SA-227 AC Metro III
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
General Maintenance Action
Weather
It was extremely cold; -26 degrees on the ramp. At shutdown we put engine blankets on hoping that on our 4 hour wait these would contain enough heat for subsequent start. We did not have engine heat cords onboard. Heated hangar space was not available at that time. Two turboprop aircraft attempted engine starts unsuccessfully prior to our attempt. Each of those needed to be heated in a heated hangar in order to start. On our start attempt; the engine hung at about 600 degrees EGT and 40 percent. We followed hung start procedure. We next discussed starting techniques with Company Maintenance personnel; but the engine wouldn't start in its cold soaked state. We asked FBO attendants if heated hangar space was available. At that time it wasn't; but would become available in 2 hours. Having watched the other aircraft start after being heated; I was confident that this was not a mechanical problem; rather a case of extreme cold. With enough time to warm the engine; I understood that it would start and function normally. Because of the delay required to warm the engine; Company decided to pick up our passengers in another aircraft dispatched from headquarters. It was also decided by Company to send mechanics to our aircraft as well. The aircraft was then placed in a heated hangar and the flight crew left the airport to rest.During our period away; it is my understanding that our maintenance personnel started the warmed engine having performed no maintenance. They ran the engine and detected no mechanical issues. The aircraft was kept warm until the flight crew returned. We were able to start the engine and operate it normally after it had been warmed. I never considered entering a maintenance entry in the aircraft logbook because I didn't interpret this as a mechanical problem nor did I request maintenance personnel. The engine started and operated completely normally when warmed.I would suggest that when we fly to destinations experiencing such extreme cold temperatures that we arrange for the aircraft to be stored in a heated hangar until we are ready to board the aircraft. At the least; Company should consider coordinating with local FBO so that crew can plug in the installed engine heaters.
SA-227 Captain reported he was unable to start the engines because of the extreme cold ambient conditions on the ramp.