Boeing and Airbus suffered major order cancellations last month, with airlines dropping 25 Dreamliners and seven A350s, according to data released by the aircraft manufacturers on Monday.
With 25 cancellations of 787 Dreamliners by clients not named, against 19 orders so far this year, Boeing is in negative territory for its flagship aircraft built largely with composite materials that it says will use 20 per cent less fuel than similarly sized aircraft.
At $193.5 million (148.3 million euros) apiece according to list prices, the cancellations are a $4.8 billion hit on the US manufacturer's order book.
Boeing did not comment on the latest order figures.
For its European counterpart, the cancellation of seven A350-1000 aircraft by Abu Dhabi-based Etihad Airways represents a loss of $2.2 billion at catalogue prices.
The Emirati airline canceled six other A350-1000 aircraft at the end of last year. Airbus said the airline was going through with 12 of the 25 planes it ordered in 2008.
Airbus also declined to comment on the order figures for the A350-1000, a new aircraft it began assembling last month which also includes many composite materials.
The first A350s are due to be delivered in 2014.
Boeing retained a large advance over Airbus in terms of orders received this year. Boeing's orders stood at 415 on May 1 against 95 for Airbus on April 31.