United States of America

According to air traffic control communication and radar data, the flight was VFR over the top, approximately 7,900 feet, and requested an IFR clearance to the destination airport. The flight was issued an IFR clearance and, subsequently, was cleared for the localizer runway 03 approach. Radar data indicates that the airplane intercepted the localizer and began tracking inbound. Once the airplane reached the final approach fix, the airplane entered a shallow descent, but did not reach the MDA until after passing the missed approach point (MAP). The airplane flew past the MAP, continued to descend and over flew the runway. The final radar return was captured at 1,200 feet and one mile northeast of the airport, where the airplane was later located. The weather observation facility located at the airport reported that, 11 minutes before the accident, the winds were from 140 degrees at 6 knots, ceiling 200 feet overcast, visibility 1/4 miles in fog, temperature 45 degrees Fahrenheit and dew point 45 degrees Fahrenheit. A person who was at the airport at the time of the accident reported that the "clouds were low and visibility was poor." Toxicological testing performed on the pilot by the FAA's Civil Aeromedical Institute, Oklahoma City, Oklahoma, revealed the following: 0.121 (ug/ml, ug/g) amphetamine detected in blood, 0.419 (ug/ml, ug/g) amphetamine detected in liver, amphetamine detected in kidney, 4.595 (ug/ml, ug/g) methamphetamine detected in blood, 5.34 (ug/ml, ug/g) methamphetamine detected in liver, 3.715 (ug/ml, ug/g) methamphetamine detected in kidney, pseudoephedrine present in blood, and pseudoephedrine present in liver. The airframe and engines were examined and no anomalies were discovered that would have affected operation of the flight.

Shortly after takeoff, the airplane experienced electrical problems, including numerous tripped circuit breakers. The flight crew requested a return to airport. During the landing rollout, the lead flight attendant and air traffic control personnel reported to the flight crew that smoke was coming from the left side of the airplane; subsequently, the flight crew initiated an emergency evacuation on one of the taxiways. Examination of the airplane revealed fire damage to the left, forward areas of the fuselage, cabin, and forward cargo compartment. The greatest amount of fire damage was found just aft of the electrical disconnect panel located at fuselage station 237. There was no evidence that the drip shield normally installed over the disconnect panel was present at the time of the accident. Bluish stains caused by lavatory rinse fluid were observed on surfaces near the disconnect panel on the accident airplane and in the same areas on another of AirTran's DC-9 airplanes. Examination of one of the connectors from the disconnect panel on the accident airplane revealed light-blue and turquoise-green deposits on its internal surfaces and evidence of shorting between the connector pins. It could not be determined when the drip shield over the disconnect panel was removed; however, this likely contributed to the lavatory fluid contamination of the connectors. Following the accident, AirTran revised its lavatory servicing procedures to emphasize the importance of completely draining the waste tank to avoid overflows. Boeing issued an alert service bulletin recommending that operators of DC-9 airplanes visually inspect the connectors at the FS 237 disconnect panel for evidence of lavatory rinse fluid contamination and that they install a drip shield over the disconnect panel. Boeing also issued a service letter to operators to stress the importance of properly sealing floor panels and adhering to lavatory servicing procedures specified in its DC-9 Maintenance Manual. The Safety Board is aware of two incidents involving the military equivalent of the DC-9 that involved circumstances similar to the accident involving N826AT. Drip shields were installed above the FS 237 disconnect panels on both airplanes.

The pilot was conducting a post-maintenance test flight. An overhauled engine had been installed on the right side of the airplane, and both propeller assemblies had been subsequently re-rigged. Ground checks were satisfactory, although the right engine propeller idled 90-100 rpm higher than the left engine propeller. Test flight engine start and run-up were conducted per the checklist, with no anomalies noted. Takeoff ground roll and initial climb were normal; however, when the airplane reached about 100 feet, it stopped climbing and lost airspeed. The pilot could not identify the malfunction, and performed a forced landing to rough, hilly terrain. Upon landing, the landing gear collapsed and the engine nacelles were compromised. The airplane subsequently burned. Post-accident examination of the airplane revealed that the propeller beta valves of both engines were improperly rigged, and that activation of the landing gear squat switch at takeoff resulted in both propellers going into feather. The maintenance personnel did not have rigging experience in airplane make and model. As a result of the investigation, the manufacturer clarified maintenance manual and pilot handbook procedures.

The accident aircraft had recently had maintenance work performed on its autofeather system pressure sensing switches, due to reports of the left engine not autofeathering properly in flight. The purpose of the accident flight was to verify proper inflight operation of the autofeather system following the maintenance work on the autofeather pressure sensing switches and a successful ground check of the autofeather system. Air traffic control (ATC) communications recordings disclosed that the pilot called ready for takeoff from runway 2 approximately 1207, and requested to orbit above the airport at 8,000 feet (note: the airport elevation is 4,740 feet.) The pilot subsequently reported established in a hold above the airport at 8,000 feet approximately 1213, and was instructed by ATC to report leaving the hold. Approximately 1215, an abbreviated radio transmission, "zero five four," was recorded. The Idaho Falls tower controller responded to this call but never got a response in return from the accident aircraft, despite repeated efforts to contact the aircraft. Witnesses reported that the aircraft banked to the left, or to the west, and that it entered a spiral from this bank and crashed (one witness reported the aircraft was flying at 200 to 300 feet above ground level when it entered this bank, and that it performed a "skidding" or "sliding" motion part way through the bank, about 1 second before entering the spiral.) The aircraft crashed about 2 miles north of the airport. On-site examination disclosed wreckage and impact signatures consistent with an uncontrolled, relatively low-speed, moderate to steep (i.e. greater than 22 degrees) angle, left-wing-low impact on an easterly flight path. No evidence of flight control system malfunction was found, and a large quantity of jet fuel was noted to be aboard the aircraft. Post-accident examination of the aircraft's engines indicated that the left engine was most likely operating in a low power range and the right engine was most likely operating in a mid to high power range at impact, but no indications of any anomalies or distress that would have precluded normal operation of the engines prior to impact was found. Post-accident examination of the aircraft's propellers disclosed indications that 1) both propellers were rotating at impact, 2) neither propeller was at or near the feather position at impact, 3) both propellers were being operated with power at impact (exact amount unknown), 4) both propellers were operating at approximately 14º to 20º blade angle at impact, and 5) there were no propeller failures prior to impact. Post-accident examination of the autofeather pressure sensing switches disclosed evidence of alterations, tampering, or modifications made in the field on all but one switch (a replacement switch, which had been installed just before the accident flight during maintenance) installed on the aircraft at the time of the accident. All switches except for the replacement switch operated outside their design pressure specifications; the replacement switch operated within design pressure specifications. Examination of the switches indicated that all switches were installed in the correct positions relative to high- or low-pressure switch installations. Engineering analyses of expected autofeather system performance with the switches operating at their "as-found" pressure settings (vice at design pressure specifications) did not indicate a likelihood of any anomalous or abnormal autofeather system operation with the autofeather switches at their "as-found" pressure settings. Also, cockpit light and switch evidence indicated that the autofeather system was not activated at the time of impact. The combination of probable engine power and propeller pitch on the left engine (as per the post-accident engine and propeller teardown results) was noted to be generally consistent with the "zero-thrust" engine torque and propeller RPM settings specified for simulated single-engine practice in the aircraft Information Manual.

The airplane was destroyed on impact with trees and terrain after takeoff. A post-impact fire ensued. A courier stated that he put 14 cases and 5 bags into the airplane and that "everything took place as it normally does." A witness stated, "I heard a very low flying aircraft come directly over my house. ... It sounded very revved up like a chainsaw cutting through a tree at high speed." The accident airplane's radar returns, as depicted on a chart, exhibited a horseshoe shaped flight path. That chart showed that the airplane made a left climbing turn to a maximum altitude of 2,479 feet. That chart showed the airplane in a descending left turn after that maximum recorded altitude was attained. The operator reported the pilot had flown about 75 hours in the same make and model airplane and had flown about 190 hours in the last 90 days. The weather was: Wind 090 degrees at 7 knots; visibility 1 statute mile; present weather light rain, mist; sky condition overcast 200 feet; temperature 9 degrees C; dew point 9 degrees C. No pre-impact engine anomalies were found. NTSB's Materials Laboratory Division examined the annunciator panel and recovered light assemblies and stated, "Item '29' was a light assembly with an identification cover indicating that it was the '[Right-hand] AC BUS' light. Examination of the filaments in the two installed bulbs revealed that one had been stretched, deformed and fractured and the other had been stretched and deformed." The airplane manufacturer stated that the airplane's left-hand and right-hand attitude gyros are powered by the 115-volt alternating current essential bus. Two inverters are installed and one inverter is used at a time as selected by the inverter select switch. The inverter select switch is located on the right hand switch panel. The airplane was not equipped with a backup attitude gyro and was not required to be equipped with one. The airplane was certified with a minimum flight crew of one pilot. Subsequent to the accident, the operator transitioned "from the single pilot operation of our Fairchild Metroliner to the inclusion of a First Officer."

The airline transport rated pilot was returning an organ transplant nurse passenger to an uncontrolled, no facilities airport, with ground fog present about 0400 in the morning. The pilot had obtained two abbreviated preflight weather briefings while waiting for his passenger, and prior to departing at 0235. According to witnesses he attempted to land twice on runway 28, then he made an approach and attempted a landing on runway 10. Witnesses reported that the airport was engulfed in ground fog at the time of the approaches. They said that you could see straight up but not horizontally. The airplane collided with grape vineyard poles and canal/wash berms, about 250 feet short of the runway 10 displaced threshold. Approach charts for two airports with instrument approaches within 20 miles were found lying on the instrument panel glare shield. The passenger's car was parked at the uncontrolled airport.

During en route cruise flight at an assigned altitude of 11,000 feet (msl) in instrument meteorological conditions, the airplane impacted mountainous terrain at 5,300 feet, in wings level, descending flight. During the final 12 minutes of the flight (from 1046 to 1058 Pacific daylight time), recorded military search radar height values (primary radar returns) show the aircraft in a steady descent from 11,000 feet to 5,600 feet, where radar contact was lost. During the same time interval, recorded Mode C altitudes received at Los Angeles Air Traffic Control Center (Center) and SoCal Terminal Radar Approach Control (TRACON) indicated the aircraft was level at 11,000 feet. At 1055:49, when the pilot was handed off from SoCal TRACON to Los Angeles Center, the pilot checked in with the Center ". . . level at one one thousand." At 1057:28, the pilot asked the Center controller "what altitude you showing us at" to which the controller responded "not receiving your mode C right now sir." At 1057:37, the pilot transmitted "o k we'd like to climb to vfr on top, our uh altimeter just went down to uh fifty three hundred." The controller approved the pilot's request to climb to VFR conditions on-top and, at 1057:54, the pilot responded "roger we're out." No further transmissions were received from the aircraft. The airplane was equipped with a single instrument static pressure system with two heated static ports. The static system and static system instruments were damaged or destroyed by impact and post-crash fire sufficiently to preclude post-accident testing.

The twin turboprop airplane overran the runway, impacted two fences, and an occupied automobile after the airline transport pilot attempted to abort a takeoff. The pilot performed a rolling takeoff and was paying close attention to balancing the engine power and keeping runway centerline alignment. As the airplane accelerated, the pilot set the power above 80 percent and began an instrument scan. He then noted the airspeed indicator was reading zero with the needle resting on the peg. After a moment's hesitation, the pilot attempted to abort the takeoff by reducing the power levers to flight idle, and subsequently over the gate to ground fine. He reported to the FAA that he did not place the power controls into the reverse position. Air traffic controllers reported they observed the airplane with its nose wheel off of the ground approximately 3/4 of the way down the 4,602-foot long runway. The aircraft's left and right pitot/static systems were examined and tested after the accident, and no anomalies were noted. The pilot obtained verbal training on rejected/aborted takeoffs for the accident airplane. He obtained his type rating and 14 CFR 135 check-out in the accident airplane approximately 1 month prior to the accident. The pilot had accumulated a total of 10,867.5 hours of flight time, of which 34.7 hours were accumulated in the accident aircraft make and model. The pilot reported his total pilot-in-command flight time in the accident aircraft make and model as 20 hours, all of which were accumulated within the preceding 30 days of the accident. Examination of the airplane, the flight instruments and the pitot/static system found no explanation for the pilot reported lack of airspeed reading. The brakes were found to be fully functional. Review of the performance charts for the airplane disclosed that for the weight and ambient conditions of the takeoff, the airplane required 4,100 feet for an
accelerate-stop distance; the runway was 4,602 feet long.

The pilot reported that after rotation, he obtained a positive rate of climb. At 110 knots, with the landing gear retracted and the wing flaps at 10 degrees, he noticed a right roll, a drop in climb performance, and a drop of manifold pressure on the right engine to at least 34 inches. The left engine maintained 42 inches. The pilot decided that, due to a "very minimum climb rate, rising terrain ahead, [and] airspeed not increasing," he would land the airplane in a small field about 1/4 mile and 50 degrees to the left. The pilot abruptly lowered the nose of the airplane and raised the flaps to gain airspeed, then landed with a nose-high attitude and the landing gear partially extended. Post-accident examination of the airplane revealed there was vertical compression to the belly area, the fuselage was spilt across the top at the aft end of the cabin, and both wings were damaged, with the left wing buckled downward just inboard of the engine. Examination also revealed that a clamp on the right engine intake manifold was loose. An estimated takeoff weight placed the airplane 74 pounds over the maximum allowed of 6,200 pounds. The type certificate holder estimated that with the airplane at 6,400 pounds, climbing at 110 kts, and with a partial power loss down to 26 inches on one engine, the rate of climb should have been 1,150 fpm with flaps and landing gear up, and 830 fpm with flaps 10 degrees and landing gear down. Higher terrain was to the east, and lower terrain was to the west. Terrain elevation for a straight-out departure was 25 feet above the runway at 0.5 nm, and 70 feet above the runway at 2.8 nm. The pilot reported his total flight experience as 15,000 hours, which included 13,000 hours in multi-engine airplanes, and 30 hours in make and model, all with the preceding 90 days.

On October 10, 2000, at 1452 central daylight time, a Canadair Challenger CL-600-2B16 (CL604) (Canadian registration C-FTBZ and operated by Bombardier Incorporated) was destroyed on impact with terrain and postimpact fire during initial climb from runway 19R at Wichita Mid-Continent Airport (ICT), Wichita, Kansas. The flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as an experimental test flight. The pilot and flight test engineer were killed. The copilot was seriously injured and died 36 days later.