Douglas F3D Skyknight 20 mm Cannon Installation

 

Thanks to Smellybeard (obviously a nom de plume), I know more about the this subject than I did a few days ago. It began when he asked for confirmation that at least two of the 20 mm cannons were located in the nose wheel well, a detail that hadn't occurred to me but obviously necessary from the front view.

Thanks to his research and the files of my F3D subject-matter expert, Paul Bless, I have reappeared out of this particular rabbit hole with information new to me if not to you.

 

First, text from the Erection and Maintenance Manual:

And an illustration:

Note that the cannon are staggered by the width of the ammunition feeds and fire into blast tubes. This isn't obvious from any pictures of the nose wheel well because the cannons and blast tubes have been removed. See links provided by Smellybeard: http://nabe3saviation.web.fc2.com/images3/twaf3-10.jpg and https://media.net-maquettes.com/2024/08/Douglas-TF-10B-Skyknight-72.webp . In the latter one, he notes that there is a mount on each side of the well that corresponds with detail B in the illustration above. He also wonders if the landing light was original equipment because of its potential interference with the left hand cannon.

However, an opening in the aft end of the nose landing gear door is usually still present: this was where the cartridge cases and clips were dumped overboard (the corresponding ones for the outboard cannons were located farther aft under the fuselage).

 

The nose gear bay opening is not as wide as it appears from the front based on the location of the nose landing gear doors because they are mounted on goose-neck hinges.

 But the opening is also much longer than it needs to be, apparently to provide for access to the ammunition feed to the cannons.

 

 

In an F3D nose wheel well I looked into, roughly the aft half of the opening was closed off by a panel, but at the moment I don't know if that was original or something added when the Skyknight was prepared for display.