CANT Z.511

infobox Aircraft
name = CANT Z.511
type = Seaplane
manufacturer = Cantieri Riuniti dell'Adriatico


caption =
designer = Filippo Zappata
first flight = October 1940
introduction =
retired =
status =
primary user =
more users =
produced =
number built = 2
unit cost =
developed from =
variants with their own articles = The CANT Z.511 was a four-engined long-range seaplane designed by Filippo Zappata of the "Cantieri Riuniti dell'Adriatico" (CRDA) company. Originally designed for the Central and South Atlantic passenger routes, it was later adapted as a military transport and special raider.

Design and development

The design for the construction of a large four-engined, twin-float seaplane began at the end of September 1937, when the technical department of CRDA accepted the specifications of the LATI (Compagnia Ala Littoria) company, created in 1939, who required a long-range seaplane for carrying mail, cargo and passengers to Latin America.

These plans were cancelled on the outbreak of World War II, but a version of the aircraft was adapted for long-range maritime reconnaissance and sea patrols, and armed with 10 single-mount 12.7 mm machine guns in both sides, in two upper turrets, and belly positions. Plans were made to install 20 mm cannon in a front turret or in a glazed nose position, and more machine guns in a tail position.

For bombing it was adapted to carry up to 4,000 kg of bombs in an internal bomb bay and on outer wing positions; with four launch racks for 450 mm air-launched torpedoes, or to carry "Maiale" manned torpedoes or midget submarines for special operations.

The original engines were relatively underpowered, so Zappata asked the authorities for permission to acquire some American 1,600 hp Wright Double Cyclone R-2600s, but was unable to obtain authorization due to the deteriorating international situation. The CANT Z.511 civil aircraft could theoretically carry 16 passengers over 5,000 km (3,084 miles). Later when adapted as a military transport four 1,500 hp Piaggio P.XII RC 35 were used giving only adequate power to an aircraft weighing up to 34 tonnes, giving it a maximum range of 2,796 miles.

Flight tests

The Z.511 had its first test flights at Monfalcone, Venezia Giulia (north-eastern Italy) between October 1940 and March 1942. Between 28 February and 1 March 1942 test pilot Mario Stoppani succeeded in taking off and landing fully loaded in very rough seas, with 1.5 metre waves and winds of 55-65 km/h. The Z.511 prototype was then transported to Grado, Venezia (further away from the insecure Yugoslavian border) for further evaluations; the last test and operational flight occurred on 1 September 1943 the same day that the Italian Armistice was signed.

After the division of the Italian forces, one aircraft was appropriated by the Fascist Aeronautica Nazionale Repubblicana. However, it had been damaged only three weeks before by British fighters, which had strafed it on Lake Trasimeno where it was undergoing final trials. It was transferred to the seaplane base at Vigna di Valle. There it suffered from sabotage by base personnel to prevent it falling into the hands of either the Allies or the Germans. The other aircraft, still under construction at the CRDA factory, was retained by Axis forces and scrapped for the metal, which was sent to Germany.

Planned operations

In early 1942 plans for a number of different long-range special missions were made. The unique and unusual ideas were proposed by the Aviazione Ausiliara per la Marina (Naval Aviation Service) as well as strategists of the Regia Aeronautica.

Several projects were considered:
* An operation to liberate 55 captured Italian soldiers and pilots held in Jeddah, Saudi Arabia, by Arab-British forces; such a plan was indeed carried out for Italian Navy Airborne Forces.Fact|date=April 2007

* An air-raid on the strategic Soviet ports of Batumi and Poti in the Black Sea, or a raid against the port of Baku in the Caspian Sea.

* An attack on British oil installations at Bahrain on the Persian Gulf.

* A non-stop Rome-Buenos Aires flight (of 8,000 km) to evacuate prominent political and military Fascist personalities if needed.

* A special propaganda mission, taking off from Bordeaux, France, refuelling from German Kriegsmarine "Milch Kuhn" ("milk cow") U-boat tanker submarines, to fly over New York City, dropping one ton of propaganda leaflets.
* A raid against the Port of New York, with two aircraft each carrying four "Siluro a Lenta Corsa" human torpedoes (nicknamed "Maiale") to attack port facilities and ships. The crews were 16 special naval volunteers, who after completing their mission would be permitted to surrender, since there was no provision for them to return to the seaplanes. By May 1943 Kriegsmarine U-boat support had been obtained, the CANTs had successfully tested launching the "Maiale", and the volunteers had been chosen and trained for the one-way operation. The raid was scheduled for mid-June. However the aircraft was damaged by British fighters when the CANT's base in Lake Trasimeno was strafed. The arrest of Mussolini in July 1943 and the subsequent signing of the Italian Armistice by Marshal Pietro Badoglio (the new Italian leader) meant that the New York raid, and all other plans, were cancelled.

pecifications (Z.511)

aircraft specifications
plane or copter?= plane
jet or prop?= prop
ref=
crew= Six
capacity=Sixteen passengers (civil)
length main= 28.50m
length alt= 93 ft 6 in
span main= 39.86m
span alt= 130 ft 9 in
height main= 11.0m
height alt= 36 ft 1 in
area main= 195.0 m²
area alt= 2,098 ft²
airfoil=
empty weight main= 20,692 kg
empty weight alt= 45,522 lb
loaded weight main= 34,200 kg
loaded weight alt= 75,240 lb
useful load main= 2,000 kg
useful load alt= 4,400 lb
max takeoff weight main=
max takeoff weight alt=
more general=
engine (prop)= Piaggio P.XII RC 35
type of prop= radial engines
number of props=4
power main= 1,120 kW
power alt= 1,500 hp
power original=

max speed main= 424 Km/h at 4,000 m
max speed alt= 228 knots, 262 mph
cruise speed main= 330 km/h
cruise speed alt= 177 knots, 203 mph
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 4,532 km
range alt= 2,447 nm, 2,796 mi
ceiling main= 7,550 m
ceiling alt= 24,764 ft
climb rate main= 4.16 m/s
climb rate alt= 820 ft/min
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
* 10 × Breda-SAFAT or Cannone-Mitragliera da 20/77 (Scotti) 12.7mm machine guns in both sides, two upper turrets, and belly positions.
* Up to 4,000 kg bombload in internal bomb bay and mounted on outer wing positions
* 4 × launch racks for 4 × 450 mm Aerial Torpedoes or "Maiale" manned torpedoes.
avionics=

ee also

aircontent
see also=
related=
similar aircraft=
sequence=
lists=
*List of aircraft of Italy, World War II
*List of seaplanes and flying boats

References

* [http://www.vvsregiaavions.com/RegiaHTML/rz5111.htm Cantieri Z-511 IdroGigante images]
* [http://www.comandosupremo.com/Cantz511.html comandosupremo.com]
* John & Elke Weale, "Combat Aircraft of World War Two" (pp.193-205), Arms and Armour Press, London, 1978.
* "World War Two Magazine", Article : "Germany, Italy and Japan each had plans to strike the U.S. mainland, but the plans were delayed...too long" by Frank Joseph (pp.10-20) Published by Empire Press Inc., March 1993.
* Spanish Military Review "Serga", (Historia Militar del Siglo XX), Article "CANT, la oficina aeronautica de la Cantieri Navale Triestino", by Carlo D'Agostino (translated into Spanish by D. Garcia) (pp.42-48), Almena Ediciones, N 10, March-April 2001.