Prototype Designations

There are significant discrepancies in published information about the prototypes for the Thunderstreak and Thunderflash aircraft. Congress, the military, Republic, and aviation in general, were dealing with several issues. These included politics, interagency powers, company finances, engineering and aerodynamics progress, and the Korean war. Consequently, several military aviation companies were subjected to a variety of decisions affecting military aircraft designations. Republic and the F-84 were not immune. Therefore, experimental and service test aircraft in the F-84 program received designations, redesignations, and more redesignations, due to political decisions and engineering and aerodynamic advances. This list is an effort to identify what aircraft received particular designations, so we can all agree upon which particular aircraft we are talking about. The aircraft are listed in the order created.

Serial Number 49-2430
Initially designated YF-84F (the so-called "first" YF-84F), later redesignated YF-96A, and redesignated YF-84F (again), served as the first prototype for the F-84F Thundjerstreak. Then, modifed for the FICON program feasability testing and redesignated YRF-84K (or, some sources state, YRF-84F or YRF-841K). Now displayed at the Air Force Museum in Dayton, Ohio, in its YRF-84K configuration, although the Museum has it designated as YRF-84F, which, in my opinion leads to confusion with YRF-84F serial number 51-1828; see below.

I have listed this aircraft in its first iteration as YF-96A Thunderstreak First Prototype,
and in its second iteration as YRF-84K FICON Test.

Serial Number 51-1344
This is the so-called "second" YF-84F. Served as the second prototype for the F-84F Thunderstreak.

I have listed this aircraft as YF-84F Thunderstreak Second Prototype. Further confusing the matter of the YF-84F/YF-94A prototypes, a photograph of 51-1344 shows it falsely designated as 49-2430. See photo below.

Why would the plane be falsely designated? I don't know the answer, but my hunch is as follows. At some point, Republic needed photos of the first prototype, 49-2430, but the aircraft was not available (perhaps either due to the FICON program or other modifications which may have been made to the aircraft). So, as 51-1344, the second prototype, which, having the deepened fuselage as the major external difference, was similar in appearance to 49-2430, was painted with the false serial numbers for a photo session, then changed back to the correct numbers 51-1344/FS-344B afterward. If this is so, it would not be an isolated occurence of misidentification by Republic of F-84 aircraft, as a photo of the YF-96A was widely distribubuted -- in fact was used by Republic on a company poster -- as being of an "F-84F Thunderjet." This photo is at top of page 22 in McLaren's book, and is shown below as it appeared on the Republic poster. Although the two aircraft have many features in common, they are also easily identified because the YF-96A 49-2430 has a round intake and F-84E fuselage, and the YF-84F has an oval intake with deepened fuselage.

Serial Number 51-1345
This is the so-called "third" YF-84F. Served as the first prototype for the RF-84F Thunderflash.

I have listed this aircraft as YF-84F Thunderflash First Prototype.

Serial Number 51-1828
YRF-84F. Served as the second prototype for the RF-84F Thunderflash. The YRF-84K (serial number 49-2430) is often referenced as YRF-84F, which, in my opinion is (a) incorrect based on the documentation I have seen, and (b) certainly leads to confusion with this aircraft as to which of the two aircraft is being referenced.

I have listed this aircraft as YRF-84F Thunderflash Second Prototype.

Go to page about this photo YF-96A on Republic poster YF-84F SN 51-1344
YF-96A 49-2430. Note that intake is round. Photo courtesy of E.J. Boss.
YF-96A 49-2430 on Republic poster. Poster courtesy of Michael Bradley.
YF-84F 51-1344 falsely designated as 49-2430. Note that intake is oval. Photo courtesy of Raymond L. Puffer.

These photos are not linked to pages with large images. See the respective F-84 series, or the contributors' photo pages, for the pages with large images.

Contents Copyright Bruce Craig -- All Rights Reserved