Boeing will push back delivery of the first 747-8 Intercontinental to the first quarter of 2012, and of the 787-9 to early 2014.
"The 747-8 remains on track for certification in the fourth quarter," said Boeing. "First delivery is now scheduled for the first quarter of 2012 due to a delay in flight testing and the time required to incorporate all flight-test driven changes."
On 12 October, Boeing Business Jets president Steve Taylor said the first 747-8I, destined for a VIP customer, will be delivered at the end of 2011.
The company added that it is still committed to "incorporating engineering and design changes identified during flight testing" before the 747-8I's certification.
Following the 787-9's critical design review, Boeing said the first delivery is "expected in early 2014, although we continue to look for opportunities to regain schedule".
In July, a Boeing spokeswoman said that late 2013 remained the target for delivering the first 787-9 to launch customer Air New Zealand. She qualified her remarks, however, saying that the company is "continually re-assessing that schedule".
The disclosures were buried on pages 35 and 36 of the airframer's 55-page 10-Q filing with the US Securities and Exchange Commission. The filing pertained to the company's fiscal third quarter ended 30 September.
The company will continue to assess the impact of prior 787 schedule changes with suppliers and customers, including the discussion of contractual relief "related to delivery delays and supplier assertions".
Boeing said it still deems the fourth, fifth and sixth 787 flight test aircraft to be "commercially saleable", but warned that charges could be incurred if it decides one or more of these aircraft cannot be sold. Owing to significant re-work and modifications to the first three 787 test aircraft, in 2009 Boeing said these three 787s could not be sold, although the company had previously expected to do so.