A Qatar Airways Boeing 777-300 bound for Doha struck a runway’s lighting system in Miami during takeoff earlier this week, causing “substantial” damage to the aircraft, a US government report has said.

Records show that the plane, whose registration number is A7-BAC, continued its 13.5 hour flight to Doha on Sept. 15 “without incident,” despite significant damage to its underside.

According to an initial report published by the US Federal Aviation Authority (FAA), the aircraft struck the Approach Lighting System, a series of masts located about 60m beyond the end of the runway.

A normal flight would expect to pass over the approach lights at an altitude of several hundred feet, but it appears in this instance that the aircraft’s underbelly was low enough to strike the masts, which are only around 6m off the ground.

A notice to airmen (NOTAM) published by the airport states that the approach lighting system on that runway is now out of action, and won’t be back in service for a month, suggesting that it is seriously damaged.

Shorter runway distance

It is understood that the Qatar Airways 777 entered the runway at intersection T1, which is located approximately a third of the way down the runway.

This reduced the available distance for take off to 2,600m, 1,368m less than the full runway length of 3,968m.

Each flight, pilots calculate the minimum runway length required for takeoff, which is influenced by a number of factors, including temperature, wind, air pressure and the airplane’s load.

On a Qatar Airways 777, the electronic flight bag (EFB) system generates the precise data required for takeoff with any given length of runway.

It is unclear why this system failed, but it is clear that the aircraft did become airborne substantially later than would have been expected under normal circumstances.

In a previous case in 2009, an Emirates A340 taking off from Melbourne struck runway approach lights, just clearing the 2.24m (7 ft) tall airport perimeter fence.

The Australian Transport Safety Bureau (ATSB) concluded at the time that the flight crew had understated the takeoff weight by 100 tonnes, leading the aircraft to take off with substantially less thrust than required.

The aircraft was seriously damaged in the incident, and the crew decided to jettison fuel and to return to the airport.

Continued flight

The FAA report notes that the Qatar Airways flight continued “without incident” to Doha, and the Aviation Herald reports that communication between the flight crew and air traffic control in Miami was “routine.”

It is not yet clear whether the flight crew were aware that their aircraft had hit the approach lights, or whether they knew that the aircraft had sustained damage in the incident.

However, though there were no injuries, the FAA’s decision to label the event an “accident” and to call the resulting damage “substantial” reflects the seriousness of the incident.

An accident in FAA terms is defined as:

“An occurrence…in which any person (either inside or outside the aircraft) suffers death or serious injury, or in which the aircraft receives substantial damage.”

Data from plane tracking app Flightradar suggests that the aircraft has been out of service since returning from Miami on Wednesday afternoon.

Weather data for Miami at the time of the departure – about an hour after sunset – states that visibility was good, with light winds and some rain in the surrounding area.

Qatar Airways has not yet responded to a request for comment.

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