Beechcraft 1900C

Aeropanamericano

The accident flight was a repositioning flight being operated by two airline transport pilots, and it was the multiengine turboprop airplane's first flight after an aviation maintenance technician (AMT) had replaced the left engine propeller with an overhauled propeller. The AMT subsequently performed an engine run, which included verifying correct power settings and corresponding blade angles. A review of flight data recorder (FDR) data revealed that, about 2 seconds after rotation, the left engine propeller rpm decreased to 60 percent, and the left engine torque increased off-scale (beyond 5,000 ft lbs), which is consistent with the left propeller traveling to the feathered position and the engine torque increasing in an attempt to maintain propeller rpm. About 30 seconds later, the flight crew shut down the left engine and attempted to return to the departure airport. Postaccident examination of the rudder trim actuator revealed that the rudder trim was at its full-right limit, which would have occurred to counteract the left engine drag before its shutdown. Based on this evidence, it is likely that the flight crew did not readjust the trim when the drag was alleviated, which resulted in the airplane being operated in a crosscontrolled attitude for about 50 seconds with a left bank and full-right rudder trim. Although the airplane should have been able to climb about 500 ft per minute with one engine operating, it slowed and descended from 300 ft in the cross-controlled attitude until it stalled, as indicated by a stall warning recorded by the cockpit voice recorder, and subsequently impacted terrain. Examination of the wreckage, including teardown examination of the left engine and propeller, did not reveal any preimpact mechanical anomalies. Review of the airplane maintenance manual revealed instructions to check the propeller reversing linkage on the front end of the engine, which controlled the beta valve, for proper rigging during propeller installation. The manual also contained a warning that misadjustment of the beta valve can cause unplanned feathering of the propeller and result in a possible hazard to airplane operation and over torque damage to the engine; however, the beta valve rigging could not be verified postaccident due to impact damage. Additionally, the ground/flight idle solenoid energizes when weight becomes off wheels and further opens the beta valve, which could exacerbate an existing misrigged condition as soon as the airplane becomes airborne, which is when the airplane experienced the uncommanded propeller feathering. The FDR data were consistent with the flight crew not performing the Before Takeoff (Runup) checklist. One of the items on that checklist was a low-pitch solenoid test, which would have energized the solenoid and possibly driven the left propeller uncommanded to feather during ground operations rather than in flight. A similar test during the post maintenance engine-run would have had the same results.

Sahel Aviation Service

The aircraft was planned to fly from Lanseria airport (FALA) in Republic of South Africa to Bamako airport (GABS) in Mali with a stopover in Ondangwa airport (FYOA) in Namibia, São Tomé International airport (FPST) in São Tomé and Príncipe and Accra airport (DGAA) in Ghana, with a rough estimating time of approximately 15hrs flying, not including the ground time at airports of stopover. The aircraft had been in Lanseria airport (FALA) in Republic of South Africa (RSA) for maintenance check (including but not limited to engine work and interior refurbishing). Prior to the planned flight, the aircraft underwent flight check for 45 minutes after completed planned maintenance on Saturday, April 6th, flown by the Captain and another SAS company pilot. The aircraft departed FALA to FYOA for its first stop over whose flight time was 03:35h. The planned departure from FYOA was delayed due to trouble in starting the right engine. The aircraft took off at 1021hrs contrary to planned 0830hrs. For the second leg of the flight, the aircraft departed FYOA to FPST with filed flight plan of 05 hours and 20 minutes (flight time) having FYOA as alternate. Leaving the Namibian airspace the pilot only contacted Luanda ATC and São Tomé Tower as destination, and at no time did he contact Brazzaville or Libreville for any further clearance within Brazzaville FIR: It is important to emphasize that on that day, the west coast of Africa in the vicinity of Gulf of Guinea had widespread moderate to severe thunderstorm activity with lighting and heavy rain. When initiating descent to São Tomé from FL 200 to 4000 feet as instructed by São Tomé ATC, the pilot was advised that weather was gradually deteriorating at airport vicinity. At 1610hrs the pilot had last transmission with Control Tower informing them about his position which was 9 nm inbound to São Tomé VOR at 4000 feet and also informed the ATC that he was encountering heavy rain. Having lost contact with aircraft at 1613hrs, the São Tomé ATC tried several times to contact the airplane by VHF118.9, 127.5, 121.5 and HF 8903 without success. Facing this situation the ATC sent messages to FIRs of Brazzaville and Accra and Libreville Control as well, some airlines flying within São Tomean an adjacent airspace were contacted for any information but all responses were negative. A Search and Rescue operation started on 7 April 2013 the same day the accident occurred and was conducted on the sea and on the island; no trace of aircraft or its debris, pilot or any cargo were found. The search was terminated on 20 April at 1730hrs.

ACE Air Cargo

Aircraft was destroyed when it impacted rising terrain about 10 miles east of Aleknagik, Alaska. The airplane was operated as Flight 51, by Alaska Central Express, Inc., Anchorage, Alaska, as an on demand cargo flight under the provisions of 14 Code of Federal Regulations (CFR) Part 135. The airline transport certificated captain and the commercial certificated first officer sustained fatal injuries. Instrument meteorological conditions were reported in the area at the time of the accident, and the airplane was operating on an instrument flight rules (IFR) flight plan. The flight had originally departed Anchorage about 0544, and made a scheduled stop at King Salmon, Alaska, before continuing on to the next scheduled stop, Dillingham, Alaska. According to Federal Aviation Administration (FAA) personnel, as the airplane approached Dillingham, the flight crew requested the RNAV GPS 19 instrument approach to the Dillingham Airport about 0757 from controllers at the Anchorage Air Route Traffic Control Center (ARTCC). The ARTCC specialist on duty subsequently granted the request by issuing the clearance, with instructions to proceed direct to the Initial Approach Fix (IAF) to begin the approach, and to maintain an altitude of 2,000 feet or above. A short time later the flight crew requested to enter a holding pattern at the IAF so that they could contact the Flight Service Station (FSS) for a runway conditions report, and the ARTCC specialist granted that request. The ARTCC specialist then made several attempts to contact the aircraft, but was unsuccessful and subsequently lost radar track on the aircraft. When the airplane failed to arrive at the Dillingham Airport, ARTCC personnel initiated a radio search to see if the airplane had diverted to another airport. Unable to locate the airplane, the FAA issued an alert notice (ALNOT) at 0835. Search personnel from the Alaska State Troopers, Alaska Air National Guard, and the U.S. Coast Guard, along with several volunteer pilots, were dispatched to conduct an extensive search effort. Rescue personnel aboard an Air National Guard C-130 airplane tracked 406 MHz emergency locater transmitter (ELT) signal to an area of mountainous terrain about 20 miles north of Dillingham, but poor weather prohibited searchers from reaching the site until the next morning. Once the crew of a HH-60G helicopter from the Air National Guard's 210th Air Rescue Squadron, Anchorage, Alaska, reached the steep, snow and ice-covered site, they confirmed that both pilots sustained fatal injuries.

Bolivian Air Force - Fuerza Aérea Boliviana

The twin engine aircraft departed Uyuni-La Joya Andina Airport on a flight to La Paz, carrying four passengers and three crew members. On approach to El Alto Airport, the crew encountered an unexpected situation. The captain decided to attempt an emergency landing in an open field. Upon touchdown, the undercarriage were torn off and the aircraft slid for few dozen metres before coming to rest 6 km from the airport. All seven occupants escaped uninjured while the aircraft was damaged beyond repair.

Kaya Airlines

The flight from Nampula was uneventful until the approach to Maputo. Due to bad weather conditions at destination, the crew was vectored to a holding pattern. After two circuits, the captain decided to start the descent despite ATC informed him about very poor conditions. At this time, the visibility was reduced due to the night, heavy rain falls, thunderstorm activity with turbulences and lightnings. On final approach to runway 23, the aircraft was too low and impacted ground short of runway in a slight nose-up attitude. Upon impact, the aircraft broke in two and came to rest in a field. All 17 occupants escaped with minor injuries and the aircraft was destroyed.

JS Air

0C-1 aircraft Reg # AP-BJD was scheduled to fly chartered flight from Jinnah International Airport (JIAP), Karachi to Bhit Shah Oil Fields to convey 17 employees of M/s Eni company including one foreign national from Italy. The flight crew included two cockpit crew ie Captain and First Officer (FO), one JS (Air) ground crew (technician) and one Airport Security Force staff. The Mishap Aircraft (MA) took off from JIAP, Karachi at 02:04:31 UTC. The reported weather was fit for the conduct of ill-fated flight to Bhit Shah Oil Fields. After takeoff aircraft experienced Engine No 2 abnormal operation and cockpit crew decided to land back at JIAP Karachi after calling right hand downwind for runway 25R. While joining for right hand downwind for 25R the mishap aircraft could not sustain flight and crashed at a distance of around 1 nm from runway 07R beginning JIAP, Karachi. All souls (21) onboard got fatally injured as a result of aircraft ground impact and extensive post impact ground fire.

ACE Air Cargo

The crew departed on a commercial cargo flight during dark night, visual meteorological conditions on an instrument flight rules flight plan. The departure end of the runway is adjacent to an ocean bay, and wind gusts up to 26 knots were reported. Local residents north of the airport reported stronger wind, estimated between 50 and 60 knots. A fuel truck operator, who was familiar with the crew’s normal routine, reported that, before the airplane taxied to the runway, it remained on the ramp for 6 or 8 minutes with both engines operating, which he described as very unusual. There were no reports of radio communications with the flight crew after the airplane departed. The airplane crashed about 1 mile offshore, and the fragmented wreckage sank in ocean water. Because of the fragmented nature of the wreckage and ocean current, the complete wreckage was not recovered. The cockpit area forward of the wings was extensively fragmented, thus the validity of any postaccident cockpit and instrument findings was unreliable. Likewise, structural damage to the airframe precluded determining flight control continuity. Both propellers had witness marks consistent with operating under engine power and within their normal operating range. A postaccident examination of the engines and recovered components did not disclose any evidence of a mechanical malfunction. Due to the lack of mechanical deficiencies of the engines and propellers, and the extensive airframe fragmentation consistent with a high-speed water impact, it is likely that the crew had an in-flight loss of control of an unknown origin before impact.

Air Serv International

The aircraft departed Kinshasa on a humanitarian flight to Goma with intermediate stops in Mbandaka, Kisangani and Bukavu. While approaching Bukavu-Kamembe Airport, the crew encountered poor visibility due to bad weather conditions. At an altitude of about 10,800 feet, the aircraft struck the slope of Mt Kahuzi located some 15 km northwest of Bukavu. The wreckage was found a day later in a wooded area. All 17 occupants were killed, among them emissaries.

Alpine Air

About one minute after takeoff on a night Instrument Flight Rules (IFR) contract cargo flight, the tower controller advised the pilot that he was squawking the wrong transponder code. Although the pilot reset the transponder to the correct code, he was advised that he was still squawking the wrong code. He then realized that he had selected the wrong transponder, and then switched to the correct one. During the time the pilot was dealing with this issue, the airplane drifted about 30 degrees right of the assigned heading, but the pilot returned to the correct heading as he was contacting the departure controller. The departure controller cleared him to continue his climb and instructed him to turn left about 120 degrees, which he did. About 40 seconds after initiating his left turn of about 120 degrees, while climbing straight ahead through an altitude about 4,700 feet above ground level (AGL), the pilot was instructed to turn 20 degrees further left. Almost immediately thereafter, the airplane began turning to the right, and then suddenly entered a rapidly descending right turn. The airplane ultimately impacted the terrain in a nearly wings-level nose-down attitude of greater than 45 degrees. At the moment of impact the airplane was on a heading about 220 degrees to the right of the its last stabilized course. The investigation did not find any indication of an airframe, control system, or engine mechanical failure or malfunction that would have precluded normal flight, and no autopsy or toxicological information could be acquired due to the high amount of energy that was released when the airplane impacted the terrain. The determination of the initiating event that led to the uncontrolled descent into the terrain was not able to be determined.

Flex Air

Chartered by Southern Sudan Air Connection to Flex Air Kenya, the aircraft departed Wau on a special flight to Juba with an intermediate stop in Rumbek, carrying a delegation of the South Sudan Government. While approaching Rumbek, the crew reported engine problems and elected to make an emergency landing when the aircraft crashed in a field located 45 km northwest from Rumbek, bursting into flames. All 21 occupants were killed, among them Justin Yak, personal adviser of the President of South Sudan, Dominic Dim Deng, Ministry of Defense, and 17 military officers.