An investigation found that the pilots had ignored proximity warnings on the plane before it ditched into the lagoon.
Footage from a plane crash reveals the harrowing final moments in the cockpit before the aircraft plummeted into the water.
The video captured inside the cockpit was pivotal for the investigation of the crash, during which one person died and nine others sustained injuries.
In 2019, an investigation into the Air Niugini flight exposed the chilling footage.
The aircraft was attempting to land at Chuuk International Airport in Micronesia, Papua New Guinea, in September 2018.
A storm had obscured visibility of the runway, forcing the pilots to depend entirely on their instruments for landing.
However, the investigation discovered that the pilots, engrossed in their landing approach, overlooked a critical alert on the plane's console.
This alert was activated by the plane's proximity warning systems.
Consequently, the plane was urgently signaling to 'PULL UP'.
In the footage, just moments before the plane crashed into the Chuuk Lagoon, the co-pilot is heard urgently saying: "Too low! We're too low! We're too low!"
This occurred approximately 1,500ft short of the runway.
The video was recorded by the flight's engineer who was filming the plane's descent from about 3000ft as a personal hobby.
Following the crash, the investigation concluded: "The crew were fixated on the task of landing the aircraft and did not notice the visual PULL UP caution alert at the bottom of their PFD.
"Therefore, they (the crew) did not take any positive action to arrest the high rate of descent and avoid landing in the lagoon.
"In fact, neither of the pilots were aware of the rapidly unfolding unsafe situation."
One individual lost their life in the incident, and nine others were injured.
In the aftermath, a collection of small boats manned by locals and US navy divers quickly surrounded the downed plane to help rescue the passengers and crew from the water.
About 12 crew members and 34 passengers managed to evacuate the partially submerged aircraft after it ditched into the sea.
Reflecting on the incident, Chief Commissioner Hubert Namani remarked:
"Both pilots were fixated on cues associated with control inputs for the landing approach, and subsequently, were not situationally aware and did not recognise the developing significant unsafe condition of an increasingly unstable final approach."
He emphasized: "The importance of the imagery obtained from the video taken by the engineer in the cockpit jump seat cannot be understated.
"It provided clear pictures in real time of the cockpit environment and instruments."