CisseV
CisseV t1_ix8mayl wrote
Reply to When a military helicopter fires thousands of rounds while hovering still, does the operator have to slow the rotor to compensate for weight loss? by Legitimate-BurnerAcc
Helicopters generally operate with a fixed range of rotor RPM, lift generated is changed through pitch (collective) of the rotor blades. Weight does impact performance a lot, especially at hover. at higher weights and altitudes, hover might actually not be sustainable.
taking the Apache as a model, wikipedia gives us a weight of
Empty weight: 11,387 lb (5,165 kg)
Gross weight: 17,650 lb (8,006 kg)
Max takeoff weight: 23,000 lb (10,433 kg)
for gun ammo i've taken M789/M788 which ways around 340 grams per cartridge. x1200, which is maximum ammo capacity gives us 408 kilograms of weight in gun ammunition. which is a not insignificant percentage of the weight.
whilst in a hover, weight loss is generally slow because of fire rate (unless you jettison other external stores or fuel tanks), so collective change will be very slow, but will be needed if you dump all your ammo in one go from the same position in a hover.
CisseV t1_ixa3cj1 wrote
Reply to comment by Wonderful_One5316 in When a military helicopter fires thousands of rounds while hovering still, does the operator have to slow the rotor to compensate for weight loss? by Legitimate-BurnerAcc
More ammo means more weight, thus less range. For the Apache specifically, the internal ammo bay can be fitted with an auxiliary fuel tank. In order to extend range or loiter time.