Entry Step

This blog covers the step and a drag reduction attempt.

Overview
The Tucano has a 20 mm OD tube fixed onto the fuselage hanging under the fuselage creating an easier entry via the port wing walk. This makes entry easy and well worthwhile installing.

The diagram below shows the relative drag created by a tube versus a streamlined tube.

Installation
The first task was to cut the hole through the skin using the mounting point as a guide. As this is no simple circle, so with a little luck one of the rivet holes was on the tubes centre line. This hole was enlarged to 1/2'' OD using a step drill then further enlarged using 1/4'' chain file. The hole was enlarged carefully until the file would run parallel to the inside face of the fuselage mounting tube.

A trial fit confirmed it fitted correctly, then it was secured using 2 x M6 bolts to the fuselage using the pre-drilled holes.

Printed farings for step
and flaps

Drag Reduction - a little
A profile was printed using a 3D printer in ABS plastic to fit onto the face of the tube that was supplied by the factory. These were created as two separate profiles with the lower one fixed to the tobe and the upper fitted and profiled to the fuselage. A fillet of polyurethane adhesive blended the upper profile into the fuselage.

Lower faring fitted

Comment
Simple clean up and looks tidy but compared to the fake exhaust looks like a waste but it all about balance even a little were possible.

A similar clean up was done with the flap hinge and this will be covered later.

The use of ABS is a suck and see as it doses soften at about 70C but is used extensively in automotive interiors and appears to stand up well.

To follow the work find the aircraft on Facebook under Gary Spencer Salt

Map Pocket

This blog covers the finishing of the map pocket

Overview
Any aircraft needs a place to store the mandatory paperwork that must be available to those who rule on any flight.

Installation
The map pocket was outlined in a previous blog.

The installation of the throttle cables needed the bowden cable connecting the rear throttle to cross the backing for the map pocket. This meant that the plastic frame could no longer bear on the skin and a packing of about 6 mm was required to clear the cable. 

Not being overwhelmed by the idea of fabricating a backing it was remembered that a second net was purchased and as luck would have it it was just the right thickness and of course matched its cousin.

There is a local saying in Rylstone "better looking at it than for it" and that was the case here.

The cord was cut and threaded from the frame and then it was placed over the cable using the mounting holes as a reference, the location of the cable was marked and the 6 mm chain file use to shape a slot at the marked location.

Spacer frame

All rivet nuts were chased with a M4 tap and longer M4 cap head screws were sourced and the new frame fitted and the elastic cover overlay-ed and secured with five screws. The covering plugs for the holes were not installed as they look good but make maintenance very messy.

Map pocket installed

Comment
Problem solved - next job

Tail Skid

Blog cover the installation of the tail skid

Overview
The current Tucano kits are supplied with a tail/skid tiedown that was not available at the time of purchase and the factory has shipped this and a couple of other upgrades for my aircraft at no charge.

Installation
The nylon skid was assembled using AN3 bolts and mounting brackets supplied with a pair of AN3 half washers as temporary spacers. These were removed after riveting and provide a small clearance to facilitate removal if required in the future. 

The assembly was aligned on the underside of the fuselage then 3/32'' holes drilled through pre-drilled holes in the brackets into the fuselage and clecoed as required. All holes were drilled through #80 drilled and fixed using 3.2 x 8 mm rivets after removing swaf.

Fairing was outlined in previous blog
providing a more finished look

Comment
Done

Cowl Skin - Part 2

This blog covers the installation of the cowl skin.

Preperation
Installation of the cowl skin required a decision on the type of riveting and it was decided that flush would offer the best appearance. The skin was dimpled using the existing dimpler die with a new riveting gun - GESIPA Flipper.

This was purchased as a replacement for the traditional hand riveter because it offered a mechanical ratchet, one handed operation making installation 4 mm rivets practical in small places. 

A trial was conducted using the Flipper with the dimple die and it was found to produced a high quality dimple. 

This was a result of the one hand operation allowing the other hand to center the die using the ratchet to lock the assembly. 

The first click tightens up just enough to lock the die while allowing final centering with the last click bottoming the die locking the assembly. A push forward on the handle unlocks the tool releasing the dimple die. 

The  only change was that the nails used with the die require changing about 20 pulls to maintain consistency. 

Highly recommend are the Australian agent ToolFix at Kings Park Blacktown. I managed to kit the new gun because of PRM [Please read manual]. They reassembled the gun checked it out at no charge - truly excellent.

Next the firewall and new tabs were dimpled using the same procedure. Finally the channel spreader was countersunk using a micro stop and 120 degree tool. The skin was fitted, fully clecoed, doubler's fitted, sealed and riveted onto the airframe. With all checks completed the clecos were removed one at a time and riveted using 3.2 x 8 mm countersunk pop rivets.

All faces dimpled ready to rivet

Skin fitted and dressing edges straight to accept covers

Note: cover is hand made and this is not required with the
factory panels which are CNC punched.

Silicon applied to weather proof cover.

Note: Spread silicon very thin to allow doubler to be flush after riveting
Too thick as shown

Packer was installed under channel
before final riveting

Skin and doublers riveted to airframe

Aluminium 0.020'' added to cover gaps created by the the profile adjustment

Cowl Modification - Part 1

This blog cover the modification to the cowl skin to align with the canopy frame. 

Overview

When fitting the canopy and top cowl as part of the preparation for the shroud a alignment issue was noted. It was decided to modify the cowl profile to match the canopy as this appeared to be the most direct route. 

I can see no error in how the work was undertaken to create this issue but I did email the factory for advice. Franco at Flying Legend advised that a new frame design was to be available in a few weeks but I elected to modify the cowl to avoid the lost time. 

A pair of metal horseshoe's that has begin incorporated into the new design will be fitted onto the canopy on their arrival from the factory.

Misalignment noted at both ends

The factory cowl sheet aligned perfectly with all holes in the fuselage allowing it to be used as a drilling jig. 

Manufacture

The mounting lugs on the front bow were removed and a duplicate manufactured but with longer leg on one side.

The existing sheet was laid on a new sheet of 2024-T3 sheet on a under sheet of foam insulation.  The foam allows the sheet to be drilled and clecoed with the foam providing bite and fixing the sheet. The side that attached to the fuselage side was extended by 25 mm and then all the factory holes duplicated except the side holes. 

Duplicating cover existing cover
The blue tape is to prevent drilling unwanted holes

Removed existing tabs 

Port side tabs installed

The new sheet was refitted to the aircraft and then a set of new tab's 75 x 20 x 0.020'' folded for re-installation. The canopy was shut and with a tab placed under the cowl a spring clamp secured the tab to the frame. Next the canopy was closed, fit checked and if OK, the holes marked, drilled and then clecoed back into the frame, this operation was repeated 14 times over a few hours until a new profile was created.

The openings for the inspection panel were cut out for installation of the doublers then all edges were dressed using files to final profile.

The new cover was treated with Henkel Alodine 1200S Brush On alodine in accordance with the directions supplied and set aside to air dry.

When dry the panel was clecoed into position and all the lower edges were now matched drilled and the panel removed and the edge trimmed and dressed. 

When complete the panel was fully clecoed into position.

A pair of factory supplied doublers were now cleoced into position with no issues.

Ready for final riveting
The fold through the lower rivet line at 5+ degree [approx] was added 
to create a tighter fit when riveted

Fuselage Vents

This blog cover the additional of fuselage vents

Outline
In a effort to improve the cooling drag of this Tucano it has been decided at some future point to add gear doors to the nose gear. This however will create a problem with removing the hot air created by the radiator, inter-cooler, engine and exhaust as at this time it all escapes from the wheel well.

As the guide rails for the ballistic parachute are not used on this aircraft with a combined area of about 2.25'' and are there to be used for another task. 

Side vent's used on Jeep's were selected having nearly the same overall width as the existing opening allowing rivets to fix it to the side of the fuselage.

Two models were ordered, a 12'' and a 18'' to be used in the wheel well doors.

Supplier: Run Cool Hood Louvers

Skins
The rip off side cover supplied with the kit were used to create an infill panel riveted to the underside of the existing skins. It was cut 85 mm wide and match drilled to the longeron. 

Outlet ramp

Firewall Seal

A tongue was cut about 125 mm long and riveted at it's end onto the channel face.  High temperature silicone was applied at the edges to seal the air to the ramp created. This area has to be sealed regardless as its a direct channel into the cockpit for unwanted fumes.

A infill piece for the front was cut from 0.016'' 2024-T3 sheet with a cut-out under the louvres [seen in grey in the image  above] 

Finally two small angle were cut to infill the top and bottom edges of the opening at the firewall and then riveted to the longeron faces. High temperature silicone was applied to the face in contact the firewall before riveting.

Louvre's

The louvers were cut to provide 6 vents with the top edge was angled using a set of 4'' duck bill pliers with a small angle was created on the lower flange to ensure a tidy fit. All the edges and rear face were sanded, as the metal is fairly heavy there is adequate to remove all marks and to flatten the back.

Finally 12 and 24 mm radius's were applied at each corner as required then both vent's were  primed and allowed to dry.

Louvre fixed onto top skin

Fitting
The top two holes pick up the existing mounting holes with the lower three [3] to be matched drilled.

Each vent was fixed using 3.2 mm x 10 mm pop rivets onto the side of the fuselage.

Fuselage Floor Plate - Part 3

Note: Location of the rivets securing the plate to the longeron should be considered with the location of the seat bolts - our location was adjusted to line about the center of each rivet group.

This post should be read in conjunction with Part 1 on the floor plates. In particular the installation of the angle support for the co-pilots plate at Station 3.

Port Floor Plate
Drilling mounting holes using factory jig

Both plates installed square to the longeron and drilled to accept 1/8'' pop rivets using factory jig at 30 mm pitch. At this time the mounting holes into the angle mounted on station 3 are not drilled as the lower skins have to be installed for this task. The reinforcing plates are to be installed once the location of the rudder pedals are determined.

Fixed the plate with 1/8'' countersunk pop rivets using the holes drilled previously.

Finishing the Floor Plates
Once the pilot rudder pedals and connecting rods the location of the doubler was determined and fixed as per the front floor plates.

Floor Plate Attachments
Rivets for attachment at Station 3 are not fitted
allowing station to be aligned with pre-drilled skins

Fuselage Floor Plates Part 2

Co-Pilot Floor Plate
Drill the floor plate at 60 mm centers using the factory supplied jig. Fit it to the top of the longeron and match drill two holes, fit clecos and finish the balance. Remove floor plate then de-burr holes.

Refer notes: Fuselage Floor Plates Part 2

The seat brackets sit on top of this plate so all holes are countersunk except the last two at Station #3.

Entry Bracket
The bracket required to mount the foot entry was not picked up on the initial reading of the plans and at installation it was noted that the mounting holes will require riveting to the top flange of the support angle. This places the removable floor plate on the top side of the bracket, so it will have to be joggled to fit this installation. The piece marked on the photo to be trimmed will be cut from the bracket to allow a straight joggle.

Position the bracket and mark it's location onto the top side of the port removable plate. The floor plate will have to be trimmed and drilled to these reference marks to fit inside the bracket profile. Cutting off the existing return and drilling a clearance hole for the circular mount allows the plate to fit the bracket.

Locate bracket with floor plate fixed in position on the longeron, drill two hole's into bulkhead at Station #3 locate the bracket.

Remove the floor plate, drill a hole through the flange of the angle to allow the step to be inserted into the bracket. 

Match drill holes into the angle faces from the bracket, countersink and rivet. 

Match drill all the holes into the bulkheads and pop rivet. 

Check the floor plates and adjust to fit inside the perimeter of the bracket then joggle to fit.

Insert the mounting shaft into the mount from the top side and mark its location onto the flange of Station #3, then trim to clear. This hole will have to be replicated through the skin before its final installation.

Trial fit of bracket

Note: An alternative would be to reduce the overall length of the angles allowing the bracket to be installed matching the top-side of the angle. 





 Joggles in Aluminium

Fuselage Floor Plates - Part 1

There are 6 floor plates to be installed into the Tucano for the Pilot and Co-Pilot. Some are removable and others are fixed - refer manual for details. Each plate should be clearly marked as removable or fixed.

Pilots Fixed Rudder Floor Plates
The plates were marked out to place the mounting holes on the center line of the longeron with all holes drilled 1/8'' [3.2 mm] at 60 mm centers using the factory supplied drilling jig. 

Position plate by aligning with the end of the wheel well at Station 2 - match mark two holes onto the longeron centerline - drill and cleco. Match drill all the holes on both sides, remove the plates and de-burr. A 12'' long #30 drill makes this task possible with a large battery drill and are available from Yard Store in the USA  -  get a range they are well worth it.

Hint: The aluminium used for the floor plates produces pronounced burrs but a small painters stainless steel scraper with the corners rounded and just a hint of rake on one side is "truly  excellent"  at removing them quickly.

Cleco both plates back into their location and mark the center line from the cutout in the wheel well. Remove and locate the reinforcing plates equi-spaced about this center and match drill. These are machine punched and will drill correctly from either side. 

Place on the underside of the floor, pop rivet with the taper to the fuselage side.

Temporally re-install with clecos.





Pilots Removable Floor
The holes for the two removable plate's located between Station 2 - 3 can be marked out and drilled at 60 mm using the factory jig but decide were to place the last odd hole - all holes are drilled 1/8'' [3.2 mm]

Hint: Tape all open edges between mating services and anywhere a crevice is created to prevent ingress of swaf. A large amount of swaf was trapped on this install between the wheel well and the longeron with removing the rivets the only way to release the swaf.

Floor Supports Angles
There are a number of angles required to support the removable panels at Station 2 - 3 and are fabricated using the 30 x 30 x 1 mm angle supplied with the kit. 

A level was used to establish the height on Station 2 at the fuselage side using the top side of the longeron as the reference. The mounting holes in the angles were drilled at 30 mm centers using the drilling jig then the station former's match drilled.

The bulkhead Station 3 require's support angles at both sides for the pilots and co-pilots floor plates. 

There is a 15 mm height difference between the pilot floor and the co-pilots floor and on this install a deeper angle was installed at the co-pilot side to allow fixing to the bulkhead. Even lowering the rivets by the required amount the stems just cleared the underside of the flange on the pilots side. [See image below]

Note: If doing it again install the co-pilot angle with the pop rivets say 7.5 mm from the top of the angle. Install the pilot angle drilling through pre-drilled holes to ensure that both are held tightly onto the bulkhead. On this install Teck screws have to be installed to achieve the same result. 

Install the middle plate and position the removable plate, match drill from the outer removable plates to provide the two holes in the longeron, cleco then match drill the plate and longeron with the factory jigs. 

Enlarge holes to 3.5 mm to allow easier re-installation.

Trim panels as required to achieve an acceptable fit

Note: To undertake this work the temporary rivets for the lower skins have to be removed to gains access.  Do NOT  match drill floor plates to the bulkhead or angles at Station 2 - 3 as this locate's the bulkheads without reference to the mounting holes for the skin. 

Fitting Riv-Nuts
Install M3 riv-nuts for the removable plates into the longerons, all the holes have to be enlarged to suit, fit factory supplied supplied nuts then reassemble using with a few M3 x 10 screw's, check the fit and adjust as required.

View Starboard Side Station #2 - 3
Note: 1/2 x 1/2 angle stiffener and double row off rivets to mount angle supports for pilots and co-pilots floor supports. The holes in this installation are at 30 mm when drilled in error - 60 mm is correct

Adjust the pilots fixed panels folded edge to align with the skin - this can be done with a straight edge held on the bulkheads - packers may be required when these are riveted to the side skins - the key here is to get the angle right. This can be achieved using a block of hardwood with a slot cut into it by bending the edge along its length [it works] - refer video link below.

The bulkhead flange on Station 2 supports one side of the pilots floor plate. On this installation it was found that a couple of aluminium washers were required to align with the removable plates. These were super glued onto the under side of the plate and holes drilled to suit 5 mm aluminium pop rivets. 

Note: To use smaller rivets custom washers would have required  washers machined to suit.

Modifications
The removable floor plates were reinforced with two [2] 1/2 x 1/2 x 1/16 - 2024-T3 aluminium angles running  fore to aft as the factory floor plates seem a bit flexible to take my full weight on entry. It should be noted that the fixing screws and skins were not fitted at the time.

Footnote: The only problem was this tool using the drill forgetting to stop at the pilots fixed plates as they were not marked "fixed" anywhere. With a long day and the before mentioned tool now running in Derrr mode, all the pilot fixed holes were enlarged only to be discovered when the drilling stopped.

Refer opening note on marking plates. The panel were fixed using 5 mm pop rivets but that was more good luck that anything else...!

Pilots Floor Plate Station #1 - 2 Port Side

Pilots Removable Floor Plate - Station #2 - 3 Port Side

Removable Floor Plate
Holes were pitched at 30 mm, every second hole opened to clear the heads of screws in the lower plate allowing the middle plate to be removed independently of the others. The factory hydraulic hand pump is located under port removable panel.

Flange Bender Make your Own 

Images Fuselage Kit

While the work to complete the hanger proceeds apace I have finished unpacking the parts shipped and packed inside the fuselage. I have taken a few photos to show the fuselage as is delivered. The photos reflect the quality of the assembly provided in the quick build kit. All the holes are matched  drilled and ready to be riveted as and when required

Some of the panels are fixed temporally and will be removed for final trimming and fixing after installing the necessary hardware in the fuselage

Starboard side Firewall and Rear Turtle Deck

Rear Elevator Deck

Cockpit looking to firewall and Rear 

Main Spar Box at rear and looking to Firewall

Looking to Fuselage Rear - Baggage compartment?

Looking to Rear of Fuselage - Note holes thru the side for flap mechanism