Aircraft Accident/Incident Report

Sumter, South Carolina 29150
Monday, May 18, 1998 14:20 EDT

NTSB Narrative Summary Released at Completion of Accident

The flight had been airborne about 30 minutes performing airwork, then while flying at 2,000 feet returning to the airport, the CFI noted that the oil pressure was below the lower end of the green arc. He questioned the owner if that was normal; it was not. The engine then began to run rough and began to lose power. Attempts to correct this were unsuccessful. The CFI attempted to perform a forced landing in a field but while on final approach with the throttle still applied, engine power was momentarily restored. He then overflew the intended field and attempted a landing in a freshly plowed field perpendicular to the plowed rows. After touchdown the nose landing gear collapsed and the engine partially separated from the airframe. Disassembly of the engine revealed no evidence of preimpact failure or malfunction. The oil cooler bypass valve was tested which revealed that it did not meet the minimum extension at the midpoint of the test range. The engine had accumulated about 2,091 hours since manufacture with no record of the bypass valve being replaced.

NTSB Probable Cause Narrative

The partial failure of the oil cooler bypass valve which resulted in the over-temperature and loss of oil pressure.

Event Information

Type of Event Accident
Event Date 5/18/1998
Event Day of the Week Monday
Time of Event 1420
Event Time Zone Eastern Daylight Time
Event City SUMTER
Event State SOUTH CAROLINA
Event Country --
Zipcode of the event site 29150
Event Date Year 1998
Event Date Month 5
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 --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1355 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 245
Weather Observation Facility ID SSC
Elevation of weather observation facility 241
Distance of event from weather observation facility (units?) 12
Time Zone of the weather observation EDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 7
Air Temperature at event time (in degrees celsius) 30
Dew Point at event time (in degress fahrenheit) 14
Wind Direction (degrees magnetic) 60
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 1
Injury Total None 1
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 813
NTSB Notification Source --
NTSB Notification Date May 18 1998 12:00AM
NTSB Notification Time 1532
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Feb 16 2001 11:57AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N9884U
NTSB Number MIA98LA166
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Grumman American
Aircraft Model AA-5A
Aircraft Series Identifier AA-5A
Aircraft Serial Number AA5A0284
Certified Max Gross Weight 2200
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 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Apr 15 1998 12:00AM
Airframe hours since last inspection --
Airframe Hours 2091
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name THOMAS A. BEAN
Aircraft Owner Street Address 1803 HOLLY HILL DR.
Aircraft Owner City WEST COLUMBIA
Aircraft Owner State SC
Aircraft Owner Country
Aircraft Owner Zipcode 29169
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) Instructional
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code SMS
Departure City
Departure State
Departure Country
Departure Time 1350
Departure Time Zone EDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Feb 20 2001 6:29PM
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 --