1 Cobra gunships used in the infiltration scene are not  Marine helicopters, but rather the Army model. The Marine version is  an updated model with twin jet engine propulsion turbines, the Army  model used in the infiltration scene still uses a single jet turbine  to turn the rotors. This can be seen by observing the single exhaust  port instead of the twin exhaust on the marine model. During a Navy  S.E.A.L. incursion marine helicopters would escort the transport  helicopter, not Army Cobras as depicted in the film.