What happened
On June 26, 2010, a Lockheed P2V-5, registration N1386C, was involved in a landing roll overrun at Rocky Mountain Metropolitan Airport (BJC) in Broomfield, Colorado. The aircraft, operated by the USDA Forest Service, was returning from a retardant drop when the crew experienced a failure of the main hydraulic system.
After configuring the aircraft for landing using emergency hydraulic pressure and declaring an emergency, the crew landed on runway 29R. The pilot intended to exit the runway via taxiway A13 and use the remaining emergency braking system to stop the aircraft on the dirt before reaching the tanker base ramp. However, during the taxi, the pilot attempted to use the emergency brakes with no response. The aircraft proceeded across taxiway A, through a grassy area, and across the northwest portion of the tanker base ramp. The aircraft then exited the prepared surface, went through the airport perimeter fence, descended an embankment, and came to rest nose down on Network Parkway. The crew was not injured and exited the aircraft through the upper hatches.
The investigation
Post-accident examination of the Lockheed P2V-5 revealed the nose gear was broken aft, with significant damage to the bulkheads and walls in the nosewheel well. The nose dome window was broken, and there was damage to the propeller blades, including one bent blade on the right engine and four broken blades on the left engine. Fire damage was also noted on the outer side of the left engine nacelle.
Investigators found a rupture in the line connecting the main hydraulic system and the retardant tank system. Additionally, the investigation determined that during the emergency gear extension process, the co-pilot left the emergency nose gear extension system selector in the "bypass" position. According to the flight manual, this selector should have been returned to "normal," as the bypass position cuts off emergency hydraulic pressure to the elevator flight control and the emergency brakes.