View source for Northrop Delta

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{|{{Infobox aircraft begin
  |name = Delta<!--please avoid stating manufacturer in this field; it's stated two lines below -->
  |image = Northrop Delta 1.jpg
  |caption = <!--image caption; if it isn't descriptive it should be left blank-->
}}{{Infobox aircraft type
  |type = Transport aircraft
  |manufacturer = [[Northrop Corporation]]
  |designer = [[John Knudsen Northrop|Jack Northrop]]
  |first flight = May 1933
  |introduced = 1933<!--date the aircraft entered or will enter military or revenue service-->
  |introduction= <!--date the aircraft will enter military or revenue service, if the aircraft is still in development -->
  |retired = <!--date the aircraft left military or revenue service. If vague or multiples, it probably should be skipped-->
  |status = <!--in most cases, this field is redundant; use it sparingly-->
  |primary user = [[Royal Canadian Air Force]]<!--please list only one, and don't use those tiny flags as they limit horizontal space-->
  |more users = <!--limited to three "more users" total. please separate with <br/>-->
  |produced = <!--years in production, e.g. 1970-1999, if still in active use but no longer built-->
  |number built =32 
  |unit cost = 
  |developed from = [[Northrop Gamma]]<!-- the aircraft which formed the basis for the topic type -->
  |variants with their own articles = <!-- variants OF the topic type -->
}}
|}
The '''Northrop Delta''' was an [[United States of America|American]] single-engined passenger transport aircraft of the 1930s.  Closely related to Northrop's [[Northrop Gamma|Gamma]] [[mail plane]], 13 were produced by the Northrop Corporation, followed by 19 aircraft built under license by [[Canadian Vickers Limited]].

==Development and design==
When [[John Knudsen Northrop|Jack Northrop]] set up the Northrop Corporation as a joint venture with the [[Douglas Aircraft Company]] in 1932, he set out to design two closely related single-engined aircraft as the new company's first products: a mailplane/record-breaking aircraft, which was designated the [[Northrop Gamma|Gamma]], and a passenger transport, the '''Delta'''.<ref name="Francillon p23-4,143">Francillon 1979, pp.23–24, 143.</ref>  The Delta was a low-winged [[monoplane]], with a fixed [[Conventional landing gear|tailwheel undercarriage]]. It was of all-metal, stressed-skin construction, with streamlining spats covering the main landing gear.  While the Delta's wings were common with those of the Gamma, it had a new, wider fuselage, which seated the pilot in an enclosed cockpit immediately behind the engine, and had accommodation for eight passengers in a cabin behind the pilot.<ref name="Green v7 p57">Green 1967, p.57.</ref><ref name="Francillon p157">Francillon 1979, p.157.</ref>

The first Delta was flown in May 1933, and received an airworthiness certificate in August that year.<ref name="Francillon p157"/>

==Operational history==
Although it was intended that the Delta would be sold in both airliner and executive transport (initially named "Victoria") versions,<ref name="Latest Northrops p123">[https://www.flightglobal.com/pdfarchive/view/1934/1934%20-%200123.html?search=Latest%20Northrops ''Flight'' 8 February 1934, p.123].</ref> a change to the regulations governing commercial air transport in the United States in October 1934, prohibiting the use of single-engined aircraft to carry passengers at night or over rough terrain which would prevent a forced landing, stopped the market for single-engined airliners in the United States, and only three aircraft, all ordered before the passing of this regulation, were built as airliners.<ref name="Francillon p157"/> These consisted of the prototype, leased to [[Trans World Airlines]] for use to carry [[airmail]], which crashed on 10 November 1933, one sold to [[Pan American World Airways|Pan-Am]] for use by its [[Mexico|Mexican]] subsidiary, destroyed by a fire in May 1934 and one sold to [[AB Aerotransport]] of [[Sweden]], delivered in April 1934. AB Aerotransport purchased a second Delta, but this was a dedicated mailplane which more closely resembled the Gamma, with a slim fuselage carrying its cargo in a compartment ahead of the cockpit.

A single aircraft was built for the [[United States Coast Guard]].  Designated the '''Northrop RT-1''', this was used as the personal transport of [[Henry Morgenthau Jr.]], the [[United States Secretary of the Treasury|Secretary of the Treasury]] and as a staff transport.<ref name="Francillon p163">Francillon 1979, p.163.</ref>  Seven more aircraft were built as executive transports for private owners.  Of these, three were purchased by the [[Second Spanish Republic|Spanish Republicans]] for use in the [[Spanish Civil War]]. Two of these aircraft were captured by the Nationalists when the ship carrying them (along with four [[Vultee V-1]]s, a [[Fairchild 91]] and a [[Lockheed Model 10 Electra|Lockheed Electra]]) was captured at sea.  These two Deltas were used as Transports by Franco's forces, while the third Delta was used by the Republican airline [[Lineas Aéreas Postales Españolas]] (LAPE) until the end of the civil war when it was handed over to Franco's air force.<ref name="Francillon p159-61">Francillon 1979, pp.159–161.</ref>

In 1935, Canada selected the Delta for use as a photographic survey aircraft for use by the [[Royal Canadian Air Force]] (RCAF), to be built by [[Canadian Vickers Limited|Canadian Vickers]] under license.<ref name="Green v7 p57"/> One aircraft, the last Delta built by Northrop, was supplied as a part assembled pattern to Canadian Vickers, first flying on 16 August 1936 and being delivered to the RCAF on 1 September that year.<ref name="Green v7 p58">Green 1967, p.58.</ref>  It was followed by a further 19 aircraft built wholly by Canadian Vickers, production continuing until October 1940.<ref name="Green v7 p60">Green 1967, p.60.</ref> The Northrop Delta was the first completely all-metal, stressed-skin aircraft built in Canada, however it was closely preceded by the [[Fairchild Super 71]], whose stressed skin construction was limited to the fuselage and not the flying surfaces.

The Deltas, which were capable of being operated from wheeled, ski or float undercarriages, proved capable survey aircraft, well suited to operations in the north of Canada, but in August 1939, when the outbreak of the [[Second World War]] loomed, Canada found itself short of coastal patrol aircraft, and the Deltas were diverted to this role, being fitted with floats and carrying out long anti-submarine missions. The Deltas were less successful as patrol floatplanes, as they were damaged by ocean swell and by salt water corrosion, and they were forced to revert to landplane use after two months.  The Delta was withdrawn from operations in late 1941, then being used as instructional airframes in training schools.<ref name="Green v7 p60">Green 1967, p.60.</ref>

==Variants==
[[File:Aerovias Centrales Northrop Delta 1B X-ABED.jpg|thumb|Northrop Delta 1B in Mexican service with [[Aerovias Centrales]]]]
[[File:Richfield Oil Company - The Richfield Eagle - Northrop Delta 1D NC13777 (cropped).jpg|thumb|Northrop Delta 1D flown by the [[Richfield Oil Company]]]]
[[File:RCAF Canadian Vickers-built Northrop Delta Mk.I (cropped).jpg|thumb|RCAF Canadian Vickers-built Northrop Delta Mk.I]]
;Delta 1A
:Prototype. Powered by {{cvt|710|hp}} [[Wright R-1820|Wright SR-1820-F3 Cyclone]] radial engine. One built.<ref name="Francillon p157"/>
;Delta 1B
:Passenger airliner for Pan-Am.  Powered by {{cvt|660|hp}} [[Pratt & Whitney Hornet]]. One built.<ref name="Francillon p158">Francillon 1979, p.158.</ref>
;Delta 1C
:Passenger airliner for AN Aerotransport. Powered by {{cvt|700|hp}} Hornet.<ref name="Francillon p158"/>
;Delta 1D
:Executive aircraft, powered by Cyclone or Hornet engines. Eight built, including one '''Northrop RT-1''', powered by {{cvt|735|hp}} Cyclone for United States Coast Guard.
;Delta 1E
:Airmail carrier for AB Aerotransport. One built. Powered by {{cvt|660|hp}} Hornet.<ref name="Francillon p159">Francillon 1979, p.159.</ref>
;Delta I
:Survey aircraft for RCAF. Powered by {{cvt|775|hp}} SR-1820-F52 Cyclone. Three built, including pattern aircraft and two license built. Based on the 1D-8.
;Delta IA
:Partial modification to Mk.II standards, with bomb racks fitted.
;Delta II
:Revised version with provision for armament, including bombs, a dorsal turret mounting a .30 in [[M1919 Browning machine gun|Browning machine gun]] (later removed) and two wing mounted machine guns.  Nine built.<ref name="Green v7 p59">Green 1967, p.593</ref>
;Delta III
:Unofficial designation for Mk.II fitted with enlarged tail surfaces to counter tail buffeting from turret. Eight built.<ref name="Green v7 p59"/>
;RT-1
:United States Coast Guard designation for its sole Delta 1D-7, which was named "Golden Goose".

==Military operators==
[[File:Northrop Delta Mk1 1939.jpg|thumb|Canadian Northrop Delta in 1939]]
<!-- should be at the very least the countries where this aircraft is used. if able, include notable companies or military units that operate the aircraft -->
;{{AUS}}
*[[Royal Australian Air Force]] – Operated one impressed Delta from December 1942 to September 1943.
;{{flag|Canada|1921}}
*[[Royal Canadian Air Force]]
**[[No. 8 Squadron RCAF]]
**[[No. 119 Squadron RCAF]]
**[[No. 120 Squadron RCAF]]
;{{flag|Spain|1931}}
*[[Spanish Republican Air Force]] – ex-Swedish Northrop 1C Delta with [[LAPE]]
*Nationalist Air Force - Northrop 1D Delta captured on Mar Cantabrico
;{{USA}}
*[[United States Coast Guard]]

==Civil operators==
;{{AUS}}
* [[Civil Aviation Authority of Australia]]

;{{MEX}}
* [[Aerovias Centrales SA]] (a [[Pan-Am]] Subsidiary)

;{{SWE}}
* [[AB Aerotransport]] (now part of SAS)

;{{USA}}
* [[Trans World Airlines]] (aka TWA)
* [[Honeywell]] (executive aircraft)
* [[ARCO|Richfield]] (executive aircraft)

==Specifications (Delta 1D-5) ==
{{Aircraft specs
|prime units? = kts

|ref=McDonnell Douglas Aircraft since 1920 <ref name="Francillon p165">Francillon 1979, p.165.</ref> 
|crew=1
|capacity=8 Passengers (passenger variants)
|length ft= 33
|length in= 1
|length m=10.08 
|span ft=47
|span in=9
|span m=14.55 
|height ft=10
|height in=1
|height m=3.07 
|wing area sqft=363 
|wing area sqm=33.7 
|empty weight lb=4,504 
|empty weight kg=2,059 
|gross weight lb=7,350 
|gross weight kg=3,334 
|eng1 name=[[Wright R-1820|Wright SR-1820-F2]]
|eng1 type=Nine-cylinder air-cooled [[radial engine]]
|eng1 number=1
|eng1 hp=735 
|eng1 kw=548 
|max speed kts=190 
|max speed mph=219
|max speed kmh=352
|max speed note=at 6,300 ft (1,920 m)
|cruise speed kts=174 
|cruise speed mph=200
|cruise speed kmh=332
|range nmi=1,435 
|range miles=1,650
|range km=2,655
|ceiling ft=20,000 
|ceiling m=6,095 
|climb rate ftmin=1,200 
|climb rate ms=6.1 
|wing loading lb/sqft=20.2 
|wing loading kg/m2=98.9 
|power/mass=0.10 hp/lb (0.16 kW/kg)
|avionics=
}}

==See also==
{{Portal|Aviation}}
{{aircontent

|related=
 
*[[Northrop Alpha]]
*[[Northrop Beta]]
*[[Northrop 8A]]
*[[Northrop N-3PB]]
*[[Northrop BT-1]]
*[[Northrop Gamma]]

|similar aircraft=
* [[Airspeed Envoy]]
* [[Boeing Monomail]]
* [[Breese-Dallas Model 1]]
* [[General Aviation GA-43|General Aviation/Clarke GA-43]]
* [[Heinkel He 70]]
* [[Junkers Ju 60]]
* [[Kharkiv KhAI-1]]
* [[Lockheed Model 9 Orion]]
* [[Manshū Hayabusa]]
* [[Polikarpov R-5#Variants|Polikarpov/Rafaelyants PR-12]]
* [[Tairov OKO-1]]
* [[Vultee V-1]]
|lists= 
* [[List of aircraft of World War II]]
*[[List of aircraft of the Canadian Air Force]]

|see also=

}}

==References==
;Notes
{{Reflist}}
;Bibliography
* "[http://www.flightglobal.com/pdfarchive/view/1934/1934%20-%200123.html The Latest Northrops: The "Victoria" and "Delta" Models]". ''[[Flight International|Flight]]'', 8 February 1934. pp.&nbsp;123–124. 
* Francillon, René J. ''McDonnell Douglas Aircraft since 1920''. London:Putnam, 1979. {{ISBN|0-370-00050-1}}.
* Green, William. ''War Planes of The Second World War:Volume Seven – Bombers and Reconnaissance Aircraft''. London:Macdonald, 1967.

==External links==
{{commons category|Northrop Delta}}
*[http://www.canadianwings.com/Aircraft/aircraftDetail.php?DELTA-134 Canadianwings.com]
*[http://www.airwaysmuseum.com/Northrop%20D.1%20Delta%20VH-ADR.htm Northrop Delta VH-ADR]

{{Northrop aircraft}}
{{Canadian Vickers aircraft}}
{{USN transports}}
{{Aircraft manufactured in Canada}}
{{Spanish liaison aircraft}}
{{ADF aircraft designations}}

[[Category:1930s United States civil utility aircraft]]
[[Category:Northrop aircraft|Delta]]
[[Category:1930s United States airliners]]
[[Category:Low-wing aircraft]]
[[Category:Single-engined tractor aircraft]]
[[Category:Aircraft first flown in 1933]]
[[Category:Aircraft with fixed conventional landing gear]]
[[Category:Single-engined piston aircraft]]