|Quoting Icelandair75w (Reply 64):|
I've heard EK changed from the 777-300 to 77L due to low bookings. Must just be for the winter, with a possible upgauge to 773 for the summer.
|Quoting clrd4t8koff (Reply 72):|
I don't know why they sent it, but curiously enough there is another thread started that today's DXB-GLA flight was also downgauged from the 77W to a 77L. Perhaps there's a few 77Ws in mx that required shuffling around some aircraft? Not really sure. For BOS EK only had 1 other option - the 77L. They couldn't send an A380 and the A332 is too small (pax & cargo) for that range. So the 77L it was.
EKs currently 107 strong (!!!!) 777-300ER fleet is composed of 36 aircraft with higher MTOWs and the mandatory aft overhead crew rest for flights above 12 hour block time. 6 of these aircraft are 349t MTOW and the other 30 are 351t MTOW (the highest MTOW Boeing offers). Hence only these 36 aircraft are dispatched on the DXB-BOS-DXB flights.
going to the A388, there was quite some slack for a while in this fleet, which EK
internally designates the -300ULR. However, with recent changes including BOS
, the fleet is now in significantly higher demand. Operationally they are rotated anywhere from 1h DXB
flights to 14hour DXB
flights and any other route you will commonly find the 3 class configured 340t MTOW birds on.
has had quite some lead time planning ahead for the second daily BOS
flight, delays down route and -300ULR aircraft having to swap in for other -300ERs, have left EK
with a shortage for a few days.
Anytime a aircraft is delayed or goes technical, and there are swaps taking place (daily occurrence for a operation this size), the results of which are like a domino effect that takes a few days and sometimes weeks to go back to the originally intended rotation for a aircraft, which in itself is based on operational factors such as certain routes requiring certain aircraft, maintenance etc.).
Furthermore it is essential that the -300ULR fleet does its share of non-ULR flying because doing at or near MTOW departures out of DXB
in 30-40C temps would result in far too many TOGA takeoffs thus bringing the GE90s on the -300ULR fleet into the shop at a far greater rate. Something that is avoided thanks to the dispatch and fleet planning software making sure that the ULR fleet is rotated through the system accordingly. This resulting in the best balance between airframe cycles/hours and ensures that the engines on this fleet are operated with the intended on wing time between shop visits.
The 10 strong -200LR fleet is of course also fitted with a aft upper crew rest and thus is the perfect and only substitute for the -300ULR, as in this case for a few days!
Side note: When Delta received its MD-11s and struggled with the LAX-HKG westbound sector, due to the MD11s performance shortfalls (specifically the engines) they designated two or three frames to operate that sector with increased MTOWs and if I recall correctly a additional AUX tank (hence the MD11ER designation) and the various other PiP (performance improvement package's) that MD gradually developed (under great pressure). However, because these two/three aircraft were the only ones in the fleet capable of operating this flight with a meaningful payload, they were exclusively used on this rotation. The result of which was at/near MTOW departures on every flight and hence almost always requiring TOGA thrust (especially out of LAX). This resulted in a far more rapid performance degradation of the already under performing PW4460s and hence offset quite a bit of the fuel burn improvement achieved with the PiPs.[Edited 2015-10-01 22:16:04]
[Edited 2015-10-01 22:16:50]