The Aviation Historian — January 2018

34 THE AVIATION HISTORIAN Issue No 22

were not described in detail since they were the
subject of intensive study at the Royal Aircraft
Establishment (RAE) at Farnborough, the Royal
Radar Establishment at Malvern and various
firms within the electronics industry. But the
overriding problem was how to deliver a
conventional bomb to within 200yd (600ft/180m),
or a nuclear bomb within 400yd (1,200ft/360m),
of a target at a range of 1,000 miles (1,800km) in
any part of the world under visual conditions
and from low altitude. It was assumed that any
target may be heavily defended by radar, SAGWs
and automatically-controlled anti-aircraft fire and
that the only attack that offered a reasonable hope
of survival against these hazards would be made
at very low level and the highest practical speed.
Studies showed that as speed increased beyond
Mach 0·9 at decreasing altitudes below 500ft
(150m) then the chances of survival increased
rapidly. However, an aircraft designed to be
strong enough for a prolonged supersonic dash
at sea level became increasingly large and the
approach speed to the target was consequently
pegged by the drag rise. Over rolling country,
however, contour flying within this height
bracket further reduced the attacking aircraft’s
vulnerability. The prospective flightplan around

which the navigation system had to be designed

therefore envisaged a medium-altitude subsonic

cruise to within about 200 miles (370km) of the

target, followed by a rapid let-down and cruise

at Mach 0·9–0·95 at 500ft above ground level

(agl). There could be no question of a search in

the defended area so a direct approach must be

made terminating in a loft-attack and a reciprocal

return path. The navigation system must also be

compatible with a maximum speed at medium

altitude in excess of Mach 2, and it should be

secure against electronic countermeasures (ECM).

For the P.1129 the loft-bombing, or LABS (Low

Altitude Bombing System) technique, also known

as “over-the-shoulder” bombing, would consist

of a low-level run-in towards the target, a 4–5g

pull-up, during which the weapon was released,

and then a roll off the top to return. The object of

this method was to place the aircraft as far from

the explosion as possible, and also to avoid the

need to fly into the centre of what was probably

going to be a highly defended area. Even so, the

height attained during the manœuvre would

make the aircraft vulnerable to groundfire.

The avionics included a development of the

AI.23 AIRPASS set with an 18in (46cm) dish as

The colour scheme on this speculative artwork of the original P.1129 design with semicircular
intakes, comprising uppersurface camouflage in Dark Sea Grey and Dark Green, with Anti-Flash
White on the undersurfaces and low-visibility fuselage roundel is based on BAC Drawing 57900 White on the undersurfaces and low-visibility fuselage roundel is based on BAC Drawing 57900
of November 1964 for a proposed scheme for the first pre-production batch of TSR.2s.
Artwork by JUANITA FRANZI / AERO ILLUSTRATIONS © 2018

Although Hawker was unable to give a great deal of Although Hawker was unable to give a great deal of
information in its January 1958 brochure about the information in its January 1958 brochure about the
various electronics, radio and radar systems proposed various electronics, radio and radar systems proposed
for the P.1129, for obvious security reasons, the for the P.1129, for obvious security reasons, the
brochure does provide this schematic detailing their brochure does provide this schematic detailing their
locations within the airframe. The brochure goes into locations within the airframe. The brochure goes into
some detail regardng the navigation systems and some detail regardng the navigation systems and
equipment, but is understandably tight-lipped on the equipment, but is understandably tight-lipped on the
radar and fire-control systems.radar and fire-control systems.

Radar equipmentRadar equipment

Electronic equipmentElectronic equipment

Radio equipmentRadio equipment The brochure does state, however,
that the forward-looking radar would
contribute to the navigation of the aircraft
to some degree, and so provides a few details of
the nose-mounted radar equipment. It revealed that
this would be a development of Blue Parrot, itself
an upgraded version of the AI.23 AIRPASS system
devised for low-level operations and target detection,
TAH ARCHIVE and later fitted to the Blackburn Buccaneer.

Click here to see original 1958 P.1129 schematic diagram