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Author Topic: Polar Diagram - how is it calculated?  (Read 22136 times)

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Runway 31

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Re: Polar Diagram - how is it calculated?
« Reply #30 on: September 21, 2015, 02:34:34 PM »
John,

I am going to hazard a guess and suggest that in colder weather the aircraft climb performance is better and the contents of http://www.skybrary.aero/index.php/AP4ATCO_-_Factors_Affecting_Aircraft_Performance_During_Takeoff_and_Climb  may offer an explanation which I hope may be relevant to your question.

Alan

neroon79

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Re: Polar Diagram - how is it calculated?
« Reply #31 on: September 21, 2015, 04:49:35 PM »
Your are right Alan,

Cold air has a higher density than warm air, that's by the way the reason why Emirates boss is complaining about the performance of the bigger dreamliner versions. In hot desert air the density and therefore the "air lift" and engines thrust performance is that low, that the dreamliner won't take off if full cargo is loaded in the airframe.

Ingo
Greetings from northern Germany, Ingo
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FACTflights

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Re: Polar Diagram - how is it calculated?
« Reply #32 on: September 22, 2015, 07:58:09 AM »
Alan,

Very interesting indeed, so my assumption was correct.

We have mountains all around us except to the South.  Table Mountain is about 5 kM to the West and the other mountains start at about 80kM to the east.  To the North we have a small gap through which we see the BA flights to EGLL.

The aircraft have to gain altitude pretty quick to clear the high points.

To the South we see the flights to Anarctica.
John
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We live under a rock:  Table Mountain

Icom IC 706 Mk II G; Icom IC 726; Icom IC T22E; Yaesu 290R; Alinco DJ-V5 
No HF antennae at the moment.

FACTflights

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Re: Polar Diagram - how is it calculated?
« Reply #33 on: September 22, 2015, 08:01:31 AM »
Screen shot
John
ZS1AGH
We live under a rock:  Table Mountain

Icom IC 706 Mk II G; Icom IC 726; Icom IC T22E; Yaesu 290R; Alinco DJ-V5 
No HF antennae at the moment.

Runway 31

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Re: Polar Diagram - how is it calculated?
« Reply #34 on: September 22, 2015, 08:27:37 AM »
Yes the surrounding terrain will impact on what you see as well.

Alan