Northrop Grumman F-19A Specter
Development of the F-19
Loral's initial design was stealthy, but improvement using modern computers and computation converted it to a high-performance craft with a low radar profile. Small, inward-sloped vertical tails provided little stability, contributing mostly to maneuverability. Newly-designed fly-by-wire computers, later applied to the completely-tailless Northrop-Boeing B-2 Spirit, counteracted the reduced stability. The adapted delta-wing configuration helped as well; inherently more stable than standard swept-wing configurations, the wings curved down at the tips, creating an additional slightly vertical surface for added stability. Small unmovable canards were built into the body to break up the straight leading edge of the craft, provide some lift, and guide air to the engine inlets at low angles of attack.
The air inlets, as in the Northrop's XST submission, are located on top of the craft and to the rear of the pilot. This prevents radar reflection off compressor blades from being visible to ground-based radar installations. RAM-coated angular 'vents' in front of the compressors scatter radar reflections to other aircraft. Cold War requirements for the interceptor included in-air refueling; the best place for the Northrop designers to position the inlet was behind the pilot, but directly in front of the intake vents. Small amounts of fuel spilled during refueling are immediately sucked into the engine causing a small burst of power and making the F-19 lurch slightly, much to the concern of the nearby inflight-refueling crews on the tanker.
A most creative solution to Infra-red signatures is the pass-through exhaust air scoop. Below the engine outlets, on the underside of the craft, the F-19 has airscoop 'rams' that force unheated air from beneath the aircraft upwards, passing through the plane itself, into the exhaust stream of the engines. This allows the craft to operate with afterburners, because the cooling effect is proportional to the aircraft's speed. The scoops do create a downward force on the rear of the craft, forcing the nose up slightly, but the fly-by-wire systems account for it and it assists in lift during high-altitude flight. As these 'rams' are passive, the vents are closed from above whenever the engines are in operation while the craft is stationary, such as taxiing or warming up, to prevent exhaust gases from being forced the wrong way out the rams and endangering ground crew.
The craft was built without a machine gun, under the assumption that at such high speed engagements the gun would be useless. The craft has four internal hardpoints hidden within the body of the craft that could be used to carry a machine gun pod, hiding its reflectivity and heat when the ordinance bay is closed. The hardpoints may carry any combination of air-to-air armament. The small payload is considered the plane's greatest drawback, although the need for more than four missiles was never tested.
The low side profile of the craft forces the pilot into a reclined seating position; this is actually an advantage for the pilot, because it reduces the possibility of blacking out during high-G turns.
Northrop Grumman F-19 Specter Specifications:
Max T/O Weight
Max Ferry Range
....4 x AIM-120-W93-SP, 2 x GBU-15, M61 Vulcan, Also capable of carrying Exocet/Sidewinder/Sparrow/Skyflash Missiles.
Fire Control System...................... AN/APQ-125C with
cryogenically cooled infra-red and temporal/magnetic search
and track fire control functions.
2 x Pratt and Whitney F100 with 27,000 lb thrust each, or 2 x SNECMA M53-P2.
F/A-18 Hornet/SEPECAT Jaguar.
Cyano-acrylically bonded graphite/
epoxy fuselage and wing, titanium
engine nacelles, Lumispex-coated
canopy, all sheathed by classified
..1 in D model, 2 in E model.