How the Louisville Cargo Plane Accident Developed and Potential Might Have Caused It

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

Aircraft specialists suggest the plane crashed after a single engine malfunctioned and a second seemed compromised during take-off.

It is unclear why the aircraft failed, prompting a massive fireball to ignite after it couldn't become airborne from the airstrip. Footage showed flames were consuming a single wing of the aircraft while it was attempting to take off, potentially spreading across the aircraft and triggered the blast, or the jet could have caught fire after colliding with an object on the ground.

What's clear is that the 144,000 litres of jet fuel aboard the MD-11 jet needed for the flight likely escalated the blaze, which rapidly extended to several buildings past the airstrip and burned for hours.

How did it start?

The shipping giant operates from the Louisville air hub as a distribution hub for its global operations and its Flight 2976 was beginning of a 4,300 mile trip to Honolulu in Hawaii 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 344km/h.

But verified footage shows that when the plane reached this speed a fire had completely engulfed its port side and the aircraft failed to gain altitude before the enormous detonation.

Authorities activated a local safety directive to local residents and scrambled numerous fire crews to the scene.

The state's governor confirmed particulars seen in CCTV footage that depict the aircraft flying just metres off the ground before a intense light engulfed the plane. It is then observed crashing onto the ground as a massive fire explosion erupts around it about a minute after departure.

A verified clip recorded by motorists on a nearby highway displayed the fire rising into the air while later videos showed smoke pouring from the area.

Overhead photographs shown on local media depicted wreckage scattering across the airstrip and landing on the roofs of at least two local businesses.

Potential causes of the accident

Air traffic control communications examined are largely garbled and filled with static so no meaningful conversation can be discerned about the incident as it developed.

But analysts proposed that a dramatic failure of multiple engines may have been responsible for the tragedy.

The trijet cargo aircraft uses three powerplants. Two are installed under the wings, and a third is built into the rear section at the base of the vertical stabilizer.

Footage confirmed showed a fire consuming the port wing of the plane, which then leaned leftward as it attempted to gain lift and take-off.

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

Additional photographs taken after the crash showed a charred engine sitting on the grass next to the runway.

An experienced former aviator and aircraft safety specialist said that it was "extremely rare" for an engine to detach during operation.

He referenced the 1979 American Airlines Flight 191 tragedy, in which 273 individuals were fatally injured after the plane's engine detached as it departed from Chicago's major airport. Parts of the engine had been damaged when it was replaced on the plane, but the specialist stated it was premature to determine whether a similar fault led to the powerplant separation on the MD-11.

The specialist said the freight aircraft would have been able to fly with only two powerplants but the damage caused by the fire on the left wing was probably extensive enough it resulted in the plane's third engine to fail to produce power.

"Given the severe nature of the incident we cannot determine what other damage was caused when the engine came adrift," the expert commented.

Another aviation expert observed the footage appeared to show the remaining powerplant had been damaged because it expelled a burst of smoke. The issue could have occurred while it was struck by wreckage from the fire and the engine detaching.

"The tail-mounted powerplant that expelled a puff of smoke seems to shut down right after," the specialist stated. "That left only the starboard powerplant producing thrust, resulting in a severe power imbalance and leaving the aircraft unable to achieve altitude.

"Losing two engines during take-off leaves the aircraft with only a third of its power and minimal opportunity of maintaining flight, particularly under maximum take-off weight," the specialist continued.

Reasons for extensive destruction

Post-accident videos revealed a scene of complete chaos with multiple fires blazing across a extensive area of the site and smoke rising upward.

The plane, which was 34 years old and had been operated for passenger travel until 2006, had previously made one round trip from the Kentucky hub to the East Coast on Tuesday.

It has not been confirmed which goods was on board the Hawaii-bound aircraft, though authorities stated the aircraft didn't contain anything that would pose an increased danger of environmental hazard.

"This was a long-haul cargo flight from Louisville to Honolulu, so the trijet was transporting a lot of jet fuel," a specialist said. "The substantial fuel quantity not only diminished capability but also accounts for the massive explosion observed post-accident."

Officials informed media that the plane was transporting 38,000 gallons of fuel for the long journey when it crashed. The fire was probably intensified on the surface because the aircraft slammed into a fuel processing facility next to the airport.

The expert said investigators will now focus on how the initial fire began, and "if wreckage hit the centre engine, and if previous repairs on the left engine played a role." The expert continued: "Atmospheric conditions were favorable, so environmental factors are improbable."

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