Originally Posted by
dixi188
ISTR that the service ceiling was 35000ft, some VIP 400s were certified with higher cabin diff that allowed then to go higher.
If you were light enough to get to FL350 then the fuel burn was very low allowing a 4+ hour flight duration, but back at about mach .71
The 300/400s were the best performers.
I believe that Laker (300 series) developed procedures for Gatwick (or even Manchester) to Las Palmas/Tenerife, that allowed operation on such a 4+ hour sector that other operators found too far