Somerset County Airport
Aircraft Accident/Incident Report

Somerset, Pennsylvania 15541
Wednesday, May 10, 2006 15:25 EDT

NTSB Narrative Summary Released at Completion of Accident

The experimental airplane had accrued 27 hours of total flight time, and had just completed its 25-hour Phase I flight testing period. Witnesses related that they saw the airplane engine start, and that the crew appeared to go through an extensive series of checks for approximately 10 minutes prior to takeoff. The engine idled smoothly, and was accelerated several times prior to taxi, once to full power. At takeoff, with a tailwind, the airplane accelerated smoothly, and rotated at a point along the runway that the witnesses thought was later than usual. The airplane pitched nose-up about 20 to 30 degrees in the climb, and the landing gear retracted. When the airplane reached treetop height, black smoke trailed from the engine exhaust system, and the engine "sputtered." The airplane entered a smooth roll to the left, yawed left, and then "plunged" to the ground, in a near vertical attitude. Witnesses said the turn after the loss of engine power was performed at a very high deck angle. Examination of data extracted from the airplane's electronic flight instrumentation system revealed that during the takeoff roll, the fuel flow was more than 20 percent above maximum, and the propeller was over-speeding. The engine rpm, fuel flow, and "Engine" warnings on the multi-function displays should have been visible to the crew. Examination of flight data revealed that the airplane continued to pitch-up as high as 22 degrees, as altitude decreased and airspeed decayed. Examination of the cockpit schematic revealed that the auxiliary fuel pump "high boost/low boost" switch was positioned next to the "Nav" lighting switch. In the airplane's "Before Takeoff" checklist, the "Lights-as required" task was to be performed four tasks prior to the "Takeoff" checklist.

NTSB Probable Cause Narrative

The pilot's failure to maintain sufficient airspeed after takeoff to preclude a stall, which resulted in a loss of control and an inadvertent stall. Factors associated with the accident are the inadvertent stall, the loss of engine power due to the pilot's inadvertent activation of the high pressure auxiliary fuel pump, and the pilot's failure to abort the takeoff after receiving abnormal engine and fuel flow warnings on the primary flight display.

Event Information

Type of Event Accident
Event Date 5/10/2006
Event Day of the Week Wednesday
Time of Event 1525
Event Time Zone Eastern Daylight Time
Event City Somerset
Event State PENNSYLVANIA
Event Country --
Zipcode of the event site 15541
Event Date Year 2006
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 400220N
Event Location Longitude 0790052W
Event Location Airport Somerset County Airport
Event Location Nearest Airport ID 2G9
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 2272
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1454 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 45
Weather Observation Facility ID JST
Elevation of weather observation facility 2272
Distance of event from weather observation facility (units?) 19
Time Zone of the weather observation EDT
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) 22
Dew Point at event time (in degress fahrenheit) 1
Wind Direction (degrees magnetic) 200
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 8
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.84
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 2
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 21503
NTSB Notification Source NTSB CC
NTSB Notification Date May 10 2006 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record May 29 2007 12:24PM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office Allegheny, West Mifflin, PA

Aircraft Involved

Aircraft #1

Aircraft Registration Number N5473
NTSB Number NYC06LA112
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Bulmer
Aircraft Model Lancair IV-P
Aircraft Series Identifier --
Aircraft Serial Number LIV-473
Certified Max Gross Weight 3550
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? Yes
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 Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Jul 1 2005 12:00AM
Airframe hours since last inspection 27
Airframe Hours 27
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name N5473 LLC
Aircraft Owner Street Address 22443 SW Dewey Drive
Aircraft Owner City Sherwood
Aircraft Owner State OR
Aircraft Owner Country USA
Aircraft Owner Zipcode 97140
Operator is an individual? No
Operator Name --
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 22443 SW Dewey Drive
Operator City Sherwood
Operator State OR
Operator Country USA
Operator Zip code 97140
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
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) Positioning
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code 2G9
Departure City SOMERSET
Departure State PA
Departure Country USA
Departure Time 1525
Departure Time Zone EDT
Destination Same as Local Flt --
Destination Airport Code --
Destination City --
Destination State --
Destination Country UN
Specific Phase of Flight Descent - uncontrolled
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Apr 15 2007 6:42PM
User who most recently changed record MUZD
Since inspection or accident Time of Accident
Event Location Runway Number and Location 06
Runway Length 4697
Runway Width 75
Sight Seeing flight No
Air Medical Flight No
Medical Flight --