So from watching many videos in the cockpit on YouTube I have noticed that pilots will say stuff like "Loc Blue" or "2500 Blue" but what does this 'blue' mean and are there any other colours?

These images are form this video at 3:43 and 4:25.

enter image description hereenter image description here

  • 3
    $\begingroup$ Please include the link to the video you are referring to. $\endgroup$
    – Simon
    Commented Jul 9, 2017 at 7:19
  • $\begingroup$ youtu.be/Dx7G8O6cXqk Reference to this video at 3:43 4:25 $\endgroup$
    – Jack
    Commented Jul 9, 2017 at 8:09
  • 1
    $\begingroup$ Please edit your question to include relevant information rather than use comments. I've done this for you now. $\endgroup$
    – Simon
    Commented Jul 9, 2017 at 9:19

2 Answers 2


At the top of the Primary Flight Display (PFD, the one with the artificial horizon in the center), there is a so-called Flight Mode Annunciator (FMA) with several columns indicating currently active and armed modes of flight guidance:

Flight Mode Annunciator

The first line shows active modes (in this case: SPEED, ALT, and HDG) in green color. The second line has additional information about armed modes in blue color, which will become active later, for example LOC (localizer) mode will become active instead of HDG upon localizer capture.

The callout from the pilots like "LOC blue" serves to remind themselves of the current flight guidance modes, and to maintain awareness of mode changes. This is also to ensure that their mental idea of "what the aircraft will do next" is up to date and fits to the current flight situation.

However, I'm not sure about the "2500" you mentioned.

On youtube you can find videos like this one explaining a bit more about the FMA. (screenshot taken from there). As the comment by @DeepSpace mentions, the screenshot and video mostly apply to Airbus aircraft. Other aircraft may have similar displays about flight guidance modes, but I am not aware of their specific color codings.

  • 4
    $\begingroup$ Might worth pointing out this answer (and question) is mostly relevant to Airbus aircraft. Also, the "2500" probably refer to LOC capture altitude. $\endgroup$
    – DeepSpace
    Commented Jul 9, 2017 at 8:45
  • $\begingroup$ From the caption on the 2nd photo, I'd say the "2500 blue" refers to the selected altitude on the FCU, which will show as a cyan 2500 above the PFD's altitude tape. The autopilot will descend and maintain 2500 ft, at an unspecified rate of descent ('Open descent'). $\endgroup$
    – Deeday-UK
    Commented Jul 9, 2017 at 14:07

Airbus uses "blue" in three different callouts, but with slightly different meaning.

  • "LOC blue" or "GS blue",etc, reffers to the armed modes of the F/D. It's just another way to say "localizer mode is armed and will be active once established on the signal"

  • "2500 blue" reffers to the altitude selection on the FCU. It specifies that 2500 feet have been selected, but blue here has a slightly different meaning: user selected altitudes are shown in blue on the PFD, where altitude constraints from the FMGS are magenta. A similar call eg. "4000 magenta" would imply "we will stop and capture 4000' because of a constraint"

  • "ecam memo?" "landing no blue" reffers to the landing (or t/off) memos displayed on the ecam. Uncompleted items appear in blue, completed in greeen. "no blue" here would mean, well, no incomplete items.

So as a quick answer: "blue" term means that something is displayed in blue on the screen


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .