On May 6, 2019, a Piper PA28 140 (registration N5542U) operated by Lightning Aviation was involved in an aviation accident near Foley, AL. One person was killed. Investigators recorded the probable cause as: A partial loss of engine power due to a stuck exhaust valve and the flight instructor's exceedance of the airplane's critical angle of attack following the loss of power, which resulted in an aerodynamic stall at low altitude. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.
On May 6, 2019, a Piper PA-28-140, N5542U, crashed shortly after takeoff from Foley Municipal Airport, Alabama. The student pilot was killed, and the flight instructor was seriously injured.
Accident Overview and Flight History On May 6, 2019, at 1247 central daylight time, a Piper PA-28-140, N5542U, was destroyed when it impacted terrain shortly after takeoff from Foley Municipal Airport (5R4), Foley, Alabama. The flight was a Title 14 Code of Federal Regulations (CFR) Part 91 instructional flight owned and operated by Lightning Aviation. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. The flight instructor was seriously injured, and the student pilot was fatally injured. A witness, a flight paramedic on another instructional flight, observed the airplane take off from runway 36 after a touch-and-go landing. He heard the flight instructor announce on the radio, “My engine just quit.” The witness saw the airplane pitch up “like a power-on stall” and then “lean to the left to start a spin” about 300–400 feet above ground level. Another flight instructor reported that the airplane seemed to be making an aggressive left turn as if returning to the airport. A flight instructor who had flown the airplane earlier that morning noted that it “didn’t seem to climb very well,” which he attributed to high density altitude. He stated that the accident flight instructor was conducting simulated engine-out emergency procedures in the pattern as touch-and-go landings. A different flight instructor who flew the airplane the day before reported engine roughness during simulated engine-out procedures. On the last simulated engine-out procedure, when he added power at 600 feet above ground level, the engine started shaking. He leaned the mixture, and the engine ran smoothly again. He wrote up a maintenance ticket, and a mechanic cleaned the spark plugs, performed an engine run-up, and signed off the maintenance write-up. The instructor subsequently flew the airplane and noted no issues. ## Personnel Information The flight instructor held a commercial pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane, as well as a flight instructor certificate with a rating for airplane single-engine. Her most recent FAA first-class medical certificate was issued February 14, 2019. Her logbook revealed 977.5 total hours of flight experience, of which 507.2 hours were in the accident airplane make and model. Her most recent flight review was completed February 27, 2019, and she had logged about 340 hours of instruction in the previous 90 days. The student pilot had accumulated about 16 hours of total flight experience in the previous 3 years, all in the accident airplane make and model. He had not yet flown solo, and no flights were logged in the preceding year. ## Aircraft and Maintenance Information The four-seat, low-wing, tricycle gear airplane was manufactured in 1969 and powered by a Lycoming O-320-D3G, 140-horsepower engine driving a metal, two-bladed, fixed-pitch Sensenich propeller. An annual inspection was completed on March 12, 2019, at a tachometer time of 6,891.92 hours. The tachometer at the time of the accident indicated 6,985.78 hours, which was 93.86 hours since the annual inspection and 1,976.42 hours since the engine’s most recent major overhaul. ## Meteorological and Airport Information The 1255 recorded weather observation at Sonny Callahan Airport, Fairhope, Alabama, about 8 miles west of the accident location, included wind from 270° at 3 knots, 10 miles visibility, clear skies, temperature 26°C, dew point 17°C, and an altimeter setting of 30.03 inches of mercury. ## Wreckage and Impact Information Examination of the accident site and wreckage revealed several impression marks on the ground along a 243° heading. The airplane came to rest upright on the edge of airport property. All major airplane components were located at the site. The left wing was separated from the fuselage at the wing root and came to rest inverted 18 feet from the main wreckage. The empennage was crushed and folded inverted along the left side of the passenger cabin. The vertical stabilizer was attached and bent 90° to the right at the attachment points. The rudder remained attached and was bent and impact damaged along its entire length. The outboard 3 feet of the right stabilator was impact crushed, and the left side of the stabilator and trim tab was undamaged. The top of the fuselage aft of the front seats was folded back on top of the aft cabin. The forward end of the fuselage, including the instrument panel, forward cabin door, firewall, and engine, were folded down and under the forward cabin floor. The engine remained attached to the mount. The propeller was separated from the crankshaft propeller flange. The left aileron bellcrank, which remained attached to the aileron and balance cables, was located with the fuselage and had been pulled from its mounting and separated from the wing. Control cable continuity was confirmed from the cockpit to each of the control surfaces except the left aileron, which was continuous to the aileron bellcrank. The left wing, including the attached flap and aileron, was impact fractured and damaged on all surfaces. The fuel tank was breached, and the grass around the wing displayed fuel blighting. The landing gear was fractured off and connected by the brake hose. The right wing, including the attached flap and aileron, was crushed from the wingtip to mid-wing and displaced upward with multiple fractures. The outer 2 feet of the flap was crushed in a negative direction, and the inboard 2 feet of aileron was impact fractured, bent, and crushed. The landing gear remained attached. The fuel filler cap remained installed in the filler opening, and fuel was observed in the fuel tank when the cap was removed. The left cockpit seat was separated from its seat rails and from the fuselage. The lap belt was buckled. The outboard end of the lap belt remained attached to its mounting bracket, which was separated from the fuselage. The right cockpit seat remained attached to its seat rails. The lap belt was unbuckled. The airplane was not equipped with shoulder harnesses. Examination of the airframe revealed no preimpact failures of any flight control surface or flight control system components. ## Engine and Propeller Examination The engine and its accessories were examined. The top spark plugs were removed, and visual examination revealed no anomalies. The rocker box covers were removed, and no anomalies were noted with the valve springs and rocker arms. Manual rotation of the engine’s crankshaft produced compression on all four cylinders. The left and right magnetos were removed, and sparks were observed on all towers when each magneto was rotated by hand. Examination of the cylinders with a lighted borescope revealed a circular impact mark consistent with an exhaust valve strike on the No. 4 piston. The No. 4 cylinder was removed from the crankcase. The rocker arm, valve keepers, and springs were removed. The exhaust valve could not be removed from the valve guide by hand and was removed utilizing a hammer and a drift. The exhaust valve exhibited combustion deposits on the stem close to the rear of the valve face. Carbon build-up was observed in the valve guide. The engine-driven fuel pump was removed from the engine and actuated by hand. Bubbles were observed around the gasket when the pump arm was actuated. Four screws on the periphery of the pump were found to be loose. Examination of the propeller blades revealed that one blade was bent forward about mid-span. The blade exhibited leading edge polishing and spanwise scratches on the forward face. The other blade was bent aft about mid-span with twisting towards low pitch. The outer portion of the blade exhibited leading edge polishing and chordwise scratches. ## Additional Information Valve sticking in Lycoming reciprocating aircraft engines is addressed in Lycoming Service Instruction No. 1425A, dated January 19, 1988, Suggested Maintenance Procedures to Reduce the Possibility of Valve Sticking. The Service Instruction is applicable to all Lycoming direct-drive engines and states in part that investigations have shown that exhaust valve sticking occurs more frequently during hot ambient conditions. The lead salts that accumulate in the lubricating oil from the use of leaded fuels contribute to the deposit build up in the valve guides. This condition is eliminated each time the oil and filter are changed. Depending on the amount of deposits, sticking between the valve stem and guide can restrict the valve movement, which is often identified by an intermittent engine hesitation or miss. The Service Instruction further states that exposing the engine to sudden cool down, as in a rapid descent with the power reduced, or shutting the engine down before it has sufficiently cooled down can also induce valve sticking. Textron Lycoming recommends 50-hour interval oil change and filter replacement for all engines using full-flow filtration system. Review of the accident airplane maintenance logs revealed that the engine had accrued 44.48 hours since the last oil change. Valve sticking in Lycoming reciprocating aircraft engines is further addressed in Lycoming Mandatory Service Bulletin 388C and Lycoming Service Instruction 1485A. Mandatory Service Bulletin 388C, which, according to FAA regulations, is not mandatory for aircraft operated under 14 CFR Part 91, calls for all Lycoming reciprocating aircraft engines to be inspected at 400-hour intervals or earlier if valve sticking is suspected. If the valve and guide do not pass the inspection, then corrective action is to be taken as defined in Service Instruction 1485A. Once the guides are replaced with the newer Hi-Chrome guides, inspection is called for every 1,000 hours, half of the published time between overhauls (TBO), or when valve sticking is suspected, whichever occurs first. Review of the accident airplane maintenance logs revealed that the No. 4 cylinder had accumulated a total of 591.85 hours since replacement with an Engine Component Inc. (ECI) Titan cylinder, part number TIST-04-1CA. ECI does not offer guidance regarding the frequency of inspection of the Hi-Chrome valve guides in order to detect valve sticking. A valve inspection was not performed after the flight instructor reported engine roughness the day before the accident flight. FAA Order 8620.2A, National Policy, Applicability and Enforcement of Manufacturer’s Data states in part that unless any method, technique, or practice prescribed by an OEM in any of its documents is specifically mandated by a regulatory document, such as an Airworthiness Directive (AD), or specific regulatory language such as that in Federal Aviation Regulation Part 43.15(b), those methods, techniques, or practices are not mandatory. ## Medical and Pathological Information The Deputy Chief Medical Examiner of the Alabama Department of Forensic Sciences, Mobile, Alabama, performed an autopsy of the student pilot. The cause of death was determined to be from blunt force injuries. Toxicology testing yielded negative findings for ethanol and tested-for drugs. The FAA’s Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on submitted specimens from the flight instructor. The test results yielded negative findings for ethanol and tested-for drugs.