Accident Summary
On September 17, 2024, at about 1730 eastern daylight time, a Cessna 402C, registration N18VV, operated by Cape Air as a Title 14 Code of Federal Regulations Part 135 scheduled passenger flight, was substantially damaged during a landing incident near Boston, Massachusetts. The pilot and two passengers were not injured.
Pilot's Account
According to the pilot, during climb out, both the left and right hydraulic flow lights flickered. Suspecting a loss of hydraulic pressure, the pilot attempted to extend the landing gear before all pressure was lost, but only the left main landing gear green position light illuminated. The hydraulic flow lights then illuminated steadily. The pilot decided to return to the departure airport, notified air traffic control, and requested delaying vectors to perform checklists. Following the "Landing Gear Will Not Extend Hydraulically" checklist, the pilot verified that the landing gear position indicating lights functioned normally with the "press to test" feature, as they had on the ground before takeoff. With the landing gear switch already down, the pilot slowed the airplane to under 130 knots, pulled the "GEAR HYD" circuit breaker, and pulled the emergency landing gear extension handle. There was no change in the position indicator lights nor any indication or noise that the gear had extended.
Landing and Damage
The pilot subsequently landed on the left main landing gear and began lowering the airplane’s nose. During the landing roll, the right wing contacted a runway light, after which a fuel leak began. The airplane came to rest upright on the right side of the runway at an intersection of the runway and taxiway.
Post-Accident Examination
Examination of the hydraulic system by the operator’s maintenance department revealed a fractured solid hydraulic line connected to the hydraulic system filter, with all hydraulic fluid drained from the system. Maintenance personnel then performed the emergency landing gear extension procedure by pulling the emergency extension handle fully out, observing all three landing gear come down and lock. A review of the airplane’s maintenance records could not determine the age of the hydraulic line or whether any maintenance had been performed on it.
Operator Response
Following the accident, the operator issued a Technical Notice to all maintenance personnel emphasizing the importance of general inspection criteria during maintenance on the airplanes.