Texas

Crashed in unknown circumstances in trees while completing a local training flight at Fort Bliss AFB. All four crew members were rescued, among them two were injured.

While on an IFR clearance, the pilot reported to approach control that he was unable to maintain 4,000 feet msl, and did not give a reason. Shortly thereafter, the pilot contacted approach control and stated that he had "fuel starvation" in the right engine and the left engine had just quit. Radar data depicted the aircraft at an altitude of 3,400 feet. The controller asked the pilot if they were completely without power, and the pilot responded, "yes, we're now gliding." The controller gave the pilot instructions to the nearest airport, which was approximately 4.5 nautical miles away. After passing 2,100 feet, the pilot informed the controller that he would be landing short. During the forced landing, the airplane struck the top of a tree, crossed over a house, struck another tree, struck a telephone wire which crossed diagonally over a street, and then cleared a set of wires which paralleled the street. The airplane then impacted a private residence within a residential area, and a fire erupted damaging the airplane and the private residence. Ten gallons of fuel were drained from the left locker tank, which supplements the left main fuel tank. Examination of the airframe and engines did not disclose any structural or mechanical anomalies that would have prevented normal operation. Examination of the propeller revealed that neither propeller had been
feathered.

The twin-turbojet, transport-category airplane was destroyed when it departed controlled flight during descent into its final destination and impacted terrain. The flight was cleared to descend from FL 390 to 10,000 feet, and the flight crew established a 4,000-foot/minute descent. As the airplane descended through FL 219, air traffic control requested the pilot contact approach control. However, the pilot read back an incorrect frequency and spoke an unintelligible word. The controller attempted to correct the pilot; however, no additional communications were received from the flight crew. Located within a pause in the pilot's last transmission, a 1680 Hz frequency could be heard for 0.1 seconds. There are only two systems in the airplane with aural warning systems within that frequency range; the cabin altitude warning, and the overspeed warning (both systems were destroyed during the accident sequence). Shortly after the last transmission from the pilot, radar data depicted the airplane climbing back up to FL 231 before entering a steep and rapid descent. A performance study indicated that just prior to the loss of control, the airplane exceeded its maximum operating airspeed of 300 knots calibrated. However, according to the manufacturer, the airplane had been successfully flown at airspeeds up to 400 knots calibrated without loss of control. The right wing and sections of the right horizontal stabilizer/elevator separated from the airplane just prior to its impact with terrain and were located approximately 200-250 feet from the main impact crater. No anomalies with the airframe or engine were found that would have led to the loss of control. A cockpit voice recorder was installed in the accident airplane; however, it did not record the accident flight.

At 2144, the pilot contacted air traffic control and requested visual flight rules (VFR) flight following to his destination. The flight was the final leg of a four-leg trip, which the pilot had begun approximately 1120 that morning. At 2220, the flight began a slow descent toward the destination airport. Radar data confirmed that the airplane executed a steady descent, and flew a straight line course toward Graham. The final radar return occurred 37 minutes later at an altitude of 3,000 feet (radar coverage is not available below 3,000 feet), 8 miles southeast of the Graham Municipal Airport. Two minutes after the final radar return, the pilot reported to air traffic control that the flight was two miles out, and he canceled VFR flight following. No further communications or distress calls were received from the airplane. The pilot did not request or receive updated weather from the air traffic controllers during the flight. According to witnesses who lived near the accident site, they heard an airplane flying low, observed dense fog and heard the sounds of an airplane crashing. According to the nearest weather reporting station, near the time of the accident, the temperature- dew point spread was within 2 degrees, visibilities were reduced to between 3 and 4 miles in fog, and the ceiling was decreasing from 600 feet broken to 400 feet overcast. At the time of the accident, the pilot's duty day exceeded 12 hours. Examination of the airframe revealed no preimpact anomalies and that the gear was extended and the flaps were retracted. Examination of both engines revealed evidence of power at the time of impact.

The commercial pilot flew the airplane on a cross-country flight of at least 2 hours and 47 minutes before dropping of his passengers, and flew back for 2 hours and 7 minutes without refueling. The pilot reported that as the airplane turned onto final approach, the right engine began to surge. He reduced the power on the right engine and increased power on the left, but the airplane started to roll right so he elected to reduce the power on the left engine and land in an alley. Prior to impacting wires, the pilot retracted the landing gear and brought the condition levers to "cut-off." A witness observed the airplane prior to impact and noted that the "motor wasn't on." The airplane impacted power lines, a tree, a natural gas meter, two residences, and a fence. The fuel tanks were compromised during the impact sequence, and the fire department sprayed the area with fire retardant foam. A test of the water runoff revealed "negative results for petroleum risk." Examination of both engines' fuel lines between their respective firewalls and fuel heaters, and fuel pumps and fuel control units revealed that they were void of fuel.

The airplane's fuel tanks were fueled from a self serve fuel pump with 63 gallons of fuel prior to departure. The pilot initiated the takeoff roll from runway 30 with a 10 knot tailwind. The airplane was reported to have used the entire length of the runway during the takeoff roll. The airplane became airborne, attained a height approximately 100 feet agl, entered a descent, and subsequently, impacted the ground. A post accident fire consumed the airplane. Immediately following the accident, the pilot reported to local authorities that "he was leaving the airstrip and the plane stalled due to lack of airspeed." The 3,000-foot runway rises rapidly at its north end, such that the departure end of runway 30 was 50 feet higher than the approach end. At the time of the accident, the wind was from 130 degrees at 10 knots and the density altitude was 4,136 feet. Examination of the engine did not reveal any anomalies that would have precluded its operation prior to the accident.

During landing touchdown, following a stabilized approach, the right main landing gear failed. The airplane remained controllable by the pilots and came to a stop on the runway, resting on its right wing. The DFW Fire Department arrived at the accident site in 35 seconds and, following communication between the airplane's Captain and Fire Department's Incident Commander, it was decided that an emergency evacuation of the airplane was not necessary. Examination revealed that the right main gear's outer cylinder had fractured allowing the lower portion of the gear (including the wheel assembly) to separate from the airplane. Research, examination & testing of the cylinder revealed that a forging fold was introduced into the material during the first stage of its forging process. The first stage is a hand operation, therefore the quality is highly dependent on the person performing the hand operation. Following the first landing, the forging fold became a surface breaking crack, due to the normal loads imposed during landing. Although growth of the fatigue crack was suppressed by crack blunting, high load landings resulted in growth of the fatigue crack. Subsequently, the landing gear failed when the crack had reached a critical length. Additionally, the airplane's maintenance records were reviewed and no anomalies were found.

Visual meteorological conditions prevailed for the planned cross-country flight for which the pilot obtained a weather briefing, filed an IFR flight plan, and received an ATC clearance. Approximately 8 minutes after takeoff, radar indicated the airplane was at 11,200 feet msl, heading 241 degrees, with a ground speed of 180 knots. No distress calls or additional communications with the pilot were recorded, and radar contact was lost. The airplane impacted the ground in an uncontrolled descent. The right wing tip tank separated from the airplane and was found 0.18 nautical miles from the main wreckage. The teardown and examination of both engines disclosed that the type and degree of damage was indicative of engine power section rotation and operation at the time of impact. There were no complete systems intact at the accident site due to the impact sequence and post-impact fire which consumed the aircraft. The landing gear and flaps were found in the retracted position. The portion of the right propeller shaft coupling found at the site was fractured through 360 degrees. Metallurgical examination revealed that the propeller shaft coupling failed in fatigue. The presence of the fatigue cracks indicated the coupler fractured in fatigue in service, and the fatigue cracks were not the result of ground impact. The circumferential fracture intersected the ends of several internal spline teeth. The origin of the fatigue crack could not be determined because of severe corrosion damage on the fracture surface. Fatigue propagation was in the aft direction and from the inside to the outside of the coupling. The engine core rotating components would have bee free to rotate when uncoupled from the propeller shaft. The maintenance records indicated that the failed coupling had accumulated approximately 4,000 hours since new, and 1,250 hours since engine overhaul in 1989. Since 1990, as a result of fatigue fractures, the manufacturer introduced several design changes for the propeller shaft coupling via optional Service Bulletins to be accomplished at the next access or hot section inspection (HSI). Impact and thermal damage of the right propeller precluded a determination of the in-flight blade angles. The calculations by the airplane manufacturer indicated that "the [intact] airplane was capable of continued flight" with the right propeller feathered, and that the "airplane can keep attitude, but cannot climb and cannot maintain altitude" with the right propeller in the flat pitch or wind milling positions, respectively. Metallurgical examination of the component brackets and associated bolts from the right tip tank revealed the separation of the tip tank resulted from a single-event overstress fracture of both the forward and aft tank attachment fittings. Calculations showed that a 3.763 radians per second (35.9 RPM) spin rate would cause the failure of the forward wing fuel tank attachment fitting. There had not been a previous in-flight separation of a wing tip fuel tank on this model airplane.

Upon arrival at the destination airport, the commercial pilot of the Part 135 cargo flight reported to the tower that he was 7 miles to the east, intending to land on runway 13. Subsequently, the pilot reported that he would circle the airport a few times "because he was having trouble with his autopilot." After circling, the pilot positioned the airplane on final approach to runway 13. The pilot of another airplane in the traffic pattern observed the accident airplane on a "one to two mile final, in a normal flight attitude but possibly a little low." After looking at her instruments for several seconds, she made visual contact again and observed the airplane impact the ground with the "tail of the aircraft falling forward on top of a fence." She further stated that all of the radio transmissions from the accident airplane were "calm and completely un-alarmed prior to the accident." Another witness, who was located at a fixed base operator at the airport, observed the airplane turn onto final. He stated that the airplane "suddenly stalled and slammed into the ground from about two hundred feet." The 1,140 hour pilot had accumulated a total of 70 hours in the Cessna 402. The airplane was found to be within its prescribed weight and balance limitations at the time of the accident. Ground impressions and airframe deformations indicated that the impact angle was approximately 25 degrees nose down on a magnetic heading of 155 degrees with the landing gear extended and the flaps partially extended. A post-impact fire destroyed the airplane. Flight control continuity was established from the aft section of the cockpit to the rudder and elevator flight control surfaces. The elevator trim tab (located on the right elevator) was measured with a protractor and found to be in the 28 degrees tab-up position (aircraft nose down). According to the airplane manufacturer's specifications, the maximum tab-up travel limit (when connected) is 5 degrees. The trim tab would not move freely by hand forces and appeared to be jammed. The elevator skin was cut open (top side) to observe the trim tab connecting hardware. It was observed that the clevis end of the trim tab actuator rod was wedged against the front spar of the elevator's internal structure. Additionally, the bolt which connected the clevis end of the tab actuator rod to the actuator screw, was missing. After further inspection, neither the bolt nor the nut were found in the cavity of the elevator structure or the surrounding area. The clevis end of the actuator rod and the actuator screw were not damaged, and no impact damage was apparent on the trim tab. The operator's maintenance records showed that the right elevator had been replaced 10 flight hours prior to the accident.

The pilot and 21 jumpers were aboard the airplane for the local skydiving flight. The airplane took off to the north on the wet grass runway. Jumpers reported that during the initial takeoff climb, the aircraft assumed a "very steep angle of attack," and described the pilot "winding the wheel on the lower right side of the chair clockwise, frantically," and "busy with a wheel between the seats." The airplane impacted trees and terrain approximately 250 yards east of the runway. The pilot reported that the "airplane flew through a dust devil" and did not have enough altitude for a complete recovery. The pilot stated the winds were northerly at 6 to 8 knots with "extreme" turbulence. The nearest weather observation facility reported clear skies with calm wind. Takeoff weight and center of gravity (CG) were calculated at 9,118.05 lbs and 161.92 inches. The AFM listed the maximum gross weight at 8,000 pounds and the aft CG limit at 152.2 inches. Further, an AFM WARNING stated: C. G. POSITION OF THE LOADED AIRCRAFT MUST BE CHECKED AND VERIFIED PRIOR TO TAKE-OFF, AND APPROPRIATE TRIM SETTINGS SHOULD BE USED; OTHERWISE ABNORMAL STICK FORCES AND POSITIONS MAY RESULT. The elevator trim wheel is located on the righthand side of the pilot's seat. Post-accident examination of the airplane revealed that there were 16 seatbelts in the cabin section and 2 seatbelts in the cockpit. Additionally, a placard installed in the cockpit stated, in part, THIS AIRPLANE IS LIMITED TO THE OPERATION OF NINE PASSENGERS OR LESS. Regarding the discrepancy between the placarded 9 passenger limit and the 21 jumpers aboard, the pilot stated that parachute jumpers are not considered to be passengers and therefore, he did not have to comply with the placarded limit.