You could request a level block, e.g. FL90 – FL110. We do it all the time for airwork, military formations also often request block levels.
I’ll give it a go next time…I estimate I used 25% more fuel due to this stupid precise level concept…problem isI was causing interference with LEIB departures all along, which they can maange more easily with a single altiude (hence ATC’s insiting that we should be precise) . A couplt of departing commercial traffics got stop climbs 1000ft below me for a few minutes until clear. Surely block altitudes make that job more difficult, especially if they are not used to it
Perfect example on how to ride a wave in the most inefficient manner:
Even worse factoring the 50+kts direct xwind and straight track flown
Well , in the above trace you can see our average GPS altitude decreasing by about 70ft as we travel towards lower SLP while aiming to maintain FL100, but this is not a very extreme case…surely I can find a better one
Here is a better example about that with a strong wave when flying near Albenga towards Mallorca in a W-NW wind which basically killed our climb performance…then just as I was about to request a descent, the downdraft relented…
You can see a 700ft increase in GPS altitude as I was flying towards higher SLP while sort-of maintaining FL180.
The GS decrease at around 02:30 is due to a heading change into wind
The sudden GS decrease at about 00:37 is due to a heading change into the wind, the further continued decrease is due to the wave downdraft. I got down to Vy before it relented. In this occasion I did allow myself bigger altitude excursions without complaints from ATC. I did request a stop climb at FL180 from my initial planned FL200. I dont think I would have been able to achieve it.
Antonio wrote:
I estimate I used 25% more fuel due to this stupid precise level concept
How that compares to an alternative routing? (assuming you know you will hit a wave on direct routing)
Well, I suppose one could fly parallel to the swell on the updraft side, like gliders do, but that was some 20degrees off my desired track,
Perhaps a combination doing s-turns slowing down and turning parallel for a while in the updraft then turning straight downhill into the downdraft to the next wave then again crosswind for the updraft and so on would be the optimal path.
Good luck getting that approved on an IFR flightplan in class A in Palma TMA while crossing the departure paths of Ibiza and Palma airports…
Edited to reflect a truer representation…
