Grumman OV-1 Mohawk

https://en.wikipedia.org/wiki/Grumman_OV-1_Mohawk

The Grumman OV-1 Mohawk was an armed military observation and attack aircraft,
designed for battlefield surveillance and light strike capabilities. It was a
twin turboprop configuration, and carried two crew members in side-by-side
seating. The Mohawk was intended to operate from short, unimproved runways in
support of United States Army maneuver forces.

Development

The Mohawk began as a joint Army-Marine program through the then-Navy Bureau of
Aeronautics (BuAer), for an observation/attack plane that would outperform the
Cessna L-19 Bird Dog. In June 1956, the Army issued Type Specification TS145,
which called for the development and procurement of a two-seat, twin turboprop
aircraft designed to operate from small, unimproved fields under all weather
conditions. It would be faster, with greater firepower, and heavier armour than
the Bird Dog, which had proved vulnerable during the Korean War. The Mohawk's
mission would include observation, artillery spotting, air control, emergency
resupply, naval target spotting, liaison, and radiological monitoring. The Navy
specified that the aircraft must be capable of operating from small "jeep"
escort class carriers (CVEs). The DoD selected Grumman Aircraft Corporation's
G-134 design as the winner of the competition in 1957. Marine requirements
contributed an unusual feature to the design. As originally proposed, the OF-1
could be fitted with water skis that would allow the aircraft to land at sea and
taxi to island beaches at 20 knots. Since the Marines were authorized to operate
fixed-wing aircraft in the close air support (CAS) role, the mockup also
featured underwing pylons for rockets, bombs, and other stores.

The Air Force did not like the armament capability of the Mohawk and tried to
get it removed. The Marines did not want the sophisticated sensors the Army
wanted, so when their Navy sponsors opted to buy a fleet oil tanker, they
dropped from the program. The Army continued with armed Mohawks and developed
cargo pods that could be dropped from underwing hard points to resupply troops
in emergencies.

The radar imaging capability of the Mohawk was to prove a significant advance in
both peace and war. The Side-Looking Airborne Radar (SLAR) could look through
foliage and map terrain, presenting the observer with a film image of the earth
below only minutes after the area was scanned. In military operations, the image
was split in two parts, one showing fixed terrain features, the other spotting
moving targets.

The very nature of the joint Army/Marine program had forced design compromises,
such as ejection seats, that made the aircraft expensive and, sometimes, an
openly resisted item in Army budgets. Orders for the OV-1 stopped in Fiscal
1964, and the controversy in the Pentagon over the armed Mohawk peaked with a
1965 directive that prohibited the Army from operating armed fixed-wing aircraft
(See the Johnson-McConnell agreement of 1966). Operational success in Vietnam
led to additional Mohawk orders in 1966, and by 1968, five surveillance
companies were operating in Southeast Asia.

The last of the Mohawk versions to enter production was the OV-1D with more
powerful T53-701 engines, improved avionics, and interchangeable mission pallets
that made it possible to switch the aircraft from infrared to SLAR configuration
in about an hour. The first four OV-1Ds were prototypes converted from earlier
production airframes, and the first flew in 1969. These were followed by 37
new-build aircraft, the last of which was delivered in December 1970.


Role
light attack and observation aircraft

Manufacturer
Grumman

First flight
14 April 1959

Introduction
October 1959

Retired
September 1996 (USA)

Status
Retired

Primary users
United States Army (historical)
Argentine Army Aviation (historical)

Produced
19
59–1970

Number built
380

Operational history

United States Army

The U.S. Army flew the OV-1 operationally in the Vietnam War, with sixty-five
lost to accidents, ground fire, and one shot down by a North Vietnamese fighter.
The Army also used the aircraft during Operation Desert Storm.

Starting in 1972, the Army National Guard (ARNG) began to receive the Mohawk,
with the ARNG eventually operating thirteen OV-1Bs, twenty-four OV-1Cs, and
sixteen OV-1Ds serving with three aviation units in Georgia and Oregon. The
Oregon Army National Guard Unit operating the Mohawk was located at McNary Field
in Oregon, initially as the 1042nd Military Intelligence Company (Aerial
Surveillance), then reflagged as the 641st Military Intelligence Battalion
(CEWI)(Aerial Exploitation).

U.S. Army OV-1s were retired from Europe in 1992, from Korea in September 1996,
and finally in the United States in 1996, superseded by newer systems, newer
aircraft, and the evolution of reconnaissance satellites. The OV-1 was primarily
replaced by the EO-5C, a militarized version of the de Havilland Canada Dash 7
turboprop airliner equipped with a SLAR system, until the U.S. Air Force's
Northrop Grumman E-8 Joint STARS (Joint Surveillance Target Attack Radar System)
aircraft became fully operational.

The Argentine Army Aviation received twenty-three OV-1 in the 1990s. Ten were
operational and the rest were used for spare parts. They became inactive and
retired from use in 2015.

Specifications (OV-1D)

General characteristics
Crew: 2
Length: 41 ft 0 in (12.50 m)
Wingspan: 48 ft 0 in (14.63 m)
Height: 12 ft 8 in (3.86 m)
Wing area: 360 sq ft (33 m2)
Aspect ratio: 5.35:1
Airfoil: NACA 2412
Empty weight: 12,054 lb (5,468 kg)
Gross weight: 15,544 lb (7,051 kg) (Normal take-off weight, IR mission)
Max takeoff weight: 18,109 lb (8,214 kg) (SLAR mission)
Fuel capacity: 276 US gal (230 imp gal; 1,040 L) internal fuel
Powerplant: 2 × Lycoming T53-L-701 turboprops, 1,400 shp (1,000 kW) each
Propellers: 3-bladed Hamilton Standard Type 53C51-27 constant-speed propellers,
10 ft 0 in (3.05 m) diameter

Performance
Maximum speed: 305 mph (491 km/h, 265 kn) (IR mission)
Cruise speed: 207 mph (333 km/h, 180 kn) (econ. cruise)
Stall speed: 84 mph (135 km/h, 73 kn)
Never exceed speed: 450 mph (720 km/h, 390 kn)
Range: 944 mi (1,519 km, 820 nmi) with external tanks (SLAR mission)
Endurance: 4.35 hr (SLAR mission)
Service ceiling: 25,000 ft (7,600 m)
Rate of climb: 3,466 ft/min (17.61 m/s) (SLAR mission)
Take-off to 50 ft (15 m): 1,175 ft (358 m)
Landing run from 50 ft (15 m): 1,060 ft (320 m)




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