How is hypothetical max altitude of a helicopter calculated?

Question

How do engineers calculate the hypothetical max altitude of a helicopter if the mass, altitude and length/curvature of blades are known?

There are different definitions for a ceiling (hovering in ground effect, hovering off ground effect, in forward flight). Helicopter Performance (FAA) and Helicopter Theory. — mins, May 13 '15 at 06:14

score 2 · Answer 1 · answered Jun 23 '15 at 07:14

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From the Source:

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enter image description here It shows how to calculate theoretical maximum altitude a Helicopter can achieve

answered Jun 23 '15 at 07:14

Victor Juliet

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This answer really doesn't respond to the question of "how do we calculate the max altitude a helicopter can achieve". Of the four images included here, only the first contains relevant information, and only states the definition of the absolute ceiling, which is "the altitude at which max power equals required power". The referenced book itself also does not present the method to compute the maximum altitude. – costrom Oct 03 '23 at 15:28

score 2 · Answer 2 · answered Aug 09 '19 at 14:23

The helicopter reaches its ceiling if all installed power is used for propelling the helicopter forwards: there is no more extra power available to climb.

The figure from this answer shows the required power as a function of airspeed: it can be seen that there is an optimal true airspeed where required power has a minimum. It is at this airspeed that the helicopter reaches its OGE ceiling.

So it will be necessary to compute the four types of power at speed and height:

Propulsive & induced power, depending on rotor blade length, tip speed, blade chord and twist, solidity ratio.
Profile, depending on blade profile shape.
Parasitic, depending on fuselage shape, rotor mast shape etc.
Tail rotor, which is again propulsive & blade power of the tail rotor.

How is hypothetical max altitude of a helicopter calculated?

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