Ambulance

The pilot and two medical crew members departed on an air ambulance flight in night instrument meteorological conditions to pick up a patient. After departure, the local air traffic controller observed the airplane's primary radar target with an incorrect transponder code in a right turn and climbing through 4,400 ft mean sea level (msl), which was 800 ft above ground level (agl). The controller instructed the pilot to reset the transponder to the correct code, and the airplane leveled off between 4,400 ft and 4,600 ft msl for about 30 seconds. The controller then confirmed that the airplane was being tracked on radar with the correct transponder code; the airplane resumed its climb at a rate of about 6,000 ft per minute (fpm) to 6,000 ft msl. The pilot changed frequencies as instructed, then contacted departure control and reported "with you at 6,000 [ft msl]" and the departure controller radar-identified the airplane. About 1 minute later, the departure controller advised the pilot that he was no longer receiving the airplane's transponder; the pilot did not respond, and there were no further recorded transmissions from the pilot. Radar data showed the airplane descending rapidly at a rate that reached 17,000 fpm. Surveillance video from a nearby truck stop recorded lights from the airplane descending at an angle of about 45° followed by an explosion. The airplane impacted a pasture about 1.5 nautical miles south of the airport, and a post impact fire ensued. All major components of the airplane were located within the debris field. Ground scars at the accident site and damage to the airplane indicated that the airplane was in a steep, nose-low and wings-level attitude at the time of impact. The airplane's steep descent and its impact attitude are consistent with a loss of control. An airplane performance study based on radar data and simulations determined that, during the climb to 6,000 ft and about 37 seconds before impact, the airplane achieved a peak pitch angle of about 23°, after which the pitch angle decreased steadily to an estimated -42° at impact. As the pitch angle decreased, the roll angle increased steadily to the left, reaching an estimated -76° at impact. The performance study revealed that the airplane could fly the accident flight trajectory without experiencing an aerodynamic stall. The apparent pitch and roll angles, which represent the attitude a pilot would "feel" the airplane to be in based on his vestibular and kinesthetic perception of the components of the load factor vector in his own body coordinate system, were calculated. The apparent pitch angle ranged from 0° to 15° as the real pitch angle steadily decreased to -42°, and the apparent roll angle ranged from 0° to -4° as the real roll angle increased to -78°. This suggests that even when the airplane was in a steeply banked descent, conditions were present that could have produced a somatogravic illusion of level flight and resulted in spatial disorientation of the pilot. Analysis of the performance study and the airplane's flight track revealed that the pilot executed several non-standard actions during the departure to include: excessive pitch and roll angles, rapid climb, unexpected level-offs, and non-standard ATC communications. In addition to the non-standard actions, the pilot's limited recent flight experience in night IFR conditions, and moderate turbulence would have been conducive to the onset of spatial disorientation. The pilot's failure to set the correct transponder code before departure, his non-standard departure maneuvering, and his apparent confusion regarding his altitude indicate a mental state not at peak acuity, further increasing the chances of spatial disorientation. A post accident examination of the flight control system did not reveal evidence of any preimpact anomalies that would have prevented normal operation. The engine exhibited rotational signatures indicative of engine operation during impact, and an examination did not reveal any preimpact anomalies that would have precluded normal engine operation. The damage to the propeller hub and blades indicated that the propeller was operating under high power in the normal range of operation at time of impact. Review of recorded data recovered from airplane's attitude and heading reference unit did not reveal any faults with the airplane's attitude and heading reference system (AHRS) during the accident flight, and there were no maintenance logbook entries indicating any previous electronic attitude director indicator (EADI) or AHRS malfunctions. Therefore, it is unlikely that erroneous attitude information was displayed on the EADI that could have misled the pilot concerning the actual attitude of the airplane. A light bulb filament analysis of the airplane's central advisory display unit (CADU) revealed that the "autopilot disengage" caution indicator was likely illuminated at impact, and the "autopilot trim" warning indicator was likely not illuminated. A filament analysis of the autopilot mode controller revealed that the "autopilot," "yaw damper," and "altitude hold" indicators were likely not illuminated at impact. The status of the "trim" warning indicator on the autopilot mode controller could not be determined because the filaments of the indicator's bulbs were missing. However, since the CADU's "autopilot trim" warning indicator was likely not illuminated, the mode controller's "trim" warning indicator was also likely not illuminated at impact. Exemplar airplane testing revealed that the "autopilot disengage" caution indicator would only illuminate if the autopilot had been engaged and then disconnected. It would not illuminate if the autopilot was off without being previously engaged nor would it illuminate if the pilot attempted and failed to engage the autopilot by pressing the "autopilot" push button on the mode controller. Since the "autopilot disengage" caution indicator would remain illuminated for 30 seconds after the autopilot was disengaged and was likely illuminated at impact, it is likely that the autopilot had been engaged at some point during the flight and disengaged within 30 seconds of the impact; the pilot was reporting to ATC at 6,000 ft about 30 seconds before impact and then the rapid descent began. The airplane was not equipped with a recording device that would have recorded the operational status of the autopilot, and the investigation could not determine the precise times at which autopilot engagement and disengagement occurred. However, these times can be estimated as follows:
- The pilot likely engaged the autopilot after the airplane climbed through 1,000 ft agl about 46 seconds after takeoff, because this was the recommended minimum autopilot engagement altitude that he was taught.
- According to the airplane performance study, the airplane's acceleration exceeded the autopilot's limit load factor of +1.6 g about 9 seconds before impact. If it was engaged at this time, the autopilot would have automatically disengaged.
- The roll angle data from the performance study were consistent with engagement of the autopilot between two points:
1) about 31 seconds before impact, during climb, when the bank angle, which had stabilized for a few seconds, started to increase again and
2) about 9 seconds before impact, during descent, at which time the autopilot would have automatically disengaged. Since the autopilot would have reduced the bank angle as soon as it was engaged and there is no evidence of the bank angle reducing significantly between these two points, it is likely that the autopilot was engaged closer to the latter point than the former. Engagement of the autopilot shortly before the latter point would have left little time for the autopilot to reduce the bank angle before it would have disengaged automatically due to exceedance of the normal load factor limit. Therefore, it is likely that the pilot engaged the autopilot a few seconds before it automatically disconnected about 9 seconds before impact. The operator reported that the airplane had experienced repeated, unexpected, in-flight autopilot disconnects, and, two days before the accident, the chief pilot recorded a video of the autopilot disconnecting during a flight. Exemplar airplane testing and maintenance information revealed that, during the flight in which the video was recorded, the autopilot's pitch trim adapter likely experienced a momentary loss of power for undetermined reasons, which resulted in the sequence of events observed in the video. It is possible that the autopilot disconnected during the accident flight due to the pitch trim adapter experiencing a loss of power, which would have to have occurred between 30 and 9 seconds before impact. A post accident weather analysis revealed that the airplane was operating in an environment requiring instruments to navigate, but it could not be determined if the airplane was in cloud when the loss of control occurred. The sustained surface wind was from the north at 21 knots with gusts up to 28 knots, and moderate turbulence existed. The presence of the moderate turbulence could have contributed to the controllability of the airplane and the pilot's inability to recognize the airplane's attitude and the autopilot's operational status.

The single engine aircraft departed New Delhi at 0842LT on an ambulance flight to Bangkok with two pilots and three doctors on board. A refueling stop was completed at Calcutta Airport. At 1903LT, en route to Bangkok-Don Mueang Airport, the crew contacted ATC and requested permission to divert to Kamphaeng Saen Airport due to an emergency. The permission was granted and the crew initiated the descent when the aircraft disappeared from radar screens at 1916LT. The burned wreckage was found an hour and 30 minutes later, at 2048LT, in a wooded area located few km from runway 22L threshold. All five occupants were injured while the aircraft was destroyed. Few hours later, the copilot died from his injuries.

The pilot stated that the engine start and airplane power-up were normal for the air medical flight with two medical crewmembers. The engine ice vanes were lowered (as required for ground operations) and then were subsequently raised before takeoff. Takeoff and climbout were routine, and the pilot leveled off the airplane at the assigned cruise altitude. The air traffic controller informed the pilot of heavy showers near the destination airport, and the pilot "put the ice vanes down." The pilot indicated that, shortly afterward, the airplane experienced two "quick" electrical power fluctuations in which "everything went away and then came back," and "[s]econds later the entire [electrical] system failed." Due to the associated loss of navigation capability while operating in instrument meteorological conditions (IMC), the pilot set a general course for better weather conditions based on information from his preflight weather briefing. While the pilot attempted to find a suitable hole in the clouds to descend through under visual conditions, the left engine lost power. The pilot ultimately located a field through the cloud cover and executed a single-engine off-airport landing, which resulted in substantial damage to the right engine mount and firewall. A postaccident examination of the airplane and systems did not reveal any anomalies consistent with an in-flight electrical system malfunction. The three-position ignition and engine start/starter-only switches were in the ON position, and the engine anti-ice switches were in the ON position. When the airplane battery was initially checked during the examination, the voltmeter indicated 10.7 volts (normal voltage is 12 volts); the battery was charged and appeared to function normally thereafter. The loss of electrical power was likely initiated by the pilot inadvertently selecting the engine start switches instead of the engine anti-ice (ice vane) switches. This resulted in the starter/generators changing to starter operation and taking the generator function offline. Airplane electrical power was then being supplied solely by the battery, which caused it to deplete and led to a subsequent loss of electrical power to the airplane. A postaccident examination revealed that neither wing fuel tank contained any visible fuel. The left nacelle fuel tank did not contain any visible fuel, and the right nacelle fuel tank appeared to contain about 1 quart of fuel. The lack of fuel onboard at the time of the accident is consistent with a loss of engine power due to fuel exhaustion. This was a result of the extended flight time as the pilot attempted to exit instrument conditions after the loss of electrical power to locate a suitable airport. Further, the operator reported that 253 gallons (1,720 lbs) of fuel were on board at takeoff, and the accident flight duration was 3.65 hours. At maximum range power, the expected fuel consumption was about 406 lbs/hour, resulting in an endurance of about 4.2 hours. Thus, the pilot did not have the adequate fuel reserves required for flying in IMC. Both the pilot and medical crewmembers described a lack of communication and coordination among crewmembers as the emergency transpired. This resulted in multiple course adjustments that hindered the pilot's ability to locate visual meteorological conditions before the left engine fuel supply was exhausted.

On 13 December 2016, a Beech Aircraft Corporation B200, registered VH-MVL, conducted a medical services flight from Innamincka, South Australia (SA) to Moomba, SA. On board the aircraft were the pilot and two passengers. On arrival at Moomba at about 1250 Central Daylight-saving Time (CDT), the pilot configured the aircraft to join the circuit with flaps set to the approach setting and the propeller speed set at 1900 RPM. They positioned the aircraft at 150–160 kt airspeed to join the downwind leg of the circuit for runway 30, which is a right circuit. The pilot lowered the landing gear on the downwind circuit leg. They reduced power (set 600-700 foot-pounds torque on both engines) to start the final descent on late downwind abeam the runway 30 threshold, in accordance with their standard operating procedures. At about the turn point for the base leg of the circuit, the pilot observed the left engine fire warning activate. The pilot held the aircraft in the right base turn, but paused before conducting the engine fire checklist immediate actions in consideration of the fact that they were only a few minutes from landing and there were no secondary indications of an engine fire. After a momentary pause, the pilot decided to conduct the immediate actions. They retarded the left engine condition lever to the fuel shut-off position, paused again to consider if there was any other evidence of fire, then closed the firewall shutoff valve, activated the fire extinguisher and doubled the right engine power (about 1,400 foot-pounds torque). The pilot continued to fly the aircraft in a continuous turn for the base leg towards the final approach path, but noticed it was getting increasingly difficult to maintain the right turn. They checked the engine instruments and confirmed the left engine was shut down. They adjusted the aileron and rudder trim to assist controlling the aircraft in the right turn. The aircraft became more difficult to control as the right turn and descent continued and the pilot focused on maintaining bank angle, airspeed (fluctuating 100–115 kt) and rate of descent. Due to the pilot’s position in the left seat, they were initially unable to sight the runway when they started the right turn. The aircraft had flown through the extended runway centreline when the pilot sighted the runway to the right of the aircraft. The aircraft was low on the approach and the pilot realised that a sand dune between the aircraft and the runway was a potential obstacle. They increased the right engine power to climb power (2,230 foot-pounds torque) raised the landing gear and retracted the flap to reduce the rate of descent. The aircraft cleared the sand dune and the pilot lowered the landing gear and continued the approach to the runway from a position to the left of the runway centreline. The aircraft landed in the sand to the left of the runway threshold and after a short ground roll spun to the left and came to rest. There were no injuries and the aircraft was substantially damaged.

The airline transport pilot departed in the twin-engine, turbine-powered airplane on an air ambulance flight with two medical crew members and a patient on board in night visual meteorological conditions. According to a witness, during the initial climb, the airplane made a left turn of about 30° from the runway heading, then stopped climbing, made an abrupt left bank, and began to descend. The airplane impacted a parking lot and erupted into flames. In the 2 months before the accident, pilots had notified maintenance personnel three times that the left engine was not producing the same power as the right engine. In response, mechanics had replaced the left engine's bleed valve three times with the final replacement taking place three days before the accident. In addition, about 1 month before the accident, the left engine's fuel control unit was replaced during trouble shooting of an oil leak. Post accident examination revealed that the right engine and propeller displayed more pronounced rotational signatures than the left engine and propeller. This is consistent with the left engine not producing power or being at a low power setting at impact. Further, the abrupt left bank and descent observed by the witness are consistent with a loss of left engine power during initial climb. The extensive fire and impact damage to the airplane precluded determination of the reason for the loss of left engine power.

The crew was performing an ambulance flight from Yogyakarta-Adisujipto Airport to Jakarta-Halim Perdanakusuma Airport on behalf of the Indonesian Red Cross (Palang Merah Indonesia), carrying one patient, two doctors, two accompanists and three crew members. The approach was completed by night and marginal weather conditions. After touchdown on runway 24, the aircraft skidded on a wet runway. After a course of 1,300 metres, it veered to the right and departed the runway surface. While contacting soft ground, the right main gear was torn off while the left main gear partially collapsed. Then the aircraft bounced and impacted the ground several times, causing the left wing to be bent. Eventually, the right engine partially detached from the pylon. All eight occupants were rescued and the aircraft was damaged beyond repair. There was no fire.

About 13 minutes after takeoff for a medical transport flight, while climbing through about 14,900 ft mean sea level (msl), the pilot reported to air traffic control (ATC) that he was smelling smoke in the cockpit and would be returning to the originating airport. The flight was cleared to return with a descent at pilot's discretion to 9,000 ft msl. The pilot replied, "okay," and said that it looked like he was going to lose some power shortly. The pilot then stated that he had smoke in the cockpit, declared an emergency, and requested that ATC contact the fire department. About 1 minute 15 seconds after the initial report of smelling smoke, the pilot made the last radio transmission of the flight stating that he had three people on board. The wreckage was located about 9 hours later in an area of brush and heavily forested terrain. Portions of the burned and fragmented wreckage were scattered along a debris path that measured about 2,400 ft in length, which is consistent with an inflight breakup. The center fuselage and cockpit areas were largely intact and displayed no evidence of fire; however, there was an area of thermal damage to the forward fuselage consistent with an inflight fire. The thermal damage was primarily limited to the floor area between the two forward seats near the main bus tie circuit breaker panel and extended to the forward edge of the wing spar. All exposed surfaces were heavily sooted. Some localized melting and thermal-related tearing of the aluminum structure was present. The primer paint on the floor panels under the right aft corner of the pilot seat and the left aft corner of the co-pilot seat was discolored dark brown. An aluminum stringer in this location exhibited broomstrawing indicating that the stringer material was heated to near its melting point prior to impact. A single wire located in the area exhibited notching consistent with mechanical rubbing. The main bus tie circuit breakers were partially missing. The remaining breakers were heavily sooted on their aft ends, and one breaker was thermally discolored. Areas of charring were on the backside of the panel. Examination of the wiring in this area showed evidence of electrical arcing damage. Four hydraulic lines servicing the landing gear system were located in this area, and all the lines exhibited signs of thermal exposure with melting and missing sections of material. Six exemplar airplanes of the same make and model as the accident airplane were examined, and instances of unsafe conditions in which electrical lines and hydraulic lines in the area of the main bus tie circuit breaker panel were in direct contact were found on all six airplanes. Some of the wires in the exemplar airplanes showed chafing between hydraulic lines and the electrical wires, which, if left uncorrected, could have led to electrical arcing and subsequent fire. Based on the unsafe conditions found during examination of the exemplar airplanes and the thermal damage to the area near the main bus tie circuit breaker panel on the accident airplane, including broomstrawing of the aluminum structure, electrical arcing damage to the wiring, and melting of the hydraulic lines, it is likely that an electrical wire near the tie bus circuit breakers chafed on a hydraulic line and/or airplane structure, which resulted in arcing and a subsequent in-flight fire that was fed by the hydraulic fluid.

The commercial pilot was completing an instrument flight rules air taxi flight on a route that he had flown numerous times for the customer on board. Radar and voice communication data revealed that the airplane was vectored to the final approach course for the precision approach and was given a radio frequency change to the destination airport control tower frequency. The tower controller issued a landing clearance, which the pilot acknowledged; there were no further communications with the pilot. Weather conditions at the airport at the time of the accident included an overcast ceiling at 300 ft with 1 mile visibility in mist. The wreckage was located in densely-wooded terrain. Postaccident examination revealed no evidence of any mechanical malfunctions or anomalies that would have precluded normal operation. The wreckage path and evidence of engine power displayed by numerous cut tree branches was consistent with a controlled, wings-level descent with power. A radar performance study revealed that, as the airplane crossed the precision final approach fix 6.7 nautical miles (nm) from the runway threshold, the airplane was 800 ft above the glideslope. At the outer marker, 5.5 nm from the runway threshold, the airplane was 500 ft above the glideslope. When radar contact was lost 3.2 nm from the threshold, the airplane was about 250 ft above the glideslope. Although the airplane remained within the lateral limits of the approach localizer, its last two recorded radar returns would have correlated with a full downward deflection of the glideslope indicator in the cockpit, and therefore, an unstabilized approach. Further interpolation of radar data revealed that, during the last 2 minutes of the accident flight, the airplane's rate of descent increased from 400 ft per minute (fpm) to greater than 1,700 fpm, likely as a result of pilot inputs. During the final minute of the flight, the rate decreased briefly to 1,000 fpm before radar contact was lost. The company's standard operating procedures stated that, if a rate of descent greater than 1,000 fpm was encountered during an instrument approach, a missed approach should be performed. The airplane's relative position to the glideslope and its rapid changes in descent rate after crossing the outer marker suggest that the airplane never met the operator's stabilized approach criteria. Rather than executing a missed approach procedure as outlined in the company's operating procedures, the pilot chose to continue the unstabilized approach, which resulted in a descent into trees and terrain. It is unlikely that the pilot's well-controlled diabetes and effectively treated sleep apnea contributed to the circumstances of this accident. However, whether or not the pilot's multiple sclerosis contributed to this accident could not be determined.

The airplane departed Ouagadougou Airport at the end of the afternoon on an ambulance flight to Dakar-Léopold Sédar Senghor Airport with one patient, one doctor, two nurses and three crew members on board. After entering in contact with Dakar Control, the crew was cleared to FL340, an altitude that was confirmed by the crew at 1801LT. But the airplane continued and climbed to FL350. At 1812LT, the aircraft collided with a Boeing 737-8FB operated by Ceiba Intercontinental. Registered 3C-LLY, the B737 was operating the flight CEL071 Dakar - Cotonou - Malabo with 104 passengers and 8 crew members on board. Immediately after the collision, the BAe 125 entered an uncontrolled descent and crashed in the Atlantic Ocean about 111 km off Dakar. The pilot of the Boeing 737 informed ATC about a possible collision and continued to Malabo without further problem. Nevertheless, the top of the right winglet of the Boeing 737 was missing. SAR operations were suspended after a week and no trace of the BAe 125 nor the 7 occupants was ever found.

On 15 August 2015 at 2351Z a Cessna 441 aeroplane, with two crew and a paramedic on board took off from Eros Airport (FYWE) on a medical evacuation flight with their intended final destination Cape Town International Airport (FACT). The aircraft landed at Oranjemund (FYOG) to pick up a male patient and his daughter. At 0206Z the aircraft departed from FYOG on a mercy flight to FACT. At 0343Z the aircraft made the first contact with FACT area and the aircraft was put under radar control. At 0355Z, area control advised the crew that there was a complete radar failure. The aircraft was on a descent to 6500 ft when approach advised them to prepare for a VOR approach for runway 19. At 0429Z, while on approach for landing at FACT, all contact was lost with the aircraft. At approximately 0556Z the aircraft’s wreckage was located approximately 8 nm to the north of FACT. All five occupants on board were fatally injured and the aircraft was destroyed by impact and post impact fire. The investigation revealed the aircraft collided with terrain during instrument meteorological condition (IMC) conditions while on the VOR approach for Runway 19 at FACT. At the time the ILS was working, however the approach controller offered a VOR approach for separation with an outbound aircraft as the radar was unserviceable.