Portable Speaker Downs ICON A5, Loose Bolt Investigated in C172 Accident
Two general aviation accidents in the last few years demonstrate the importance of thorough maintainer inspections and pilot pre-flight inspections prior to conducting flights after maintenance or service.
In June 2020, at Sky Harbor Airport in Duluth, MN, an ICON A5 suffered catastrophic powerplant failure after the owner/pilot washed the airplane. The pilot stated he used a small portable speaker to play music while washing the aircraft. About 5 seconds after takeoff, he heard a loud bang. He later realized the speaker was missing and couldn’t remember putting it away before taking off.
The National Transportation Safety Board (NTSB) determined the probable cause of this accident was the pilot’s failure to remove an object from the airplane’s exterior, which impacted the propeller blades when he applied full power, causing them to fracture and damage the airplane.
In May 2022, near Toms River, NJ, a Cessna 172 crashed into trees during a training flight. The instructor was teaching landings and slips to landings when on the third landing, the instructor reported the throttle had full travel, but the engine did not respond to inputs for a go-around.
The instructor thought the aircraft would hit trees near the runway, so he decided to try to land in a grass area. The left wing hit the airport fence, and the airplane came to a rest inverted. The accident started a grass fire, but the airplane did not catch fire. There were no injuries.
The probable cause of the Cessna 172 accident is still under investigation, but in an interview with an Air Safety Inspector (ASI), the instructor pilot, who was also the mechanic of the aircraft, was asked about a bolt found at the bottom of the aircraft cowling and a missing nut. The pilot/mechanic said it is possible that he did not install the cotter pin in the bolt but did not remember for sure. However, the ASI interview notes state if the cotter pin was installed, the nut would not have been missing, and the bolt could not back out of the throttle linkage.
There were no fatalities or serious injuries in either accident, but these accidents highlight the importance of proper inspection of an aircraft following servicing or maintenance.
The General Aviation Joint Steering Committee (GAJSC) is a public-private partnership with the goal of improving general aviation safety. The GAJSC is a data-driven organization, using incident and accident data to determine risk of different types of accidents, and has published Safety Enhancements (SE), or recommendations, related to system component failure – powerplant (SCF-PP).
The SCF-PP working group analyzed 70 general aviation accidents in which powerplant failure was a factor. Of those, 35 accidents involved inadequate and/or improper maintenance operations or maintenance operations simply not being performed.
Two Safety Enhancements focused on improved training and outreach to maintenance professionals.
SE 47 – A&P Education/Training stated, “Though the human factors behind these maintenance-related errors were rarely investigated, the reoccurrence of the problem throughout the dataset warranted an SE that would help improve a mechanic’s understanding of critical maintenance procedures and the consequences of not performing maintenance inspections or procedures or doing the maintenance improperly. The best way to accomplish this throughout the maintenance community is through improved training and ensuring that best practices and protocols are not only followed but easily accessible to the A&P.”
SE 49 – SCF-PP Outreach recommended GA associations, in coordination with the FAA, communicate to GA A&P mechanics the importance of checking critical parts during work that makes these parts accessible, even if parts are not the subject of maintenance.
Since then, the FAA published GA Fact Sheet “Advanced Preflight After Maintenance” after the GAJSC and the NTSB determined that a significant number of general aviation fatalities could be avoided if pilots were to conduct more thorough preflight inspections of aircraft that have just been returned to service.
The GA Fact Sheet encourages pilots to conduct an advanced preflight after maintenance or servicing, including ensuring all inspection panels are secure and fasteners are tight and using your senses to determine if something seems unusual or looks out of place.
Implementing these recommendations could have saved these pilots from the trauma of their accidents.