The Bell 533 was referred to as the High Performance Helicopter (HPH) by the Army, and reached a top speed of 274.6 knots (508.6 km/h; 316.0 mph) in 1969, before being retired.

The U.S. Army began a program to study improvements to current helicopters that could be demonstrated by testing.

[2] The reconfigured helicopter was first tested in the NASA Ames Research Center wind tunnel, which confirmed that the modifications had significantly reduced the aircraft's drag.

The 533 made its maiden flight on 10 August 1962 at Bell's Fort Worth, Texas headquarters[3] utilizing the two-bladed UH-1B rotor.

[2] Starting on 21 October 1963, Bell began test flights with two Continental CAE J69-T-9 turbojet engines in nacelles mounted directly to the aft portion of the fuselage.

Bell immediately fitted the two-bladed rotor with tapered blade tip caps for the company's own independent testing.

The blade tip modification allowed the helicopter to reach 193 knots (222 mph; 357 km/h) using the maximum auxiliary thrust from the Continental turbojets.

[2][4] The final configuration of the Model 533 for the research contract was with a proprietary, four-bladed, flex-beam rigid rotor developed by Bell.

[2] The Model 533 is on display (in highest speed configuration) at the US Army Aviation Applied Technology Directorate, Fort Eustis, Virginia.