Trig 21 Transponder

This blog covers the installation of the Trig Model 21 Mode S transponder

Overview

While not mandatory for this aircraft to be fitted with a mode S transponder one became available from an aircraft upgrading at a good price - sold!

While complete it did not include the installation kit, so a Trig installation kit was purchased and placed in the cupboard until needed. 

At this point, it was noted that the plugs used push in crimp pins and the crimper was to cost $US100 plus delivered to Australia. My local radio guy advised me to just solder them with a very fine iron, not the first choice but my only one if I did not want to spend the money for 20 crimps plus a 2-week wait.

In a previous blog on wiring tools used on the project, the ferrules with crimper are shown but more importantly, it appeared to have the same action. A piece of 22 guage wire was inserted and a crimp applied, after a check, it was re-crimped providing adequate clamping force.

The other issue was all the builder had was a stock of 20 guage wire at this time - a little heavy but there. While as large as the pins allow, it did provide a solid crimp, while leaving some minor marks on the cable insulation.

Time to loom up.

Installation.
Followed the factory wiring diagram and installed the required cables, theses were labelled and the transponder clipped into its cradle located on the top side of the wheel well toward the panel.

The PPS sleeve is creating cool looking looms
The transponder clips into a lockable cradle

Comment
Get out of jail card played

Firewall Penterations

This blog covers the method used to create penetrations in the firewall. The purpose in the mind of this builder is a firewall has to keep not only heat but the gases produced by the engine compartment in normal and abnormal operations, i.e. a fire! 

Overview
Various options available; however, most were found to be bulky or just plain ugly.

This is expensive and bulky
especially a two dozen off.

An initial reckoning saw about a dozen penetrations required, and it occurred why not use an IP65 gland.

IP65 Enclosure - IP rated as "dust tight" and protected against water projected from a nozzle. To pass testing and achieve an IP65 rating, fixtures must be able to withstand water projected by a 0.25-inch nozzle.

It was decided to install these with the base facing to the firewall, then with the seal on the inside of the cockpit to provide the greatest degree of protection to the more vulnerable seals. The reasoning is by the time a fire begins to degrade the gland, that would be the least of your problems.

Too ugly for words

With the rear open located at the firewall side high-temperature, 3M 2000 silicon will be injected to fill the void, providing a fireproof ring.

As the gland body is manufactured from brass, nickel-plated, again by the time this fails, refer to comment in the paragraph above.

Not being flippant, but a light aircraft would be lucky to survive 5 minutes of a real fire because of a lack of fire suppression,  keeping the gases out should aid survival.

Installation
Simple, drill a 12 mm OD hole, disassemble gland, install on cable and then reassemble with the external nut treated with a low strength thread lock at assembly.

Nut, clamp/seal, mounting collar

Gland cluster starboard side - the opening around the cable
will be sealed with 3M 2000 silicon one all checks are completed

Comment
The weight is now my biggest issue, this is a function of the number of penetrations and assigning one cable to each to achieve the highest level of sealing.

Will it work, only fire would tell but compare it to other sports aircraft it will not be any worse.

Regulator

This blog covers the installation of the Silent Hektik Regulator.

Overview
The reason not to install a Rotax Regulator are covered in detail in a previous blog, and this will be just the nuts and bolts of the exercise.

Installation
The regulator had been fitted earlier, this is covered in a blog, but it was time to hardwire it into the aircraft.

Note: Heat conductive paste was applied before fixing to the S/S firewall, an air blast will be taken from the intercooler air inlet when fitted.

A problem was struck in while the manufacturer's instructions are precise, the wire sizes are not, except a vague mention of the use of 2.5 mm [14 guage] wire. The main reason would appear to be that the text was converted using a translator and some of the results make interesting reading. At this point, an email was sent to John at Dog Aviation, who kindly clarified what he had used in his RV12.

To summerize the wire used:

C  = 20 guage [Sence line]

L = 22 guage [Indicator light]

B - 12 guage [Battery]

R= 14 guage [Positive capiciator]

G = 10 guage [Feed from alternator]

All earths used are Black 14 / 12 guage, as required.

The diagram supplied by the manufacturer was followed precisely. Joe the L2 who is part of the team that will approve this aircraft pointed out generally are not fitted but reading the instructions, we interpreted it would be required with an injection system.

Our opinion is the capacitor may assist in removing ripple in the DC produced by the alternator but both of us agreed it would not hurt, and it's available.

The capacitor is 50V 33000 farad.

The final task was to mount the capacitor and it was decided to fabricate one from some scrap aluminium channel.

A piece of 25 x 12 x 1 extruded aluminium channel was drilled to lighten it and a modified work drive clamp to retain the capacitor. 

The assembly was fixed to the firewall with two [2] 3.2 mm pop rivets then the edges lined with 10 mm U channel rubber to protect the capacitor.

Note: doing it again the builder would look at milling a slot in the side of the channel and installing a lighter clamp

Comment
The final result was a tidy install showing the clear intent of the wiring

Time for a Snoopy.

Camouflage Colours

This blogs cover the colour selection for the aircraft.

Overview
The scheme selected was the RAF display scheme for 2010 developed to celebrate the 70th anniversary of the Battle of Britain.

However, over time it was decided to change the unit it to represent a fallen Australian pilot. Looking for a suitable ace, I was taken by all the nobody's, by this I mean those who paid the ultimate price but were not aces, just casualties in a brutal campaign.

They seem to share a common theme, trying to live a life in the 64 hours that the situation they were in granted them to live. In the end, I settled on a Flight Sargent  Frank W Cale.

These men achieved a victory that ensured our democracy's lived on, they forever do not need names, they will always be "The Few" -  Lest we forget

Paint Scheme
The first task was to pick the colours, and after a lot of research BS450 Dark Earth, BS241 Dark Green and BS216 Eau de Nil [Duck Egg Green] was the most likely scheme worn in 1940 by Cales Spitfire.  The spinner will be painted Satin Black as will the top of the cowl.

The colours will be matched to a set produced by Vallejo for the model aircraft market.

Frank W Cale Spitfire Mk1 KIA 15th August 1940

It has been decided to reduce the amount of the advanced warning notices and paint as close as practical to a 1940 paint scheme.

Mock up of the final paint scheme

Comment
It good to dream

Stick Grip

This blog covers the details of the installation of the stick grips.

Overview
This aircraft has to have a military-style stick grip, and the only choice was the Infinity grips, luckily a pair was purchased locally new but unused at a reasonable price.

Infinity Grip

It was decided to integrate some of the features by RS warbirds in the USA. One of the details was the ring below the grip - yellow ring in the image and was machined from ABS plastic.

Very tidy upgrade - RS Warbirds

The final location was determined, this involved reducing the length of the shaft at the stick mounting to lower the grip. Once satisfied, the collar was secured in position using a single black 1/8 x 6 mm pop rivet.

The cables were wrapped in a PPS tube, run through the control stick and out using a slot cut in the tube before installation.

Cable staged - yet to be soldered to switches

The cables were now run and secured to the airframe will all control sticks terminating at the junction box located on the starboard side of the pilot's cockpit. Both sticks end in this box with the pilot able to control flaps, boost pump, transponder ident, trims, and mike. The co-pilot lacks the transponder control.

Junction box.

The grip was secured at a slight angle, it was noted that when the grips were tightened, they were loose, so the area above the collar was wrapped in one layer of gaffer tape that was folded into the tube providing a rudimentary anti-chafe for the wires.

Comment
Done.

Undercarriage Panel

This blog covers the fuel pump panel.

Overview
The styling selected for the aircraft meant that the controls are installed in groups, this means that the undercarriage panel the control, power, hydraulic pressure gauge and indicator lights are fitted into one panel.

Installation.
A facia panel was designed to accommodate the schematic and all material used was 2024-T3 aluminium alodined after fabrication. 

The panel has a single AMP four [4] pin terminal featuring gold plated contacts and a robust lock. This fits into an aluminium bracket that is fixed to the facia using automotive trim tape to the facia and has proved remarkably robust. The 1 1/4'' UMA instruments are fitted with 9 pin RS232 plugs allowing disconnection.

The use of plus is critical to allow removal of the panel with all instruments and is one of the design criteria. 

The panel is fitted with hydraulic pressure, control and power to the pump with all lights featuring a press to test facility.

The panel is fitted with a series of plugs to allow removal. A four [4] pin AMP plug allow power and earth to be brought into the panel. The two [4] pin RS 232 plug is a special item rated at 30 plus amps and has gold plated contacts with the UMA instrument featuring a nine [9] pin RS 232 plug. All these plugs allow the removal of the panel as a single unit for servicing.

Comments

Finished as envisaged.

Completed and ready for service with the last task to fit the graphic label to the face of the panel.

Fuel Pump Panel

This blog covers the fuel pump panel.

Overview
The styling selected for the aircraft meant that the controls are installed in groups and means that for the fuel panel the control, power, guages and indicator lights are fitted into one panel.

Installation.
A facia panel was designed to accommodate the schematic and all material used was 2024-T3 aluminium alodined after fabrication. 

The panel has a single AMP four [4] pin terminal featuring gold plated contacts and a robust lock. This fits into an aluminium bracket that is fixed to the facia using automotive trim tape to the facia and has proved remarkably robust. The 1 1/4'' UMA instruments are fitted with 9 pin RS232 plugs allowing disconnection.

The use of plus is critical to allow removal of the panel with all instruments and is one of the design criteria. 

Instruments are secured using #6-32 brass instrument screws.

The inter-wiring reduced the number of power/earth wires

Comments
Finished as envisaged.

Completed and ready for service with the last task to fit the graphic label to the face of the panel.

CO Detector

This blog covers the installation of the CO detector

Overview
To operate in Australia all aircraft must have some means of detecting the presence of Carbon Monoxide, this can be as simple as a card to an integrated detector.

A Guardian Avionics Carbon Monoxide Model 452 was selected based on its size of cost, however, in small panel present in a tandem aircraft there was no space. Luckily as the goal is to create a military cockpit, so a tack on box works.

Installation.
A plastic box was selected and the top cut to allow the detector to be installed. Next, a circuit breaker had to be installed in line with the design philosophy of the cockpit. Simply this means all devices associated with the operation of a distinct system are grouped.

The box was sprayed with plastic adhesion primer and one coat of Satin Black Spray Acrylic to blend with the cockpit colour and remove the plastic look.

Box interior - tight

The original choice of Klixion circuit breakers paid dividends because of there small size.

Front of box
Note: 20 amp was used to allow assembly
while waiting for the correct breaker

A surplus UMA 9 pin RS232 plug was used as it allows the pins to be crimped rather than being soldered, again this was an advantage in the small area available in the box. Power wires were added to the plug, loomed with the PPS tube and sealed with dual wall adhesive heat shrink.

CO detector mounted in final position

A series of M3 rivet nuts were installed in the end wall of the wheel well to secure the box to the airframe. The box was secured with four [4] M3 x 12 S/S pan head screws.

Both wires were now terminated to the general bus.

Comments
Done.