Conceptual Design of a Small Hybrid Unmanned Aircraft System

Table 8

Results in ISA −25°C and ISA +25°C operating conditions.

Pressure altitude	Air or helium temperature	Helium expected gross static lift; kg per kg He	Helium density	Air density	Gross static lift (see (8))
7	−10.609	6.23	0.161	1.17	2.61
10	−10.609	6.23	0.161	1.17	2.61
13	−10.608	6.23	0.161	1.17	2.61
16	−10.605	6.23	0.161	1.17	2.61
19	−10.605	6.23	0.161	1.17	2.61
7	40.253	6.21	0.158	1.15	2.61
10	40.248	6.21	0.158	1.15	2.61
13	40.233	6.21	0.158	1.15	2.61
16	40.230	6.21	0.158	1.15	2.61
19	40.226	6.21	0.158	1.15	2.61