Here are the three fastest planes in the world as of my last knowledge update in September 2023

Certainly! Here's a brief description of the three fastest planes in the world as of my last knowledge update in September 2021:

1. Lockheed Martin SR-71 Blackbird:
- The SR-71 Blackbird is an iconic reconnaissance aircraft known for its incredible speed and sleek design.
- It was capable of reaching speeds exceeding Mach 3 (around 2,200 miles per hour), making it the fastest manned aircraft ever built.
- Designed for high-speed, high-altitude reconnaissance missions, it served the United States Air Force from 1966 to 1998.

2. North American X-15:
- The X-15 was an experimental rocket-powered aircraft that pushed the boundaries of flight during the 1960s.
- It reached remarkable speeds, with its fastest recorded flight reaching Mach 6.72, or approximately 4,520 miles per hour.
- The X-15 contributed valuable data for future space and aircraft development and set numerous speed and altitude records.

3. NASA X-43:
- The X-43 is an unmanned experimental aircraft designed for hypersonic research.
- It set a world record for the fastest speed ever achieved by an aircraft, reaching Mach 9.6 (about 7,347 miles per hour) during a flight in 2004.
- The X-43 program aimed to advance our understanding of hypersonic flight and its potential applications.

Keep in mind that these descriptions are based on information available up to September 2021, and developments in aviation technology may have occurred since then.