What Is A Rejected Takeoff And Why Do They Occur?

When reading about incidents in the aviation industry, one sometimes comes across the term ‘rejected takeoff.’ This appears,…

What Is A Rejected Takeoff And Why Do They Occur?

When reading about incidents in the aviation industry, one sometimes comes across the term ‘rejected takeoff.’ This appears, at face value, to be a fairly self-explanatory phrase, although there are several aspects to the process. Let’s take a look at what exactly it entails.

French bee A350-900
In a minority of cases, pilots will have to abort their departure. Photo: Vincenzo Pace | Simple Flying

What is a rejected takeoff?

The term ‘rejected takeoff’ refers to incidents in which an aircraft’s pilots elect to abort their departure before reaching a critical speed. This measurement is known as ‘V1,’ and refers to the maximum speed an aircraft can reach on its takeoff roll and still have sufficient space to stop before the end of the runway. This is often calculated before departure.

According to Skybrary, rejected takeoffs are typically categorized as either low-speed or high-speed. Manufacturers generally define the transition between these two categories as being somewhere between 80 and 100 knots. Manufacturers are also obliged to perform rejected takeoff tests on new aircraft, as Boeing did with its 777X in March 2020.

Boeing 777X
Boeing completed rejected takeoff tests on its upcoming 777X last year. Photo: Jay Singh – Simple Flying

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Reasons to abort a departure

Commercial aviation is an intensely safety-driven industry. As such, it is often better to be safe than sorry, and to take precautionary measures to stop a situation from escalating dangerously. This is why there are several reasons why a rejected takeoff might occur. Boeing states:

“A takeoff may be rejected for a variety of reasons, including engine failure, activation of the takeoff warning horn, direction from air traffic control (ATC), blown tires, or system warnings.”

Plane committed to takeoff V1 speed
Pilots can choose to reject a takeoff for several reasons. Photo: Getty Images

Nonetheless, in many cases, issues during the takeoff roll can be overcome, rendering an aborted departure unnecessary. Indeed, the US aircraft manufacturer adds that:

The large number of takeoffs that continue successfully with indications of airplane system problems, such as master caution lights or blown tires, are rarely reported outside the airline’s own information system.(…) In fact, in about 55 percent of [rejected takeoffs], the result might have been an uneventful landing if the takeoff had been continued.”

Boeing 747 Heathrow Sunset Getty
Aircraft can sometimes continue their journey and land safely despite issues arising during takeoff.         Photo: Getty Images

Recent incidents

While rejected takeoffs are rare occurrences, they still happen more often than one might think. Indeed, Simple Flying has reported on several of these incidents in 2021 alone. For example, this January saw a LATAM Brazil Airbus A320 reject its takeoff in São Paulo. It later emerged that this occurred due to an engine failure, which occurred at a speed of just 20 knots.

More recently, in mid-March, a Transcarga International Airways Airbus A300 freighter experienced an uncontained engine failure that led to a rejected takeoff. Thankfully, its pilots were able to safely bring it to a stop on the runway in Bogotá, Colombia. The 37-year old cargo aircraft is yet to return to service, according to data from RadarBox.com.

However, these incidents are still ultimately an improbable phenomenon. Indeed, Boeing confirmed that they occur just once every 2,000-3,000 movements. Nonetheless, it is reassuring to know that safety frameworks surround them to ensure that, even when a takeoff is not rejected in the case of an issue, those onboard are at minimal risk.

Have you ever experienced a rejected takeoff? If so, what was the outcome of the incident? Let us know your thoughts and experiences in the comments.

Source : Simple Flying More