On August 13, 2025, the U.S. Air Force's specialized Boeing 737-200, designated NT-43A and known as RAT55, was observed conducting operations from the Groom Lake facility, commonly referred to as Area 51. Aviation enthusiast Michał Rokita captured footage of the aircraft performing touch-and-go maneuvers and a full stop landing on runway 32. Following its landing, the RAT55 taxied directly to Hangar 18, confirming its operational base and specific hangar.
The RAT55, also identified by its callsign "SABRE98," functions as a critical radar testbed. Its primary mission is to evaluate the radar signatures and stealth characteristics of advanced aircraft, including the B-2 Spirit bomber. This involves utilizing sophisticated radar technology and distinctive modifications, such as radomes fitted to its fuselage, to facilitate these assessments. The aircraft's capability to measure radar cross-sections (RCS) is essential for validating low-observable designs and ensuring stealth aircraft maintain their expected performance levels.
This recent sighting highlights the U.S. Air Force's ongoing commitment to advancing stealth technology, a key element of modern military aviation and national security. The RAT55's operations are integral to the development and testing of next-generation military platforms, such as the B-21 Raider and the anticipated F-47 fighter. Its presence at Area 51, a site renowned for aerospace innovation, underscores the facility's enduring importance in developing cutting-edge defense capabilities.
Historically, the RAT55 has been involved in similar activities. A notable sighting occurred in May 2025 when it was observed flying in formation with a B-2 Spirit bomber over Death Valley, California, further solidifying its role in assessing the radar detectability of stealth aircraft. The continuous testing and refinement of stealth technologies, including advanced radar-absorbent materials (RAM), are crucial for maintaining a strategic advantage in aerial warfare. The meticulous work conducted with assets like RAT55 ensures the U.S. maintains its technological edge in a complex global security environment.