Acceleration in flight trials: Advancements in testing the long-range A321XLR jetliner
The Airbus A321XLR is gearing up for its entry into the long-range narrowbody market, with a comprehensive flight-test campaign underway to validate the aircraft's design and performance. Two flight-test aircraft, built specifically for this purpose, are at the heart of the campaign.
These aircraft, identified as VH-OGA and MSN11058 ('FTV2'), are being used to demonstrate the A321XLR's key features, such as its extended range, increased maximum takeoff weight (MTOW) of over 100 tonnes, strengthened landing gear, and fuel capacity enhancements. The aircraft have already undergone long-distance delivery and demonstration flights, showcasing an extended range of approximately 4,500 to 4,700 nautical miles.
The flight-test campaign covers a wide scope, addressing structural modifications, fuel system enhancements, engine performance, and flight handling characteristics. The aircraft are also being tested for fuel efficiency benefits, with up to 20% lower fuel burn per seat compared to the A321neo, supporting extended range capability and improved emissions performance.
The configuration of the production aircraft includes cabin layouts optimized for transcontinental and long-range narrowbody missions, carrying around 155 to 197 passengers, depending on airline specifications. The test aircraft likewise validate such configurations.
Industrial maturity is being secured in parallel to entry into service, including all jigs, tools, and processes in Airbus factories and those of the extended industrial chain and suppliers around the world. Ground lab testing is ongoing to finalise the serial standard modifications for the A321XLR.
Both FTV1 and FTV2 are aerodynamically similar to the A321XLR once the landing gear is retracted, as they have been retrofitted with the new inboard flap system. The onboard FTI suite in the A321XLR test aircraft can record and process up to 80,000 lines of data, fed by more than 1,000 physical measurement transducers installed throughout the aircraft.
The new water & waste system and new fuel system elements associated with the integral Rear-Centre-Tank are among the new non-flight-physics-related systems introduced on the A321XLR. Gary O'Donnell, Head of the A321XLR programme, states that the focus is on completing the construction and obtaining flight clearance for the remaining flight test aircraft by the end of this year.
The third new-build aircraft, MSN11080 (FTV3), is equipped with a 'lighter' FTI installation and will focus on maturity testing of the passenger cabin interior elements and route-proving for customers. FTV3 will demonstrate the aircraft's operation on the expected route scenarios for customers, especially on demanding ones to validate the aircraft's operation at the extremities of take-off weights, range, runway constraints, ground temperatures, and weather conditions.
The A321XLR's flight testing phase is necessary to become a long-range aircraft, as it involves increasing the A321's maximum take-off weight, uprated landing gear and braking systems, aerodynamic changes, and reprogramming of the flight control system. Customer services documentation and ground support equipment are being secured to ensure the aircraft is ready for use upon handover to customers.
Two more prototypes of the A321XLR development aircraft are in advanced stages of manufacture and will join the certification flight-test campaign. The global flight testing will be fully underway once all development aircraft are flying. The completion of these activities and submission of all final documents to the airworthiness authorities will allow for the validation and certification of the complete aircraft.
Notable flight-physics-related changes on the A321XLR include a simpler single-slotted inboard flap system, an electronically signalled "e-Rudder," and uprated landing gear, wheels, and brakes. Jean-Philippe Cottet, head of Flight Tests, states that they are certifying the two engine types in parallel on the A321XLR in the same timescale, which is a first in their history. The A321XLR is expected to enter service around 2023-2025.
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The flight-test campaign for the A321XLR involves testing the aircraft's features in the finance sector, such as its fuel efficiency, as it is projected to have up to 20% lower fuel burn per seat compared to the A321neo, leading to cost savings for airlines. In addition, the aircraft's extended range in the aerospace industry allows for longer flights, creating opportunities for new routes and increased revenue. The industrial chain and suppliers around the world are also ensuring the maturity of the production aircraft, ensuring a smooth entry into service for this long-range narrowbody aircraft.
