Watch: Air-to-air footage of the world's weirdest plane, the Airbus BelugaXL

New footage of the three-storey tall BelugaXL has been released as the whale-lookalike continues its flight test campaign.

The plane-maker says it features one of the most voluminous cargo holds of any civil or military aircraft flying today, the Airbus Beluga offers a unique way to transport oversized air cargo.

It is based on the Airbus A330 but its bulky fuselage means its top speed is limited to around 860kph rather than in excess of 900kph.

Its predecessor, the A300-600ST Super Transporter, has been flying for the past the 20 years.

Belugas carry complete fuselage sections, wings and tails of Airbus aircraft from different production sites around Europe to the final assembly lines in Toulouse, France and Hamburg, Germany.

The new plane is bigger with an 8.8m hold. Airbus is expanding the fleet as it steps up production of widebody planes, the A330 and A350 XWB.

In addition to the significant use of existing components and equipment, Airbus' new A330-based BelugaXLs will incorporate newly developed elements including its lowered cockpit, an enlarged cargo bay structure, and modified rear and tail section.

The first Beluga XL performed its maiden flight a week ago. The first of these aircraft planned to enter service in mid-2019 – initially operating in parallel with the existing A300-600ST fleet, which is to be progressively retired through 2025.

The Beluga is operated by a three-member crew comprising two pilots and a loadmaster.

Also included in the cockpit are controls for a transportable heating module that can be installed in the main deck cargo compartment. The module provides temperature-controlled conditions for sensitive payloads carried by the Beluga, including satellites and paintings.