Wings of Intent: De Havilland D.H.53 Hummingbird

(this is the building article, for the finished model go here:
http://wingsofintent.blogspot.com/2017/02/de-havilland-dh53-humming-bird-lympne.html

The lightplane concept was visited on the post of the Parnall Pixie:

http://wingsofintent.blogspot.com/2017/01/parnall-pixie-scratchbuilt-172nd-scale.html

The De Havilland D.H.53 Humming-bird is one of such machines. It was contemporary to the Pixie and a small number of them were sold to particulars and the RAF. Power plants varied, and the first model had a Douglas of 750cc. According to information found on the Net, one plane ended up in Chile, two in Australia and one in Canada.

Choroszy released a resin kit of this plane, although, alas (surprise-surprise) in military guise.

The plane had a span of 30"1' (9.17 meters) with almost constant chord, but differential airfoil, which varied in thickness along the span.

The usual scratchbuilding techniques you may have seen on this blog were employed, to ensure a satisfying measure of accuracy and a bonafide reproduction. A resin prop cast by Matías Hagen (thanks Matías!) from Argentina was used, with resin wheels from the spares bin and adapted resin cylinders again from Matías. Care must be exercised in replicating the particular change in airfoil section, thin at the root and wingtip and thick in the middle, a detail often obviated by modelers.

A model of the Parnall Pixie, a plane -as said above- designed under the same concept and flown contemporarily to the D.H.53, is being built in parallel. Originally it even had the same Douglas 750cc engine.

A number of different decorations can be seen in photos, many of them most likely in aluminium dope, sometimes with the fuselage in a darker color, and in some photos it's shown with what seems wings of clear doped linen, with certain translucency.

I selected a subject (G-EBHZ) based on a very good photo I found on the Net, that had the same scheme as the restored machine that used to fly in England (G-EBHX), until unfortunately had a fatal crash in 2012. The machine chosen, G-EBHZ, changed schemes, and I was fortunate enough to find on the Net photos of them. One is an all-aluminium scheme with the logo of the Seven Aeroplane Club, an AC with seven feathers (thanks, Sönke). Another is blue and silver, like as said the machine restored.

Be sure that you get the position of the inverted wing struts and the ailerons right. The ailerons started inside of where the struts attach (i.e. closer to the wing root). Also pay attention to the wing struts, configured as a V, and wrongly depicted in some plans as the aft member being parallel to the TE, when in reality both struts converge at an angle (look at photos on the Net, easily found).

Bibliography: DeHavilland Aircraft since 1909 (A.J. Jackson)

N.A.C.A. Technical Memorandum No. 261

The Light Plane since 1909 - J. Underwood

The Light Plane Meeting at Lympne, Flight Magazine, Oct 18th 1923

The spar showing the changes in airfoil thickness:

Comparison between the D.H.53 and the Parnall Pixie, being built in parallel:

Control surfaces engraved, some of the interior parts:

Some reinforcement elements are added and a section of the deck prepared:

Details are added to the diverse parts. metal horns for all control surfaces, skid for the wingtips, holes for the rigging are drilled, etc.:

A general view of the parts so far:

The wing struts:

Decided to discard the seat from the spares bin and fabricate a wicker seat with a photoetched back. Once the interior is painted, the rest of the deck is going to be glued on: