2019 Laser Aéreo Douglas DC-3 crash

On 9 March 2019, a Douglas DC-3 operated by Latinoamericana de Servicios Aéreo (Laser Aéreo) crashed near San Carlos de Guaroa, Colombia. The plane was on a flight from Jorge Enrique González Torres Airport, San José del Guaviare to La Vanguardia Airport, Villavicencio. All 14 people on board were killed, including the mayor of Taraira. The crew were attempting to land at Villavicencio and had just declared an emergency.

Aircraft
The Aeronautica Civil reports that the aircraft, registered HK-2494, was built in 1945, for the United States Army Air Force (USAAF) as a Douglas TC-47B-DK (USAAF 44-76773 / MSN 16357 / 33105), and converted to a Douglas R4D-7 (USN Bureau Number 99826) for the United States Navy on 14 May 1945. Re-designated as a Douglas TC-47K in 1962, it was transferred to the University of Texas at Austin on 8 Oct 1971 with civil registration N87611.

Crash
As the aircraft was cruising, the left engine suffered a failure, which disabled the oil system in that engine. The crew then radioed in a mayday and diverted to La Rinconada, a plantation. While they were descending, the crew could not feather the engine which was required in an engine failure, thus they began to lose speed as the engine windmilled, creating drag. At 10:31 am local time, the crew made their final transmission stating they had the runway in sight. Ground witnesses in the area said they saw the aircraft doing several turns while descending. The aircraft then crashed in proximity to a road, coming to rest just over the road, on fire. Plantation workers rushed to help, but they found no survivors.

Investigation
On 12 March 2019 three days after the crash, the Colombian DGCA opened an investigation reporting that the aircraft at 10.15 a.m local time was approximately 109 km from Villavicencio when the pilots reported that the left hand engine was failed and that they were unable to feather the propeller of the left engine which would not permit their continuation to Villavicencio with only the right engine operative. Meanwhile, the tower controllers served various landing options, there were indications that the aircraft attempted to reach a runway at La Rincoñada (3.5658°N, -73.0814°W) that is about 65 km from the point where the engine failed. The aircraft was in a continuous descent, subsequently the pilots reported that they had in sight a landing facility between palm trees however they did not lower the landing gear. The radar contact was lost at 10:31 a.m. Seconds after last radio contact, the Emergency Locator Transmitter (ELT) was activated at 10:36 a.m. Workers on the plantation saw the plane make a few uncontrolled turns and going down prior to the crash. The workers also went to help find survivors but without result, all occupants were found dead.

On 17 March 2019 the Colombian DGCA released the preliminary report stating that the aircraft was trying to reach a runway at La Rinconada, that, as indicated on maps, is very close to the crash site. The aircraft was planned to fly at 8.500 feet according to visual flight rules. The aircraft was climbing to 8.100 feet about 30 nm from San Josè del Guaviare when the pilots reported that they were having a problem with an engine. The controller suggested a number of landing places nearby the airplane, the crew decided to land at Pista La Rinconada. The last radio contact was received at 10:35 a.m when the crew stated that they had the landing point in sight, at 10:36 a.m. the emergency locator transmitter was activated.

First findings made by the report said that the aircraft crashed into the ground at a high rate of descent at heading 266 degrees and at low speed. The airplane wreckage was scattered over an 800 squared meter area, all parts were found on the site area. The landing gear was retracted also the flaps were retracted. All flight controls were working. Both engines were found severely damaged, the left propeller was not feathered. The left side of the aircraft sustained substantial damage caused by the impact with terrain while the right side was almost without any damage. The left power lever was found working at 100% of power, the right power lever instead was working at 0% of power, at idle. The left propeller angle was set at 80% in forward position, the right propeller angle instead was set at 50% in back/reverse position. The GPS system on board the airplane was found undamaged but without containing any information about the accident flight.

On 3 January 2021 Grupo de Investigacion de Accidentes (GRIAA) released the final report stated that the probable causes were the following:


 * The loss of control during the flight as a result of loss of speed caused by the inability to feather the left engine propeller;
 * The malfunction of the lubrication system on the number-1 engine that was noticed for an oil leak in engine power system and propeller governor during the flight, despite were found discrepancies in the maintenance of the pressure line of propeller feathering system it was impossible to determined the cause why the oil leak was occurred;
 * Inadequate supervision in operations procedures by the operator causing poor standards in the decision making in case of critical failures event, like selecting an alternative airport or performing an emergency landing on open fields.

Other contributing factors are also found by the investigation that are the following:


 * Lack in maintenance procedures of the pressure lines of the propeller feathering system on number-1 engine;
 * Violation of effective and adequate maintenance program, which did not check actual conditions of the aircraft components. The investigation will be not be able to determine where and when the last 50 hours services of number-1 engine were checked because there were no entries reported of last service in the log book;
 * Ineffective safety program by the operator who did not detected any errors in the maintenance process and on the conduct and control of these operations.