- fill in front MG nose ports - fill in existing Ventrua windows - fill in edges of former bomb bay - fill in turret aperture - cut new cabin windows - new nose freight door and main cabin door - build up lower fuselage behind ventral gun - cut off fuselage tailcone and build replacement - relocate tailwheel - make new engine nacelles (or pinch from a kit with similar engine) and exhausts - make new main landing gear faring - remodel the rear cockpit wall
What have I missed?
Last Edit: Jul 12, 2018 20:42:02 GMT 12 by 30sqnatc
Initially I thought the same about Lodestar having Hudson wings but reading up on model conversions others have done they had to do extensive work on Hudson wings basically turning them into Ventura wings. Definitely the Lodestar and Ventura wingspans are identical. I've yet to fully understand what changes are required to the nacelles with the 'Hudson' engines. Definitely the props are further aft closer to the cockpit on Lodestar compared with Ventura.
Post by markrogers on Jul 13, 2018 14:06:20 GMT 12
I remember many years ago reading an article with pictures in a modelling magazine that detailed a conversion of the Airfix 1:72 Hudson into a Lodestar, using plastic card and filler and lots of sanding. The finished model was absolutely excellent. The same thing could be done with the 1:48 Hudson. Some Lodestars had a straight trailing edge like the MOTAT one for example.
Converting a Hudson to a Lodestar would be a major job, and as Lodestars were pretty common in the 1950s, why would anyone bother to undertake such a job? So far as I know there was only one "Hudstar" in the USA, produced by Rausch Aviation, who grafted the longer rear fuselage of a Lodestar (with the raised tailplane) onto a Hudson (actually an AT-18), so I don't think we can say that "a load of Hudsons" were converted to Lodestars. However many Lodestars had their wings "modified" so as to appear to have Hudson wings, but this was not a major mod as all that had to be done was to remove what were known as the traiing edge "extensions". These "extensions" were introduced on the production line to new Lodestars in about 1940, to solve a design problem called "elevator nibble", the symptoms of which are very briefly described in Rene Francillion's Putnam book "Lockheed Aircraft since 1913" (my example published 1987), page 189. Trials with three modified Lockheed 14s (otherwise known as Super Electras) in early 1940 "revealed that the Lodestar (Lockheed 18) was prone to 'elevator nibble', which caused its controls to oscillate back and forth while the aircraft was in flight. Initial attempts at curing the problem by splitting the elevators and adding servo tabs failed to have the desired result. Partial improvement was achieved by raising the tailplane by one foot (30.5cm), with ultimate solution being provided by the addition of a trailing edge extension to the wing. Together these modifications took the tail surfaces out of the wing turbulence, and the Lodestar successfully completed its trials programme to receive its Approved Type Certificate on 30th March 1940. The type entered service in March 1940 with Mid-Continent Airlines." Thus all production civil Lodestars, as well as all military C-60s, etc, along with all Venturas were delivered with the trailing edge extensions, although it seems some American aero-engineering firms in the 1950s took to modifying various Lodestars (and some Hudsons and Venturas) into corporate aircraft, some of which were capable of quite high performances. It was probably one of these firms that found it was possible to remove the wing extensions entirely, perhaps also adding to top-end performance, although how this was done is still a mystery to me. However it seems likely that by some cunning modifications to the elevator control circuits it may have been able to get similar final results. It is possible that the true story might have been published in one of the many American aviation publications of that decade, and they would also be described in the mass of technical literature which attached itself to each approved aircraft type certificate. Several (most?) of the second-hand Lodestars imported into NZ in the late 1950s and 60s from the USA for conversion to the topdressing role had these modifications incorporated on arrival. My ten cents worth. David D
Post by denysjones on Jul 16, 2018 11:15:36 GMT 12
I'm not sure I can provide too much insight here as I've only ever been involved with the Hudson.
I've had a look at the parts books for the Hudson, Lodestar, and Ventura that we have at Ferrymead. The illustrations of the wing group in the Hudson and Lodestar look identical but of course the P/Ns are different (Hudson wing is 70271, Lodestar 73681 and Ventura 19009 each with L or R suffix as appropriate).
The Lodestar manual we have shows a straight trailing edge to the flap bay identical to the Hudson not the kinked style of the Ventura. However the parts list shows two different numbers for the centre sections namely 50137 and 50173-500 which are annotated as Commercial and Conversion respectively which suggests some sort of option to me. (Its interesting that the centre sections have the same P/N left and right when structurally they are handed side to side.)
The other clue to the idea of an option thing comes from the Ventura manual which shows a separate item as the kinked trailing edge.
As to the interchangeability of outer wings all I can say is that I've always been led to believe that Hudson and Lodestar ones fit one another. MoTaTs Ventura has Lodestar wings fitted but difference in structure required the fabrication of attachment adaptors. Queensland Air Museum are going down the same path with their Ventura using Lodestar wings from the US and a Hudson wing from us.
Last Edit: Jul 16, 2018 11:19:31 GMT 12 by denysjones
Denys, Many thanks for posting the above illustrations from the Lockheed maintenance/assembly manual, and the quoted part numbers. Incidentally, as pointed out earlier it can clearly be seen that the "trailing edge extensions" are just that - I think they were riveted (or bolted?) to the trailing edge and I presume helped to deflect the slipstream coming over and under the wing surfaces further downwards as they moved to the rear, a little lower than without the extensions, thus helping to cure the annoying "nibbling".
Hudson wings could probably fit straight onto a Lodestar or a Ventura (perhaps even a Harpoon?) but I doubt that these would be strong enough to be certified as fit for flying. Although the civil Lockheed 14 and Hudson were operated at much lower maximum weights (in region of 17,500 for civil 14, 18,500 to 22,360 for Hudsons), civil Lodestars were cleared for weights from 18 - 19,000 pounds (21,000 as a military C-60). The later Venturas operated from 26,000 to 34,000 pounds, and up to 36,000 for the PV-2. At least one of the military max weights quoted here seems rather heavy to me, the 34,000 pounds for the PV-1 Ventura possibly being a discretionary maximum in extreme operational conditions. The RNZAF never operated theirs at this sort of weight. However the point I am trying to make here is that just because a wing (centre section and/or extension planes) can be physically bolted and/or riveted onto various similar aircraft, most would be outright prohibited from flying for very good reasons. Also something that has not been pointed out previously is that there were two types of landing flaps fitted to PV-1s, the "early" type (probably dating to the earlier RAF Venturas with lower max weights) and the "later" type, which were presumably redesigned in detail so as to confer greater strength, although they looked superficially very similar. Presume this change was brought about by the higher operating weights of the later Venturas which would have had the effect of considerably increasing their approach and landing speeds, depending on actual landing weight of course. I know that there seemed to be a rash of RNZAF PV-1s having their flaps modified or changed in mid-1944 at Espiritu Santo for reasons unstated, but possibly related to this problem. However the aerodynamic forces acting on the primary structure of a heavy operational PV-1 in the forward area which had become involved in a scrap with Japanese fighters could be very great, subjecting its structure to proportionally much higher stresses than a civilian Lodestar cruising along in level flight with a load of happy passengers and their baggage. This weight difference could be up to 10,000 pounds greater in favour of the Ventura, although borne on identically sized wings to the Lodestar. Anybody else have other ideas on these questions?
A quick read of the contemporary Boeing P-8 thread gives an interesting parallel commentary on the building of this new-age aircraft, and like the Ventura, the Boeing aircraft has had to go through a similar programme of redesigning to convert the civilian original (737-800) to meet the military requirements. This includes much strengthening of the airframe to suit the completely different environment (including alternate low altitude capabilities) and much heavier demands on the electrical supply to operate the extensive installed equipment. David D
Converting a Hudson to a Lodestar would be a major job, and as Lodestars were pretty common in the 1950s, why would anyone bother to undertake such a job? So far as I know there was only one "Hudstar" in the USA, produced by Rausch Aviation, who grafted the longer rear fuselage of a Lodestar (with the raised tailplane) onto a Hudson (actually an AT-18), so I don't think we can say that "a load of Hudsons" were converted to Lodestars.
About six to eight months ago I found an article online in a digitised archive of an old US magazine, and cannot recall what the title of the magazine was now sadly, and I downloaded he article as a pdf I think, but I cannot find it anywhere now after my upgrade to Windows 10. It was all about a company in the USA in the late 1940's that was buying up surplus Hudsons from around the world and converting them to Lodestars as there was an appetite for Lodestars as business planes.
Apart from the one infamous "Hudstar", there seems to be no real evidence that there were any other "Hudson to Lodestar" conversions completed anywhere in the world. There MAY have been the odd one here and there, but why not start with a standard Lodestar in the first place, with some hundreds coming onto the civilian market all around the world, but particularly in the USA where the majority were located. Pretty well all the military forces that operated Lodestars (either impressed civil models, or the USAAF C-60s) disposed of these aircraft shortly after 1945. Some Hudsons were civilianised too of course, but never in large numbers, mainly in Canada, Australia, and even one in NZ! Probably also a small number in USA (mostly ex trainer-type Hudsons). David D
Post by Dave Homewood on Jul 17, 2018 8:48:33 GMT 12
David, the one that Steve Searle bought from the USA and had planned to take to Australia a little while before he died was said to be an ex-Hudson that had been converted to a Lodestar, and he was planning to convert it back to Hudson status. This was reported in the aviation media at the time, about 7 years ago I guess. I have often wondered what happened to that aircraft after he died.
I wonder if all the confusion regarding Hudsons, Lodestars and "Hudstars" comes about because Hudsons were converted to passenger use, losing most of their war-like appendages in the process, including their fighting plumage. Even the RNZAF, when converting Hudsons to passenger duties, had a different designation for the converted models. I can recall some years back reading an article talking about converting swords into ploughshares, and the Hudson conversions were mentioned in that. Like Dave, I can't recall where I read that, but, unlike Dave, I have an excuse - old age! Mind you, the other day I found a photo of a Hudson fuselage converted to a caravan here in NZ. When I get time, I'll scan and post it.