An aircraft that crashed after an apparent mid-air break-up is the subject of an airworthiness directive (AD) requiring 50-hourly inspections of its main spar cap.
About 1.50 pm on Sunday afternoon US west coast time (8.50 am Monday morning AEST) a Cessna 414A Chancellor crashed into a house in the Los Angeles suburb of Yorba Linda, after apparently breaking up in mid-air. The aircraft had recently taken off from Fullerton Municipal Airport in Los Angeles and was climbing through 7800 feet, according to news reports. Four people in the house and the pilot who was the only person on the plane, were killed.
The Orange County Register reported the Cessna was built in 1981 and flown by a 75-year-old private pilot who had bought the aircraft last year. Weather at the time was overcast with rain and westerly winds about 7 knots. Reports speak of one engine striking the house, the second engine landing on a road, and the fuselage coming to rest in the yard of another house. News footage shows part of a wing on a roadway.
The Cessna 400 series of light piston twins, which were made from 1962–1987 was the subject of an unusually stringent AD last year. US Federal Aviation Administration AD 2018-03-03 requires repeated inspections of the left and the right forward lower carry-through spar cap for cracks and replacing the carry-through spar if cracks are found. Inspections were to be carried out within 25 flying hours for some 400 series models, or within 50 hours for others. For low-hours aircraft in the 400-series inspections are required before 15,000 hours.
The AD goes on to impose a stringent service requirement: ‘If no cracks are found, repetitively thereafter inspect at intervals not to exceed 50 hours time-in-service.’
As a state of design airworthiness directive AD 2018-03-03 applies to the 110 or so Cessna 401-425 aircraft on the Australian register. The AD affects 2147 aeroplanes on the US register. The US National Transportation Safety Board is investigating.