F-102 upgrades

[tigercat2]

After researching both the F-102 and F-106, I was wondering if there was ever a plan to upgrade F-102s with the J-75 engine and update the avionics to make sort of a "poor man's" F-106.  Since there were 1000 F-102s built and only 340 F-106s, such an upgrade could have offered more capability at a low cost.


Wes W.

[Captain Canada]

Makes sense to me ! I didn't know the production numbers were that far apart.

[rickshaw]

F-102 and F-106 were basically obsolete by the time they were built and in service.  There are no need for either as interceptors.   There was no serious Soviet bomber threat for either to combat over the North Pole.   What few Soviet bombers did probe US defences could be handled by the aircraft as they were constructed.   So there was no need to upgrade either.    If I was to upgrade one of them, I'd go for the F-106.   It was large enough and had sufficient room in its internal weapons bay to carry bombs there and on it's wing hard points for it to be turned into a useful fighter-bomber.   The F-102 had problems with it's aerodynamics to make it a dangerous aircraft to fly.   It was just supersonic and only then on after burner.   The F-106 was built from the lessons learnt with the F-102.  It was an appreciatively better aircraft.   

[Weaver]

Some F-102s were sent to Vietnam, but achieved a very poor combat record, mainly due to the lack of a gun and problems with the Falcon missile, which was never intended for dogfight work and had an excessively long warm-up time. Had the US been more short of aircraft for that war (say the Phantom was never built, for instance), you might suggest a re-worked 'tactical' F-102, with a gun pack in the centre missile bay, fuel in the outer ones, and Sidewinders on under-wing pylons. The avionics would also need replacing, since the Hughes fire-control system was mainly intended to work with the SAGE air-defence system and data links. You'd probably want to simplify it for 'Nam, with something like the Starfighter or Thuds' NASAAR radar.

Another mod to consider, whether for 'Nam or some other scenario, would be the J-79 engine. Depending on the version (which depends, of course, on the year) it'd provide little to no extra thrust, but it was over 1000lb lighter and had much better fuel consumption. The J-79 would fit in the J-57 'envelope' - Vought proposed it for an advanced lightweight Crusader that was in competition with the F-5E for the MAP order. Whether this is worthwhile depends entirely on the scenario, of course.

Exports might provide another upgrade path. The only real-world F-102 exports were to Greece and Turkey in the 1970s, with no upgrades on offer from the US and no local capability to do their own. Had the aircraft been exported earlier and/or to a more capable customer, they might have asked for US-led upgrades or come up with their own. It was possible to refit each of the F-102's missile bays to carry a single Super-Falcon-size weapon in place of the two earlier versions. Three SARH Super Falcons (or two plus a gun-pack), combined with two or four Sidewinders on new under-wing pylons and upgraded avionics would give you a usefully improved interceptor if you didn't or couldn't trade the aircraft in for F-106s.

Some possible what-if customers:

Canada
Japan
Germany
Belgium
Netherlands
Denmark
Norway
Italy
Spain
Switzerland

Note that the F-102's fire-control system was a highly classified item, so it's unlikely they'd have been exported outside of NATO or other most-favoured allies. Switzerland wasn't in NATO or course, but since they got permission to fit Hughes FCS and Falcons to their Mirages, presumably they could have had them in an F-102 airframe if they wanted them.

The UK and France are off the list because they had their own aircraft industries. However you could imagine an alternate timeline in which they were more 'internationalist' in the 1950s and entered into joint production of the F-102 in the same way that the NATO consortium built the F-104 a decade later.

[scooter]

Note that the F-102's fire-control system was a highly classified item, so it's unlikely they'd have been exported outside of NATO or other most-favoured allies. Switzerland wasn't in NATO or course, but since they got permission to fit Hughes FCS and Falcons to their Mirages, presumably they could have had them in an F-102 airframe if they wanted them.

That's ironic, because the export versions of the 106 would have been backdated to MG-10 SAGE gear instead of the Hughes MA-1 SAGE avionics.

[zenrat]

I built a JASDF Dagger with gunbelly.


http://www.whatifmodellers.com/index.php/topic,41546.0.html

[Weaver]

If the UK had bought into the F-102 program for political reasons, the RAF would have ended up with an under-performing airframe fitted with dubious weapons. Here's an idea for a fairly radical UK-led upgrade programme:

1. British Engine. This would probably have been the case right from the start in order to sweeten the pill for the UK industry and reduce the dollar expenditure, in much the same way as the Spey was fitted to the Phantoms.

2. British Weapons. The RAF was underwhelmed by AIM-4A/B Falcon, so they replace them with Firestreaks. Firestreak needed a missile support pack to provide cooling and electronic interface, so those could go in the missile bays with two or three missiles on external fuselage pylons fitted to the panels that replace the doors. Fitting them on wing pylons would be difficult because the F-102 wing is too thin to take the packs, unlike the Javelin's. It might even be possible to fit a combined MSP for all two/three missiles in one bay and put fuel in the others.

3. Enlarged Fin. This would probably be neccessary to counteract the side-area of the externally carried missiles, in much the same way as it was for the Lightning. The obvious thing to do from a modelling point of view is to fit the F-106 fin.

4. More Power. The F-102 underperformed in speed, climb rate and ceiling, so the RAF updated version has two rocket boosters fitted in the area-rule bulges. From a modelling point of view, this would just mean cutting off the rear point off the bulges and fitting a flat plate with a hole in it. The simplest way to carry the oxidiser would be to put it in the drop tanks instead of fuel, which would also simplify refuelling. If it's a nasty substance like HTP, then tanks could be pre-loaded in a safe room and then wheeled out to the plane and clipped on. If it's a cryogenic like Liquid Oxygen, then the tanks could be kept plugged in to a refrigeration trailer until just before take off. I'm not sure if the real-worls De Havilland Spectre or Armstrong-Siddeley Screamer units would fit in the bulges, but you could easily imagine scaled down versions of both.

A French version would probably have the J-57 since their engine development was behind the US and UK, but otherwise it would be similar, just with SEPR rockets and R-530 AAMs. Since the R-530 was radar-guided and didn't need the cooling pack, they could probably be fitted on the wing pylons, with the rocket oxidiser in the weapons bay instead.

[Mossie]

Part of the reason for discrepancy between the numbers where that a lot of funding was stuck into correcting the F-102A's problems, this pulled funding away from the F-102B (which became the F-106).  For the same reasons, you don't see don't many F-102 projects as it became the F-106.

Early in the F-102B program, it was slated to take the J67, a licence built RR Olympus, which slots nicely into Harold's idea for a British F-102 (or F-106).  There were developmental problems with this engine so when it was canned in favour of the J75.

I've got a book that shows some of the interim designs as things move on from F-102A to F-102B to F-106A.  I'll see if I can dig it out, I'm pretty sure there is a version that shows a variant with a J75 that looks more F-102 than F-106.

[Captain Canada]

Interesting points Weaver thanks for the insight !

[sandiego89]

Besides the NATO and trusted type countries Weaver lists I could also see WHIF scenarios for pushing a dumbed down 102 to other forces, which could have served as a hedge against expanding Soviet clients, or for other forces when you are happy to sell them arms, but not the best of the best, so perhaps expand the list to:

Thailand
taiwan
Middle East, various customers
South/Central America   

[PR19_Kit]

Perhaps the 'dumbed down' versions could do away with the missiles and use a similar belly mounted Vulcan cannon to the F-106 'Six Shooters'?

[Mossie]

I've got a book that shows some of the interim designs as things move on from F-102A to F-102B to F-106A.  I'll see if I can dig it out, I'm pretty sure there is a version that shows a variant with a J75 that looks more F-102 than F-106.

Found it, in Convair Advanced Designs II.  It's a naval variant based on the F-102A, with a tandem cockpit similar to the F-106B and either J67 or J75 engines.  It has upturned wingtips and a clipped tail (like the F-106), but is otherwise very similar to the F-102A.

[KJ_Lesnick]

rickshaw

F-102 and F-106 were basically obsolete by the time they were built and in service.

You mean because of the time-delays due to area-ruling fixes and stuff? 

If I was to upgrade one of them, I'd go for the F-106.   It was large enough and had sufficient room in its internal weapons bay to carry bombs there and on it's wing hard points for it to be turned into a useful fighter-bomber.

I'd agree with that.  Plus, the F-106A was what the F-102 was supposed to be.

The F-102 had problems with it's aerodynamics to make it a dangerous aircraft to fly.

I've never heard anything to suggest that, where did you get that from?


Weaver

Some F-102s were sent to Vietnam, but achieved a very poor combat record, mainly due to the lack of a gun and problems with the Falcon missile, which was never intended for dogfight work and had an excessively long warm-up time.

I thought the cooling-time for the seeker-head was an issue that was related solely to the F-4 (something to do with the amount of cooling and circulation rate in the pylon design)?  Regardless, the rest is largely correct, the AIM-4 lacked a proximity fuse and needed a direct hit.  The AIM-26 was better, and the F-102 could carry 1-2 in the center weapons bay; there were some variants of the F-102 that carried at least a single super-falcon in the outer-bay as well.

Had the US been more short of aircraft for that war (say the Phantom was never built, for instance), you might suggest a re-worked 'tactical' F-102, with a gun pack in the centre missile bay, fuel in the outer ones, and Sidewinders on under-wing pylons.

I would assume that had the F4H been passed over in favor of the F8U-3, the USAF would likely have adopted more F-105's and more F-106's.  From what I remember, McNamara's rationale for selecting the F4H for a USAF fly off was

• It was an effective joint-service aircraft, being that it was already suitable for carrier operations
  
• The F-106A was expensive as hell: $4.7 to $5 million a plane, whereas the F4H was around $1.9 to $2.4 million a pop
  
• The F4H had a comparable top-speed to the F-106 at altitude (Mach 2.6-2.7 vs 2.8 for the F-106); a climb rate that, if not superior in every way, was superior at subsonic/trans-sonic speeds; the interception radius was superior to the F-106 (750 nm vs the F-106's 530-650 depending on drop-tanks); it had superior missiles in the form of the AAM-N-6 (AIM-7C), a radar with a longer engagement envelope (and possible overall range early on).
  
• The F4H/F-110 vs F-106 fly-off would allow him to more easily get his foot in the door, and force the plane on the USAF for other roles, such as the F-105
  
• The F4H was felt to be a better fighter than the F-105 in that it had a higher power to weight ratio, and lighter wing-loading; it could also carry heavier loads than the F-105 (16,700 vs 14,000 lbs), and was possibly capable of a higher top-speed at altitude (2.6-2.7 vs 2.5).
  
• Sure, the F4H couldn't fly as fast at low altitude (probably at all) with payload as the F-105; it wasn't as rugged and had more gust-response either; it lacked the F-106's ECCM equipment, and probably had a less discriminating IRST scanner; the corner velocity being fairly high compared to the F-106 meant it wouldn't turn so good at altitude (mock dogfights proved this, the F-106 almost always won): McNamara might have not realized all of this at the time, but he might very well have been more concerned with cutting costs than finer details (and the devil is always in the details).
  

I doubt they would have bought the F8U-3, though it did have speed (Mach 2.9) and range (same as the F-4B with 1 x 600 gallon centerline, or 2 x 370 gallon drop tanks) on it's side.

The avionics would also need replacing, since the Hughes fire-control system was mainly intended to work with the SAGE air-defence system and data links.

Not really, SAGE was largely used to improve communications functionality (basically, a secure communications system that could not be easily intercepted, or jammed); most of the automation had to do with the fact that the aircraft was a single-seater (a twin-seater has a dedicated radar-operator to compute interception vectors, and launch missiles).

Another mod to consider, whether for 'Nam or some other scenario, would be the J-79 engine.

Yup.

Note that the F-102's fire-control system was a highly classified item, so it's unlikely they'd have been exported outside of NATO or other most-favoured allies. Switzerland wasn't in NATO or course, but since they got permission to fit Hughes FCS and Falcons to their Mirages, presumably they could have had them in an F-102 airframe if they wanted them.

Switzerland is the home of the BIS -- it's a nation that's also a bank.  If you control the bank of the world, you control the world.  They can get anything they want

[rickshaw]

rickshaw

F-102 and F-106 were basically obsolete by the time they were built and in service.

You mean because of the time-delays due to area-ruling fixes and stuff? 

Partly.  Partly because the technology was moving on so quickly.   Bomber streams were perceived initially as the threat.  That then became individual bombers.   Then ICBMs rendered interceptors obsolete.    That occurred in a space of 10 years, barely time for the F-102 to reach service and the F-106 was in development.   The scenario was changing too quickly for them to cope with.

The F-102 had problems with it's aerodynamics to make it a dangerous aircraft to fly.

I've never heard anything to suggest that, where did you get that from?

Comments in various pilot's biographies.  The F-102 was considered dangerous by most of it's pilots.   It had stability problems and wasn't able to perform aerodynamics safely.

[scooter]

F-102 and F-106 were basically obsolete by the time they were built and in service.  There are no need for either as interceptors.   There was no serious Soviet bomber threat for either to combat over the North Pole.   What few Soviet bombers did probe US defences could be handled by the aircraft as they were constructed.   So there was no need to upgrade either.    If I was to upgrade one of them, I'd go for the F-106.   It was large enough and had sufficient room in its internal weapons bay to carry bombs there and on it's wing hard points for it to be turned into a useful fighter-bomber.   The F-102 had problems with it's aerodynamics to make it a dangerous aircraft to fly.   It was just supersonic and only then on after burner.   The F-106 was built from the lessons learnt with the F-102.  It was an appreciatively better aircraft.   

The Six showed that it *was* more upgradable than the Deuce- IFR, gunpack, tests as a Wild Weasel with STARM, additional versions that would have pushed the envelope to Mach 3.  If anything, GD/Convair should have been looking to allow the missile bays to mate newer AAMs, or modify the hardpoints for AIM-9s

When the Mercury 7 complained about not flying, NASA originally gave them Dueces...which then resulted in *more* complaints, and got them Sixes.

And let's not forget that as the USAF was retiring the Century Series in favor of the Teens, the Six continued to soldier on, until the 119th FIS retired their Sixes (as built in 195x) in '88.  No Block numbers, no follow-on alphabet soup.  Just F-106A/B