had been 27 inches and 2,300 rpm. In his statement, he reported that the flight time from Van Nuys to Bullhead City had been 1.3 hours, with an indicated fuel flow of 18 gph per engine or 36 gph total for both engines. The pilot did not report leaning the mixtures. There are no performance charts published in the Airplane Flight Manual (AFM) for an engine that has not been leaned. According to the AFM performance charts, at the recommended cruise setting of 27 inches of manifold pressure and 2,300 rpm, the total fuel consumption should be 26.7 gph, if the airplane has been leaned properly. The maximum-allowable fuel flow is 31.83 gph at redline on the face of the gauge. His reported flight time from Bullhead City to Van Nuys on the return flight was 1.2 hours. The pilot said that at some point, or points, during the flight he switched his fuel selector to his auxiliary tanks until the gauges read 2 and 5 gallons and then he had switched to his main tanks. He could not say how long he had been flying when he switched to the auxiliary tanks, or on which leg, or legs, this occurred. PERSONAL INFORMATION Sunshine Air had employed the pilot since July 1998 as a 14 CFR Part 135 charter pilot. Previously he had been employed as a flight instructor for Runway 3-7 Flight School, La Verne, California, from May 1996 until July 1998. He attended the Professional Pilot Program at Sierra Academy of Aeronautics in Oakland, California, from March 1995 until February 1996. He obtained his commercial pilot certificate on November 2, 1995, and his flight instructor certificate on May 5, 1996. After being hired by Sunshine Air, he completed Aircraft Ground Training and Emergency Training (ground) on July 10, 1998. According to the training records provided by Sunshine Air, the pilot completed his flight training and passed an Airman Competency/Proficiency Check administered by a check airman at Sunshine Air on July 17, 1998. During the check, the records showed that he satisfactorily performed landings with a simulated power plant failure as well as normal, abnormal, and emergency procedures. This was also his initial qualification in the Cessna 402A. On the following February 15, 1999, the records showed that he satisfactorily completed a similar flight check. His records further showed that he had maintained his currency consistently from July 17, 1998, until the day of the accident. The pilot denied being tired or unrested for this, the first flight of the day, nor did the dispatch log have any record of him flying on any of the 3 days prior to the accident. AIRCRAFT INFORMATION Federal Aviation Administration airworthiness inspectors examined the airplane, engine, and propeller logbooks on June 23rd and 24th, 1999. They stated that the airplane was being maintained under an Approved Aircraft Inspection Program (AAIP). They reported that there were no open discrepancies, and that the records they examined, including applicable airworthiness directives (ADs), indicated that the airplane was being maintained in accordance with Federal Aviation Regulations (FARs) as was required by their operations specifications as a condition of their Part 135 certificate. The pilot operating handbook (POH) states that the total aircraft fuel capacity is 143 gallons, which includes 51 gallons (50 gallons usable) in each main tank and 20.5 gallons in each auxiliary tank. Based on the last refueling, the airplane would have had no less than 122 gallons during its initial departure from Van Nuys. Performance charts show that approximately 12 gallons of fuel is used during taxi, takeoff, and climb to 10,000 feet msl. According to performance charts provided by the airplane manufacturer, at the recommended cruise setting of 27 inches of manifold pressure and 2,300 rpm, the total fuel consumption should be 26.7 gph, if the airplane has been leaned properly. The maximum-allowable fuel flow is 31.83 gph at redline on the face of the gauge. The POH also states that before starting the fuel selectors should be positioned on the right and left main fuel tanks. Before takeoff, the fuel selectors should be rechecked to make sure that they are both on the right and left main fuel tanks, and the auxiliary fuel pumps should be in the LOW position. After takeoff, climb, or low altitude cruise, the auxiliary pumps should be in the "OFF" position unless it is necessary to suppress vapor as evidenced by a "nervous" fuel flow needle. The auxiliary fuel pumps are located in the main fuel tanks and have no effect on fuel located in the auxiliary tanks. The POH cautions that the main tanks must be selected for the first 60 minutes of flight. After 60 minutes of flight the auxiliary tanks may then be used. This is because the engine driven fuel pump supplies 150 percent of the fuel required to the metering valves for each engine. The excess 50 percent is returned to the corresponding main tank. When the fuel selector is on the auxiliary tanks, and if the main tanks have insufficient capacity to accept the returning fuel, the excess fuel is then discharged overboard through the tank vents. The left and right fuel transfer pumps, each located in their respective main tanks, had been entered as inoperative in the airplane maintenance logbook. The transfer pumps move fuel from the main tanks to the to the inboard auxiliary tanks to more favorably balance fuel loads. The transfer pumps were not part of the airplane's required minimum equipment list (MEL). The airplane was not listed on the current copy of OST Form 4507 Air Taxi and Commuter Air Carrier Registration and Amendments Under Part 298 of the Regulation of the Department of Transportation, dated May 24, 1999. It was listed on a previous form dated November 17, 1996. This listing is required in order to be in compliance with the operations specification as required by CFR 14 Part 135. In addition, the listing on the current copy of OST Form is a condition required for obtaining liability insurance irrespective of which Federal Aviation Regulation governed the operation. WRECKAGE AND IMPACT INFORMATION Safety Board investigators arrived at the accident scene about 1630 on the afternoon of the accident. They found the accident airplane parked on the west side of Hayvenhurst Avenue just south of Chase Street. Investigators estimated the elevation in the area to be approximately 800 feet msl. About 2 feet of the left most outboard wing section was missing or crushed inward and aft from the tip. The left aileron remained attached by the inboard hinge. About 2 feet of the right most outboard wing section was torn away. The right aileron was missing. Both tip tanks (main tanks) were detached from the wings. No other damage to the airplane was noted at the location at which the airplane came to rest. After an examination of the fuel system, investigators recovered 1 quart of fuel from the left auxiliary tank and 4 gallons from the right auxiliary tank. The fuel that was recovered from the auxiliary tanks had the coloration and odor consistent with aviation fuel. There was no visible fuel contamination detected. Approximately 1.5 cups of fuel was recovered from the right cross feed line. There was no evidence of leakage or fuel staining found on either wing surface or around the fuel caps. About 1,500 feet north of the airplane, in the intersection with Hayvenhurst Avenue and Parthenia Street, investigators found evidence of staining on the pavement around the two damaged school buses. It could not be determined if the staining was from fuel or from fire retardant the fire department said they applied as a preventative measure. Also, there was no odor of fuel at the scene when investigators arrived 1 hour 45 minutes after the accident. There was no evidence of fire at any location, from touchdown to full stop. Both tanks were found in the intersection. Both had ruptured, and were found to be empty of fuel when examined. There was no evidence of hydraulic deformation on either tank. The right aileron was located on the south of the intersection. On June 24, 1999, the airplane was retrieved by Aircraft Recovery Service personnel, and transported to their storage facility located at Compton, California, for further examination. MEDICAL AND PATHOLOGICAL INFROMATION The pilot was not injured. The two school buses were loaded with a total of 48 children and 2 drivers. According to California Highway Patrol (CHP) officers, 12 students and 1 driver received minor injuries. Los Angeles Fire Department paramedics treated one driver and one child at the scene. The injuries were described as contusions and strains. No one required hospital admission. One driver was treated and released at Northridge Hospital, Northridge, California. TESTS AND RESEARCH On July 20, 1999, all parties to the investigation participated in engine runs involving both engines from the accident airplane. The engines were mounted on the airplane and were started and controlled from the cockpit. Each engine was started individually, then run at idle for about 30 seconds, accelerated in excess of 1,700 rpm for an additional 30 seconds, and finally brought back to idle for about 30 seconds before being shutdown. The runs took place at the Aircraft Recovery Services facility located in Compton. The left and right cylinder head temperature gauges were switched before the run, and the left gauge was found to again read high. ADDITIONAL INFORMATION On November 30, 1999, the airplane wreckage was released to Jerry Prince, owner of Aircraft Recovery Services, Compton, based on a mechanic's lien that he had placed on the airplane. According to a letter from the law officers of R. Ted Haas, representing Sunshine Air, Inc., to the law offices of Matthew Fairshter, representing Sussex Aviation, Inc., the insurance policy on the airplane had lapsed due to a lack of premium payment. The registered owner could not be contacted and the insurance company denied coverage. The emergency transmitter locator (ELT) switch was in the "armed" position at the time of the accident, but did not activate. The ELT was later tested and found to operate properly when the switch was moved to the "on" position.
The pilot's inadequate fuel management that resulted in fuel exhaustion and the subsequent collision with vehicles during a forced landing on a city street.
Source: NTSB Aviation Accident Database
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