As with most designs from that era, the Aurora features a tank bay with limited access behind the wing-attachment former. Additionally, the nose retract is mounted directly to the tank floor. This configuration restricts access to several critical components that should remain easily serviceable for troubleshooting or maintenance.

To address this, I decided to make the tank floor removable. Because the tank floor is molded into the fiberglass fuselage, it had to be cut out. Instead of reusing the removed fiberglass section, I opted to fabricate a carbon-fiber plate of appropriate thickness—stiff and strong enough to serve both as the new tank floor and to withstand the loads transmitted by the nose retract during landings.

I then planned the layout of the removable floor panel so the selected Sullivan 14 oz slant tank could be extracted from behind and from below the tank bay. In terms of the door length, I also needed to account for fastening hardware. I chose to fasten the floor using 6-32 bolts and matching blind nuts installed on hardwood blocks and glued to the tank walls.





At this point, two issues emerged regarding the nose retract. The first concern was the retract pivot point. Because the Aurora has a belly pan, this pivot point sits a couple of inches above the outline of the belly pan. As a result, it makes a significant difference whether the retract mounting plate is positioned above or below the pivot point.

In this case, the electric retract came with a plastic mounting plate located below the pivot axis. With this configuration, the retract would have to be recessed into the tank floor, and a wheel bay cavity would also be required inside the fuel tank floor to accommodate the geometry.

I addressed this by noting that the retract also included threaded inserts on its upper side. I initially assumed I could simply remove the bottom plate and relocate it on top; however, the hole spacing did not match. To resolve this, I fabricated a new carbon fiber mounting plate with the correct hole spacing, allowing the retract to be mounted above the pivot point instead. First issue solved.


Original plastic retract mounting plate



Original retract plate position





Carbon fiber made mounting plate





Final retract plate position


However, placing the retract—with the new mounting plate—flush under the tank floor left only 11 cm between the bottom of the retract and the ground. Accounting for geometry, this meant the strut could be no longer than about 7.5 cm:

• 1 cm for the steering arm height
• 2.54 cm wheel radius (1" radius wheel per the plans)

Since the shortest aluminum nose struts available on the market were 9.5 cm, the nose gear stance would end up roughly 2 cm taller than the main gear stance, producing an incorrect wing incidence in takeoffs. The alternative was to recess the retract into the tank floor again, reintroducing the same geometry problem.

Instead, I opted for a better solution: raise the tank floor door (this also brought an additional benefit that I will explain later.)

Because the Sullivan tank was shorter in height than the original MK fuel tank, raising the floor proved to be an even better option. Ultimately, I had about 1.8 cm of vertical tolerance to raise the tank floor—an acceptable amount considering the spring-damped struts will compress some millimeters under the aircraft weight.

The results are shown in the photos. I also clad the external walls created by the raised tank floor in 0.5 mm carbon fiber sheet, both to maintain a clean appearance and to provide fuel resistance to the area.