Wednesday 14 February 2018

Supersonic Hun



Historical Background
In early 1949, with the wealth of captured German aerodynamics data, North American Aviation began researching for sustained Mach 1 flight. In January 1951 while its subsonic F-86 fighters were clashing successfully with the MiG-15 over Korea, North American Aviation handed an unsolicited proposal to the USAF for a supersonic day fighter named Sabre 45 because of its 45° wing sweep and being an evolution of the Sabre. The aircraft would be powered by a Pratt & Whitney J57 turbojet which provided the best performance among the early jet engines. In July 1951, the mock-up was inspected and after over a hundred modifications were made, it was accepted as the F-100 on 30 November 1951. In January 1952, the USAF ordered 23 prototypes (YF-100) followed by 23 F-100A models in February and another 250 in August.

Like the F-86, the F-100 has a nose-mounted air intake although thinner and more oval than the original Sabre. The wing of course has more sweep angle than the F-86 and it was also thinner. Decision was also made to move the ailerons inboard, allowing the Super Sabre to have a better rate of roll. Internal armament consists of four Pontiac M39E 20-mm cannons while external ordnance can range from unguided rockets to tactical nuclear weapons. The pre-production YF-100A first flew on 25 May 1953, seven month ahead of schedule, while the first production F-100A was first flown on 9 October of the same year. Test pilots however noted lack of stability at high speeds leading to inertia coupling. Although officially entering service on 17 September 1954 with the 479th Fighter Wing, the USAF declared that it was not ready for large-scale deployment due to deficiencies in the design. By November 1954, there were six major accidents including one on 12 October 1954 which killed North American's chief test pilot, George Welch.

The accidents forced the USAF to ground the entire fleet until February 1955. Because of the still existing problems, the A model was taken out of service beginning in 1958 with the last aircraft leaving active service in 1961. During that time another 47 'A' models were lost to attrition. The F-100A's place was taken by the 'C' model, which was built to satisfy Tactical Air Command's need for a fighter-bomber. The F-100C has longer wings to improve roll but otherwise similar to the F-100A and having all its problems. The inertia coupling was partially solved when the fleet was fitted with yaw and pitch dampers. To allow carriage of weapons and extra fuel, six hardpoints were made available underneath the wings. However not all F-100Cs can carry conventional munitions and like the A model, it suffered from attrition, losing 85 by the time the variant was retired in 1970.

The final single-seat version, the F-100D, became a dedicated ground attack machine with secondary air-to-air fighter capability. Key features of this variant include autopilot, in-flight refueling, ECM equipment and Sidewinder capability. To further address the dangerous flight characteristics, the wing span was extended by 66 cm and the tail area increased by 27%. 65 of the D model were modified to fire the AGM-12 Bullpup missile. As a type, the F-100 received numerous modification programmes during its service life. Many were concerned with the structure, electronics and to improve ease of maintenance. One of them was the replacement of the afterburner can with the one from retired F-102 Delta Daggers.

The F-100 saw combat service during the United States' involvement in Vietnam. Six Super Sabres were deployed to Don Muang air base in Thailand on 16 April 1961, acting as the vanguard for the type's involvement in the conflict until withdrawn in 1971. The Super Sabres mainly acted as fighter-bombers giving close support to ground troops and anti-MiG escort while two-seat F-100F model acted as Forward Air Controllers and performing the first anti-radar, Wild Weasel missions. By the end of their deployment on 31 July 1971, Super Sabres have logged 360,283 combat sorties : just four wings of F-100s have clocked a larger number of combat sorties than their WW2 predecessor, the P-51. Despite being used as escort fighters flying into North Vietnam early in the war, the F-100s recorded no MiG kills, save for one 'probable' on 4 April 1965.  No F-100s were shot down by enemy fighters but 242 were lost through other causes (186 by AA, seven from sapper attcks and 45 in operational incidents).

The F-100 was also used by Turkey, France, Denmark and Taiwan. The last-named received ex-USAF F-100As which were retrofitted with D model vertical tails. A number was lost during reconnaissance missions over China. The Super Sabres of the Armee de l'Air was used during the Algerian War of Independence.

The Kit
The Tamiya kit was released in 2001 following the original Italeri release in 1998. It was originally thought to be a straight re-release of the earlier, 1980s-vintage ESCI kit. Close inspection revealed that while the Italeri kit may indeed a re-release, there are some difference between it and the earlier ESCI kit. as follows:
1. An extra, non-existent frame on the canopy
2. Shorter (275- US gallon) fuel tanks
3. More detailed landing gear parts
4. Raised details for the instrument panel
5. Better-detailed ejection seat(s)
6. External ordnance

The kit engineering is fairly simple but it featured nicely engraved panel lines. Two types of exhaust nozzles were included - standard and the F-102 type. However the air intake is fairly shallow and ended at the cockpit. The decal sheet feature markings for three aircraft - each from USAF, Armee de l'Air and the Danish Air Force.

Construction
As nearly always with aircraft model kits, construction started at the cockpit. Also, as usual I painted the parts while still on the sprue - Gunze Aqueous H317 for the majority of the cockpit and seat, Tamiya XF-1 for the instrument and side panels and  the sidewalls white for the switches and dials. While having more details than the original ESCI kit, they were quite pitiful compared to other kits in the scale. Before joining the fuselage halves together, a ballast of 20 grams was placed at the nose (I just crammed plasticine in the nose halves until it feels 'right'). The wing parts were assembled; no problems here really, but the wing fences were a bit loose in their slots. As the intake trunking was non-existent, the 'bulkhead' was painted black before the intake was cemented to the fuselage. The intake-fuselage joint was not smooth and I had to sand the area for a seamless joint. Another area with bad fit was the lower tray on the fuselage (with two troughs for the two of the cannons) - I still wonder why do they have to make that area separate. As the canopy is a one-piece affair and a couple of decals go on both the canopy and the fuselage, it was attached and masked off. However, like the lower tray mentioned above, the canopy-fuselage fit was not great.

Painting and Decalling
I decided to finish the kit as a Hun from the 353rd TFS, 354th TFW (based at Myrtle Beach, Florida) 1958. Tamiya's instructions have you paint the interior compartment silver but I am of the opinion that they were actually painted US Interior Green. So I made a mix of 2 parts XF-5 Flat Green to one part XF-3 Flat Yellow paint the interior accordingly. The unpainted rear fuselage (on the real aircraft) was painted a mix of Gunze 8 Silver and 61 Burnt Iron while the exhaust was painted straight Burnt Iron. After masking, the rest of the fuselage was painted Tamiya TS-30 Silver Leaf (although with hindsightI think TS-17 Gloss Aluminium would be more appropriate). Afterwards the decals were applied. No problems here as Italeri's in-house decal are pretty good. Inside faces of landing gear bay covers and the airbrake were painted Gunze Silver 8. Tamiya Weathering master 'Soot' was used on the exposed metal area of the fuselage to simulate heat weathering (maybe other shades or colours were more appropriate but that's what I have in my arsenal).The decals were the treated to the usual decal solution application.

Finishing
I forgot to mention that I tried to remove that extra frame on the canopy. While it was removed without a hitch, the clean-up process went awry in the sense that I could not get the canopy clear again - not sure why but I guess my sandpaper were not fine enough (just down to 1500 grit only). Anyway, lesson learnt - try find finer grade of sandpaper and more importantly, do on scrap plastic before committing yourself. As usual, the landing gears were added first to allow the model to stand on its 'feet'. As for 'things under the wings', I decided to substitute the M117 bomb and rocket pods with a pair of AGM-12 Bullpup and a pair of Mk 81 bombs. Both are from Hasegawa weapons sets. The Bullpup has raised mould parting lines while the bombs have a pair of ejector pin marks, all of which needed cleaning up. Flat clear was sprayed onto the bombs while the Bullpups received a semi-gloss coat. Although many photos show USAF Super Sabres have their speed brakes raised while on the ground, I have them lowered for added visual interest. Some paint touch-ups were needed after removing the masks.There was no locating hole on the wing surface for the refuelling probe so I have to cut off the locating tab and just use Mark I Eyeball to place the aforementioned probe.

Conclusion
Although rather old, the Tamiya/Italeri/ESCI F-100 kit is still a good model. The glitches in the kit are rather minor and any reasonably competent modeler can sort them out (and count me out for that). Coupled with a rather low price (I got mine for RM36.00 which I think is half the price of of Hrumpeter's Hun) it was indeed a bargain.

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