A lear 55 pilot shut down the left engine and discharged one extinguishing bottle in response to a f...

Narrative:

We were given an initial heading of 280 or so and altitude of 2;000 ft. We leveled off at 2;000 and then were cleared to climb to 10;000 on a northwesterly heading. At approximately 4;000 ft; the left engine fire warning illuminated. Power was reduced on both engines and the left engine all the way to idle as we leveled at 4;000. Airspeed was reduced to around 200 KIAS. After approximately 30 seconds; the fire light did not go out and the engine was shut down per the checklist. The fire light still did not extinguish. After another 15-30 seconds; the left fire extinguishing agent was discharged. The fire light then went out. We declared an emergency and were vectored east for landing back at our departure airport. Just east of the coastline; we were asked if we were ready to land and we replied in the affirmative. ATC gave us a 240 heading and asked if we were visual with the runway. We replied yes and were cleared for a visual approach; then changed to the tower and were immediately cleared to land. An uneventful landing was accomplished and we turned off with 2;000 ft of runway remaining. There was no damage to the aircraft and no injuries to the two pilots or two passengers. The problem was determined to be a bad fire warning loop. It was changed and the fire bottle was recharged. We later flew the plane on the original intended mission without incident.

Original NASA ASRS Text

Title: A Lear 55 pilot shut down the left engine and discharged one extinguishing bottle in response to a fire warning shortly after takeoff. The flight returned to the departure airport where Maintenance determined there was no fire and the warning was the result of a faulty fire detection loop.

Narrative: We were given an initial heading of 280 or so and altitude of 2;000 FT. We leveled off at 2;000 and then were cleared to climb to 10;000 on a northwesterly heading. At approximately 4;000 FT; the left engine fire warning illuminated. Power was reduced on both engines and the left engine all the way to idle as we leveled at 4;000. Airspeed was reduced to around 200 KIAS. After approximately 30 seconds; the fire light did not go out and the engine was shut down per the checklist. The fire light still did not extinguish. After another 15-30 seconds; the left fire extinguishing agent was discharged. The fire light then went out. We declared an emergency and were vectored east for landing back at our departure airport. Just east of the coastline; we were asked if we were ready to land and we replied in the affirmative. ATC gave us a 240 heading and asked if we were visual with the runway. We replied yes and were cleared for a visual approach; then changed to the Tower and were immediately cleared to land. An uneventful landing was accomplished and we turned off with 2;000 FT of runway remaining. There was no damage to the aircraft and no injuries to the two pilots or two passengers. The problem was determined to be a bad fire warning loop. It was changed and the fire bottle was recharged. We later flew the plane on the original intended mission without incident.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1072713
Time
Date	201303
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Learjet 55
Operating Under FAR Part	Part 135
Flight Phase	Initial Climb
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Powerplant Fire/Overheat Warning
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Engineer
Experience	Air Traffic Control Non Radar 53 Air Traffic Control Radar 52 Air Traffic Control Supervisory 10 Flight Crew Last 90 Days 250 Flight Crew Total 28000 Flight Crew Type 5000
Events
Anomaly	Aircraft Equipment Problem Critical

A lear 55 pilot shut down the left engine and discharged one extinguishing bottle in response to a fire warning shortly after takeoff. The flight returned to the departure airport where maintenance determined there was no fire and the warning was the result of a faulty fire detection loop.