Conceptually, the Grumman OV-1 Mohawk was designed as a multipurpose aircraft; however, the brief combat experience of the experimental JOV-1A version demonstrated that the Mohawk had much more potential as a surveillance and reconnaissance plane.
One of its prototypes was equipped with Side Looking Airborne Radar (SLAR) fitted in an 18-foot long box-shaped pod mounted under the front fuselage and offset to the right. Just like the OV- 1A, the OV-1B also carried optical cameras.
The new type was named the OV-1B and it differed considerably from the OV-1A. Wingspan was stretched by 1.97 meters (5 feet 10 inches) to improve climb rate, and the armament pylons and airbrakes were deleted to reduce weight. Along with all these changes, the previous dual control cockpit was superseded by a new crew arrangement of pilot and SLAR operator.
The innovative SLAR designed and produced by Motorola provided reconnaissance imaging capability in day or night in any weather and could work automatically. The SLAR also had a Moving Target Indicator capability to highlight moving vehicles in imaging using an APN-129 Doppler system.
101 OV-1B were produced and they operated all over Vietnam. Some units were equipped with both the OV-1A and the OV-1B. They were intensively used in 1965 in Operation Tiger Claw, providing surveillance and air support along the Ho Chi Min Trail. They were also used with the B-52 strategic bomber and the AH-1 Cobra helicopter as a pathfinder. The enemy is said to have referred to the OV-1B as the 'Whispering Death' because of its extremely quiet turboprop engines. The OV-1B won a reputation of invulnerability so any Vietcong soldier who brought one down was recommended for a high decoration.
The Mohawk was also used by civil organizations. SLAR sensors proved particularly useful in geological and geodesic missions. The US Geological Survey bought a few Grumman OV-1B Mohawks and in 1971 performed low altitude geological and hydrological research, and mapping missions over the Alaskan Highlands to study Arctic glaciers and carry out surveys of the Alaskan oil pipeline.
A few Mohawks made guest star appearances in TV series such as 'Airwolf' and 'Blue Thunder'. Others (not only the OV-1B) ended up in private hands. These enthusiasts organise annual meets of their unofficial fan club in the USA
- Grumman OV-1B Mohawk, (N171) of the U.S. Department of the Interior, Geological Survey 1971.
- Grumman OV-1B Mohawk, s/n 59-2673, 131st Surveillance Airplane Company, Phu Bai, Vietnam 1967.
- Grumman OV-1B Mohawk, s/n 64-14270, 73rd Surveillance Airplane Company, Vung Tau, Vietnam 1967.