On June 27, 2006, about 1030 eastern daylight time, an Aerial Productions International, Acrojet Special, N23AP, was destroyed following a collision with trees during an approach to Ocean City Municipal Airport (OXB), Ocean City, Maryland. The certificated commercial pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local test flight, conducted under 14 CFR Part 91. Use your browsers 'back' function to return to synopsisReturn to Query Page
After being prepared for its flight by company personnel and the pilot, the airplane departed OXB at approximately 1010 and proceeded to a designated test area to perform airborne testing for a customer. Upon arrival at the designated test area the pilot was instructed by radio to initiate the planned testing, however; during the first of his four scheduled test runs, light rain began to fall at OXB. Although visual meteorological conditions still prevailed, the pilot was directed by his company operations to return as a safety precaution.
After arrival in the airport area, the pilot turned onto a 5-mile final approach and made a low pass down runway 14 for data collection purposes. He then joined the left downwind leg of the traffic pattern, and transmitted his position on the unicom frequency for the airport. A few seconds later the pilot also gave a position report to another test airplane that he was "turning base leg," and then transmitted his position on final approach.
A company employee, who observed the airplane moments before impact, stated that he saw the airplane on a low, level, final approach above the trees, which bordered the approach end of the runway. Though the airplane appeared low, he assumed it had cleared the trees; however, approximately two seconds later, he observed what appeared to be a plume of black smoke rise from the trees.
A witness driving in the local area at about the time of the accident also observed the airplane on final approach. After hearing what he described as a "roar," he turned, looked, and saw that the airplane was descending, and moving forward at a "high rate of speed."
The accident occurred during the hours of daylight. The wreckage was located at 38 degrees, 19.044 minutes north latitude, and 75 degrees, 07.903 minutes west longitude.
According to Federal Aviation Administration (FAA) records, the pilot held a commercial pilot certificate with multiple ratings including airplane single-engine-land and instrument airplane. His most recent FAA second-class medical certificate was issued March 1, 2006. According to company records, the pilot had accrued 9,600 total hours of flight experience, with 100 hours in the accident airplane make and model.
According to FAA and maintenance records, the accident airplane was a single seat, low wing turbojet manufactured in 1989. The airplane's most recent condition inspection was completed on August 30, 2005. At the time of the accident, the airplane had accrued 452 total hours of operation.
According to the pilot of a preceding flight, which arrived at the airport at approximately 1030, he had experienced light turbulence on the final approach to runway 14.
A weather observation taken about 9 minutes after the accident, at OXB, recorded the winds as 160 degrees at 7 knots, visibility 6 miles in light rain and mist, few clouds at 1,500 feet, broken clouds at 2,600 feet, temperature 71 degrees Fahrenheit, dew point 70 degrees Fahrenheit, and an altimeter setting of 30.13 inches of mercury.
WRECKAGE AND IMPACT INFORMATION
The airplane came to rest, right side up in a wooded area. A majority of the airplane was consumed by fire. The perimeter burn area was about 10 feet wide near the area of the cockpit and transitioned to a 25-foot wide area near the rear portion of the airplane. Broken limbs and branches were present along the flight path, and a tree strike was evident on a pine tree 75 feet from the main wreckage, approximately 85 feet up the trunk. Jet fuel was also present in the unburned areas along the flight path between the trees.
Examination of the wreckage revealed that the landing gear was in the down position, and the wing flaps were in the third notch (45-degree) position. The thrust attenuator was found partially deployed.
Examination of the cockpit revealed that, the electronic control unit switch was on, and the engine mode switch was in the normal run/start position. The left and right battery master switches were on, the electronic flight information system (EFIS) switch was on, and the attitude and heading reference switch was on.
No evidence of any preimpact malfunctions of the airplane or engine were discovered.
MEDICAL AND PATHOLOGICAL INFORMATION
A postmortem examination was performed on the pilot by the State of Maryland's Office of the Chief Medical Examiner.
Toxicological testing of the pilot was conducted at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma.
TESTS AND RESEARCH
Performance data from the accident flight as well as a previous flight, was successfully downloaded from the airplane's EFIS. Parameters from the approach phases of both flights were reviewed, including barometric altitude, indicated airspeed, vertical speed, wind speed, and engine performance data.
On the accident flight, the airplane's rate of descent varied between 1,400 to 1,600 feet, versus the 700 to 1000 feet per minute for the previous flight. The airplane's airspeed on the final approach on the accident flight was approximately 25 knots slower than required by the airplane's training syllabus, for the airplane's weight. The data also showed that about 10 seconds prior to impact, the headwind component decreased by approximately 14 knots, and during the last two seconds of recorded data, angle of attack and engine power increased.
The airplane was equipped with a mechanically operated attenuator (thrust reverser) that, eliminated engine produced thrust when power was reduced to idle. It would produce drag when deployed and was usable both in-flight and on the ground.
On July 21, 2006, the operator, conducted a flight test in an airplane similar in configuration to the accident airplane. The object of the test was to document the difference in rates of descent in the normal approach configuration with the thrust attenuator in both the stowed, and deployed positions.
The airplane was flown by a pilot of similar weight as the accident pilot, carrying a fuel load representative of the fuel load aboard the accident airplane. During the test the performance parameters were recorded by the airplane's EFIS system. In the normal landing configuration, with the throttle reduced to near idle, the landing gear extended, the flaps in the 45-degree position, and the attenuator stowed, the airplane descended at a rate of 1,400-foot per minute. In the landing configuration, with the throttle near idle, and the attenuator deployed, the airplane descended at a rate of 2,200 foot per minute.
Landing Weight Restriction
According to the airplane's training syllabus, the pilot should always take into consideration a large change in wing loading due to a higher than normal fuel load when selecting approach speeds. For a normal landing with between 8 and 12 gallons of fuel at sea level, an approach speed of 80 to 85 knots was considered appropriate. At "high landing weights," 30 gallons of fuel, up to 100 knots indicated airspeed on approach was required. The syllabus also cautioned that, "except in emergencies, never land the aircraft with more than 30 gallons remaining."
Fuel burn calculations revealed that the airplane had about 35 to 37 gallons of fuel remaining at the time of the accident, which correlated to a 200-pound (25%) increase in landing weight.