Northrop YA-9: Difference between revisions

|image = File:Northrop YA-9 prototype.jpg

}}{{Infobox Aircraftaircraft Typetype

|type = [[Attack aircraft]]

|manufacturer = [[Northrop Corporation|Northrop]]

|status = CanceledCancelled

|primary user = [[United States Air Force]]
|more <br/>users = [[NASA]]

The A-9 was a shoulder-wing [[monoplane]] of all-riveted [[aluminum alloy]] construction, with [[honeycomb structure]]s and [[Chemical milling|chemically milled]] skins. The required twin turbofans were fitted in nacelles under the aircraft's wing roots.{{#tag:ref|By comparison, the A-10 engine location at the tail is less conventional, but offers greater survivability in the case of a hit on the engine area. The double tail of the A-10 also hides the engine infrared and noise signature, and incorporates redundancy in case one of the tails is shot away.{{cn|date=January 2022}}|group=lower-alpha}} Northrop selected the {{convert|7200|lbf|kN|abbr=on}} [[Lycoming YF102]] engine for the YA-9 rather than the more powerful ({{convert|9280|lbf|kN|abbr=on}}) [[General Electric TF34]] used by the A-10, although either engine could be accommodated. The F-102YF102 engine was a new design, based on the [[Avco Lycoming T55|T55]] [[turboshaft]] that powered the [[Boeing CH-47 Chinook|CH-47]] helicopter, which was selected in order to minimize costs.{{sfn|Jesse|Engbrecht|1996|p=58}}{{sfn|Aviation Week|1972|p=109}} The aircraft had a large cruciform [[Stabilizer (aeronautics)|stabilizer]] in order to improve directional stability for low-level flight. Split [[aileron]]s were fitted that could be used as [[Air brake (aeronautics)|airbrake]]s. When these airbrakes were operated asymmetrically in conjunction with the aircraft's [[rudder]], sideways control forces could be applied (and the aircraft moved sideways) without [[Aircraft principal axes#Vertical axis .28yaw.29|yawing]] or [[Banked turn|banking]], easing weapon aiming.{{sfn|Jesse|Engbrecht|1996|p=58}}{{sfn|Fink|1972a|pp=45–46}}

The pilot sat under a large bubble canopy well ahead of the leading edge of the wings. The cockpit was surrounded by a bathtub of armor (aluminum in the prototypes, which would have been replaced by [[titanium]] if production occurred) while the wing-mounted fuel tanks were self-sealing and filled with foam to minimize the potential for fires or massive fuel loss. Dual redundant hydraulic flight control systems were fitted, with a further manual backup to prevent a single hit from causing control failure. These design features were hoped to reduce combat losses by as much as 90% in Vietnam-type operations.{{sfn|Jesse|Engbrecht|1996|p=58}}{{sfn|Aviation Week|1972|p=113}} A single 30&nbsp;mm [[Gatlingrotary guncannon]] was to be fitted in the belly of the aircraft, with the gun barrels extending under the nose. As the gun was mounted on the aircraft's centerline, the undercarriage nosewheel was offset {{convert|1|ft|m|spell=in}} to the left. As the [[GAU-8 Avenger]] cannon was not ready, both the YA-9 prototypes (as well asand the two YA-10s) were instead fitted with the smaller 20&nbsp;mm [[M61 Vulcan]] instead. Ten underwing [[hardpoint]]s were fitted, allowing up to {{convert|16000|lb|kg|abbr=on}} of weapons, including bombs and [[AGM-65 Maverick]] [[air-to-ground missile]]s, to be carried.{{sfn|Jesse|Engbrecht|1996|p=59}}

The YA-9 took its first flight on 30 May 1972,{{sfn|Jenkins|1998|p=26}}{{sfn|Donald|March|2004|p=9}} with the second prototype flying on 23 August.{{sfn|Jesse|Engbrecht|1996|p=59}} Northrop's flight testing was successful, with the aircraft claimed to have "fighter-like" handling and to be a good weapon platform.{{sfn|Fink|1972a|pp=44–46}} A fly-off by USAF test pilots of the two competing designs took place between 10 October and 9 December 1972.{{sfn|Fink|1972b|p=20}} While the YA-9 fully met the USAF's requirements, the YA-10 was declared the winner on 18 January 1973. The use of the established TF34 engine by the YA-10 rather than the untried F102 by the YA-10 may have been preferred by the Air Force, while Fairchild had no alternative work available and was unlikely to survive if it did not win the A-X contract.{{sfn|Jesse|Engbrecht|1996|p=59}}

[[File:Northrop YA-9A ‘11368’ (26683410563).jpg|thumb|Northrop YA-9A display at the [[March Field Air Museum]], Riverside, CA.California]]

* 71-1368 - on display at [[March Field Air Museum]], [[March Air Reserve Base]], [[California]].<ref>{{cite web |title= YA-9A |work= March Field Air Museum |url= https://www.marchfield.org/aircraft/attack/ya-9a-northrop/ |access-date= 2 March 2021}}</ref>

|ref= Airdata File: Northrop A-9A<ref name="AI972 p160">{{cite magazine sfn|title=<!-- title needed --> |magazine= ''Air Enthusiast |date='' September 1972 |pagep= 160}}</ref>

* [[Fairchild Republic A-10 Thunderbolt II]]

* [[SukhoiIlyushin SuIl-25102]]

* [[IlyushinSukhoi IlSu-10225]]

* [[List of attack aircraft]]

* [[List of military aircraft of the United States]]

{{Reflist|30em}}

* {{cite magazine |title= AXAirdata Fighter Paved Way for PrototypingFile |magazine= [[AviationAir Week and SpaceInternational|Air TechnologyEnthusiast]] |volume= 963 |issuenumber= 263 |date= 26 JuneSeptember 1972 |pages=103–104 156–160 |urlisbn= http://archive.aviationweek.com/issue/19720626/#!&pid=1020-903234-31-9 |url-accessref={{harvid|''Air registrationEnthusiast'' |ref=noneSeptember 1972}}}}

* {{cite magazine |last= Fink |first= Donald E. |year= 1972a |title= Contractors Prepare for 90-Day AX Flyoff |magazine= Aviation Week and Space Technology |volume= 97 |number= 14 |date= 2 October 1972 |pages= 44–48 |url= http://archive.aviationweek.com/issue/19721002/#!&pid=44 |url-access= registrationsubscription}}

* {{cite magazine |last= Fink |first= Donald E. |year= 1972b |title= USAF Completes AX Flight Evaluations |magazine= Aviation Week and Space Technology |volume= 97 |number= 24 |date= 11 December 1972 |page= 20 |url= http://archive.aviationweek.com/issue/19721211/#!&pid=20 |url-access= registrationsubscription}}

* {{cite magazine |title= Northrop Streamlines A-9A Management |magazine= Aviation Week and Space Technology |volume= 96 |number= 26 |date= 26 June 1972 |pages= 107–113 |url= http://archive.aviationweek.com/issue/19720626/#!&pid=106 |url-access= registrationsubscription |ref= {{sfnref|Aviation Week|1972}} }}