Terrific post Mark! 🙂

(Paul have you visually confirmed A20-13 is actually a CA-1, as had heard Tom King has simply repainted a much later example to represent that early identity)

I haven’t been to Port Moresby at all, let alone to have a look in the Museum there. Unfortunately, the collapse of the airline I was working for in 2001 stole that opportunity away. 🙁
I can only go by what other people have told me and from what I remember (fraught, I know!!) from photos I have seen of it in much happier times, as it has deteriorated significantly now.

The other idea I have had mulling over in amongst the detritus in my head, is possibility of any wrecks/remains in either South Africa or Zimbabwe. From memory, a lot of the Harvard Mk 1s were sent there as a part of the ETS.

Either way, to me, the project would certainly be possible, it just needs someone with the time, ca$h and madness to do it. I’ve got the madness, but not the other two prerequisites….:D

First catch your Wirraway, of course

Ah, but not all Wirraways are same! 🙂
There are six different models of the Wirraway – the CA-1, CA-3, CA-5, CA-7, CA-9 and the CA-16. The CA-1 fuselage frame is the closest to the Harvard Mk 1. The CA-3 and subsequent forward fuselage frames have larger tube diameters, especially the longeron tubes. I know this because I have physically tried to offer up a T-6 up lock support fitting and they do not fit. Also, the later fuselage alloy fittings do not fit the early CA-1 frames for the same reason. The CA-16’s were a combination new build airframes and modified earlier models, incorporating strengthening of the wings and centre section for the carriage of bombs and the addition of dive brakes. The dive brake setup was incredibly dangerous and ended up being de-activated in service. It relied on the pilot to stop the normal flap extension prior to the last portion of travel of the flap actuator which “popped” the dive brakes. One can imagine if you are busy in a crowded circuit, a momentary lapse of attention during operation of the flaps could having alarming, and quite often, fatal consequences.
So, back to our hypothetical Harvard Mk 1 build. I know of only three surviving CA-1 frames. Two airframes are pretty well complete and are in museums – one in Port Moresby and the other at Moorabin. The only other frame I am aware of is bare.
Nonetheless, I would still like to see a Harvard Mk 1 brought back to life. 🙂
*Now where are my winning lotto tickets….*

Dunno wot the aeroplane is, but I want the engine – an Armstrong Siddeley Genet Major! 🙂

With the two different scales on the face, the very fine needle and graduations, I’m guessing that this is more likely to used for calibrating altimeters, rather than being fitted to an aircraft.

Almost all radial engines have some form of impeller or supercharger, initially primarily to improve mixture distribution to all the cylinders. One notable engine with mixture distribution problems is the Jacobs R-755, hence they were known as the “Shaky Jakes”. Radial Engines Ltd in Oklahoma have produced a fuel injection system for this engine to resolve this problem.
I would not be surprised if the conversion of the R-1340 Wasp from the “C” to “SC” was due to the change in step up ratio of the blower drive and therefore changing the function of the blower from merely improving mixture distribution to also increasing power, both at sea level and altitude.

The North American Aviation part number system is a little different, but once understood, is quite simple. The dash number, eg -31105 is the basic number for the item in the aeroplane and can be broken down even further by, IIRC, the first number relating to the grouping of the different major assemblies. For example -3xxxx is the fuselage group, -2xxxx is the empennage group, -1xxxx is the wing group, etc. As related above, the prefix numbers (numbers before the dash) are the aeroplane model number. So, it is possible for the dash number to be the same, because it will be the same item, eg forward fuselage frame, but the actual parts will be different due to a different model number. I did get into this quite heavily at one stage, trying figure out what was interchangeable between the Wirraway and the much later AT-6/SNJ series aircraft and that was not much at all…
I do think it is a terrible shame that none of the early RAF Harvard Mk 1s have survived, as they did play an important part in the Empire Training Scheme. However, I reckon if I could get hold of the drawings for the BC-1 or BT-9 and compared them with a Yale or SNJ-2 fuselage frame, I don’t think I would find too many differences. In fact, if I won the lotto, I would like to have a crack at bringing a Harvard Mk 1 back to life. 🙂

The SNJ-2 did reputedly have a 6in wider centre-section to allow for an additional fuel pump: although an external bump covering this pump can be seen in photos I’ve not seen other evidence for this wider c/s.

The SNJ-2 has a quite different wing centre section, in that it is “wet”, ie it does not have separate, removable, fuel cells like its brethren.

Some of you guys have no sense of adventure and have allowed myths and legends to persist. Delmar Benjamin flew his for some years on the American airshow circuit and put in some fairly serious hours in the machine without too much trouble. Kermit Weeks is not silly either and displays a professional approach to aviating. I reckon it is terrific these guys (and others) have gone to so much trouble to recreate these wonderful machines, to keep the knowledge alive and to dispel some of the tall stories.