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Allison

Model 250

A very successful series that encompasses both turboshaft and turboprop engines, nearly 50 models since the mid-60's. The 250 is possibly the world's most common small helicopter engine. Model 250
Engine statistics
Specification 250-C20R 250-C30M 250-C40B
Application MD500, Bell 206 AS 350G Bell 430
T/O Power 450 shp 650 shp 715 shp
T/O SFC 0.61 0.59 0.57
Cruise Power 380 shp 600 shp 613 shp
Cruise SFC
Max pwr. pressure ratio 7.9 8.6 9.2
Length (in) 38.8 43.2 41
Dia (in) 23.2 25.7 25.1
Weight 173 lb 250 lb 280 lb