Jump to content

FMC ISA Deviation and Intersect


BaBene
 Share

Recommended Posts

Hi,

I've been playing around with the FMC lately and noticed two small thins that seem to be wrong from my point of view ;)

PERF INIT -> ISA DEV:

1.) When entering an ISA DEV of 0°C the FMC reads 32°F  0°C. Well 0°C is 32°F but what matters here is the deviation and shouldn't the deviation be 0°F as well?

2.) When entering a deviation =! 0°C the T/C OAT gets adjusted correctly, but when deleting the deviation with the DEL key the T/C OAT stays the same (i.e. does not revert to ISA OAT)

TAKEOFF REF -> INTERSECT

First of all I'm struggling to find a good explanation of what INTERSECT actually means and how to enter the data correctly. From my understanding it's used for intersection take offs (as the name suggests ;)) But then I don't really understand the format ---/-----. Could someone clarify this for me? ;)

1.) Basically the INTERSECT field just takes almost everything you throw at it. For example: Just press delete and click on intersect, it reads DEL/----- then. Or you might want to attempt to enter something after the "/" by entering "/200" for example, it then reads "/20/------".

 

Hope this helps!

 

Best regards,

BaBene

 

Link to comment
Share on other sites

Just noticed the following on a flight as well:

On 31.5.2016 at 11:39 PM, BaBene said:

1.) Basically the INTERSECT field just takes almost everything you throw at it. For example: Just press delete and click on intersect, it reads DEL/----- then. Or you might want to attempt to enter something after the "/" by entering "/200" for example, it then reads "/20/------".

I entered a 0 in intersect, thought to myself, "i don't really know what this does, let's delete that again."

Result:B733_9.png

I hope, that this image is helpful.

Regards, byte

Edited by byte512
clarified quote
Link to comment
Share on other sites

The intersect field will take data for a runway intersection takeoff - either the displacement in meters, or the name of the intersection.

In the real plane the position of the FMS will update to the runway beginning when you press the TOGA buttons. If you take off from an intersection, this update would be erroneous, since you are not actually at the beginning. So you can enter an intersection value (i.e. 900m) and the updated position will be correct.

If the FMS position is being fed GPS data, this update will not be taken into account - so it does not matter if you enter anything or not. The IXEG 737 will always have GPS updating, so entering anything (or nothing) into this field will have no effect.

Cheers, Jan

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...