Learjet 25
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer
Flight Crew Last 90 Days 10; Flight Crew Total 14000; Flight Crew Type 100
Training / Qualification; Troubleshooting; Distraction
Aircraft Equipment Problem Critical
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; Flight Crew Took Evasive Action; General Declared Emergency; General Maintenance Action
Aircraft
After initial level off at FL380; observed a right Engine Fire light indication for several seconds. Warning then ceased. [We] performed fire system test. Left engine checked OK; but right engine would not fire test. All other engine parameters appeared normal; but reduced right engine to idle as a precaution. [We] declared emergency and requested clearance back to departure airport. [We] requested fire equipment. Landed; shut down right engine and exited runway. Airfield Rescue and Fire Fighters performed a visual check of right engine and said it looked normal. [We] taxied to ramp for maintenance. Found broken fire detection loop.
A LR25 right engine fire warning momentarily alerted at cruise but was found to be inoperative after a fire system test so an emergency was declared and the flight returned to the departure airport.