A vivid
portrait of Eng. Mario Castoldi, Macchi's designer, has been
drawn by his successor, Ermanno Bazzocchi: "Misogynous, good
wine loving, he had the hobby of rice growing. His huge and
heavy complexion was the most improbable for a man devoted
to catch for the speed. We believe he flew only once".
His irascible
character is reported in an exclamation "In FIAT, power is
measured in donkey-power", pronounced after the 1927 defeat.
Not casually, perhaps, before Venice race, Maria Vittoria De
Bernardi had been warned by Castoldi not to leave her
husband fly on such aircraft.
For Subofficer
Francesco Agello it0's sufficient to say that he reached the
record only when, after death of Lt. Ariosto Nari, he
remained the only pilot endorsed for MC-72. Heavy
responsibility on his shoulders must be paired with the
constant memory of the killed colleagues but also, we
believe, with the sense of revenge of a man damned to be an
eternal reserve.
About De
Bernardi, Baldassarre Catalanotto remembers when, talking
about his secret technique to turn around the pylon, he
answered: "When I first flew Macchi 39, it had no intention
to turn at all, to lower the wing. So, I kicked in the
pedals, ripped the stick and the aircraft turned very well.
Since then, I ever did so". Behind his simple words, one of
the best natural talents of pilot ever seen in Italy was
hidden, one in which technical ability was glued with
instinct to form an unbeatable champion.
Besides those
strong personalities, were peoples like Armand Palanca,
chief civil technician in RAV workshop and last to disappear
among Schneider's protagonists. After studying the problem
of turbulence around air intakes, Palanca studied and
patented a special carburettor, RAV.26, to solve the heavy
breathing failures of AS-6.
Macchi MC-72 after his record flight (107Kb)
The decision to
trust in a single type for 1931 edition mobilised resources
never available before, allowing to build sophisticated
devices to test the tricky FIAT AS-6 engine, conceived by
Eng. Tranquillo Serbi. To avoid the problems created by huge
propeller torque, Zerbi decided to adopt a double,
counter-rotating fixed-pitch propeller. Not only efficiency
was some 15% higher, but rear propeller was immediately
flooded by aur flow and was efficient even during take off.
In the
difficult floating phase, torque absence should allow to
have a balanced load on the floats: an important aspect,
considering that, with 1800HP engine, the left float was
loaded 23% more than right one. In 1931 Supermarine S-6B
with 2650HP was 32% overloaded, while MC-72 barely reached
3% even with 3000HP. Behind this propeller stand a singular
twin engine, obtained coupling on the same axle two 12V, 60
degrees engines directly derived from AS-5, each moving a
propeller through two coaxial crankshafts passing through
forward engine banks. Air intakes were in the centre,
between both engines, while breathing system, composed by a
centrifugal compressor and a bank of 8 aspirated
carburettors, was single for the whole plant.
The plates
"Front Engine" and "Back Engine", still in the cockpit, show
that semi-engines were independent, as confirmed by run-up
scene in the famous movie of the record. It seemed the
simplest solution, but, as often happens, AS-6 promises were
harder to win than expected.
Onde defined
the engine solution, airframe realization proceeded rapidly
and without problems. Design base was conditioned by the 4m
of the engine, and aircraft emerged as a steel tube frame,
acting both as engine mount and forward fuselage, completed
with mounts for wing, floats and rear fuselage. Wing
structure was also metal, with rectangular shape, covered
with flat surface radiators, while tail unit, with
empennages and cockpit, was a monocoque wooden structure.
Under the tail a further radiating element was foreseen.
The floats,
used as fuel tanks and also covered with flat radiators,
were initially metal but were eventually changed with
wooded, lighter and smaller ones. All above gave a very nice
and sleek aircraft, whose main section was lower than MC-67
one, giving no flight problems even if control surfaces were
not dynamically balanced as surprisingly happened in all
Schneider's planes.
What let the
participation to 1931 Schneider Cup to be abandoned was
finally AS-6 tuning, which emerged as difficult beyond any
prevision: 18 months tests first on loose parts, then on
subassemblies, finally on the whole engine, running for one
hour on April 20, 1931. It offered 2200HP only and burned
two valves.
problem
solution required two months, twelve different valves
combinations and 1000 valves in 10 different steels. Reached
at the end of May the 2400HP, an AS-6 was mounted on the
first MC-72: optimism of the tests were frozen on June 22th,
shortly after first take off. Detonations and flameouts, so
strong to crack the compressor, obliged Monti to land
immediately.
FIAT AS-6 engine, producing 2500/3000HP (103Kb)
While the test
flights continued, the necessary modifications were
implemented. Then on August 2nd, 1931, Monti crashed on take
off and died. Ltn Ariosto Neri and Stanislao Bellini took
over with the second MC-72: only 40 days were left before
the race, but no solution for the troubles was in sight.
On September
3rd, Ministres of Aeronautics of Italy and France asked
British Royal Aero Club to postpone the race one year: the
Britons refused, without fair play but pragmatically,
because their participation was only paid by sponsors, and
retiring that year could mean forever. Thus, on September
12th the British Supermarine flew alone. A record attempt
was held also in Desenzano, on September 10th, but concluded
dramatically: flameouts, detonations and MC-72 exploded in
flight. No escape for Bellini.
In two months,
RAV had been shocked and humiliated, but remained alive to
gain the world speed record and the 100Km one. To resolve
the carburration troubles a third engine test bed was set
up, filling a whole hangar where two 400- and 700HP engines
simulated wind up to 750Km/h. The device was used to verify
proper functioning of Palanca's RAV-26, fitted with
transparent elements to observe fuel flow.
On February 26,
1932, a 2400HP AS-6 simulated on the test bed a record
flight on 3Km basis: to get an ideal fuel "Rod" Banks, the
British wizard of fuel mixtures, was enrolled. He created a
mix of 55% gasoline, 22% benzol, 23% alcohol and 0,15% lead.
Engines were prepared with 3000HP for record runs and with
2500HP for endurance, working mainly on supercharging.
Neri and Agello,
eternal reserve, restarted flying in June: On 15th Neri had
the first flutter experience, landing safely only thanks to
his skill. Unfortunately, Neri died three months later on a
training flight on a CR-20.
Only Agello was
left, having scored an unofficial record of 664,078Km/h: a
third attempt was interrupted on June 4th after only 8
minutes. The final assault to 700Km/h was finally decided,
with Agello as pilot. After several aborts, a first attempt
was held on May 13th, interrupted for flameouts. Second
attempt on June 22th, aborted for compressor failure. Third
try on July 4th, with strong vibrations insurging. Then,
long stop until autumn.
Here's another
unsuccessful flight on October 1st. On October 13th, other
flameouts and further delay. On October 23rd, take off at
14,56: 64 seconds floating, light mist, then the four
official passes. Landing at 15,11, with Agello unaware to
have beaten his own record. After the calculations, average
resulted of 709,209Km/h, with the third, fastest pass at
711,462Km/h. Finally, decorations, promotions, celebrations
came, with the immediate storage in a museum of the three
MC-72 left, which perhaps never flew again.
In December
1938 RAV command was handed over to Agello, now Lieutenant,
which disbanded the remaining of the wing on May 6th, 1940:
61 men, including two officers and two pilots. Agello's
record resisted four years and a half, then was beaten two
times in a month: by Hans Dieterle on Heinkel 100V8 at
746,450Km/h on March 30th, 1939 and by Fritz Wendel on
Messerschmitt Me-209V1 at 755,1Km/h on April 26.
In seaplanes
category the record was overcome only on August 7th, 1961
when soviet jet plane Beriev M.10 of Nikolau Andrjewski flew
at 912Km/h.