Dassault Mirage III (Part 2) Progeny: The Cheetah and Kfir

Mirage III Progeny: The Cheetah program


During the early 1980's, the SAAF faced modern Soviet aircraft and weapons in Angola. Being handicapped by a UN arms embargo, the SAAF had to act urgently to improve its capabilities. 
The SAAF never had a large number of combat aircraft to spare. It only had about forty combat-ready 1970's-vintage Mirage F1's. If it was to take them out of service to upgrade them, it had no replacement other than the  even older, 1960's-vintage Mirage III's. These were shorter-ranged, had less powerful engines and obsolete combat systems, and could carry less ordnance. This meant any upgrade would have to be applied first to the older Mirage III's, as they were the only aircraft that could be spared from combat operations for that purpose.

Fortunately, this wasn't a bad choice in the end. Two major aircraft programs had demonstrated what could be done by building on the foundation of the Mirage III, probably one of the most successful proven combat aircraft of it's day. First, Dassault Aviation was by then producing the successor to the Mirage F1, the Mirage 2000, which returned to the delta-wing format of the Mirage III.

Mirage III D

Israel agreed to supply systems and components, and the green light for the Cheetah project was given in the early 1980's. In order to provide a measure of diplomatic and political 'cover' for Israel, it was decided (as with  many South African weapons projects) to claim that it was an purely indigenous development. Despite huge similarity between the Kfir and the Cheetah, officials in on both sides  steadfastly deny that the two aircraft had anything in common. 

The SAAF provided Israel a two-seat Mirage IIID as the prototype air frame for conversion. It was stripped down completely and all components subject to metal fatigue or stress were replaced, effectively returning the air frame new condition. An extended nose cone was fitted, derived from the Kfir TC.2 model, which housed advanced electronic systems, and small canard wings were fitted above the air intakes to improve low-speed handling and angle of attack. (The canards on the D and E model Cheetahs were smaller than those used on the later Cheetah C's, reportedly because it was too difficult to reinforce the fuselage frames in the engine intake area to accommodate the larger units. The Cheetah C's used the same full-size canards as the Kfir; but their air frames were supplied by Israel, as noted below. Presumably they weren't subject to the same limitations as the French-air frame-based Cheetah D's and E's.)

Israel Aircraft Industries (IAI), together with several other companies in that country's defense industry, had already produced a series of Mirage derivatives. Israel had purchased Mirage III aircraft from France prior to the Six-Day War of 1967, and had ordered a further 50 Mirage 5's (a simplified version of the Mirage III). However, these were embargoed by France after the conflict. Undaunted, Israel stole the plans to the Mirage III from Switzerland, which was license-manufacturing the aircraft (Swiss engineer, Alfred Frauenknecht, would later be sentenced to 4½ years imprisonment for his collaboration with Israel).

Israel used these plans to develop its own fighters. The first  was the Nesher, almost an exact copy of the Mirage 5 (indeed, it's so exact that some sources suggest IAI actually assembled Mirages, clandestinely supplied in kit form by France, rather than manufactured the Nesher itself). A total of 60 Neshers appear to have been manufactured, most sold to Argentina at the end of the 1970's under the name of Dagger 

These aircraft confronted British forces during the Falklands War. Israel went on to produce the Kfir, a considerably upgraded Mirage derivative with Israeli electronics with a US J79 turbojet engine (As on the F-4 Phantom II fighter-bomber, also operated by Israel at the time).

Argentine "Dagger"

The IAI Nammer ("Leopard",  frequently mistranslated as "Tiger") was a fighter aircraft developed in Israel in the late 1980s/1990s as a modernised version of the Kfir for the export market. Although a prototype was built and flown, buyers were not forthcoming and development was ceased. The avionics of the Nammer were those of the cancelled Lavi project.

The Nammer promised an upgrade package for existing Mirage III and Mirage 5 air frames. Two configurations were proposed, one based around re-engining with a General Electric F404, the other around retaining the Mirage's SNECMA Atar engine. Elta EL/M-2011 or EL/M-2032 fire-control radar was to be fitted. The first of these options maximised performance and range, the second maximised the aircraft's air-to-air targeting capability. As development progressed, the Nammer came to be advertised as a new-build aircraft with the EL/M-2032 an integral part of the package, and customers able to choose their preferred engine out of the F404 (or its Volvo derivative, the RM-12), the SNECMA M53, or the Pratt & Whitney PW1120. The design strongly resembled the Kfir C-7,but was easily distinguished by its longer nose and lack of a dorsal air scoop under the tail fin

Details of the weapon and control systems fitted to the Cheetah have never been publicly revealed by the SAAF, but it can probably assumed they were close to or identical to those found on various models of the Kfir. IAI lists them as including, in the latest Kfir version:

The radar used in the Cheetah D and E models (and in the Kfir C.7) was the simple Elta EL/M-2001Bunit. The Cheetah C, the last development of this project, possibly had the much more advanced Elta EL/M-2032 . The Cheetah C's electronic systems were probably on a par with those of the F-16C/D fighter-bombers of the USAF at the time.

The intermediate single-seat Cheetah E model:

Here's the final iteration of the Cheetah, the 'C' model:

The SAAF's two-seat Mirage IIID variants were the first to be converted. This was probably for two reasons. First, and most pragmatically, the two-seat air frames could be most easily spared from operational duties. Second, they were probably urgently needed to replace the worn-out two-seat Buccaneer aircraft in the nuclear strike role (South Africa had six nuclear weapons, developed at the height of its political isolation and military struggle, which were dismantled in the early 1990's). The Buccaneers had not been updated with modern strike systems, which limited their usefulness; so the upgraded Cheetah D's would have been welcome in this role.

Sixteen two-seat Cheetah D's were produced, as well as 16 single-seat Cheetah E's, the latter mostly converted from Mirage IIIEZ air frames (although some were reportedly converted from air frames supplied by Israel, due to a shortage of suitable South African Mirages). All had been delivered by 1991. Finally, 38 Cheetah C's were produced under the auspices of 'Project Tunny'. 
The Cheetah C's were reportedly based on stripped down Kfir air frames supplied by Israel, modified to accept the French Atar engine rather than the US J79.  Most of the SAAF's Mirage III's had been delivered during the 1960's. Some had reached the end of their fatigue lives, and were thus unsuitable for conversion. Others had been lost in accidents, and the Cheetah E conversions had absorbed many of the remainder.

Given these two facts, there would not have been enough usable single-seat Mirage III air frames left in the SAAF inventory to produce 38 Cheetah C's.  one can safely assume that the reports that say Israel supplied the fuselages for the latter is accurate. Apart from the prototype Cheetah D, most of the conversions were carried out in South Africa by Atlas Aircraft Corporation (today part of Denel Aviation), with Israeli technical assistance (which decreased as local industry gained experience and competence).

The C models were delivered from 1993-1995, replacing the Cheetah E's, which were retired. Some of the two-seat Cheetah D's were retained in service as lead-in trainers for the C versions, and to provide a specialist strike function if required. A single experimental Cheetah R version was produced, using a Mirage IIIR2Z airframe, but no other reconnaissance versions were converted, and the Cheetah R did not enter squadron service, being retired soon afterwards. The reconnaissance function was taken over by Cheetah C's fitted with pod-mounted cameras.

The first ACW prototype was tested on the only Cheetah R, and a more evolved model was tested on a two-seat Cheetah D. The latter improved the Cheetah's sustained turn rate by 14%, and permitted maximum takeoff weight to be increased by well over half a ton. It also permitted angles of attack up to 33 degrees at low speeds, with much greater stability, at the expense of a reduction of approximately 5% in the aircraft's maximum supersonic speed. However, for budgetary reasons the SAAF declined to upgrade their Cheetahs with the ACW, and it was never put into production.


If it lost aircraft due to combat or accident  it could not replace them, due the embargo; and it had to keep its combat planes as up-to-date as possible, to ensure they did not become so obsolete that they risked being shot down in large numbers by more advanced enemy aircraft. 

Mirage 2000-5F of the French Air Force

South Africa had friendly ties with Israel, particularly in the military field.  South African technological institutions such as the Council for Scientific and Industrial Research (CSIR), and local defense companies such as Kentron (today Denel Dynamics), Reutech and others, were developing advanced radar and electro-optical detection and guidance systems. The latter companies in particular often collaborated with their Israeli counterparts (up to and including producing Israeli components and systems under license in South Africa). It would therefore be entirely feasible for the advanced combat systems of the Kfir to be 'transplanted' into the Mirage III's of the SAAF, including local assembly and partial production if necessary.

AI Kfir, in US Navy colors under the designation F-21A,

where it served as an adversary aircraft for Dissimilar Air Combat Training

The Cheetah had a considerably more powerful and more economical engine, greatly improved avionics and weapons systems, and a fly-by-wire control system, which rendered it far superior to the Mirage III from which it stemmed. (It's generally accepted that the French Mirage 2000 is roughly comparable, in terms of its overall capability, to contemporary models of the US F-16 Fighting Falcon or the Soviet MiG-29.) The SAAF reasoned that if Dassault could develop the Mirage III into a fully modern warplane, they could do likewise. This was aided by the fact that in the 1970's, South Africa had purchased a license to manufacture the Mirage III and F1, as well as the latter's Atar 09K-50 turbojet engine. All the necessary plans were thus already on hand.



Given that the Cheetah prototype was converted in Israel, it's very interesting to note the proposed IAI Nammer aircraft of the late 1980's. Wikipedia info:




You can't help but notice that the line drawing above is virtually identical to the pictures of the Cheetah C and Kfir 2000 . Also note that the translation of 'Nammer' is the name of a big cat. A co-incidence? Did the prototype' of the Nammer become the prototype SAAF Cheetah C ?  It would certainly have been a good cover story to disguise IAI's involvement with the latter program. 

SAAF Cheetah C in Service Ysterplaat AFB

Pilot friendly advanced "Glass" Cockpit;Hands On Throttle And Stick (HOTAS) operation;
Advanced multi-mode Fire Control Radar (FCR) with SAR; State-of-the-art weapons delivery, including Beyond Visual Range missiles; Digital Moving Map (DMM); Electronic Warfare (EW) Suite.


The Israeli lineage of the Cheetah is clearly demonstrated by comparing the aircraft side-by-side. The SAAF Cheetah D, the initial two-seat version of the aircraft:

Kfir TC.2 of the Israeli Air Force:




Note identical extended and slightly downward-sloping nose cones, housing the electronics; the canard wings above the engine air intakes; and the strakes on the nose cone. Note the second curved strake running from the base of the nosecone down and back along the bottom of the fuselage. The Cheetah has an air refueling probe on the starboard side of the cockpit, which is absent from the Kfir TC.2, but an identical probe may be seen on other Kfir models, as shown below. The rear fuselage is different as the Cheetah uses a French Atar engine, while the Kfir uses the US turbojet; but from the engine forward, there's virtually no difference.


And the single-seat Kfir C.7:

Note that both have small strakes at the tip of the nose cone, identical instrument probes beneath it, and an in-flight refueling probe that goes to the starboard air intake, rather than behind the cockpit, as in the later Cheetah C. The Cheetah E also incorporates the Kfir C.7's additional two weapons stations beneath the air intakes. I therefore consider the Cheetah E and the Kfir C.7 to be essentially identical from the engine forward.



      IAI publicity photograph of their Kfir 2000 


The refueling probes are different, but the noses of the two aircraft are, again, almost identical. (Note, too, their similarity to the IAI Nammer mentioned above.) As far as its weapons and electronic systems are concerned, the Cheetah C is the functional equivalent of the Kfir 2000 (also known as the Kfir C.10.

The first sixteen Mirage III's supplied to the SAAF were 'C' model interceptors, with a shorter fuselage than subsequent models - too short to be converted into Cheetah C's, which have a longer fuselage. They could not have been lengthened without a reconstruction so extensive (and expensive) that it would have effectively meant producing a new air frame.

Vinten Vicon 18 Series 601 reconnaissance pod mounted beneath a Cheetah C

Some of the Cheetah D aircraft had been converted from Mirage IIID2Z airframes, which had been delivered with Atar 09K-50 engines in the 1970's. Naturally, they retained these more powerful engines in their Cheetah guise. The remainder of the D's, and the Cheetah E models converted from Mirage IIIE's, retained their 1960's-vintage Atar 09C turbojet engine, as local production of the more powerful Atar 09K-50 (used in the Mirage F1) had proved economically unfeasible - South Africa's technological base was insufficiently advanced to manufacture all of the required components. In any event, due to changing circumstances , the lower-powered Cheetah models would all be retired within a few years.

Efforts were mounted to obtain additional 9K-50 engines to equip the Cheetah C models. The Mirage F1 was operated by a number of other countries, including Jordan, Iraq, Morocco and Qatar, all of whom also purchased armaments from South Africa. It is possible that one or more of those nations made Atar 9K-50 engines available to South Africa in return for arms shipments. The most likely candidate would have been  Iraq.

They bought over 80 Mirage F-1's from France, and, as mentioned above, obtained 100 G5 howitzer cannon from South Africa. (Iraq was engaged in a war with Iran from 1980-1988). 

Since combat operations would naturally impose greatly increased wear on the engines of its aircraft, it could order large numbers of replacement engines without arousing suspicion. I have little doubt that some of these replacements were swapped for South African artillery and/or ammunition - probably at a very favorable 'rate of exchange', because South Africa needed the engines very badly.)

The retirement of the SAAF's Mirage F1 fleet in the 1990's was partly (although by no means exclusively) caused by the need to transplant at least some of their engines into the Cheetah fleet. The surviving F1CZ interceptors were retired in 1992. 

Some of their engines went into the Cheetah C program. The Cheetah D and E versions (which had all entered service by 1992) took over from them until the Cheetah C's were ready. The last of the Mirage F1AZ's were retired in 1997, after all the Cheetah C's had entered service.

Mirage F1

If the Cheetah aircraft had a major weakness, it was their engines. The Atar 9C engines used by Mirage III's were rated at a maximum of 13,240 pounds static thrust with afterburner. The Atar 9K-50 engine of the Mirage F1 was rated at 15,873 pounds static thrust with afterburner, an increase in power of almost 20%. 

The core technology of both these engines was based on the German BMW 003 axial-flow turbojet developed during World War II, and was becoming increasingly dated. Technology that old simply couldn't keep pace with more modern developments. The Atar 9-series turbo jetengines weren't nearly as powerful (or as economical) as the turbofan engines installed in more modern military aircraft such as the F-16 or the MiG-29 (using two Klimov RD-33 turbofans, each rated at 18,285 pounds static thrust with afterburner. Such engines weren't available to South Africa at the time the Cheetah program was developed, so the SAAF had to make do with what it could get.

The Cheetahs used an upgraded wing, offering improved aerodynamic qualities compared to that originally fitted to the Mirage III. The wing design from the Carver program was experimentally adapted to fit the Cheetahs as the Advanced Combat Wing, or ACW. The diagram below shows how more advanced Cheetah wings evolved, from the initial production variant to a final design with missile stations on the wingtips. The ACW was flight-tested, but never entered service. 



The ACW had a fixed, drooped leading edge. An early iteration (Version 2 as shown above) had a simple notch in the leading edge at mid-span, while a later model (Version 3 above) had a much wider slot. This permitted underwing mounting of the SAAF's standard 500-liter (about 132 US gallon) drop tanks, which would otherwise have struck the lowered leading edge. Additional fuel tanks were incorporated into the drooped leading edge, which were claimed to improve the Cheetah's radius of action by almost 100 kilometers (just over 60 miles).

Official and unofficial South African sources claim that the Cheetahs were very successful, and popular with their pilots. Compared to the earlier Mirage III's and F1's, this is probably true. 
The Cheetah C's were  more capable than anything preceding them in the SAAF inventory. In terms of their electronics and weapons systems, they could certainly have matched the 1980's-vintage MiG-23's and -27's, and Sukhoi Su-20/22's, that the SAAF encountered in Angola. 

Due to the lower power of their engines, I don't believe they could have matched the Soviet aircraft in acceleration or top speed. One cannot believe claims from some South African sources that the Cheetah C was comparable in performance to the US F-15 Eagle. 

SAAF Cheetah C over USS Forrest Sherman, Cape Town 2007

Despite its limitations, the Cheetah program was a success, albeit at a very high price. Including all research, development, tooling, purchase and production expenses, and averaging them across the 71 aircraft produced (16 D's, 16 E's, 38 C's and a single R - the latter not entering service), each Cheetah cost South Africa well over twice the price of a brand-new contemporary equivalent (e.g. the Mirage 2000) on the open market. Operating in a sanctions environment, there was no alternative. 

The program updated obsolete third-generation jet combat aircraft to fourth-generation standards as far as their weapons and electronic systems were concerned, and provided the SAAF with an aircraft capable of handling any regional threat at the time. Fortunately, with the end of the Angolan War in the late 1980's, the collapse of the Soviet Union in the early 1990's, and the end of apartheid in 1994, no more sophisticated threats arose that would have required a more technologically advanced response.

During the 1990's the SAAF found itself in a budgetary crisis. Not surprisingly, the first democratically-elected post-apartheid government prioritized restoring balance to political, economic and social structures Funding was directed largely to such efforts. Furthermore, the military threats facing the country had almost completely evaporated, compared to the days of the Border War and international sanctions, which had driven the Cheetah program from its inception. 

There was no longer a pressing need for combat aircraft, but a need to conserve the SAAF's much more restricted budget. The number of front-line aircraft was therefore slashed. Only one squadron was retained, operating 28 Cheetahs (a mixture of single-seat C's and two-seat D's, all powered by Atar 09K50 engines). The remainder of the Cheetah fleet was retired from SAAF service. A couple were used as development aircraft, but most were placed in storage. Some were later sold to other nations. The last Cheetahs were retired in 2008, and are presently being replaced by 26 Saab Gripen multi-role fighters.

SAAF Saab Gripen fighters

Sadly, these reductions in force and budgetary constraints caused major problems for the SAAF in retaining the services of its highly qualified and skilled pilots. Many of them saw no future for themselves in the new climate of politically correct restructuring, and resigned to pursue more lucrative opportunities elsewhere. Some became mercenary pilots of combat aircraft for other nations and/or organizations, where their superior flying skills and combat experience were greatly appreciated and well compensated. 

The SAAF's budgetary and personnel problems have not abated since. It has been rumoured that only 8 trained pilots for its Saab Gripen fighters remain , down from 30 pilots in 2005 and 20 in 2008. 

The SAAF is presently in the midst of a crisis as far as trained personnel are concerned . . . a very sad situation for a service that only two decades ago boasted pilots equal to, if not better than, those of most first-class air forces, including the USAF. The SAAF will probably never regain the very high standards it had attained by the end of the Border War in the 1980's.

And the sad end of the road for some Cheetahs:

More info on SAAF Mirages:

The Mirage F1 (click to follow links) 3 Parts, including the Border war:
Part 1 History of the F1
Part 2 The Border War: F1s in Combat
Part 3 Combat record and First Hand Account (Arthur Piercy)

(Source Wings and Wiki, other Internet sources. Not for gain, just a fan blog. No copyright infringement intended)

Horten Ho 229 Flying Wing

Horten Ho 229 Flying Wing

Role: Fighter/Bomber
Manufacturer :Gothaer Waggonfabrik
Designer: Horten brothers
First flight: 1 March 1944
Primary user: Luftwaffe
Number built: 3

The Horten H.IX, RLM designation Ho 229 (often wrongly called the Gotha Go 229 due to the identity of the chosen manufacturer of the aircraft) was a German prototype fighter/bomber designed by Reimar and Walter Horten and built by Gothaer Waggonfabrik late in World War II. It was the first pure flying wing powered by jet engines.

It was given the personal approval of Reichsmarschall Hermann Göring, and was the only aircraft to come close to meeting his "3×1000" performance requirement of 1943 (see later)

Since the appearance of the B-2 Spirit flying wing stealth bomber in the 1990s, its similarities in role and shape to the Ho 229 has led many to retrospectively describe the Ho 229 as "the first stealth bomber".

 A static reproduction of the only surviving Ho 229 prototype, the Ho 229 V3, in American hands since the end of World War II was later tested by the US military who found the basic shape and paint composition of the mock copy would provide for 20% reduction in detection range against the Chain Home radar of the 1940s, but no significant stealth benefit against most other contemporary radar systems.

Design and development

In the early 1930s, the Horten brothers had become interested in the flying wing design as a method of improving the performance of gliders. The German government was funding glider clubs at the time because production of military and even motorized aircraft was forbidden by the Treaty of Versailles after World War I.
The flying wing layout removes any "unneeded" surfaces and, in theory at least, leads to the lowest possible weight. A wing-only configuration allows for a similarly performing glider with wings that are shorter and thus sturdier, and without the added drag of the fuselage. The result was the Horten H.IV.

In 1943,  Göring issued a request for design proposals to produce a bomber that was capable of carrying a 1,000 kilograms (2,200 lb) load over 1,000 kilometres (620 mi) at 1,000 kilometres per hour (620 mph); the so-called "3 X 1000 project".

Conventional German bombers could reach Allied command centers in Great Britain, but were suffering devastating losses from Allied fighters. At the time, there was no way to meet these goals — the new Junkers Jumo 004B turbojets could provide the required speed, but had excessive fuel consumption.

The Hortens concluded that the low-drag flying wing design could meet all of the goals: by reducing the drag, cruise power could be lowered to the point where the range requirement could be met. They put forward their private project, the H.IX, as the basis for the bomber. The Government Air Ministry (Reichs Luftfahrt Ministerium) approved the Horten proposal, but ordered the addition of two 30 mm cannons, as they felt the aircraft would also be useful as a fighter due to its estimated top speed being significantly higher than that of any Allied aircraft.

The H.IX was of mixed construction, with the center pod made from welded steel tubing and wing spars built from wood. The wings were made from two thin, carbon-impregnated plywood panels glued together with a charcoal and sawdust mixture. The wing had a single main spar, penetrated by the jet engine inlets, and a secondary spar used for attaching the elevons. It was designed with a 7g load factor and a 1.8 x safety rating; therefore, the aircraft had a 12.6g ultimate load rating.

The wing's chord/thickness ratio ranged from 15% at the root to 8% at the wingtips. The aircraft utilized retractable tricycle landing gear, with the nose gear on the first two prototypes sourced from a He 177's tail wheel system, with the third prototype using an He 177A main gear wheel rim and tire on its custom-designed nose gear strut work and wheel fork.

A drogue parachute slowed the aircraft upon landing. The pilot sat on a primitive ejection seat. It was originally designed for the BMW 003 jet engine, but that engine was not quite ready and the Junkers Jumo 004 engine was substituted. nd more graceful control of yaw than would a single spoiler system.[1]

The first prototype H.IX V1, an unpowered glider with fixed tricycle landing gear, flew on 1 March 1944. Flight results were very favorable, but there was an accident when the pilot attempted to land without first retracting an instrument-carrying pole extending from the aircraft. The design was taken from the Horten brothers and given to Gothaer Waggonfabrik. The Gotha team made some changes: They added a simple ejection seat, dramatically changed the undercarriage to enable a higher gross weight, changed the jet engine inlets, and added ducting to air-cool the jet engine's outer casing, so as to prevent damage to the wooden wing.

The H.IX V1 was followed in December 1944 by the Junkers Jumo 004-powered second prototype H.IX V2; the BMW 003 engine was preferred, but unavailable. Göring believed in the design and ordered a production series of 40 aircraft from Gothaer Waggonfabrik with the RLM designation Ho 229, even though it had not yet taken to the air under jet power. The first flight of the H.IX V2 was made in Oranienburg on 2 February 1945.

All subsequent test flights and development were done by Gothaer Waggonfabrik. By this time, the Horten brothers were working on a turbojet-powered design for the Amerika Bomber contract competition, and did not attend the first test flight. The test pilot was Leutnant Erwin Ziller. Two further test flights were made between 2 and 18 February 1945. Another test pilot used in the evaluation was Heinz Scheidhauer.

The H.IX V2 reportedly displayed very good handling qualities, with only moderate lateral instability (a typical deficiency of tailless aircraft). While the second flight was equally successful, the undercarriage was damaged by a heavy landing caused by Ziller deploying the brake parachute too early during his landing approach. There are reports that during one of these test flights, the H.IX V2 undertook a simulated "dog-fight" with a Messerschmitt Me 262, the first operational jet fighter and that the H.IX V2 outperformed the Me 262.

Cockpit

Two weeks later, on 18 February 1945, disaster struck during the third test flight. Ziller took off without any problems to perform a series of flight tests. After about 45 minutes, at an altitude of some 800 m, one of the Jumo 004 turbojet engines developed a problem, caught fire and stopped. Ziller was seen to put the aircraft into a dive and pull up several times in an attempt to restart the engine and save the precious prototype.

 Ziller undertook a series of four 360-degree turns with the wings banked 20 degrees. Ziller did not use his radio or eject from the aircraft. He may already have been unconscious as a result of the fumes from the burning engine. The aircraft crashed just outside the boundary of the airfield. Ziller was thrown from the aircraft on impact and died from his injuries two weeks later. The prototype aircraft was completely destroyed.

Despite this setback, the project continued with sustained energy. On 12 March 1945, the Ho 229 was included in the Jäger-Notprogramm (Emergency Fighter Program) for accelerated production of inexpensive "wonder weapons". The prototype workshop was moved to the Gothaer Waggonfabrik (Gotha) in Friedrichroda. In the same month, work commenced on the third prototype, the Ho 229 V3.

The V3 was larger than previous prototypes, the shape being modified in various areas, and it was meant to be a template for the pre-production series Ho 229 A-0 day fighters, of which 20 machines had been ordered. The V3 was meant to be powered by two Jumo 004C engines with 10% greater thrust each than the earlier Jumo 004B production engine used for the Me 262A and Ar 234B, and could carry two MK 108 30mm cannon in the wing roots. Work had also started on the two-seat Ho 229 V4 and Ho 229 V5 night-fighter prototypes, the Ho 229 V6 armament test prototype, and the Ho 229 V7 two-seat trainer.
During the final stages of the war, the U.S. military initiated Operation Paperclip, an effort to capture advanced German weapons research, and keep it out of the hands of advancing Soviet troops.

A Horten glider and the Ho 229 V3, which was undergoing final assembly, were secured for sending to the United States for evaluation. En route, the Ho 229 spent a brief time at RAE Farnborough in the UK while it was considered if British jet engines could be fitted, but the mountings were incompatible due to the available British engines of the time only using centrifugal compressors with their comparatively larger diameter compressor sections, and not the slimmer axial-flow turbojet power plants the Germans were using.

When U.S. troops captured Gotha's Friedrichsroda plant on April 14, 1945, the partly completed Ho 229 V3 was found and transported to the U.S. and, as shown here, was held in storage at NASM's Silver Hill facility.

Survivors
The only surviving Ho 229 airframe, the V3 — and indeed, the only surviving German jet prototype still in existence — is at the Smithsonian National Air and Space Museum's Paul E. Garber Restoration Facility in Suitland, Maryland. In December, 2011, the National Air and Space Museum had moved the Ho 229 into the active restoration area of the Garber Restoration Facility and is currently being reviewed for full restoration and display. The center section of the V3 prototype was meant to be moved to the Smithsonian NASM's Steven F. Udvar-Hazy Center in late 2012 to commence a detailed examination of it before starting any serious conservation/restoration efforts

Stealth technology 
After the war, Reimar Horten said he mixed charcoal dust in with the wood glue to absorb electromagnetic waves (radar), which he believed could shield the aircraft from detection by British early warning ground-based radar that operated at 20 to 30 MHz (top end of the HF band), known as Chain Home.
A jet-powered flying wing design such as the Horten Ho 229 will have a smaller radar cross-section than conventional contemporary twin-engine aircraft. This is because the wings blended into the fuselage and there were no large propeller disks or vertical and horizontal tail surfaces to provide a typical identifiable radar signature.

Engineers of the Northrop-Grumman Corporation had long been interested in the Ho 229, and several of them visited the Smithsonian Museum's facility in Silver Hill, Maryland in the early 1980s to study the V3 airframe. A team of engineers from Northrop-Grumman ran electromagnetic tests on the V3's multilayer wooden center-section nose cones. The cones are three quarters of an inch (19 mm) thick and made up of thin sheets of veneer. The team concluded that there was indeed some form of conducting element in the glue, as the radar signal attenuated considerably as it passed through the cone.



Northrop-built reproduction 
In early 2008, Northrop-Grumman paired up television documentary producer Michael Jorgensen, and the National Geographic Channel to produce a documentary to determine whether the Ho 229 was, in fact, the world's first true "stealth" fighter-bomber. Northrop-Grumman built a full-size non-flying reproduction of the V3, constructed to match the aircraft's radar properties. After an expenditure of about US$250,000 and 2,500 man-hours, Northrop's Ho 229 reproduction was tested at the company's classified radar cross-section (RCS) test range at Tejon, California, where it was placed on a 15-meter (50 ft) articulating pole and exposed to electromagnetic energy sources from various angles, using the same three frequencies in the 20–50 MHz range used by the Chain Home in the mid-1940s.



RCS testing showed that a hypothetical Ho 229 approaching the English coast from France flying at 885 kilometres per hour (550 mph) at 15–30 metres (49–98 ft) above the water would have been visible at a distance of 80% that of a Bf 109. This implies a frontal RCS of only 40% that of a Bf 109 at the Chain Home frequencies. The most visible parts of the aircraft were the jet inlets and the cockpit, but caused no return through smaller dimensions than the CH wavelength. Given the high-speed capabilities of the aircraft it would have given the British defences just two and a half minutes to respond, which would not have been enough time. It is believed that, if deployed in great numbers, the Ho 229 could have changed the course of the war.

With testing complete, the reproduction was donated by Northrop-Grumman to the San Diego Air and Space Museum.

Link to doco on Youtube: http://www.youtube.com/watch?v=NaJzKjtjZnY

The television documentary, Hitler's Stealth Fighter (2009), produced by Myth Merchant Films, featured the Northrop-Grumman full-scale Ho 229 model as well as CGI reconstructions depicting a fictional wartime scenario where Ho 229s were operational in both offensive and defensive roles.



Data from The Great Book of Fighters:

General characteristics
Crew: 1
Length: 7.47 m (24 ft 6 in)
Wingspan: 16.76 m (55 ft 0 in)
Height: 2.81 m (9 ft 2 in)
Wing area: 50.20 m² (540.35 ft²)
Empty weight: 4,600 kg (10,141 lb)
Loaded weight: 6,912 kg (15,238 lb)
Max. takeoff weight: 8,100 kg (17,857 lb)
Powerplant: 2 × Junkers Jumo 004B turbojet, 8.7 kN (1,956 lbf) each
Performance
Maximum speed: 977km/h (607 mph) at 12,000 metres (39,000 ft)
Service ceiling: 16,000 m (52,000 ft)
Rate of climb: 22 m/s (4,330 ft/min)
Wing loading: 137.7 kg/m² (28.2 lb/ft²)
Thrust/weight: 0.26
Armament
Guns: 4 × 30 mm MK 108 cannon
Rockets: R4M rockets
Bombs: 2 × 500 kilograms (1,100 lb) bombs
See also [edit]

Sounces: Internet, Wikipedia, at al

SAAF Mirage F1 (Part 1)

Mirage F1 Development History and SAAF Early Days

Development: 

  The Mirage F1 came about as successor to the Mirage III for the French Air Force in the late 1960s.

A variety of new technologies were evaluated and tested including vertical take-off and swing-wing configurations. Dassault Industries developed the F1 as a private venture, providing a cheaper multi-purpose aircraft, designed to obtain the best operational radius and efficiency and offering the widest versatility possible at the time..

The idea was that even a small fleet of these aircraft should represent an important military threat, as later proved later in Angola! It was to be able to operate from remote and short rough air strips, with a  low landing speed (145 knots). It needed comparatively little ground equipment, and had a self starter. It offered a short turn-around time of about 15 minutes between two identical missions, and pressure refueling took only six minutes! An engine change involving four men took only about three hours.

The SDAP automatic testing unit enabled automatic trouble shooting in the field. The GAMO alert unit allowed the Mirage F1 to be scrambled in less than 2 minutes. Thus it was to prove an ideal 'Bush' warfare aircraft capable of operating for extended periods away from it’s home base, as was the case for the SAAF operating in Namibia.

Prototypes:
The French Mirage F1C prototype first flew on the 23rd of December 1966 at Melun-Villaroche, piloted by Dassault chief pilot, René Bigand, reaching Mach 2 on the 4th flight.

Flight trials continued until, during a low-altitude high-velocity pass, the horizontal stabilizers of Mirage F1-01 broke away due to a divergent vibration phenomenon called ‘flutter’ and the aircraft struck the ground near Fos-sur-Mer, killing René Bigand. Despite the accident, notification was given of an order for three pre-production aircraft: the Mirage F1-02, 03 and 04 with the Atar 9 K 50 jet engine.

During September 1967, the French Air Force expressed interest on the Mirage F1C as an all weather interceptor, carrying the Cyrano IV radar. The second prototype F1-02 first flew in March 1967 and the third in September 1969. On the 17th June 1970, the final prototype F1-04 flew. This became the production version.

Characteristics and performance
Wingspan	8.40 m
Length	15 m
Weight
Unladen	7 400 kg
Performance
Max. Speed	> Mach 2	Top mach level flight
Max. height	18 500 m / 60 700 ft	Practical ceiling
Engine
Type	Snecma Atar 9 K 50 70.6 kN

French Combat Experience:
The French Air Force Mirage F1C first saw combat during Operation Manta in August 1983, strafing an enemy column. The French intervened in the Chad, to counter growing Libyan encroachment. Four Mirage F1C-200s provided air cover for a force of four Jaguars, and took part in skirmishes against the pro-Libyan GUNT rebels.


In 1986, French Mirage F1s returned to Chad, as part of Operation Epervier, with four F1C-200s providing fighter cover for a strike package of eight Jaguars during the air raid against the Libyan airbase at Ouadi Doum, on February 16. Two F1CRs also flew pre and post-strike reconnaissance missions.


In October 2007, three Mirage 2000s and three Mirage F1s were deployed at Kandahar Air Force Base, where they flew close air support and tactical reconnaissance missions in support of international forces in Southern Afghanistan.

The Mirage F1 is coming to the end of its useful lifespan within the French Military and the type was retired from service following closures to the 2 main bases Reims-Champagne and Colmar-Meyenheim in 2009-2010.


In July 1973 Dassault tendered the Mirage F1E (Mirage M53) as contender for a new European fighter aircraft contract required by Belgium, Denmark, the Netherlands and Norway. To meet this tender specification the Mirage F1 was equipped with more sophisticated avionics, and the more powerful M53 engine. This engine is shorter than the standard Snecma ATAR 9K50 and required larger air intakes and a shorter rear fuselage. Unfortunately, the F1 was beaten in this potentially lucrative deal by the American General Dynamics F-16. Despite this, the Mirage F1 was an export success : 473 aircraft equipped the Air Forces of South Africa, Spain, Greece, Kuwait, Libya, Morocco, Ecuador, Iraq, Jordan and Qatar.

South African Connection: 
The F1-04 prototype was the first Mirage F1 ever flown by a South African.
Zach Repsold flew it on 6 October 1971. This model differed from the others by using slotted slats. On the 14th March 1974, the French Air Force received their first Mirage F1.

South Africa began looking to replace the Mirage III by the early 1970s . The Mirage F1 was an improvement on the Mirage III: It had an increased speed, increased pursuit flight time , speed (a tripled mach rating) with an increased  ground mission range (doubled) Take off runway use was 1/3 reduced, with 1/4 less approach speed plus increased maneuverability. On the 27th June 1971, Dassault and SNECMA announced a technical cooperation agreement with South Africa for the license manufacture of the Mirage F1 and engine. The intention was to produce up to 100 Mirage F1s.

The 1977 arms embargo against SA invalidated this production license; and the Atlas Mirage F1 Program never moved beyond the assembly stage. The South African Air Force acquired 16 Mirage F1-CZ’s (Serial 200-215) and 32 Mirage F1-AZ’s Serial 216-247).

Mirage F1-CZ '200' was the main project aircraft, whilst Mirage F1-AZ '216' was used as the project aircraft for the 'AZ' fit-out. Due to the approaching Arms Embargo, Dassault rushed the F1-AZ delivery through, leading to teething problems with this ground attack variant.

Delivery from France took place in great secrecy on 4 April 1975 with two Mirage F1-CZ’s transported to South Africa in a SAAF C-130 Hercules. South Africa maintained great secrecy over this aircraft and only revealed a new 'Mirage type' during a fly past at the Ysterplaat Air Show in October 1975. In April 1977 that the press was finally allowed to see the production line in Kempton Park. Even so the existence of the Mirage F1-AZ remained classified until 1980.