As the "heavies" of the air which were pioneered by the American Air Forces come into their own over Europe, performance and construction details of the Handley Page Halifax four-engine bomber have been made available.
Affectionately called the Hallibag by pilots, it is a mid-wing cantilever monoplane, powered by four Rolls-Royce Merlin engines developing 1,175 bhp each at 20,500 ft, using three-bladed Rotol design constant-speed full-feathering propellers.
In construction the Halifax, like its predecessor the Hampden, is built on the split assembly principle to speed production, being divided into subassemblies to provide the widest possible labor spread.
The Halifax is all-metal covered, with flush-fitted skin seams and flush riveting. The fuselage is of monocoque construction with alloy hoop frames and longitudinal stiffeners, with the skin being attached to both hoops and stiffeners.
The wing is of two-spar construction, the spars combining both tubular and plate components, riveted to flanges of the extruded section. Ailerons are fabric covered aluminum sheet box construction. Trailing edge flaps are of Handley-Page design, extending from the fuselage to the ailerons. The exceptional area thus provided is said to give the Halifax a very short take-off even under heavy loads.
The stabilizer construction is similar to that of the wing, and carries twin rudders.
Flight, navigation and bomb control sections are grouped in compartments well forward of the engines and all carry full armor protection. Twin, bulbous nacelles in the extreme nose carry the front gunner and, below, the bombardier. Immediately aft of the bombardier is the navigator's compartment which, in turn, is below the pilot's cockpit. The flight engineer's "office" is just behind the cockpit and contains an astrodome of bullet-proof glass from which the control officer can direct operations against attack.
Over the wing center section in the fuselage is the crew's rest quarters, so located as to give easy access to the dinghy storage compartment located between the wing spars on the port side. Further aft on the upper side of the fuselage is the upper gun turret, which, like the others, is power operated. Also in this section is the flare launching station, giving access to a catwalk leading through to the tail gun turret.
Fuel tanks, carried in the wings, are self-sealing and with jettison pipes fitted to flexible connectors to the flaps. Both landing gear and flap operating mechanism are hydraulic, built under Messier patents.
Specifications and performance data on the Halifax are as follows:
|Wing area||1,250 sq ft|
|Fuselage width||5' 6"|
|Fuselage height||9' 6"|
|Max speed||300 mph (approx)|
|Max range||3,000 mi|
|Max bomb load||5½ tons|
|Gross wt||27 tons|
This article was originally printed in the August, 1942, issue of Aviation magazine, vol 41, no 8, pp 211, 269.
The original article includes a photo of a Halifax in flight and a labeled cutaway drawing.
Photo credited to Acme; drawing "Courtesy of Flight".