ISA deviation in DES forecast page

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Egyptair
Posts: 208
Joined: 08 Nov 2020, 13:54

ISA deviation in DES forecast page

Post by Egyptair »

Hello,

before descent, it is necessary to enter a value for ISA deviation beside arrival qnh and forcast winds.

I get the ISA deviation on my simbrief ofp for the origin airport, but not for the arrival airport.

Boeing states, that the value for isa is a mean between isa deviation at tod and destination , so it would be necessary to have this value
(ISA deviation at tod is available from the fmc btw)

From where do you get the ISA deviation value of the destination airport in real life ?

thank you

Ahmed
bravolima
Posts: 141
Joined: 15 Nov 2015, 21:13
Location: Zurich Area

Re: ISA deviation in DES forecast page

Post by bravolima »

Here you have a nice YT-Video about Forecast-Page:

https://www.youtube.com/watch?v=7g5ZFx61aFQ.

The rule of thumb can also be used with negative Temperatures

in real aviation the dat input seems not mandatory. I'm not sure about ProSim. I always put in data.
In a thread a while ago it was stated as mandatory for better accuracy in VNAV descents as far as I remember.

Bernhard
P3D v4.5 FDS: MIP, CDUs, Clocks, Shell, Liners, Tiller; CPFlight: Overheads, Pedestal; MCP, EFIS; OPENCOCKPIT: Pedals; FI: Brake-pressure, jaw-damper, compass; FCS: linked Yokes (mod); Weber-Seats, PROSIM: B737, +Utils +EFC737; AIVLASOFT: EFB 2,
Egyptair
Posts: 208
Joined: 08 Nov 2020, 13:54

Re: ISA deviation in DES forecast page

Post by Egyptair »

bravolima wrote: 10 Jan 2022, 19:24 Here you have a nice YT-Video about Forecast-Page:

https://www.youtube.com/watch?v=7g5ZFx61aFQ.

The rule of thumb can also be used with negative Temperatures

in real aviation the dat input seems not mandatory. I'm not sure about ProSim. I always put in data.
In a thread a while ago it was stated as mandatory for better accuracy in VNAV descents as far as I remember.

Bernhard
Thank you Bernhard
I am not sure , if prosim really uses this data , but I insert it too.

Ahmed
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