The pilot was provided with an ejection seat and the aircraft was intended to be fitted with six 20-millimeter (0.8 in) MG 151 autocannon in the nose and to be able to carry 1,000 kilograms (2,200 lb) of ordnance under the wings.

Test pilot Jacques Guignard attempted to make the first flight on 13 January 1949, but he was unable to take off despite achieving a speed of 200 kilometers per hour (124 mph).

The design team resorted to cutting V-shapes into the booms to give it an angle of 2°15' which would allow the aircraft to be trimmed nose-upwards to facilitate a takeoff.

Further high-speed taxiing trials were made in February with promising results, but the elevator had to be enlarged from an area of 1.75 to 2.6 m2 (18.8 to 28.0 sq ft), extending it past the vertical stabilizers, before it could make its maiden flight on 1 April.

The test pilots noted that the Narval tended to go into a dive when engine power was reduced, something that would make carrier landings very difficult, and that it demonstrated poor flying characteristics whenever the flap were retracted or extended.

During a flight on the second prototype on 16 December, Carpentier confirmed most of the official observations, commenting that he found it impossible to perform an aileron roll at a speed of 460 km/h (290 mph).