Category: 4 – Fuselage

Preparing the Center Fuselage – 6

I removed the clecos and prepared the parts for riveting. I did not dimple the holes in the aft edge of the F-776 bottom center skin because they would match up with the F-706 bulkhead and F-778 bottom aft skin later when the two fuselage halves were brought together.

I then dimpled the holes in the skin and the ribs that would later match up with the lower aft tabs on the F-725, 726, and 727 baggage ribs.

Time: 8 hours.

Preparing the Center Fuselage – 5

It is important to note that the rivets at the intersection of the spanwise row across the forward F-704 bulkhead and the fore-and-aft lines along the stiffener are shown as AN426AD3-6. I machine countersank these holes through the F776 skin and into the bulkhead. Rivets through these holes would later attach the floor stiffeners and a smooth inside surface would help fit the stiffeners properly.

Once the bottom skin was clecoed on, I fit and drilled the F-704H side doublers to the center section.

Time: 4 hours.

Installing the Auxiliary Longerons and Forward Longerons – 2

I made the two F-719B Angle Clips shown on DWG 23 and used them to help fit the F-719R&L Forward Skin Stiffeners to the skin in the same manner as the F-713 longerons.  I noted that the joggled end of the F-719 goes aft and laps over the edge of the F-704 bulkhead as shown in Sect H-H’.

Time:  2 hours.

Preparing the Center Fuselage – 4

I drilled everything to final size except for the aft two rows (spanwise) on the F-776 center bottom skin.

I fit and drilled the F-623 corner ribs after fluting the F-623 as necessary to fit the skins, and as I was installing steps, I also trimmed the flange to clear the step tube.

I made the F-623A forward and aft attach straps.

Once again, I fit the front half of the F-704 bulkhead to the rear half. I used the pre-fit bolts and spacers I had made earlier to hold the bulkhead together. Then I drilled the holes on the forward edge of F-776 to size.

Time: 4 hours.

Preparing the Center Fuselage – 3

I installed the nutplates on all the seat ribs. Since the screws generally fit quite tight in nutplates, and because there isn’t much room for a screwdriver on the outboard edges of the floor skins, I ran a 8-32 tap through the nutplates to make it easier to install the screws. I was careful to use a lubricant on the tap.

I attached the rear half of F-704 center section bulkhead to the F-716 and F-715 seat ribs being careful to have the modified ribs in the proper place. The F-716 ribs were clecoed, but the F-715 seat ribs were not drilled to the center section until later, so I held them in place with clamps for now. As I was going to install the optional steps I cut the F-725 baggage ribs with a 1 5/8″ hole saw using the prepunched hole as a guide.

I clecoed the F-725, 726, and 727 baggage ribs to the F-705 rear spar bulkhead. I then clecoed the F-705 bulkhead and ribs to the aft ends of the F-715/716 seat ribs. I then inserted the F-916C spacers at the necessary stations and clecoed the F-776 center bottom skin to the center fuselage assembly. The skin held the F-715 and F-716 seat ribs in correct alignment.

Time: 3 hours.

Preparing the Center Fuselage – 2

I modified one F-716-L and one F-716-R Seat Rib by adding the F-716B Seat Rib Access Plate and cutting the rib. The top of the ribs needed to be removable to install the control system.

I also modified one F-716-R and F-716-L Seat Access Rib by enlarging the lightening hole in the forward portion. The extra space was needed to allow the controls to move.

Time: 1 hour.

Aft Fuselage Assembly – 5

I continued by riveting the F-779 and F-778 bottom skins to the bulkheads and J-channel. I then riveted the F-773 skins to the bulkheads up to the upper J-channel, and to the J-channel itself, but no higher. The top of the skins have to be able to bend away from the upper sections of the bulkheads so the main longerons could be inserted later.

Time: 4 hours