N207JBCanadair CL-600-2B16 · 1996

On May 23, 2012, about 1547 eastern daylight time, a Canadair Challenger 601-3R (CL-600-2B16), N207JB, was substantially damaged following separation of the main passenger door near Hallendale, Florida. The air transport pilot and commercial-rated co-pilot were not injured. The airplane was registered to a corporation and was operated by Majestic Jet Inc. under the provisions of 14 Code of Federal Regulations Part 91 as a positioning flight. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed. The flight originated at Opa Locka Airport (OPF), Opa Locka, Florida at 1543 and was destined for Pompano Beach Airpark (PMP), Pompano Beach, Florida.

The pilot reported in a written statement that, about 3 minutes into the flight, a "loud bang" was heard, a rush of air entered the cabin, and it became evident that the main cabin door had separated from the airplane. The flight was about 4 nautical miles (nm) south of Fort Lauderdale-Hollywood International Airport (FLL) at the time, so he elected to land the airplane there. He stated that the noise in the cockpit was so loud that they could not hear on the radio. The pilot landed the airplane on runway 10L without further incident.

The co-pilot reported in a written statement that, during ground operations, he closed the main passenger door and checked for a green light to ensure that it was secure. He performed the takeoff and was at the controls when the door separation occurred. The pilot took over the controls and performed an emergency landing on runway 10L at FLL.

In an interview with a Federal Aviation Administration (FAA) inspector after the accident, the co-pilot reported that he "believed" that the door warning lights were working, but he could not positively recall seeing the green "Door Safe" light illuminated after closing the door. He also did not remember activating the warning system "Recall" switch prior to takeoff.

Ramp security video footage revealed that a crewmember entered the airplane through the main passenger door, the door closed, and then the door momentarily opened partially and closed again prior to departure. When questioned about this, the co-pilot reported that he re-closed the door because it did not secure on the first attempt.

The pilot held an airline transport pilot certificate with type ratings in the Cessna CE-500, Canadair CL-600, Boeing B747, McDonnell Douglas DC-10, and Gulfstream G-IV. He reported 12,300 hours total flight time, including 3,500 hours in the same make and model as the accident airplane.

The co-pilot held a commercial pilot certificate with ratings for airplane single engine land, airplane multiengine land, and instrument airplane. He also held a flight instructor certificate for airplane single engine land, airplane multiengine land, and instrument airplane. He reported 2,550 hours total flight time, including 65 hours in the same make and model as the accident airplane.

According to the FAA inspector, the co-pilot was hired by the operator on October 21, 2011. He was assigned to the CL-600 in February, 2012. Prior to his employment with the operator, he did not have any experience on pressurized or turbine-powered aircraft. He completed initial in-house training on the airplane on February 25, 2012, and that training was administered by the pilot. The co-pilot stated that he had received no formal training on the CL-600 other than that administered by the pilot. The training records did not specifically indicate any training on the operation of the main cabin door. The inspector's review of flight log information indicated that the co-pilot had logged 14 flights as a required crewmember, with a total flight time of 19.9 hours in the same make and model as the accident airplane.

The airplane was a low wing, retractable tricycle landing gear, transport category airplane. It was equipped with two General Electric CF34-3A1 engines.

The airplane arrived for maintenance at the Bombardier Hartford, Connecticut facility on June 20, 2008 and departed on January 5, 2012. Five repairs were documented in the area of the main passenger door, including a pressurization leak when the cabin was pressurized and a failure of the main door closed green light (PASS DR READY light) to operate. The repairs were documented and the airplane was eventually released for service. The maintenance entries and corrective actions are located in the Bombardier Field Notes, contained in the public docket for this investigation.

The 1550 surface weather observation for FLL included wind from 110 degrees at 10 knots, visibility 10 miles or better, few clouds at 2,000 feet, temperature 28 degrees C, dew point 22 degrees C, and altimeter setting 29.87 inches of mercury.

The airplane was a low wing, retractable tricycle landing gear, transport category airplane. It was equipped with two General Electric CF34-3A1 engines.

The airplane arrived for maintenance at the Bombardier Hartford, Connecticut facility on June 20, 2008 and departed on January 5, 2012. Five repairs were documented in the area of the main passenger door, including a pressurization leak when the cabin was pressurized and a failure of the main door closed green light (PASS DR READY light) to operate. The repairs were documented and the airplane was eventually released for service. The maintenance entries and corrective actions are located in the Bombardier Field Notes, contained in the public docket for this investigation.

The main passenger door and associated hardware were found on a golf course at Hallendale, Florida. The impact site coordinates were N 25 59.31, W 080 07.87. Impact marks on the ground were consistent with the top of the door striking the ground first. The door sustained structural damage from ground impact.

An examination of the airframe, including the forward and aft upper latch spigots, forward and aft cams (pull in lever), forward and aft stops, forward and aft rollers, forward and aft upper tension buttons, forward and aft center latch spigots and proximity switches, and forward and aft lower tension buttons showed no evidence of visible anomalies or structural failure. The door's mechanical interface (hinge) was found severed. The door's electrical harness interface was found damaged as a result of the door leaving the airframe in flight. About two feet of electrical wiring were found dangling from connector P2MB. The severed wires contained four power wires that were exposed and were free to contact the airframe in flight. According to the manufacturer, contact with the airframe could create a short circuit and potentially trip circuit breakers CB-D17 and CB-B160, integral to the door warning system. These two circuit breakers were found open during the post-accident examination of the cockpit.

An examination of the external fuselage revealed a puncture in the skin that was similar in size and shape as the door pull out handle. The location was consistent with the pull out handle being in the open position when the puncture occurred. The door pull out handle exhibited a bend of approximately 20 degrees opposite of its contour. The handle was found in its stowed position with the bend standing out and was difficult to extend when manipulated by hand. Its linkage to the internal and external handles was severed from tension loads.

A horizontal impression was found on the fuselage skin that was consistent in location, size and shape with the door's external handle. The horizontal orientation of the impression was consistent with the external handle being in the closed position after the door contact with the fuselage skin occurred. The forward end of the impression had a gouge 0.016" deep and approximately 0.700" high. The aft end of the impression had a gouge 0.005" deep, 1.950" long and 0.350" wide. The paint on the aft end of the impression was smudged consistent with motion towards the closed position.

An examination of the recovered main passenger door revealed that the upper half was crushed from ground impact. Due to the deformity of the door from ground impact, the door latch mechanism rigging was compromised and no attempt was made to establish if the door was rigged properly prior to the accident.

The forward and aft upper latch cams and proximity switches showed no evidence of visible anomalies or structural failure. The green alignment marks were present and visible. When the associated internal linkage was manipulated, the latch cams rotated in a normal manner. The forward and aft pull in levers, forward and aft tension fittings, and the forward and aft center latch cams showed no evidence of visible anomalies or structural failure. The green alignment marks on the center latch cams were present and visible.

The door internal handle showed no evidence of visible anomalies or structural failure. When operated by hand, the forward and aft center latch cams, the external handle, and the associated linkages operated in a normal manner.

Examination of the external handle revealed no evidence of visible anomalies or structural failure. When operated manually, the forward and aft center latch cams, the internal handle, and their associated linkages moved in a normal manner. When the handle was rotated to its closed position (horizontally) relative to the door, the handle stowed normally in its stowed position.

The pushrod, connecting the upper latch cams and lower latch cams, was severed at the lower rod end, with evidence of bending overstress. The rod was housed in the upper portion of the door that was crushed from ground impact. The pushrod parts were removed and forwarded to the NTSB Materials Laboratory for a detailed examination.

The VHF number 1 external antenna, located on the belly of the aircraft, was severed, with about 80 percent of the antenna missing. A round impression, consistent with the size and shape of the main passenger door support leg, was found near the right side fuselage station 394.

Minor damage was found on the right wing leading edge adjacent to the right landing light.

Aircraft Checklists

The flight crew utilized a FlightSafety International Quick Reference Handbook checklist during ground operations prior to takeoff. On page N-4, (Normal Start), checklist item number 5 stated, "Doors….Checked/Secured." On page N-6, (Before Takeoff), checklist item number 8 stated, "Annunciator….Recall."

Aircraft Systems

The following descriptions for the passenger/crew entrance door, door warning system, and master caution and warning system were obtained from the Canadair Challenger Maintenance Manual.

Passenger/Crew Entrance Door – Description

The entrance door for passengers and crew opens downward and outward and is manually controlled from inside or outside the aircraft.

Rollers are mounted on pull-in levers located on the fore and aft edges near the top of the door. Cams are secured to the fore and aft door frame in such a position to capture the rollers as the door approaches the closed position. This mechanism pulls the door into the full closed position to ease latch cam engagement.

Guide plates are mounted below the pull-in levers on the door. These plates contact rollers mounted on the door frame and centralize the door as it closes.

Four latch cams on the door rotate around four spigots on the door frame to hold the door closed. Two cams are located at the top edge of the door and one on each side at approximately the mid-point. The latch cams are rotated by a handle and a system of push rods and torque tubes. The upper cams have a detent in which a spring-loaded pawl seats. The handle assembly consists of a single-lever internal handle located on the forward side of the stair and an external handle. The external handle stows into a recess in the outer skin of the door and in this position, the recess acts as a lock for the latching mechanism.

Door Warning System - Description

The passenger/crew door warning system in the flight compartment consists of two amber lights and a green light. The amber lights indicate that the door is unlocked and not ready; the green light indicates a door ready condition. The amber unlocked and not ready conditions activate the master caution system causing the amber DOORS annunciator to come on and the master caution lights to flash.

Proximity switches are mounted at each door latch. These switches, together with a proximity switch on the external door handle, cause the passenger/crew door UNLOCKED light to go out when the latches are in the fully latched position and the external handle is stowed. A proximity switch on the inner lever causes the passenger/crew door NOT RDY light to go out when the inner lever is stowed. Microswitches in a separate circuit sense when the inner lever and external handle are stowed. A green passenger/crew door READY light comes on to indicate that the external handle and T-handle are stowed.

The PASS DR NOT RDY (passenger door not ready) amber light comes on if the door T-handle is not stowed. The PASS DR READY (passenger door ready) green light comes on when both the following microswitches are made: the door external handle stowed switch and the door T-handle stowed switch.

The PASS DR UNLKD (passenger door unlocked) amber light comes on if any of the following situations exists: the door external handle is not locked and stowed, the door center forward latch is not engaged, the door center rear latch is not engaged, the door upper forward latch is not engaged, or the door upper rear latch is not engaged.

Master Caution and Warning System - Description

The master caution and warning system serves two purposes: the first is to provide dimmable power for the aircraft system caution, warning and safe indication and advisory lights; the second is to provide an indication to the flight crew when certain system malfunctions occur. An additional indication is provided by the two flashing MASTER CAUTION PRESS TO RESET lights located on the glareshield, and by the appropriate annunciator on the 8 or 10 channel annunciator panels. The DOORS system annunciator is located on the 8 channel panel.

Annunciated caution lights cause the appropriate system annunciator on the 8 or 10 channel annunciator panel to come on and the MASTER CAUTION PRESS TO RESET lights to flash. The annunciator on the 8 or 10 channel annunciator panel identifies the system in which the malfunction has occurred.

Each annunciator legend has two lights installed side by side connected in parallel. The annunciator legend lights are reset by pressing the master caution switch/lights. Pressing the master caution switch, however, does not reset the system caution annunciators. The individual system light remains on and only goes out when the fault is cleared.

The 10 channel annunciator panel also contains a TEST/RECALL switch. When set to RECALL, the TEST/RECALL switch on the 10 channel annunciator panel applies 28 volts dc to the annunciator switch. If a system fault still exists, after resetting the master caution and warning system, the annunciator switch applies a ground to the associated annunciator legend and a control signal to the master caution control circuit. The annunciator legend comes on and the two MASTER CAUTION PRESS TO RESET lights flash. The 28 volts dc recall signal is also applied to the 8 channel annunciator panel.

Cabin Pressurization System

The cabin pressurization mode selector was in the AUTO mode and the EMER DEPRESS switch was not selected.

The cockpit voice recorder (CVR) and flight data recorder (FDR) were forwarded to the NTSB Vehicle Recorders Laboratory in Washington, DC for readout and examination.

The CVR was a L-3/Fairchild FA2100-1020, serial number 000244915. The two-hour recording contained good quality audio information. The unit was undamaged and the audio content was extracted without difficulty. A CVR group was formed, including the CVR Group Chairman and representatives from Bombardier and Majestic Jet.

The entire recording was not transcribed. The transcription began with the sound of a thunk and click, similar to a main cabin door closing, at 15:31:38 (HH:MM:SS). Three seconds later, a second click and thunk could be heard, consistent with the main cabin door closing and latching. There was no mention of door warning lights by either crewmember immediately after the door closing sounds.

At 15:34:18, there was a sound of an engine increasing, similar to an engine starting. No mention of a "Before Start" checklist was noted. At 15:35:42, a sound similar to a second engine start was noted. At 15:36:22, the "After Start" checklist was called for. At 15:37:40, the "Taxi" checklist was called for. At 15:43:06, the flight was issued takeoff clearance. At no point during the ground operations through the takeoff sequence were the doors, door warning lights, or master caution system mentioned. During the "Before Takeoff" checklist, the co-pilot mentioned the annunciator; however, the pilot did not respond with "Recall" as is listed in the checklist item.

For additional information on the CVR and its audio recording and transcript, refer to the Cockpit Voice Recorder Group Chairman's Factual report, located in the public docket for this accident investigation.

The FDR was a Loral/Fairchild F1000, serial number 00633. The FDR contained about 174.4 hours of data. The recorder was in good condition and the data were extracted normally from the recorder. A review of the data revealed that the vertical and horizontal acceleration parameters were not working.

The FDR data indicated the aircraft took off on a magnetic heading of about 92 degrees. During the entire flight, the aircraft commenced mostly left turns. At about 130 seconds after takeoff, the aircraft reached a maximum pressure altitude of 3,033 feet before beginning its descent. About 6.5 minutes later, the aircraft landed at a magnetic heading of about 95 degrees. For additional information on the FDR and its data, refer to the Flight Data Recorder Specialist's Factual Report, located in the public docket for this accident investigation.

Integrity checks were performed on the main passenger door warning system and the aircraft master caution system. All lights associated with the door warning system were checked and illuminated when tested with the cockpit light test switch. No anomalies were found with the master caution light system, the "PASS DR READY" (passenger door ready) green light, or the "PASS DR UNLKD" (passenger door unlocked) amber light. An anomaly was found with the "PASS DR NOT RDY" (passenger door not ready) amber light. The light's designated ground was not available and the light would not illuminate when its circuitry was tested from the door interface. The PASS DR NOT RDY light illuminates only when the door T-handle is not stowed. According to the manufacturer, this anomaly would not affect the operation of the PASS DR READY (green) light as the PASS DR READY (green) light is an independent circuit.

The three sets of splices from the cabin door warning system were examined at the NTSB Materials Laboratory. Each submitted splice had wiring installed on only one side of the splice. Each splice was x-rayed to determine if wiring at some point was present on both sides of the splice. There was no evidence of marks, scratches or any other damage consistent with a wire having been installed and then pulled out. In addition, there were no remains of wiring present in the open end.

The integrity of the remaining door wiring harness found dangling from the airframe could not be verified because it was compromised (severed) when the main passenger door separated from the aircraft.

The pushrod, connecting the upper latch cams and lower latch cams, was sent to the NTSB Materials Laboratory for failure analysis. The rod was bent approximately 45° at the center and had fractured at one of the threaded ends. The pushrod also showed two dents approximately 3 inches from the opposite and intact end of the rod assembly. The threaded bolt showed compressed thread crests on one side and outstretched thread valleys on the other side. The majority of the original threaded surfaces bore a layer of rust-colored oxidation. This surface oxidation was not present on any of the fracture surfaces. Examination of the fracture surface revealed dimple rupture, which is indicative of overstress. The cracked areas in the stretched thread valleys also displayed dimple rupture. No other indications of other failure modes, including corrosion leading to fracture, were found. The observed features are consistent with bending overstress of the pushrod.

On July 5, 2009, about 1256 eastern daylight time, a Cessna 400 (Columbia Aircraft Manufacturing LC41-550FG), N207JB, registered to and operated by an individual, crashed in a wooded area, in Huntington, West Virginia, during an instrument flight rules (IFR) flight from the Tri-State Airport (HTS), Huntington, West Virginia, to Kalamazoo / Battle Creek International Airport (AZO), Kalamazoo, Michigan. Instrument meteorological conditions prevailed at the time and an IFR flight plan was filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The pilot and passenger were killed, and the airplane was destroyed. The flight departed HTS at 1254.

Information obtained from family members and local authorities reveal that the pilot was on a return IFR flight to AZO, the pilot's home base. The pilot was in the HTS area visiting family members. The pilot filed an IFR flight plan the night before and obtained a weather briefing on the morning of the accident at about 1041. The flight plan was filed for one person onboard. The decision to add a passenger was made later that morning.

An airport representative stated that the pilot called at 1100 to have the airplane pulled out of the hanger and fueled. The pilot requested to have a total of 10 gallons of Avgas added to the tanks; 5 gallons in each wing fuel tank. At 1210, the pilot arrived to the ramp, paid for the fuel, and started his preflight inspection. The representative noted that the pilot's preflight was about 25 minutes in duration. The airplane was started and taxied out of the area with no discrepancies observed.

The pilot received his IFR clearance and contacted the ground controller for taxi instructions to runway 12. The tower controller cleared the pilot for takeoff with an instruction to turn right for a heading of 210 degrees. A witness working near the departure end of runway 12 stated he heard and observed the airplane's engine rev up before departing from runway 12. He "watched the plane ascend and noted no abnormal functions and watched him turn in the distant". Once airborne, the pilot was then told by the tower controller to contact departure.

Radar data provided by the HTS airport surveillance radar (ASR) showed the airplane climbing to an altitude of 1, 500 feet (ft) means sea level (msl) , before turning right. The pilot contacted the departure controller and advised he was at 1,900 and climbing to 4,000. The radar data showed the airplane continue to climb to 2, 200 ft msl. The controller advised the pilot he had radar contact and asked the pilot what was his on course heading. The pilot responded 337 degrees. The departure controller asked the pilot if he was in a right turn and the pilot confirmed that he was. The departure controller instructed the pilot to continue the right turn to the on course heading and to maintain 5,000 ft msl. The pilot never acknowledged those instructions. The highest radar contact indicated the airplane was at 2,300 ft msl. About that time the radar showed the airplane turned left and started to descend. The last radar contact indicated the airplane was at 2,200 ft msl. The airplane was lost from radar immediately after that. The wreckage was located in close proximity and to the east southeast of the last radar contact.

A witness sitting on the back porch of his residence heard what sounded like a single engine airplane flying low near his home. A few moments later, he heard a loud crash sound resembling metal hitting trees, immediately after, the sound of the flying airplane stopped. The witness heard no sound of engine failure or other obvious malfunctions prior to the cessation of engine noise. He traveled to the ridge top behind his home and did not see anything that represented a plane crash. He called 911 to report the occurrence. The HTS Aircraft Rescue and Fire Fighting immediately responded to the notifications and shortly there after located the wreckage 3.5 miles south of the airport.

The pilot, age 54, seated in the front left seat, held a private pilot certificate with ratings for airplane single engine land and instrument airplane. He was issued a Federal Aviation Administration (FAA) third-class medical certificate on May 19, 2008, with limitations of must wear corrective lenses. He had documented 575 total hours at that time. The pilot had documented in his pilot's flight logbook a total of 642 flight hours as of June 28, 2009. Of those hours, 39 hours were in actual instrument flight, 1.3 hours within the prior 30 days of the accident, and 118 hours were simulated instrument time. The pilot documented a total of 184 hours in the accident airplane.

The passenger, seated in the right front seat, held no FAA certificates.

The Cessna 400 (Columbia Aircraft Manufacturer LC41-550FG) was built in 2005 with serial number 41564. On June 7, 2006 the airplane was issued a standard airworthiness certificate and registered in the utility category. The four place, composite built, fixed landing gear airplane was power by a Teledyne Continental Motors, TSIO-550-C, 310 horse power engine, which was equipped with a three bladed, Hartzell, variable pitch, propeller. The airplane was equipped with a Garmin 1000 avionic system and had a two axis autopilot system. The architecture of the Garmin-1000 avionic suite consists of multiple line replaceable units (LRUs) that perform the various functions and are connected together to form the general cockpit display. The airplane was maintained in accordance with the manufacturer's recommended maintenance program. A review of the airplane's maintenance records revealed the airplane had an annual inspection on the airframe, propeller, and engine on March 9, 2009, at which time the airplane had accumulated a total of 583 hours. The airplane had maintenance performed on June 9, 2009, when airworthiness directive 2009-9-9, dated May 11, 2009, was complied with at which time the airplane had accumulated a total of 602 hours.

The closest official weather observation was at HTS, 3.5 miles north of the accident site. The HTS 1251, METAR was winds from 090 degrees at 4 knots; visibility, 10 statute miles; clouds overcast at 800 ft above ground level (agl); temperature 19 degrees Celsius (C); dew point 18 degrees C; altimeter 29.87 inches of mercury.

The National Weather Services (NWS) Surface Analysis Chart for 1100 on July 5, 2009, depicted a warm front south of the accident site with an extensive area of low clouds along and north of the frontal system associated with overrunning conditions. The Huntington station model depicted easterly winds at 5 knots, visibility restricted in mist, overcast skies, a temperature of 66° F, with a 2° dew point spread. The Weather Depiction Charts for 1200 depicted the Huntington area in an area of IFR conditions due to low overcast ceilings at 600 ft agl with visibility restricted in light rain and mist. The Radar Summary Chart for 1219 depicted a large area of precipitation extending along and north of the frontal system.

The HTS special report at 1322, wind variable at 6 knots, visibility 10 miles in light rain, ceiling overcast at 1,000 ft agl , temperature 20° C, dew point 18° C, altimeter 29.85 inches of mercury. Remarks: automated observation system, peak wind from 200° at 28 knots at 1321, ceiling 700 ft variable 1,400 ft agl, hourly precipitation less than 0.01 inches.

The wreckage was located in a heavily wooded area on a hill ridge side at an elevation of 850 ft msl, from the departing runway. The initial impact was with 50 ft tall trees. The second impact was with the ground at the top edge of the ridge. The airplane was in a left wing low and about 50 degrees nose down pitch attitude during the impact sequence. The energy path of the wreckage was on an approximate course of 60 degrees along the descending ridge side. The debris field fanned outward from the initial tree impact point to 440 ft in distant by 75 ft in width. The cockpit, fuselage, wings, control surfaces were fragmented. The vertical stabilizer and rudder were recognizable. The engine, metal firewall, and propeller were crushed together and compacted with soil and wood. It was located 228 ft from the initial tree impact point behind a damaged tree trunk from the impact. The propeller separated from the engine crankshaft. The three propeller blades were twisted from mid point toward the tips with nicks and gouges throughout the length. One of the blades was bent 90 degrees aft. Another blade was missing a tip section.

A post recovery examination of the wreckage conducted by the airplane's manufacturer representative with Safety Board oversight established flight control continuity. All separations were consistent with overstress separation. All flight control surfaces were recovered. The right main landing gear strut, backup altimeter, and the left aileron control (balance) weight, were not located. The left aileron control weight attaching point damage was consistent with overstress separation. The flap actuator was observed in the full up position (retracted). The fuel selector valve was on the left fuel tank. The engine, propeller, and three avionic components (two flight computers, and one attitude reference unit) from the Garmin 1000 system were retained by the Safety Board for further examination.

A teardown examination of the propeller and engine were conducted by their respective manufacturer with Safety Board oversight. The propeller incurred damaged consistent with impact while operating at high power. All three blades had multiple bends with significant twisting. The blade preload plates had multiple impact marks at different blade angles indicative of the blades had multiple strikes and were changing pitch during the crash sequence. There were no discrepancies noted that would preclude normal operation of the propeller. The examination of the engine revealed all damages were consistent with impact damage. The engine examination did not reveal any abnormalities that would have prevented normal operation and production of rated horsepower.

The Safety Board Vehicle Recorder Division obtained information from the manufacturer, the various Garmin 1000 LRU boxes do store fault codes in non-volatile memory within each separate unit. These fault codes typically get triggered when there is a sensed error within the various LRU functions. Recorded fault codes are typically not continuously recorded but are rather event driven whenever a fault is detected and are stored for assistance in troubleshooting problems by maintenance personnel. The 3 units were physically damaged as a result of the accident. The damage was such that the units were not able to be powered up. According to the manufacturer the units recovered are capable storing fault data in onboard memory devices. The manufacturer was contacted to obtain assistance in reading out the individual memory chips located within the various units. Due to the fact that the units could not be re-powered, the normal maintenance extraction of the fault codes could not be accomplished. The manufacturer was unwilling to provide the laboratory the necessary detailed programming data structure information necessary to decode the memory in order to recover the fault codes from the individual memory devices.

Digital audio transmissions from the radar approach facility and the local control facility were sent to the Safety Board Vehicle Recorder Division's Audio Laboratory for a noise spectrum analysis. The transmissions indicated evidence of the engine/propeller operating at approximately 2540 rpm and indicated no evidence of aural cockpit warnings.

According to FAA advisory circular (AC) 60-4A, "Pilot's Spatial Disorientation," spatial orientation in flight is difficult to achieve especially in instrument meteorological conditions. It makes reference to an effective perception, integration and interpretation of visual,

vestibular, and proprioceptive sensory information must be maintained. Any discrepancies between the person's sensory inputs will result in a sensory mismatch that can produce illusions and lead to the pilot's spatial disorientation. It may take as much as 35 seconds to establish full control after loss of visual reference by qualified pilots. The spatial disoriented pilot may place the aircraft in a dangerous attitude, which can lead to a rapid, uncontrollable, near-vertical, descent.

The Department of Health and Human Services, Chief Medical Examiner Office in Charleston, West Virginia, conducted a postmortem examination. The cause of death for the pilot and passenger was blunt force trauma.

The FAA Civil Aeromedical Institute (CAMI) conducted toxicology testing on specimens from the pilot and passenger. No ethanol was detected in the pilot's urine; ethanol was detected in the in the muscle and liver, and putrefaction was noted. No ethanol was detected in the passenger's heart; ethanol was detected in the liver, muscle, lung, and kidney, and putrefaction was noted.