Landing (descent or approach)

The pilot had worked a 10-hour shift the day of the accident and had been off duty about 2 hours when the chief pilot called him around midnight to transport a patient. The pilot accepted the flight and, about 2 hours later, was on an instrument approach to the airport to pick up the patient. While on the instrument approach, all of the anti-ice and deice systems were turned on. The pilot said that the deice boots seemed to be shedding the ice almost completely. He extended the flaps and lowered the landing gear to descend; he then added power, but the airspeed continued to decrease. The airplane continued to descend, and he raised the flaps and landing gear and applied full climb power. The airplane shuddered as it climbed, and the airspeed continued to decrease. The stall warning horn came on, and the pilot lowered the nose to increase the airspeed. The airplane descended until it impacted level, snow-covered terrain. The airplane was equipped with satellite tracking and engine and flight control monitoring. The minimum safe operating speed for the airplane in continuous icing conditions is 140 knots indicated airspeed. The airplane's IAS dropped below 140 knots 4 minutes prior to impact. During the last 1 minute of flight, the indicated airspeed varied from a high of 124.5 knots to a low of 64.6 knots, and the vertical speed varied from 1,965 feet per minute to -2,464 feet per minute. The last data recorded prior to the impact showed that the airplane was at an indicated airspeed of 68 knots, descending at 1,651 feet per minute, and the nose was pitched up at 20 degrees. The pilot did not indicate that there were any mechanical issues with the airplane. The chief pilot reported that pilots are on call for 14 consecutive 24-hour periods before receiving two weeks off. He said that the accident pilot had worked the previous day but that the pilot stated that he was rested enough to accept the mission. The chief pilot indicated he was aware that sleep cycles and circadian rhythms are disturbed by varied and prolonged activity. An NTSB study found that pilots with more than 12 hours of time since waking made significantly more procedural and tactical decision errors than pilots with less than 12 hours of time since waking. A 2000 FAA study found accidents to be more prevalent among pilots who had been on duty for more than 10 hours, and a study by the U.S. Naval Safety Center found that pilots who were on duty for more than 10 of the last 24 hours were more likely to be involved in pilot-at-fault accidents than pilots who had less duty time. The operator’s management stated that they do not prioritize patient transportation with regard to their medical condition but base their decision to transport on a request from medical staff and availability of a pilot and aircraft, and suitable weather. The morning of the accident, the patient subsequently took a commercial flight to another hospital to receive medical treatment for his non-critical injury/illness. Given the long duty day and the early morning departure time of the flight, it is likely the pilot experienced significant levels of fatigue that substantially degraded his ability to monitor the airplane during a dark night instrument flight in icing conditions. The NTSB has issued numerous recommendations to improve emergency medical services aviation operations. One safety recommendation (A-06-13) addresses the importance of conducting a thorough risk assessment before accepting a flight. The safety recommendation asked the Federal Aviation Administration to "require all emergency medical services (EMS) operators to develop and implement flight risk evaluation programs that include training all employees involved in the operation, procedures that support the systematic evaluation of flight risks, and consultation with others trained in EMS flight operations if the risks reach a predefined level." Had such a thorough risk assessment been performed, the decision to launch a fatigued pilot into icing conditions late at night may have been different or additional precautions may have been taken to alleviate the risk. The NTSB is also concerned that the pressure to conduct EMS operations safely and quickly in various environmental conditions (for example, in inclement weather and at night) increases the risk of accidents when compared to other types of patient transport methods, including ground ambulances or commercial flights. However, guidelines vary greatly for determining the mode of and need for transportation. Thus, the NTSB recommended, in safety recommendation A-09-103, that the Federal Interagency Committee on Emergency Medical Services (FICEMS) "develop national guidelines for the selection of appropriate emergency transportation modes for urgent care." The most recent correspondence from FICEMS indicated that the guidelines are close to being finalized and distributed to members. Such guidance will help hospitals and physicians assess the appropriate mode of transport for patients.

On 7 May 2011, an Xi ’An MA60 aircraft, registered PK-MZK was being operated by PT. Merpati Nusantara Airline as a scheduled passenger flight MZ 8968, from Domine Eduard Osok Airport, Sorong, Papua Barat to Utarom Airport (WASK), Kaimana1, Papua Barat. The accident flight was part of series of flight scheduled for the crew. The aircraft departed from Sorong at 0345 UTC2 and with estimated arrival time in Kaimana at 0454 UTC. In this flight, the Second in Command (SIC) was as Pilot Flying (PF) and the Pilot in Command (PIC) as Pilot Monitoring (PM). On board the flight were 2 pilots, 2 flight attendants, 2 engineers and 19 passengers consisting of 16 adults, 1 child and 2 infants. The flight from Sorong was planned under the Instrument Flight Rules (IFR)3. The destination, Kaimana, had no published instrument approach procedure. Terminal area operations, including approach and landing, were required to be conducted under the Visual Flight Rules (VFR). At about 0425 UTC, after passing waypoint JOLAM the crew of MZ 8968 contacted Kaimana Radio and informed that the weather at Kaimana was raining, horizontal visibility of 3 to 8 kilometers, cloud Cumulonimbus broken at 1500 feet, south westerly wind at a speed of 3 knots, and ground temperature 29°C. The last communication with the crew of MZ 8968 occurred at about 0450 UTC. The flight crew asked whether there were any changes in ground visibility and the AFIS officer informed them that the ground visibility remained at 2 kilometer. The visual flight rules requires a visibility of minimum 5 km and cloud base higher than 1500 feet. The evidence indicates that during the final segment of the flight, both crew member were looking outside the aircraft to sight the runway. During this period the flight path of the aircraft varied between 376 to 585 feet and the bank angle increased from 11 to 38 degree to the left. The rate of descent then increased significantly up to about 3000 feet per minute and finally the aircraft impacted into the sea. The accident site was about 800 meters south west of the beginning of runway 01 or 550 meters from the coastline. Most of the wreckage were submerged in the shallow sea between 7 down to 15 meter deep. All 25 occupants were fatally injured. The aircraft was destroyed and submerged into the sea.

Shortly after takeoff from Loreto Airport, the crew encountered technical problems and elected to return. On final approach over the Gulf of California, in a gear up configuration, the aircraft struck the water surface and came to rest into the sea close to the shore, few dozen metres short of runway 34 threshold. Both pilots escaped uninjured while the aircraft was damaged beyond repair.

Following an uneventful flight from Dniepropetrovsk, the copilot started the approach to Moscow-Sheremetyevo Airport runway 25R with the flaps down at 22°. After touchdown, he started the braking procedure but the aircraft failed to decelerate as expected. The emergency braking systems were activated without any noticeable effect. Approaching the end of the runway at a speed of 70 knots, the copilot turn to the right in an attempt to veer off runway. The airplane ground looped then contacted a grassy area and lost its undercarriage before coming to rest. All 34 occupants escaped uninjured while the aircraft was damaged beyond repair.

The twin engine aircraft departed Robinson Crusoe Island on a cargo flight to Valparaiso, carrying one passenger, one pilot and a load consisting of 1,000 lbs of lobsters. Upon landing at Valparaiso Airport in good weather conditions, the airplane went out of control, veered off runway, crossed a road and came to rest in a wooded area located along the highway. The aircraft was damaged beyond repair and both occupants escaped with minor injuries.

Following an uneventful flight from Bridgetown-Grantley Adams Airport, the pilot landed at Castries-George F. L. Charles (Vigie) Airport. Upon touchdown, the left main gear collapsed. The aircraft veered off runway and came to rest against a fence. The pilot was uninjured and the aircraft was damaged beyond repair.

The multi-engine airplane was being repositioned to its base airport, and the pilot had requested to change the destination, but gave no reason for the destination change. Radar data indicated that the airplane entered the left downwind leg of the traffic pattern, flew at pattern attitude, and then performed a right approximate 250-degree turn to enter the final leg of the approach. During the final leg of the approach, the airplane crashed short of the runway into a house located in a residential neighborhood near the airport. According to the airplane's pilot operating handbook, the minimum multi-engine approach speed was 95 knots indicated airspeed (KIAS), and the minimum controllable airspeed was 82 KIAS. According to radar data, the airplane's ground speed was about 69 knots with the probability of a direct crosswind. Post accident examination of the propellers indicated that both propellers were turning at a low power setting at impact. During a controlled test run of the right engine, a partial power loss was noted. After examination of the throttle and control assembly, two o-rings within the assembly were found to be damaged. The o-rings were replaced with comparable o-rings and the assembly was reinstalled. During the subsequent test run, the engine operated smoothly with no noted anomalies. Examination of the o-rings revealed that the damage was consistent with the o-rings being pinched between the corner of the top o-ring groove and the fuel inlet surface during installation. It is probable that the right engine had a partial loss of engine power while on final approach to the runway due to the damaged o-ring and that the pilot retarded the engine power to prevent the airplane from rolling to the right. The investigation found no mechanical malfunction of the left engine that would have prevented the airplane from maintaining the published airspeed.

On approach to West Palm Beach Airport, the crew encountered technical problems with the undercarriage that could not be lowered. The crew decided to return to his base in Fort Lauderdale. On final, the crew was again unable to lower the gear so the decision was taken to complete a wheels-up landing. The airplane landed on its belly on runway 08 then slid for few dozen metres before coming to rest. The occupants escaped uninjured and the aircraft was damaged beyond repair.

The pilot reported that he performed a stabilized visual approach with a right crosswind. The airplane touched down on the centerline and subsequently drifted to the right. The pilot overcorrected for the drift and the airplane veered hard to the left. The airplane continued off the left side of the runway and skidded to a complete stop. The right main landing gear collapsed and the right wingtip hit the ground, which resulted in substantial damage to the fuselage and wing. A postaccident inspection of the airplane revealed no preimpact anomalies. The pilot additionally reported that there was no mechanical malfunction or failure.

On final approach to Kinshasa-N'Djili Airport, the crew encountered very poor weather conditions and decided to make a go around. After a climb process of 12 seconds, the aircraft nosed down and at a speed of 180 knots, hit the ground 170 meters to the left of the displaced threshold of runway 24. The aircraft slid for 400 meters before coming to rest in flames upside down. Three passengers were seriously injured and evacuated but of them died from their injuries few hours later. Finally, only one passenger survived the accident. Aircraft was performing a special flight from Kisangani to Kinshasa on behalf of the United Nations Organization Stabilization Mission in the Democratic Republic of the Congo (MONUSCO). The only survivor reported that the aircraft suddenly plunged into the earth while on final approach. At the time of the accident, weather conditions were marginal with storm activity, heavy rain showers, scattered at 2,200 feet and cumulonimbus at 1,500 feet.