Northrop / McDonnell Douglas ATF - YF-23 and EMD F-23

[SOC]

Doesn't that defeat the purpose of an R&D hangar?

Not at all. The purpose of the R&D hangar is to house the XB-70 and try to mask its awesomeness by surrounding it with other aircraft ;D

The R&D hangar is where test planes get displayed, yes, but if one needs to be restored it doesn't rank ahead of in-service types in priority, that's all they're saying. And I can buy that. Most of the recent restoration work has been going towards getting the Memphis Belle ready for display anyway, from what I've heard.

 

[flateric]

well, but PAV-1 was restored (kind of) already? what they going to restore now? if they want add HUD ...well, I agree

 

[SOC]

Hopefully they'll open up the weapons bay!

 

[supacruze]

That doesnt make sense.... ???
I know they rotate different aircraft thru the R&D hangar from time to time to freshen the display, so maybe they decided to pull the YF-23 for a while and display something else. I don't think the 'restoration' story stacks up because it's already been restored to static condition. Perhaps one of you guys who lives near the site can go in and get a clear definitive answer to the current situation...?

 

[Supertom]

It's not restored. It looks like it's put back together and just sitting there. Definitely looks like it's been sitting out for a while. I took a few photos of it in May - I'll post those up when I pull those out of my external drive.

 

[cookegmp]

I am lucky enough to live 7 miles away from the NMUSAF. I am quite sure it's still on display. I will try to sneak on base this week and check it out. It had definitely been restored prior to going on display. I went through the restoration hanger while it was still there and it was in poor shape. It's much better now. However, the poor X-32... :-[

 

[flanker]

I am lucky enough to live 7 miles away from the NMUSAF. I am quite sure it's still on display. I will try to sneak on base this week and check it out. It had definitely been restored prior to going on display. I went through the restoration hanger while it was still there and it was in poor shape. It's much better now. However, the poor X-32... :-[

I dont get it. One million people seems to have passed PAV-1 during restoration, but noone took pictures of the bays.

 

[sferrin]

However, the poor X-32... :-[

Only thing that could help the X-32 is a brown paper bag.

 

[OM]

However, the poor X-32... :-[

Only thing that could help the X-32 is a brown paper bag.

...And even then I still wouldn't fly'er with your joystick

 

[cookegmp]

I am lucky enough to live 7 miles away from the NMUSAF. I am quite sure it's still on display. I will try to sneak on base this week and check it out. It had definitely been restored prior to going on display. I went through the restoration hanger while it was still there and it was in poor shape. It's much better now. However, the poor X-32... :-[

I dont get it. One million people seems to have passed PAV-1 during restoration, but noone took pictures of the bays.

When I was there it really wasn't in any position where you could get a good shot of the bays. At the time it was also sitting near a restricted area that ended up being a production F-22A so the staff wasn't appreciative of someone hanging out over there with a camera.

 

[Stuka]

Just wanted to dispel the rumor about PAV-1 being removed from public display. It is currently on display in the R&D Hangar which is off site and requires a bus ride to get to. The bus only gives you 45 minutes for the Presidential and R&D Hangars which is way too short to experience everything.

 

[AAAdrone]

I could never see the R&D hangar when I was last there. I only saw the standard museum displays so I completely missed out on the good stuff. It's good to see a recent pic of PAV-1.

 

[Radical]

With regards to performance, how would the EMD F-23A compare to the YF-23? Is it more area ruled? Also, since the thrust reversers are removed, would that mean the engine housings are smaller and therefore less drag and therefore even greater speed? The F-23A is also longer, so would that make the plane more heavy?

 

[SOC]

With regards to performance, how would the EMD F-23A compare to the YF-23? Is it more area ruled? Also, since the thrust reversers are removed, would that mean the engine housings are smaller and therefore less drag and therefore even greater speed? The F-23A is also longer, so would that make the plane more heavy?

Yes, the engine nacelles would have been slimmed down. The prototypes had nacelles sized for the thrust reversers. Whether that would've made up for the weight increase brought about by the longer forward fuselage, I'm not sure.

I could never see the R&D hangar when I was last there. I only saw the standard museum displays so I completely missed out on the good stuff. It's good to see a recent pic of PAV-1.

Some of the best stuff is hidden away in the R&D hangar: the YF-12A, the YF-23A, the D-21B drone, the Kestrel, the YF-107...and the sheer insane awesomeness of the XB-70A.

 

[AAAdrone]

I saw the XB-70 already back in 2001 when it was still in one of the main hangars I think. Unfortunately I was only 10 at the time and too mentally under-developed to fully appreciate its glory. I also saw the Kestrel in the same hangar as the XB-70 and YF-22 and the like but again, this was 10 years ago. When I revisited in 2009 with my folks we completely forgot about this supposed R&D hangar (shame on me) so I never got to see any of the good stuff again.

 

[Sundog]

With regards to performance, how would the EMD F-23A compare to the YF-23? Is it more area ruled? Also, since the thrust reversers are removed, would that mean the engine housings are smaller and therefore less drag and therefore even greater speed? The F-23A is also longer, so would that make the plane more heavy?

It probably would have had less weight, as being a production design, they would have performed more analysis which would allow them to "weight optimize" the deisgn. That's probided they didn't get anything wrong and need to strengthen certain areas. Also, the longer fuselage would have given it a higher finess ration and therefore, lower supersonic (wave) drag.

It may have had the same or higher speed capabilities than the prototypes, which were already quite fast, but it's main limitation most likely would have been material/thermal limitations.

 

[Ogami musashi]

With regards to performance, how would the EMD F-23A compare to the YF-23? Is it more area ruled? Also, since the thrust reversers are removed, would that mean the engine housings are smaller and therefore less drag and therefore even greater speed? The F-23A is also longer, so would that make the plane more heavy?

It probably would have had less weight, as being a production design, they would have performed more analysis which would allow them to "weight optimize" the deisgn. That's probided they didn't get anything wrong and need to strengthen certain areas. Also, the longer fuselage would have given it a higher finess ration and therefore, lower supersonic (wave) drag.

It may have had the same or higher speed capabilities than the prototypes, which were already quite fast, but it's main limitation most likely would have been material/thermal limitations.

Not quite sure; The nacelles were slimmer, the fuselage was bulkier in addition to being longer though; It would have all the avionics inside and more than that, there's no reason the F-23 wouldn't have been striken by the same plight than the raptor that is the cost overrun & material difficulties resulting in usage of more conventionnal and heavier materials resulting in a big overweight (and performance decrease) 95's circa.


I'm sure the F-23 would have ended at the same weight more or less than the F-22.

 

[Radical]

Also, didn't the production F119 matched the YF120's thrust due to its slightly increased fan diameter? The changes from the YF-23 to the EMD F-23 doesn't seem as radical as from the YF-22 to the F-22.

 

[OM]

I saw the XB-70 already back in 2001 when it was still in one of the main hangars I think. Unfortunately I was only 10 at the time and too mentally under-developed to fully appreciate its glory. I also saw the Kestrel in the same hangar as the XB-70 and YF-22 and the like but again, this was 10 years ago. When I revisited in 2009 with my folks we completely forgot about this supposed R&D hangar (shame on me) so I never got to see any of the good stuff again.

...Damn kids. Spouting off how young they are just to make the rest of us feel that much older than dirt

 

[Mark Nankivil]

Greetings All -

A few stickers that showed up in a recent donation to the Museum...

Enjoy the Day! Mark

 

[flateric]

http://www.youtube.com/watch?v=K9ZqLukqmy8

 

[supacruze]

The video above is of the P&W YF119 as fitted to the YF-23 PAV-1.

Great find, flateric!

 

[Mark Nankivil]

Greetings All -

Found another ATF-23 decal at the Museum - rather like this one!

Enjoy the Day! Mark

 

[flateric]

thanks, Mark!

 

[supacruze]

Finally......... from Scott Lowther at upship: http://www.aerospaceprojectsreview.com/blog/?p=144

 

[Radical]

Is it me, or does Ken Scott's impressions of the F-23 EMD and the YF-23 make it seem that the F-23 is actually less bulky (except for the nose)? The fuselage and engine housings seem to be slimmed down.

 

[flateric]

o'rly?

 

[SOC]

Is it me, or does Ken Scott's impressions of the F-23 EMD and the YF-23 make it seem that the F-23 is actually less bulky (except for the nose)? The fuselage and engine housings seem to be slimmed down.

The engine nacelles definitely lost weight. They were able to be smaller as there was no longer a short-field capability requirement. That requirement drove the size of the YF-23's nacelles, as they were designed to fit thrust reversers.

 

[Sundog]

Also, if you look at the cross sections in the drawings, you will see the nacelles became more triangular in shape, not rectangular like the YF-23's, which also gives it a more slender appearance. As I commented to a friend after making these, the production version of the F-23A almost makes the YF-23 look clunky by comparison.

You should also note the F-23A was more slender than the EMD YF-23A because it was longer and would have had a higher fineness ratio than the YF-23A. That was a result of changing the weapons bay design from one deep bay to two tandem bays, the forward one for sidewinders and the rear one for AMRAAMs.

Edit: You should also note that the nacelles, as noted by SOC w/o the TR's, were moved slightly forward and they were also moved closer together; toward the centerline of the aircraft. This adds to giving the aircraft a more slender appearance.

 

[Ogami musashi]

The YF-23 always looked chunky and horrible to me; Thanks to your artworks and Orion's drawing i can finally confirm my idea that F-23A was the design that showed all the beauty of the general arrangement of the project.

 

[flanker]

1997

 

[Radical]

The F-23 EMD looks gorgeous. Although wouldn't the closer spacing of the nacelles result in reduced adherence to the Sears-Haack shape? I also noticed that the enlarged nose gives the impression of the fuselage being better contoured.

 

[AAAdrone]

IIRC The deviation from the Sears-Haack body can be attributed to the fact that Northrop was taking into account the improvements in the weapons bay that needed to be made as well as several other structural changes that needed to be made in order to make a production fighter that was actually capable of carrying all of the advanced avionics and other sorts of systems that would come to be placed on a production aircraft as opposed to a cheap bare-bones demonstrator. These design changes necessitated that sacrifices in aerodynamic shaping be made in order to optimize more for internal volume.

 

[Sundog]

Although wouldn't the closer spacing of the nacelles result in reduced adherence to the Sears-Haack shape?

In a word, no, as the Sears Haack shape is based on the volume distribution. Just because the engines are moved closer together, it wouldn't necessarily in and of itself change the volume. However, moving them closer together, partly behind the forward fuselage spine, reduces the frontal area and possibly surface area. As usual, it's always a trade-off and you can see the volume distribution in the drawings included in the article.

 

[supacruze]

Now that we can see in detail how the F-23A would have looked, all the speculation is basically over and we can see Northrop's thinking and logic in the production proposal. But I still find myself liking the shape of the YF. The YF-23 is one of the rare instances where the prototype looked as good as or better than the production version, for me anyway.

 

[Radical]

Although wouldn't the closer spacing of the nacelles result in reduced adherence to the Sears-Haack shape?

In a word, no, as the Sears Haack shape is based on the volume distribution. Just because the engines are moved closer together, it wouldn't necessarily in and of itself change the volume. However, moving them closer together, partly behind the forward fuselage spine, reduces the frontal area and possibly surface area. As usual, it's always a trade-off and you can see the volume distribution in the drawings included in the article.

The reduced frontal and surface area would reduce form and frictional drag. What's the overall effect on the wave drag due to the reshaped rear fuselage? Apparently, the higher fineness ratio due to the aircraft being longer also reduces wave drag.

As I currently understand it, minimizing wave drag is to minimize the derivative of the area of the cross sections when viewed from the front? In other words, keeping the distribution of area as uniform as possible? I'm a first year college student, so I have never taken a course on aerodynamics. I apologize for my lack of knowledge, so please bear with me.

 

[Kryptid]

Minimizing wave drag at Mach 1 has to do with making the volume distribution of the aircraft as close to that of a Sears-Haack body as possible. The actual shape of each individual part doesn't matter, just the cross-sectional area. In practice, it's not normally possible to get it identical to such an ideal. An average fighter has about twice the wave drag efficiency factor as a Sears-Haack body of similar total volume.

Above Mach 1, the ideal volume distribution for reducing wave drag changes. You need to base the volume distribution on so-called "Mach plane cuts" which are derived from the angle that shockwaves form at that given speed (the higher the speed, the sharper the angle). This is difficult to "eyeball" so I imagine there's a lot of computer work involved these days in shaping an aircraft for low drag at high Mach numbers. A good design can reach low wave drag at Mach 1 and speeds above by using blended shapes (like we see in the B-1). Stealth aircraft often have blending between various design features (wing, fuselage, canopy, etc.) so that likely aids in a similar fashion.

 

[Radical]

Has the YF-22's supercruise speed with the YF-119 engine been declassified? According to Paul Metz, the YF-23 reached mach 1.43 with those engines.

 

[F-14D]

Has the YF-22's supercruise speed with the YF-119 engine been declassified? According to Paul Metz, the YF-23 reached mach 1.43 with those engines.

I don't think that speed remained classified, if it ever actually was. The only one that stayed classified, and still is AFAIK, was the YF-23 with the YF120 engines.

 

[AAAdrone]

I don't think the performance figures for the YF-22 were ever classified with regards to their cruise performance with each engine. I can't recall what the YF-22's supercruise speed was with the YF-119 but the only classified figure was the YF-23 and YF-120 combo which is merely stated as "Mach 1.6+" and said figure remains classified to this day.