It was designed in response to a requirement released by the Armée de l'Air (French Air Force) for a new twin-seat observation aircraft.

This design, which was of a large all-metal sesquiplane, made extensive use of high-tensile steel for all stressed elements of the structure, a choice that represented a considerable departure from accepted practice of the era; the Bréguet 27 would be the first aircraft to employ such construction.

[4] One key advantage of this structural approach was to permit the size of the fuselage to be minimised considerably which, amongst other benefits, impinged less upon the range of both vision and fire of the observer, although visibility for the pilot remained broadly similar to that of conventional aircraft.

[5] Despite its unorthodox nature, evaluation of the design proved that the Bréguet 270's aerodynamic efficiency was equal to that of most conventional aircraft of the era.

[3] Seeking to ease the tasks of maintenance, repairs, and replacement, the assembly of the aircraft was deliberately shaped so to maximise interchangeability and standardise elements such pins and bolts.

[8] It featured flanges made from large drawn plates with reinforcing corrugations joined by sheet webs stiffened in a similar manner.

This undercarriage, which was directly mounted onto the lower wing's single spar, comprised two completely independent wheels without any kind of leg or strut.

[10] Instead, a relatively sturdy bracket, akin to the head lug of a motorcycle, that received the upper end of the fork supporting the wheel was used.

The bracket incorporated a oleo-pneumatic shock absorber, the design of which Bréguet secured a patent on, as well as a special type of wheel bearing.

[11] The relatively large track of the undercarriage made contract between the ground and a wing tip reasonably implausible while air resistance was also reduced to a minimum.

[17] The pilot's cockpit was relatively roomy and comfortable; all instrumentation was conveniently placed while a curved windshield protected the occupant from external weather conditions.

The observer's cockpit, which was also provided with a windshield, had a camera mounting installed in front of it, which, in combination with sliding apertures in the bodywork, facilitated convenient photography from both vertical and oblique orientations.

All three air intakes were mounted along the same horizontal line; short exhaust stacks were typically provided, although some aircraft had silencers fitted for night operations.

[21] Breguet 27s continued in military service through the outbreak of World War II, still equipping three Groupes at the time of the initial German offensive.