Bréguet 270

{{Infobox aircraft |name= 270 |image= Breguet 274.jpg |caption= Breguet 274 with Gnome-Rhône 14K (Mistral Major) 900 HP engine |type= Reconnaissance aircraft |manufacturer= Breguet |designer= Marcel Vuillierme, Rene Dorand |first_flight= 23 February 1929 |introduction= 1930 |retired= 1939 |status= |primary_user= ''Armée de l'Air'' |more_users= Venezuelan Air Force and China |produced= |number_built= over 227 |variants= }}

The '''Bréguet 270''' was a sesquiplane military reconnaissance aircraft designed and produced by the French aircraft manufacturer Breguet.

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 clean-sheet aircraft featured unusual fuselage that ended abruptly, aft of the two open cockpits, while the empennage was mounted on a boom behind the fuselage. It performed its maiden flight on 23 February 1929. In addition to its adoption by the ''Armée de l'Air'', it was also sold on the export market to both Venezuela and China.

==Design and development== The Bréguet 27 was designed in response to a 1928 request for proposals issued by the ''Armée de l'Air'' that sought a new two-seat observation aircraft to replace the Bréguet 19.<ref name"av603p7">{{harvnb|Cortet & Moulin ''Avions'' June 2002|p=7}}</ref> Bréguet decided to produce a new aircraft to submit for this requirement. 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.<ref name = "naca 13">NACA 1930, pp. 1-3.</ref>

The first prototype, powered by a {{convert|500|hp|kW}} Hispano-Suiza 12Hb engine, made its first flight on 23 February 1929.{{sfn|Cortet & Moulin ''Avions'' August 2002|pp=18–19}} The first prototype underwent a number of changes during testing, including the fitting of rectangular tail surfaces, a revised rear fuselage and a metal propeller.{{sfn|Cortet & Moulin ''Avions'' August 2002|p=19}} It was followed by nine more prototypes, some of which were fitted with a {{convert|500|hp|kW}} Renault 12Jc engine.{{sfn|Cortet & Moulin ''Avions'' August 2002|pp=21–23}} The design was optimised to allow operation out of small airfields, with a takeoff run of only {{convert|115|m|ft|abbr=on}} when fully loaded, although maximum speed suffered as a result of this focus on short field performance.{{sfn|Cortet & Moulin ''Avions'' September 2002|p=34}} In 1920, the Breguet 270 was selected as winner of the competition for an observation aircraft, ahead of the Potez 39 and the ANF Les Mureaux 131.{{sfn|Cortet & Moulin ''Avions'' September 2002|p=34}} In December 1931, an initial order was placed for 50 Breguet 270 A2, followed by an order for 35 more in 1932 and finally another order for 55 aircraft, giving a total of 140.{{sfn|Cortet & Moulin ''Avions'' September 2002|p=34}} The second placed Potez 39 was also ordered into production.{{sfn|Passingham|1996|pp=42–43}} Two high-altitude reconnaissance versions were also built as the '''Breguet 33''', but these did not lead to further production.

==Design== The Bréguet 270 was a twin-seat sesquiplane military reconnaissance aircraft that featured a somewhat unorthodox design. Its structure was entirely rigid, lacking any internal or external bracing wires or rods and thus excluding rigging.<ref name = "naca 2"/> All stressed structural members were composed of high-tensile steel, while secondary members, such as coverings, cowlings, and formers were typically composed of light alloys instead. Light alloys had been intentionally avoided for primary structures due to its mechanical properties.<ref name = "naca 1,2">NACA 1930, pp. 1-2.</ref> 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.<ref name = "naca 14">NACA 1930, pp. 1-4.</ref> 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.<ref name = "naca 4">NACA 1930, p. 4.</ref>

The various parts of the aircraft were typically assembled using riveting, which studies has determined to be the preferential method; exceptions were occasionally made in order to make disassembly of the overall aircraft practical, thus in such circumstances bolts were used instead.<ref name = "naca 2"/> Neither studs or welding were used in the construction process. All parts were designed to facilitate automatic riveting by machine while the number of rivets was reduced to a minimum via the use of processes such as the corrugating of sheet metal and the rolling of edges in order that riveted stiffeners could be dispensed with.<ref name = "naca 2"/> 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. Permanent jigs were used for all subassemblies.<ref name = "naca 2">NACA 1930, p. 2.</ref>

Being a sesquiplane, the lower wing of the Bréguet 270 was considerably smaller than the upper wing, accounting for only 17.6 per cent of the total area.<ref name = "naca 3">NACA 1930, p. 3.</ref> Despite this, the lower wing was the centre point of the aircraft's structure, and thus had immense strength. Being a single-piece unit, it comprised a single spar of box construction composed of steel.<ref name = "naca 34"/> It featured flanges made from large drawn plates with reinforcing corrugations joined by sheet webs stiffened in a similar manner. Internal frames of stamped steel provided considerable strength while the ribs, composed of sheet steel, featured rolled-edge lightening holes, slid on the spar and secured by riveted steel fittings.<ref name = "naca 4"/> The wing covering was composed of duralumin sheeting that ran lengthwise between two adjacent ribs and riveted along the edges of the latter through an interposed inverted U-shaped strips of duralumin. Attachments for steel fittings at each end of the spar were provided for the wing struts.<ref name = "naca 4"/>

In addition to its primary aerodynamic purpose, the lower wing served various secondary purposes. Its internal space accommodated, amongst other things, a total of four fuel tanks; for greater fuel capacity, the leading edge on either side could be replaced by a tank that had an identical external shape.<ref name = "naca 5">NACA 1930, p. 5.</ref> The lower wing also bared a 'backbone' that substitutes for a conventional fuselage as well as the undercarriage. 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.<ref name = "naca 25">NACA 1930, pp. 2-5.</ref> 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.<ref name = "naca 910">NACA 1930, pp. 9-10.</ref> 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.<ref name = "naca 10">NACA 1930, p. 10.</ref>

The structure of the upper wing comprised two identical I-shaped steel spars with corrugated sheet steel webs and butterfly drawn profiles as flanges.<ref name = "naca 5"/> It was free of compression tubes, except where struts joined with the spars. The upper wing was supported via struts attached to the tips of the lower wings in addition to the central cabane.<ref name = "naca 35">NACA 1930, pp. 3, 5.</ref> The bracing members comprised two channel steel profiles that were riveted together back to back and disposed at right angles. It was strengthened using ribs, the majority of which were composed of duralumin while a minority of master ribs were composed of steel instead.<ref name = "naca 5"/> A third false spar, composed of duralumin, was used to anchor the ailerons. These ailerons were divided into two portions, one of which was elastically mounted in such a manner that the effort required by the pilot was relatively uniform.<ref name = "naca 235">NACA 1930, pp. 2-3, 5.</ref> Actuation of the ailerons was achieved via a series of toothed rods. As a result of the unusual strut arrangement used, the upper wing's incidence could be adjusted relatively easily via the use of a special spanner.<ref name = "naca 67">NACA 1930, pp. 6-7.</ref>

The aircraft's backbone is composed of two distinct parts, a central box and the tail boom; the former consisted of a steel beam of a small cross-section, attached at its forward end to the central box and resting directly on the lower wing, to which is bolted to the detachable engine unit.<ref name = "naca 37">NACA 1930, pp. 3-7.</ref> The cockpits formed an independent unit that was superimposed upon the central box to form, together with the engine cowling, the bodywork of the aircraft. Various different types of bodies, furnished with appropriate equipment for the mission to which the aircraft was to be tasked, with were available.<ref name = "naca 34">NACA 1930, pp. 3-4.</ref> The demountable body housing the pilot and observer's cockpits was of light duralumin construction; access to both cockpits was acquired via doors that were mounted so that they could be rapidly dropped mid-flight by merely knocking a lever so that emergency egress via parachute was as easy as possible for both crew.<ref name = "naca 12">NACA 1930, p. 12.</ref> 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.<ref name = "naca 12"/>

The forward end of the tail boom was attached to the rear of the central box by means of a heavy triangular stamped steel frame and a U-shaped steel frame.<ref name = "naca 8">NACA 1930, p. 8.</ref> The rear end of the tail boom supported the stabilizing surfaces of the tail unit along with a compact swivelling wheel for the undercarriage. The design of the tail boom was particularly convenient in respect to the flight controls, all connections with the tail's movable surfaces were concealed inside of the spar while a conventional rudder bar was dispensed with in favour of a pair of pivoting pedals, one on each side of the spar.<ref name = "naca 8"/> All connections with the tail surfaces and ailerons were rigid; dual control were fitted as standard although the observer's stick was removable. The use of tubes was intentionally avoided wherever possible.<ref name = "naca 89">NACA 1930, pp. 8-9.</ref>

The Bréguet 270 was designed to be powered by virtually any engine in the 500 to 650 hp range; it uses a relatively simple steel engine mounting that gave good accessibility to all parts that required attention.<ref name = "naca 10"/> It could be replaced in mere minutes, being secured to the forward portion of the central box by only four pins. The cowling was provided with horizontal hinges, akin to a car's bonnet, and acted as both an oil tank and cooler.<ref name = "naca 1011">NACA 1930, pp. 10-11.</ref> Directly beneath the engine was a radiator; cooling was regulated using shutters fitted in the cowling. 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.<ref name = "naca 11">NACA 1930, p. 11.</ref>

==Operational history== In December 1932, the Breguet 270 entered service with a squadron tasked with evaluating the new type, with the Breguet entering regular service in May 1933.{{sfn|Cortet & Moulin ''Avions'' September 2002|p=36}}{{sfn|Danel|Cuny|1980|pp=81, 83}} Through 1934, the Breguet 270 and Potez 39 gradually replaced the Breguet 19s in the reconnaissance squadrons in Metropolitan France.{{sfn|Danel|Cuny|1980|p=83}} The type was temporarily grounded twice in 1935, between February and April, due to inflight tail boom failures, and from June to August after problems with excessive vibrations.{{sfn|Cortet & Moulin ''Avions'' September 2002|pp=39, 42}} In 1937, as the ''Armée de l'Air'' began to re-equip its front line units, single-engine observation aircraft like the Breguet 270 and Potez 39 were transferred to newly established ''Groupes Aériens Régionaux'' (GARs) (Regional Air Groups), with a core of experienced aircrew supplemented by reservists and using observer officers from the Army.{{sfn|Cortet & Moulin ''Avions'' September 2002|p=42}}{{sfn|Passingham|1996|pp=44–45}} Breguet 27s equipped 12 GARs in January 1938.{{sfn|Cortet & Moulin ''Avions'' September 2002|p=44}} In August 1938, during the Munich Crisis, General Joseph Vuillemin, Chief of Staff of the French Air Force, gave orders that, in the event of war breaking out, the obsolescent equipment of the GARs should never cross the front line.{{sfn|Passingham|1996|p=45}} 27s continued in military service through the outbreak of World War II, still equipping three ''Groupes'' at the time of the initial German offensive. After they began suffering combat losses, the Army withdrew all remaining examples from service. thumb|Codos and Robida, 1932 The two Breguet 33 high-altitude reconnaissance prototypes were used to make significant long-distance flights. The first aircraft was flown from Paris to Hanoi in January 1932 by Paul Codos and Henri Robida in 7 days, 9 hours and 50 minutes, and back again in just 3 days 4 hours and 17 minutes. The second aircraft (christened ''Joé III'') was flown by Maryse Hilsz on a tour of Asia, visiting Calcutta, Saigon, Hanoi, and Tokyo before returning to Paris via Saigon, eventually covering around 35,000 km (22,000 mi). Hilsz also won the 1936 Coupe Héléne Boucher flying a Breguet 27 at an average speed of 277 km/h (172 mph).

The French army ordered 85 270s in 1930. In 1932, 45 '''Breguet 271'''s, with a more powerful 484 kW (650 hp) engine, and larger useful load were ordered. Older 270s were modified for VIP liaison duties.

==Variants== ;Breguet 27S :A single Bre.27S was constructed, modified from the Bre.330 No.2, powered by a single Hispano-Suiza 12Nb engine.

;Bre.270 :Prototypes (ten built) and initial production version (143 built) powered by a single Hispano-Suiza 12Hb engine.<ref name="EWA">{{cite book| editor = Donald, David | title=The Encyclopedia of World Aircraft | volume = | pages = 118 | publisher = Prospero Books | date = 1997 | isbn = 1-85605-375-X | accessdate = }}</ref>

;Bre.271 :Version powered by the Hispano-Suiza 12Y engine, 45 built.

;Bre.272 :Version powered by the Gnome-Rhône 9Kdrs engine, two built.

;Bre.272TOE :(''Théatres des Operations Extérieures'') Version optimised for harsh colonial conditions with Renault 9Fas radial engine, 1 built.

;Bre.273 :Reconnaissance-bomber variant for export, powered by a Hispano-Suiza 12Ybrs engine, 13 built and one converted from a Bre 270. Ten more were built for China powered by Hispano-Suiza 12Ydrs engines, with three also being modified from Hispano-Suiza 12Ybrs powered versions.

;Bre.274 :Version powered by a {{convert|825|hp|kW|abbr=on}} Gnome-Rhône 14Kdrs radial engine. One built and first flown in January 1934. Raced by Maryse Hilsz in 1935.{{sfn|Cony, Cortet & Moulin ''Avions'' November 2002|p=47}}

;Bre.330 :High-altitude version of Breguet 27 with Hispano-Suiza 12Nb engine, one later redesignated '''Bre.27S''', two built.

;;Bre.330.01 :Second Bre.330 prototype optimised for long-duration flight.

==Operators== ;{{BRA}} * Brazilian Air Force received small batch of Bre.270 aircraft. ;{{China as ROC}} * Chinese Nationalist Air Force received ten Bre.273 aircraft in 1934.{{sfn|Cony, Cortet & Moulin ''Avions'' November 2002|p=45}} ;{{flagcountry|French Third Republic}} * ''Armée de l'Air'' received 85 Bre.270 designated '''Bre.270A.2''' and 45 Bre.271 designated '''Bre.271A.2'''. ;{{Flag|Vichy France}} * Vichy French Air Force got ahold of remaining Bréguet 270's when France collapse in 1940. ;{{flag|Venezuela|1930}} * Venezuelan Air Force operated three Bre.270 aircraft and nine Bre.273 aircraft.{{sfn|Cony, Cortet & Moulin ''Avions'' November 2002|pp=41, 43}}

==Specifications (Bre.270A.2)== thumb|Breguet 270 3-view drawing from NACA Aircraft Circular No.127 {{Aircraft specs |prime units? = met |ref=<ref name="av903p34-6">{{harvnb|Cortet & Moulin ''Avions'' September 2002|pp=34–36}}</ref> |crew= two (pilot and observer) |length m= 9.76 |upper span m= 17.01 |lower span m= 7.58 |height m= 3.58 |wing area sqm= 49.67

|empty weight kg= 1,676 |gross weight kg= 2,550 |max takeoff weight kg= 2,900 |eng1 number= 1 |eng1 name= Hispano-Suiza 12Hb |eng1 type= water-cooled V12 engine |eng1 kw= |eng1 hp= 500 |prop blade number= 2 |prop name= Bréguet |prop dia m= 3.05 |fuel capacity= {{convert|490|L|USgal impgal|abbr=on}} (maximum) |max speed kmh= 236 |max speed mph= |range km= 1,000 |range miles= |ceiling m= 7,750 |ceiling note= (absolute ceiling) |time to altitude=<br/> ** Six minutes and 10 seconds to {{convert|2000|m|ft|abbr=on}} ** 29 minutes to {{convert|6000|m|ft|abbr=on}} |guns=<br/> **1 × fixed, forward-firing 7.7 mm (.303 in) Vickers machine gun **1 × trainable, rearward-firing 7.7 mm (.303 in) Lewis Guns for observer |bombs= 12 × {{convert|10|kg|lb|abbr=on}} bombs }}

==See also== {{aircontent |related= |similar aircraft= |lists= * List of Interwar military aircraft |see also= }}

==References== {{Commons category}} ===Citations=== {{Reflist}} ===Bibliography=== * {{cite magazine |last1=Cony |first1=Christophe |last2=Cortet |first2=Pierre |last3=Moulin |first3=Jacques |title=Premier des "tout acier", le Bréguet 270 et sa descendance: 4 / De la "drôle du guerre" à la campagne de France |magazine=Avions |language=French |date=October 2002 |issue=115 |pages=20–33 |ref={{harvid|Cony, Cortet & Moulin ''Avions'' October 2002}} }} * {{cite magazine |last1=Cony |first1=Christophe |last2=Cortet |first2=Pierre |last3=Moulin |first3=Jacques |title=Les Bréguet 27 à l'étranger |magazine=Avions |language=French |date=November 2002 |issue=116 |pages=41–51 |ref={{harvid|Cony, Cortet & Moulin ''Avions'' November 2002}} }} * {{cite magazine |last1=Cortet |first1=Pierre |last2=Moulin |first2=Jacques |title=Premier des "tout acier", le Bréguet 270 et sa descendance |magazine=Avions |language=French |date=June 2002 |issue=111 |pages=7–14 |ref={{harvid|Cortet & Moulin ''Avions'' June 2002}} }} * {{cite magazine |last1=Cortet |first1=Pierre |last2=Moulin |first2=Jacques |title=Premier des "tout acier", le Bréguet 270 et sa descendance |magazine=Avions |language=French |date=August 2002 |issue=113 |pages=18–27 |ref={{harvid|Cortet & Moulin ''Avions'' August 2002}} }} * {{cite magazine |last1=Cortet |first1=Pierre |last2=Moulin |first2=Jacques |title=Premier des "tout acier", le Bréguet 270 et sa descendance: 3 / L'entre-deux-guerres |magazine=Avions |language=French |date=September 2002 |issue=114 |pages=34–47 |ref={{harvid|Cortet & Moulin ''Avions'' September 2002}} }} * {{cite magazine |last1=Cortet |first1=Pierre |last2=Moulin |first2=Jacques |title=Breguet 330 : Les derniers "tout acier" |magazine=Avions |language=French |date=December 2002 |issue=117 |pages=47–51 |ref={{harvid|Cortet & Moulin ''Avions'' December 2002}} }} * {{cite book |last1=Danel |first1=Raymond |last2=Cuny |first2=Jean |title=L'Aviation Française de Bombardement et de Renseignement (1918/1940) |year=1980 |location=Paris |publisher=Editions Larive |series=Docavia |volume=12 |language=fr |oclc=465337806}} * {{cite magazine |last1 = Passingham |first1 = Malcolm |title = Overtaken by Events: The Potez 39 Family |magazine = Air Enthusiast |location = Stamford, UK |publisher = Key Publishing |issue = 64 |date = July–August 1996 |pages = 42–47 |issn = 0143-5450}} * {{cite book |last= Taylor |first= Michael J. H. |title=Jane's Encyclopedia of Aviation |year=1989 |publisher=Studio Editions |location=London |pages=199 }} * {{cite book |title=World Aircraft Information Files |publisher=Bright Star Publishing |location=London |pages=File 890 Sheet 81 }} * [https://ntrs.nasa.gov/citations/19930090418 "The Breguet 270 General-Purpose Military Airplane (French) : A Two-Seat All-Steel Sesquiplane"] ''National Advisory Committee for Aeronautics'', 1 September 1930. NACA-AC-127, 93R19708.

==External links== *[Aviafrance.com Breguet]

Category:1920s French military reconnaissance aircraft Category:Single-engined tractor aircraft Category:Sesquiplanes Category:French patrol aircraft 0270 Category:Aircraft first flown in 1929 Category:Aircraft with fixed conventional landing gear Category:Single-engined piston aircraft