rk completed./ Aircraft IT. 5.4 Ns N750A aftionalty aim Awatnion taw 11 Jan 2010 oat Keystone Helicopter Corporation has removed the following Sikorsky Type Certificated (TC) options. 33776-84625-011 - Cabin Door Vent Removal. LH 33776-84625-012 - Cabin Door Vent Removal, RH An actual aircraft weighing has been per