x marks the spot

[Captain_al]

Does anyone know what the little "x"'s are on the overhead instrument panel for various different systems panels. For example on the pneumatics panel it is slightly up and to the right of the APU lettering for the Bleed Air. I have some theories, but I never noticed them before.

[Jeroen Hoppenbrouwers]

They mark exactly where under the panel a connector is located for the backlight power. When the backlight stutters, tap there with the rear end of a screwdriver.

[Hardy Heinlin]

By the way, those "+" crosses seem to be an invention of Boeing. I never saw them on other aircraft. Is this feature a relict of the steam gauge era when pilots had to knock on the panels more often? :-)

Actually, I thought the primary purpose of that cross is to help during the installation: When you move the panel into the frame, push where the cross is because that's the area where the connector is.

[Captain_al]

My buddy was right, he mentioned that, thanks Hardy and Jerone!

He did mention a throwback to the 727 when they could remove panels.

[Walter Kranl]

See also

https://aerowinx.com/board/index.php?topic=90.msg802#msg802

Regards
Walter

[Magoo]

So the legend is true...