Gotta love being stuck behind the locos in Europe. If they are in front you are snookered. They do a lovely fully managed descent CDA at 250kts and in sight of the field then ask for a short base and final and the rest of us are on the speedbrake. No doubt pat themselves on the back for all that fuel they saved and what wonderful airman they are. Seems airmanship and a bit of respect for other operators sharing the sky has long left this industry. Instead its a bunch of lemmings who are to scared to take the fuel they require to do the job properly. One day you might actually take the time to compare the fuel flow on a high speed descent at IDLE power with your 250kt version.

Playing a bit of a devil's advocate here, so... What is the optimum descend speed? Vmo, Vmo-5, Vmo-10? Supposedly I'm no. 3 for a straight in approach to XYZ airfield, and I have planned to fly at 340 kts, but now I'm stuck behind this slow guy doing 300 and I have to use speedbrake, bunch of idiots in front of me scared of the barber pole... How does it work in this case, where is the point where the speed becomes too slow?

Hat, coat...

PS: I agree we are all in the same airspace, but people with a lot of information about operating costs (much more than it's available to an average pilot) have come up with a cost index that keeps the boat afloat, and it might be different for another airline operating same aircraft type. It's then ATC's job to adjust the speeds to keep the flow going, sometimes the slow guys have to speed and and sometimes the fast guys need to slow down.

"Low power to save engine life and then full thrust if you are going to get a continuous climb.
High thrust on ground can cause much higher temps than in flight and temp = $$$."


Can someone explain this. Non jet driver here. I thought the EGT would be lowest at sea level due to highest air density and that EGT climbs as you climb in altitude.

Treble that cost. Depends also on hour to cycle ratio and operating environment, which being in Asia can be vastly lower than a benign environment. A ME3 engine for example, could operate for probably half the time as Euro-loco, which should go to the LLP limiter at 20K cycles (if operated at ~1.5 FH : 1 FC).

The higher you go, the less air there is, which means less fuel can be burnt, which means the fire in the can isn't as big, which means the EGT reduces.

The difference (savings) come from starting descent earlier (i.e. setting thrust to idle earlier) in a low speed descent. Since for a higher speed descent your calculated TOD will be further away than for a low speed one, you'll have cruise power for some minutes longer.

Just to clarify for anyone who may have had the same misreading as me initially, that's further away from the airplane before the decent starts, not further away from the airport