The AISA I-115 is a low-wing single-engined military primary trainer with tandem seating, which went into service with the Spanish Air Force in 1956.

The I-115 inherited the tail wheel undercarriage of the production version of the I-11, the I-11B, but was a longer machine because the Spanish Air Force wanted tandem seating for its trainers, had a slightly greater span and was considerably heavier.

The tandem cockpits were enclosed with a long, glazed cover with independent sliding sections for both instructor and pupil.

They were initially known as the type EE.6, EE being Escuela Elemental or Primary Training, but when this category was dropped the I-115 became the E.9 (E for - Entrenamiento or Trainer).

Despite the long service, there was criticism of its spinning behaviour and its weight: apparently the unofficial nickname Garrapata or Tick was meant to describe the E.9's reluctance to leave its host, the ground.