Mosquito Design Facilitates Production

by James Montagnes, Aviation's Canadian Correspondent

With plywood fuselage constructed in lengthwise halves, control and wiring installations are simplified. De Havilland Aircraft of Canada uses Packard-built engines in producing these formidable craft.

In designing the now-famed Mosquito bomber, de Havilland engineers considered ease of production as well as aerodynamic efficiency, as is evidenced by the rate of production by de Havilland aircraft of Canada alone.

First step in creating the plane is construction of the fuselage in lengthwise halves, which are built up of plywood sheets laid over a concrete form. Shaping of the sheets is achieved by bending them into place on the form and holding them by means of tacks driven into wood strips set into the concrete. Using a special plastic bonding agent, the fuselage is built up to proper thickness, the bonding agent being dried by a battery of 250 infrared lamps. One of the largest such batteries in Canada, the infrared unit was designed especially for Mosquito production.

Other structural sections of the fuselage, such as the five main bulkheads, are built up from smaller pieces of wood, which are cut, bent, and bonded on molds before being bonded as an integral part of the fuselage of the Mosquito.

This work is done in one plant, the halves then being shipped to the company's main plant outside Toronto. Here the two halves are set up in fixtures and all possible wiring and control installations made. This system eliminates the necessity of employees working in cramped space, thus speeding production considerably. When the two halves of the fuselage have been fitted and bonded into one unit, the whole is fabric covered.

Moved then to the final assembly area, it receives the empennage and plywood wing, the latter with landing gear already attached.

The aircraft is then placed in jigs which keep it in flying position as it moves through the final assembly area where engines, nacelles, bomb racks and doors, instruments, self sealing fuel tanks, and other units, are installed.

The plastic cockpit cover is put in place after the armor-backed pilot's and bombardier-radio operator-navigator's seats have been installed. The transparent plastic nose is put in place after the bombardier's instruments are all in and all controls for operating bomb racks and bomb doors have been tested.

Access to the plane is through a small hatch via a collapsible metal ladder. The bombardier's seat is to the pilot's right so that the bombardier can drop down and lie full length over the hatch opening with the upper part of his body in the nose of the plane where the bomb sight is located.

When the Mosquito was first put in production in Canada, some of the instruments were made in England. Now, however, these are being replaced with Canadian and American built units, some of which have required considerable modification in the original cockpit layout and wiring.

Canadian-built Mosquitos are powered by Packard-built Rolls-Royce Merlin 21 engines developing 1,250 hp.

Releasable specifications include the following:

Span54 ft 2 in
Length40 ft 9 in
Height15 ft 3 in
High speed (approx) 400 mph
Range (maximum)2,000 mi
Armament (reported)four 20-mm cannon and
four 0.303 machine guns
Power2 Packard Rolls-Royce Merlin 21s

This article was originally printed in the May, 1943, issue of Aviation magazine, vol 42, no 5, pp 259, 261.
The original article includes 7 photos of the Mosquito assembly line.
Photos are not credited.