The Third Airbus A321XLR Prototype F-WWAB, MSN 11080, performed its rejected Takeoff test in Hamburg-Finkenwerder yesterday. The airplane joins two other testbeds, WXLR and WWBZ, to complete all the necessary testing for certification.
It’s interesting to note that this XLR has a much more typical Airbus house livery, in contrast to its two sister ships which both sport city skyline decals, pertaining to their ability to connect far-off places.
A Rejected Take-Off (RTO) is usually thought of as one of the hardest tests an airplane has to undergo for its certification trials. The RTO test is performed under the worst possible conditions, such as fully worn-out brakes, an aircraft loaded to maximum takeoff weight, and no use of thrust reversers.
During an RTO test, most of the kinetic energy of the airplane is converted to heat by the brakes, which may cause the fusible plugs of the tires to melt, causing them to deflate. Small brake fires are acceptable providing, in the first five minutes, they do not prejudice the safe and complete evacuation of the aircraft.
The Airbus A321XLR will have a range of 4,700 nautical miles (5,400 miles) and be able to fly nonstop routes for close to eleven hours. This makes city pairs such as New York-Rome, Delhi-London, and Sydney-Kuala Lumpur possible while retaining the superior single-aisle economics of a narrowbody. The XLR can fly around 30% further than an A321neo and 15% further than an A321LR, so it does need to carry more fuel, increasing the maximum take-off weight (MTOW). The heavier MTOW means upgrading, among other things, the landing gear and braking systems, which have to be flight-tested and certified.
The A321XLR also complements widebody aircraft by serving the same routes at off-peak times or in cases of significant seasonal variation in demand.
Airbus will have four prototypes in total as it works towards certification of the type. On June 15, the first prototype successfully completed its first test flight. The aircraft is now starting its flight test campaign en route to secure Type Certification in 2023 and entry into service in 2024.
What is a rejected takeoff?
An RTO or Rejected Take Off, is a flight maneuver in which the pilots will stop the aircraft and discontinue the takeoff. There can be multiple reasons why such a decision is made. This can include engine failure, engine fire, major system failures, plus other scenarios. There are a few RTO scenarios elaborated below:
- The Go/Stop Decision
- In the scenario of engine malfunction, the recognition of a significant abnormality, or an ATC instruction to stop the aircraft during the take-off roll.
- Continuing the Take-Off
- Once a correctly calculated speed has been exceeded, the takeoff must be continued and should allow the aircraft to get safely airborne and climb away.
- High-Speed RTO
- Once at high speed, it is usually decided that a takeoff will only be rejected for major malfunctions such as an engine failure or fire – or at the discretion of the pilot in command in the event that a similarly serious situation is occurring.
- Low-Speed RTO
- It is planned that the takeoff will be rejected for a significant malfunction or abnormal situation within the lower speed range; it is highly likely that directional control will be largely dependent on the use of the nose gear steering system.
You can read more about Rejected Take Off here.
Sources: Twitter, Skybrary, Airbus, RoutesOnline