Which designation indicates aircraft modified for reconnaissance missions?

The designation used for aircraft that have been modified specifically for reconnaissance missions is "Reconnaissance." These aircraft are equipped with advanced sensors, cameras, and other surveillance technology designed to gather intelligence and conduct observation missions over various terrain and enemy positions. Their primary purpose is to obtain vital information without engaging in direct combat, making them crucial for military strategy and situational awareness.

Trainer aircraft, on the other hand, are primarily designed for teaching and training purposes rather than for reconnaissance missions. Antisubmarine aircraft are specifically equipped to detect and deter submarines, focusing on maritime threats rather than aerial surveillance. VTOL/STOL refers to an aircraft's ability to take off and land vertically or on short runways, which does not inherently relate to reconnaissance capabilities, even though such aircraft could potentially be used for that purpose.