 Four weeks after the September 11, 2001 attacks, the first of Raisbeck's prototype Hardened Cockpit Security System was installed.Alaska Airlines, American Trans Air and other airlines operating the Boeing 737 immediately ordered and took delivery of the cockpit doors.The doors included rapid decompression, emergency pilot egress and crash-crew cockpit ingress, bulletproof protection, cockpit-to-cabin visual identification and structural integrity.