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At least nine people lost their lives and 11 others were hurt after a UPS cargo plane went down during departure from a major air hub in Kentucky's largest city on Tuesday evening.

Aviation experts believe the aircraft went down after a single engine malfunctioned and a second seemed compromised while lifting off.

It is unclear why the aircraft failed, prompting a huge explosion to erupt after it failed to take-off from the runway. Video evidence revealed flames were consuming a single wing of the aircraft while it was attempting to take off, potentially spreading through the plane and triggered the blast, or the jet could have caught fire upon hitting ground-based obstacles.

What is apparent is that the 144,000 litres of fuel on board the trijet aircraft needed for the flight probably intensified the blaze, which rapidly extended to several buildings beyond the runway and burned for hours.

How did it start?

UPS operates from Louisville Muhammad Ali International Airport as a logistics center for its global operations and its Flight 2976 was beginning of a 4,300 mile journey to Hawaii's capital when the freight aircraft attempted to take off.

Data from flight monitoring services indicates the plane began to taxi along the 17R runway at around 5:15 PM local and attained a top speed of 214mph.

However, confirmed videos demonstrate that by the time the plane achieved this velocity a fire had completely engulfed its port side and the aircraft failed to gain altitude before the enormous detonation.

Authorities activated a shelter-in-place order to area inhabitants and dispatched hundreds of firefighters to the scene.

The state's governor confirmed details visible in security camera recordings that depict the aircraft flying just metres off the ground before a intense light engulfed the plane. It is then seen slamming into the ground as a massive fire explosion ignites surrounding it about a minute into its journey.

Authenticated footage taken by motorists on a nearby highway showed the fire rising into the air while subsequent recordings showed smoke billowing from the scene.

Aerial images broadcast by local media depicted debris showering the runway and landing on the tops of multiple nearby establishments.

Potential causes of the accident

Air traffic control communications examined are largely garbled and full of interference so no clear dialogue can be discerned about the crash as it unfolded.

But analysts suggested that a catastrophic malfunction of multiple engines may have been the cause of the tragedy.

The MD-11 transport plane employs three powerplants. Two are installed under the airfoils, and a third is positioned in the tail at the base of the vertical stabilizer.

Video verified revealed a blaze engulfing the port wing of the aircraft, which then tilted to the left as it tried to achieve altitude and become airborne.

Two experts independently suggested the left engine may have detached from the plane following a mechanical or structural failure.

Additional photographs captured post-accident displayed a charred engine sitting on the grass adjacent to the airstrip.

A retired airline pilot and aircraft safety specialist said that it was "extremely rare" for an powerplant to separate in flight.

The expert recalled the 1979 aviation disaster tragedy, in which 273 individuals were killed after the plane's engine detached as it departed from O'Hare International Airport. Parts of the engine had been compromised when it was installed on the aircraft, but the expert said it was premature to determine whether a similar fault caused the powerplant separation on the MD-11.

The expert explained the cargo plane would have been able to fly with just two engines but the damage resulting from the wing blaze was probably extensive enough it caused the aircraft's remaining engine to fail to produce power.

"With such a catastrophic event we cannot determine what other damage was caused when the engine came adrift," the expert commented.

A different aircraft specialist said the video evidence appeared to show the third engine had been damaged because it released smoke. The damage could have occurred while it was struck by wreckage from the blaze and the powerplant separation.

"The tail-mounted powerplant that expelled a puff of smoke appears to wind down almost immediately afterwards," the specialist stated. "This left just the starboard powerplant generating power, creating a significant thrust asymmetry and making the plane incapable to gain height.

"Failing two powerplants while departing results in only a fraction of its thrust and minimal opportunity of maintaining flight, particularly under full departure mass," the expert continued.

Reasons for extensive destruction

Footage from the aftermath revealed a scene of complete chaos with numerous blazes burning across a extensive area of the site and smoke billowing into the sky.

The aircraft, which was 34 years old and had been used as a passenger plane until 2006, had already completed one round trip from Louisville to Baltimore in Maryland on the same day.

Authorities haven't verified what cargo was on board the Hawaii-bound aircraft, though authorities stated the aircraft didn't contain anything that would create a heightened risk of environmental hazard.

"This involved extended freight transport from Kentucky to Hawaii, so the trijet was carrying a lot of jet fuel," a specialist said. "That heavy fuel load not only diminished capability but also explains the massive explosion seen after the crash."

Officials informed media that the plane was transporting 38,000 gallons of fuel for the long journey when it crashed. The blaze was likely amplified on the ground because the plane crashed into a fuel processing facility next to the airport.

A specialist indicated investigators will now focus on the origin of the blaze, and "whether debris struck the centre engine, and if previous repairs on the left engine played a role." The expert continued: "Atmospheric conditions were favorable, so weather-related causes are unlikely."

The National Transportation Safety Board has dispatched personnel to the site and will now lead the investigation into the causes of the crash, though this can take up to two years to finalize.