This is former US Marines Tracker Bu136421, which still has '6421' visible on the fin and 'Marines' on the wings. It was registered to the California Department of Forestry (CDF) as N434DF on 23 Jan 1974, but obviously it was never taken in service and the registration was never applied to the aircraft. Instead it ended up as a spares aircraft for the CDF at Sequoia Field, where it remained until it was moved to the Castle Air Museum on 14 Nov 2012. On 1 Feb 2000 the same registration N434DF was issued to Tracker c/n 335C.

S2F Tracker trials on the Dutch carrier Karel Doorman. Some VS-30 aircraft were embarked for a few days. This one became a Conair Firecat, C-GHNU. Photo from: Nederlands Instituut voor Militaire Historie

Elevated view from the control tower. This is the second Tracker to carry this registration. The first one was c/n 410 (1974-1985), but it never saw active service as such. On 1 Feb 2000 the registration was allocated to the this Tracker.

Elevated view from the control tower. This is the second Tracker to carry this registration. The first one was c/n 656 (1974-1985), but it never saw active service as such. On 1 Feb 2000 it was allocated to the this Tracker.

Elevated view from the control tower. This is the second Tracker to carry this registration. The first one was c/n 656 (1974-1985), but it never saw active service as such. On 1 Feb 2000 it was allocated to the this Tracker.

This Tracker never served as an airtanker, and was never officially registered. It is an S2F-1, ex BuA136745, which was delivered to the Japanese Navy on 12 Mar 1959 as 4146. In Oct 1983 it was acquired by Hemet Valley Flying Service as a spares aircraft and stored at at the Hemet-Ryan airtanker base. In 2001 it was restored and placed on display as a memorial. The text on the memorial plaque reads: "Dedicated in memory of Lloyd M. Venable - A pioneer in the aviation industry - Founder of Hemet Valley Flying Service - 1946. Born Oct 3, 1906 - Died Feb 1, 1991."

Now with the Cactus Air Force Wings and Wheels Museum at Carson City, Nevada.

Third Tracker to carry this registration. First one was c/n 052 (1974-1984), and the second one was c/n 445 (1986-2002). This third one, a Turbo Tracker, took it up on 9 Oct 2003.

Third Tracker to carry this registration. First one was c/n 052 (1974-1984), and the second one was c/n 445 (1986-2002). This third one, a Turbo Tracker, took it up on 9 Oct 2003.

Turbo Firecat just starting its demonstration drop. Ex US Navy 136552, withdrawn from use in 1980 and stored. To N4477Z in 1984 and to C-GQCW with Conair the same year. Converted by them to Firecat airtanker and delivered to the Sécurité Civile in June 1985 as F-ZBEX/9 (using F-WDSX as ferry reg). To F-WEOL in Sep 1995 and flown to Conair in Canada. Stored at Abbotsford awaiting conversion to Turbo Firecat. Became C-GFZG in May 2000 for testing and re-delivered as Turbo Firecat F-ZBMA/24 in Jun 2002 (again using F-WEOL as ferry reg).

On display at Parco Tematico dell'Aviazione near Rimini.

ex US Navy 149875, previous serial AS-0105. Preserved as a gate guardian at Comando de la Aviación Naval, Puerto Cabello

BuNo 149865

These are inaccurate markings on this museum display. The aircraft was indeed operated at NAS Pax with the Naval Research Laboratory's (NRL) air component. In 2004 the NRL air component was formally designated a squadron, Scientific Development Squadron One VXS-1. It was given a tail code and squadron patch. Squadron's and units aboard NAS Patuxent River used to be charged with maintaining the upkeep of the Pax museum aircraft, and when the S-2D was brought in for a fresh paint job, someone decided to mark the bird up in VXS-1 markings instead of maintaining the aircraft's actual markings from it's time in service with NRL.