F-24 through F-34

[convairxf92]

Anyone out there know what happened in between the YF-23 and the XF-35? I've been told that because by a friend of my Dad's who works at Lockheed/Grumman that the military kept the "35" because it crossed over easily from the X-35, rather than call it the F-24. Is there any truth to that or were there experimental aircraft that the general public has not been privy to. Thanks.

 

[quellish]

Anyone out there know what happened in between the YF-23 and the XF-35? I've been told that because by a friend of my Dad's who works at Lockheed/Grumman that the military kept the "35" because it crossed over easily from the X-35, rather than call it the F-24. Is there any truth to that or were there experimental aircraft that the general public has not been privy to. Thanks.

There were, certainly, but none carried X-plane designations. If they had DoD designations at all they were in the Y-series, like the YF-113G.
You can read more about how X-designations are allocated here:
http://www.thexhunters.com/xplanes/index.html

Most of these programs though only had program names or project numbers rather than official designations.

 

[TomS]

There was no XF-35. The LM JSF demonstrator was X-35; all of the production aircraft are F-35s (no XFs or YFs). It was unprecedented for the fly-off aircraft to use X-series designations instead of XF or YF.

When the contract announcement was made, a reporter asked the new plane's designation and MGEN Mike Hough, the project manager, said "F-35," which was pretty clearly a mistake on his part. Even Lock-Mart was taken aback; for a day or so, their web pages said F-24. But rather than admit that the general had misspoken, they overrode the nomenclature office and left a gaping hole in the numbering system.

 

[aim9xray]

It turns out that the press conference transcript is still on DefenseLink (http://www.defenselink.mil/transcripts/transcript.aspx?transcriptid=2186). So here goes....

Q: Could I ask Lord Bach what the position of the U.K. is on choosing between the CV [compatible variant for carrier landing] version and the STOVL version? And secondly, what will be the value of the U.K. contribution to the SDD phase?

Bach: Yes. A pleasure to answer you. The two STOVL designs that were put up are very different ones. And after today's decision, we're in a position to examine the preferred design and all its implications. And in due course, we will make our -- will make our decision.

Your second question, I think, related to what we were putting in to the system development demonstration, the SDD stage, the one we're about to reach. It's 2 billion pounds. And --

Roche: It's dollars. Dollars. (Laughter.)

Bach: Forgive me. (Laughter.)

Roche: Thank you. We thank you very much. (Laughter.)

Bach: May I start that again? (Laughter.) Two billion dollars. And as far as spending of the United Kingdom itself is concerned, $840 million.

Q: Mr. Aldridge?

Aldridge: Yes, right here.

Q: What's going to be the nomenclature for these airplanes? What's the designation?

Aldridge: Very good question. It's going to be called -- the Lockheed version was the X-35 --

MR.: Mike knows. Mike knows the answer.

Mike, the answer is?

Hough: F-35.

Aldridge: F-35. Thank you, I knew -- X-35 was the Lockheed --

Q: How did you decide on that? Where does that come from, the F-35?

Hough: It's a list of the different variants, different companies, different --

Aldridge: The Boeing version was X-32.

Okay.

Q: Can you give us an idea of what you consider the unit costs to be at this point, what you anticipate them being for each version?

Aldridge: The unit cost -- it varies with each variant. The STOVL version is more expensive than the carrier version. And the number I remember -- and, Jim, you might be able to help me -- I remember a number, but I'm not sure it's right.

So there you have it. I recall listening to the conference live on the radio and shaking my head as I heard this in realtime.

The ever excellent designation-systems.net also has additional backstory at: http://designation-systems.net/usmilav/nonstandard-mds.html#_MDS_F35

 

[TomS]

Thanks for that. I had a link, but it was dead and I wasn't able to find a working one.

I had much the same reaction you did -- I remember being amazed that they hadn't anticipated such an obvious question in the briefing.

 

[Skybolt]

Sometime I think that officials do that just to make the future aviation historians puzzling and going mad trying and plug the holes in the sequence. Like F-117, SR-71, F-20 and so on.

 

[LowObservable]

The X-designators for the JSF demo program were a legacy from the original DARPA CALF project, which definitely was experimental. CALF was originally assigned X-32 - two examples of one design were to be built, one in CTOL configuration (X-32A) and the other in STOVL form (X-32B). By the time that it became JSF, with competing demonstrators, X-33 and X-34 had been assigned, so the second JSF CDA became X-35.

Interestingly, the JSF program office site has this explanation (http://www.jsf.mil/contact/con_faqs.htm):

Why is the Joint Strike Fighter (JSF) known as the F-35 instead of F-24?
During the announcement of the winner of the JSF competition, then program manager, LtGen Mike Hough, USMC stated that the aircraft family would be known as the F-35. This was not a mistake. Following the announcement, a formal Mission Designator System (MDS) request was made and approved by the Department of the Air Force.

This is of course a load of dingo's kidneys, as Andreas' excellent site makes clear.

 

[frank]

IIRC correctly, F-117 was designated as such for security reasons, like the U-2 being included in the Utility category, SR-71 was a mistake by President Johnson (supposed to be RS-71) & rather than correct the President, similar to the X-35 screw-up, they changed the designation. F-20 is no secret, however, F-19 is a hole.

Sometime I think that officials do that just to make the future aviation historians puzzling and going mad trying and plug the holes in the sequence. Like F-117, SR-71, F-20 and so on.

 

[TomS]

The link to Andreas' site, given above, gives explanations of these.

The origin of F-117 is unclear; it may be security, but it may simply be administrative.

SR-71 was a deliberate change in the announcement Johnson was given to read, not an error by him.

 

[Just call me Ray]

To fill in one of the gaps, this is the would-be F-32 (as in, if Boeing had won it would've been called the F-32 much like how the X-35 became the F-35):

 

[quellish]

The origin of F-117 is unclear; it may be security, but it may simply be administrative.

If you ask the right people there is a good story behind "F-117". The simple answer though is that at the time the aircraft was becoming operational they were shacked up next to the Red Eagles program at TTR. The Red Eagles had been using TTR for a few years, but the SENIOR TREND program brought an influx of funds to the base. While the SENIOR TREND pilots were writing their logbooks they had to put *something* and followed the lead of their "roommates" and used F-117 much as the Red Eagles used F-113, etc. Later this continued when writing flight manuals, etc. and eventually became official.
To some extent this practice continues today.

 

[OM]

...And for those unfamiliar with the Red Eagles:

http://www.powells.com/biblio?isbn=9781846033780

 

[convairxf92]

One possible gap solved - the A-24 Dauntless was redesignated the F-24 in 1948 when the USAF was formed. A similar thing happened to the A-26 Invader, which was redesignated the B-26. http://www.uswarplanes.net/dauntless.html

 

[Robert]

One possible gap solved - the A-24 Dauntless was redesignated the F-24 in 1948 when the USAF was formed. A similar thing happened to the A-26 Invader, which was redesignated the B-26. http://www.uswarplanes.net/dauntless.html

...and pursuit (P) aircraft were re-designated as fighters (F) at the same time.

 

[crusader97]

There's one theory that a YF-24 existed already. No one is really sure if it was a derivative of an existing or cancelled project (A-12, YF-23, very stealthy F-15) but it's existence was and is still classified. Going with the traditional numbering systems, the X-35 should have been designated the F-25 - and this would have raised a lot of eyebrows as to why F-24 was skipped. Like I said, this is one theory, but the biography of the former commander of the classified test squadron includes (or did at one point) YF-24 under the list of aircraft that he had piloted.

 

[aim9xray]

FWIW, they also "gapped" the engine designation system for JSF; jumping from the F129 (in the RQ-3) directly to the F135. (which leads to the sentence: The F135 engine is installed in the F-35 aircraft which was preceded by the X-35 testbed/prototype....)

 

[frank]

Considering that F-24 was well before the re-numbering in the early '60s, that's not the gap in question.

One possible gap solved - the A-24 Dauntless was redesignated the F-24 in 1948 when the USAF was formed. A similar thing happened to the A-26 Invader, which was redesignated the B-26. http://www.uswarplanes.net/dauntless.html

 

[Andreas Parsch]

There's one theory that a YF-24 existed already. No one is really sure if it was a derivative of an existing or cancelled project (A-12, YF-23, very stealthy F-15) but it's existence was and is still classified. Going with the traditional numbering systems, the X-35 should have been designated the F-25 - and this would have raised a lot of eyebrows as to why F-24 was skipped. Like I said, this is one theory, but the biography of the former commander of the classified test squadron includes (or did at one point) YF-24 under the list of aircraft that he had piloted.

First, a relevant source for the story:
http://web.archive.org/web/20050318164828/http://www.edwards.af.mil/units/bio/lanni-bio.html

The web page was hosted by edwards.af.mil in 2005, and showed the "YF-24" entry. While it has been long since removed (and is therefore only available in the "Internet Archive" of web.archive.org), I've seen the "original" page at the time. So it's no fake or hoax.

Second, my own opinion : Because the use of "YF-24" for a classified aircraft is apparently proven, the idea that the F-35 "mistake" was a deliberate one isn't so far-fetched at all. Designating the JSF as F-24 would have confused everyone cleared on the secret YF-24, and designating it as F-25 would have given the YF-24 much more attention than the USAF could like.

Regards
Andreas

 

[overscan (PaulMM)]

In my opinion, it is unlikely that an AF pilot would be the first to fly a US prototype, it would be a manufacturer test pilot. So either the statement is inaccurate, and he meant first AF flights of two classified prototypes, or we are actually talking about first flights of Russian aircraft, e.g. MiG-29, Su-27 etc. Personally I think the second is more likely.

Regardless, there is nothing there that connects the YF-24 designation to a prototype - its simply listed as something he's flown, not connected necessarily to the classified prototypes mentioned elsewhere. I think its more likely YF-24 is the cover designation for the MiG-29 or Su-27. Or a typo.

 

[Hammer Birchgrove]

IIRC correctly, F-117 was designated as such for security reasons, like the U-2 being included in the Utility category, SR-71 was a mistake by President Johnson (supposed to be RS-71) & rather than correct the President, similar to the X-35 screw-up, they changed the designation. F-20 is no secret, however, F-19 is a hole.

Sometime I think that officials do that just to make the future aviation historians puzzling and going mad trying and plug the holes in the sequence. Like F-117, SR-71, F-20 and so on.

According to Wikipedia, it wasn't Johnson's fault he said the wrong letters, it was a miss-print in the paper he had been given.

 

[Just call me Ray]

In my opinion, to call a plane the "F-35" to hide the existence of the "YF-24" only to have the existence of the "YF-24" published on the Internet seems mightily stupid, so I don't buy it.

 

[TomS]

According to Wikipedia, it wasn't Johnson's fault he said the wrong letters, it was a miss-print in the paper he had been given.

Wikipedia is wrong, as is often the case is specialized fields. Andreas' description at Designation Systems.net is correct. The change from RS to SR was a deliberate change by Curtis LeMay, not a mistake.

http://www.designation-systems.net/usmilav/nonstandard-mds.html#_MDS_SR71

 

[OM]

Wikipedia is wrong, as is often the case is specialized fields.

...Actually, I've found the specialized topics and science-based articles are far more reliable in terms of accuracy than the genre-based ones. Those dedicated to TV shows and fan-centric topics tend to be total shite because three or four sexless basement-dwelling schoolboys - usually from Englandland - have used hoze accounts to vote themselves into admin status, and abuse their ill-gotten powers to keep articles with lack of real information unless its something they deem "important". That's why I'll trust an article about a simple hex-headed bolt before I'll trust an article about Lost.

 

[Andreas Parsch]

In my opinion, to call a plane the "F-35" to hide the existence of the "YF-24" only to have the existence of the "YF-24" published on the Internet seems mightily stupid.

Sure. But so is publishing "YF-24" in the first place. That something is "mightily stupid" is apparently not completely sufficient not to do it ;D! Anyway, I still think the "simple" explanation (spontaneous mistake, when the JSF winner was announced) is the most likely. All I wanted to say is that the alternative is not totally implausible.