What happened
Following takeoff, at approximately 1,000 feet above ground level, the pilot observed that the main landing gear would not retract and noted that the hydraulic pressure gauge indicated zero pressure. The pilot attempted to extend the gear, which resulted in three green lights, and utilized the hydraulic emergency hand pump. During the return to the airport, the pilot moved the emergency hand and pump selector valve to the "brake only" position to facilitate stopping the aircraft, though he reported no pressure when using the pump.
On final approach, the pilot slowed the aircraft to approximately 85 miles per hour. Upon touchdown, the pilot attempted to use the hydraulic emergency hand pump for the brakes, but was unsuccessful. The aircraft was unable to stop and subsequently collided with a ditch located beyond the departure end of the runway. There were no injuries reported.
The investigation
Earlier in the week, maintenance had been performed on the left main landing gear actuator and its associated flexible hoses. The mechanic responsible for this work did not complete retraction tests of the landing gear and did not approve the aircraft for return to service.
Upon recovery of the unspecified aircraft, investigators found that the emergency hand pump selector valve was not in the "brakes only" position. Testing revealed that when the selector is set to "brakes only," hydraulic pressure is produced, but this pressure is directed only to the wheel brake system and nose steering cylinder. Consequently, such pressure will not be indicated on the hydraulic pressure gauge.