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Grigorovich I-Z

Soviet Union (1933)
Picture of Grigorovich I-Z Cannon-Armed Fighter Prototype

Limitations of the Grigorovich I-Z fighter design soon crept in to limited production of the type to fewer than 100 units.


Detailing the development and operational history of the Grigorovich I-Z Cannon-Armed Fighter Prototype.  Entry last updated on 4/3/2017. Authored by Staff Writer. Content ©www.MilitaryFactory.com

In the early 1930s, Dmitri Grigorovich, and the design bureau that bore his name, was charged with development of a new single-seat monoplane fighter for the Soviet Air Force. One of the chief qualities of its design would be mounting the new 76.2mm recoilless rifle developed by L.V. Kurchevski so the aircraft would have to be of considerable strength to manage the weapon. If successful, the fighter would become one of the most powerful of its type anywhere in the world - a danger to any bomber aircraft of the period.

Work began in mid-1930 and the program was given the designator of "Z" (Zet). Grigorovich had a working relationship with another aircraft-maker, Nikolai Polikarpov, and helped the Polikarpov design bureau bring the I-5 biplane fighter program to fruition. This exposure allowed Grigorovich to use the I-5's forward fuselage and engine fit to expedite development of his Z-fighter which came to be known as the "I-Z".

A low-wing monoplane form was used and the single pilot sat in an open-air cockpit above it. The fuselage tapered to the tail to which a single rudder was fitted along with high-mounted horizontal planes. The tail-dragger undercarriage was wheeled at only the two main legs, a skid being used under the tail unit. Power was from a French-originated Gnome-Rhone "Jupiter VI 9-cylinder radial piston engine (air-cooled) outputting 525 horsepower and driving a simple two-bladed propeller at the nose. Dimensions of the aircraft were a length of 25 feet and a wingspan of 37.8 feet. Empty weight became 2,600lb against an MTOW of 3,635lb.
Proposed armament - key to the success of the I-Z - was 2 x 76.2mm Kurchevski DRP recoiless rifles, one slung under each wing unit. The weapons were inherently single-shot by design so no ammunition supply was required to be built into the I-Z's wings or frame. Of note is the high positioning of the tailplanes and this was done to contend with the hot exhaust generated by these guns. Secondary armament was a single 7.62mm PV-1 machine gun in the fuselage, synchronized to fire through the spinning propeller blades. This weapon was to serve more as an aiming device than anti-aircraft measure.

Metal construction was used throughout the I-Z where possible, marking a shift in aircraft design philosophy which would soon see all-metal types appearing regularly. Fabric was used for skinning the machine and steel tubing strengthened various members.

The first I-Z prototype made it airborne in mid-1931 and a second prototype example appeared the following year as the "I-Zbis". In 1933, some 22 preproduction models followed and these differed in carrying the local Soviet version of the Gnome-Rhone engine, the "M-22" radial outputting 480 horsepower under a revised cowling assembly. Wooden wings were also used over the earlier model's metal forms.

In the air, the I-Z managed a maximum speed of 161 miles per hour and ranged out to 375 miles. The service ceiling for the aircraft reached 23,000 feet and time-to-altitude was 14 minutes to 5,000 meters.

50 I-Z production-quality fighters were ordered but the design was ultimately relegated to a life of testing and research for the aircraft exhibited poor spin recovery characteristics and the recoilless rifle pairing offered little benefit for the cost

Grigorovich then moved on another cannon-armed fighter - the "IP-1".






Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

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Relative Maximum Speed Rating
Hi: 200mph
Lo: 100mph
    This entry's maximum listed speed (162mph).

    Graph average of 150 miles-per-hour.
City-to-City Ranges
NYC
 
  LON
LON
 
  PAR
PAR
 
  BER
BER
 
  MOS
MOS
 
  TOK
TOK
 
  SYD
SYD
 
  LAX
LAX
 
  NYC
Graph showcases the Grigorovich I-Z's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
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Pie graph section
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Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
75
75


  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.


Altitude Visualization
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Origin: Soviet Union
Year: 1933
Type: Cannon-Armed Fighter Prototype
Manufacturer(s): Grigorovich OKB - Soviet Union
Production: 75
Global Operators:
Soviet Union (cancelled)
Historical Commitments / Honors:

Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
Measurements and Weights icon
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the Grigorovich I-Z model. Common measurements, and their respective conversions, are shown when possible.

Operational
CREW


Personnel
1


Dimension
LENGTH


Feet
25.10 ft


Meters
7.65 m


Dimension
WIDTH


Feet
37.73 ft


Meters
11.5 m


Weight
EMPTY


Pounds
2,601 lb


Kilograms
1,180 kg


Weight
LOADED


Pounds
3,638 lb


Kilograms
1,650 kg

Engine icon
Installed Power - Standard Day Performance:
1 x M-22 air-cooled radial piston engines developing 480 horsepower and driving a two-bladed propeller at the nose.

Performance
SPEED


Miles-per-Hour
162 mph


Kilometers-per-Hour
260 kph


Knots
140 kts


Performance
RANGE


Miles
373 mi


Kilometers
600 km


Nautical Miles
324 nm


Performance
CEILING


Feet
22,966 ft


Meters
7,000 m


Miles
4.35 mi


Performance
CLIMB RATE


Feet-per-Minute
1,170 ft/min


Meters-per-Minute
357 m/min

Supported Weapon Systems:

Graphical image of an aircraft medium machine gun
Armament - Hardpoints (0):

2 x 7.62mm Kurchevski DRP recoilless rifle (single-shot).
1 x 7.62mm PV-1 machine gun (for aiming).
Variants: Series Model Variants
• I-Z - Base Series Designation
• I-Zbis - Second prototype