SJ-30 Test Aircraft Crashes April 26, 2003 Near Loma Alta, Texas

HISTORY OF FLIGHT - From NTSB Preliminary Report

On April 26, 2003, at 1005 central daylight time, a Sino-Swearingen Aircraft Corporation (SSAC) SJ30-2, N138BF, serial number 002, was destroyed when it impacted terrain near Loma Alta, Texas. The certificated airline transport pilot was fatally injured. Visual meteorological conditions prevailed for the flight, which departed on an instrument flight rules flight plan from San Antonio International Airport (SAT), San Antonio, Texas, at 0911. The local test flight was conducted under 14 CFR Part 91.

According to company flight test personnel, the mission, flight test number 231, was the second in a series of flights to complete SSAC Report 30-2222, "Flight Flutter Certification Test Plan for SSAC SJ30-2" requirements.

The first flutter mission, flight test number 230, was flown one day earlier with the same pilot onboard. The pilot terminated the flight after an uncommanded roll to the left, and a subsequent discrepancy was noticed between his displayed airspeeds and those reported by a chase plane pilot.

After the flight, the pilot realized that he had incorrectly set up the airspeed display in the test airplane. When he thought he had completed a test point at indicated Mach 0.860, he had actually completed it at indicated Mach 0.878.

The pilot also reported to flight test personnel that during the flight, he had felt a "rumble" in conjunction with the left roll at, according to his notes, indicated Mach 0.855. Immediately beneath the left roll comment, he had written, "Rudder input?"

According to the project's flutter consultant Designated Engineering Representative (DER), a possible explanation for the rumble was Mach buffet. However, to confirm that there wasn't a mechanical problem with the airplane, flight test personnel assigned a second SSAC pilot as a backseat chase plane observer for the next (accident) flight.

The chase airplane was a contracted Northrop T-38, N638TC, with a pilot and the second SSAC test pilot onboard during the accident flight. The accident flight was also being monitored in a telemetry van in Rock Springs, Texas, by the flutter consultant and three SSAC personnel.

Prior to the test flight, a mission briefing, led by the accident test pilot, was conducted via conference call between the San Antonio-based personnel and the telemetry van personnel. According to a briefing participant, all of the flight test cards were covered, "including the test limitations, test set-up, test points, weight and balance, airspace operational considerations, aircraft limitations, maintenance actions since last flight, instrumentation status, and chase aircraft procedures."

An "SSAC Flight Briefing Guide" was also utilized, which included a review of hazard analyses, and abnormal/emergency procedures. During the briefing, the test pilot stated that he was responsible for safety of flight.

The flutter consultant also noted that he had, during previous discussions, advised that for the purpose of flutter testing, if the pilot ran out of aileron/elevator trim, the tests could still be completed, even if the pilot had to hold aileron/elevator force to steady the airplane. He further stated, however, that the continuance of the testing would never override the pilot's decision as to whether the control forces were unacceptable or hazardous.

According to the flutter consultant, after takeoff, the airplane climbed to 39,000 feet and set up for a shallow dive along a 090-degree track for flight test point 1-14 (indicated Mach 0.884).

A telemetry lock was then obtained. However, when the airplane reached indicated Mach 0.875, the test pilot called "Mark" on the radio to duplicate the previous day's test point.

After the "Mark" was received, the pilot initiated a single pulse input to the elevator. After checking the telemetry strips, the consultant then gave a "Go" for a single pulse to the aileron, followed by another "Go" for a single pulse to the rudder. Telemetry van personnel noted that all the modes excited were "well damped."

Telemetry van personnel also reported that after the pulses were completed, the test pilot stated that the uncommanded roll to the left (which was experienced on the previous flight), did not occur. There was also no mention of a rumble. In addition, the chase plane pilots confirmed that there were no mechanical anomalies evident on the accident airplane.

According to the flutter consultant, the accident airplane subsequently turned back to the west and began to climb back to 39,000 feet to set up for the dive to the 1-14 point along a 270-degree magnetic track. Discussion between the pilot and telemetry van personnel indicated that the 1-14 point might be the last one of the mission due to fuel concerns, especially for the chase airplane.

Following telemetry lock, the airplane began a shallow dive. According to most of the participating personnel, prior to reaching the test point of indicated Mach 0.884, the pilot reported that he had put in full trim and couldn't let go. At indicated Mach 0.884, the pilot called "Mark." Each control surface was again pulsed by the pilot, and the responses were again "well damped."

Following the final pulse, the pilot was cleared to the next test point, 1-15 (indicated Mach 0.894), "if flight conditions permitted the test pilot to do so." However, the pilot did not acknowledge the clearance, but instead, reported that the airplane was rolling to the right, and he couldn't stop it. Telemetry was lost about 20 seconds later.

The chase airplane pilot confirmed that after the 1-14 test point had been completed, the test pilot was cleared to accelerate to the 1-15 test point, if able. At that time, the test airplane appeared to be in a shallow right bank with the chase airplane less than 500 feet above and 500 feet behind it.

"Very soon thereafter," about 30,000 feet, the test airplane began rolling to the right. The rolling maneuver appeared to be stable, and continued unchanged until ground impact. The test airplane appeared to remain intact throughout the event, and no parts were seen departing the airframe. After the test airplane began to roll, and the test pilot stated that he couldn't stop it, the chase pilot called, "get out" twice. The test pilot responded that he couldn't get out, that there were too many "g's."

The second SSAC test pilot, in the back of the chase airplane, also noted that the accident sequence began after the completion of the 1-14 test point. During the sequence, the chase airplane was not close enough to observe the test airplane's control positions.

The second test pilot observed the test airplane's nose to be "a little low," and in an approximately 30-degree right bank after test point 1-14 was completed. After a few seconds, the test airplane entered a "barrel-roll type maneuver" to the right, then continued to roll, and increased its dive angle until ground impact.

When the second test pilot saw the first roll, his first thought was, "what did he do that for?" Then he saw that the airplane "came around and made another barrel roll. It was not around a point like an aileron roll; and it was not real fast; it looked lazy." The chase pilot then mentioned the roll to the accident pilot, who replied that he couldn't stop it. The accident pilot did not say anything further about how the airplane was performing, or what he was experiencing.

PERSONNEL INFORMATION

The pilot held an airline transport pilot certificate, with ratings for the Boeing 707, 727, and 747, and Airbus 300. He was also a retired Navy pilot with combat experience in the Vought F8J Crusader, and had subsequent flight test experience with several major aerospace manufacturers. His latest Federal Aviation Administration second class medical certificate was issued on July 3, 2002. At the time, the pilot reported 12,000 hours of total flight time.

According to SSAC records, the pilot joined the company in 1997. Prior to the accident flight, the pilot had accumulated 271 flight hours in the accident airplane, and 331 flight hours in SSAC airplane number 001.

According to a technical services agreement, the flutter consultant DER was hired to "provide oversight and guidance in the execution and documentation of flutter analysis" for certification compliance with FAR 23. In conjunction with the agreement, the consultant was "given authority as director of test preparation, test conduct, and analysis of results."

AIRCRAFT INFORMATION

The accident airplane, serial number 002, was a non-type-certificated experimental research and development aircraft. On September 24, 2002, the Federal Aviation Administration (FAA) issued the airplane a Special Airworthiness Certificate with Experimental Operating Limitations for the Purpose of Research and Development.

The airplane was inspected using an Approved Aircraft Inspection Program (AAIP) titled "SJ30-2 Inspection Procedures Aircraft S/N 002, Report Number: QA-INSP-500 (QA-500)." Data accumulated during the airplane's design and operational testing was analyzed to formulate the inspection program requirements.

Inspections included the First Flight of Day Inspection, Next Flight Inspection, After Last Flight Inspection, Periodic/Phase Inspections (A, B, C) and Special Inspections. The Periodic/Phase inspections were accomplished at 100-hour intervals. Inspections were recorded on the Flight Test Work Order (FTWO).

Aircraft maintenance manuals had not been developed for the airplane. Maintenance was accomplished by FAA-certificated technicians using aircraft drawings and specifications in conjunction with vendor component maintenance manuals. Maintenance work was also recorded on the FTWO.

The last Periodic/Phase Inspection was a "B" Check, accomplished on January 14, 2003, at 284.2 hours. A First Flight of Day Inspection was accomplished on April 26, 2003, for the accident flight, at 315.9 hours.

METEROLOGICAL INFORMATION

Weather, recorded at an airport about 35 nautical miles to the south, included clear skies, winds from 330 degrees true at 10 knots, and 10 miles visibility.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located at 29 degrees, 52.37 minutes north latitude, 100 degrees, 57.65 minutes west longitude, about 250 degrees magnetic, 10 nautical miles southwest of Loma Alta, Texas, and 350 degrees magnetic, 30 nautical miles north of Del Rio, Texas.

The accident site was located in a remote area of sparsely vegetated plateaus and canyons, at an elevation of 1,741 feet, near the top of one of the plateaus. The main crater was cut almost straight down, about 5 feet, into a sandstone formation. There were additional cuts, consistent with wing positions, oriented along a 085/265-degrees magnetic axis.

The wreckage was fragmented, with debris spread over an area of approximately 9 acres, dispersed 360 degrees around the impact crater. Evidence of all flight control surfaces was found at the scene. Slat tracks were identified; however, no slat structures were identified in the debris field. There was no evidence of in-flight fire or in-flight failure of structural elements, and all fracture surfaces examined exhibited evidence of static overload. Control continuity could not be confirmed due to the severity of the impact damage.

ADDITIONAL INFORMATION

The airplane was equipped with a trailing cone for static air pressure and a nose boom for dynamic air pressure. The combined inputs resulted in a "reference system airspeed." The pilot would have had to operate two cockpit switches to be able to display reference system airspeed. Failure to do so would have resulted in him reading a lower airspeed, generated from the airplane's internal airspeed indicating system.

The telemetry van was receiving reference system airspeed. One of the telemetry personnel stated that as the accident sequence approached, the airplane's airspeed readout was consistently between Mach 0.881 and 0.882. He subsequently noted that he did not believe the airplane exceeded Mach 0.882 before the telemetry signal was lost.

Hard drives containing over 450 flight parameters were onboard the airplane. The hard drives were recovered; however, their condition precluded any data recovery.

The telemetry data included 27 parameters, most of which were accelerations. Additional parameters included Mach, altitude, calibrated airspeed, magnetic heading, ventral rudder position, rudder position, and elevator position. The telemetry data was forwarded to the Safety Board for review.

Click thumbnails below for photos of the crash site