Vought XF8U-3 Crusader III

[shockonlip]

And don't forget Airpower 1977 (Cover and awesome photo from attached).

Anybody know of where I can get
a nice large online image of the second photo
below?

Thanks!

Merry Christmas!

I LOVE this shot!!

It's like just sitting there waiting for me to climb into it !!

Thanks again TT !!

 

[Tailspin Turtle]

Planned first flight for #3 was 5 October 1958. Have yet to find confirmation that did take place.

bill
[/quote]

In February 1957, the first XF8U-3 was scheduled to fly on 13 June 1958 and actually beat that by a few days. The second was to fly on 29 August and actually flew on 27 September at Vought, being ferried to Edwards on its third flight. As you noted, the third airplane was to fly on 5 October. I don't know why the second airplane was almost a month late after the first one was a bit early, but the usual reason is to incorporate changes from initial flight test of the first one. It's impossible to establish a trend from that but it seems likely that the pressure and priority would be on flying the second airplane and getting it to Edwards for the fly off. The almost inevitable shortage of a few parts would result in the delay of the completion of the third airplane. It was also the first airplane with a missile control system and the first of anything results in a risk of schedule problems with completion and checkout.

27 December update: According to a photo date analysis found in the files at Vought, the extant photos of the third airplane were probably taken between 25 November and 3 December, with the photos probably being taken of the takeoff for the "probable ferry to Edwards AFB." I'm still looking for a credible record of the first flight date.

 

[sferrin]

 

[Tailspin Turtle]

Thanks,

Hadn't thought to check youtube...

T

 

[sferrin]

The guy who posted that clip seems to have access to some of the rare stuff. It might not hurt to drop him an email.

 

[Abraham Gubler]

Wow the XF8U-III even sounds good...

 

[overscan (PaulMM)]

Access

The archival holdings of the NASA Ames History Office are open to the public. The office does
not collect sensitive, classified or otherwise restricted records for its collections, so anyone may
visit the archive and access the unrestricted records contained therein. Because the office is
located on a secured federal facility, patrons are asked to provide notice in advance of their
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be required to fill in a security form. If you are a Foreign National, plan to provide ample notice
before your research visit, as the process for securing authorization to enter the facility can take
up to several months.

National Archives and Records Administration

As the official repository for U.S. Government records, the National Archives and Records
Administration (NARA) holds the largest collection of Ames records. The Pacific Region facility
in San Bruno, California houses hundreds of boxes of documents generated at Ames, spanning
from 1939 to roughly 1971. NARA's Pacific Region facility in Laguna Niguel, California and main
research facility in College Park, Maryland ("Archives II") also hold documents pertaining to
Ames. The most complete Ames records at NARA deal with Ames prior to the formation of
NASA, and are a treasure trove of material on aeronautical research and wind tunnel
construction in the 1940s and 1950s. For access, researchers must contact NARA directly,
though they should first consult finding aids developed by the NASA Ames History Office, which
are accessible through the Online Archive of California portion of the California Digital Library
(see Online Archive of California, below).

http://www.archives.gov/pacific/archives/san-francisco/contacts.html

Series 31. Central Files, 1944-1966. [9SS-255-93-17][255-70E-1261] . 53 cu ft.

[ Box 39 ]
FO-3 . AIRPLANES - F8U--3 . 1961
[ Box 39 ]
FO-3 . AIRPLANES - F8U-3 . 1960
[ Box 39 ]
FO-3 . AIRPLANES - F8U-3 . 1959

sanbruno.archives@nara.gov

Contacts for Questions about NASA Ames History

Please direct to the NASA Ames Archivist any general reference questions, queries about donating personal papers or memorabilia to the NASA Ames History Office, or any questions not covered here.

history@mail.arc.nasa.gov | (650) 604-1032

Looks like a start?

Also, Mike Machat's done a nice F8U-3 painting. Might be nice for cover, or to have in the book?

http://www.brooksart.com/Supercrusader.html

 

[overscan (PaulMM)]

On Saturday morning, 24 October 1959, a little more than a year after the metamorphosis of the NACA into NASA, approximately 20,000 visitors marched through the gates of Langley Field to attend a public open house that was being held in conjunction with NASA's First Anniversary Inspection. The NACA's first anniversary had passed unnoticed; NASA's proved to be a controlled mob scene. 1

The crowds came at NASA's invitation. Local newspapers and community groups had spread the word: for the first time in its 42-year history, Langley Research Center was admitting curious outsiders into the previously sheltered sanctuary of aeronautical research. NASA scientists, engineers, and technicians would show the public just what the new space agency had been doing to launch their country into space. Throughout the day, men, women, and children streamed through the huge NASA aircraft hangar as well as through two other large buildings full of exhibits that represented a cross section of NASA programs. Escorting the visitors was a handpicked group of articulate and polite NASA employees whose job was to handle the pedestrian traffic, guide the visitors through the buildings included in the program, and explain the exhibits.

The visitors moved "in fascination" past the many marvels on display.2 They saw helicopters and aircraft, including a Chance Vought F8U-3 navy supersonic jet fighter used by NASA for sonic-boom research over Wallops Island

http://history.nasa.gov/SP-4308/ch2.htm

 

[overscan (PaulMM)]

Oh, and don't forget the F9U Super Crusader drawing here. Pretty sure its bogus

http://www.secretprojects.co.uk/forum/index.php/topic,1013.msg8142.html#msg8142

 

[Tailspin Turtle]

Also, Mike Machat's done a nice F8U-3 painting. Might be nice for cover, or to have in the book?

http://www.brooksart.com/Supercrusader.html

Thanks for the thought. Mike's my editor for Specialty Press on the fighter book and he has already sent me a low res copy of that picture.

 

[Tailspin Turtle]

Series 31. Central Files, 1944-1966. [9SS-255-93-17][255-70E-1261] . 53 cu ft.

[ Box 39 ]
FO-3 . AIRPLANES - F8U--3 . 1961
[ Box 39 ]
FO-3 . AIRPLANES - F8U-3 . 1960
[ Box 39 ]
FO-3 . AIRPLANES - F8U-3 . 1959

sanbruno.archives@nara.gov

Contacts for Questions about NASA Ames History

Please direct to the NASA Ames Archivist any general reference questions, queries about donating personal papers or memorabilia to the NASA Ames History Office, or any questions not covered here.

history@mail.arc.nasa.gov | (650) 604-1032

Looks like a start?

Much appreciated - this was on my list of things to do but you've provided a better synopsis on where these are and how to contact them than I had...

 

[shockonlip]

That XF8U-3 video clip was part of a TV program that aired here in the US.

I remember seeing it.

Give me awhile and I'll remember the name, unless someone else remembers it first.

 

[shockonlip]

I now recall.

The XF8U-3 sequence on YouTube that was posted here, was part of a
program in the Discovery Wings Channel.

The episode was part of the "Sea Wings" series and specifically in the
episode entitled: "Last Of The Gunfighters", on the F-8 Crusader.

It is around 40 minutes into the episode (from what I recall).

Also as spectacular as the sequence you saw is, it is not the entire
sequence! There is about 1/3 to 1/2 of it missing on YouTube!

The sequence begins with an awesome shot of the XF8U-3 being pulled
out of a hangar. What looks like the XF8U-1 prototype is parked nearby,
and the sequence actually begins on it, from what I recall.

The XF8U-3 then is pulled out of the hangar, rolls by, and then there is
a sequence where it taxis by under its own power. Then the takeoff/flight
sequence that you all saw on the YouTube sequence posted.

So I would suggest looking into the Discovery Wings Channel - Sea Wings
episode I mentioned above. And it may even be for sale somewhere on
the Net, or eBay or something.

 

[KJ_Lesnick]

Was the F8U-3 as maneuverable as he earlier F8U-1 or -2's?


KJ

 

[Abraham Gubler]

I now recall.

The XF8U-3 sequence on YouTube that was posted here, was part of a
program in the Discovery Wings Channel.

The episode was part of the "Sea Wings" series and specifically in the
episode entitled: "Last Of The Gunfighters", on the F-8 Crusader.

Do you recall who the person was talking about the XF8U-III's dogfighting ability?

 

[sferrin]

I now recall.

The XF8U-3 sequence on YouTube that was posted here, was part of a
program in the Discovery Wings Channel.

The episode was part of the "Sea Wings" series and specifically in the
episode entitled: "Last Of The Gunfighters", on the F-8 Crusader.

Do you recall who the person was talking about the XF8U-III's dogfighting ability?

He was one of the test pilots. I don't recall which one but the same comments (probably from the same interview) are in the issue of Classic Wings that covered the XF8U-3. Don't have it handy though or I'd get the name for you.

 

[shockonlip]

Was the F8U-3 as maneuverable as he earlier F8U-1 or -2's?


KJ

The III was around 3500 lbs heavier than the F8U-1 (20,000 lbs dry vs 16,500 dry),
due to it's 3 ft longer wing span, 30 pct greater wing area, and 4 ft longer fuselage,
and other equipment)). But it had a J75 with 25,000 lbs thrust (in burner) vs the
F8U-1's 18,000 lbs thrust (in burner) (the prototype XF8U-3 had 29,000 lbf in burner).
The thrust to weight is reported by some to be around .62 for the F8U-1/2 to .77
for an XF8U-3 with 32,320 lbs of fuel and a J75 with 25,000 lbf in burner.

So the thrust to weight advantage of the III would give it some definite
advantages, and given the glowing praise for the XF8U-3 from its pilots in almost every
piece about it, I wouldn't be surprised that the answer to your question is yes.

There is much praise for it spread throughout the "Wings Of Fame" piece quoted at the
beginning of this thread, from the pilots on the Navy Preliminary Evaluation (NPE) Team
that were assigned to test it.

Also in the book: "Mig Master", by Barrett Tillman, Naval Institute Press, 1980, 1990 (I
have the second edition), two Vought test pilots: John Konrad (chief test pilot) and
Bob Rostine, are reported to have said: "John Konrad and Bob Rostine, both considered
it the finest aircraft they had ever flown."

And I digress about the III vs the Phantom: there are those amusing stories, when
after the F4H won the flyoff, and the XF8U-3s went to NASA, that NASA pilots flying
out of Langley, Virginia in their new XF8U-3s, gleefuly bounced Phantoms undergoing
evaluation at Patuxent River. The Navy test pilots reportedly complained, and the sport
ceased."

I digress some more: The F8U-1 itself was also used as a test vehicle for XF8U-3
technology. In "Mig Master" there is mention of a March, 1958 event where
Bob Rostine got into trouble in an dash-one during landing while testing an
experimental leading edge for the XF8U-3.

But getting back on your question: Former F-8 pilot and retired Rear Admiral Paul Gillcrist,
in his excellent magazine piece: "Crusader vs Phantom"; Flight Journal, December, 1997,
indcates that after 12 years as a Crusader pilot, and 167 combat missions in the F-8 in
Southeast Asia, that the "the F8U-3 design corrected so many of the horrible features
of the F8U-1 and -2 that any Crusader pilot's mouth would have to water at the thought
of taking the big airplane into combat over North Vietnam."

By the way, Rear Admiral Gillcrist was somewhat involved in the XF8U-3, as he was in
Navy Test Pilot School at the time of the flyoff, and took part in some of the briefings
at Vought and McDonnell. He also indicates that the XF8U-3 was only 2000 lbs heavier
(empty) than the F8E, instead of 3500lbs, as I stated above.

He also indicates that the design team at Vought had done a preliminary design on
a variation the the F8U-3, which had a H2O2 powered rocket engine as a booster
to permit a short term 80,000 ft intercept capability !!

I also suggest: Air Classic, Nov. 1977: "Crusader! History of the Navy's Supersonic Fighter".

 

[shockonlip]

I now recall.

The XF8U-3 sequence on YouTube that was posted here, was part of a
program in the Discovery Wings Channel.

The episode was part of the "Sea Wings" series and specifically in the
episode entitled: "Last Of The Gunfighters", on the F-8 Crusader.

Do you recall who the person was talking about the XF8U-III's dogfighting ability?

Yes, it was the famous John Konrad, former chief test pilot of Vought and the guy
who flew the first flights on alomst all of the F8U series.

 

[sferrin]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

 

[Tailspin Turtle]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

That's one of a handful of errors and misstatements about the F8U-3 that have been repeated in articles and on line. Both the first and second XF8U-3 first flew with the J75-P-5N engine that was rated at 24,500 lbs of thrust. After 30 flights, give or take, both were retrofitted with the YJ-75-P-6 rated at 26,000 lbs of thrust. There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. The only production F8U-3 to fly was powered by a J75-P-5N due to engine availability but the production engine was to be the P-6.

 

[sferrin]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

That's one of a handful of errors and misstatements about the F8U-3 that have been repeated in articles and on line. Both the first and second XF8U-3 first flew with the J75-P-5N engine that was rated at 24,500 lbs of thrust. After 30 flights, give or take, both were retrofitted with the YJ-75-P-6 rated at 26,000 lbs of thrust. There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. My guess is that the only production F8U-3 to fly was powered by a P-6.

That makes more sense. So. . .do you have any info on the one they were thinking of fitting with a J-58? As I understand it it wouldn't have been in the familiar configuration that is used for the Blackbird (with the bypass ducts) but more of a conventional type of lower power.

 

[KJ_Lesnick]

Shockonlip,

Former F-8 pilot and retired Rear Admiral Paul Gillcrist,
in his excellent magazine piece: "Crusader vs Phantom"; Flight Journal, December, 1997,
indcates that after 12 years as a Crusader pilot, and 167 combat missions in the F-8 in
Southeast Asia, that the "the F8U-3 design corrected so many of the horrible features
of the F8U-1 and -2 that any Crusader pilot's mouth would have to water at the thought
of taking the big airplane into combat over North Vietnam."

(Bold Emphasis mine)

What horrible features did the F8U-1 and F8U-2 possess? From what I remember hearing it was an amazing dogfighter...


KJ Lesnick

 

[Tailspin Turtle]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

That's one of a handful of errors and misstatements about the F8U-3 that have been repeated in articles and on line. Both the first and second XF8U-3 first flew with the J75-P-5N engine that was rated at 24,500 lbs of thrust. After 30 flights, give or take, both were retrofitted with the YJ-75-P-6 rated at 26,000 lbs of thrust. There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. My guess is that the only production F8U-3 to fly was powered by a P-6.

That makes more sense. So. . .do you have any info on the one they were thinking of fitting with a J-58? As I understand it it wouldn't have been in the familiar configuration that is used for the Blackbird (with the bypass ducts) but more of a conventional type of lower power.

I'm a little hazy on the Navy's J58. It appears to have been intended to allow unlimited operation in afterburner so the F8U-3 and supposedly the A3J could fly at Mach 3. From what I've found so far, the Navy's J58 didn't have a much higher rating than the J75. I'm not sure whether the improvement was to be in SFC or in temperature tolerance. "Unlimited" time in AB doesn't mean much you burn all your fuel less reserve in 10 minutes. In any event, according to this report it turned out to have fundamental flow issues which were solved with a compressor bleed bypass in time to provide an engine for the Lockheed program: http://www.bobabernethy.com/pdfs/Never%20Told%20Tales%20of%20P&W3.pdf

 

[shockonlip]

Shockonlip,

Former F-8 pilot and retired Rear Admiral Paul Gillcrist,
in his excellent magazine piece: "Crusader vs Phantom"; Flight Journal, December, 1997,
indcates that after 12 years as a Crusader pilot, and 167 combat missions in the F-8 in
Southeast Asia, that the "the F8U-3 design corrected so many of the horrible features
of the F8U-1 and -2 that any Crusader pilot's mouth would have to water at the thought
of taking the big airplane into combat over North Vietnam."

(Bold Emphasis mine)

What horrible features did the F8U-1 and F8U-2 possess? From what I remember hearing it was an amazing dogfighter...


KJ Lesnick

Hi.
I made a typing mistake, my apologies. It did look somewhat extreme didn't it!
I went back and checked the source and here is what it actually says:

"the F8U-3 design corrected so many of the more horrible features of the F8U-1 and 2
that any Crusader pilot's mouth would have to water at the thought of taking the big
airplane into combat over North Vietnam."

Thanks for questioning it!

 

[shockonlip]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

That's one of a handful of errors and misstatements about the F8U-3 that have been repeated in articles and on line. Both the first and second XF8U-3 first flew with the J75-P-5N engine that was rated at 24,500 lbs of thrust. After 30 flights, give or take, both were retrofitted with the YJ-75-P-6 rated at 26,000 lbs of thrust. There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. The only production F8U-3 to fly was powered by a J75-P-5N due to engine availability but the production engine was to be the P-6.

I wondered about that as well. Thanks for the correction.

But now just a thought for discussion sake.
The higher thrust claims that I read (29,000 lb thrust) I interpreted as
perhaps a goal for a YJ kind of engine, intended for the prototype, that
they backed off of when reality set in, and the engineering spec was
never changed (how many of us engineers forget to update the
documentation?).

Do you know if that was perhaps the goal?

It seems quite logical that they couldn't get the YJ motor ready and used
a production J75. Similar to the later J58 experience with the A-12 as well.
And then the YJ didn't achieve 29,000 lb thrust but did achieve 26,000.
The thrust numbers one reads are all over the place: 24,000, 25,000, 26,000,
29,000.

Thanks.

 

[shockonlip]

I'm a little hazy on the ... J58. ... From what I've found so far, the Navy's J58 didn't have a much higher rating than the J75. I'm not sure whether the improvement was to be ...

[/quote]

There is a major difference in the J75 and J58 even if the J75 could achieve the J58's
thrust levels.

That is that the J58 was intended for Mach 3 operation and the J75 was not.

The J75 had two spools and 15 stages of compression and a pressure ratio of around
11 to 1 (I think that's right - correct me if I'm wrong here).

You will notice that the J58 is single spooled, and has 9 stages of compression
and a pressure ratio of only 8.5 to 1.

So why is it important for a high mach engine to have a lower pressure ratio?

The answer is with a more typical turbojet with a higher pressure ratio, the temperature
of the air exiting the compressor and going into the burner is already at, or exceeding
turbine inlet temperature ranges at Mach 3. In other words, no room to add heat in the
burner !!

So higher mach engines from P&W, use lower pressure ratios, to keep the compressor
exit temperatures lower so that they can still add heat in the burner.

Of coarse the subsonic performance of such an engine is not as good, but as you mention
the airplanes these engines are intended for, don't spend a lot of time there.

 

[overscan (PaulMM)]

I'm a little hazy on the Navy's J58. It appears to have been intended to allow unlimited operation in afterburner so the F8U-3 and supposedly the A3J could fly at Mach 3. From what I've found so far, the Navy's J58 didn't have a much higher rating than the J75. I'm not sure whether the improvement was to be in SFC or in temperature tolerance. "Unlimited" time in AB doesn't mean much you burn all your fuel less reserve in 10 minutes. In any event, according to this report it turned out to have fundamental flow issues which were solved with a compressor bleed bypass in time to provide an engine for the Lockheed program: http://www.bobabernethy.com/pdfs/Never%20Told%20Tales%20of%20P&W3.pdf

Very nice PDF Tommy. Best summary of the J-58 I can recall is here: http://aerostories.free.fr/technique/J58/J58_01/page8.html

 

[Tailspin Turtle]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

That's one of a handful of errors and misstatements about the F8U-3 that have been repeated in articles and on line. Both the first and second XF8U-3 first flew with the J75-P-5N engine that was rated at 24,500 lbs of thrust. After 30 flights, give or take, both were retrofitted with the YJ-75-P-6 rated at 26,000 lbs of thrust. There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. The only production F8U-3 to fly was powered by a J75-P-5N due to engine availability but the production engine was to be the P-6.

I wondered about that as well. Thanks for the correction.

But now just a thought for discussion sake.
The higher thrust claims that I read (29,000 lb thrust) I interpreted as
perhaps a goal for a YJ kind of engine, intended for the prototype, that
they backed off of when reality set in, and the engineering spec was
never changed (how many of us engineers forget to update the
documentation?).

Do you know if that was perhaps the goal?

It seems quite logical that they couldn't get the YJ motor ready and used
a production J75. Similar to the later J58 experience with the A-12 as well.
And then the YJ didn't achieve 29,000 lb thrust but did achieve 26,000.
The thrust numbers one reads are all over the place: 24,000, 25,000, 26,000,
29,000.

Thanks.

The F8U-3 program was pretty typical of one with a relatively new engine involved. The engine manufacturer proposed great things in the future, with somewhat less available now, which sometimes turned out to be less than that (see Westinghouse J40). In this case, in a March 1956 Vought brochure, the initial engine was to be the P&W JT4B-21 with 25,000 pounds of thrust. It did not yet have an official Navy designation, and was therefore referred to in some instances as the J75-P (JT4B-21). (It eventually became the J75-P-5, although there is discussion of the initial flight engine being the J75-P-4; I'll sort that out one of these days.) In any event, after the flight qualification test (as opposed to the production qualification test), it was apparently flight rated at 24,500 pounds and designated as the J75-P-5N for F8U-3 flight test. The J75-P-6 was the next step in thrust rating and was to be the initial production engine, although the first production airplane flew with the -5N as there weren't enough -6s available. As far as I know, the J75 topped out at 26,500 pounds of thrust as the J75-P-19W in the F-105D. (Or back down to 24,500 pounds - you can find both numbers on the internet...)

Repeat any of the above at your own risk. Airplane guys tend to be casual and sloppy with respect to engine designations and ratings. I try not to be, but it ain't as easy to be accurate as I would like. I had a very difficult time trying to sort out the J40/J46 specification/qualification histories and I'm not sure that I got it right, much less explained it clearly. That's not because the engine specification/qualification process is not precise - It is, but what a particular engine configuration is rated at depends on the latest specification for that specific designation and those can be modified over time depending on the results of the latest qualification or recent flight experience (see J46).

 

[sferrin]

I'm a little hazy on the Navy's J58. It appears to have been intended to allow unlimited operation in afterburner so the F8U-3 and supposedly the A3J could fly at Mach 3. From what I've found so far, the Navy's J58 didn't have a much higher rating than the J75. I'm not sure whether the improvement was to be in SFC or in temperature tolerance. "Unlimited" time in AB doesn't mean much you burn all your fuel less reserve in 10 minutes. In any event, according to this report it turned out to have fundamental flow issues which were solved with a compressor bleed bypass in time to provide an engine for the Lockheed program: http://www.bobabernethy.com/pdfs/Never%20Told%20Tales%20of%20P&W3.pdf

Very nice PDF Tommy. Best summary of the J-58 I can recall is here: http://aerostories.free.fr/technique/J58/J58_01/page8.html

Now if they'd ever get an English translation of Part 2 up. . .

 

[sferrin]

IIRC the 24,500 / 26,500 apparent discrepancy for the J75-P-19W is because the extra 2k is from water injection (the "W") at takeoff.

 

[overscan (PaulMM)]

If you read Stanley Hooker's Not Much of An Engineer you will see he always aimed for higher thrust than was needed because inevitably either the thrust would be less than needed, or the airplane overweight and in need of more thrust, or both (the normal outcome).

Engine thrust levels aren't immutable. Engine thrust levels are determined by the design, the rpm its run at, the temperatures that are deemed acceptable, and the environment it is running in. Its always a balance between thrust and reliability. In 1950s Britain, engine thrusts were set by the Type Test where the specified thrust level would have to be achieved on a ground test rig for 25 hours continouously for a special flight test clearance for a prototype or 100 hours (125 hours) to get a production clearance.

In a service engine, you don't want an extra 4000lbs of thrust if it means swapping the engine out every flight for a new one, where for a world speed record attempt that might be acceptable. An engine might be rated at 24,500lbs initially but then cleared to 26,000lb after further testing.

All of which makes it hard to unravel exactly what the thrust of a particular engine were in retrospect.

 

[Tailspin Turtle]

I'm a little hazy on the Navy's J58. It appears to have been intended to allow unlimited operation in afterburner so the F8U-3 and supposedly the A3J could fly at Mach 3. From what I've found so far, the Navy's J58 didn't have a much higher rating than the J75. I'm not sure whether the improvement was to be in SFC or in temperature tolerance. "Unlimited" time in AB doesn't mean much you burn all your fuel less reserve in 10 minutes. In any event, according to this report it turned out to have fundamental flow issues which were solved with a compressor bleed bypass in time to provide an engine for the Lockheed program: http://www.bobabernethy.com/pdfs/Never%20Told%20Tales%20of%20P&W3.pdf

Very nice PDF Tommy. Best summary of the J-58 I can recall is here: http://aerostories.free.fr/technique/J58/J58_01/page8.html

Thanks, but the problem I have with that description as I do with all the others except Abernethy's is that they conflate the configuration and workings of the ultimate J58 (JT11D-20) with the initial Navy engine, which was reportedly the J58-P-2 (JT11D -?). Unfortunately, he doesn't make it clear and probably didn't know, when and why the Navy stopped funding its development.

 

[sferrin]

An engine might be rated at 24,500lbs initially but then cleared to 26,000lb after further testing.

In the case of the P-19W it seems to be pretty clear.

From WarbirdTech Vol 18

"Lastly, the engine had a water injection
system installed, which added
another 2,000lb of thrust for takeoff.
The new engine was designated
J75-P-19W, and developed a total
of 26,5001b of thrust in the afterburner
with the water injection systerm engaged.
This additional
2,000lb of thrust would prove
invaluable during the operations
conducted from Thailand, where
the heat and humidity were way
above normal. Without the water
injection, the J75-P-19W developed
24,500lb of thrust in straight afterburner,
with 14,300lb used during
flights at cruise speeds."


From Ed Rasimus on rec.aviation.military (F-105 pilot and author of "When Thunder Rolled")

"The F-105 had 36 gallons of de-ionized water in a "saddle" tank that
rode over the AB section of the engine. The J-75 was rated at 24,500
pounds in max. power and 26,500 in max with water injection. The water
was only used for take-offs and was only introduced after burner
light-off. Let there be no doubt in your mind, the 2000 pounds of
thrust was very real and readily apparent to the pilot.

The water tank was not sufficiently stressed for maneuvering flight
while containing water, so there was an automatic "dump" of the
remaining water after take-off. The dump occured when the air
conditioning/pressurization system was engaged. The interconnect
required that all "wet" take-offs be made with a/c off (ram/dump).


Water was mandatory for all take-offs with combat loads, and it used
to be fairly common for new guys recently arrived in theater to
inadvertently dump their water because they routinely turned the
pressurization on after closing the canopy, as they had done in peace
time operations. Water would be seen piddling out the bottom of the
aft section of the aircraft, they would be directed to abort, and the
spare aircraft would fill in on the combat sortie.


Water was also used for take-off augmentation on the KC-135s before
upgrade to the turbofan engines. "

 

[shockonlip]

Very nice PDF Tommy. Best summary of the J-58 I can recall is here: http://aerostories.free.fr/technique/J58/J58_01/page8.html
[/quote]

I am not sure why, but I have some reservations about this URL.
It's hard for me to put my finger on it. Perhaps it is because there is
a lot there and no references that indicate where it comes from!

I am also not familiar with the author, but his work on LeDuc and
the Bugatti aircraft do make me curious.

Regards.

 

[shockonlip]

An engine might be rated at 24,500lbs initially but then cleared to 26,000lb after further testing.

In the case of the P-19W it seems to be pretty clear.

From WarbirdTech Vol 18

"Lastly, the engine had a water injection
system installed, which added
another 2,000lb of thrust for takeoff.
The new engine was designated
J75-P-19W, and developed a total
of 26,5001b of thrust in the afterburner
with the water injection systerm engaged.
This additional
2,000lb of thrust would prove
invaluable during the operations
conducted from Thailand, where
the heat and humidity were way
above normal. Without the water
injection, the J75-P-19W developed
24,500lb of thrust in straight afterburner,
with 14,300lb used during
flights at cruise speeds."


From Ed Rasimus on rec.aviation.military (F-105 pilot and author of "When Thunder Rolled")

"The F-105 had 36 gallons of de-ionized water in a "saddle" tank that
rode over the AB section of the engine. The J-75 was rated at 24,500
pounds in max. power and 26,500 in max with water injection. The water
was only used for take-offs and was only introduced after burner
light-off. Let there be no doubt in your mind, the 2000 pounds of
thrust was very real and readily apparent to the pilot.

The water tank was not sufficiently stressed for maneuvering flight
while containing water, so there was an automatic "dump" of the
remaining water after take-off. The dump occured when the air
conditioning/pressurization system was engaged. The interconnect
required that all "wet" take-offs be made with a/c off (ram/dump).


Water was mandatory for all take-offs with combat loads, and it used
to be fairly common for new guys recently arrived in theater to
inadvertently dump their water because they routinely turned the
pressurization on after closing the canopy, as they had done in peace
time operations. Water would be seen piddling out the bottom of the
aft section of the aircraft, they would be directed to abort, and the
spare aircraft would fill in on the combat sortie.


Water was also used for take-off augmentation on the KC-135s before
upgrade to the turbofan engines. "

THANKS !!
This is awesome !!

 

[shockonlip]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

...
There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. ... .

Any integration info (airframe/engine) on the rocket engine augmentation?

The piece I quoted yesterday from Rear Admiral Gillcrist, also mentioned rocket augmentation.

Also, are we thinking that a J58 for the F8U-3 might be for just higher thrust levels at
Mach 2.6, or are we thinking that a J58 for the F8U-3 would really be for Mach 3?

Interesting question.

 

[KJ_Lesnick]

Shockonlip,

Hi.
I made a typing mistake, my apologies. It did look somewhat extreme didn't it!
I went back and checked the source and here is what it actually says:

"the F8U-3 design corrected so many of the more horrible features of the F8U-1 and 2
that any Crusader pilot's mouth would have to water at the thought of taking the big
airplane into combat over North Vietnam."

Thanks for questioning it!

What were these "more horrible" features of the F8U-1 and -2?

KJ Lesnick

 

[shockonlip]

I always wondered why the prototypes had a 29k J-75 (some sort of oddball that) while the production models would have only had 25k. You'd think they'd have kept the higher powered motor.

That's one of a handful of errors and misstatements about the F8U-3 that have been repeated in articles and on line. Both the first and second XF8U-3 first flew with the J75-P-5N engine that was rated at 24,500 lbs of thrust. After 30 flights, give or take, both were retrofitted with the YJ-75-P-6 rated at 26,000 lbs of thrust. There were design studies and performance projections with J75s of up to 30,000 lbs thrust supplemented by water injection and/or rocket engines. The only production F8U-3 to fly was powered by a J75-P-5N due to engine availability but the production engine was to be the P-6.

...
Thanks.

The F8U-3 program was pretty typical of one with a relatively new engine involved. The engine manufacturer proposed great things in the future, with somewhat less available now, which sometimes turned out to be less than that (see Westinghouse J40). In this case, in a March 1956 Vought brochure, the initial engine was to be the P&W JT4B-21 with 25,000 pounds of thrust. It did not yet have an official Navy designation, and was therefore referred to in some instances as the J75-P (JT4B-21). (It eventually became the J75-P-5, although there is discussion of the initial flight engine being the J75-P-4; I'll sort that out one of these days.) In any event, after the flight qualification test (as opposed to the production qualification test), it was apparently flight rated at 24,500 pounds and designated as the J75-P-5N for F8U-3 flight test. The J75-P-6 was the next step in thrust rating and was to be the initial production engine, although the first production airplane flew with the -5N as there weren't enough -6s available. As far as I know, the J75 topped out at 26,500 pounds of thrust as the J75-P-19W in the F-105D. (Or back down to 24,500 pounds - you can find both numbers on the internet...)

Repeat any of the above at your own risk. Airplane guys tend to be casual and sloppy with respect to engine designations and ratings. I try not to be, but it ain't as easy to be accurate as I would like. I had a very difficult time trying to sort out the J40/J46 specification/qualification histories and I'm not sure that I got it right, much less explained it clearly. That's not because the engine specification/qualification process is not precise - It is, but what a particular engine configuration is rated at depends on the latest specification for that specific designation and those can be modified over time depending on the results of the latest qualification or recent flight experience (see J46).

We could have some neat engine discussions. There are many old ones I'd love to know more about!
Thanks for the brochure!
At some point you may have to just tell me to buy your book, which I promise I will do !!

Regards.

 

[overscan (PaulMM)]

Some pics of the original design J58/JT11, from

http://www.enginehistory.org

 

[overscan (PaulMM)]

JT11/J58 info from Flight, 1959.

http://www.flightglobal.com/pdfarchive/view/1959/1959%20-%200820.html