737 Engine indicators
 

What are the small dots on the analogue primary instruments?

Test position?

Just a touch vague!!:ugh:

737 Type?
Instrument/s in question?
position of dot?

On the one hand, I can't help feeling that this question needs to be shifted to another forum, harumph. :ugh:

On the other, we can probably suggest that the spotter/flightsimmer asking the question visits the powerplant page on a very good 737 website. :ok:

If you are talking about non EFIS (analogue), then you may be referring to the red warning lights which are situated inside the indicators on the N1, N2 and EGT indicators. These lights illuminate when an engine paramater has been exceeded and remaim on until the parameter is reduced below the limit.
On the EFIS displays the ‘dots’ are situated above the indicator and do the same job.
If you are talking about something else, then I am stumped.

Sorry about th "vagueness". I was in a bit of a rush. I was refering to the dot at about 1 o clock on all of the primary engine instruments on an analogue aircraft.

737 Engine Indicators
 

Hi Screwdriver,

If the 'dots' are at about the 2 o clock position on the primary engine instruments, it could well be the light sensors that control the brightness of the LED numerical display on that indicator.

Hope this helps.

White dots
 

If the dot is on the glass of the indicator(s), along with the color markings or bands, it could be a slipage mark. That way if the glass rotated, moving the markings, you could tell. Just a guess