66 The Aircraft of British Aerospace and BAE SYSTEMS 1977 - 2017
W
hen British Aerospace
came into being in 1977
the 38 Nimrod MR1s and
three R1s were already
bedded down in service with the RAF.
The MR1s had replaced the ancient
Shackletons in the RAF Maritime
Reconnaissance role and the R1s
though outwardly similar were
especially developed versions for
electronic reconnaissance and took
over from three Comet 2Rs. Whereas
the Nimrod MR1s, MR2s and the R1s all
put in years of invaluable service, the
two succeeding marks though
developed and costing billions, never
entered service but were ignomini-
ously and controversially scrapped.
The Nimrod design was based on a
Comet 4 airframe with the wing centre
section enlarged to take four Rolls-Royce
Spey 250s instead of Avons. An
unpressurised pannier fitted under the
pressurised fuselage provided a 48ft
long weapons and equipment bay and a
large nose radome, to allow for existing
and future radar scanners. The largeweapons bay could carry of a variety of
weapons; bombs, torpedoes and depth
charges - alternatively house air-sea
rescue gear, or long-range fuel tanks for
global ferrying, or freight panniers.
Owing to the increased side area, a
prominent dorsal fin was fitted and an
Electronic Counter Measures fairing at
the top of the fin. To make the aircraft
even more distinctive there was a
Magnetic Anomaly Detector mounted in
a long tail boom.
The pilots’ windscreens were
deepened to confer better visibility
during search, and two eyebrow windows
added to enable the crew to look into the
turn when the aircraft was banked during
manoeuvres at low altitude. In addition,
two underwing pylons were introduced
for external stores and a trainable 70
million candlepower searchlight was
installed in the front of starboard external
wing tank.
The Rolls-Royce Spey 250 was rated at
11,500lb and thrust reversers were fitted
on the outboard tailpipes. The Nimrod
could climb quickly to a transit altitude of30,000ft and cruise at 400kt, descending
to search altitude and shutting-down the
outboard engines as required. For
low-level searches, two engines were kept
running at a fairly high thrust level to
retain a low specific consumption. The
aircraft could climb on one engine at
normal search weights and on two
engines at maximum weight. The crew
numbered 11 consisting of two pilots,
one flight engineer, two lookouts, a
routine navigator, a tactical navigator, a
radio operator, an ASV radar operator and
two sonar operators.Flight test
As there were two Comet 4Cs remaining
unsold on the Broughton production
these were reworked as Nimrod
prototypes. The first Nimrod prototype
XV148 flew on 23 May 1967 from
Broughton to Woodford and the second,
XV147 from Woodford on 31 July 1967.
XV148 was rebuilt with Spey engines,
however as it would have been a more
costly task to rebuild XV147 with Speys it
retained its Rolls-Royce Avons. The final Comet
on the production
line was rebuilt as
the first Nimrod
prototype at
Broughton and
made its first flight
to Woodford on 23
May 1967. Note the
large number of
cabin windows
which differentiated
it from the
production
Nimrods. The MAD
tail boom is not
fitted in this photo
as an anti-spin
parachute was
installed in its place.
(Avro Heritage)Nimrod - from success
to cancellation