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Odd altitude calls from ATC
http://www.ocs-support.co.uk/forums/viewtopic.php?t=2065		 Page 1 of 1
Author:  martinlest [ Sat May 21, 2016 2:22 pm ]
Post subject:  Odd altitude calls from ATC
Still getting some odd flights, with respect to ATC altitude calls - the latest was from VOTV - VRMM. I looked at the FP waypoint adjustment page after, but no clue there:

VOTV 13
0876E 30000
NOKID 30000
XXX 30000
MUGBA 12000
VRMM 10

looks OK next to my flight plan.... but I was only cleared to 29000. The clearance to 30000' didn't come until NOKID, by which time I had been at FL290 for the best part of the flight. NOKID, moreover, is right next my TOD and sure enough, I got my descent instructions almost immediately after the call to climb to 30000 (I didn't even make it up to 30000).

I wonder why ATC didn't instruct me to climb to my cruise level until I was just about to be told to descend to my destination. Log attached (level 2).

Oh, one other tiny little thing. :D Does anyone else get this...

Most flights I get my call sign (e.g. "Springbok 255") repeated to me by ATC for no apparent reason, usually after the end of a message. That's to say, ATC makes some kind of acknowledgement, usually ending with my callsign, then there's a pause of several seconds, and ATC repeats my callsign again. Odd. Only started with 3.1.15.... As I say, an oddity rather than a serious glitch!, but if it's easy to locate why this happens and stop it, that would be nice also!

Many thanks,

Martin
Author:  martinlest [ Sun Jun 19, 2016 3:54 pm ]
Post subject:  Re: Odd altitude calls from ATC
OK then, some more odd altitude calls. Flying SLLP to SLCB. My cruise altitude is 24000'. I have SIDs (DPs) active... ATC cleared me to FL190, but even though there was plenty of time, I never received an instruction to climb any higher. The FP Adjustements window showed I should be at FL240 at the first waypoint CAL...

When it came time to descend, ATC told me to descend to FL190 (even though I was already at that height). The pilot's response was "Out of Flight Level 190 for Flight Level 190".

I attach the logs. Anything obvious to explain this?

Thanks,

Martin
Author:  Dan77 [ Sun Jun 19, 2016 4:28 pm ]
Post subject:  Re: Odd altitude calls from ATC
martinlest wrote:
I was only cleared to 29000. The clearance to 30000' didn't come until NOKID, by which time I had been at FL290 for the best part of the flight.
A quick response to your first question: This happened to me as well on a recent flight. PF3 uses an element of randomness in calling the step-climbs to your cruise level, so each flight will be a bit different. From the User Guide:
Quote:
Please Note: During extensive testing we have found it best to have your cruise altitude set from your very first waypoint and allow PF3 to handle its internal step climbs. This saves you the hassle of having to enter step climbs manually.
and Features:
Quote:
• Intelligent step climbs and descents which will be slightly different each time for added realism.
If you repeat the flight you may be cleared to cruise before your first waypoint. Other times you may not. You can also experiment by trying a lower cruise level and/or adding some more waypoints.
Author:  ThomasAH [ Sun Jun 19, 2016 5:27 pm ]
Post subject:  Re: Odd altitude calls from ATC
I don't know about the first flight (I think I have looked it some time ago and did not find obvious reasons, but I'm not sure), but in your second flight I think I can see the reason for this behaviour:
You climbed quite slowly, so by the time you reached FL190, PF3 just wanted to give you the next step (FL220) towards your cruise/WP1 altitude, but then calculated that it is about time do descend. The "descend to" probably happened, because PF3 already considered you on your way towards FL220.
Author:  martinlest [ Sun Jun 19, 2016 5:52 pm ]
Post subject:  Re: Odd altitude calls from ATC
Yes, thanks both - not to worry about the first flight too much: It's quite old and I don't really recall what happened. I posted here rather than start another thread with a similar subject..Not sure about your analysis of the later flight though. I don't know exactly what the logs show, but I spent quite some time at FL190 before being given any further instructions. There would certainly have been time to reach cruise altitude and stay there for several minutes. Of course it's quite a short flight from SLLP to SLCB. I don't recall climbing all that slowly, but I used the VNAV for this flight. Since the take-off altitude from La Paz was over 13,000', the climb rate may have been slower in the thin air..

M
Author:  vololiberista [ Sun Jun 19, 2016 7:19 pm ]
Post subject:  Re: Odd altitude calls from ATC
The given flight plan itself is not helpful. You have waypoint.2=Fix01, I, S17* 9.18', W67* 7.42', +000000.00, Which is not in the FS9 database. Also the current published airways have little correspondence to those in the FS9 database as well. So you would need to enter DAKOG and TEDOK into FS9.
This is a very short flight so your cruise altitude is a bit high unless you have a high performance a/c. I would suggest FL180 or at most FL200. It depends on your a/c performance. Bear in mind that the VC10 is/was the only hot and high performance jet built and is/was probably the only commercial jet that could carry a full compliment out of La Paz. Even so the initial cruise climb out of La Paz with a full passenger load would be less that 1,000fpm. Don't expect normal climb rates from any a/c.
If you're flying a 737 for example you could probably take one passenger perhaps two at a pinch! Anything bigger won't cut the mustard!
The fpl below includes a SID which you can programme into PF3

SLLP-->DAKOG2-->DAKOG UW677-->TEDOK-->SLCB
So my recommendation is the above fpl at FL180. The DACOG2 departure gives you 69nm to get to cruise. You'll need every inch of that. Oh and remember that at El Alto you must be on oxygen until the cabin has reached the requested pressure.
Author:  martinlest [ Sun Jun 19, 2016 8:18 pm ]
Post subject:  Re: Odd altitude calls from ATC
Quote:
The given flight plan itself is not helpful. You have waypoint.2=Fix01, I, S17* 9.18', W67* 7.42', +000000.00, Which is not in the FS9 database
I gather that doesn't really matter?:

viewtopic.php?f=8&t=2096

.. but, having just gone back to FS9 to check what you say, the reason I didn't see DAKOG & TEDOK is that I had waypoints turned off in FS Navigator! No idea how that happened, I usually have everything visible. Had I seen them, I would have used them: I am going to redo my flight plans now..

However, given that PF3 is supposed to be able to use any waypoints, real or not, I am not convinced that that is why I didn't get any instruction to climb to FL240. According to FSNavigator, FL2340 is perfectly reasonable for this flight plan (and my B737) - there is almost 55 miles of cruise altitude there. In any case, the terrain is so mountainous that a cruise altitude of 180 would be almost scraping mountain tops! Bear in mind my take off altitude is over 13000' (as you are aware, I know). At that altitude, yes, I planned a climb at about 1000'/min, but using the VNAV function it was, as far as I recall, often a lot steeper than that. In any event, I had plenty of time sitting at FL190, waiting to go up to FL240. I think from what I saw on the screen, FL240 for cruise latitude was perfectly feasible.

Thanks for the reply! :-)
Author:  vololiberista [ Mon Jun 20, 2016 9:47 am ]
Post subject:  Re: Odd altitude calls from ATC
When flying from a high altitude airport treat the a/c as if it is at maximum auw. Smooth rotation, don't snatch it. Keep the airpeed at or below the flap limits. Keep within the V speeds. Only reduce flaps as the airspeed passes the flap limit. Shallow turns not more than 20deg. If your a/c doesn't have FADEC then be careful not to exceed the engine limitations. Once you are onto your normal cruise climb throttle setting you can begin to relax.
Author:  martinlest [ Mon Jun 20, 2016 9:54 am ]
Post subject:  Re: Odd altitude calls from ATC
Yes, I had no problems with takeoff thanks (except when I tried using FLEX settings in an airbus: I changed the FLEX takeoff temperature setting, and all was fine, or I can set the gate to TOGA). The flights I mentioned here were in a B737... but I still set the take off temperature lower than the ambient in the CDU and got plenty of power.
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