DFW05LA037

According to a witness, who was in a field approximately 1 mile north of the accident site, the airplane was performing aerobatic maneuvers in the area when the airplane flew straight up into the air, and then "fell over into a flat spin." At this point, the witness estimated that the airplane at an approximate altitude of 5,000 feet above the ground. The witness heard the engine "revving up" as the airplane descended behind a tree line. He then heard the airplane impact the ground and the engine stop running. The 1,040-hour pilot, who was occupying the rear seat of the tandem seating experimental bi-plane, purchased the airplane during the first week of July 2004. Post-accident calculations revealed that the airplane was over maximum gross weight and the center of gravity (CG) was aft of the rearward limit. According to page 3-8 of the Christen Eagle II Airplane Flight Manual, "Any particular Christen Eagle II aircraft will recover from any spin type using standard recovery techniques ONLY IF THE AIRCRAFT IS PROPERLY BALANCED. The CG of the aircraft must be within design limits to ensure safe spin recovery. Any aircraft can be dangerously loaded (CG beyond design limits) making spin recovery extremely difficult or impossible. Weight and balance considerations must be taken seriously and pilots must be absolutely certain that the flight CG of their aircraft is within design limits."

History of flight

On December 12, 2004, approximately 1656 central standard time, a Crosley Christen Eagle II experimental bi-plane, N222CE, was destroyed when it impacted terrain following a loss of control while maneuvering near Morris, Oklahoma. The private pilot and pilot-rated passenger were fatally injured. Visual meteorological conditions prevailed throughout the area, and a flight plan was not filed for the personal flight that was conducted under the provisions of 14 Code of Federal Regulations Part 91. The local flight departed from the Okmulgee Municipal Airport (OKM), near Okmulgee, Oklahoma, approximately 1630.

According to a witness, who was in a field approximately one mile north of the accident site, the airplane was performing aerobatic maneuvers in the area when the airplane flew straight up into the air, and then "fell over into a flat spin." At this point, the witness estimated that the airplane was at an approximate altitude of 5,000 feet above the ground. The witness heard the engine "revving up" as the airplane descended behind a tree line. He then heard the sound of the airplane impacting the ground and the engine stop running.

Personnel information

The 54 year-old pilot obtained a private pilot certificate with a rating for airplane single engine land on December 21, 1985. His most recent Federal Aviation Administration (FAA) third class medical certificate was issued on March 19, 1985, and expired on March 31, 1987. It displayed the restriction "Not valid for night flying or by color signal."

A review of the pilot's logbook revealed that as of July 16, 1987, the pilot had accumulated a total of 240.7 hours of flight time. There were no logbook entries made past this date; however, a close friend of the pilot estimated that the pilot had accumulated approximately 1,040 hours of flight time.

The 46 year-old pilot-rated passenger obtained a private pilot certificate with a rating for airplane single engine land on February 24, 1997. His most recent Federal Aviation Administration (FAA) first class "limited" medical certificate was issued on September 10, 2002, at which time he reported having flown a total of 1,100 hours. The medical certificate was "limited" due to a medicated hypertension condition and displayed the restrictions "Must wear lenses for distant and possess glasses for near vision."

Aircraft information

The 1982-model Crosley Christen Eagle II, serial number Crosley-0001, was an amateur-built, experimental bi-plane, with fixed landing gear, and was configured to carry a maximum of two occupants in a tandem-seating configuration. The airplane was powered by a normally aspirated, direct drive, air-cooled, horizontally opposed, fuel-injected, four-cylinder Lycoming IO-360-A1D engine (serial number L-22680-51A), rated at 200 horsepower at sea level.

Review of the airframe and engine logbooks, revealed the airplane's most recent 100-hour inspection was on June 1, 2004, at a total aircraft time of 568.3 hours.

The pilot had purchased the airplane from Brannan Leasing, Inc., of Lake Mary, Florida, during the first week of July 2004.

Meteorological information

At 1753, the automated weather observing system at OKM reported wind from 010 degrees at 9 knots, gusting to 16 knots, 10 statute miles visibility, a clear sky, temperature 57 degrees Fahrenheit, dew point 35 degrees Fahrenheit, and an altimeter setting of 30.09 inches of Mercury.

Wreckage and impact information

The airplane appeared to have impacted the ground at a 45-degree nose-down attitude. The engine and propeller were found buried in the terrain. The wings and cockpit area were crushed, and the tail section of the airplane remained relatively intact. Examination of the airplane by an FAA inspector revealed no pre-impact anomalies, and flight control continuity was established.

Medical and pathological information

The Office of the Medical Examiner of Tulsa County, Tulsa, Oklahoma, performed autopsies on the pilot and the pilot-rated passenger on December 13, 2004. Multiple blunt trauma was determined to be the cause of death for the pilot and pilot-rated passenger.

Toxicological testing was performed on specimens of the pilot by the FAA Toxicology Accident Research laboratory, Oklahoma City, Oklahoma. Acetaminophen and Deiphenhydramine were detected in the pilot's urine and blood.

Tests and research

The pilot was occupying the aft seat of the tandem-seating configuration. According to his autopsy report, his weight at the time of the accident was 268 pounds. The pilot-rated passenger was located in the forward seat of the tandem-seating configuration. According to his autopsy report, his weight at the time of the accident was 225 pounds. According to a friend of the pilot, the airplane contained approximately 11 gallons (66 pounds) of fuel prior to take-off and had flown for approximately 30 minutes prior to the accident.

The airplane departed from OKM approximately 1630, and the accident occurred at approximately 1656. Based on a fuel burn of between 8.3 and 9.6 gallons per hour, the airplane would have held approximately six gallons (36 pounds) of fuel or less at the time of the accident.

According to page 1-9 of the Christen Eagle II Airplane Flight Manual, the rearward center of gravity limit for acrobatic flight is 99.60 inches (26.5% mean aerodynamic chord [MAC]) at a maximum gross weight of 1,520 pounds.

A weight of 1,589 pounds inches with a center of gravity of 101.3349 inches aft of the datum are the airplane's estimated weight and balance at the time of the accident. These calculations showed the airplane to be over maximum gross weight by 69 pounds and aft of the rearward center of gravity limit by 1.7349 inches. The factors included in this calculation were the empty weight of the aircraft (1,060 pounds, 89.1 inches aft of the datum), the pilot's weight (268 pounds, 143.37 inches aft of the datum), the pilot-rated passenger's weight (225 pounds, 111.32 inches aft of the datum), and 36 pounds of fuel (36 pounds, 86.25 inches aft of the datum).

In addition, as fuel was burned, the center of gravity moved progressively aft of the datum.

Additional information

According to page 3-8 of the Christen Eagle II Airplane Flight Manual, "Any particular Christen Eagle II aircraft will recover from any spin type using standard recovery techniques ONLY IF THE AIRCRAFT IS PROPERLY BALANCED. The CG of the aircraft must be within design limits to ensure safe spin recovery. Any aircraft can be dangerously loaded (CG beyond design limits) making spin recovery extremely difficult or impossible. Weight and balance considerations must be taken seriously and pilots must be absolutely certain that the flight CG of their aircraft is within design limits."

The wreckage was released to the owner's representative on December 15, 2004.