Primary finding
Probable cause
the pilot's lack of familiarity with the performance change of the airplane, and the lack of proper training/transition in the modified airplane. Contributing to the accident was inadequate substantiation process and insufficient review by the FAA; the improper weight and balance of the airplane; and the pilot's lack of total experience in this type of aircraft.
Investigator assessment
Analysis narrative
According to witnesses, the airplane used most of the 3,120 foot long runway with slow acceleration, and failed to establish a positive rate of climb. It then collided with a street light pole less than a mile from the runway. The airplane had been modified about 9.7 flight hours prior to the accident flight with an FAA approved turbonormalized/turbo system and speed brakes. According to the company check pilot, the owner/pilot had received 1.5 hours of ground instruction and 1.3 hours of flight checkout on the modification/changes to the airplane. The turbo modification weighed 32 pounds more than reflected in the stc paperwork, and the cg was 3.61 inches forward of the forward limit as the aircraft was loaded. The tip tank fuel cg was in error by 10.9 inches in the stc paperwork. The airplane was over gross weight by 26 pounds. The fuel boost pump was found in the on position, and could have flooded the engine. The spark plugs indicate an over-rich mixture, which could degrade engine performance. Factors associated with the installation can cause a degraded takeoff performance at sea level.
Source record
Factual narrative
HISTORY OF FLIGHT On May 31, 1994, at 0845 hours Pacific daylight time, a Beech A- 36, N4323W, was destroyed after colliding with the ground after the initial takeoff climb at Fullerton, California. The private pilot and passenger were seriously injured, and subsequently succumbed to their injuries. Visual meteorological conditions prevailed for the departure from Fullerton Municipal Airport. The airplane was cleared for takeoff on runway 06 at 0844 hours. The pilot filed a nonstop instrument flight rules flight plan for the personal cross-country flight to Laredo, Texas. The pilot requested an en route altitude of 23,000 feet. Review of the aircraft wreckage and other records disclosed that the aircraft was extensively modified with several Federal Aviation Administration (FAA) approved Supplemental Type Certificates (STC) from the original factory configuration. The modifications included wing tip fuel tanks, an air conditioning system, wing mounted speed brakes, and a turbonormalizing system. The turbonormalizing system and speed brakes were installed on the aircraft about 3 days (9 flight hours) prior to the accident. Complete details on the modifications are discussed in the airplane information section of this narrative. Witnesses located in the FAA Air Traffic Control Tower (ATCT), the coffee shop, and in the vicinity of the runway observed the airplane's takeoff. The witness reports were consistent in stating that the airplane accelerated very slowly on the runway and failed to establish a positive rate of climb after rotation. ATCT personnel stated that the point of rotation was near intersection number two. At this intersection there is about 880 feet remaining of the 3,120 foot-long runway. They also reported that the airplane barely missed trees located just east of the departure end of the runway. Two pilot witnesses were in the same vehicle driving on a nearby surface street and reported observing the airplane traveling in a easterly direction, north of the railroad tracks, which run diagonally across the extended runway centerline. They reported that the tail of the airplane was lower than the nose, and that it was traveling at a slow speed. Only one of several witnesses reported seeing any type of smoke prior to the crash. A motorist near the accident site reported seeing dark smoke coming from the left side of the engine compartment. He also stated that the airplane just cleared some power lines by about 30 feet with the landing gear down. PERSONNEL INFORMATION The pilot's personal flight records were examined. In addition, the pilot's airman and medical certification files maintained by the FAA at Oklahoma City, Oklahoma, were reviewed. On April 30, 1993, the pilot was first issued a combined third class medical and student pilot certificate. On his application he reported a total flight time of 10 hours. Under the Medical History section of the questionnaire that he completed, the pilot answered "No" to experiencing any of the listed medical conditions, including diabetes. He also reported that he was not currently using any prescription or nonprescription medications. In a letter to the Safety Board dated December 12, 1994, the pilot's wife reported that he had been diagnosed as a borderline diabetic in 1989, and was prescribed the medication Micronase to control the condition. She stated that he had no complications associated with the condition. The pilot's personal physician who diagnosed the condition, did not respond to a request for additional information on the pilot's medical history. In a telephone interview, the FAA deputy regional flight surgeon for the Western Pacific Region stated that the pilot's condition was disqualifying for the issuance of a medical certificate of any class without further evaluation of the applicant's medical condition by the FAA medical certification staff. According to the flight surgeon, the medication Micronase is an FAA approved drug for use by pilots on a case-by-case approval basis. Review of the pilot's flight records established that he began his training on April 30, 1993, in a Piper J-3 airplane. On the same day, the second entry noted a flight in the accident airplane. On September 2, 1993, the pilot was issued a private pilot certificate for single engine land airplanes, and he obtained an airplane instrument rating on April 21, 1994. At the time of the accident the pilot had accrued about 485 total flight hours, with about 458 hours in the accident airplane. The pilot's logbook documents a total of 5.5 hours since the installation of a turbocharger/turbonormalizer conversion. On April 22, 1994, the airplane was taken by the pilot to Pagosa Springs, Colorado, for the installation of a turbonormalizer "Turbo-Flite 520" system, in accordance with STC SA522NM. Also installed were speed brakes, aileron gap seals, and an exhaust gas temperature instrument system for a six-cylinder engine. According to the resident pilot for Turbo-Flite (also known as FliteCraft Turbo, Inc.), he flew about 4.2 hours in test flight. He demonstrated and explained the modifications/changes to the pilot's airplane. According to the check pilot, the amount of time for the checkout was 1.5 hours for ground instruction on the modifications, and 1.3 hours of flight demonstration, for a total of about 5.5 hours on the aircraft since the modifications. The check pilot reported that they climbed to 18,000 feet during the demonstration. The flight was not recorded in the owner pilot's log book. At the time of the accident, the airplane had flown about 9.7 hours since the conversion, with about 5.5 hours and three takeoffs and landings made by the owner/pilot. The resident pilot stated that this particular airplane was not a performer. According to the pilot's wife, he arrived in Pagosa Springs on May 26, 1994, about 2130 hours mountain daylight time (mdt), to pickup the airplane at Turbo-Flite the next day. She reconstructed the next few days events from motel and telephone records. The pilot checked out of the motel at 0728 hours mdt, May 27, 1994. The pilot called his wife from the motel at 0810 hours, and said he was leaving the motel and going to the Pagosa Springs airport to pickup the airplane. The airport is located about 7 miles from the motel. The pilot again called his wife at 1041 hours, this time from the airport, and said he was leaving in the airplane for Las Vegas, Nevada. At 1243 hours Pdt, the pilot called his wife and said that he was at Henderson Skyharbor Airport in Las Vegas, where he spent the night with a pilot/instructor friend. According to the pilot's log book entry on May 29, 1994, he flew from Las Vegas to Fullerton, California, about 235 statute miles, and he logged 2.0 hours for that leg. The pilot's wife stated that he was in California on May 28, 1994, according to expense invoices. AIRCRAFT INFORMATION The airplane was manufactured in 1974 as a normally aspirated Beech A-36. According to records that were recovered, the airplane had accumulated about 3,657 total flight hours at the time of the accident. The last documented annual inspection was conducted on March 14, 1994. The last documented fueling of the aircraft was at Fullerton prior to departure. According to fueling records, 96.8 gallons of 100LL aviation fuel were loaded in the aircraft tanks. The fueling technician stated that the addition of the 96.8 gallons filled all four tanks. The turbonormalizing system modifies the normally aspirated Continental IO-520-BA engine by the installation of an exhaust gas-driven turbocharger system, which uses exhaust gases to drive a compressor. According to the Turbo-Flite operations and maintenance manual, the compressor provides high velocity air to the engine intake manifold. According to technical information supplied by the Turbo-Flite Company, at full throttle the turbonormalizer has the capability of maintaining the maximum continuous manifold pressure of 29.5 inches of mercury to well above 16,000 feet, depending on engine and atmospheric conditions. A review of the Beech Pilot's Operating Handbook (POH), p/n 36- 590002-19C2, and the Turbo-Flite supplied POH supplements revealed that there were differences in the normal procedures section. One of the differences referenced by Turbo-Flite (Item 4), is during the climb phase of flight the auxiliary fuel pump be turned off. According to the Beech POH, the pump provides pressure for starting and emergency operation only. The manual cautions that use of the pump during normal operations can cause excessive fuel flows with an overly rich mixture, and possible flooding of the engine. The cockpit fuel pump switch was found in the "on" position during postcrash wreckage examination (see "Wreckage and Impact" section of this narrative). Item 15 of the before-takeoff checklist in the Beech POH calls for the mixture to be full rich, and to maintain a fuel flow of 25.0 to 32.0 gallons per hour (gph). In the Turbo-Flite supplement, page 2, section 2b, under operating limitations, it states: "The fuel flow gauge supplied with the aircraft may not accurately measure fuel flow after addition of the turbonormalizing system." The factory installed combination fuel flow/manifold gauge is not changed or recalibrated in this modification. On page 4 of the Turbo-Flite Operations and Maintenance Manual, under the heading "Momentary Overshoot of Manifold Pressure," the publication states: "under some circumstances (such as rapid throttle movement especially with cold oil) it is possible that the engine can be overboosted slightly." The same overboost possibility is noted under the "Caution" section of page 1. The components of the Turbo-Flite 520 system were removed and weighed. This excluded the weight for the baffle changes, louvers, air intake box, starter adapter change, and the fuel pump. The weight, on an uncalibrated electronic scale, came to 83.7 pounds, excluding the exhaust system weight. Compared to a like A-36, the overall increase in weight was 61.2 pounds. At the request of the Safety Board, Turbo-Flite weighed all components of the Turbo-Flite 520 system, as was installed on the accident airplane. The calculations of weight increase provided by Turbo-Flite was 67.6 pounds, instead of 35.50 pounds, as listed on their May 24, 1994, weight and balance revision for this aircraft. In March of 1995, Turbo-Flite issued a newsletter, "Flitelines" Volume 1, Number 1. In the newsletter under "Notice to Bonanza Owners," the article noted an error that had been made in all of their weight and balance calculations for the turbonormalizer installation. The previous weight figures were about 32 pounds low for the net weight gain to the airplane. In a 1994 trade magazine advertisement by Turbo-Flite, they stated that over 300- plus systems have been installed since 1987. In 1995, another trade magazine article reported a total of 173 systems had been sold. Attempts were made to determine the weight of the airplane at the time of the accident. Due to postcrash fire damage, not all baggage was recovered for weighing. The pilot's weight was obtained from his flight physical. The passenger's weight was obtained from his driver's license. The baggage that was available was weighed to be about 152 pounds. In addition, an oxygen bottle weighed 8 pounds without the masks, according to the manufacturer. Partially consumed liquid containers and paperwork weighed an additional 10 pounds, as estimated. According to extrapolated Beech Aircraft calculations using the latest Turboflite and Osborne data, at takeoff the airplane was about 25.44 pounds over the allowable gross weight, and 3.61 inches forward of the most forward center of gravity (CG) limit. At that weight and balance of the accident airplane, "The aircraft should have been able to takeoff in 2,336 feet with the speed brakes retracted and 2,518 feet with the speed brakes deployed. This assumes that the airplane was properly configured for takeoff and that all systems, including the Turbo-Flite turbonormalizer and the STC'd air conditioner, were functioning normally." With regards to stability and control, Beech Aircraft stated that: "The lateral controllability and maneuverability of the aircraft should have been adequate if the STC's were properly certified." In summary, according to Beech Aircraft: "The flight characteristics of the aircraft in the increased takeoff weight should have been adequate, unless there were adverse effects on low speed flight characteristics due to tip tank and speed brakes." Additional engineering requests were made to Beech Aircraft on what effect would this additional weight have on the engine mount structure, as well as with regards to gust loads. They stated that they do not have engineering data on the affects of the individual STC items, and voiced concerns about the additional gross weight to the airplane. On May 25, 1995, a party representative to the investigation informed the Safety Board of an additional weight and balance error found with the J.L. Osborne wing tip mounted fuel tanks. The manufacturer of the tip tanks listed the 240 pounds of tip tank fuel at an arm of 78.60 inches. The corrected (arm) CG location is 89.50 inches. The Safety Board contacted the manufacturer of the tanks. They stated that for the Beech A-36 installation, the figures will be corrected through an engineering change to the FAA aircraft certification branch at Long Beach, California. Then, after the engineering change is approved or acknowledged, they will send out notifications to all U.S. registered A-36 owners. The foreign A-36 aircraft notification process has not been resolved as yet. The estimate for the number of A-36 tip tank installations was 1,000 kits/installations. Postaccident examination of the airplane cabin area revealed an oxygen bottle, which appeared to have been secured to the left cabin side panel behind the pilot's seat. Examination of the bottle revealed it to be a portable medical type of aluminum construction, with a service pressure of 2,015 psi and a capacity of 24.09 cubic feet. According to the bottle manufacturer, the duration for two people at 23,000 feet msl would be about 2 hours maximum. However, the type of regulator and mask that was available, either standard face mask or nasal-cannula, is not known, and this could effect the duration of the oxygen supply. Examination of the pilot's log book revealed that previous non-stop flights between Laredo and Fullerton had taken from 6.5 to 7.2 hours. METEOROLOGICAL INFORMATION The Fullerton hourly weather observation at 0852 hours was reporting: measured ceiling 2,500 broken; 3,700 broken; visibility 12 miles; temperature 66 degrees Fahrenheit; dewpoint 52 degrees Fahrenheit; wind calm; and the altimeter 30.01 inches of mercury. AIRPORT INFORMATION The Fullerton Municipal airport is 96 feet above sea level. The asphalt runway 06/24 is 3,120 feet long and 75 feet wide. WRECKAGE AND IMPACT INFORMATION An on-scene postcrash examination of the wreckage was conducted on the day of the accident. The wreckage site was located about 1 mile east of the airport. The initial impact point (IPI) was a fallen street light pole located on the north side of Raymer Road. Wreckage was found scattered over a 60-foot-wide by 270-foot-long path on an magnetic track of about 095 degrees. About 35 feet east of the IPI, the right outboard fuel quantity transmitter was found. About 61 feet east-northeast of the IPI, the right wing flap was found separated from the wing. At 75 feet, the right speed brake cartridge assembly was found attached to a rear spar section. About 90 feet east of the IPI, at the center of Raymer Road, there were located nine slash marks. Examination of the propeller blades revealed chordwise striations, leading edge damage, and aft bending with asphalt impregnation. About 145 feet from the IPI, the left nose gear door was found in the road. About 30 feet further, the outboard section of the right wing was found inverted, with the aileron and the tip fuel tank attached. At 270 feet from the IPI, the vertical stabilizer was found severed from the empennage and laying in the road. Next to the vertical stabilizer was the main wreckage of the airplane, located in a median area between the road and railroad tracks. The airplane had sustained postcrash fire damage to the fuselage, cabin, and wings. Postcrash examination of the cabin area revealed a fire damaged switch in the area of the engine controls similar to the fuel boost pump switch location. The aluminum structure and placard around the switch was consumed by postcrash fire damage. Examination of the switch revealed that the switch keyway for indexing the switch position in the mount structure was at the bottom-down position. Examination of the structure of a like airplane revealed that the mount has an indexing hole for the washer tang located at the bottom-down position, which corresponds to the switch in an off position. The fire damaged switch knob was found positioned to the top-up (switch on) position. MEDICAL AND PATHOLOGICAL INFORMATION The pilot succumbed to his injuries on June 10, 1994, while still in the hospital. Medical records were obtained from the hospital. A review of the records disclosed that the pilot was listed as a diabetic on oral hypoglycemic medication at the time of admission. TESTS AND RESEARCH The speed brake annunciator light, located between the tachometer and the fuel flow and pressure instrument was recovered and sent to the NTSB laboratory in Washington, D.C., for analysis. Magnified visual examination of the bulb filament revealed that the filament was intact and attached to the electrical contacts and support posts. The Dukes electric fuel boost pump was examined internally for pump and pump vane condition. All four carbon vanes were found intact. The initial postcrash examination of the engine revealed some sooting of the spark plugs in cylinders No. 2, 4, 5, and 6. The engine and all of the engine components were shipped to the Continental Motors factory at Mobile, Alabama, where it was examined and installed in a factory test cell. On July 13, 1994, the engine was successfully test run. The engine and the engine components met the specifications of the engine manufacturer and the Turbo-Flight modification. Subsequently, the entire fuel system of the engine was removed and returned to Continental Motors for individual testing and examination. The compatibility of the changes made by Turbo- Flite to the engine was reviewed. The fuel pump met all test parameters of the manufacturer and the changes made by Turbo-Flite. Examination of the fuel system components revealed that changes were made to the fuel system by Turbo-Flite. The Teledyne Continental Motors specifications for the accident engine require size 13A fuel injection nozzles to be used. The STC uses 15B nozzles. The STC requires that the engine driven fuel pump be recalibrated to higher pressure settings, though the fuel pump part number does not change. The new fuel pressures are proprietary by the STC holder and not available to the public. The fuel hoses were examined visually, and with compressed air. No unusual signatures or conditions were noted. SUPPLEMENTAL TYPE CERTIFICATE INFORMATION According to Turbo-Flite, the STC's SE3816SW and SA3817SW were issued in August, 1987, as individual STC's. They were amended in February, 1989, as multiple STC's. They were amended again in September, 1991, to limit them to those aircraft serial numbers listed on the attachment to the airframe STC (SA3817SW). The STC's they are currently using, SE5222NM and SA5223NM, were origionally issued on March 21, 1991, as multiple STC's and have been amended several times as they have made changes to the turbo system. These STC's cover both the Turbo-Flite 520 and 550 systems. INTRODUCTION On the FAA Form 8110-1, STC application supporting data; Item 18, Part 1 (f), the FAA is to verify empty weight and CG of aircraft. (FAR 23.29). PERFORMANCE Item 18, Part 2 (4), "It must be shown that takeoff and climb performance as a good as or better than the unmodified aircraft." (CAR 3.84 and CAR 3.85). COMPATIBILITY EXAMINATION FAA Order 8110.4, Type Certification Process, dated December 15, 1970, page 32-1 (c) states, "A new alteration should be compatible with related previous alterations to this aircraft to assure continued conformity with applicable airworthiness requirements." The Osborne Tip Tank, STC SA4-1629, was installed on the accident airplane. The original tip tank fuel CG was listed as 78.6 inches. This was subsequently determined to be in error, and has been corrected by the J.L. Osborne Co. to 89.5 inches. Notification will be sent to about 1,000 Beech model 36 owners who have tip tank installations. ADDITIONAL INFORMATION Some Beech Bonanza operators with aircraft modified similar to the accident aircraft have reported degraded takeoff performance at low density altitude (sea level) conditions, such as, additional takeoff distance and lesser rate of climb. In discussing the takeoff performance with an FAA Aircraft Certification Engineer, it was inferred a degradation may occur due to an induction air heat rise from the compressive effect of the turbocharger of a non-temperature compensated turbonormalizing system in some circumstances. Although the induction air emitting from the turbocharger is passed through a precooler, thermal recovery is not 100 percent. Other factors, such as the aircraft gross weight increase due to the use of certain extended range fuel systems, pilot mixture control adjustment, misuse of fuel boost pump, local atmospheric conditions and pilot technique, also may have a cumulative effect on the takeoff performance. On September 26, 1994, the Safety Board sent a wreckage release (NTSB Form 6120.15), to the registered owner's wife, who declined to accept delivery of the form or sign it. The insurance company representative for the pilot also declined to accept the wreckage. As last seen the wreckage and it's components were located at National Aircraft Salvage, Long Beach, California. The Safety Board did not retain any components of the aircraft. An additional party to the investigation not listed on page 5 is the widow of the pilot, Geraldine F. Dunivant, 205 Century Boulevard, Laredo, Texas 78040. -