History of Flight
On September 4, 2017, about 1358 Pacific daylight time, a Boeing A75N1 airplane, registration N75753, was substantially damaged when it impacted a dry river bed near Santa Paula Airport (SZT), Santa Paula, California. The commercial pilot received serious injuries and the passenger minor injuries. The airplane was operated by a private individual as a personal flight under 14 CFR Part 91. Visual meteorological conditions prevailed; no flight plan was filed for the local flight, which was originating at the time.
The pilot, also the owner of the non-profit organization Fly-Hope-Dream, had completed three previous flights that day. The passenger, along with her husband and daughter, had scheduled flights. The husband’s flight departed around 1400 after difficulty with the primer pump; the daughter’s subsequent flight was uneventful.
After securing the passenger, the pilot taxied to runway 22. The takeoff and initial departure were uneventful, but climb performance decreased as the airplane reached about 500 ft mean sea level (250 ft above ground level). The airplane stopped climbing, and the pilot turned left over the downwind leg, noting a partial loss of engine power. He determined the airplane would not reach the runway due to a rapid sink rate and elected an off-airport forced landing. The pilot stabilized the approach and landed in a three-point attitude, but the airplane contacted thick brush, nosed over, and came to rest inverted in a dry riverbed.
Postaccident photographs showed substantial damage to the upper and lower wings.
The pilot could not confirm performing an engine run-up; witnesses did not recall seeing one. One witness reported a left turn about 1/8 nautical mile from the departure end, with pitch attitude increasing until the left wing dropped, then returning to a standard rate turn. As the airplane rolled onto the downwind leg, it descended nose-high; the witness could not hear the engine but saw the propeller spinning. The pilot reported the mixture was full rich during takeoff.
Personnel Information
The 57-year-old pilot held a commercial pilot certificate with single-engine land and instrument ratings, and a second-class medical certificate issued September 29, 2016, with the limitation “must wear corrective lenses.” His total flight time was 814 hours, including 331 hours in the accident make and model.
He founded Fly Dream, Inc. in August 2014, a 501(c)(3) non-profit offering “Dream Flights” to families of children with life-threatening medical conditions or those grieving a child. The organization had received a Letter of Authorization for commercial air tour operations under 14 CFR Part 91.147 on August 31, 2017, authorizing use of the accident airplane.
Aircraft Information
The airplane was manufactured in 1942 and registered to the pilot on November 18, 2010. It was powered by a Continental W670-6A, air-cooled, 220-horsepower radial engine. The engine was rebuilt on April 26, 2016, and had accumulated 31 hours since. An annual airframe inspection was completed on September 2, 2016, at a tachometer time of 985 flight hours.
Meteorological Information
At 1355, the recorded weather at Camarillo Airport, about 10 statute miles away, included wind 200° at 11 knots, visibility 10 statute miles, overcast ceiling at 2,300 ft, temperature 26°C, dew point 19°C, and altimeter 29.92 inHg. An FAA Special Airworthiness Information Bulletin (CE-09-35) indicated conditions conducive to carburetor icing; for the ambient temperature and dew point, the flight was in “Serious icing (glide power)” conditions. The pilot reported not using carburetor heat during the accident flight.
Wreckage and Impact Information
The following day, a witness observed fuel staining in the sand below the fuel tank cap. The airplane was recovered and stored at a salvage facility. A postaccident examination on November 28-29, 2017, was conducted by an airframe and powerplant mechanic under FAA and NTSB supervision.
The airplane was photographed in post-recovery condition with wings and tail removed. Fuel staining was noted on the bottom trailing edge of the upper wing aft of the fuel tank; the fuel sight gage indicated 0 gallons. The engine cowling was removed. Engine mounts were unremarkable; the left magneto top cover was not fully seated (one retaining screw unsecured, the other found on the lower cowl), and the left magneto P lead nut was finger tight. The right magneto P lead was loosened. Continuity of mixture and throttle controls was confirmed. A visual inspection of the induction tube showed no loose matter; couplings were secure.
Forward spark plugs exhibited normal wear except the No. 4 plug, which was oil fouled; No. 4 cylinder, at the engine’s low point, had collected oil. Several forward ignition harness elbows were bent. A thumb compression test revealed normal compression except No. 3 cylinder at 34 psi; air expelled through the exhaust pipe and some through the oil sump.
Fuel system: 2.5 gallons of fuel resembling 100LL were drained; the sight gage erroneously displayed 25 gallons. The fuel valve moved normally; fuel flowed when ON and stopped when OFF. The strainer had no debris. The carburetor butterfly rotated freely; fuel discharged at full rich. Carburetor gaskets and fasteners were in good condition. Flight controls were traced to their surfaces.
An engine test was attempted after adding 10 gallons of 100LL. A fuel leak was found at the primer line of No. 1 cylinder, with fretting and polishing of the adjacent exhaust tube. The engine did not start despite additional primer, fuel injection at the air filter, removal of magneto P leads, and cleaning plugs. No. 2 spark plugs fired; No. 3 rear plug fired, but No. 3 front plug did not spark.
Magnetos and ignition harness were removed. The right magneto distributor blocks had grease deposits; the left magneto switch wire was wired to a ground. Each magneto tested on a bench fired all 7 electrodes continuously up to 1,500 rpm. When the accident harness and distributor blocks were connected to the right magneto, spark was observed at each coil and elbow. During removal, harness wires were found tie-wrapped to metal shielding between cylinders and engine case.
Carburetor examination by a test facility, with FAA oversight, showed no damage. All seals were good; leak check found no leaks; float had no holes; inlet screen was clean; linkages worked correctly.
Ignition system examination by the NTSB Materials Laboratory revealed that one spark plug had an open circuit between terminal and center electrode; others had nominal resistance. Harness continuity and insulation resistance were measured. Elbows of all top spark plugs were bent beyond 90° with buckling and deformation. Two cables showed low resistance from the spark plug end to the elbow (0.8 and 0.0001 ohms). It was unknown if damage occurred before or after the accident. An area of arcing was observed on the right magneto distributor rotor; cause unconfirmed.
Additional Information
Weight and balance: The airplane was refueled with 32 gallons of 100LL at 0735. Using the pilot’s reported fuel consumption of 14 gal/hr, with 32 gallons initially, 7.5 gallons remained at accident flight start; with full capacity of 46 gallons, 21.5 gallons remained. Two weight calculations were performed: with 57 lbs fuel, total weight 2,585 lbs; with 141 lbs fuel, total weight 2,677 lbs, exceeding maximum gross weight of 2,671 lbs. Both configurations were near but did not exceed recommended loading limits per the flight manual.
Fuel performance computations using the pilot’s cruise consumption (14 gph at 70% power) and full-power consumption (21.5 gph) indicated about 24.5 gallons burned in the prior 1.6 hours of flight, leaving 7.5 gallons if started with 32 gallons, or 21.5 gallons if at full capacity.
An industry specialist who provided mechanic services noted that the absence or loss of one spark plug might not be noticeable unless a magneto check is performed; loss of one plug could result in negligible rpm loss. He also noted marginal cam timing slippage could prevent starting or cause sluggish running. Another specialist stated the Continental W670 is inherently anemic; a cylinder misfire would be noticeable, and a hole in the primer line could cause an induction leak leading to an overly lean mixture.
The investigation found that the pilot had not provided instructions on seat belt operation but fastened passengers’ belts himself. The passenger was not prepared with an evacuation plan. The NTSB suggested developing an egress strategy communicated to passengers, providing seat belt instructions, and having passengers demonstrate understanding. The pilot planned to incorporate these strategies.