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Mission Statement 

The purpose of FLAPS-2-APPROACH is two-fold:  To document the construction of a Boeing 737 flight simulator, and to act as a platform to share aviation-related articles pertaining to the Boeing 737; thereby, providing a source of inspiration and reference to like-minded individuals.

I am not a professional journalist.  Writing for a cross section of readers from differing cultures and languages with varying degrees of technical ability, can at times be challenging. I hope there are not too many spelling and grammatical mistakes.


Note:   I have NO affiliation with ANY manufacturer or reseller.  All reviews and content are 'frank and fearless' - I tell it as I see it.  Do not complain if you do not like what you read.

I use the words 'modules & panels' and 'CDU & FMC' interchangeably.  The definition of the acronym 'OEM' is Original Equipment Manufacturer (aka real aicraft part).


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If you see any errors or omissions, please contact me to correct the information. 

Journal Archive (Newest First)
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Boeing Chart (Map) Lights - B737NG and Classic B737 Types

Chart lights (also called map lights) are attached adjacent to the overhead panel and are used to illuminate, in particular, the chart holders attached to the yoke during night time operations. There are two lights, one on the Captain-side and the other on the First Officer-side.

LEFT:  Chart lights removed from a Boeing 737-800 NG airframe.  Colour, appearance and design is different to the the older style lights used in the classic airframes (click to enlarge).

The light from the unit can be focused from a wide angle to a narrow beam by twisting the focus ring at the front of the light.  Each light can also be swivelled and moved vertically to position the light beam in a particular place on the flight deck (for example, chart plates).

The switches (knobs) that turn the light on and off are located on the siewalls of the Captain and First Officer side of the flight deck.  The light can be dimmed if necessary by rotating the knob.

The chart lights are mounted near each the eyebrow windows.

Two Styles (Classic and NG)

To my knowledge, there are two styles of chart light that have been used in the Boeing 737. The fatter style used in the classic series airframes and the more slender style used in the in the Next Generation airframes.  I have little doubt that there may also be small differences between light manufacturers.

LEFT:  Chart light removed from a Boeing 737-400 airframe.  The light has a differing focus ring, appearance and colour to the NG style (click to enlarge).  I believe this style of chart light is also used on the B747 aircraft.

The main aesthetic difference between the older 737 classic airframe chart lights and the newer NG style is that the older lights are squatter and a little fatter in shape; the NG style is longer, more slender-looking and has a smaller footprint.

Other differences are internal and relate to how the light is focussed on the lens and the physical shape of the focus rung used to alter the angle of light coverage.

Ingenious Design

Both style lights have an ingenious design to allow the light to be focussed.   Removing the rear plate of from the older style light reveals the inner side to be a circular reflector dish (see image) which evenly distributes the throw of light when the unit is set to wide angle. 

LEFT:  Chart light showing reflector dish on inner side of end cap.  This style is the older light type used in the 737 classic airframes (Click image for larger view).

The newer Next Generation style lights use an aperture blade which either enlarges or contracts as the focus ring is turned.  This design is identical to how a camera aperture works.

Both styles can use either a 12 or 28 Volt bulb; the later will generate a brighter light.  Connection is direct to the power supply (12 or 28 Volt).  An interface card is not required.


Original Equipment Manufacturer (OEM)

Put bluntly, you cannot achieve a more realistic end product than when using a real aviation part.  Genuine parts, although at times difficult to find, are built to last; if they can withstand the continue abuse of pilots in a flight deck then they are more than adequate for home simulation use. 

LEFT:  The NG style chart light.  A blade aperture controls the amount of light that is reflected onto the thick lens glass (click image to enlarge).

It's true that while some parts appear "used" with faded and missing paint, they can easily be cleaned up with a fresh coat of paint.  Personally, I prefer the worn-appearance.

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Reader Comments (4)

Hi willow

I've been following this blog for years now and I am looking forward to every new entry.
I have a question regarding the map light and the chart light.
First of all, I think in this entry you are mixing up the chart light and the map light. From what I understand the two lights in the eyebrow cutouts left and right of the forward overhead are actually the map lights and the chart lights illuminate the narrow clipboards on the sidewalls attached to the sliding windows.
But anyhow, I had a hard time figuring out where these chart lights are actually located. Steve Cos over at the FDS forum just informed me that they are bulbs integrated in the sliding window top frame, reflecting of a small mirror downwards onto the chart holders.
Did you solve it that way? That would sound pretty complicated. I suppose one could also just mount another map light to the ceiling and focus it on the clipboard.

Thank you & greetings from Germany
August 21, 2017 | Unregistered CommenterTony Flare
Thanks Tony

First off, the naming of the lights depends upon who you speak with and what documentation you read :)

I have not heard about the lights that Steve Cos has discussed. I do not have these installed as I am not using an enclosed shell at the moment. Time to do some more reading :)

The lights in question can be focused from a narrow beam to a wide beam.

Glad you like the website, F2A
August 24, 2017 | Registered CommenterFLAPS 2 APPROACH
Thank you willow.
I obviously didn't have it on the radar that you haven't approached the whole shell issue. Time to do even more reading..:-)
Do you think you will go with the FDS shell in the long run?
Here is the thread from the FDS forum regarding the chart light issue:
August 25, 2017 | Unregistered CommenterTony Flare
Hi Tony

Thanks for the link.

I did some reading and the only mention is the map/char lights discussed in the post. These lights are mounted near the eyebrow windows and can be maneuvered so that the light reaches a particular area (chart plate on yoke or elsewhere). The knobs which control the light are mounted on the left and right side wall on a panel.

Steve is probably correct as there are two knobs on the panel.

Next time am in the real flight deck I will ask and look....

I have not thought too much about a shell as I a still working on the overhead, Cheers, WilloW
August 25, 2017 | Registered CommenterFLAPS 2 APPROACH

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