Landing (descent or approach)

Aircraft was on a flight from Toronto-Lester B. Pearson International Airport to Toronto-Buttonville Municipal Airport, Ontario, with 2 pilots on board. Air traffic control cleared the aircraft for a contact approach to Runway 33. During the left turn on to final, the aircraft overshot the runway centerline. The pilot then compensated with a tight turn to the right to line up with the runway heading and touched down just beyond the threshold markings. Immediately after touchdown, the aircraft exited the runway to the right, and continued through the infield and the adjacent taxiway Bravo, striking a runway/taxiway identification sign, but avoiding aircraft that were parked on the apron. The aircraft came to a stop on the infield before Runway 21/03. The aircraft remained upright, and the landing gear did not collapse. The aircraft sustained substantial damage. There was no fire, and the flight crew was not injured. The Toronto-Buttonville tower controller observed the event as it progressed and immediately called for emergency vehicles from the nearby municipality. The accident occurred at 1506 Eastern Daylight Time.

According to the captain, while on approach to land, he distracted the crew by pointing out a boat dock. He said that after touchdown, he realized that the landing gear was not extended, and the airplane slid on its belly, sustaining substantial damage to the underside of the fuselage. He said that the crew did not hear the landing gear retracted warning horn, and the accident could have been prevented if he had not distracted the crew. The captain reported that there were no mechanical malfunctions with the airplane that would have precluded normal operation.

The crew departed Port Gentil on a cargo flight to Libreville on behalf of DHL Airways. On approach to Libreville-Léon Mba Airport, the captain informed ATC about hydraulic problems and initiated a go-around procedure. Shortly later, the aircraft stalled and crashed in the sea some 2,3 km southeast of the airport. All four occupants were rescued while the aircraft was damaged beyond repair. Due to the failure of the hydraulic system, the crew was unable to lower the gear.

The pilot indicated that, prior to the accident flight, the wing flaps had failed, but he decided to proceed with the flight contrary to the Airplane Flight Manual guidance. While conducting a no-flap approach to the airport, he decided that his airspeed was too fast to land, and he initiated a go-around. During the go-around, the airplane continued to descend, and the fuselage struck the runway. The pilot was able to complete the go-around, and realized that he had not extended the landing gear. He lowered the landing gear, and landed the airplane uneventfully. He elected to remain overnight at the airport due to fatigue. The next day, he decided to test fly the airplane. During the takeoff roll, the airplane had a severe vibration, and he aborted the takeoff. During a subsequent inspection, an aviation mechanic discovered that the center wing carry-through cracked when the belly skid pad deflected up into a stringer during the gear-up landing.

Following an uneventful flight, the flight crew briefed the arrival to the destination airport and set the calculated landing speeds. The captain and the first officer reported that during final approach, it felt like the airplane was “pushed up” as the wind shifted to a tailwind or updraft before landing near the runway number markings. Upon touchdown, the captain applied the brakes and thought that the initial braking was effective; however, he noticed the airplane was not slowing down. The captain applied maximum braking, and the airplane began to veer to the right; he was able to correct back to the runway centerline, but the airplane subsequently exited the departure end of the runway and traveled down a steep embankment. A pilot-rated passenger reported that throughout the approach to landing, he thought the airplane was high and thought that the excessive altitude continued through and into the base-to-final turn. He added that the bank angle of this turn seemed greater than 45 degrees. Recorded communication from the cockpit voice and data recorder (CVDR) revealed that during the approach to landing, the flight crew performed the landing checks, and the captain noted difficulty judging the approach. About 1 minute later, the recording revealed that the ground warning proximity system reported “five hundred” followed by a “sink rate, pull up” alert about 16 seconds later. Data from the CVDR revealed that about 23 seconds before weight-on-wheels was recorded, the airplane was at an indicated airspeed of about 124 knots and descending. The data showed that this approximate airspeed was maintained until about 3 seconds before weight-on-wheels. The recorded data further showed that the approach speed was set to 120 knots, and the landing reference speed (vREF) was set to 97 knots. Using the reported airplane configuration and the 3.5-knot headwind that was reported at the time of the approach and landing, calculations indicate that the vREF speed should have been about 101 knots indicated airspeed, which would have required a landing distance of about 3,112 feet. Utilizing the same airplane configuration and wind condition with the flight’s reported 124 knot indicated airspeed just before touchdown, the landing distance was calculated to be about 5,624 feet. The intended runway for landing was 5,132-feet long with a 1.9 percent downward slope gradient, and a 123-foot long overrun area. A postaccident examination of the airplane, including the braking system, revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The pilot misjudged the airplane’s speed during the final approach, which resulted in runway overrun.

According to the airplane's operator, the airplane was part of a flight of four airplanes that were taking an organized tour group of revenue passengers on a sightseeing tour of southern Utah. While operating in a high density altitude environment, the pilot was flying into an airport that had a 1,000-foot cliff about 400 feet from the end of the runway he was landing on. Because of the presence of the cliff, the Airguide Publications Airport Manual stated that all landings should be made on the runway that was headed toward the cliff and that all takeoffs should be made on the runway that was headed away from the cliff. The manual also stated that a go-around during landing was not possible. During his approach, the pilot encountered a variable wind and downdrafts. During the landing flare, the airplane dropped onto the runway hard and bounced back into the air. The pilot then immediately initiated a go-around and began a turn away from the runway heading. While in the turn, he was most likely unable to maintain sufficient airspeed, and the airplane entered a stall/mush condition and descended into the ground. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

The pilot reported that he flew an instrument approach and was clear of clouds about 650 feet above ground level when he proceeded visually to the airport. About 1/2 mile from the runway, he thought the airplane was too high, but a few seconds later the airplane felt like it had an excessive rate of descent. His attempts to arrest the rate of descent were unsuccessful, and the left main landing gear struck the ground about 120 feet prior to the runway threshold. The recorded data downloaded from the airplane's non-volatile memory showed that the airplane's airspeed varied from about 71 - 81 knots indicated airspeed (IAS) during the 10 seconds prior to ground impact. The data also indicated that there was about a 3 - 5 knot tailwind during the final landing approach. The airplane's stall speed with the airplane in the landing configuration with landing flaps was 64 knots IAS at maximum gross weight. The pilot reported that there was no mechanical malfunction or system failure of the airplane.

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.