Air carrier mdt type aircraft lost door hatch during takeoff roll and aborted the takeoff.

Attributes
ACN	205776
Time
Date	199203
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : bos
State Reference	MA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 30 flight time total : 5000 flight time type : 2500
ASRS Report	205776
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 3300 flight time type : 200
ASRS Report	205577
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : rejected takeoff
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Aborted takeoff. Lost crew hatch on aircraft that caused us to abort at boston logan. Upon doing a complete first flight (preflight) of the day, we started our taxi. During taxi, we noticed water leaking from around hatch, which is normal for an light transport. The first officer confirmed the hatch was secure by pushing on it and we both looked at the red hatch handle and confirmed it locked. As we started our takeoff roll, all was normal until about 50 KTS. At that point the hatch flew off and there was a loud 'bang.' later we found out it was the hatch hitting the vertical stabilizer. We initiated 'abort' of the takeoff and taxied back to the gate. When the hatch was found, it was intact. The handle was broken in the locked position and could not be moved. The cockpit indications were all normal before the incident. There are no annunciator lights for the hatch. Just the red handle in the locked position. Supplemental information from acn 205577. It was later brought to our attention that a ramp person had been on the aircraft with a broom to clean off snow that morning. He may have moved the top hatch handle. There had only been about 2 inches of snow on the aircraft. The 'rampy' said he slipped at one point and may have caught the handle. The only way to insure the hatch is by visual inspection of the handle which is in a vertical position. The hatch was found and inspected. It was found in the locked position. There are no micro switches to monitor the positions of the locking pins.

Original NASA ASRS Text

Title: ACR MDT TYPE ACFT LOST DOOR HATCH DURING TKOF ROLL AND ABORTED THE TKOF.

Narrative: ABORTED TKOF. LOST CREW HATCH ON ACFT THAT CAUSED US TO ABORT AT BOSTON LOGAN. UPON DOING A COMPLETE FIRST FLT (PREFLT) OF THE DAY, WE STARTED OUR TAXI. DURING TAXI, WE NOTICED WATER LEAKING FROM AROUND HATCH, WHICH IS NORMAL FOR AN LTT. THE FO CONFIRMED THE HATCH WAS SECURE BY PUSHING ON IT AND WE BOTH LOOKED AT THE RED HATCH HANDLE AND CONFIRMED IT LOCKED. AS WE STARTED OUR TKOF ROLL, ALL WAS NORMAL UNTIL ABOUT 50 KTS. AT THAT POINT THE HATCH FLEW OFF AND THERE WAS A LOUD 'BANG.' LATER WE FOUND OUT IT WAS THE HATCH HITTING THE VERTICAL STABILIZER. WE INITIATED 'ABORT' OF THE TKOF AND TAXIED BACK TO THE GATE. WHEN THE HATCH WAS FOUND, IT WAS INTACT. THE HANDLE WAS BROKEN IN THE LOCKED POS AND COULD NOT BE MOVED. THE COCKPIT INDICATIONS WERE ALL NORMAL BEFORE THE INCIDENT. THERE ARE NO ANNUNCIATOR LIGHTS FOR THE HATCH. JUST THE RED HANDLE IN THE LOCKED POS. SUPPLEMENTAL INFO FROM ACN 205577. IT WAS LATER BROUGHT TO OUR ATTN THAT A RAMP PERSON HAD BEEN ON THE ACFT WITH A BROOM TO CLEAN OFF SNOW THAT MORNING. HE MAY HAVE MOVED THE TOP HATCH HANDLE. THERE HAD ONLY BEEN ABOUT 2 INCHES OF SNOW ON THE ACFT. THE 'RAMPY' SAID HE SLIPPED AT ONE POINT AND MAY HAVE CAUGHT THE HANDLE. THE ONLY WAY TO INSURE THE HATCH IS BY VISUAL INSPECTION OF THE HANDLE WHICH IS IN A VERTICAL POS. THE HATCH WAS FOUND AND INSPECTED. IT WAS FOUND IN THE LOCKED POS. THERE ARE NO MICRO SWITCHES TO MONITOR THE POSITIONS OF THE LOCKING PINS.

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.