Digging up bones: F/B-23 Revisited

I decided it best to confine this to a new post, rather than bump year-old+ topics.

Background: Following an observation that many of the aircraft designed for sustained supersonic flight (F-104, B-1, B-47, etc) had their horizontal stabilizers mounted above the root of the vertical stabilizer, I decided to do some more research into supersonic flight design concerns and history to see why this might be. I then stumbled across a very interesting paper that made me instantly realize why the F-23 was designed with such an awkward wing design.

aero.stanford.edu... - This is a PDF

The directly-relevant discussion begins on page 13 of the .pdf; though the prior is also an interesting bit of reading and/or photo/graph browsing (a diagram and a graph are worth more than a book of technical descriptions, in my opinion....).

The observant among us will quickly take note of the similarity between this design and the wing design of the YF-23.

The paper pretty much explains why this wing design is superior for practical sustained supersonic flight - I'll let it do the explaining.

However, when it comes to building a bomber with super-cruise capabilities, the wing was shown to reduce the effects of supersonic overpressure (sonic boom), have a much better tolerance for structural stresses (reduce maintenance concerns), and has much more volume for fuel while providing a lower-drag surface with higher lift potential.

The design also has particular advantages in when reducing the radar cross section of an aircraft. The following article will go into much more detail about LO design concerns.

www.qsl.net...

The bottom Line:

I found this article particularly interesting with regards to the Interim Bomber competition and the rumors about the F/B-23. It would appear Northrop-Grumman has a very stable base to create a supercruise-capable strike/bomber platform from - especially with regards to range and fuel efficiency.

Even though the Interim Bomber competition has dropped the supercruise requirement..... a design that is designed to peak in performance at high subsonic and supersonic speeds and has supercruise as a bonus with no adverse impact on cost.... If Northrop-Grumman can put theory into practicality.... they will likely be sitting pretty in the Interim Bomber competition.

There was a photo posted a week ago somewhere (so much for being precise, lol) that showed a B-2 in a high-subsonic low level flight (at an airshow maybe?) with clouds of water vapor forming behind the wings, similar to photos of fighters breaking the sound barrier at low-level on a humid day.

Even though the B-2 is not supersonic, it raised some questions about whether this design is capable of supercruise.

Good post!

reply to post by Aim64C


Great post. Its going to take me a bit to digest the pdf but a facinating study none the less and right in my backyard literaly.

We know that both YF-23 went missing for some time. Both the one that was "supposed" to be at Edwards and the one on loan to the Western Museum of Flight. We had a thread last year where we were able to track where the airframes were but where they had been remians a mystery.

I have always been a fan of the YF-23 and the thought of it living on in some incarnation is awesum IMHO.

There wasn't much time where they had missing and not been able to track from what I remember about the thread. Here it is just review and a link to the thread. I'm going to have to give the pdf a read as well. since it sounds interesting for sure in regards to f-23 design and the fact in my opinion that the f-23 wing found its way onto the F-22 production model.

YF-23A "Black Widow II" PAV-1 (S/N 87-800)
-Late 1990- ATF flight test program ends (Global Security)
-April 1991- ATF contract awarded to the yf-22 (Global Security)
-Dec 1993- PAV1 arrives at NASAs Dryden Flight Center (NASA)
-May 1996- PAV1 released from NASA to WPAFB Museum (NASA)
-??? 1996- PAV1 moved to "Contractor Row" Taxiway on EAFB.(shadowhawk)
-Oct 1996-PAV1 Photographed @ Edwards AFB air show (Søren Augustesen)
-??? 1997- PAV1 Sighted at EAFB (Anonymous posting)
-Mar 2000- PAV1 transported to WPAFB Museum by C-5(shadowhawk)
-??? 2002- PAV1 photographed at WPAFB Museum restoration hanger (Phil Callihan)
-??? 2004-PAV1 photographed in WPAFB Museum restoration hanger (Gary Brossett)
-June 2008-PAV1 wings reattached and restoration almost complete.(WPAFB-Museum)

YF-23A "Black Widow II" PAV-2 (S/N 87-801)
-Late 1990- ATF flight test program ends (Global Security)
-April 1991- ATF contract awarded to the yf-22 (Global Security)
-Dec 1993- PAV2 arrives at NASAs Dryden Flight Center (NASA)
-Oct 1995- PAV2 released by NASA to WMF (NASA)
-??? 2002- PAV2 photographed @ WMF (Phil Collins)
-Jan 2004- PAV2 seen at WMF contact made with Dana (Spyhawk)
-June 2004- PAV2 wings removed by Northrop for restoration (Edward Gronenthal)
-July 2004- PAV2 whole airframe removed to Northrop for restoration (Dana Muelot)
-Aug 2004- PAV2 restoration completed by Northrop for local Air Fair(Dana Muelot)
-??? 2006- PAV2 photographed outside Northrop El Segundo building(Dan Tanna)
-June 2007- PAV2 said to be sitting outside Northrops El Segundo building (racerzeke)
-Feb 2008- PAV2 possible sighting of airframe outside of Northrop El Segundo building
-July 2008- PAV2 sighting of airframe at Northrop El Segundo building (sagelake)

www.abovetopsecret.com...

[edit on 28-5-2009 by Canada_EH]

I always liked the F-23 design.

A lot of folks speculate that this current generation may be the last for manned fighters. There are not a lot of air forces in the world that have the capability to go against supercruise/stealth/fly by wire/standoff aircraft.

Some nations certainly have the technology but not the skill.

My gut says the F-23 chassis is still around being used as a platform for some really cool secret squirrel stuff.

PS - Here is that B-2 image. Not that it's pertinent, just cool.

[atsimg]http://files.abovetopsecret.com/images/member/14d5c6e36503.jpg[/atsimg]

I think I found PAV-2 (Gray Ghost):

Northrop Grumman El Segundo


I don't know how recent it is.

I was at WPAFB a couple of years ago but PAV-1 wasn't on display yet.

reply to post by emsed1


Yup PAV-2 is displayed by Northrop at the side of one of their buildings. The location is highlighted in the timeline I created and copied to this thread "-July 2008- PAV2 sighting of airframe at Northrop El Segundo building (sagelake) ". As for the B-2 high subsonic image your correct its sub sonic but the speed doesn't have to be that high to form Prandtl-Glauert condensation clouds. The B-2's own aerodynamics keep it from being super-cruise capable and the Prandtl-Glauert effect has been mislabeled a number of times as a sound barrier cone which has lead to the confusion.
en.wikipedia.org...–Glauert_singularity

reply to post by Canada_EH


Very cool info!

I always thought of it as sort of 'cavitation' where an object sticking out into an airstream starts to create a low pressure area. The way it made sense (inside my head anyway) was sort of like a thunderstorm building. The hot humid air gets sucked into an area of low pressure and expands, cooling off and precipitating.

I have to admit though until I saw that B-2 photo the other day I thought the 'shock cone' only happened at transonic or supersonic speed.

Cool thread!

Originally posted by emsed1
PS - Here is that B-2 image. Not that it's pertinent, just cool.

[atsimg]http://files.abovetopsecret.com/images/member/14d5c6e36503.jpg[/atsimg]

Not that this is related in any way to your posts, but when I saw this picture I couldn't help noticing how much the B-2, at this angle, resembles a bird in flight. The curvature of the nose looks so much like a beak, the front proportions look so much like the proportions of a bird head, and the tail looks like a bird tail. I'm sure this is obvious to most of you...... I guess I'm just looking at it from an artistic point of view and liked the photo.

reply to post by 2manyquestions


It actually does!

It sor of looks like a sparrow or something with it's head up and wings back.