what is this "+" mark on B737 cockpit panel?
 

I've noticed that on the FWD overhead and main panel of B737-700, there are lots of " + " mark on the panel. (at least one on each plate)

example) under gear handle where flap limit speed is shown

FLAPS LIMIT (IAS)
1 - 250K
2 - 250K
+ (<-- this mark )
5 - 250K

what is this?
I couldn't figure it out nor find any information.
Please help my curiosity....thx

This has been answered a thousand times before.:hmm:

Here goes again. It is where the electrical connection is on the aft side of the panel. ie. It is where maintenance personnel push to make the connection when installing the panel.:ok:

thank you very much!! Nepotisim
 

Sorry I didn't do the research... anyway thank you very much!!!

Hi,when you don't have panel backlit you may also try to make a light pressure by your thumb on the "+", most of times It works fine fixing it in a while :)

Not sure about the 737, but the Airbus (330, 340, 320) have similar markings (very small blue colored "+" marks).

These marks are used by maintenance and aircraft recovery personnel to check for damage, misalignment, etc, following a hard landing, severe turbulence encounter, off-airport landing, etc.

They take precise measurements between the various marks "+", and compare to acceptable values. From there, they can tell if the aircraft is bent or not.

Again, not sure about the 737, but......

It would have to be a REALLY hard landing to bend the overhead panel in the flightdeck!

pappy j .. someone has made a right chump out of you.:}

mind you airbus are lightweight compared to the boeing's !!!!

Mumbo and PP. Nobody has made a chump out of me. Check the AMM manuals for the aircraft.

I never in my wildest imagination ever though that I would have to explain this to a bunch of people who profess to fly airplanes as a profession, but...

Airplanes bend during flight!!! When they become "Stressed" they bend, but don't return to their original (designed) shape.

By measuring between key places in the aircraft, engineers can determine if it is bent or not.

Next,

Apparently you haven't seen lightweight little A380 have you? Ever compared the operations cost of each? Seat by seat, Boeing looses!


Geeez, kids these days.

The "+" are alignment markers used by lasers during the etching/printing phase of the panel designs.

Normal stuff for CAD "Computer Assisted Drawings".

Just winding you up! It makes sense really, I just think the 'key places' must be somewhere on the fuesalage rather than 18 inches apart laterally on the roof of the flight deck!

Actually, there are thousands of these markings on a typical airbus, inside and outside.

Greetings
These Marks are called mass point if you press it provides a ground contact enabling current to flow thus the back light to come ON in case of faulty switch, i.e all panel is lighted except one plate, then press the + of that plate.
but to me the most important is why the upper panel has two colors Dark grey and light grey, it highlights systems affected by the Fire Switch:ok:

They are just Attention Grabbers to distract pilots of speed, attitude and engine power e.g. THY at AMS.

There's a good picture of both sides of the panel in the thread listed below.
Scroll down to bottom.

http://www.pprune.org/tech-log/37496...it-panels.html

no no no..

pappy j:} says it for checking airframe rigging due to when it flys it bends and doesnt return back to its normal design.

that is quite funny, the thought of checking airframe rigging in the flight deck against the panels.:D

Pee Pee. Are you really that daft?

Let me put it in simpler terms for you.

On the day that little yellow school bus that you were driven to that special school was build; when it was nice and new and exactly as designed, you could measure between various points throughout that bus (any point that was attached to the structure, super-structure or sub-structure), and record those measurements in a little note book (you probably colored in yours).

Then, after you drove that bus around - over a really bad road for instance - you could measure between those same points again. Then, you notice that several of the measurements differ from those recorded when it was new (in the regular school we called this geometry, trig, etc)

In aeronautical terms those changes in the measurements would lead us to believe that the structure had suffered some level of "Deformation" and those marks assist in measuring that deformation.

Next,

Why aren't they on all the panels?

Great thread :ok: Next ..... :p

Thanks for enlightening us all pappy j:}.

I suggest you also tell airbus aswell and get them to ammend the AMM ref
05-56-00 Inspection/Check of the levelling and measurement after abnormal operation of the aircraft.

Tell them to forget the datum points on the aircraft external structure and use the "pappy j:} + marks" in the flight deck.

Priceless :D

pappy j :}. Did your school report end "Please try harder".

That really is priceless :ok:

If so, wouldn't this process require more than one "+" per panel?

On all Boeing panels, the "+" does indeed align with the electrical contact. That is not to say that all panels have them.

Rgds.
NSEU

P.S. Tip: People casting aspersions on fellow PPRuNers' educations, should first check their spelling :ok: