Aviation News — February 2018

(Darren Dugan) #1
a military wing licence. As a result, it trained
mainly pilots destined for the fighter fleets (F-
104, G.91 and, from the early 1980s, Tornado)
and the activity went on for many years with
no real changes. In September 1975, the 205°
Gruppo was disbanded.
A reorganisation of the flying schools
resulted in July 1986 with the SVBAA being
re-designated 60a Brigata Aerea. On July 1,
1993, in sight of the retirement of the G.91T/1
fleet, the 60a Brigata Aerea was disbanded
and its squadrons were re-assigned to the
32° Stormo, which was moved from Brindisi to
Amendola. The 13° Gruppo left the G.91Y and
started to fly with the G.91T/1, waiting for the
delivery on the new AMX.
The G.91T/1 soldiered on for about two
more years and on September 15, 1995 the
204° Gruppo, the last squadron flying the type,
was deactivated.
The final flight of the T model was recorded
on September 30. Last to fly was aircraft
MM.6363 (code ‘32-63’), painted in a striking
special livery. This was the last G.91 to fly in
the world.
Gen Fausto Bernardini (ret’d), who
recorded 3,600 hours and nearly 20 years
on the G.91, including 1,800 as instructor
pilot on the G.91T/1, said: “The G.91, single
and two-seater, carried a poor warload to be
considered a real warplane, but on the other
hand, the T was an unmatchable trainer in
all the types of flight, including the air-to-air
missions, using the machine-guns against
towed targets.
“[Just] think that Iraqi cadets, who trained
in Italy with us, could convert to the MiG-
21 with just half [the number] of the sorties
scheduled for the others [cadets]. Old
instructors were used to saying that the G.91T
was unstable, handy (but this doesn’t mean
easy), with whom it was better to be not too
confident. It had critical areas of buffeting and
g-stall, especially in the vertical manoeuvres,
under 300kts. Surprisingly, these problems
disappeared below 220kts and until 150kts,
when the T docilely followed its pilot.”

G.91Y
In the mid-1960s, Fiat decided to develop a
new lightweight fighter-bomber, destined to
replace the G.91R in the Italian Air Force,
and possibly to raise the interest of other air
arms. In addition, the AM needed the aircraft
to be capable of medium-range interdiction
missions as a successor to the last F-84F.
Industry and the air force combined to develop
a new project, which still had to be robust,
simple, agile and subsonic, but able to provide
improvements over the G.91R/1 in terms of
endurance, armament, navigation systems
and survival capability.
Fiat decided to start from the G.91T
airframe, but introduced remarkable
modifications. In effect, the aircraft was a
completely new machine, but Fiat decided to
call it G.91Y, probably to exploit – especially
on the export market – the good reputation
gained by the R model.
The new design’s biggest change was the

adoption of a twin-engine formula, and a new
wing, which was derived from the aborted
G.91A project.
The G.91T fuselage, bigger and able to
accommodate two engines and more fuel, was
modified and received a new nose, a new and
larger air intake, a more streamlined cockpit
and a much larger tail section, which also had
two ventral fins and two small air intakes, to
cool the afterburner sections.
The layout of the main systems and
equipment was similar to that of the R model.
Fixed armament was improved – not fitted to
removable panels – and comprised two DEFA
552 30mm guns, each with 125 rounds.
The one engine air intake was designed
to feed two engines, and its single channel
split inside the fuselage into a Y-shaped
configuration (from which the designation of
the type was derived).
This solution, selected to maintain the
previous aerodynamic layout, would later
become a source of problems. The wing was
quite different, with a sweep of 37°40’, slotted
flaps and automatic slats on the leading
edge. It also had four pylons, each able to
carry up to 1,000lb (454kg) of stores. The
landing gear was stronger than in the R type,
and had bigger wheels, to bear the increased
weight and maintain the capability to fly from
unpaved runways.
To shorten the landing run, a brake chute
was installed in the tail, while in case of need,
the take-off could be assisted by thrust from
small rockets, called a JATO system which
would have been installed as and when
required. The arresting tail hook could be used

not only in an emergency, but also to land on
short runways.
A big improvement was the adoption of
two turbojets with afterburner, the General
Electric J85-GE-13A, each delivering 4,075lb
(1,850kg) in full reheat. The G.91Y was the
only variant to have afterburners.
The fuel system was formed of six tanks
in the fuselage, plus two in the wings, for a
total of 3,200 lit. In addition, the inner wing
pylons were ‘wet’, accepting 260, 520 or 800 lit
external fuel tanks.
The armament, besides the two guns, was
Mk.82 and Mk.83 free-fall or retarded bombs,
BL.755 cluster bombs, Orione, LAU-3A and
LAU-18 rocket pods, for a total of 4,000lb
(1,816kg).
The nose held four cameras: a Fairchild
KA-60C 180° forward-looking panoramic, two
lateral and one vertical De Oude Delft TA-7M2.
A wide range of instruments in the cockpit
included for the Bendix DRA-12 Doppler
radar, a Ferranti ISIS-B fire control system,
a Honeywell AN/APN-171 radar altimeter, a
Specto gun sight, a Marconi AD-370 ADF,
UHF radios and SIF/ATC TRA-62 IFF.
The first prototype (NC.2001, MM.579) flew
for the first time on December 22, 1966 from
Turin Caselle, piloted by Vittorio Sanseverino.
From the start, the Y type showed excellent
flight qualities, power and agility. During
testing, it proved to be a stable firing platform,
but began to show problems with engine stalls
at high altitude (around 40,000ft/12,120m),
a problem which, due to the single air intake
duct, provoked a nearly simultaneous flame
out in the two engines.

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A 14° Gruppo (white band on fin) G.91R taxies at Treviso in May 1985. Riccardo Niccoli

Fiat G.91R MM.6398 from 103° Gruppo (yellow band on fin) at Treviso in May 1985. Riccardo Niccoli

48-54_fiatDC.mfDC.mfDC.mf.indd 53 08/01/2018 16:40

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