Elevator Stab - Part 1

Wings & Elevator's as delivered

The elevator stab is supplied with a factory assembled frame. All the skins are held on by a series of temporary rivets. These were drilled out allowing the panels to be removed to be prepared for re-installation.

The spars were pre-drilled at the factory for the captive nuts but the the hole's for the rivets and countersinks were prepared by the builder with the other task to dimple the factory pre-drilled nose skin's.

Typical attachments

The frame was fitted to a mounting frame and bolted firmly at one end and lightly to allow float at the other preventing distortion begin introduced. 

The skins were all clecoed back onto the frame. It was found that the nose had to be left only held with a few safety clecos to allow the back's to be re-installed. 

All holes were clecoed to ensure the assembly was exactly as it was when pre-drilled at the factory.

Trial fitting skins for riveting

With the back sheets on the nose was clecoed and a final inspection made. The only task left was to remove the clecos one at a time and fill the hole with either a dome or counter sunk rivets are required. 

The only holes not riveted were for the end fairings. 

More details in part 2

Mounting Frame
The assembly frame was manufactured from a standard hollow core door and was chosen as it is flat and machined all round. This provide's a flat and square face to fit 75 x 25 DAR pine creating a long narrow mount. Two blocks off 50 x 50 DAR pine were used to pack the rear of the elevator spar all allow both skins to be fitted [not shown].

When finished it will be used to provide a strong, torsional ridged and flat surface to assemble the elevators on. 

Rudder Faring Bottom - Part 4

The D-nose was riveted to the spar at this time but the taper created by the assembly technique for the D-Nose was discovered at the first trail fitting of the bottom faring. If correctly shaped it would have fitted as neatly as the top fairing. 

Options: The first choice was to install it as is but the rudder would have looked like it was bashed with an ugly stick. The other was to modify to achieve the best fit bearing in mind that ongoing modification is the bastard child of change but change it had to be.

Faring Attachment
The start was to install the faring attachment with it running the perimeter of the rudder. This was fabricated from 0.012"" x 2024-T3 to provide addition stiffness. It was installed using the same techniques outlined in the blog on the top faring - click here


To maintain the support at the D-Nose meant that the rudder cable mounting plate would have to be modified. It was decided to move the front edge back to create two horns for the cable to attach too at each side. The front of the faring attachment was pin drilled and file-ed to create a slot for the horns to project through.

Rudder Attachment

Horn attachment

The bracket supplied had three [3] mounting holes at the rear and one at the front however the mounting required the attachment to sit on the two [2] pop rivets securing the lower rib to the spar. 

It was decided to duplicate the mounting holes onto the rudder attachment. A piece of paper was attached to the lower rib and the two rivet heads located. This pattern was then transferred to the rudder attachment and new holes added. These holes were enlarged to 4 mm to ensure a accuracy at the point of attachment. 

The horn was inserted then pop riveted as shown with the front attachment requiring a 5 mm pop rivet [not supplied with kit]

Marking rudder attachment

Capturing Centers

Finished faring and rudder attachment

Note: The faring strip was created in separate components with the joint at the rear. This was not a good idea as it made fitting of the faring difficult as it caught on assembly. It would be better located at the front. 

Faring Installation
The faring was slotted using a 5/32'' chain file as shown to create additional flexibility necessary to align the front edge to the faring attachment. It will be fixed with 1/8'' pop rivets at the front as required to hold the front flange in the correct location. The faring will be fixed as described in the blog on the top faring installation - click here

At the time of installation the slots will be covered with 100 mm wide self adhesive tape.

Lower faring final fit-up
Note: Drain hole located at the base to prevent water buildup

Rudder Faring Top - Part 3

The kit is supplied with two fiberglass faring to for the top and bottom of the rudder. 

Top Faring Installation

Scribe Line

The top faring has to be trimmed to the correct overall height. The factory has marked this with a scribed line on the outside of the skin. This should be filled either with a pencil or felt pen to make it clearer when sanding. The faring was initially sanded on a disc sander until it was about 1.5 mm from the scribed line. 

Top Faring Sanding

It was next placed on a flat surface on a sheet of 80 grit aluminium open cut paper and hand sanded to the line. The final adjustment's were made using 80 grit aluminium cut paper wrapped about a 50 x 25 DAR piece of pine.

Fitting

Marking jig

Trail fitting of the faring showed no issues when installed over the aluminum strips installed previously for this purpose. The faring was taped into position to secure it into it's correct location.

The holes for mounting were pitched at 60 mm using the existing rivets as a guide. Locations were then transferred using a small aluminum jig with a reference line marked with a square. 

It was placed on a rivet center and its center transferred to the faring. The correct location for the horizontal was also transferred to the faring at each location.


The faring was removed and the marked holes drilled 9/64'' and the faring re-installed. The locations were marked with a felt pen and the faring removed to allow the holes to be drilled with a 1/8'' drill. The faring was re-installed and fully clecoed and fixed with 1/8'' pop rivets. 

Note: The holes in the fiberglass were drilled oversize to try reduce pressure slightly when begin riveted.

Fitted and ready to rivet

Rudder Mass Balance - Part 2

Before modification- nose
rib inverted

When the D-Nose was inspected, it was noted that the lower rib was close to the base of the hinge which could have made bolting difficult later. It was decided to invert these at the top and bottom to create more space.

This had a unforeseen benefit when it came time to rivet these to the D-nose as they can now all be supported by hand when drilling as the ribs flanges have a tendency to move away from the drill.

The aluminium faring attachments should be installed at this time.

Mass Balance Skin
The factory skin was formed to a included angle of 80 - 90 deg. about the panel center on a 30 mm OD mandrel [aka the broom handle] putting the initial form into the skin, then hand massaged to suit by rubbing around the edge of the plastic table. The skin was then held in position with both ends placed under the rudder skin and taped into a fixed location.

The first hole was matched drilled and clecoed then inverted and repeated at the opposite side. After a check all top rib holes were marked and drilled after removing the skin. 


The M10 threaded rod was installed with an aluminium tube [scrap fuel tube] to set the correct spacing and secured with an M10 nut. As the flange of the threaded bush is located on the base of the rib, the lower rib was tapered slightly to place the base of the flange just proud of the line of the skin to prevent fouling the rudder stab. 

The skin was re-installed and holes for the spar attachment marked then removed and trimmed using the factory jig and Ofla knife.


Mass Balance Installation.
The M10 nut was ran down to the face of the mass balance but not tightened - The thread in the base was run out and Loctite 222 applied and ran back till the weight bottomed out and when cured the M10 nut was tightened onto the weight.

Finished assembly ready to rivet

Rudder Frame - Part 1

The frame was assembled as outlined in the factory drawings with all parts clearly marked at the factory for reassembly. Once the frame was clecoed together the pre-drilled skin was fitted and clecoed ready to fit the D-nose. No issues were encountered and the skin was pop riveted to the ribs EXCEPT at the last hole, spar and the upper and lower ribs. This is required to undertake the fitting of the D-Nose and fabricating the faring attachments at the top and bottom.  

Rudder frame assembled and clecoed
Ensure all captive nuts are installed before proceding

Fitting D-Nose
The front former's for the D nose were installed for this operation. The D-Nose is supplied as a pre-bent shape, cut to length with cutouts for the hinges. The main task is to match drill it to the skin/spar while in contact with the former's.

The initial fitting required two flat hockey straps 600 mm long with the D-Nose edge's slid under the under the rudder skin. The skin was maneuvered into its correct location after a number of trial fittings. Once satisfied a single hole was match drilled at the top side and clecoed. Then the skin was formed by hand around the nose rib at that location and a hole marked at the other side with a felt tip pen and the D-Node was removed,drilled,re-installed. This was repeated about half way down and finally at the base. 

Note taper

The force applied at the base nose rib created an error that required rework later when the issue created was noted at the trial fitting of the bottom fiberglass faring. [see note]

This will be outlined in the next rudder blog.

The D-Nose was refitted, checked and then all holes from the running down the spar were marked drilled and the D-nose removed and drilled. The edge was trimmed using the factory jig and Ofla Cutter as outline in previous blog. 

The D-nose was refitted with clecos await final fixing.

Note: If doing this again a former based on the inside face of the lower fiberglass faring would be  cleoced into the rudder attachment mount at the base.  The skin would be formed around this fixed reference to the fiberglass faring that has to be installed later. 

Mass Balance
The kit is supplied with a mass balance and associated hardware. It was unclear on the plans if the two attachments were only riveted onto the former, it was decided to integrate the mounts into the rib. This was achieved by enlarging the two 5 mm alignment hole's in the ribs to suit the OD of the fittings. Both bushes were drilled for 4 [four] 1/8'' pop rivets, reassembled and fixed to the rib's.

Fairing Mount Top

The fairing mounts were manufacture from aluminium strip supplied with the kit. The strip was cut to length inserted in between the rib and the skin. The mounting hole center line was marked and aligned through the existing holes in the skin and matched marked using a 1/8''  transfer punch.

A tapered timber backing was used to support the aluminium during the process.

The strip was primed with Grey SLS Etch primer, installed at both side's with cleco's. 

All holes were now pop riveted. The final two rivets at the back required a 1/8'' x  6 mm pop rivet as the factory supplied rivets foul on each other.

Rudder Assembly Phase I

Cockpit Faring Rear - Part 2

The Tucano require's additional air when operating in warmer environments. With the decision to add faring's at the co-pilot area it was decided to used the third panel to provide air for that area. 

A custom inlet was modeled in 3D and sent to be machined in ABS plastic in China. The cover was riveted to the side panel with 5/32'' pop rivets after cutting an opening. The size of the inlet was modeled on the air vent used on a Cessna 172 so the two should supply more than enough air to the rear cockpit. 

The factory vent is seen as a aluminium folding at the rear of the aircraft.

Cutout in side panel for air inlet

The air inlet shown feeds air into the side cover with the cover sealed at both ends against the side skin with the lower flange sealed with Raven self adhesive foam tape against the skin. A extension to the flange was riveted to the side panel to allow the seal to occur on this edge. Raven self adhesive foam tape 6 mm wide will be fitted to this edge to seal on the side panel.

Note:
The step file for the inlet cover is available to other builders - contact through the Australian Dealer Web Site - http://www.flyinglegend.com.au

Air control system behind panel

Air is directed and controlled by the co-pilot via an adjustable vent with excess air spilling over the middle barrier which is clear of the side skin by approximately 20 mm. At the end this air is allow to exit using two [2] fixed vent which directs this air to the canopy to supply the general cockpit with fresh air. When the adjustable vent is closed all excess air vents to the general cockpit via the two [2] fixed vents. If doing it again I would move the fixed vents forward away  from the canopy latch if only for the aesthetics.

The pilot has two [2] personal vents fitted to the lower panel and will be covered in a later blog.

All material used in construction was 0.012'' 2024-T3 aluminium sheet.

Air inlet co-pilot side - typical both sides - trial fitting

Will this work as described - in theory "yes" but the proof will be in the testing which is a way off but this is why its called an experimental category and this is a personal solution.

The vents used are supplied by Euramtec from their Ebay shop. A nylon mesh luggage rack in a frame was purchased to be used as a map pocket to be covered in a blog later.

Euramtec adjustable and fixed vents

Cockpit Faring - Part 1

Fairings are supplied for the cockpit sides with their locations and arrangements shown in the fuselage manual and the final arrangement is a builder preference.  See:  Fuselage Manual page 25

Factory faring dressed up

Factory Side Panels
The cockpit covers were installed by match drilling using the angle flange attached to the external skin as a template. 
[see image below]

The  instruction's show the fairings fitted under the angle but on this aircraft they will be placed on the top side to create a tidier finish.

Trial fitted the first factory panel [Item 2] and adjusted it to fit and if required trace the outer edge profile and dressed to fit as required. 

The faring was fitted under the side panel's mounting angle and two holes are marked using a felt tip pen, drilled and clecoed in position. All other holes were marked using a 1/8'' transfer punch and drilled off aircraft. 
[see image below]

Angle fitted to drill faring
See notes above

The hinges had been fitted previously as the starboard fairing has to be trimmed around the front hinge

Fitted the second faring, adjusted until a tight fit is achieved with the first then repeat process as outlined above. 

Repeat at the opposite side.

Co-pilot Fairings - Optional
This project is attempting to create the feel the Shorts Tucano so additional panels were manufactured using 0.012'' x 2024-T3 to match the factory covers and profile line from the pilots compartment to the baggage compartment bulkhead. 

The factory advised that when operating in a hot climate's additional air for the co-pilot is required. A custom ABS plastic inlet was machined and fitted to each side side panel to collect air and feed it into the third fairing shown opposite. The air flow is controlled by the adjustable vent's with surplus air vented by two fixed outlets locate at the rear of the third panel. 

Details will be outlined in a separate post.

Flaring Tools 
A series of lighting holes influenced by the prototype were added using suitable hole saws and to stiffen the panels flaring tool's were used.

The benefit to the panels is the stiffening not weight saving, its really just eye candy but help's reduce the hippy look of the panel line chosen. 

The kit shown was purchased from Ebay from FABPARTS 2009 and all worked well on the 0.012'' and 0.020'' aluminium panels.

Another brand chosen for the 2.5'' hole but stretched the metal and buckled a panel.

A replacement die from the original supplier was purchased to finish the faring's. These tools get a personal recommendation in aluminium - they just work even on painted surfaces.

Trail Assembly Port Side

Rudder Pedals - Part 2

Co-Pilots Pedals 

Connecting rods locate the co-pilot pedals

Located the pedals using the rod end as outlined previously, marked its center-line and installed the reinforcing plate to the underside of the floor plate. Both pedal plates had been drilled for fixing to the longeron previously. 

[Refer Pilots Floor Plate for installation notes]

Pop riveted the floor plate to longeron but not to bulkhead until skin is re-installed.

Fitted both the co-pilots pedal assembly's as outlined in Part 1 ensuring that both connecting rods are the same length. Lightly fix with lock nuts as the nose gear connections have to be installed before any final adjustments.


Checked for smooth operation - shimmed bearing gap as required.

Area washers are installed at each rod end to ensure they cannot escape in the event of a bearing collapse. 

Modification
Custom bolts were manufactured from M6 X 45 Unbrako screws. All bolt's where hand threaded to provide the required amount of plain shaft to suit each application and were to replaced all fully threaded bolts used in the pedal assembly's. Threads were trimmed to there correct length and polished using a plastic buff on a bench grinder to remove all sharp edges. 

Nylon or fiber washers install at brake pedal pivot's to adjust clearances to a minimum. 

All bolts were treated with Loctite 222 on assembly and nylock nuts installed as applicable.

Hangar & Custom Bolts

Assembled Pilots Pedals

0.012'' Aluminium shims - to be trimmed before final assembly

For details of the shim construction click here