An atx citation III had a loud air leak squeal in the cabin right after takeoff. The first officer w...

Attributes
ACN	365165
Time
Date	199704
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : yip
State Reference	MI
Altitude	msl bound lower : 1700 msl bound upper : 1700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : yip
Operator	common carrier : air taxi
Make Model Name	Citation III, VI, VII
Operating Under FAR Part	Part 135
Navigation In Use	Other Other
Flight Phase	climbout : takeoff other other
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time total : 5200
ASRS Report	365165
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical inflight encounter other non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	flight crew : declared emergency none taken : anomaly accepted other
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Had a normal takeoff. Shortly afterwards, heard an air noise coming from cabin area. The first officer went in the back to investigate (annunciator panel clear). When the first officer was in the cabin area, the cabin door opened. The first officer stayed in the back, calmed the passenger. Executed an emergency landing. Upon reflection, I think the air noise was not a major problem, possibly a leaky door seal, or a leak from the overhead duct. The first officer stated that he heard the noise from the door area, and he wanted to verify that the door was latched. He said he moved the handle, and about that time, the door opened. I think the first officer opened the door in-flight! It disappoints me that the first officer even touched the door to begin with. Callback conversation with reporter revealed the following information: the reporter flies a C650, citation III, for an atx based at yip. The first officer did not have much experience in the C650. The reporter believes that the first officer moved the handle in the wrong direction, opening the door. The reporter believes that the door locking pins may have been out of alignment allowing the annunciator light to be off when the door was not fully locked. The first officer locked the door before takeoff and checked the pins but probably did not use a flashlight and probably did not know to move the handle hard past 90 degrees. The door had been modified covering up one of the windows used to check the locking pins. The aircraft is back at the factory now getting repairs to the door and its mechanism. The door opens downward to form a step and dragged on the runway. The reporter never saw a door warning light. He has been criticized for sending first officer back to check the door. The aircraft immediately returned to yip.

Original NASA ASRS Text

Title: AN ATX CITATION III HAD A LOUD AIR LEAK SQUEAL IN THE CABIN RIGHT AFTER TKOF. THE FO WENT BACK TO CHK THE SOURCE OF THE SQUEAL AND PROBABLY OPENED THE DOOR INFLT. EMER SIT, APPARENTLY NOT DECLARED. RETURN LAND. DIVERSION TO ALTERNATE.

Narrative: HAD A NORMAL TKOF. SHORTLY AFTERWARDS, HEARD AN AIR NOISE COMING FROM CABIN AREA. THE FO WENT IN THE BACK TO INVESTIGATE (ANNUNCIATOR PANEL CLR). WHEN THE FO WAS IN THE CABIN AREA, THE CABIN DOOR OPENED. THE FO STAYED IN THE BACK, CALMED THE PAX. EXECUTED AN EMER LNDG. UPON REFLECTION, I THINK THE AIR NOISE WAS NOT A MAJOR PROB, POSSIBLY A LEAKY DOOR SEAL, OR A LEAK FROM THE OVERHEAD DUCT. THE FO STATED THAT HE HEARD THE NOISE FROM THE DOOR AREA, AND HE WANTED TO VERIFY THAT THE DOOR WAS LATCHED. HE SAID HE MOVED THE HANDLE, AND ABOUT THAT TIME, THE DOOR OPENED. I THINK THE FO OPENED THE DOOR INFLT! IT DISAPPOINTS ME THAT THE FO EVEN TOUCHED THE DOOR TO BEGIN WITH. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES A C650, CITATION III, FOR AN ATX BASED AT YIP. THE FO DID NOT HAVE MUCH EXPERIENCE IN THE C650. THE RPTR BELIEVES THAT THE FO MOVED THE HANDLE IN THE WRONG DIRECTION, OPENING THE DOOR. THE RPTR BELIEVES THAT THE DOOR LOCKING PINS MAY HAVE BEEN OUT OF ALIGNMENT ALLOWING THE ANNUNCIATOR LIGHT TO BE OFF WHEN THE DOOR WAS NOT FULLY LOCKED. THE FO LOCKED THE DOOR BEFORE TKOF AND CHKED THE PINS BUT PROBABLY DID NOT USE A FLASHLIGHT AND PROBABLY DID NOT KNOW TO MOVE THE HANDLE HARD PAST 90 DEGS. THE DOOR HAD BEEN MODIFIED COVERING UP ONE OF THE WINDOWS USED TO CHK THE LOCKING PINS. THE ACFT IS BACK AT THE FACTORY NOW GETTING REPAIRS TO THE DOOR AND ITS MECHANISM. THE DOOR OPENS DOWNWARD TO FORM A STEP AND DRAGGED ON THE RWY. THE RPTR NEVER SAW A DOOR WARNING LIGHT. HE HAS BEEN CRITICIZED FOR SENDING FO BACK TO CHK THE DOOR. THE ACFT IMMEDIATELY RETURNED TO YIP.

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.

An atx citation III had a loud air leak squeal in the cabin right after takeoff. The first officer went back to check the source of the squeal and probably opened the door in-flight. Emergency situation, apparently not declared. Return land. Diversion to alternate.