Red Hebe and Bendix AAM-N-10 Eagle missiles

AAM-N-10 adapted radar seeker technology from that of the BOMARC. AN/DPN-53/B I believe. Which, considering the fuselage of the BOMARC (@35″) was wider than the wingspan of the Eagle (@34″, 14″ diameter), was no small achievement. The big deal is likely going to be how the midcourse was handled. If the weapon has an ability to effectively double it’s range using a full on autopilot loft (with a mechanical guidance gyro platform) the weapon will not maneuver but will be capable of decent proportional intercept lead estimation. If it’s simply using a referent signal from the three large secondary apertures on the sides the nose, then it will have a fixed trajectory mechanic (so many seconds at such and such a plane index on the controls, possibly with an altitude input) and the weapon itself will be clumsy in flying a fixed trajectory mechanic without reference to target aspect or range rate changes until such time as the seeker reaches lightoff point downrange which will be conservative and apt to put the weapon right in the teeth of any forward facing jammer emitters.

A man I knew who worked on the program said that what would have made the Eagle great or guffawed (not his word) was the APQ-81 radar. Five foot dish, suspended in an upside down horseshoe frame with backing ‘birdcage’ supports and slung under a concentric hoop structure which spun the ENTIRE unit, rather like AI.IX, through 360`, using the equivalent of a giant washing machine motor on the inside of the radar azimuth traverse race. Elevation adjustment was through independent gimbals halfway down the horseshoe and electrical was through a separate shaft, running up the middle. Cassegrain antenna, FIVE FEET across, with a two element flood horn on the stalk, providing different beam widths which could be interleaved to provide simultaneous RWS/TWS level tracking and display feeds to the primitive analogue FCS computer. Massively powerful, for it’s day. ‘Twice the average as the AWG-9 peak ERPs’ was his description.

If you’ve ever seen the EA-3 which Pt. Mugu maintains with the Air SAR radar to map out realworld, in flight, target signatures, that is the radome which would have housed the APQ-81 for flight testing.

http://1000aircraftphotos.com/Contributions/Visschedijk/Additions/12195L-1.jpg

Assuming that the cheek arrays are CW SARH floods for tethering and that the missile has a fully proportional autopilot for adjusting the parabolic peak of the loft, the weapon will receive SARH modulant range indications from the F6D or the E-1 Tracer and use it’s own nodding seeker cut motions (like on STARM or AIM-54 JAT) to inverse gain track the jammer lobe through a series of gain for depression angle assumptions about range, tipping down at a point where the weapon seeker will go active, presumably high above any FQ jammer coverage (i.e. you have to fly into the sidelobe, through the main and out the back ‘plus some’, before the terminal dive).

If you can do this, within the electronics tech limits (volume, heat, power) of the time, this would effectively allow the weapon to walk up the barrage strobe line with little more than parent rough bearing and own vertical displacement adjustments before stooping down and detonating the W42 at a point where you were sure to prompt out the crew and probably poison any onboard weapons, just by proximity detonation within a 1,200ft blast globe.

Is this ‘good tech’? In comparison with period AIM-7C/D off of Demon or Phantom DLI, I would say so, because the targets the USN were projecting for the mid-60s were Mach 2 weapons carriers with long range supersonic standoff weapons of their own (i.e. Tu-22M with AS-4, replacing Tu-16 with AS-3) and there was simply no way to get up and out and on-speed to put a 15nm ranged weapon into parameters before the game shifted from archers to arrows. Even standing FORCAPs would be hard pressed.

Does Eagle compare well with Red Hebe in this? Dunno enough about the British program or it’s design goals to say. The USN always took their strategic mission a lot more seriously than the ‘Air Defense’ elements of the land based equivalents. Partly because they had the firepower and unpredictability of position to be survivable (you cannot protect a city or even airbase, really) but also because they knew their role as exponents in the nuclear strike mi$$ion funding lines would only remain theirs to own so long as they made it clear they were able to stand and deliver at a time and a certain target set, which the USAF couldn’t reach for hours longer.

IMO, what killed the Eagle was a sea change in the political command and control element which realized that the very intensity with which the nuclear mission was being gamed out could lead to a perception that that was the only club in the bag. This was later proven out by Cuba to an extent but it began earlier not after, with an initial period of drawing the claws back in in England and then Turkey. A process which, in my opinion, -led to- October as the Russians were given a bad signal saw a Pavlovian weakness and tried to test it based on the stimulus-response curve (i.e. we were pulling Thor/Jupiter before the crisis began).

This meant that Eagle and the Missileer were doomed as a function of Kennedy coming into office with a different doctrinal policy vision as much as by virtue of technical shortcomings.

Though the two may well have been tied together as the Eagle without the W42 may not have had the small, agile target, capacity to defeat an inshore MiG threat such as you saw with USS Higbee, where the LRAAM carrier is not in a position as FORCAP to either get the overland kill, in the clutter, or to defend itself and the outer picket/NGS screens without becoming vulnerable to both fast jet evasions, own-side radar lock frat and last-weapon-off-here-they-come! self defense issues.

Truthfully, a carrier’s survivability, inshore, can be measured in hours or at most a few days, something which has been known since the Fleet Exercises of the 20s-30s when we first used them to attack key nodes like the Panama Canal and Pearl. As a blue water system the options (Missile Traps etc.) are far more wide open which only leaves the type of aircraft and their ‘walk to a coast and start swimming’ profile to determine how big a threat the CVBG is before it runs shy of logistics for it’s escort group if nothing else.

If you see the world in colors of A2J, A-3 and A-5, with 1,300nm radii off a single tanking and 1-2 weapons per sortie, the ability to displace from launch points without any fixed targeting association actually limits the needs of the Missileer slow-intercept. If you see Strike as A-4/A-6 with 700nm range-not-radii and a one way trip deployment of single weapons on a diminishing airwing as sortie generation capacity, you have another view entirely and here the Missileer starts to become more necessary as the closer you are to the Bear’s Den, the more apt it is to get a sniff of you and come on the run with whatever they can scramble after a SIOP first exchange theory has put bombers into dispersal to avoid missile strikes.

Having a few jets up, all the time, thus begins to make a lot of sense rather than a couple squadrons of DLI which cannot get out in time to beat the AS-2/3 weapon launch (if radar even sees it).

Again, landwards is different. You can push permanent basing a lot further forward with land based ADGE/DCA in much greater densities but in turn you have to be sure they are only going to come along that axis rather than (for instance) through the GIUK Approaches, because your COG isn’t going to pull up it’s skirts and dash another 100nm in any direction to fool them and thus ALL launches can be from low level using simple coastal photo references and timed routes without any ASST required.

Double Post…

I’m not quite old enough to have had direct experience of 1950s UK missile-development programmes, but I’d question whether these truly constituted ‘engineering archaeology’ compared with their US counterparts. Both nations were having to develop the technology from scratch, so in that respect there was a fairly level playing field. Where the US had the advantage were the size of its budget and the size of its aerospace industry. In the UK, too few engineers were spread over too many programmes and potential programmes.

But I wonder of the class of engineering inside a Firestreak was significantly different to that of a contemporary IR-guided AIM-4B Falcon round.

Electronics technology was moving at a rapid pace in the 1950s, and in some cases during the second half of the decade UK engineers working on a timescale only a few years behind their US counterparts were coming up with better solutions.

I have no information of the potential vulnerability of the Red Hebe to countermeasures, so have no idea how the judgment that it was have been ‘putty’. But I suspect that all radar-guided AIMs of that era had such vulnerabilities. For example, it was not until the AIM-7F (entered service in 1975) that Sparrow abandoned the use of conical scanning.

Despite Bill Gunston (“Blue Boar was doing well in trials so it was cancelled” June,1954) there was always a good reason for abandoning first generation UK GW. Normally because they were never going to work. In Vickers’ case, April,1957, it was in part because GR Edwards had no time for Special Products Div. and under-resourced it. Red Hebe too bulky/heavy, putty for ECM.

UK missiles of the 1950s were, in the immortal phrase once used of the MiG-25, “engineering archaeology” compared to US missiles.

Poorly.