Aircraft Accident/Incident Report

Orange Beach, Alabama 36561
Monday, July 4, 2011 14:30 CDT

NTSB Narrative Summary Released at Completion of Accident

The airplane had been modified by several Supplemental Type Certificates (STCs) allowing the use of 91 minimum octane alcohol-free fuel, or a combination of 100LL and 91 minimum octane ethanol-free fuel. After takeoff while operating the engine on a mixture of 100LL and 87 octane automotive fuels with 10 percent ethanol additive, the engine experienced abnormal combustion in the No. 3 cylinder, which burned a hole through the cylinder near the lower spark plug hole. The resulting loss of engine power necessitated a forced landing in water. Postaccident examination of the engine revealed no discrepancies with the power train, ignition, lubrication, or air induction systems that would have led to the event. Metallurgical examination of the No. 3 cylinder revealed no manufacturing defects that would have damaged to the cylinder. No placards were noted by either fuel cap; these were required by the installed STCs specifying minimum octane rating of 91 without alcohol; however, on the day of the accident, the airplane underwent a 100-hour inspection by the pilot-in-command who held a mechanic certificate with airframe and powerplant ratings and inspection authorization; he had also performed the modification allowing the airplane to use automotive fuel. Although no fuel samples were retained for testing, the damage to the cylinder was consistent with the usage of unapproved fuel with too low an octane rating.

NTSB Probable Cause Narrative

The operation of the airplane using unapproved fuels, which resulted in abnormal combustion and subsequent damage to the No. 3 cylinder. Contributing to the accident was the inadequate 100-hour inspection because the mechanic failed to note the lack of placards by either fuel filler cap specifying the minimum automotive fuel grade and no alcohol allowed as specified by the installed STC’s.

Event Information

Type of Event Accident
Event Date 7/4/2011
Event Day of the Week Monday
Time of Event 1430
Event Time Zone Central Daylight Time
Event City Orange Beach
Event State ALABAMA
Event Country --
Zipcode of the event site 36561
Event Date Year 2011
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 301708N
Event Location Longitude 0873209W
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 --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1435 Central Daylight Time
Direction of event from weather observation facility (degrees) 272
Weather Observation Facility ID JKA
Elevation of weather observation facility 17
Distance of event from weather observation facility (units?) 7
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 32
Dew Point at event time (in degress fahrenheit) 19
Wind Direction (degrees magnetic) 160
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 8
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 16
Altimeter Setting at event time (in. Hg) 29.97
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 30791
NTSB Notification Source FAA Birmingham FSDO
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Jan 25 2013 11:29AM
User who most recently changed record johb
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N109DP
NTSB Number ERA11LA388
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CESSNA
Aircraft Model 172N
Aircraft Series Identifier --
Aircraft Serial Number 17270607
Certified Max Gross Weight 2300
Aircraft Category Airplane
Aircraft Registration Class --
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 100 Hour
Date of Last Inspection Jul 4 2011 12:00AM
Airframe hours since last inspection 2
Airframe Hours 2927
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type Unknown
Aircraft Owner Name GULF COAST AERIAL ADVERTISING INC
Aircraft Owner Street Address --
Aircraft Owner City GULF SHORES
Aircraft Owner State AL
Aircraft Owner Country USA
Aircraft Owner Zipcode 36542-2613
Operator is an individual? No
Operator Name GULF COAST AERIAL ADVERTISING INC
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City GULF SHORES
Operator State AL
Operator Country USA
Operator Zip code 36542-2613
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
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) Banner Tow
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code 0AL1
Departure City Foley
Departure State AL
Departure Country USA
Departure Time 1400
Departure Time Zone CDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code 0AL1
Destination City Foley
Destination State AL
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 25 2013 11:30AM
User who most recently changed record johb
Since inspection or accident Last Inspection
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --