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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 B737 Flight Simulator (93)

Sunday
Apr292018

ISFD Knob Fabricated

The Integrated Standby Flight Display (ISFD) is mounted in the stand-by instrument cluster in the Main Instrument Panel (MIP).  The ISFD provides redundancy should the Primary Flight Display (PFD) on the Captain or First Officer fail. 

LEFT:  OEM ISFD (Image copyright Driven Technologies INC).

The ISFD is not a common panel to find second hand, and working units are expensive to purchase.  I don't  have an OEM ISFD, but rather (at least for the moment) use a working virtual image displayed by ProSim737. 

Conversion of an OEM unit is possible, however, the unit would need to be fully operational, and  finding a working unit at a reasonable price is unlikely.  ISFDs are expensive and reuse is common.  If a unit does not meet certification standard, it's disposed of because it's broken and cannot be economically repaired.

ISFD Knob

LEFT:  ISFD knob.  Two versions: one replicates the taller NG style while the other is slightly shorter.  Although not functional, they provide a better representation of the plastic knob that previously was installed.  (Click to enlarge).

The ISFD knob that came bundled with the MIP I purchased is very mediocre in appearance – in fact it's a piece of plastic that barely looks like a realistic knob.  I purposely have not included an image, as the design would be an embarrassment to the company that produced the MIP.

LEFT: Knob being fabricated on a lathe.  This photograph has been taken by another person and is not my property (click to enlarge).

A friend of mine is a bit of a wizard in making weird things, so I asked him if he could make a knob for me.  He made two knobs – one based on the standard design seen in the Next Generation airframe and the other knob a shorter version of the same type. 

Attention to Detail

Attention to detail is important and each knob has the small grub screw and cross hatch design as seen on the OEM knob.  The knobs have been made from aluminum and will be primed and painted the correct colour in the near future.

A 2 axis CNC lathe was used to fabricate the knobs.  The use of a computerised lathe enables the measurements of a real knob to be accurately duplicated, in additiona to any specoifc design (such as cross hatching or holes to install grub screws).

Thursday
Feb012018

Variation in Panel Colour, Manufacture & Location - Center Pedestal

The center pedestal in the Boeing 737 accommodates a number of panels, several of which are standard for all commercial passenger airlines.  All high-end simulators replicate these panels and enthusiasts often fixate on several issues.  Namely:

(i)         The colour of the panel and lightplate;

(ii)        The position of the panel in the center pedestal;

(iii)       The backlighting of the lightplate (bulbs verses LEDs);

(iv)       The manufacturer of the panel, and;

(v)        The aesthetic condition of the lightplate.

Although seemingly important to a cockpit builder, to the casual observe, or indeed to many pilots, these attributes are of little consequence.  Nevertheless, it's understandable why many believe all the panels are identical in all B737 airframes.

Whilst it's true that all airlines must meet aviation standards for the type of operation they fly, the panel manufacturer and where in the pedestal the panel is located is at the discretion of the airline.  Furthermore, it's not uncommon to observe older style panels mixed with modern panels and to see lightplates that are illuminated by bulbs and LEDs side by side.

Note that some of this information probably pertains more to older Next Generation 737s than to the latest airframe build released from Boeing.  I use the word 'panel' to denote an avionics module.

Colour of Lightplates

The official colour shade used by Boeing is Federal Standard 5956 36440 (light gull grey).  However, OEM part manufacturers may use slightly different colour hues.  For example, IPECO use British Standard 381C-632 (dark admiralty grey) and Gables use RAL 7011.  This said, often an airline will 'touch up' a lightplate that is damaged or faded - this introduces a further colour variant. 

LEFT:  Air Alaska 737-700 pedestal.  Note higher than standard position of ACP panels and relocated position of the door lock panel.  Also high mounted position of rudder trim panel (click to enlarge).

As an example, a lightplate I repaired from a B737-500 airframe revealed three differing shades of grey beneath the final top coat of paint.  This is not to mention that, depending on the manufacturer of the lightplate, the final coat of paint may be matt, semi-matt or gloss.

From the perspective of an engineer, the colour (and to a certain extent aesthetic  condition) is unimportant when replacing a defective part with another.  Time spent in the hanger equates to a loss in revenue by the airline.  Therefore turn-around times are as brief as possible and keeping an aircraft on the ground while procuring the correct shade of Boeing grey does not enter the equation.

Position of Panels in the Center Pedestal

Boeing recommends a more or less standard position for the essential panels in the center pedestal (NAV, COM, ADF, ASP, rudder trim, door lock and panel flood), however, the location of the panels is often altered by the receiving airline, and is to a certain extent is determined by what other panels are installed to the pedestal.  Areas (holes) in the pedestal not used by a panel are covered over with a grey-coloured metal blank.

LEFT:  This photograph of the center pedestal of a Boeing 737-500 was taken in 2016.  The aircraft is a freighter used to transport parcels that has been converted from a passenger aircraft.  Apart from the older style ACP panels, note the disparate displays between the NAV and COM radios.  Also note the position of the ADF radios and some of the other panels; they do not conform to what is usually thought of as a standard set-out.  Finally, note the scratches on the pedestal and on some of the panels and lightplates - they hardly look new (click to enlarge).

Panels are manufactured by several companies, and often there appearance will differ slightly between manufacturer, although the panel's functionality will be identical.  The airline more often than not chooses which panel is used, and often the decision is biased by the cost of the panel.  Therefore, it's not uncommon to observe several airframes of a similar age with differing panels positioned in different areas of the center pedestal.

Panel Condition

Enthusiasts pride themselves in having a simulator that looks brand new.  However, in the real world a Level D simulator or flight deck rarely looks new after entering service.  Panels can be soiled and paint is chipped and scratched, and depending on age, some lightplates are faded to due to the high UV environment that is present in a flight deck.

So where am I going with this?  Enthusiasts strive to match their panels with those observed in a real airliner, however, more often than not this information comes from photographs distributed by Boeing Corporation (which nearly always depict panels in a standard position in the center pedestal). 

The variables noted by enthusiasts should not cause consternation, as real aircraft show similar variation.  Remember that in the real aircraft, colour, manufacturer, and to a certain extent aesthetic condition is not important - functionality is.

To see additional photographs, navigate to the image portal.

Friday
Aug042017

Conversion of OEM CDU - Using SimStack Hardware and Software

This article follows on from an earlier post that introduced the concept of converting an OEM CDU to use in flight simulator.  The conversion has now been completed and the CDU operates seamlessly with ProSim-AR.   

LEFT:  OEM CDU fully converted and operational.  The CDU is from a classic 500 series aircraft.  Prior to my ownership, the CDU was used by United Airlines (click to enlarge)

Historical Conversion Techniques

To date, various OEM parts have been converted using Phidget cards, and to a lesser extent Leo Bodnar cards, Flight Deck Solutions system cards, and PoKeys interface cards.  Phidgets provide a stable platform, despite the disadvantage that they, at time of writing, only connect via USB to the server computer.  The primary advantage of using Phidgets is that they have been used in a wide variety of applications, are inherently stable (for the most part), and their configuration is well documented.

The conversion of the CDU was slightly different to the norm, in that a different interface system was used. 

SimStack Software by Simulator Solutions

The conversion of the CDU was done in collaboration with Sydney-based company Simulator Solutions Pty Ltd.  Simulator Solutions utilise their propriety interface boards called SimStack to convert OEM parts for use in commercial-grade simulators

SimStack is a modular, stackable, and scalable hardware interface that is designed to integrate various replica and OEM parts into your simulator.  The SimStack Foundation Board (SFB) forms the backbone of the SimStack system, and to this interface board a number of other propriety boards can easily be piggy-backed.  One of the many advantages in using SimStack hardware and software is that the interface can connect with either the server or client computer via Ethernet (as opposed to Phidgets, which at the time of writing, only connects using USB). 

To date, Simulator Solution’s experience has been predominately with the conversion of B747 parts and Rodney and John (owners) were excited to have the opportunity to evaluate their software on the 737 platform, with the 737 CDU being the ‘first cab off the rank’.  A future use of SimStack, using a SimStack ARINC 429 board connected with a foundation board, will be the conversion of an OEM flaps gauge.

This article is introductory, will not delve deeply into the SimStack architecture, nor will it document the wire pin-outs used with the interface card; a future post will tackle this topic in more detail. 

OEM Conversion - Choose Your Poison

There are two main camps when discussing how to convert an OEM part.  The first is to utilise as much of the original wiring and parts as possible.  The second is to completely ‘gut’ the part and convert it cleanly using an interface that connects seamlessly with the avionics software in use (ProSim-AR).  A third option, although expensive, is to use ARINC 429.  The advantage of using ARINC 429 is seamless connection of the part to the simulator software using the original wiring and Canon connectors.

With regard to the CDU, the easiest route was option two; everything in the CDU was removed with the exception of the internal shelf divider and keypad.  In hindsight, the pin-outs of the male Canon plugs could have been used.  However, this would have required the purchase of a female male Canon plug, or the fabrication of a reproduction plug.  For the use of a couple of pins, this seemed to be overkill.

Keypad and Screen

The keypad and screen are the two most important parts of the CDU, and it's vital that the connection between the keypad, screen, and the SimStacks Foundation Board is not compromised.  The actual functionality of the CDU is controlled by the avionics suite.

Keypad

The keypad forms part of the lightplate in which 5 Volt incandescent bulbs are strategically located to ensure even backlighting of the keys.  Disassembling and removing the keypad from the main body of the CDU is straightforward; several small Philips head screws hold the keypad in place.  Once the keypad has been removed, any ‘blown’ bulbs can be replaced. 

Table 1: Overview of bulb location, part number and quantity.

The keypad has several wires that connect to a terminus inside the main body of the CDU.  Care must be taken when cutting the strands of wire to ensure the connection between the terminus and the keypad is not damaged.  Depending upon your skill, the terminus can be removed and a longer wire soldered to the keypad connector, or the wire can be lengthened (by splicing).  The wires from the terminus connect with the SimStack Foundation Board.

CRT and LCD Screen

The Classic CDU is fitted with a solid glass cathode ray tube (CRT) screen.  The CRT screen is approximately 2 cm thick and fits snugly within the display frame of the CDU. 

LEFT:  The CRT screen forms part of the CDU casing.  The silver coloured foil indicates the thickness of the replacement glass that needed to be ground (click to enlarge).

It’s possible to make the CRT screen operational, however,  the display would be monochromatic (green) and the screen resolution poor.  Therefore, the CRT was replaced with a custom-sized high resolution colour LCD screen.

To retrofit a replacement screen is not without its challenges.  The LCD screen is not as thick as the CRT screen, and is also not the same shape.  Therefore, the screen will not fit snugly within the display recess.  To rectify this shortfall, a piece of clear glass was ground to correctly fit within the display frame of the CDU.  This piece of glass replaces the 2 cm thick CRT glass.  The thin LCD screen was then mounted behind the clear glass in a central position.

During the design phase, it was thought that the thick piece of glass would cause a refraction problem.  However, although the theory suggests refraction will occur, the practical application has been such that any refraction is not readily noticeable.

Mounting the LCD Screen

Mounting the LCD screen can be done a number of ways.  Commercial grade double-sided sticky tape is the easiest method, but it is rudimentary.

LEFT:  LCD screen is fitted and temporarily held in position by commercial tape and a foam spacer.  Prior to revamping the CDU, this area was used to house the very large square shaped CRT screen.  Note the ribbon cable linking the screen to the screen interface card and the two white cables that connect to the screen controller card and SFB (click to enlarge).

To secure the LCD so that the screen sat firmly against the glass, thin metal plate was used to replace the open space that was left after removal of the CRT screen.  The sides of the metal plate were fabricated to push against the rear edge of the LCD.  This firmly secured the LCD screen against the rear of the clear glass.

LEFT:  The photograph shows the metal plate that was fabricated to replace the CRT screen (which roughly took up 5 inches square in space).  The edge of the plate secures the LCD screen against the glass.  To remove the metal plate cover to access the LCD screen, 2 screws need to be removed.  (click to enlarge).

Although the use of metal plate appears slightly unattractive, the plate only serves to enclose the CDU.  Once the CDU is slid into the CDU bay, the the casing of the CDU is not visible.

An alterative to using metal plate is to use ABS plastic painted the correct Boeing grey colour.

SimStack Foundation Board, Screen Controller Card and Wiring

To ensure that the CDU is standalone and will function without external inputs other than power supplies, four items need to be mounted inside the CDU.

(i)     A generic interface card that controls the LCD screen;

(ii)    A LCD screen controller board (buttons that control screen brightness, contrast, etc);

(iii)   A SimStack Foundation Board; and,

(iv)   The wiring to connect the CDU keyboard to the SimStack Foundation Board.

Fortunately, there is ample room in the cavernous interior of the CDU to fit these items.

LEFT:  SimStack Foundation Board (SFB) mounted into the lower section of the CDU casing.  The SFB is responsible  for registering the key presses made on the keypad which are then deciphered and communicated to the avionics suite (ProSim-AR).  Click to enlarge.

The SimStack Foundation Board is mounted on an angular metal bracket that is attached directly to the bottom of the CDU, while the LCD interface card has been installed on the upper shelf along with the screen controller.  A ribbon cable connects the LCD screen to the interface card while a standard VGA cable connects the LCD screen to the client computer. 

The SimStack Foundation Board is Ethernet ready and requires a standard Ethernet cable (CAT 6) to connect from the card to an Ethernet switch (located behind the MIP). 

In addition to the Ethernet  and VGA cable, six power wires leave the CDU via the rear of the casing; four from the SimStack Foundation Board (5 and 12 volts +-) and two from the keypad (5 volts +-) to control the backlighting.

Toggle Switch

A standard two-way toggle switch is mounted to the rear of the CDU casing.  This switch is used to control whether the LCD screen, used in the CDU, is always on, or is only turned on when ProSim-AR is activated.  The switch is set and forget, however, access to the switch is possible by sliding the CDU slightly out of the CDU bay.

 

LEFT:  Toggle switch and wire harness leaving the base of the CDU casing.  The switch position and harness use the existing holes in the casing that were previously used by the Canon plugs.  5 and 12 volt wires are connected to appropriate busbars behind the MIP, while the VGA cable connects with the client computer.  The Ethernet cable connects into the Ethernet switch, also mounted at the front of the MIP (click to enlarge).

Power Supply

To operate the CDU requires a 5 and 12 volt power supply.  The backlighting of the keypad is powered by 5 volts while the SimStack Foundation Board and CDU operation require 12 volts.  Connection of the wires is to a busbar that connects to the respective power supples.

Backlight Dimming

On my set-up, to enable the CDU keyboard to be dimmed, the 5 volt wires that leave the lower section of the CDU, are connected to a dedicated 5 volt Busbar located in the center pedestal.  This Busbar is used to connect the backlighting from all OEM panels.  The Busbar is then connected to the panel knob on the center pedestal.  To turn the backlighting on and off is controlled by opening or closing a 12 volt relay (attached in line between the panel knob and Busbar).  Dimming is controlled by a dimmer circuit.

Mounting the CDU to Flight Deck Solutions MIP

The MIP (which in my set-up is a skeleton on which to mount OEM parts) and CDU bay is manufactured by Flight Deck Solutions (FDS), and is designed to fit FDS’s propriety CDU unit (MX Pro) and not an OEM unit.

The casing for the OEM CDU is much longer than the FDS CDU and measures 24 cm in length.  This must be taken into account if intending to install an OEM CDU to an FDS MIP.

The FDS MIP incorporates an aluminum shelf (used by FDS to mount various interface cards) that protrudes slightly into the CDU bay.  This protrusion stops the OEM casing from sliding all the way into the bay.  To enable the CDU casing to slide fully into the bay, a small section of the shelf must be cut away.

A small metal saw is used to trim the metal away from the shelf, and although an easy task, care must be taken not to ‘saw away’ too much metal.  Once the piece of offending aluminum is removed, the casing of the CDU slides perfectly into the bay, to be secured by the DZUS fasteners to the DZUS rail.

LEFT:  Using a small metal saw, s small section of the shelf is removed.  This enables the CDU to slide into the CDU bay.  Left image is the shelf projecting into the CDU bay while the right image shows the shelf removed and covered in protective tape (to minimise abrasion).  A small notch was made at the corner to facilitate the safe routing of the wires used to enable the Lights Test (click to enlarge).

Functionality and Operation

The CDU is not intelligent; it’s basically a glorified keyboard that requires interfacing with software for functionality.  The functionality, fonts, colour, etc are provided by the avionics suite (in this case ProSim-AR, but arguably it could also be Sim Avionics or Project Magenta). 

To enable communication between the avionics suite and the SimStack Foundation Board (in the CDU casing), SimStack proprietary software must be installed.

SimStack Software - SimSwitch

SimSwitch is installed on the client computer and when configured interfaces with ProSim-AR on the server computer and the network.  Configuring SimSwitch is straightforward and involves inputting the correct static IP address and port numbers.

LEFT:  Screen grab showing SimSwitch software interface.  This is located on the client computer.  The interface, once configured, is standalone.  The software can easily be opened in minimized mode via a batch file (click to enlarge).

SimSwitch can also be used to monitor all connected OEM panels and provide debugging information if needed.

SimSwitch is a JAR archive executable file.  The file must be in operation to eanable the CDU to communicate with the avionics suite. 

The JAR file and the ProSim CDU .exe file must both be open for the CDU to function correctly.  To expedite a simulator session, the JAR file can very easily be added to a batch file for automatic loading of software prior to a simulator session.  A timer command can be added to the batch file line ensuring the JAR file opens before the ProSim CDU.exe file. 

Independent Operation

The Captain and First Officer CDUs are not cloned (although this is easy to do), but operate as separate units.  This is identical to the operation in the real aircraft, whereby the Captain and First Officer are responsible for specific tasks when inputting the information into the CDU.

First Officer CDU

The First Officer CDU will be converted using a similar technique, with the exception that this unit will be converted more ‘cleanly’

(i)    A dedicated plate (rather than an angular bracket) will be fitted to the inside of the CDU casing.  This will facilitate the mounting of the SimStacks Foundation Board;

(ii)    The LCD screen controller card will be fitted to the rear of the screen;

(iii)    The LCD screen will be fitted to customised bracket making installation easier; and,

(iv)    The Ethernet cable connector will located outside the casing.  This will provide easier access and also enable less of a tight fit when reassembling the casing.

Following on, the Captain CDU will be revamped to take into account the improvements made to the First Officer unit.

Additional Photographs and Video

Additional photographs can be viewed in the image gallery.

BELOW: A short video demonstrating the operation of the OEM CDU using ProSim-AR. 

Main points to note in the video are:

(i)    Heavy duty tactile keys;

(ii)   The definite click that is heard when depressing a key;

(iii)  The solid keypad (the keys do not wobble about in their sockets); and,

(iv) Although subjective, the appearance of the OEM CDU looks more aesthetically pleasing that a reproduction unit.

Final Call

This conversion, by using a SimStack Foundation Board (SFB), has enabled full functionality of the OEM CDU using ProSim-AR.  The SFB can also be used to connect with other avionics suites, such as Sim Avionics and Project Magenta.  However, although the wiring of the SFB would be identical, the way in which the card interfaces and communicates with the avionics suite will differ.

Glossary

ARINC429 –  A standard used to  address data communications between avionics components.  The most widely used  standard is an avionics data bus.  ARINC 429 enables a single transmitter to communicate data to up to 20 receivers over a single bus.

SFB - SimStack Foundation Board.

Standalone – Two meanings.  (i)   Operation does not require an interface card to be mounted outside of the panel/part; and, (ii)  In relation to software, the executable file (.exe) does not need to be installed to C Drive, but can be executed from any folder or the desktop.

Friday
Feb102017

Troubleshooting Power Management Settings and Solving USB Disconnects 

Remember when all that was required to run flight simulator was one display monitor, joystick and a keyboard – those days are long gone.   

LEFT:  High-speed 5 volt powered USB hub.  This hub resides in the Throttle Interface Module (TIM).  Note ferrite choke. (click to enlarge).

Depending upon the level of system complexity, a flight simulator may require a dozen or more ports to connect peripheral items to a server or client computer (s).  Historically, connection of peripherals has been via USB.  

USB is an acronym for Universal Serial Bus and, generally speaking, if only a few peripherals are attached to a computer, there usually is not a problem with communication between the computer and the attached device.  However, as interface cards and peripherals become more complicated and numerous, there is a propensity for disconnects to occur more frequently.  A USB disconnect usually announces itself by the sound card playing the ‘ding-dong’ sound as the peripheral disconnects itself from the computer.

Guidelines (golden rules)

There are several ‘golden rules’ to remember when using USB.

(i)      Try and keep all USB cables as short as possible;
(ii)     Do not join USB cables together;
(iii)    Always use quality USB cables with quality connectors;
(iv)    Do not ‘kink’ the USB cable or wrap the cable so tightly that the wires are at a 90-degree angle;
(v)     Do not lie USB cables beside one another so they are touching, but maintain some space between them;
(vi)     Use a USB cable fitted with noise limiting nodes (NLN);
(vii)    Use a USB cable/port that is rated at the highest output (USB 3 or above); and,
(viii)   Where possible for multi USB connections use a quality powered USB hub.

Noise Limiting Node (NLN)

A noise limiting node (NLN), also known as a 'ferrite choke' is a small cylindrical node that sits at each end of a USB cable.  Briefly explained the nodes are made from a solid ball of ferrite which is magnetic and therefore quite heavy.

LEFT:  Ferrite choke on USB cable.

The purpose of the NLN is to stop electromagnetic interference (EMI) transferring from the peripheral to the computer.  EMI can be produced from any number of peripheral items and a USB cable running between the peripheral and the computer acts as an antenna, picking up and transmitting EMI current.  The current can, but not necessarily always, cause havoc with either the operation of the peripheral or the computer itself.  

Adding USB Ports

As the number of add-on peripherals increase, the number of available ports falls short and additional USB ports need to be added to the computer.  Additional ports can easily be added to a computer via a PCE card which enables (on average) an additional 4 USB ports to be added to your computer.  A PCI card is attached to your motherboard.

Power Requirements

One of the main reasons that USB disconnects occur, relates to the power that is available to the computer’s USB port.  Often the power requirements of the device will be greater than that provided to the USB port; this causes a disconnect.  Additionally, depending upon your computer, it is not uncommon for power to fluctuate between USB ports as the computer’s motherboard directs power to various processes.

Depending upon how your system is set-up, when several devices 'come on line' a minor spike can be generated.  Often, this spike can momentarily exceed the amperage rating of the USB port.  This can cause a disconnect to occur.

It’s important to understand that not all USB ports are made identical.  In general, the ports on the rear of the computer are part of the computer’s motherboard; these ports are rated as high power ports.  However, USB ports that are not part of the motherboard, and usually located on the front of the computer may not receive the same power rating.  

Often a supply company will provide a computer will a dozen or so USB ports, however, to save money will choose to use what is called a ‘front panel USB header’ which has a small piece of circuitry that acts as a hub.  In this case, the power to the front panel USB is reduced.  Furthermore, it is probable that these ports may not be USB 3 and if used for a high-demand peripheral will cause a disconnects to occur.

USB Hubs

Another strong recommendation is to use a high quality powered USB hub rather than connecting several USB cables directly to a computer.  A powered hub should be used rather than an unpowered hub as the former provides its own direct power source which is usually rated at a higher amperage than the computer’s USB port.  

The interface modules that form the core of my simulation system have one or two powered hubs installed to the module.  The interface cards are then connected by very short USB cables to the hub.  A high quality USB cable (with a NLN) then connects the interface module directly to the computer.

Windows Power Management Settings (PMS)

Not all USB peripherals will be required at all times.  Often a device will not need to communicate with the computer until something is required – such as a change to a radio frequency, an input from the control column or a key press to the MCP or CDU.

LEFT:  Screen grab of Windows 7 PMS (click to enlarge).

Windows has a nasty habit of ‘putting to sleep’ a USB connection that is not being used.  It does this to save power.  It is very imperative that you ensure that all power saving modes are turned off with regard to USB.  

To do this open your control panel and search for device manager.  Scroll down until you find Universal Serial Bus.  Under this tab you will find all the USB ports that you have attached to your computer.  Open each in turn and check the power management settings and ensure they are turned off.

Troubleshooting USB Disconnects

It is paramount to try and discover which peripheral is causing the disconnect.  The easiest way to troubleshoot a disconnect issue is to remove ALL the USB cables from the computer, and then one by one re-connect the cables to the allocated port and test.  Make sure you switch your computer off and on as you add each of the cables in turn.  Hopefully, you will eventually discover which cable/device is causing the issue.  The problem device will ‘ding dong’ if a secure connection is not possible.

If USB disconnects continue, try swapping the cables between different USB ports on the computer.  The disconnect issue maybe caused by the USB port/cable combination you are using.  As mentioned, not all USB ports have the same amount of power/amps available to them. 

Try to place peripherals that require minimal power, such as a mouse or keyboard, on lower-powered USB ports, and place more energy-requiring peripherals on powered hubs; perhaps only a few devices on the one hub.  Doing this will ensure that the hub will always have enough power (amps) to power the devices attached (cancelling out possible spikes as discussed above).  

Final Call

Hopefully, if you apply the above-mentioned suggestions USB disconnects will cease.  However, you will eventually reach the limit of USB capability, and at this point the use of Ethernet should be investigated to augment, or to replace the reliance on USB.

This article is but a primer.  I am not an IT expert and welcome any comments.

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).