Ascend by Cirium defines an aircraft’s Build Date as the Delivery Date to a customer, or the First
Flight date if more than 12 months have elapsed between the First Flight date and Delivery Date. The
12-month limit is intended to allow a reasonable period of time for interiors to be finished but excludes
aircraft that may have been used for flight test or demonstrator purposes.
Recent events have introduced a couple of challenges to the above described approach:
• The Boeing 737 Max grounding lasted approximately 22 months. Many undelivered 737 Max
aircraft that were built before or during the grounding remained undelivered long after the
grounding ended, due to needed modifications, and a complex return to service process that
was constrained by the capacity of FAA inspectors.
• The Covid-19 pandemic delayed deliveries because of border and quarantine restrictions as
well as airlines being temporarily unable or unwilling to take delivery of new assets due to their
precarious financial position. As a result, there was an accumulation of completed but not yet
delivered aircraft at several OEMs.
The aircraft described above may be delivered more than 12 months after their First Flight and thus
by default would have a Build Date matching their First Flight date. Our objective is to accurately
reflect how the market would view such aircraft.
Our research has established that from the buyer’s perspective, such aircraft are economically
equivalent to a new production aircraft rolling off the assembly line:
• The manufacturer storage process is more rigorous than that at airlines that have already
• Certifying authorities define the date of manufacture as the Delivery Date and therefore
maintenance clocks start on calendar items at delivery, i.e., it is delivered with “zero time”.
• In the instance that minor airframe and engine items differ from a new production aircraft,
manufacturers may offer compensation credits, extended warranty and guarantees that are
transferable in the event of a second-hand sale. In any case, such minor items have negligible
impact on the overall value of the aircraft.
We make exceptions on a case-by-case basis for some aircraft that are delivered beyond the 12-
month limit, provided that the manufacturer has satisfied a thorough list of storage and delivery criteria.
Any aircraft meeting the criteria is eligible for the exception, including the not-yet-delivered Boeing
737 Max aircraft among others. However, we shall not make such exceptions for aircraft that were
retained for flight test or demonstrator usage as these aircraft have already been “used” for a purpose,
and are typically sold to the client at some discount relative to standard production aircraft.
If the aircraft is being valued with the first flight date as the build date users of Values Analyzer will
receive a pop-up warning highlighting this fact prior to running the valuation. The pop-up will highlight
the length of time between first flight and delivery date and encourage users to contact Ascend. There
will also be a note in exports of online valuations of such aircraft to alert any third parties that may be
shown the online valuation.
For information about aircraft that may be candidates for the Build Date exception, or to obtain a copy
of the questionnaire for manufacturers, please contact one of the Ascend by Cirium analysts.