Date: 202012
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Snow; 6
Light: Night
Aircraft: Learjet 60
Operator: Corporate
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Landing Gear
Component problem: Malfunctioning
Reporter organization: Corporate
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter FOD; Ground Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem; Flight Crew Diverted; General Flight Cancelled / Delayed
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We were on our final phase of flight into ZZZ. It was IMC conditions with light snow upon arrival. The approach was ILS [Runway] XX. Upon landing; I used normal procedures with minimal braking for possible wet/icy runway and thrust reversers. All flight deck indications were as normal as we exit the runway and taxied to the ramp area for the conclusion of the flight. The next afternoon; we prepared to fly back to ZZZ1. The conditions had improved with clear skies and no precipitation. We began to taxi out to the runway completing all of the pre-flight checks and procedures. After takeoff; I began to execute the normal 'after takeoff checklist' with bringing the gear up. The gear did not retract and remained in the down and locked position. I am unsure if the gear came partly up or did not retract a small percentage at all. We climbed to 13;000 ft. and then 15;000 ft. attempting to resolve the situation. Once all procedures and attempts were exhausted; the decision was made to fly with the gear remaining in the down and locked position and head to ZZZ2. The airport weather was clear with light winds; and 10;000 ft. of runway. ZZZ2 was east of the mountains and clear of any weather. We attempted to burn as much fuel as possible as to not land overweight; flying at 17;000 ft. to also clear the terrain between our current position near ZZZ and ZZZ2. As we initiated our descent checklist and before landing checklist; our nose wheel steering was not illuminated and no indications of thrust reversers were available. Approach control and tower were notified of our situation and the possible need for Crash; Fire; Rescue upon landing.We landed at ZZZ2 without incident; I was able to taxi the plane off the runway using a highspeed taxiway. At that point; I stopped the aircraft and requested a tug to FBO on the field. There were no injuries to anyone on board the aircraft. The conclusion of events from information gathered from professional personnel; we encountered FOD upon landing at ZZZ or came in contact with ice buildup at some point during landing or touchdown. It is also possible that we could have encountered FOD upon takeoff the following day with our planned route to ZZZ1. Either occurrence of these two may have rendered our normal systems to function improperly.




Synopsis: LR60 Captain reported a failure of landing gear to retract and elected to fly gear down to a diversion field.