CVLP, en-route, east of Miami Opa Locka USA, 2019
CVLP, en-route, east of Miami Opa Locka USA, 2019
On 8 February 2019, a Convair C131 climbing out of Nassau experienced a right engine propeller control malfunction. The Captain was able to stabilise power and continued the flight to Miami. As descent began, the same engine malfunctioned and was shut down but the left engine then also malfunctioned and, after an emergency declaration, a mishandled ditching followed. This wrecked the aircraft and only the First Officer survived, seriously injured. The Investigation noted that related engine malfunction on the outbound flight had not been recorded or investigated. No wreckage recovery was attempted so engine failure causes were not determined.
Description
On 8 February 2019, a General Dynamics Convair C131 Freighter (N145GT) being operated by Conquest Air on a cargo flight from Nassau to Miami Opa Locka experienced a right engine control malfunction passing 4000 feet on departure from Nassau but after engine power was ‘stabilised’, the intended overwater flight was then continued in day VMC. Subsequently, both engines successively malfunctioned and an emergency declaration and ditching attempt followed which destroyed the aircraft and resulted in the death of one pilot and serious injury to the other. Most of the wreckage sank and was not recovered but the left wing was later washed ashore.
The left wing of the aircraft as washed ashore. [Reproduced from the Official Report]
Investigation
An Investigation was carried out by the NTSB. The accident aircraft was operating under an FAA Part 135 AOC and configured for freight operations.
It was noted that the 68 year-old Captain had recorded a total of 23,000 hours total experience which included 725 hours on type. He had previously held type ratings on the Boeing 727 and Boeing 737 and had recorded 21,000 of his total 23,000 hours as in command. The 28 year-old First Officer had a total of 650 hours flying experience which included 305 hours on type, all of the latter obtained on the accident aircraft.
It was established that the aircraft had been on an out-and-back trip from Miami Opa Locka to Nassau. According to the First Officer, the pre-flight inspection, engine start, taxi, and engine run-up prior to the outbound flight were normal and about 900 gallons of fuel was on board. He stated that the flight itself, during which he had been PM, had been normal until he attempted to adjust the left engine propeller control to match the cruise speed when there was no indicated change and 2,400 rpm remained. After he had unsuccessfully tried to reset the left propeller control CB, the Captain had been able to stabilise power on both engines and the rest of the flight was without further event.
On arrival, the Captain asked the First Officer to send a text message to Company Maintenance Control, but when the message did not transmit the Captain had told him “not to worry and indicated that, if they were unable to reset the propeller control on the ground during the engine run-up, then they would shut down the airplane and call maintenance”.
As they prepared for the departure from Nassau, the First Officer stated that engine start had been normal, both propellers had been cycled and it had been possible to reset the left engine propeller control, so the flight had departed with the First Officer as PF. Initially, all had been normal, but climbing through 4,000 feet, “the left engine propeller control had stopped working, and the power was again stuck at 2,400 rpm”. After trying to adjust the propeller control and inadvertently increasing the setting to 2,700 rpm, the Captain had taken over as PF and again “stabilised the power on both engines”. He had then levelled the aircraft at 4,500 feet, cancelled the IFR flight plan and announced his intention to fly VFR direct to Miami (which was about 160 nm to the west northwest of Nassau) despite the First Officer suggesting that they turn back to Nassau. The First Officer said that he had not wanted to further challenge the Captain's decision to continue the flight given his much greater experience.
The flight continued without further event until the beginning of the descent into Miami when “the right engine began to surge and lose power”. The Captain had responded by selecting both fuel boost pumps on and attempting to stabilise the malfunctioning engine using the mixture control and throttle but that it had “begun to backfire and shake violently with variations in the Brake Mean Effective Pressure (BMEP), fuel pressure, fuel flow indications, rpm and manifold pressure”. The crew had then run the engine failure emergency checklist which included feathering the right propeller and selecting the mixture control to cutoff. The First Officer stated that “shortly afterwards” the left engine began to behave similarly and whilst the Captain unsuccessfully tried to control the engine, he had, as instructed by the Captain, declared an emergency.
Following the Captain’s attempts to manoeuvre the aircraft for ditching, it had hit the water "violently" causing the First Officer to strike his head on the instrument panel. He stated that having released his harness, he saw the Captain “slumped over in his seat and unresponsive”. He had tried to lift him out of his seat but was unable to do so and with the water level in the flight deck chest high, he realised that he needed to get out of the aircraft himself. He reported that after kicking open the flight deck door, he could see that “the tail had separated from the empennage (and) had grabbed the life raft and exited from the tail of the airplane". He was subsequently rescued by a Coast Guard helicopter.
It was established that the accident aircraft was 64 years old and the airframe total time was 12,701 hours at the time of the accident. It was powered by two Pratt & Whitney R-2800CB3 radial engines and two Hamilton Sunstrand 43E60-377 propellers that were being maintained under an FAA-approved aircraft inspection programme. The most recent inspection under this regime was found to have been on the day before the accident at which time the left engine was at 1,943 hours and the right engine was at “about” 417 hours.
Given the decision not to attempt to locate and recover the wreckage, it was not possible to determine the cause of the malfunctioning engines.
The Investigation determined that the Probable Cause of the accident was "the Captain's decision to continue with the flight with a malfunctioning left engine propeller control and the subsequent loss of engine power on both engines for undetermined reasons, which resulted in ditching into the ocean”.
A Contributory Factor to the accident was also identified as "the First Officer's failure to challenge the Captain's decision to continue with the flight”.
The Final Report was administratively ‘published’ 8 April 2020 and subsequently open-access published on 20 April 2020. No Safety Recommendations were made.