• A modified Boeing 757-200 is being used as a testbed for the GCAP/Tempest sixth-generation fighter jet.
• The aircraft, named Excalibur, is part of a $146 million contract led by Leonardo UK.
• Excalibur will test technologies like electronic warfare and communications.
• The program aims to develop a next-generation integrated sensing and self-protection capability.

The use of a modified commercial aircraft as a testbed may indicate a cost-effective approach to developing complex fighter jet systems. This could suggest that the GCAP program is prioritizing efficiency and risk reduction, which may give it a competitive edge in the global market for sixth-generation fighter jets.