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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).

 

All funds are used to offset the cost of server and website hosting (Thank You...)

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Journal Archive (Newest First)

Entries in Next Generation (2)

Tuesday
Sep202016

White Caps for Locking Toggle Switches on Overhead

It has taken a very long time to collect the assortment of OEM needed parts to complete the forward and aft overhead panels.  Finally the build is now in progress and it’s hoped completion will be towards the end of 2016.

LEFT:  Lower electrical panel showing reproduction latex-style cap (ELEC 2) and OEM Honeywell Switch Accessory 15PA90-6W (ELEC 1). Click to enlarge.   For those with keen eyes - yes that is a voice recorder in the lower panel - more to follow in later posts.  Of interest are the two different white caps (read main text). 

Earlier on, I had purchased several dozen Honeywell toggle switches, however, for whatever reason the white caps on the toggles were either missing or damaged.  I was intending to use reproduction white push-on caps (aka white condoms), but the caps failed to  fit snugly to the OEM switches, and their appearance was slightly different to the OEM version - the ends of the caps looked rather bulbous.

My next choice was to use latex caps that are used in automotive industry.  Once again, the appearance was slightly different and the automotive caps sported a small nipple at the end of each cap where they had been connected to the plastic retaining spur; I found the appearance of the nipple disconcerting.

Short of viable options, I purchased the OEM white caps from Honeywell which is the company that supplies Boeing.  If you carefully look at the above picture of the lower electrical panel (click image to enlarge picture), you will observe the nearest toggle switch has been fitted with an automotive style cap; the nipple and joining line is clearly visible.  The second toggle switch is fitted with the Honeywell white cap.

OEM White Cap Anatomy

The reproduction slip-on caps currently available on the market bear little resemblance to those made by Honeywell.

LEFT:   Honeywell Switch Accessory 15PA90-6W showing internal screw thread.  The thread screws onto the stem of the toggle switch (click to enlarge).

Most of the reproduction white caps are either a push-on condom style, or are a white-capped head attached to a slender hollow shaft.  The shaft then slides over the existing switch stem.

The Honeywell caps are not slip-on latex but a solidly-produced head with an internal aluminium thread.  The head is designed to be screwed directly to the shaft of the toggle switches.  Firmly attached to this head is the white latex cap. 

Mounting

To mount the white cap on a toggle, witch you must first gently heat the switch stem which will loosen the head of the toggle.  It then is an easy matter to screw off the head and replace it with the OEM head.

Measurements

Not everyone wants to utilise OEM parts.  As such I have provided the measurements of the switch head (courtesy of Honeywell) for those who wish to try their hand at making their own white caps.

As the overhead build continues, I will be posting more articles that showcase the overhead and the various panels and functionality.

If you are searching for the other syle of white caps used on the overhead, the part number is 69-44578-2.

Glossary

Honeywell – Avionics conglomerate that is heavily involved in the defence and aviation industries.
OEM – Original Equipment Manufacture (aka real aircraft part).

Tuesday
Dec012015

Major Differences Between Classic and Next Generation Throttle Quadrants

The advent of high quality reproduction parts in association with advanced avionics suites produced by companies such as ProSim-AR and Sim Avionics, has led many flight simulator enthusiasts to strive closer to Microsoft’s claim ‘as real as it gets’.

LEFT:  There is little mistaking the tell-tale white-coloured handles and skirts of the Next Generation Throttle. (click to enlarge).

The availability of real parts formally used in classic airframes has never been greater, and many enthusiasts are purchasing various parts and converting them to flight simulator use.

The ‘holy grail’ of conversion has always been the Boeing throttle unit, and depending upon individual requirements, many older style throttle units have been retrofitted to appear very similar, if not near-identical, to their Next Generation counterparts.

This article will compare and contrast the major differences between the Boeing 737 classic throttle and the Next Generation throttle.  The word classic is usually used to refer to airframes belonging to the 200, 300, 400 and 500 series.  The Next Generation (NG) refers to the Boeing 600, 700, 800 and 900 series.

Historical Context

The throttle quadrant observed in a modern airliner has relatively old roots. 

LEFT:  Boeing 727-100 throttle quadrant.  Although there are obvious differences in that the 727 has three engines, the overall design and appearance of the quadrant is very similar to its modern counterpart.  Image copyright to Keven Walchler (click to enlarge).

The forbearer of the NG throttle was designed in the late 50's and early 60's and was initially used in the B707.  As aircraft types evolved, throttle design remained relatively static with similar-designed throttles being used in the Boeing 727, 717 and 737 series aircraft.

The B737-100 made its debut in April 1968, to be followed shortly by the 200 series with a slightly longer fuselage.  During the 1980’s Boeing released the classic series of airframes from the 300 through to the 500 series. 

During this time, the technology altered little and the design of the throttle quadrant reflected the ability of Boeing to reuse existing technology with minimal alterations.  This principle of reuse can save a company millions of dollars in redesign and development costs.

This Goes With That (Compare and Contrast)

The Boeing 737-800 NG is the airframe that many enthusiasts strive to duplicate in a flight simulator.  However, Next Generation parts are difficult to find and when found are expensive to procure.  Fortunately, for the simulation community, a throttle unit will function correctly within flight simulator no matter what airframe the throttle originated.

Many of the nuances between a classic and NG throttle quadrant are subtle and for the most part only the more knowledgeable will notice.  

The more obvious highlights of the NG are the white-coloured thrust lever shrouds, TOGA button assembly, flaps arc, speedbrake lever knob, and the moulded white-coloured side panels and panniers.  Whilst it is possible to alter many of the attributes of a classic throttle to conform with those of an NG, not every part can be easily transformed.  For example, the flaps arc between the classic and NG is very different in design and appearance and cannot be retrofitted.

TABLE 1 provides an overview to the main visual differences between the classic and NG throttle quadrants (courtesy Karl Penrose who kindly allowed the use of photographs taken of his 600 series throttle).  Note that there may be other subtle differences, some visual and others in design/operation.  The table does not address the center pedestal as pedestals vary greatly between airframes.  Retrofit 1 refers to the level of difficulty it is to make the classic throttle appear similar to the NG unit.

1 The words 'level of difficulty' is subjective; it depends on numerous factors such as experience and knowledge – neither of which is identical between individuals.

Final Call

The differences between a classic and NG throttle unit are largely cosmetic with some subtle design and operational differences.  Retrofitting a classic unit to appear similar to a Next Generation throttle is possible, however, there will be some aesthetics that will probably not be altered, such as the speedbrake lever knob, stab trim indicator tabs, side mouldings, paniers and flaps arc.  

This said, the ability to use an OEM throttle unit, no matter from which airframe, far supersedes any reproduction unit on the market.  OEM throttles are sturdy, robust and well-built.  Unless you do something particularly foolish, you will not damage an OEM throttle.

BELOW:  Two image galleries showing the various differences between the classic and Next Generation throttle quadrants.  Thanks to Karl Penrose who kindly allowed the use of photographs taken of his 600 series throttle.  To stop the slideshow, click the image and navigate by the numbered squares beneath the image.

B737 Classic Series Throttle Quadrant


B737 Next Generation (NG) Series Throttle Quadrant