Spain picks Airbus A321 for new signals intelligence aircraft

Spain has chosen the Airbus A321 as the foundation for its new signals intelligence (SIGINT) aircraft, marking a significant step in the Santiago II-SCAPA program. The decision was revealed in the October edition of the Spanish Air and Space Force's official publication, Revista de Aeronáutica y Astronáutica, though the Ministry of Defense has not yet made an official announcement. The program aims to restore Spain's dedicated airborne SIGINT capabilities, which have been absent since the retirement of the Boeing 707, known as Reina del Espectro, in 2014.

The Santiago II program will initially involve the acquisition of three A321 aircraft equipped to detect, locate, identify, and analyze electromagnetic emissions. Airbus and Indra are already collaborating on the project under a definition contract awarded in December 2025, with Airbus handling the aircraft platform and Indra focusing on sensors and mission systems. The 18-month study, valued at approximately €16 million (US$19 million), will lay the groundwork for the program's next phase.

The selection of the A321 provides Spain with a larger platform compared to business jets typically adapted for intelligence missions. The aircraft's spacious cabin, endurance, and payload capacity make it well-suited for long-duration intelligence-gathering operations. Additionally, the program requires that manufacturing and systems integration take place in Spain, ensuring national control over the integration of SIGINT equipment.

The Air and Space Force publication also hinted at the potential use of the A321 for a future airborne early warning aircraft, although no formal acquisition program has been launched. Airbus is already developing another military special-mission version of the A321 for France, the A321 MPA, which will replace the French Navy's Atlantique 2 maritime patrol aircraft.