Talk:Dunne D.7

Dunne's names

In a first go at this page I've mostly drawn on the books by Goodhall & Tagg (G&T) and by Peter Lewis, together with the 1911 "Flight article The Dunne monoplane, 1911". There is some confusion about designations, i.e. the D numbers etc. Cf Talk:John William Dunne#Dunne aircraft for a more general debate on Dunne's aircraft identifications. The Flight article offers no name, but the two books agree that this was the D.6. They also agree that the later, lighter and smaller pair were the D.7 and D.7 bis. Only G&T talk about the glider and its powered development, which they call the Dunne-Capper machines. From the dates for testing the latter in G&T, 5-14 Jan 1911, it's likely that this is what Flight, 14 Jan 1911 http://www.flightglobal.com/pdfarchive/view/1911/1911%20-%200031.html calls "the Capper Greene-engined machine", though they don't say monoplane or biplane.

To try to understand this better I got from the Science Museum, London (SM) a description written by Dunne in 1928 of some of his aircraft. The SM person was very quick and helpful. Part of this list appears in http://www.flightglobal.com/pdfarchive/view/1955/1955%20-%200854.html, but the full m/s includes several of the monoplanes. It's not necessarily a complete list, for JWD had sent the SM data and photos of aircraft of which he thought they might want to make a model (a model D.8 remains on display) and his summary covers only those aircraft. There is no D.9 or D.10, for example. Anyway, on the monoplanes he writes:

"D.6 was the monoplane fitted with the first type of undercarriage tried. It was taxied about at Salisbury Plain [Larkhill], but failed to lift. Built 1910."

This description, place and time seem to suggest this machine is what T&G call the Dunne-Capper monoplane. It is not the 1911 aircraft called the D.6 by both G&T and PL.

"D.7 was the same monoplane lightened, and with a newer chassis. Fitted with a 30 H.P. Green it was flown very successfully by Mr Dunne at Eastchurch in 1911. After wards it was fitted with a 50 Gnome and was flown by Mr Dunne at both Eastchurch and Salisbury Plain. It proved rather difficult to land." In the margin alongside this para he added, presumably with respect to a photo "note torque balancing control flap."

Apart from the engine output, this sounds in time and place and flights like what PL and G&T call the D.6. 30 hp Green's existed, but the later writers say 60 hp. So at this point the historians and Dunne disagree on the name.: Dunne's D.6 did not fly. The aircraft with the 50 hp Gnome sounds like G&T's and PL's D.7, though: PL's photo from the March 1911 Aero Show shows a radial or rotary engine. So we are back to rough agreement again, except that the historians are saying the new engine was accompanied by lightening and a shorter span and a change of D. number. Dunne does not mention the Aero Show.

There is a flap visible in an image of what G&T call the D.7 bis (see below), though they say it is "centrally mounted to improve pitch control." It's hard to tell from the photo if it is centrally mounted or offset for torque control. There is also an image at http://earlyaviators.com/edunne.htm, labelled D.7 which has a clearly asymmetric (port-side) flap of different aspect ratio to that on the D.7 bis which could well be Dunne's torque flap. There is also a 4- bladed prop, which is not mentioned in any text I've read.

To confuse things further, G&T caption photos from the Flight 1911 article on what G&T call the D.6, as the D.7. This is an accident, as the caption says "at the Aero Show" which sounds as if they meant to put the photo that appears in PL here.

"D.7 bis was the same type of machine with generally improved performance, and fitted with a 70 Gnome. It was flown by Mr Dunne very successfully at Villacoubley near Paris in 1912 or 1913. A fast climbing machine (for those times)."

There seem to be no incompatibilities here with the accounts of G&T and PL apart, perhaps from the torque flap.

So the main issues seem to be: was the Dunne-Capper the D.6, and just when in the development process did the D.6 become the D.7?

I guess any appeal to this document would be regarded as OR and that we must stick to our secondary sources who may have unearthed more info on these 1910-13 aircraft in 1962 and 2001 than Dunne recalled in 1928, but it would be good to know why they call the D.6 is named by Dunne as the D.7.--TSRL (talk) 07:29, 13 May 2010 (UTC)

If a document is available to the public for inspection, then I don't see why citing it should be OR. just be warned that the typed transcript contains a potentially significant error, which becomes apparent when you examine Dunne's original handwritten note.

The confusion between D.6 and D.7 goes back at least to Lewis; British Aircraft 1809-1914, Putnam, 1962. His account of the Dunne machines is riddled with errors. — Cheers, Steelpillow (Talk) 20:37, 30 July 2017 (UTC)

Goodall and Tagg

I am concerned that the material apparently sourced from Goodall and Tagg's book "British Aircraft before the Great War" (Schiffer) may not be reliable, however I do not have access to a copy. I suspect that either an article editor has taken liberties or Goodall and Tagg have. The account of the monoplane development differs substantially from other RS. Percy Walker extensively researched the Army archives and related material when he wrote his official history, "Early Aviation at Farnborough, Volume II: The First Aeroplanes." (Macdonald 1974). He makes no mention of any monoplane aircraft before the D.6, and in particular none was present during either set of trials at Blair Atholl. On the first visit, the D.1 minus its engines was used for the gliding trials and on the second, the D.3 biplane was used. Neither Jane's (1913) nor Dunne's own letter to the Science Museum (reproduced in part in Flight 17 June 1955 p. 852 [1]) makes any mention. OTOH Dunne's teenage assistant at the Balloon Factory, Percy Gurr, made a personal recollection, which was published in Flight ("Pioneers Remember", 1 July 1955, pp. 9-12 [2][3]), and does mention such a "glider (monoplane)" being taken up. But Gurr mentions only one visit, also appearing to confuse what happened on which visit. One may certainly take Walker as a reliable secondary source, and perhaps Jane as well. Gurr's recollection is a lone tertiary source, conflicting with all others and exhibiting known errors, i.e. I do not think we can treat it as reliable. There is a similar lack of reference to any "Dunne-Capper monoplane" in any reliable sources I have ever found. What then of the references to such monoplanes in the present article and their attribution to Goodall and Tagg?

As a further thought on Goodall and Tagg's reliability, here is what I believe to be their entry on the D.9 (copied from a copyvio site so no link I'm afraid):

"DUNNE D.9 monoplane (Also referred to as the James monoplane)

"This was a tailless pusher design of almost delta wing form. It was a single-seater with a protective cage above the cockpit, serving also as an anchorage for the bracing wires. The wheels on the twin skid undercarriage were covered by fairings. The power plant was a 35hp Levis five-cylinder inline two-stroke engine designed by H. Newey, mounted inverted in the nose, and driving the propeller by extension shaft.

"Dunne was assisted by C.R. Fairey with the stressing and the machine was constructed in 1913 for a Mr. James by Levis Ltd. of Stechford, Warwickshire, motorcycle manufacturers. The name 'Leonie' and the initials 'AB', probably of Arthur Butterfield, one of the directors of Levis, were painted on the wheel covers.

"The machine was wrecked on its first attempt at flight by hitting an obstruction on a playing field at Castle Bromwich, forestalling the proposal to fit floats for later trials on Edgbaston Reservoir."

This conflicts with the account of the D.9 given in Jane's (1913), which records it as a biplane of which 5 examples were under construction at the time. I believe that it also conflicts with the account of Lewis in his British Aircraft 1809-1914 (Putnam), where he at least identified the D.9 and the James Monoplane as distinct types. G&T appear to conflate the two designs, attributing known stories about either to the same aircraft. Close inspection of the only published photograph of the James machine also suggest to me that the "wheel cover" remarked on by Goodall and Tagg is in fact anything but: the lettering shows clearly that it is tipped on its side and the straight side should be vertical - it is more likely a tail fin yet to be fitted, as the usual Dunne wingtips are lacking. Such an elementary and obvious howler must surely cast doubt on the rest of Goodall and Tagg's writings on these obscure types.

So I for one am not prepared to take the present state of the article as reliably sourced. But is it down to misleading editing, are Goodall and Tagg at fault, or is there in fact reliable evidence of one or both of these mysterious monoplanes? — Cheers, Steelpillow (Talk) 09:59, 28 March 2014 (UTC)

[Update]: Further material reputedly from Goodall and Tagg:

"DUNNE-CAPPER monoplane glider

"As early as 1905 Dunne had made a model of a monoplane, the design of which was submitted to the War Office and rejected. A full size glider version of this was made at Farnborough in 1907 under Col. Capper's authority. It is believed to have been tested at Blair Atholl, unsuccessfully by Capper, at the end of August during the first official expedition.

"The glider was a parasol monoplane with swept wing and down turned wingtips, which was mounted on a structure of two A-frames, joined by longitudinal members, on which the pilot was supported by his arms, control being effected by weight shift.

"DUNNE-CAPPER monoplane

"When designing his early monoplane, Dunne required a 10-12hp engine, but nothing of suitable weight was available, consequently work proceeded on the machine as the glider previously referred to.

"It was not until 5 January 1911 that Capper's monoplane with Green engine was reported undergoing tests on Salisbury Plain (Larkhill) handled by Lt. Cammell. In the week ending 14 January further tests were carried out, in which Col. Capper participated. The machine could not be made to lift and Capper decided that further changes were required.

"In its new form the fuselage consisted of three A-frames, at the lower ends of which, a four wheeled undercarriage and twin skids were fitted. A third skid was fitted forward of these. The pilot and engine were mounted on a floor formed on the crossbars of the A-frames, with a radiator mounted outboard on the port side. The parasol wing, which was attached at the top of the A-frames, was well braced to these, and by additional cables, to three kingposts.

"Parts from the glider, probably the complete wing, were reported to have been used in its construction, which was largely the work of C.R. Fairey and was carried out at Larkhill."

The description of the glider appears to mix three different types. The 1907 glider which Capper flew (and crashed), and of which Flight published photographs in 1910 [4][5], was the D.1 biplane before its engine was fitted. The dangly-legs gilder was the D.3 of the 1908 trip. The A-frame monoplane is similar to the powered type discussed below and may or may not be the same airframe.

The Dunne-Capper monoplane is more interesting - the copyvio site shows two photos which are clearly not the monoplane depicted in Flight, having a massive A-frame fuselage with six wheels. What would it be doing at Larkhill - was Capper hiding it from Dunne and the Syndicate who were based at Eastchurch? Was it a formal military evaluation? Does this craft in fact have anything to do with Dunne? Was it even the D.6, with only the D.7 captured by Flight? What was Goodall and Tagg's source? I have seen a history of aviation at Larkhill published, is there anything in there about it? — Cheers, Steelpillow (Talk) 10:57, 28 March 2014 (UTC)

[Update 2] More research, more conflicting and inconsistent sources. The Smithsonian Directory of Airplanes lists just three Dunne monoplanes: the D.6, the D.7 Auto Safety and the D.7bis.[6]. A Dunne monoplane was exhibited at Olympia in 1911. Goodall and Tagg appear to record the Dunne-Capper monoplane and the D.7 Auto-Safety as different designs. Capper is variously said to have ordered both the Dunne-Capper monoplane and the D.7 Auto-Safety, and both are claimed by different sources to have been exhibited at Olympia. I find hard to believe that Capper ordered two Dunne monoplanes at much the same time, it seems more credible that these are the same aircraft. Photographs show differing fuselage frames: a squarish version and an A-frame. There is a suggestion that the craft was at one point modified, which would explain this fact nicely. Alternatively, two variants of the D.7 may have been constructed (one basic and one Auto Safety) but that conflicts with the Smithsonian list. Lacking any RS that Capper bought two monoplanes or the Smithsonian has missed something, I think we can safely ignore Goodall and Tagg, and treat the Dunne-Capper monoplane as the D.7. It would be good to know more about that modification than G&T provide. — Cheers, Steelpillow (Talk) 14:10, 28 March 2014 (UTC)

[Update 3] Since writing the above, the Science Museum has acquired Dunne's own professional papers for its archive. I have gone through the aviation material and it is crystal clear that Goodall & Tagg have not only been badly misled by Penrose, who himself was misled by Gurr, but that they have added their own interpretations as "facts". For example the "stability" flap is in fact a torque flap to counter the powerful Gnome engine, as other sources have also stated. They make an even worse dog's breakfast of the D.9, which is also described more accurately in other sources, such as Lewis. Even without waiting for the archive material to be published, I think we have enough evidence now to write off Goodall and Tagg as a reliable source for any Dunne machine. Does anybody have a problem with this? — Cheers, Steelpillow (Talk) 12:56, 6 December 2016 (UTC)

Just in case you though nobody was watching! I would agree that Goodall and Tagg appear to have made up some stuff compared with other sources. MilborneOne (talk) 20:43, 6 December 2016 (UTC)

OK, I have now removed the worst of their blunders and all the cites. — Cheers, Steelpillow (Talk) 20:28, 29 July 2017 (UTC)

Page move

This article needs moving to Dunne D.7, which is currently a redirect. The D.6 was a single machine which never flew. Several examples of the D.7 and D.7bis were built and all flew. The move needs an Admin, which I will request unless a consensus not to move is established here. — Cheers, Steelpillow (Talk) 20:27, 29 July 2017 (UTC)