Tuesday 16 September 2014

Stab Assembly - Part 1

The stab kit consists of a series of pressings, skins and mounting brackets. All holes are matched drilled by the factory so the major task faced by the builder is the correct assembly of the parts. Begin by identifying the parts and their locations by studying the 3D illustrations in the factory assembly manual.

You will need about 150 clecos to fully assemble the frame ready for riveting. All rivets used are 1/8 pop rivets supplied by the factory as part of the kit.



As part of the assembly four [4] captive nuts supplied MUST be fitted to the inside of the rear spar. This was missed by this builder and later required a quick back track to under take the task.

The front attachment has to be now prepared to allow the frame to be installed into the fuselage. Fit a bolt through the single attachment point - the hole on this one was chased out using a tapered hand reamer fitted to the battery drill. Align and clamp then match drill one 1/8'' hole through then fix with a cleco as shown then drill all holes to complete the part.
At this point assemble the rudder hinges. The bracket with the slots are the top hinge. Note: The bracket with the bearings are fitted to the rear stab spar in both cases.

Assemble using a AN4 bolt and nylock nut with a aluminium full washer placed on both bearing to  space  the  brackets clear of the bearing faces. These have too be disassembled  to install the brackets into the rudder later.
Before fitting the rear spar to the fuselage install four [4] to the rear bulkhead and the deck. This builder chose to rivet the skins with the stab installed to the fuselage. The rear spar is fixed at six [6] point provided with AN3 bolts and nylock nuts.  Refer factory assembly manual for details. When complete fix at the front using a single bolt and nut.



The rear rib on this kit required a slight trim to allow fitting. Once correct fit clecos to the two [2] holes then match drill from the front - once done fit the final rib and cleco. Fix all 5 points with 1/8'' pop rivets. Review the factory notes for final details and only when 100% sure fit the skin to the open side in preparation for riveting. If there is any doubt ask your technical adviser to come over and check all the points.




There are two [2] lower infills strips to complete the rear rudder shroud - slip under skin and align as shown then match drill as shown. Both shrouds MUST be drilled before fixing to allow access - see image above. The drill shown is a long series aircraft drill with its primary feature being a short area of fluting compared to its commercial equivalent.

The backing strips located on the inside face of rear spar located at the base shown on the drawings and MUST be installed as in accordance with the factory drawings. The backing strips are pre-punched and will fit either side.

Note: The stab will have to be removed to allow installation of the horizontal stabilizer but this builder decided it would be a good place to start , access would be easier and with this approach the frame is jigged to the aircraft during assembly.





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