El Cajon, CA, USA
N2948H
Ercoupe (Eng & Research Corp.) 415C
After flying for about an hour, the engine lost power and the airplane collided with obstacles and the ground on a freeway during an attempted forced landing. The recently overhauled engine had just been installed the morning of the accident in the airframe and this was the first flight following this maintenance activity. The mechanic who installed the engine said after he completed the reinstallation he performed a 20-minute ground run of the engine. A fuel leak was noted in a fitting in the line to the carburetor and that was tightened. There were no other discrepancies noted in the engine indications. The pilot arrived at the airport after the mechanic had performed the ground run of the engine. He said the mechanic told him that the airplane was ready for a test flight and that he should take it up for about an hour to break-in the engine, changing the rpm setting every 5 minutes. The pilot said he did a preflight inspection, which included the determination that he had 6 gallons in each of the wing tanks and 6 gallons in the header tank, for a total of about 18 gallons. After the preflight, he started the engine and taxied down to the runway where he did his normal run-up process, which included two separate magneto checks. After takeoff he flew out about 3 miles and orbited while varying the rpm every 5 minutes. During the entire flight from engine start, the power plant performed perfectly with no abnormal engine indications. At the end of 1 hour, he reported to the control tower that he was ready to land and turned inbound toward the runway. On final approach, the engine just quit without any precipitating roughness or engine spool down. He said it was "like someone just turned off the key." He did not have enough altitude to make the runway and the airplane hit a fence and landed inverted on the highway. Post accident examination of the engine and related systems found numerous discrepancies and abnormal conditions related to the engine overhaul and its reinstallation in the airframe. While many of these discrepancies would have eventually induced a catistrophic engine failure, they were not contributory to the loss of engine power. Three specific conditions were likely related to the engine power loss. The engine driven fuel pump's outlet fitting was found loose and was easily moved, and the nuts attaching the fuel pump to the crankcase were found to be only finger tight. The nuts securing the P-leads for both magnetos were loose, with the nuts 2-turns from finger tight. The scuffing on the pistons indicates that the overhaul shop did not pre-oil the pistons, rings, and cylinders when the engine was put back together; this dry condition allowed a large quantity of oil to migrate past the rings, fouling the plugs with carbon deposits. The fuel system in the aircraft consists of a 6-gallon tank in each wing and a 6-gallon header tank, which is mounted in front of the cockpit. Fuel is supplied to the engine's carburetor via gravity fed line only from the header tank. The engine driven fuel pump moves fuel from the wing tanks to the header tank to replenish that supply as the engine uses it. According to the Teledyne Continental operating manual for the "C" series engines, the typical cruise fuel consumption rate of the C75 engine is between 5 and 6 gallons per hour. At the conclusion of the impact sequence, the aircraft came to rest inverted, with all three fuel tanks breched. A fuel spill was noted under the fuel tank locations in both wings, and based on the size of the fuel stain, investigators estimated at least 10 gallons had leaked. The loose fitting on the fuel pump likely allowed it to suck air and resulted in inefficeincey to the extent that the header tank was depleted of fuel, which in turn resulted in a fuel starvation event. The mechanic was going to leave town immediately after completing this job for a planned multi week vacation trip.
1.1 HISTORY OF FLIGHT On May 11, 2002, at 1242 Pacific daylight time, a Ercoupe (Engineering & Research Corp.) 415C, N2948H, collided with obstacles and the ground on a freeway in El Cajon, California, during an attempted forced landing following a loss of engine power. No automobiles were involved on the ground. The airplane was owned and operated by the pilot under the provisions of 14 CFR Part 91 of the Federal Aviation Regulations. The airplane was destroyed in the collision sequence. The private pilot, the sole occupant, sustained serious injuries. Visual meteorological conditions prevailed at the time and no flight plan had been filed. The local area post maintenance test flight originated at the Gillespie Field airport, El Cajon, at 1140. According to controllers at the Federal Aviation Administration (FAA) Air Traffic Control Tower at Gillespie Field, when the pilot departed he informed them that he would be breaking in a new engine and would be orbiting northeast of the airport. About 1240, the pilot radioed the local controller and declared an emergency, noting that he had a rough-running engine. At the time he stated his position as 5 miles east of the airport. The local controller cleared the pilot to land on runway 27R. Shortly after that, the pilot stated "mayday mayday." The controller stated that he saw the airplane on final approach and it "nose dived" out of his sight. The airplane collided with the eastern most fence bordering the freeway right of way, then the ground in the northbound lanes of highway 67 about 1/2 mile from the approach end of runway 27R. The airplane came to rest inverted on the freeway. A post accident investigation disclosed that the recently overhauled engine had just been installed in the airframe and this was the first flight following this maintenance activity. The mechanic who installed the engine was initially interviewed on site by a responding FAA inspector. During the interview, he provided the airframe and engine maintenance records to investigators. He stated that the Teledyne Continental C-75 engine had been overhauled and he completed the reinstallation that morning. Following installation, he performed a 20-minute ground run of the engine. A fuel leak was noted in a fitting in the line to the carburetor and that was tightened. There were no other discrepancies noted in the engine indications. The pilot then took the airplane for a post maintenance test flight and engine break-in. The mechanic noted that the carburetor was overhauled at the same time as the engine. 1.1 Pilot's Statement The pilot, who is also the owner of the airplane, was interviewed at his residence following release from the hospital. He said that he did not participate in any of the maintenance activities associated with the removal or installation of the engine. The mechanic who installed the engine is the one who does all of the maintenance on the airplane and has a key to the hangar where the airplane is kept. He noted that it was in late November 2001 that he first became aware of a low oil pressure and a high oil temperature condition. This first manifested itself during a video taping flight over the southern San Diego area. The readings were of such concern that he diverted the flight to Brown Field and landed. The mechanic was contacted by telephone and he came out to troubleshoot the problem. Over a week-long period the mechanic attempted to resolve the problem without success. Eventually he determined that it was safe to move the airplane back to Gillispie Field. The pilot stated that the mechanic telephoned an engine overhaul shop, Barkhorn Precision Engines, and the resulting recommendation was for an overhaul, which the pilot agreed to. He denied that he instructed the mechanic to do only a "bottom end overhaul." He could not recall the date of the last fueling on the airplane, however, he acknowledged that it could have been in early December. While he is unsure of the dates, he believes that the engine was removed in the early December time frame for the overhaul. The overhaul seemed to take a long time and they were anxious to have their airplane back, but he did not pressure the mechanic to get the airplane back quickly. He was advised when the engine was delivered on May 6, and then the mechanic telephoned on May 10 and said the airplane would be ready the next day. The pilot arrived at the airport after the mechanic had performed the ground run of the engine. He was not present during any of the final installation or test run processes. The mechanic told him that the airplane was ready for a test flight and that he should take it up for about an hour, changing the rpm setting every 5 minutes. The pilot said he did a preflight inspection, which included sump checking the fuel tanks. As for determination of quantity, the fuel gage in the cockpit read 3/4ths and the sight gage on the header tank was showing about 6 gallons. He explained that the one fuel gage combines the readings for both wing tanks. He interpreted the readings to mean that he had 6 gallons in each of the wing tanks and 6 gallons in the header tank, for a total of about 18 gallons. On the subject of the fuel tanks, he said that he was under the impression that the mechanic removed the header tank during the engine removal process. After the preflight, he started the engine and taxied down to the runway where he did his normal run-up process, which included two separated magneto checks. He was number 5 for takeoff and was on the ground for about 10 minutes until he received his takeoff clearance. After takeoff he flew out about 3 miles and orbited while varying the rpm every 5 minutes. During the entire flight from engine start, the power plant performed perfectly with no abnormal engine indications. At the end of 1 hour, he reported to the Gillispie Field control tower that he was ready to land and turned inbound toward the runway. On final approach, the engine just quit without any precipitating roughness or engine spool down. He said it was "like someone just turned off the key." He did not have enough altitude to make the runway and did not want to take the chance of injuring someone on the ground by landing in a residential area or on the freeway. He selected a Christmas tree farm and set up to land there; however, he was slightly high and decided to "pancake it into the trees." After the airplane hit, it bounced back into the air and hit a fence. He does not remember anything after that. 1.2 PERSONNEL INFORMATION Review of the records maintained by the FAA in the airman and medical records section disclosed that the pilot held a private pilot certificate with category ratings for airplanes single engine land and gliders. The most recent third-class medical certificate was issued on November 2, 2001, and contained the limitation that correcting lenses be worn for near vision. The pilot supplied his most recent personal flight record logbook for review by investigators. The numeral 3 was written on the outside cover. The book encompasses entries from February 1992 to December 2001. (Note that the engine overhaul began in January 2002 and was completed on May 2, and that this was the first flight since December). The estimated total time is 750 hours, with 70 at night. No determination could be made as to the total time in the airplane; however, all flights listed in this book were in the accident airplane. The pattern of activity averages about 5 hours per month over the course of the logbook entries, with the typical flight lasting around 0.5-hours. A Biennial Flight Review endorsement was dated August 8, 2000, and was completed in the accident airplane. 1.3 AIRCRAFT INFORMATION 1.3.1 General Information Review of FAA Aircraft Registry files disclosed that the airframe, an Ercoupe 415C, serial number 3573, was manufactured in 1946. A Continental C75-12 engine, serial number 3796-6-12, was installed in the airframe. The fuel system in the airplane consists of a 6-gallon tank in each wing and a 6-gallon header tank, which is mounted in front of the cockpit. Fuel is supplied to the engine's carburetor via gravity fed line only from the header tank. The engine driven fuel pump moves fuel from the wing tanks to the header tank to replenish that supply as the engine uses it. According to the Teledyne Continental operating manual for the "C" series engines, the typical cruise fuel consumption rate of the C75 engine is between 5 and 6 gallons per hour. Review of the fueling records at the Gillespie Field airport disclosed that the last documented fueling of the airplane occurred on December 7, 2002, with the addition of 10.0 gallons of 100LL aviation gasoline. 1.3.2 Airframe Logbook This record begins with an entry dated January 3, 1972, with a notation that the annual inspection date was taken from "FAA Form 8320-3". A total airframe time was "estimated" at 1,407 hours, with a new recording tachometer reading of zero hours. At the accident site, the recording tachometer displayed 550.11 hours. The most recent annual inspection was entered and dated May 11, 2002, with a recording tachometer time of 549.16. This entry was not signed by the completing mechanic/IA. In a subsequent interview with investigators, the completing mechanic/IA said that he wanted to wait until after the test flight to sign the return to service endorsement. The annual inspection prior to this one was dated May 13, 2001, at a recording tachometer time of 538 hours. 1.3.3 Engine Logbook As with the airframe record, the engine book begins in January 1972 with the same entry, citing FAA Form 8320-3 as the source for the total time. The estimated total time since new is the same as was listed for the airframe, 1,407 hours. A "top" overhaul was listed on October 23, 1998, at a tachometer time of 451.1 hours. Between the "top" overhaul and the overhaul just prior to the accident, the entries document routine oil changes, with no other major work listed. The last entry was dated May 11, 2002, and notes the engine's reinstallation in the airframe by the mechanic who performed the annual inspection. The entry states that Barkhorn Precision Engines overhauled the engine. As with the airframe annual inspection entry, this entry has the name and certificate number of the mechanic; however, it is not signed. 1.3.4 Mechanic and IA Interviews The mechanic was initially interviewed by telephone on the day of the accident and was subsequently interviewed in person during the investigation. During the initial telephone interview, he stated that he is a mechanic at Golden State Flying Club at Gillespie Field, and that he installed the engine in the airplane after it had been overhauled by a local San Diego area engine shop, Barkhorn Precision Engines. He completed the reinstallation that morning. Following installation, he performed a 20-minute ground run of the engine. A fuel leak was noted in a fitting in the line to the carburetor and that was tightened. There were no other discrepancies noted in the engine indications and he completed the logbook entries releasing the airplane for a test flight. The pilot then took the airplane for a post-maintenance test flight and engine break-in. The mechanic noted that the carburetor was overhauled at the same time as the engine, he believed by the firm El Rio Carburetors. The mechanic was interviewed in person at the facilities of Golden State Flying Club. He stated that he has been an aircraft mechanic since 1946, when he first entered an airframe and power plant mechanic training course. He holds an FAA airframe and power plant mechanic certificate and an Inspection Authorization, which was most recently renewed in March 2001. His work experience includes being a civilian contract mechanic for the US Air Force, two major air carriers, and in general aviation. He came to Golden State Flying Club, his current employer, in 1993. He is currently the head mechanic, with two A & P's working for him. In addition to his full time employment with Golden State, he also does maintenance and annual inspections outside of his employment for personal clients. He recalled that the pilot telephoned him toward the end of November 200,1 and said that they had experienced a very low oil pressure/high temperature condition and had landed the airplane at Brown Field. The mechanic then went to Brown Field to attempt to remedy the situation. He worked on the airplane for the next 5 days at Brown Field and could not totally resolve the problem. During this process, he had telephoned the Continental factory for advice and had talked to the overhaul shop owner. Finally he was able to get the airplane to a safe enough condition to fly it back to Gillispie Field. Based on the overhaul shop owner's recommendation, he advised the pilot that an overhaul was needed. He denied that the pilot had instructed him to do a "bottom overhaul" and denied that he gave any such instruction to the overhaul shop owner. He stated that he instructed the overhaul shop owner to "do what it takes to fix the problem." He also denied removing the header tank during the engine removal process. He simply turned off the fuel valve, effectively sealing the tank from draining. The engine was removed and taken to the overhaul shop in late December. He removed all the accessories except for the engine driven fuel pump and placed them on a bench in the pilot's hangar. After awhile he began questioning why the engine was taking so long for the overhaul completion. He had a month-long vacation planned starting on May 11, and wanted to complete the job for the pilot. The engine finally arrived on May 6, and he began the process of installation. This was done at night after completing his day job. He reported he spent 3 to 4 hours each night on the project. He said that the lighting inside the pilot's hangar was satisfactory for the job. The engine installation went without incident and he put 5 quarts of new mineral oil in the sump from his supply at Golden State. The oil was in new manufacturer's plastic containers with unbroken seals. When the engine arrived, all the accessory holes were sealed with coverings made with duct tape. He installed all the accessories except for the engine driven fuel pump, which was already installed when the engine arrived. The engine was test run on the ground for 20 total minutes in two sessions. After the first, he detected a fuel leak at the 90-degree fuel line elbow fitting where it enters the carburetor and tightened it. The second ground run session was satisfactory. He checked the oil after the ground runs and noted an adequate supply in the sump and observed that the oil was a golden color. The pilot had arrived by that time. He told the pilot to fly the airplane for 1hour and vary the rpm. He began watching the pilot do a preflight inspection. The pilot did ask him something to the effect "Is the fuel good?" He replied that it was, remarking that his meaning was that the fuel should not have deteriorated in the 5 months it sat in the tanks. The mechanic did not look in the wing tanks and had no idea what they contained. He observed about a 6-gallon reading on the header tank sight gage. About this time the pilot's wife asked him a question and he turned around to talk to her for about 3 minutes. When he looked back, the pilot was continuing the preflight inspection. He did not observe the pilot look inside the fuel tanks or do a sump check. After the pilot got in, started the engine and taxied away, he left to go back to Golden State. He became aware of the accident just after it happened and immediately got in his truck and drove there, arriving within 5 minutes of the occurrence. He found the airplane upside down on the freeway. He saw some fuel dripping from the wing tanks and noted that it had not reached pavement edge by the time he arrived. While he could not estimate how much fuel leaked out, he said he did not believe it was very much. In response to a question about how he ensures a quality control check on his work, he said that he alwa
fuel starvation due to the mechanic's failure to properly tighten a fuel line fitting on the engine driven fuel pump, which led to a depletion of the fuel in the header tank. The mechanic's self induced pressure to complete the job prior to leaving on vacation was a factor in the accident.
Source: NTSB Aviation Accident Database
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