Tuesday 6 January 2015

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 

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