So-called white-tails are considered an alarm signal in the aerospace industry because they usually signify that they have been built without an airline in place to operate them, though in rare cases buyers can decide to paint them elsewhere.

Because of past downturns, planemakers have learned to build only what they have sold so nowadays the sight of a white plane, especially a recent model like the A350, is extremely rare.

In this case, the aircraft has been sold to one of the world's largest leasing companies, AerCap (>> AerCap Holdings N.V.), according to online records of the serial number on the tail.

AerCap had arranged to lease it to SriLankan Airlines but its fate was thrown into doubt when the carrier said this year it had cancelled a lease for 4 A350s from AerCap and no longer intended to buy a further 4 from Airbus due to steep losses.

The Dublin-based lessor is unlikely to be out of pocket since the Sri Lankan government said last month it would pay millions of dollars for cancelling the lease.

But industry sources said the flexible white design raised questions about where the aircraft was headed next, which in turn echoed deeper concerns about a drop in demand for big jets.

Some online reports however say the jet is headed for China.

A spokeswoman for AerCap declined to comment.

The unconfirmed fate of the former SriLankan jet is a reminder of the struggles some carriers face amid fierce competition.

Its appearance in white just yards from a high-profile company ceremony was apparently an accident of scheduling in the busy Airbus delivery centre, which pumps out two planes a day.

But it struck a jarring note in an otherwise upbeat event to mark the first flight of the latest A350-1000 model, betraying a flaw in the rigid on-message flavour of such ceremonies, and intruding on the celebration like a ghost of past recessions.

"It is hard to see how that is a comforting omen," an aviation industry source said, asking not to be named.

Without confirming whether the aircraft was destined for AerCap, an Airbus spokesman said: "We do not comment on our customers' customers (and) we always deliver our aircraft to the customer's specifications."

Airbus, Boeing and many lessors say that although demand for large jets has slipped recently, the longer-term prospects for long-haul travel are robust and that jets like the A350, one of the newest types available, rarely stay unused for long.

(Reporting by Tim Hepher; Editing by Alexandra Hudson)

By Tim Hepher

Stocks treated in this article : Airbus Group, Boeing Co, AerCap Holdings N.V.
Stocks treated in this article : Airbus Group, Boeing Co, AerCap Holdings N.V.