Narrative:

After a cruise descent was initiated (out of 6000 ft for 5000 ft) the cockpit door blew open. The aircraft (BE55) at the time was under approach control, on a radar vector for afw. The flight was on an IFR flight plan, single pilot, from dwh to fwa, with no passenger. The aircraft at the time was also on the autoplt. As a result of the door opening, the aircraft nosed down violently, causing partial loss of control. The autoplt was disengaged, throttle retarded, and pitch adjusted immediately. Rudder effectiveness was noticeably affected by the door opening and remaining open. As a result of the temporary loss of control, the aircraft descended below the assigned altitude of 5000 ft MSL. At the time of the door becoming open and aircraft control was in question, immediate action was initiated by myself to inform the ATC of my situation, and that I was descending below 5000 ft MSL, with no ATC response. It was only after, that I stabilized the aircraft at 4300 ft MSL, the ATC asked what I wanted and what was my altitude. At this time, ATC was finally made aware of my situation. A landing was made at a nearby airport, the door examined, and the flight was continued to afw. Cause: the latch was improperly secured. The door at the beginning of the flight was properly latched and found to be secure. Though the latch mechanism had failed to 'hook' at the top of the door all of the way. The aircraft had recently been painted and new interior and door seals installed. On examination of the door upon landing, I found the top to be worn and tendency not to shut all of the way (without some effort), because of the new seal.

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Original NASA ASRS Text

Title: PLT OF A BEECH BARON, BE55, LOST CTL OF THE ACFT DURING AN IFR DSCNT WHEN THE CABIN COCKPIT DOOR UNEXPECTEDLY OPENED. THE RPTR LOST 700 FT BELOW ASSIGNED ALT BEFORE REGAINING CTL OF THE ACFT. A DIVERSION TO A NEARBY ARPT WAS MADE TO EXAMINE DOOR AND PROPERLY LATCH IT FOR CONTINUED FLT TO DEST.

Narrative: AFTER A CRUISE DSCNT WAS INITIATED (OUT OF 6000 FT FOR 5000 FT) THE COCKPIT DOOR BLEW OPEN. THE ACFT (BE55) AT THE TIME WAS UNDER APCH CTL, ON A RADAR VECTOR FOR AFW. THE FLT WAS ON AN IFR FLT PLAN, SINGLE PLT, FROM DWH TO FWA, WITH NO PAX. THE ACFT AT THE TIME WAS ALSO ON THE AUTOPLT. AS A RESULT OF THE DOOR OPENING, THE ACFT NOSED DOWN VIOLENTLY, CAUSING PARTIAL LOSS OF CTL. THE AUTOPLT WAS DISENGAGED, THROTTLE RETARDED, AND PITCH ADJUSTED IMMEDIATELY. RUDDER EFFECTIVENESS WAS NOTICEABLY AFFECTED BY THE DOOR OPENING AND REMAINING OPEN. AS A RESULT OF THE TEMPORARY LOSS OF CTL, THE ACFT DSNDED BELOW THE ASSIGNED ALT OF 5000 FT MSL. AT THE TIME OF THE DOOR BECOMING OPEN AND ACFT CTL WAS IN QUESTION, IMMEDIATE ACTION WAS INITIATED BY MYSELF TO INFORM THE ATC OF MY SIT, AND THAT I WAS DSNDING BELOW 5000 FT MSL, WITH NO ATC RESPONSE. IT WAS ONLY AFTER, THAT I STABILIZED THE ACFT AT 4300 FT MSL, THE ATC ASKED WHAT I WANTED AND WHAT WAS MY ALT. AT THIS TIME, ATC WAS FINALLY MADE AWARE OF MY SIT. A LNDG WAS MADE AT A NEARBY ARPT, THE DOOR EXAMINED, AND THE FLT WAS CONTINUED TO AFW. CAUSE: THE LATCH WAS IMPROPERLY SECURED. THE DOOR AT THE BEGINNING OF THE FLT WAS PROPERLY LATCHED AND FOUND TO BE SECURE. THOUGH THE LATCH MECHANISM HAD FAILED TO 'HOOK' AT THE TOP OF THE DOOR ALL OF THE WAY. THE ACFT HAD RECENTLY BEEN PAINTED AND NEW INTERIOR AND DOOR SEALS INSTALLED. ON EXAMINATION OF THE DOOR UPON LNDG, I FOUND THE TOP TO BE WORN AND TENDENCY NOT TO SHUT ALL OF THE WAY (WITHOUT SOME EFFORT), BECAUSE OF THE NEW SEAL.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.