It’s all in the detail

Hi All,

In December I had a very productive last minute trip to Holland to inspect and sort the recovered wreckage from Hawker Typhoon MN954. This is the aircraft that I watched the recovery of back in the spring of 2024. More to come on this.

I've been working away on the forward mono section as our spar fittings slowly make their way to completion. My fucus has been on all of the smaller frames, stiffeners, doors etc that are fitted to the most forward bay area.

Within this small section, there have been quite a few mysteries that eat up time to resolve properly, many of these have been encountered on the flare tube door and its frame, as well as the wireless door and frame; in both cases we have no drawings!

I'm nearing completion on both of these tasks right now, but thought you would all love to see some of what has been happening.

First, the flare tube door. I'm not sure if the flare tube was ever actually used operationally, I still need to do some research on this. This was a landing flare that could be fired from the cockpit by the pilot, the tube faced downwards and was fitted behind the pilots seat. To operate the flare, the pilot had a control to first open a small door, this door and frame remained in production right through to the final aircraft ordered. As mentioned, there are no drawings for this area, but we were very fortunate to have a salvaged door provided to us by our friend Pierre Ben of France (Typhoon JP600), and with this we were able to make a new one.

As you can see, the parts have all been formed in "0" condition, and will be off to our friends at Pyrotek Aerospace for heat treatment soon. I started building this door thinking it would be a nice change to do a fairly basic part, however it took me far too much time and frustration to get the pesky mitered corners correct! Quite a bit of tooling manufacture and modification was needed to succeed with this little guy.

Another little job was making the stringer "caps" that Hawker used to tie the stringers to the aft side of frame "A". Special tooling had to be made for these as well. I made a slight change to these from what Hawker designed. When looking at surviving parts, I found the the holes where the caps attach to the stringers were all below minimum edge distance. To fix this, I added the short flanges to the outer edge of the cap so they fully nest within the stringer profile. I've started to install these now as skin panels are removed and reinstalled.

Another interesting bit (again in need of special tooling and forms), is the mount for the Beam Approach Antenna. This antenna is very carefully located, and thankfully we had the required information. Due to the shape of the skin and the need for a flat platform for the antenna, Hawker pressed a flat section in the skin for the mount. This pressed section was also reinforced, and because of the proximity of the stringer sections, it also required a packing piece. All three of these parts (skin, doubler and packing) required the pressed shape so they could be correctly nested together.

I will post later on this little bugger, the final shape is horrible and I had a very difficult time keeping it as designed. More to come on that.

The wireless door frame is a big one, there is no information on this in the drawings, so we've been working with the Team at the KF Aero Center for Excellence to find missing details. This is tricky too, as their Tempest has had some changes in this structure. Fortunately, the recovery of Typhoon MN954 in Holland, and the pictures taken at the time, also provided significant help.

I was able to find the frame profile in the Hawker standards which was a big help, but it is like much of the parts in that they designed it with bend radii smaller than acceptable for bending in treated material, so all parts need to be made from soft material and heat treated. The tight nature of the frame profile meant for a lot of tool modification and testing to find the best procedure to form it. After much trial and error, I found a good recipe and was able to form the blanks for all 4 sides of the frame. From here, each part needed to be fit, trimmed and formed to the correct profile of the fuselage.

I am still finishing this section up, but the end is near!

Hawker Typhoon MN954

Monocoque Update