Aufgrund öffentlichen Interesses poste ich mal das hier aus der großen Whif-Sammlung. Ist ja quasi SF, denn dies wird erst in ein paar Wochen Realität werden...
Ich präsentiere also die Northrop Grumman-IAI F-24A “Tigerhawk” (a.k.a. “נמר / Namer“):
Some background:The Northrop Grumman-IAI F-24 is the latest reincarnation of the USAF "Lightweight Fighter Program" which dates back to the 1950ies and started with the development of Northrop's F-5 "Freedom Fighter".
The 1st generation F-5 became very successful in the export market and saw a long line of development, including the much more powerful F-5E "Tiger II" and the F-20 Tigershark (initially called F-5G). Northrop had high hopes for the F-20 in the international market; however, policy changes following Ronald Reagan's election meant the F-20 had to compete for sales against aircraft like the F-16, the USAF's latest fighter design (which was politically favored). The F-20 development program was eventually abandoned in 1986 after three prototypes had been built and a fourth partially completed.
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But this was not the end for Northrop’s Lightweight Fighter. In the early 1980s, two X-29As experimental aircraft were built by Grumman from two existing Northrop F-5A Freedom Fighter airframes. The Grumman X-29 was a testbed for forward-swept wings, canard control surfaces, and other novel aircraft technologies. The aerodynamic instability of this arrangement increased agility but required the use of computerized fly-by-wire control. Composite materials were used to control the aeroelastic divergent twisting experienced by forward-swept wings, also reducing the weight. The NASA test program continued from 1984 to 1991 and the X-29s flew 242 times, gathering valuable data and breaking ground for new aerodynamic technologies of 4th and 5th generation fighters.
, on Flickr
, on Flickr
Even though no service aircraft directly evolved from the X-29, its innovative FBW system as well as the new material technologies also opened the door for an updated F-20 far beyond the 1990ies. It became clear that ever expensive and complex aircraft could not be the answer to modern, asymmetrical warfare in remote corners of the world, with exploding development costs and just a limited number of aircraft in service that could not generate true economies of scale, esp. when their state-of-the-art design would not permit any export.
Anyway, a global market for simpler fighter aircraft was there, as 1st generation F-16s as well as the worldwide, aging F-5E fleet and types of Soviet/Russian origin like the MiG-29 provided the need for a modern, yet light and economical jet fighter. Contemporary types like the Indian HAL Tejas, the Swedish Saab Gripen, the French Dassault Rafale and the Pakistani/Chinese FC-1/JF-17 ”Thunder” proved this trend among 4th - 4.5th generation fighter aircraft.
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Northrop Grumman (Northrop bought Grumman in 1994) initiated studies and basic design work on a respective New Lightweight Fighter (NLF) as a private venture in 1995. Work on the NLF started at a slow pace, as the company was busy with re-structuring.
The idea of an updated lightweight fighter was fueled by another source, too: Israel. In 1998 IAI started looking in the USA for a development partner for a new, light fighter that would replace its obsolete Kfir fleet and partly relieve its F-16 and F-15 fleet from interception tasks. The domestic project for that role, the IAI Lavi, had been stillborn, but lots of its avionics and research were still at hand and waited for an airframe for completion.
, on Flickr
, on Flickr
The new aircraft for the IAF was to be superior to the MiG-29, at least on par with the F-16C/D, but easier to maintain, smaller and overall cheaper. Since the performance profiles appeared to be similar to what Northrop Grumman was developing under the NLF label, the US company eventually teamed up with IAI in 2000 and both started the mutual project "Namer" (=נמר, “Tiger” in Hebrew), which eventually lead to the F-24 I for the IAF which kept its project name for service and to the USAF’s F-24A “Tigershark”.
The F-24, as the NLF, was based on the F-20 airframe, but outwardly showed only little family heritage, onle the forward fuselage around the cockpit reminds of the original F-5 design . Many aerodynamic details, e. g. the air intakes and air ducts, were taken over from the X-29, though, as the experimental aircraft and its components had been developed for extreme maneuvers and extra high agility. Nevertheless, the X-29's forward-swept wing was considered to be too exotic and fragile for a true service aircraft, but the F-24 was to feature an Active Aeroelastic Wing (AAW) system.
AAW Technology integrates wing aerodynamics, controls, and structure to harness and control wing aeroelastic twist at high speeds and dynamic pressures. By using multiple leading and trailing edge controls like "aerodynamic tabs", subtle amounts of aeroelastic twist can be controlled to provide large amounts of wing control power, while minimizing maneuver air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. This system was initially tested on the X-29 and later on the X-53 research aircraft, a modified F-18, until 2006.
Both USAF and IAF versions feature this state-of-the-art aerodynamic technology, but it is uncertain if other customers will receive it. While details concerning the F-24's system have not been published yet, it is assumed that its AAW is so effective that canard foreplanes could be omitted without sacrificing lift and maneuverability, and that drag is effectively minimized as the wing profile can be adjusted according to the aircraft’s speed, altitude, payload and mission – much like a VG wing, but without its clumsy and heavy swiveling mechanism which has to bear high g forces. As a result, the F-24 is, compared to the F-20, which could carry an external payload of about 3.5 tons, rumored to be able to carry up to 5 tons of ordnance.
, on Flickr
, on Flickr
The delta wing shape proved to be a perfect choice for the required surface and flap actuators inside of the wings, and it would also offer a very good compromise between lift and drag for a wide range of performance. Anyway, there was one price to pay: in order to keep the wing profile thin and simple, the F-24’s landing gear retracts into the lower fuselage, leaving the aircraft with a relatively narrow track.
Another major design factor for the outstanding performance of this rather small aircraft was weight reduction and structural integrity – combined with simplicity, ruggedness and a modular construction which would allow later upgrades. Instead of “going big” and expensive, the new F-24 was to create its performance through dedicated loss of weight, which was in some part also a compensation for the AAW system in the wings and its periphery.
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Weight was saved wherever possible, e .g. a newly developed, lightweight M199A1 gatling gun. This 20mm cannon is a three-barreled, heavily modified version of the already “stripped” M61A2 gun in the USAF’s current F-18E and F-22. One of the novel features is a pneumatic drive instead of the traditional electric mechanism, what not only saves weight but also improves trigger response. The new gun weighs only a mere 65kg (the six-barreled M61A2 weighs 92kg, the original M61A1 112 kg), but still reaches a burst rate of fire of 1.800 RPM (about 800 RPM under cyclic fire, standard practice is to fire the cannon in 30 to 50-round bursts, though) and a muzzle velocity of 1.050 metres per second (3,450 ft/s) with a PGU-28/B round.
While the F-16 was and is still made from 80% aluminum alloys and only from 3% composites, the F-24 makes major use of carbon fiber and other lightweight materials, which make up about 40% of the aircraft’s structure, plus an increased share of Titanium and Magnesium alloys. As a consequence and through many other weight-saving measures like keeping stealth capabilities to a minimum (even though RAM was deliberately used and many details designed to have a natural low radar signature, resulting in modest radar cross-section (RCS) reductions), a single, relatively small engine, a fuel-efficient F404-GE-402 turbofan, is enough to make the F-24 a fast and very agile aircraft, coupled with a good range. The F-24’s thrust/weight ratio is considerably higher than 1, and later versions with a vectored thrust nozzle (see below) will take this level of agility even further – with the pilot becoming the limiting factor for the aircraft’s performance.
USAF and IAF F-24s are outfitted with Northrop Grumman's AN/APG-80 Active Electronically Scanned Array (AESA) radar, also used in the F-16 Block 60 aircraft. Other customers might only receive the AN/APG-68, making the F-24 comparable to the F-16C/D.
The first prototype, the YF-24, flew on 8th of March 2008, followed by two more aircraft plus a static airframe until summer 2010. In early 2011 the USAF placed an initial order of 101 aircraft (probably also to stir export sales – the earlier lightweight fighters from Northrop suffered from the fact that the manufacturer’s country would not use the aircraft in its own forces). These initial aircraft will replace older F-16 in the interceptor role, or free them for fighter bomber tasks. The USN and USMC also showed interest in the aircraft for their aggressor squadrons, for dissimilar air combat training. A two-seater, called the F-24B, is supposed to follow soon, too, and a later version for 2020 onwards, tentatively designated F-24C, is to feature an even stronger F404 engine and a 3D vectoring nozzle.
Israel is going to produce its own version domestically from late 2014 on, which will exclusively be used by the IAF. These aircraft will be outfitted with different avionics, built by Elta in Israel, and cater to national requirements which focus more on multi-purpose service, while the USAF focusses with its F-24A on aerial combat and interception tasks.
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International interest for the F-24A is already there: in late 2013 Grumman stated that initial talks have been made with various countries, and potential export candidates from 2015 on are Taiwan, Singapore, Thailand, Finland, Norway, Australia and Japan.
General F-24A characteristics:Crew: 1 pilot
Length: 47 ft 4 in (14.4 m)
Wingspan: 27 ft 11.9 in / 8.53 m; with wingtip missiles (26 ft 8 in/ 8.13 m; without wingtip missiles)
Height: 13 ft 10 in (4.20 m)
Wing area: 36.55 m² (392 ft²)
Empty weight: 13.150 lb (5.090 kg)
Loaded weight: 15.480 lb (6.830 kg)
Max. take-off weight: 27.530 lb (12.500 kg)
Powerplant1× General Electric F404-GE-402 turbofan with a dry thrust of 11,000 lbf (48.9 kN) and 17,750 lbf (79.2 kN) with afterburner
PerformanceMaximum speed: Mach 2+
Combat radius: 300 nmi (345 mi, 556 km); for hi-lo-hi mission with 2 × 330 US gal (1,250 L) drop tanks
Ferry range: 1,490 nmi (1715 mi, 2759 km); with 3 × 330 US gal (1,250 L) drop tanks
Service ceiling: 55,000 ft (16,800 m)
Rate of climb: 52,800 ft/min (255 m/s)
Wing loading: 70.0 lb/ft² (342 kg/m²)
Thrust/weight: 1.09 (1.35 with loaded weight & 50% fuel)
Armament1× 20 mm (0.787 in) M199A1 3-barreled Gatling cannon in the lower fuselage with 400 RPG
Eleven external hardpoints (two wingtip tails, six underwing hardpoints, three underfuselage hardpoints) and a total capacity of 11.000 lb (4.994 kg) of missiles (incl. AIM 9 Sidewinder and AIM 120 AMRAAM), bombs, rockets, ECM pods and drop tanks for extended range.
Tatsächlich ist dieses Kitbashing aus einer Zusammenarbeit mit einem user auf whatifmodelers.com entstanden: der hatte Langeweile und ein Bitmap-Profile gebastelt:
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Er hatte mich spaßeshalber angepingt, ob das nicht was wäre - und ich habe, da ich viele Zutaten auf Halde hatte, zur Tat geschritten... Ideen und WiP ging hin und her, so dass sich auch das Profil verändert , bis wir bei der F-24 "Tigerhawk", a.k.a. IAI "Namer" gelandet sind:
, on Flickr
Die F-24 besteht aus:
● Rumpf, Cockpit & Fahrwerk einer Hasegawa X-29
● Finne und Nase einer Italeri F-16A
● Innere Tragflächen einer alten Hasegawa MiG-21F
● Äußere Flügel einer F-4 (verm. eine J, Hasegawa oder Fujimi)
Anstrich ist Standard Hill II, die Markierungen sind zusammengepuzzelt und "passen" zu einer Maschine der 318th FIS (USAF); McChord AFB, Tacoma - in der Nähe des Wohnortes des eigentlichen Schöpfers der Kiste. Viele Beauty Pics sind denn auch vor einem passenden Hintergrund aufgenommen.
Kollege pirx hier im Board profitiert auch davon, dazu aber mehr, wenn "der große Plan" mal aufgeht...
Thema: What if? Northrop Grumman-IAI F-24A “Tigerhawk” (a.k.a. “נמר / Namer“) (Gelesen 5481 mal)
