Frontier Airlines Flight 851

The lower right engine cowling separated during the takeoff intitial climb. The pilot-in command (PIC) stated the flight deck crew arrived at the airplane at the required show time. The gate agent informed the flight deck crew that a mechanic was working on the brakes. The PIC and first officer (FO) went down to the airplane, did not see anyone, and the logbook was not on the flight deck. The FO departed the flight deck, completed the walk around inspection, and observed nothing unusual. A short time later the mechanic brought the logbook to the flight deck and explained to the PIC that he had worked on the No.1 brake and placed the temperature sensor on the minimum equipment list. The lower right engine cowling separated on initial climbout at 200 feet resulting in a loss of the yellow hydraulic pressure system. The flight crew leveled the airplane off at 3,000 feet, declared an emergency, the flight was cleared by the air traffic controller for an approach to runway 9 left, and landed without further incident. Examination of the airplane's right engine lower cowling by an FAA inspector after the incident revealed all three latches were in the unlocked position. The latch fitting on the aft position was missing and the bolt that secures it was broken. The two forward fittings were in good condition and showed no signs of stress. " The A319 STANDARD OPERATING PROCEDURES EXTERIOR INSPECTION states in GENERAL, "The exterior inspection ensures that the overall condition of the aircraft and its visible components and equipment are safe for the flight. Complete inspection is normally performed by maintenance personnel or in the absence of maintenance personnel by a flight crewmember before each originating flight. Items marked by asterisks (*) must be performed by a flight crewmember before each flight." Item 7, ENG 2 LH SIDE, and item 19, ENG 2 RH SIDE both have an asterisk next to Fan cowl doors, CLOSED/LATCHED." Review of FRONTIER AIRCRAFT FLIGHT LOG for Aircraft Number 904 revealed the Integrated Drive Generator (IDG) required servicing on April 22, 2007. The mechanic endorsed the FRONTIER AIRCRAFT MAINTENANCE NON-ROUTINE SUPPLEMENT SHEET on April 22, 2007, "Serviced #2 IDG IAW AMM 24-21-00-03-02." The FRONTIER MAINTENANCE LINE CHECK LIST, HEAVY SERVICE, CARD No. HS 2010-1, dated February 26, 2007 states on page 7 item 15.1, "Cowlings: panels, air outlets, security of latches." The mechanic indicated with his initials and social security number that this task had been complied with on April 22, 2007. The mechanic entered his initials and social security number on page 12 item 20.1 stating, "Endorse corrective actions in technical log book and sign against each corrected or carried forward item."

Verbatim NTSB analysis and probable cause from the NTSB dataset