Aircraft Accident/Incident Report

Greenbay, Wisconsin 54313
Monday, July 22, 1991 9:05 CDT

NTSB Narrative Summary Released at Completion of Accident

THE TWIN-ENGINE TURBO PROP AIRPLANE WAS CRUISING AT 8000' MSL, WHEN THE LEFT ENGINE'S OUTBOARD AFT UPPER ACCESSORY CASE COWL DOOR SEPARTED FROM ITS MOUNT. THE COWL DOOR STRUCK THE TOP SURFACE OF THE LEFT WING (OUTBOARD OF THE ENGINE NACELLE) & PENETRATED THE WING'S FUEL CELL. THIS RESULTED IN FUEL SIPHONING & PROMPTED THE PILOT TO PERFORM A PRECAUTIONARY ENGINE SHUTDOWN. THE AIRPLANE WAS LANDED WITHOUT FURTHER INCIDENT. AIRWORTHINESS DIRECTIVE (AD) 91-18-11 (EFFECTIVE 9/3/91) REQUIRED STRUCTURAL MODIFICATION OF THE AFT UPPER COWL ASSEMBLY DOORS TO PREVENT INFLIGHT SEPARATION.

NTSB Probable Cause Narrative

INADEQUATE AIRFRAME DESIGN, WHICH RESULTED IN THE IN-FLIGHT SEPARATION OF THE LEFT ENGINE'S OUTBOARD AFT UPPER COWL DOOR.

Event Information

Type of Event Incident
Event Date 7/22/1991
Event Day of the Week Monday
Time of Event 905
Event Time Zone Central Daylight Time
Event City GREENBAY
Event State WISCONSIN
Event Country --
Zipcode of the event site 54313
Event Date Year 1991
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 0
Degrees magnetic from airport 0
Airport Elevation --
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 850 Central Daylight Time
Direction of event from weather observation facility (degrees) 360
Weather Observation Facility ID GRB
Elevation of weather observation facility 695
Distance of event from weather observation facility (units?) 35
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 8000
Lowest Non-Ceiling Height 700
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 3
Air Temperature at event time (in degrees celsius) -18
Dew Point at event time (in degress fahrenheit) -18
Wind Direction (degrees magnetic) 240
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) 0
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 8
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5004
NTSB Notification Source --
NTSB Notification Date Jul 22 1991 12:00AM
NTSB Notification Time 940
Fiche Number and/or location -used to find docket information 43747
Date of most recent change to record Dec 18 2002 11:28AM
User who most recently changed record NTSB\GIUV
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N770M
NTSB Number CHI91IA223
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Minor
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BEECH
Aircraft Model B200
Aircraft Series Identifier B200
Aircraft Serial Number BB1330
Certified Max Gross Weight 12500
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 8
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Unknown
Date of Last Inspection --
Airframe hours since last inspection 0
Airframe Hours --
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name MARSHALL & ISLEY BANK
Aircraft Owner Street Address 770 N. WATER ST.
Aircraft Owner City MILWAUKEE
Aircraft Owner State WI
Aircraft Owner Country
Aircraft Owner Zipcode 53202
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Business
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code MKE
Departure City MILWAUKEE
Departure State WI
Departure Country
Departure Time 835
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code GRB
Destination City GREENBAY
Destination State WI
Destination Country
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --