Photogrammetry III

In 2016 I was starting to build a detailed understanding of all of the Vampire’s wooden structure. The exact build up of the structure at the tight little area between the aft of the Duct cut-out and Bulkhead 4 (the firewall) was unclear to me. The build is compound with the various laminates being built up in different directions – circumferentially around the cut-out, circumferentially around the fuselage, and with differing cover plies according to how much room was available. This gave rise to an exercise in determining the amount of detail that can be captured with VSFM in a portable 3D expression – meaning that I wanted to be able to study the structure when I wasn’t in the shed with the Vampire. The result was excellent! By this time I had become realistic about the computing power required to complete large photogrammetry tasks. I now had a workstation with an Nvidia K620 GPU. This made mole hills out of mountains!

Detail study: the left-hand Duct cut-out, Vampire A79-733

Detail study: the left-hand Duct cut-out, Vampire A79-733

My first jobs for 2017 were an entire detail shoot of the fuselage of A79-733 and a detail shoot of A79-175’s RH instrument panel in-situ. The purpose of these shoots is a true test of the potential use of this data in CAD.

3D cloud of points created from around 660 photographs of the fuselage pod of A79-733

3D cloud of points created from around 660 photographs of the fuselage pod of A79-733

Detail study: the right-hand instrument panel and surrounds in the cockpit of A79-175

Detail study: the right-hand instrument panel and surrounds in the cockpit of A79-175

Photogrammetry II

My next project was an initial pass through the interior of Camden Museum of Aviation’s GAF Lincoln Mk.30A cockpit/forward fuselage section. This is a large and complicated structure and I simply did not take enough photos to produce a point cloud that would get people excited! There were two issues with the result. Firstly, VSFM can run out of information to connect all photographs – simply, there are not enough photos to put everything together. The result is multiple reduced recreations that represent local features of the full object. Each point cloud, whether a successful result of the entire object, or of a fractured, is called a model. The result for the Lincoln was nine models.

Some of the separate models generated from the Lincoln photographs

Some of the separate models generated from the Lincoln photographs

Visiting Albury in 2015, I took a series of 52 photos of the interior of DC-2 A30-11 – the aircraft painted as Uiver. This was a rushed effort but I felt the result showed potential.

The cockpit of the Albury DC-2

The cockpit of the Albury DC-2

Photogrammetry I

Since 2014 I have been researching and trialling photogrammetry as an aid in rebuilding the fuselage of Vampire A79-733. My efforts have only been sporadic due to my usual lack of focus and other priorities.

My first photogrammetry used Autodesk 123D. I was also thinking about possibilities for 3D printing. Starting with something simple, I chose a TR-1936 controller because I wanted to make a mockup of a TR-1520 controller – the latter seems to be made of unobtanium. From a reverse-engineering point-of-view, this was not a particularly good idea; the boxes are very simple and the obvious method would be to get out the ruler and just measure up or even just cannibalise a 1936 unit. Starting with something simple was all that lay behind it. I had already done a fair bit of reading about photogrammetry so was aware of object characteristics that are unhelpful to the process. This simple test highlighted these issues. The controller I used was of very good condition and was very clean. The controller has plenty of reflective surfaces; the Perspex of the dial window, the nice fresh knob, the glossy lacquer over the ink mod markings and even the overall black paint. The basic photogrammetry process relies upon many unique features to triangulate upon. A uniform surface – the smooth black paint – is a ‘large’ expanse of nothing to triangulate. A glossy surface reflects and may just transfer ambient diffuse light to the camera lens or a reflection of something beyond in the area that surrounds the object. The Perspex of the channel dial may send light or a reflection of something beyond to the camera, or the camera may see the characters of the dial itself, or in one photograph, we might see a combination of both. Seeing different things from different angles ‘does not compute’. Depending on the software, it may present the initial result with holes or it may have some means of creating infill.

The TR-1936 controller with 123D was a disaster! Knowing the limitations, I then created a 123D project using a ‘Bug’ by artist Mark Brown. This was initially very successful, but then I made one mistake. Fatal. And in 123D there is no undo. I lost most of the job which had been very tedious. While I wanted to take the project  to completion, working on the cloud started to be a problem and I gave up out of frustration. 123D is targeted at 3D printing and has a strong infill capability. I quickly decided that 123D was not for my main project and went elsewhere.

123D result of Mark Brown's Xmas Drone (2004) using 28 photos

123D result of Mark Brown’s Xmas Drone (2004) using 28 photos

I had previously looked at VSFM by Changchang Wu, that has CMVS by Yasutaka Furukawa built in through the user interface, without making any real progress. This time I ran photo series of Mark Brown Bugs. The results were ordinary only, but I could see that this was because of the quality and quantity of photographs I used, and because of the plain white-wall background to the photos.

Sometimes I become impatient. This was one of those times. I decided to leap in the deep end. I took 100 photographs of the fuselage of Vampire A79-733. Without too much fuss – just some memory problems and 17+ hours of my business-type laptop grinding away – I got a an impressive outcome. See below.

Dense point cloud reconstruction of A79-733's fuselage using VSFM and CMVS

Dense point cloud reconstruction of A79-733’s fuselage using VSFM and CMVS

After that success, I created a point cloud of a Rolls-Royce Nene Mk.103 from 170 photos. My Laptop struggled a great deal from this load; VSFM stopping several times as it ran out of memory. This was not such a big deal as VSFM stores its work as it goes, so on starting a run again, it resumes processing from where it crashed.

Rolls-Royce Nene Mk.103

Rolls-Royce Nene Mk.103

I saw these runs as a way to learn to use the software and to see what it could do; to see what I needed to do to make it useful.

DAP Beaufighter IFF Mk.III

While trying to figure out if Camden Museum of Aviation’s Beaufighter should have the IFF system fitted, we were lucky to have actually located a photo of the aircraft while in active service. This is in the AWM collection: A8-186

Balikpapan, 22 Squadron

Balikpapan, 22 Squadron

While conducting research on this matter, I requested a couple of digital copies from the NAA. These are now available and make interesting reading…

Radar – Introduction of IFF Mk III Eqmt in SWPA

IFF Mk III Interrogation and Response Units

Contact me at nicko (a) (this site address) if you want to provide comments on anything on this site.

End of the Line

In August 2013 production of aircraft components at the old Hawker de Havilland Bankstown factory ended after 70 years. The first Mosquito came of the production line in mid 1943. Boeing Aerostructures Australia’s NSW facility was on the way to its closure in December of that year.

Ironically, the very last aircraft activity of any sort in B-Hangar, where the Mosquito final assembly line had been located, was the disassembly of Vampire T.22, XA167.

131 0946 XA167 sml

The original hangars (A, B and C) that made up the De Havilland Aircraft factory were built in 1942. Widely published are photographs of the Mosquito line at Bankstown, where the back of B Hangar (also ‘Building 12’) almost disappears in the distance. With an area in excess of 12000sq m, this is the largest of the buildings on the site. The hangar went on to house final assembly lines for the Vampire, Drover and Blackhawk. Recent news is that the hangar is being totally re-clad (to remove the asbestos) and divided into four. There has not been a tenant since Boeing Aerostructures Australia moved out of the hangar at the end of last year.

B Hangar

The Australian company De Havilland Aircraft was renamed Hawker de Havilland in 1962, as result of the rationalisation of the British Industry, and the company’s parent being Hawker Siddeley Group. After a couple of other changes of ownership (BTR and then Tenix), Boeing bought the company around the end of 2000. The next name change didn’t come until 2009 – to Boeing Aerostructures Australia. Production of aircraft components by the company continues in Fishermens Bend.

By chance, XA167 (painted as A79-642) was positioned by crane for disassembly at the very location of the original local Vampire production line. By chance, I say, as the location was chosen to suit the schedule for the remediation of the interior of the hangar.

(T.22 XA167 was in fact built in the UK. In its current incarnation it contains many components from Bankstown-built aircraft; details provided on the Vampires page.)

Syd Beck’s Military Museum – Sea Venom WZ904/N4-904

A DH-diversion of note at Syd’s museum is the Sea Venom FAW.53 N4-904. This aircraft was used for Ikara missile trials/testing. A couple of items of special equipment can be seen on the aircraft, including the mounting bracket for an Ikara fin that can be seen indicated in the photo below. I understand that the aim was to investigate vibration of the fin by filming it during flight, a camera being fitted in the Venom’s gun bay. The gun bay door was fitted with a transparency. The little piece of documentation I have found so far is a couple of pages in AP 4360C for Mod (RAN) 58, relating to attaching the fin to the port boom. The text mentions that Mod (RAN) 61 applies to fitting the fin to the starboard boom. It would be interesting to know more about these trials if anyone has more information.

 On the subject of Ikara trials, there is interesting information on the Adastra website.

Syd Beck’s Military Museum – Vampire A79-89

In October this year I visited Syd Beck’s Military Museum at Mareeba (50+ km from Cairns), Queensland. Apart from a great assortment of aircraft, military vehicles, engines, and artefacts from WWII, the collection includes Bankstown-built Vampire F.30, A79-89.

A79-89, c/n 4025, was built as an F.30, and being amongst the first 29 aircraft built at Bankstown, remained in the Mk.30 configuration into retirement. Having been received by the RAAF on 4th May, 1951, the aircraft served with 78 Wing, 2 OTU (for at least 3 periods over its 6 active years) , and ARDU. In early November 1955, the aircraft experienced a belly landing at Williamtown, NSW, after a flat tyre prevented the starboard gear from lowering. In the first half of 1956, the aircraft was fitted with an ejection seat at DHA, Bankstown. Like the other F.30 Vampires, A79-89 was retired from active service in 1957, and was received at Tocumwal, NSW, in September of that year. In August 1960, ’89 was received at the RSTT at Wagga, NSW, and allocated the Vampire instructional airframe number ’11’.

Syd told me how he purchased the aircraft from a scrap yard in Brisbane. The yard owners were going to assemble the aircraft and locate the aircraft as a prominent promotion for the business. The fuselage had always been stored inside, but the wings were stored outside. Since then, Syd has assembled the aircraft and always kept it under cover. The aircraft is generally in good condition, but is missing many small components, such as the pitot tube and its mount.

In the background of the photograph, you can see some of the structure of the igloo hangar. This WWII hangar was originally in Townsville where Syd and his family used to be located. He brought it up to Mareeba and has extensively refurbished the structure guaranteeing its future for at least a few more decades.

The Mystery of the Missing Generator

The configuration of the auxiliary gearbox that I have typically seen on FB.31s – in tech pubs and historical photographs (no opportunity yet to see any in the flesh) – includes mounting of the generator. Early and later configurations are shown below in extracts from AAP.828:

Above: Early configuration with vacuum pump. Generator is shown.

Below: Later configuration with vacuum pump deleted. Generator is shown.

Below: Other configuration with vacuum pump. Generator is not in the usual position; instead a bracket with pressure relief valve is attached at the location. The wreckage shown is from Vampire Mk.31 A79-536 which crashed at Pearce on 18th September, 1955.

Vampire F.30 A79-14 at the Camden Museum of Aviation has a similar gearbox that is partially installed – the gearbox has the bracket with pressure relief valve, and no sign of any generator!

So, what I want to know is:- WHERE IS THE GENERATOR on aircraft of this mod status?!

A New Dawn… and the Vampire F.30/FB.31 Fuel Gauge Panel

Well this is it. I have entered the ethereal world of blogging. Pleasingly, there is a real world behind it, and I am going to start by looking at an aspect of the Vampire F.30 and FB.31 cockpit – the fuel gauge panel. The single-seat Vampire instrument panels are largely standard parts across various marks, the fuel gauge panel being a good example. As such, the same panel was used in the early single-seaters and the late-service configuration. In the former, the panel carried five fuel gauges and the clock. In the latter, the panel carried just the five fuel gauges; the basic panel assembly is the same, so for the late configuration the clock hole was empty. (The clock was moved to where the film footage counter for the G.45 gun camera used to be.)

The basic panel was made from Tufnol and had two aluminium reinforcing angles riveted to the vertical edges. The panel also carried descriptive placards and wiring junction boxes.

The five fuel gauges are as follows (indicator values in gallons):

Description     Range/Capacity     Stores ID                        Smiths ID        Panel Location

Port Outer       0 – 57/65               G6A/1969 or /2588          1352FG          Lower Left

Port Inner      0 – 47/52               G6A/2039 or /2587          1351FG          Upper Left

Main               0 – 80/96               G6A/3661 or /2580          1350FG          Top Centre

Stbd Inner     0 – 47/52               G6A/2039 or /2587          1351FG          Upper Right

Stbd Outer      0 – 57/65               G6A/1969 or /2588          1352FG          Lower Right

4 Jan 2013: fix: gauges were wrong way round for inbd and outbd.