Hot start

From RC Helicopter Wiki

A hot start is where the helicopter's engine is started while the throttle is not at idle, often because the pilot has selected the wrong model memory on their transmitter.

A hot start is a very dangerous condition, and the main rotor will immediately try to turn very quickly. For this reason, whenever starting an internal combustion powered helicopter, the main rotor head should be gripped firmly with one hand while the starter motor is applied with the other. Should a hot start occur, the engine should be stopped immediately by either pinching the fuel line to the motor, or placing a finger over the exhaust to prevent the exhaust gases from escaping.

Hot starts are less of a problem for electric helicopters as nearly all brushless motor electronic speed controllers will not initialize until the throttle is reduced to minimum. However, some cheap speed controllers for brushed motors are reported not to have hot start protection, and so extreme care is required when starting such helicopters, as both hands are usually required to plug in the battery.

Turbine helicopters also do not suffer from hot starts as the engine FADEC deals with the startup process and should contain hot start protection logic. They can however suffer from wet starts when fuel is added too quickly, causing burning fuel to be ejected from the exhaust in the form of a intense (but hopefully brief!) flame.

[edit] External links

• Induced wet start on turbine helicopter on YouTube.