Date: 202011
Local time of day: 1201-1800
Location: ZZZZ.ARTCC, FO
Flight conditions: VMC
Light: Daylight
Aircraft: Learjet 35
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Cruise
Aircraft component: Powerplant Fire Extinguishing
Component problem: Malfunctioning
Reporter organization: Corporate
Reporter function: Captain; Pilot Flying
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: We departed ZZZ part 91 to relocate Aircraft X to ZZZ1. Few minutes after crossing ZZZZZ intersection at FL370 in contact with ZZZ Center; I notice a red fire light blinking on left engine accompanied with both red master working lights. No indication of engine stall; no vibration felt; no lost of power notice.Within 5 seconds I retarded to idle the left throttle; 3 seconds later the 'ENG FIRE PULL' Handle light extinguish making me believe that was only bleed air leak in the sensing loop; but 7 seconds later; the 'T' handle again starting flashing indicating fire.I pulled the thrust lever in cutoff position; I pulled the 'T' handle and once the two arm lights where illuminated; I pressed left one first; seconds later when I realized that the fire light was continued flashing; I pressed the second fire extinguishers light to the same engine.Unfortunately; the 'ENG FIRE PULL' handle was still flashing; taking the decision to turn left to the closest airport.We were flying the [airway] eastbound at 85 nm from ZZZ; only 3 airports where closest before ZZZ; but no rescue services most likely or not enough runway available for our landing configuration (gear down; max flaps 20 deg).Since the checklist says 'land as soon as possible' and bad weather was in front of us; while my copilot was advising ATC I started my left turn while descending; circumnavigating the weather (during my 90 deg turn; I looked behind my left shoulder to see if a white or black smoke trail was left behind; but I couldn't see nothing); and after clear of mountains I continued descending to 5;000 feet where I preferred to maintain a low altitude and close to the shoreline if a ditching was necessary.During our diversion we had time to talk to the Controller where we answered every question he asked.Every question was answered at the moment and once we were established on the localizer about 20 nm out; the fire light extinguish. While on my final descent I asked the tower that the ground equipment if possible; to be waiting on the left side of the runway since I was requesting a visual confirmation if actual fire was still on the left side or not.After landing I stopped the airplane and I requested again a visual confirmation and the answer was 'they are on the way.' At that moment with the right engine running; I asked my copilot to open the upper main door since I never felt or saw fire and to have his visual confirmation from him.My intentions were to taxi the airplane out of the runway if no danger or fire existed.As soon as my First Officer opened the door; he gave me the visual that NO FIRE WAS ON LEFT ENGINE and I talked to the Tower that my intentions was to move the airplane out of there to the ramp. The Tower responded to not move since the fire truck was already in my left side. When I saw to my left; I saw a fireman with his hose in position so; I turned off the right engine shutting down everything and jumping out of the airplane. By the time I was stepping out; the fireman started to spray the left engine and I thought that finally a real fire was there.Few seconds later all the fireman started to spray with soapy water the hole airplane; from the cockpit; fuselage; wings and the two engines from the front side and from behind (right engine was only from behind).As soon as I see all that I started to ask the fireman if they saw actually fire; but no fireman spoke Spanish or English. I tried to speak with 5 of them but was a loss of time.By the time they finish spraying the airplane; people from different departments approached the airplane and as soon as I found one who could speak English I asked him to translate the only question I've been asking.'Did anybody see fire?''Can someone say if actually a fire was on either engine?'And the answer was 'No fire was detected by anyone.'After that; we proceeded to tow the airplane out of the runway.


Second narrative: While following our route of flight from ZZZ to ZZZ1 we leveled at 37;000 feet before entering ZZZ [Center] airspace just before the fix ZZZZZ. As we passed that fix; ZZZ Center switched us to ZZZ2 Center and before first contact was made; we had an indication of fire on the left engine.The Captain proceeded with the memory items procedure. He put the left power to idle and we were waiting for that light to extinguish; it did; but in about 8-10 seconds it started flashing again; giving the indication that fire might still be present. Then the Captain continued with the procedure of cutting out the engine to secure it and pull the T-Handle of the left engine; continued by pressing the ARM button of one of the fire extinguishers.The flashing light indicating the possibility of fire in the left engine continued; so the Captain pressed the second ARM button. In both intents to extinguish the light with the fire extinguishers the flashing light of the T-Handle never shut off. So the PIC decided to call on the requested checklist out of the planes QRH and initiated [expedited] descent. I; as the First Office went through the procedures on tab 5 'Engine Fire Shutdown' section of the QRH. I went through all the checklist out loud and twice to confirm everything requested was performed. Then followed the checklist to the single engine landing procedure on tab 14 abnormal checklist; and went through it twice and out loud.While the descent was performed; I advised ATC and asked for vectors to the closest airport; which in this case the only appropriate airport and closest was ZZZ1. The Controller first indicated to fly to a fix which I could not understand and when I asked about 2 times to spell it or give us vectors; he then instructed to fly to the ZZZ VOR. I immediately set the FMS and GPS to the VOR and ZZZ1 airport. The Captain continued VFR descent and decided to cross the mountains as soon as possible so that we can continue descending and get closer to the ground and shore and make a straight in into ZZZ1.While the descent was being performed the left fire; light continued to flash. The Captain took communications while I was setting the procedures into ZZZ1 on the GPS and FMS. In about 3 miles short of the airport. We noticed the light stopped flashing. The Captain requested the Tower to let the rescue and firefighters know that they were needed in our left side once we landed; they confirmed that they were ready and waiting for us. Once we landed and the airplane came to a complete stop I got out if my seat and opened the left exit door to verify if there was any fire present at the moment; I communicated to the Captain that NO fire was visible from the front of the engine and then he instructed for me to get out. As soon as I got out; he was still in communication with the Tower; he shut the right engine as instructed by the Controller and exited the airplane.Once we stepped away from the airplane the firefighters started spraying the left engine immediately through the front and back of the nacelle; and seconds after; another group of firefighters started spraying the right engine. I personally told the captain that if they were spraying is because probably; they saw fire but when I noticed them spraying the right engine too then we thought it was their protocol to follow.Once they stopped spraying the captain asked if they saw fire to several of the Firefighters but they could not understand what we were asking; it was not until a ground handler or someone that understood English approached the airplane and we asked him to ask them if someone saw fire; they answered that No fire was visible. We then proceeded to tow the aircraft out of the runway.Personally; I believe this could be a glitch on the system of the aircraft. I am not a mechanic so it's hard for me to say what might have caused the aircraft to give that indication of fire on the engine. We treated the indication as a real fire so the airplane couldbe secure and everyone on board too. I don't know if this could be a maintenance issue or if it has happened before. My suggestion is just to continue to give the progressive and preventive maintenance to the aircraft as they are required and for the pilots to continue to communicate with maintenance any issues given big or small as no matter how small it may seem it could lead to other problems in the long run. Definitely the airplanes have their years so the more they are used for the missions they are going to require more and more maintenance.


Synopsis: Learjet 35 flight crew reported engine fire indication in flight; resulting in an inflight shutdown followed by a precautionary landing.