Fly Jamaica Airways Flight OJ256
On 9 November 2018, Fly Jamaica Airways Flight OJ256, operated by a Boeing 757-200 (registration N524AT), experienced a loss of left hydraulic system pressure approximately ten minutes after departure from Cheddi Jagan International Airport, Guyana, while climbing through flight level 200. The crew discontinued the climb and returned to the departure airport. On touchdown, the right hydraulic system also failed, leaving the aircraft with severely reduced braking capability. Combined with a non-standard flap setting and a brake-pumping technique that depleted the limited emergency brake reserve, the aircraft could not stop within the remaining runway distance, departed the paved surface, and sustained major structural damage. Ten people were injured during the evacuation; one elderly passenger, struck by another passenger while leaving the escape slide, later died from her injuries on 18 November, nine days after the accident. The investigation, conducted by Guyana's Aircraft Accident & Incident Investigation Unit with assistance from Canada's Transportation Safety Board, identified a chain of technical faults, a non-standard landing configuration, and maintenance and organisational shortcomings as probable and contributing causes.
INITIAL HYDRAULIC ANOMALY IN CLIMB
Approximately ten minutes after takeoff, while climbing through flight level 200 about 75 nautical miles northwest of the airport, the flight crew observed low quantity and low pressure indications for the left hydraulic system. The crew completed the applicable checklist, isolated the left system, and elected to return to Cheddi Jagan International Airport. The Power Transfer Unit activated automatically to allow the right hydraulic system to support the left.
PRESSURE SWITCH FAILURE AND RIGHT SYSTEM OVERHEAT
A failed pressure switch in the hydraulic system contributed to the developing fault. The right hydraulic pump subsequently overheated and was shut down by the crew per checklist; it was not required to be restarted for the remainder of the flight, leaving the right hydraulic system without its normal source of pressure by the time the aircraft landed.
LOSS OF RIGHT HYDRAULIC PRESSURE AT TOUCHDOWN
The landing was briefed and configured with 20 degrees of flap rather than a full landing flap setting, and the crew planned for a fast landing with maximum manual braking. On touchdown, right hydraulic system pressure dropped to zero, a failure the flight data recorder shows occurred at that exact moment. With both hydraulic systems now failed, the crew had no alternate or reserve braking, no thrust reverser capability, and no nose wheel steering.
LANDING ROLL AND RUNWAY EXCURSION
The flight crew applied intermittent, 'pumping' brake pressure rather than the continuous, steady pressure specified for a total hydraulic failure, which bled off the main brake pressure that remained. An emergency brake source switch, which would have provided immediate braking even with both hydraulic systems failed, was available but not activated; it had not been part of the crew's briefing for this phase of flight and was not required by the applicable checklist. The 20-degree flap setting, combined with the loss of braking, increased the landing speed and roll distance. The aircraft could not stop within the available runway, departed the paved surface into soft ground, and came to rest beyond the runway end with major structural damage.
Investigation Findings
- Loss of hydraulic fluid and failure of a pressure switch led to progressive failure of both hydraulic systems, first the left and subsequently the right, affecting spoiler deployment, thrust reversers and main brake effectiveness.
- The flight crew lost main braking after applying intermittent ('pumping') brake pressure, which bled off the remaining brake pressure, and did not activate the available emergency brake source that could have stopped the aircraft.
- The landing was configured with 20 degrees of flap rather than a full landing flap setting, resulting in a higher landing speed and roll distance.
- The investigation identified maintenance deficiencies and inadequate maintenance actions on the hydraulic system, including a leaking system that flight data recorder readings showed as a recurring trend over the six flights preceding the accident.
- Weaknesses in the airline's maintenance quality assurance and quality control, and management bypassing recommendations from its own Director of Maintenance and Quality Assurance Manager, were identified as having contributed to unresolved hydraulic system issues.
- Soft ground and loose sand in the runway overrun area contributed to the extent of damage sustained during the excursion.
- Ten people were injured during the evacuation; one elderly passenger, struck by another passenger while leaving the escape slide, died nine days after the accident from her injuries.
Engineering Lessons
- A single fault in a shared component such as a hydraulic pressure switch or Power Transfer Unit can propagate into a second, nominally independent hydraulic system — redundancy assumptions should account for such shared failure paths.
- Flight data recorder trends showing recurring hydraulic anomalies across multiple prior flights are an early warning that warrants investigation before the condition becomes a total system failure, not just a log entry to monitor.
- Emergency brake sources that fall outside a checklist's default flow for a given phase of flight still need to be briefed and trained for, since crews under pressure will default to familiar techniques such as pumping rather than holding steady pressure.
- Non-standard landing configurations selected for an abnormal situation, such as a reduced flap setting, should be weighed against their effect on landing speed and stopping distance, not only against go-around margins.
- Maintenance quality assurance and organisational safety culture are as consequential to flight safety as the physical repair of individual components; bypassing internal maintenance and QA recommendations removes a key safety barrier.
Official Sources
- Guyana Aircraft Accident & Incident Investigation Unit — Final Report AAIIU: 3/1/22/3
- Canada Transportation Safety Board (assisting investigation, ref. DCA19RA025 for NTSB)
- Aviation Herald — accident report summarising the GCAA final report's probable cause and contributing factors