Built as a replacement for the Loire 43, the Loire 45 employed a basically similar airframe, but fitted with an 800hp Gnome-Rhone 14Kds 14-cylinder radial air-cooled engine, three-bladed propeller, and strengthened wing bracing struts. Armament consisted of two 20 mm cannon Oerlikon, installed in wing compartments.
Flown for the first time on 20 February 1933, the prototype was transferred to Villacoublay in June for official testing. At the end of September 1933 formal trials began at the Aircraft Testing Center (SEMA). Military pilots found that the view from the cockpit, especially forward, unsatisfactory.
During the course of trials several modifications were made to the wing roots in attempts to improve visibility from the cockpit, an 880hp Gnome-Rhone 14Kcs was installed in August 1934, and, in the following October, the vertical tail surfaces were enlarged.
After the changes the aircraft returned to SEMA for comparative testing with other fighters Training dogfights showed that even with a new engine the Loire was heavy to fly and had poor maneuvering characteristics. Armament comprised two 20mm cannon in underwing gondolas, but visibility for the pilot was deemed unacceptable.
Once again suffering fighter was sent for revision and, after re-engining with a 900hp Gnome-Rhone 14Kfs with a wooden prop, the sole prototype was relegated to the role of parachute testing as the Loire 45 LP1. It flew in this form for the first time on 18 July 1935, but by that time the military has put an end to this project.
Max take-off weight: 1785 kg