Talk:AN/APS-20

Dubious: Goodyear ZPG-3W and Sikorsky HR2S-1W
It is well documented that the 4 Goodyear ZPG-3W blimps used the specially designed and built AN/APS-70 radar (with a massive 42 ft / 12.8 m internal antenna), so the inclusion of the ZPG-3W in this article is extremely dubious. Also, photos of the ZPG-3W show no sign of the AN/APS-20 radome that is so visible on the underside of the ZPG-2W.

Likewise, it is documented that the 2 HR2S-1W helicopters used the AN/APS-32 radar; this is not as strongly documented, but it is obvious from photos of the helicopter that the radome was much larger than that needed for the AN/APS-20, so again this is a dubious inclusion. Not much is known about the AN/APS-32, perhaps it was a development of the AN/APS-20?

Thank you Tfdavisatsnetnet (talk) 15:29, 13 April 2023 (UTC)


 * Why are you assuming that radar arrays only come in one size for a radar type? Many radar arrays are sized for the installation. I've found several sources listing the APS-20E as the radar for the HR2S-1W, with the best one being here. I think the Sikorsky Archive is the anomaly, not the others. BilCat (talk) 20:06, 13 April 2023 (UTC)
 * Well, your "best one" states that the HR2S-1Ws were developed in the 1960s, but the first of these was delivered on 3 June 1957 and the program was terminated after the crash of one of the prototypes on 3 December 1958. The Sikorsky Archive site is run by former Sikorsky employees who had access to Sikorsky documents, so I would think they know their subject, and this gives it more weight. Still, I don't doubt that there was literature published in the 1950s that stated the HR2S-1W was designed to use the APS-20E. The later model EC-121 belly radome and HR2S-1W radome are comparable in size (unlike the early EC-121 versions - it's too bad the EC-121 article doesn't zero in on the introduction of the APS-20E, but the AN/APS-20 article says it was 1953, and that date would fit). I've looked for my Sikorsky books; the best one is MIA, and the next does reference the APS-20E. Let's see what the MIA book says, it may take me a week to get it.
 * But, as as I commented earlier I suspect there is a real possibility that the APS-32 was developed from the APS-20E (and yes, WP bans speculation in articles, but what about Talk pages?). Also, the article entry on the APS-32 is very likely wrong: all of the Grumman TBMs were retired from USN service in the mid-1950s, and the -3W even earlier, so it is highly unlikely that the APS-32 (a mid-1950s development) was intended for the TBM-3W as that article states (and it misnames the TBM-3W as well).
 * I'd vote to leave the dubious flag on the HR2S-1W until hell freezes over, or until we know better what the APS-32 really was. The APS-70 is different: Sky Ships specifically states it was designed for the ZPG-3W, and even includes a cutaway drawing of the huge antenna inside the blimp envelope. It could not have been fitted to any other aircraft. Sky Ships also calls into question the article entry on the APS-70. I'd vote to delete the ZPG-3W from any association with the APS-20.
 * Thanks Tfdavisatsnetnet (talk) 04:09, 14 April 2023 (UTC)


 * The Polmar error could also by a simple typo, and I've seen plenty of very simple mistakes in the SikorkArchives. It's also possible the APS-32 was an upgrade or redesignation of the APS-20E, or even a different model installed later. BilCat (talk) 04:30, 14 April 2023 (UTC)
 * "It's also possible the APS-32 was an upgrade or redesignation of the APS-20E"
 * I think that possibility is very real. Perhaps the APS-32 was the APS-20E with features specifically intended for helicopter operations (i.e. additional vibration dampening). I was too busy to research this in the last few days, and the next 2 don't look good either. But I'll be back. Tfdavisatsnetnet (talk) 22:39, 16 April 2023 (UTC)
 * Hi. In the Radar picket article I changed 'AN/APS-32' to 'AN/APS-20E or AN/APS-32 radar (sources differ)'. Something like that might be appropriate here and in the List of radars article. Tfdavisatsnetnet (talk) 01:35, 18 April 2023 (UTC)