Flown initially in standard US Army markings, in 1964 this aircraft was selected for world records attempts. David Hatcher states: "During record attempts it is common to strip aircraft of all unnecessary components and drag producers. Note the absence of windshield wipers, cargo door handle, stabilizer bar and dampners, covers of tail rotor driveshaft and 42° gearbox, cabin ventilation scoops, roof handhold, particle separator screen, and skid steps. Also note the 'taping' (for drag reducing) over the nose compartment door and latches, roof access steps and forward cargo door."
Not visible in this photo is the completely different and larger tail fin/rotor plylon. When the aircraft was converted for the record attempts the c/n was reapplied to the nose as was common practice during aircraft production. In 1964, flown by US Army pilots, this aircraft established twenty FAI World Records (all for turbine-powered helicopters without payload) on three locations: Edwards AFB, California (September), Fort Worth, Texas (October) and Hurst, Texas (November-December). According the FAI, seven of these records are still standing:
Sub-class: E-1d, T/O weight 3,858 to 6,614 lb (1,750 to 3,000 kg)
Speed, 311 mls (500 km) closed circuit: 178.23 mph (286.83 km/h)
Major Billy L. Odneal at Hurst, November 23
Speed, 621 mls (1,000 km) closed circuit: 146.08 mph (235.10 kmh)
Major John A. Johnston at Edwards, September 15
Altitude: 35,147 ft (10,713 m)
Major Eldon F. Sampson at Hurst, December 11
Sub-class: E-1e, T/O weight 6,614 to 9,921 lb (3,000 to 4,500 kg)
Speed, 311 mls (500 km) closed circuit: 172.13 mph (277.02 kmh)
Major Robert A. Chubboy at Hurst, November 23
Speed, 1,243 mls (2,000 km) closed circuit: 133.99 mph (215.63 kmh)
Chief Warrant Officer Joseph C. Watts at Edwards, September 23
Distance, closed circuit: 1,242.84 mls (2,000.15 km)
Chief Warrant Officer Joseph C. Watts at Edwards, September 23
Distance, in line: 1,348.81 mls (2,170.70 km)
Captain Michael N. Antoniou at Edwards, September 27
In 1966 this aircraft was converted to the sole YUH-1H with an upgraded engine.