Dyle et Bacalan DB-10

https://en.wikipedia.org/wiki/Dyle_et_Bacalan_DB-10

The Dyle et Bacalan DB-10 was a heavy night bomber, designed in France and flown
in 1926. It was a twin engine, high wing, metal frame monoplane, distinguished
by a very thick centre section wing which formed the forward fuselage and housed
the engines.

In 1925 the well-established naval ship builders Société Anonyme de Travaux Dyle
et Bacalan, based in Bordeaux, developed an aircraft manufacturing interest.
Their first production was a high wing, twin engine heavy bomber, the DB-10.
Like their later aircraft, the DB-10 was structurally an all-metal machine. In
most respects the DB-10 was a conventional design for its day but it had one
feature, a very thick wing centre section blended into the fuselage, which was
also to become a characteristic of later Dyle et Bacalan aircraft.

At the front of the DB-10 the thick aerofoil centre section stretched unbroken
between the engines, which were mounted upon it. Beyond the engines outer wings
of normal thickness and constant chord, significantly thinner and narrower than
the inboard section, were each supported by a pair of parallel struts to the
lower edge of the centre section. Wing spars and struts were made of steel
tubing, with duralumin ribs. A conventional, rectangular section, fuselage with
duralumin longerons emerged from the centre section as the thick aerofoil
thinned, carrying a tailplane on its upper surface, braced from below. It also
carried a single fin and a deep rudder, which moved in a cut-out between the
elevators. All surfaces, except those housing the uncowled Gnome-built Bristol
Jupiter radial engines, were fabric. The DB-10 had a fixed, conventional
undercarriage with each single, partly cowled, mainwheel mounted on a parallel
pair of V-shaped struts behind the engines. The outer pair of struts was fixed
close to the lower ends of the wing struts, at the edge of the thick aerofoil. A
tailwheel was mounted at the rear of the fuselage, just in front of the rudder.

The thick centre section enclosed vertical bomb racks as well as fuel tanks.
Open cockpits for the crew were built on top of it, starting with a
navigator/bombardier's or gunner's position at the extreme leading edge.
Immediately behind but stepped above it was the pilot's cockpit, with another
cockpit just aft where the raised crew housing ended. There was a separate
dorsal gunner's position, fitted with a gun ring, on the fuselage proper.


Role
Heavy night bomber

National origin
France

Manufacturer
Dyle et Bacalan, Bordeaux

First flight
1926

Number built
1

The DB-10 was entered into the 1926 French government BN3 competition for a new
three man night bomber, held at Villacoublay where it flew against such aircraft
as the Amiot 122, the Farman F.123, the Latécoère 19 and the eventual winner the
Lioré et Olivier LéO 20. Only one DB-10 was built, though the company persisted
with the thick wing idea in its later DB-70 transport aircraft.

Specifications

General characteristics
Crew: 3/4
Length: 13.60 m (44 ft 7 in)
Wingspan: 25 m (82 ft 0 in)
Height: 3.80 m (12 ft 6 in)
Wing area: 93.0 m2 (1,001 sq ft)
Empty weight: 3,150 kg (6,945 lb)
Gross weight: 5,600 kg (12,346 lb)
Powerplant: 2 × Gnome et Rhône 9A Jupiter 9-cylinder radial, 360 kW (480 hp)
each
Propellers: 2-bladed fixed pitch wooden propellers

Performance
Maximum speed: 195 km/h (121 mph; 105 kn) at sea level

173 km/h (107 mph; 93 kn) at 4,000 m (13,000 ft)Service ceiling: 5,500 m (18,000
ft)
Wing loading: 60.1 kg/m2 (12.3 lb/sq ft)
Power/mass: 0.1126 kW/kg (0.0685 hp/lb)

Armament

Guns: 2× 7.7 mm (0.303 in) Lewis guns in nose gunner's position
Bombs: 1,300 kg (2,900 lb) bombs in internal bomb bay