Cessna 750 N15TZ accident near Mesa, Arizona

Probable cause

The pilot’s improper decision to depart on the accident flight with a known hydraulic leak, resulting in an in-flight hydraulic system failure, and the pilot’s attempt to land during an unstabilized approach, which resulted in a loss of control during the landing roll.

NTSB analysis

The pilot and copilot departed on a repositioning flight in the twin-engine jet with a known hydraulic leak. The leak was identified before the flight, but the origin of the leak was unknown at the time. Shortly after departing, the landing gear would not retract. The pilots troubleshot the problem, attempted to retract the landing gear multiple times, and realized they had lost the hydraulic fluid in the system used for gear retraction. The flight diverted to an alternate airport; during the landing, the left landing gear tire blew out and the wheel and tire wore down to near the axle on one side of the wheel. The airplane came to rest near the runway and the right main landing gear collapsed.

A postaccident examination of the airplane revealed that the nose landing gear centering hydraulic flexible line was frayed and leaked near the upper fitting. This damage resulted in the complete depletion of the hydraulic System A fluid during the crew’s multiple attempts to retract the gear during flight.

The cockpit voice recorder (CVR) was downloaded and revealed that, after the landing gear was confirmed in the down position, the pilot reported that they had all the flaps possible extended since they were limited to 15° (per the airplane flight manual [AFM] “LANDING WITH NO ‘A’ SYSTEM PRESSURE” checklist). A few minutes later the crew discussed the flaps again and referred to the flight manual before setting the flaps to the full down position, contrary to the checklist. For the airplane’s reported weight at the time of the landing, the reference landing speed (Vref) specified by the checklist was between 137 and 138 knots; however, the Vref airspeed was exceeded by 17 knots, resulting in a fast landing to a runway with a downhill gradient that constituted an unstabilized approach. The fast landing and selection of a runway with a downhill gradient, both contrary to the referenced checklist, likely contributed to the blown main tires and the loss of control during the landing roll.

Text from the NTSB. Open the NTSB docket for WPR22LA341 for the full record.