Can helicopters fly continuously (aside from refueling) without over heating? If not how long?

Question

Can helicopters fly continuously (aside from refueling) without over heating? If not how long?

Answer 1

Very good answer from cropguy.

I might add that some helicopters, especially piston engine helicopters, may overheat while hovering for extended periods at high DA (temp and elevation) and high power settings.  Usually the transmission is the culprit. The recovery - as specified in most flight manuals - is to fly away at speed with minimum power, so that means around 60 knots.

The time it would take for that to happen would depend on how clean your oil cooler and engine is, the type of helicopter, the gross weight, power settings, DA conditions, and wind.

Its a very rare set of conditions that could lead to overheating. I had a near overtemp on transmission oil once fighting a fire with a Bell 212 in Nevada, where I was moving water buckets over a very short distance with max power virtually all the time and no airspeed. High altitude and high temperature, plus the oil coolers were dirty from all the smoke.  The recovery was to make an extended high speed flight on the empty leg, no big deal except that it added some hours to the job.

Answer 2

A helicopter is no more prone to overheating than a fixed wing airplane, or your car for that matter.  In normal operating ranges and with fuel they could run indefinitely.  Without other problems changing the fluids in your gearboxes ( engine, transmission, tail rotor gearbox ) would be your main concern,and then any components that might reach their time life,and need to be replaced as time is accumulated would be next.  Intentionally exceeding operating limits for extended periods will definitely result in turbine components overheating and causing major damage.  Majorly expensive repairs would follow..  Well into six figures !!!

Answer 3

Don't think the Pilot could fly it while asleep..

Answer 4

hello. the helicopter engines are cooled well. however the gearbox needs cooling,too and this is usually one by a ram air. that means the gearbox/reduction gear is cooled better whenthe helicopter flies forwards. once it starts to hover, it can reach the temperatures that force it to make a short circuit to cool down the oil of the gearbox. /such as my type requires/. otherwise the oil temperatures are dependant fom the ambient air temperature, meaning that the cooler outside air is, the better cooling of the helicopter oil systems.

all helicopters are limited by the takeoff power, continuous use of which in all known types is limited in the use for several minutes only, due to the cooling and temperatures at the combustion chamber and turbine flow. thus the helicopter /unmanned, air refuelled/ would be able to fly until a major failure of systems or until the scheduled flight hours reached /that is- virtually forever/ once it starts hovering, it can overheat fairly well.

it is something like running your car engine idle, in the hot day would mean overheating -ram air for coolling is absent :)

Answer 5

Sure until something wears out from usage.