Wing Installation - Part 2

This blog covers the installation of the aileron and flaps.

Overview
The ailerons and flaps are supplied pre-skinned with the D noses to be removed, trimmed with this task is to be undertaken after the installation of both items onto the wing.

Ailerons

Flaps

Aileron Hinges 

Outboard hinge

Inboard hinge

The hinges are stainless steel foldings with the mounting holes slotted to align the aileron the tips and flap. These were fixed with AN3 bolts then lightly nipped allowing adjustment.

With the hinges installed onto the wing, the other mating half was fitted to the ailerons using AN3 bolts and washers.

Note: No nuts are required as all holes are predrilled and fitted with anchor nuts at the factory

Alignment
The jig that was used to align the tip is reused to set the aerilons alignment to the skin, once set the aileron is locked into position with masking tape and rechecked.

Once satisfied we moved to the flaps.aileron

Alignment with jig
Tape marked the edge for the aerilon
for reference to the other side

Flaps
The angle brackets are sorted out with their respective mounts with only the outer hinges installed at this time. The hinge arm is fixed to the bracket with AN4 bolts and the bracket then inserted in between the faces of the two [2] angles then clamped with a C clamp mentioned in part 1.

Next, the inboard edge is aligned using the jig and two [2] people to support the flap, with the flap and aileron aligned and checked to confirm that they form a straight line. This required an amount of adjustment at the aerilon then flap until a satisfactory result was achieved.  Once aligned the flap is taped as per the ailerons, and all checked again, and the aerilon bolts were nipped up tight.

Taped up aileron and flap
Factory photo

Next, the brackets were matched drilled as per the builder manual and bolted. Finally, the centre bracket was swung into position then drill and fixed as per the outer brackets.  

Flap hinge drilling
factory photo

At this point, we all stood back and were impressed by our efforts with more coffee to celebrate.

With the flaps disconnected at the hinge point as were, the ailerons and these were placed to one side for later work. The rivet points in the werelion hinge were marked with a 4 mm drill for riveting - these rivets lock in the alignment at that end.

Next job was to remove both wings and install them in the vertical on saw horses to allow kitting out. The remaining nose skins are removed to allow trimming and to fit the fuel tanks.

Ready to fit onto saw horses

Skins to be trimmed for installation

Comment
None really but it did look so cool with the wings on.

Wing Installation - Part 1

This blog will cover the installation and alignment of wings.

Overview
This Tucano requires the builder to drill and ream the spar straps to a 1/4'' after setting the angle of incidence and washout. 

In attendance at this time was Franco and Alexandreio Rummolino from Flying Legend in Italy to aid and train this builder ensuring the correct procedures were used on this project and to aid other builder in the future. This is without question a 2 - 3 man operation and under no circumstances try this one up so you will need beer and steaks.

The design of the Tucano wing connections have changed significantly with the upgrade to +6/-3 with the straps being replaced with 2 pins reducing the assembly time to a quarter of that required for the straps but the setting of the angle of attack and twist remain the same.

Mounting Frame

Gorilla Work Platforms

The factory aircraft is mounted on a series of stands to undertake this process but not wishing to manufacture the stands a trip to the hardware resulted in the purchase of two [2] adjustable work platforms and stands. 

Craftright Saw Horse

A sheet of builders foam was used to pack the deck and to provide a suitable mount for the fuselage onto the stands.






Installation
All spar straps, packers and plates were assembled on a bench to be fixed to the wing with M6 screws using the factory drilled holes and procedures.


The aircraft was leveled using a digital level place across the longeron in front of the instrument panel and then using a length of aluminium channel placed along the top row of rivets on the fuselage side to confirm it was also level

Note: This instrument as a tolerance of +/- 0.1 degrees which is suitable for this application

Google: Digital LCD Protractor Angle Finder Level Inclinometer.

Level along the side

Level across Fuselage

The main spar caps on the Tucano were manufactured using a series of laminated sheet aluminium angles, so before any work can be commenced they had to be cleaned using a combination of brushes and vacuum cleaner to remove all swarf that could included itself between the laminate when the factory bolts were released. 

The front rib was removed to provide access for drilling.

Note: All spars now have aluminum extrusions manufactured to replace the laminates but the rules are the same

At this point the factory bolts were replaced with 5/32'' [4 mm] screw clecos to close the spar laminates at two [2] locations then two other holes were enlarged to accept 6 mm bolts. Additionally the internal connector plate was fitted to the wing spar using 1/8'' clecos and then a C clamp to tie it to the rear spar to allow adjustment of the washout at the next step

Washout at root has been sent and the holes
on the fuselage side match drilled

Before any work was undertaken clecos are installed to ensure the wing's shape is locked back into the profile from when drilled in the factory jigs, these were placed on about 150 centers along the full length of the spar and the skins to the ribs.

Note: Remove only the first skin to provide access to the spar connection points and do not remove the temporary rivets or other skins at this stage

The wing was inserted into the main spar then secured with two [2] - M6 x 60 high tensile hex head bolts per side usings the factory drilled holes while supported at the tip by the saw horse. 

Wing Attachment Described
superseded buy new design below

With the wings fitted and the dihedral was checked using the digital protractor and a 1200 mm length of aluminium channel to average out the difference created by a overlapping skin at the same location on both sides. Once the angles matched the pairs of M6 bolts were tightened to retain the setting. The saw horse was relocated then packed as required to ensure the wing could not slip at the connections.

Setting dihedral

Washout

The twist was set using the rear spar straps and two [2] clamps per side in conjunction with jigs manufactured in 6 mm perspex.  

Note: There are six [6] x 11'' C-Clamps required for this and other tasks on the wing - these were purchased on EBay and were of a excellent standard for the money

Setting Dihedral

Both angles were rechecked to confirm no change from the tightening of the bolts

Note: When checking and setting the angles specified the most important number is the two that match with reference to the tolerance of the protractor.  If found to be floating between two values adjust to achieve a steady value

Setting Washout

The next task was to set the washout using jigs manufactured here from factory DXF files and 6 mm perspex that worked extremely well on the day.

There are two jigs, one for the root and one at the tip. Zero the protractor of the fuselage datum and then rest one jig on the rib profile and with the two notches aligned with the front and rear spars.

Note: The procedure and location must be the same at both sides - the most important outcome is not the angle but that they are both the same.

Setting washout

Setting washout at root

With the jig on the the angle is checked  and adjustments were achieved with a firm but technically correct hand thump on the top of the spar at the fuselage intersection.

Mission accomplished

Aligning Wing to Fuselage

The final task is to check the alignment of the wing tips, This was done with a tape measure, three [3] people, two [2] to hold the tape plus one [1] person to support the tape in the middle.

Alexandreio, Joe [translator] and Franco
checking the diagonals

Final Check

After all the adjustment recheck all the previous settings then one final check to confirm the numbers then drilling could commence.

Drilling

The next task was to remove the temporary 6 mm bolts one at a time - 6.1 / 6.2 / 6.3 mm and then ream to 6.35 [1/4'']. Two holes were prepared in the outer wing panels and bolts inserted using a with a soft hammer, next this task is repeated on the fuselage connection and bolts fitted. 

Note: Only one bolt is removed at any point and no additional work is undertaken until it is replaced and the bolt hand tightened

As each hole was drilled a  AN174 bolt, MS21042 nut and washer was installed and lightly tightened by hand. Normally bolts are placed fore to aft but in the case of the spar straps the rear bolts are to be install with the nuts visible in the wheel whell for inspection.

After coffee the diagonal was checked again as was the dihedral. Once reconfirmed all the holes in the outer panel were drilled.  At this point the comment can be made that the material used for the straps is as tough as anything that I have ever encountered using hand tools. 

The bolts on the fuselage still have four [4] bolts to complete and this is done when the wings are to be installed for the final time after painting.

Both wings were now placed on a pair of saw horses and the twist checked with the jigs. The work here will be covered in a separate blog.

Note: All bolts are lightly nipped and will at installation be torqued to specification using a calibrated torque wrench - Never guess the torque as the required amount is a light nip and unless you have a  lot of experience use a torque wrench - professionals do not guess.

Comment

Firstly the Ozito battery drills clutches were not man enough and this required a quick trip to the local hardware to purchase a new electric and battery drill. This was further complicated when a drill broke in one of the inner fuselage holes required a couple of hours tapping, spraying and sweating to remove by an experienced  team from the factory - Oh Joy..!

In fact the last six [6] bolts on the port wing were done in about the same amount of time with the all the tasks taking about

Why point this out well the new aircraft do NOT use straps just four [4] pins and the image below shows how much fun you will miss out on.

I have tried to document this a closely as could be done after the event but the manual rules and should be read as the only source of all procedures - OK..!

New Wing Attachment

Brake Reservoirs - Part 2

This blog covers the installation of the brake reservoirs for the toe brakes 

Overview
The installation of the US manufactured fittings created problems because of the mix of NPT & ISO threads. Access to both reservoirs would be through the inspection panels located in the cowl.

Installation
The first task was to install Aeroflow NPT to BSP elbow adapters to allow the use of the NPT brass fittings. 

The factory supplied reseivors required mounting brackets  these were fabricated from 2024-T3 sheet in a channel with a return tab at the base to carry the weight of the reservoir. with edges were covered using rubber channel.

Brackets

Two [2] M3 rivet nuts were installed from the firewall side match drilled using the fabricated mounts. Once installed the mounts were fixed onto the stem side then fixed with M3 pan head screws with the gap created allowing cable ties [2] to be slid behind and around the reservoir for fixing.

Cylinder Assembly

Both reservoirs were piped using black 3/16'' NSR nylon tube and 1/8'' NPT SAE female  connectors selected to suit the location. 

All threads were treated with Permatex PTFE thread sealant at installation.

To provide strain relief aluminium P clamps were fitted onto the firewall to provide support to the connection located on the rudder pedal. 

Note: All screw threads were treated with thread lock at assembly

P Clamp

The rudder pedals were fully cycled to check operation and to confirm that the pipe would stay retained during operation. 

Comment
Worked as intended but aluminium fitting would have been ideal but none were available to save weight.

Fuel Line - Fuselage

This blog covers the installation of the fuel lines in the fuselage.

Overview
The factory is currently upgrading the assembly manual to show routing for the fuel lines but my kit is an earlier model and the work here is for record only but may still have some value.

Sample drawings from the new Tucano manual
Removes all the builder guess work

Manufacture
The lines for supply and return are all aluminium 3/8'' giving a bore of 6.5 mm within the manual specification and was sourced from AeroFlow in a coil form. 

One of the issues of coiled aluminum the need to straighten for aesthetics and this cannot be achieved by hand or rolling across a floor. Searching the web located a tube straightener from Kwix UK that seemed to be right for the task and that was cost effective.

Kwix UK straightener

Straightening tube by hand to get the worst of the bends out then the straightener was run along the tube, multiple passes at different point around the tube's circumference worked best and once the tube is straight the roll can be run along the length in a rotating action to obtain that final adjustment.

Firewall bulkhead fittings

Gasolator bulkhead fittings

Note: The tube straightener creates fine tram lines but are removed when worked as described.

Flaring tool

The length of the tube at the firewall end was flared using a Rapid 37 degree flaring tool then inserted through the aircraft using holes drilled for purpose. At the firewall AeroFlow 45/90 degree full flow bulkhead elbows were fitted and the lines fixed using AN nuts. All flares edges were polished using 400 grit aluminium open cut to reduce the chance of cracking.

All lines were protected running through the bulkheads on commercial grommets with lines supported by automotive line separators. Separators did not come in a suitable size so before installation 1/4'' separators were drill to 23/64'' to allow firm clamp on the pipe.

Note: Sharp edges created by drilling were all chamfered before installation

Barb Elbow

At the tank end the line was cranked towards the fuselage and terminated on AeroFlow 45 / 90 degree full flow elbow bulkheads. The tube was bent using suitable bender, marked then cut using a tube cutter then flared in location.

Connecting the supply and return to the tank AeroFlow hose and AN6 - barb fittings were selected allowing a 3/8'' tube pickup and 5/16'' return lines secured with S/S worm drive clamps.

Gascolator / Fuel Filter
With the firewall filling and guessing it was only to get fuller a alternative location was sought for the gascolator and filter so when in doubt read the RV8 blogs. A number of these builder have chosen to place the item in their wing routes and this was seen as a possibility on the Tucano.

After thinking about the issue it was decided to install them both under the co-pilot rudder pedal foot rest as this was already a removable cover to allow access to the turnbuckles for the rudder. 

ACS Gascolator

A pair of ACS gascolator were installed one for each tank in conjunction with AN6 aluminium filters fitted with serviceable sintered brass filters. A mounting bracket for both items was fabricated using 0.020'' / 0.040'' aluminium and alodined before installation. 

An extension to allow the valve to be accessed from the underside of the skin for fuel drain checks will be fitted when the skins are installed.

Allowing this bracket to be removed with one bolt should mean that the gascolator and filter can be removed for servicing.  

Gasolator and filter
Required for the bladder tanks only

BRACKET DIAGRAM

To achieve this, it was decided to secure the mounting using the rear bolt located on the seat base and an alloy clip installed into the lower longeron secured with two [2] 3/32 C/S pop rivets. Final fixing will occur when the skins are fitted in this area

A series of Aeroflow swivel elbows were installed with suitable hose and sized to prevent chafing when in service. 

Note:  These are very expensive fittings but were required to achieve the design intent

Comment
Many days were used to work out the routes then gain the courage to drill the bulkheads and assemble the materials just to get it all to fit and look like some thought had been applied. 

The factory design will allow the lines to be formed on a bench - Half of mine were finished under the aircraft with a flaring tool that proved to be hard to control away from the bench. 

While Aeroflow tube is very ductile and easy to form by hand it is crushed to the die size of the flaring tool when fully closed and if a re-flare was required the tube had to be cut back a minimum of 25 mm. 

Tube straightener indispensable - worth every penny.

Dump Valve

This blog covers the installation of the hydraulic dump for the undercarriage.

Overview
The factory supplies dump valves which on the current factory aircraft are installed in the floor just in front of the nose wheel well. Without installing them, it was decided that the access would be a difficult for this builder when harnessed.

A Matco dual park brake valve would allow the emergency extension circuit to be activated using lockable cable mounted on the secondary panel. Of concern is the restriction created by the integrated check valves but as the undercarriage on the Tucano is not a free fall system and is pumped down in an emergency it would seem not to be an issue. The dual port design allows both the fluid from the up circuit to return to the pump reservoir while connecting the down circuit  to the hand pump in one operation.

Matco Valve

Cable T-Handle Button

A button operated cable was selected for the dump requiring a deliberate action to activate it, a  length of 6' was selected but on arrival it had a attachment at the end not apparent at the time of ordering - more later.




Installation
A 0.040'' x 2024-T3 aluminum plate was cut, alodined then riveted into the corner of the lower panel on the opposite side to the emergency pump using 4 x 3/32'' c/s pop rivets. A angle return was included allowing the fuel lines to share the same bracket.

A graphic for the panel was drawn with Draft Site, edited in Inkscape and saved as an EPS file for printing.

The Tucano spar has provision for two x 20 mm dia holes through the spar face with a suitable doubler both holes were drilled then edges polished with 400 grit aluminium open cut then installed a pair of 50 mm OD x 0.040'' 2024-T3 doubler fixed with four [4] 1/8'' pop rivets. 

Factory drilling details to suit design 

Note: This drilling is different to published photos but allows the dump valve to be located in the hydraulic bay.

Next the Matco valve was fitted onto the side of the rib adjacent on the starboard hole with the actuator lever located about the 20 mm od hole center while being secured using M4 x 30 mm screws via rivet nuts fitted previously to the rib. 

Dump valve installation
P clamp was installed at the end of bowden cable

P Clamp

The actuator cable was installed running down the side of the wheel well, then along the floor through existing openings in the seat mount and finally through the spar opening. 

The cable was secured using a series of alloy AN3 [4.8 mm ID] P clamps drilled to 6.35 mm to match the OD of the cable outer and then secured using M4 x 16 S/S countersunk screws fitted into rivet nuts installed into the floor panel.

Note: Running through the seat frame was not the prefered option but the available length of the cable created limitations for any alternative routes.

The six [6] foot cable was just long enough but the swaged fitting at the end useless a decision was made to remove it using a Dremel motor tool, it was slit on both sides and the sleeve removed then the threaded attachment cut leaving about 2 mm attached, finally steel eye was crimped onto the cable behind the lug allowing attachment to the valve lever. The eye was secured with a AN3 bolt with nylock nut with a custom spacer machined to clear the arm and to support the cable in it's correct location. 

Note: Fitting was sourced from Hobby & Engineering Supplies  Part # SM-EYE

One of the most time consuming task was the mix of NPT / ISO threads creating the need to manufacture custom nipples to connect the hand pump, shuttle valve using the metric hose connectors. 

Dump valve actuator

Note: These issues resulted from the installation of an alternative emergency hand pump  with remote dump valve.

The factory supplied 6 mm od hose was used for the high pressure circuit in preference to rigid line for ease of installation with only a slight weight penalty with nyon 6.35 mm od tube used in the low pressure supply to the hand pump.

All hoses were secured to the airframe as required with aluminium line separators used by the automotive industry. All fittings were fixed using M3 rivet nuts and pan head screws. The separators were lined with Kapton tape before assembly to protect the hose.

Note: All the high pressure fittings and hose were supplied by FREN TURBO Italy.

Comment
The suitability of the valve chosen cannot be verified until emergency dump tests are conducted but the the manufacturer replied to a query that all valves are tested to 1200 psi and with the hydraulic pump labeled at 800 psi [60 bar] maximum pressure this creates a 1.5 : 1 operating margin.

The button cable was an expensive choice and the builder would examine cheaper lockable option if doing it again

The Dremel motor is an overrated tool but the new snap on 1.5'' cutting discs combined with a flexible drive has made the tool useful for the tasks above, in fact there would be no other way to remove the end without it.