• Hi Guest! Forum rules have been updated. All users please read here.

Gulfstream X-54A

Matej

Multiuniversal creator
Joined
Feb 13, 2006
Messages
2,616
Reaction score
92
Website
www.hitechweb.genezis.eu
The next X-plane designation X-54 was assigned to Gulfstream Aerospace. Only a short info is available from Andreas site:

Supersonic experimental aircraft to conduct flight research. Capable of generating relevant ground sonic boom signatures to gather scientific data in support of NASA and a regulatory change process.
http://www.designation-systems.net/usmilav/412015-L(addendum).html

I started the search for the additional info, so keep your fingers crossed. I am mainly interested in if it is a new design (related to SSBJ research), or the modified of-the-shelf plane.
 

Andreas Parsch

CLEARANCE: Secret
Joined
Mar 2, 2006
Messages
245
Reaction score
6
Hi Matej,

thanks for looking into this as well :). When I received the "X-54A" MDS record, I tried of course to get information on the project, but couldn't find anything relevant (and felt a bit stupid :-[). Problem is, searching for things like Gulfstream/NASA/supersonic apparently only returns the now completed "Quiet Spike" (modified F-15) program of 2006/07.

Regards
Andreas
 

Matej

Multiuniversal creator
Joined
Feb 13, 2006
Messages
2,616
Reaction score
92
Website
www.hitechweb.genezis.eu
Till now I contacted five (!) persons @ Gulfstream and nobody was able/willing to tell me anything. :-\ But the hunt continues...
 

TinWing

CLEARANCE: Top Secret
Senior Member
Joined
Jan 3, 2006
Messages
888
Reaction score
43
It might seem like an inane observation, but isn't the G650 supposed to be capable of near transonic cruising speeds?

Could it be that NASA was involved in research for a transonic project, not supersonic?
 

CammNut

CLEARANCE: Secret
Joined
Feb 1, 2007
Messages
296
Reaction score
4
Here is NASA's statement on the subject:

"NASA supported Gulfstream in its application for the X designation because support of a government agency is required. NASA views it as a placeholder. NASA is not working actively with Gulfstream on this project and is not discussing cooperation. This does not preclude future discussions related to cooperation on this topic."
 

Andreas Parsch

CLEARANCE: Secret
Joined
Mar 2, 2006
Messages
245
Reaction score
6
CammNut said:
Here is NASA's statement on the subject:

"NASA supported Gulfstream in its application for the X designation because support of a government agency is required. NASA views it as a placeholder. NASA is not working actively with Gulfstream on this project and is not discussing cooperation. This does not preclude future discussions related to cooperation on this topic."
Thank you very much for this information! So it's essentially a Gulfstream private project, and they persuaded NASA to get them a "prestigious" X-plane designation :-\ .
 

CammNut

CLEARANCE: Secret
Joined
Feb 1, 2007
Messages
296
Reaction score
4
Gulfstream isn't saying much. I wonder if the designation was applied for as part of the defunct "Super 10" consortium. Even if it is dormant for now, Gulfstream has said all along that a demonstrator is needed to establish what is an "acceptable" level of sonic boom, something it says is essential to changing the US regulations banning supersonic flight over land. They are aiming for an international rule change by 2016, at which point Gulfstream would launch development of a quiet supersonic bizjet. Plenty of time, then, to build and fly a demonstrator.
 

gtg947h

CLEARANCE: Confidential
Joined
Apr 10, 2008
Messages
89
Reaction score
11
Matej said:
Till now I contacted five (!) persons @ Gulfstream and nobody was able/willing to tell me anything. :-\ But the hunt continues...
They aren't just going to give out information over the phone to random people, you know...
 

Matej

Multiuniversal creator
Joined
Feb 13, 2006
Messages
2,616
Reaction score
92
Website
www.hitechweb.genezis.eu
And who said that I do it this way? Well, if NASA or any of the governmental institution is not involved in the project, than that is not a good news. I still remember some projects from Scalled composites in mid 90s - it was almost impossible to get any information about them.
 

Just call me Ray

CLEARANCE: Top Secret
Joined
Aug 26, 2007
Messages
680
Reaction score
9
I was reading the Designation-Systems.net page and did a Google search out of curiosity which lead me...right back to this thread....yeah.... ::)


Anyway, based what little information I have, it suggests that the aircraft in question will be powered by two RR Tays - just like the GII/III, so I'm thinking this is just a modified GII/III (most likely a III, I'll bet) that will be put through some supersonic dives, or at least to gather high-speed or specialized data.

In fact I'm willing to bet it's that new thing they got flying with those weird donut-shaped winglets.
 

FalconPilot

CLEARANCE: Restricted
Joined
Jul 31, 2008
Messages
2
Reaction score
0
The X-54A is not the S-21. The S-21 aircraft was a proposed joint venture between Sukhoi (OEM of the SU-25, 27, 31, etc) and Gulfstream. That project/coordination was cancelled in the early 90's.
Gulfstream does not consider sustained supersonic flight practical/economical/marketable with the current subsonic restriction overland. They have clearly stated they will only pursue a SSBJ if the current laws can be ammended.
Informed friends of mine say the X-54A will be a technology demonstator based on an F-104 powered by a PW F100-229. The picture I saw did, in fact include "loop" winglets.

BTW - GIIs and GIIIs are powered by RR Speys, not Tays. The Tay is on the GIV/G450.

cheers....
 

sferrin

CLEARANCE: Above Top Secret
Senior Member
Joined
Jun 3, 2011
Messages
12,909
Reaction score
980
FalconPilot said:
Informed friends of mine say the X-54A will be a technology demonstator based on an F-104 powered by a PW F100-229.

So they're finally going to fly the X-27 huh? ;) Sounds fishy to me.
 

Attachments

Kim Margosein

CLEARANCE: Confidential
Joined
Feb 10, 2007
Messages
103
Reaction score
5
So they're finally going to fly the X-27 huh? Sounds fishy to me.

Actually, they will fly two. That's how they arrived at X-54

But seriously folks, is this related to a quiet supersonic project using a modified F-5?
 

quellish

I am not actually here.
Senior Member
Joined
Aug 6, 2007
Messages
2,084
Reaction score
54
These patents reveal quite a bit.


https://www.google.com/search?tbo=p&tbm=pts&hl=en&q=ininventor:%22Preston+A.+Henne%22
https://www.google.com/search?tbo=p&tbm=pts&hl=en&q=ininventor:%22Timothy+R.+Conners%22

http://www.google.com/patents/US8083171?dq=inassignee:%22GULFSTREAM+AEROSPACE+CORPORATION%22&ei=QeopT8_HGcitiQLErvjdCg

http://www.flightglobal.com/news/articles/ebace-tay-test-touts-gulfstream-supersonic-business-jet-action-341587/
 

sferrin

CLEARANCE: Above Top Secret
Senior Member
Joined
Jun 3, 2011
Messages
12,909
Reaction score
980
"The planned engine, a custom designed variant of a Pratt & Whitney JT8-219, will feature a bypass ration of 1.7:1 and maximum take-off thrust of 21,700lb, although the engine will be flat-rated to a lower thrust. "

That seems like an. . .odd choice for Mach 1.7 cruise.
 

Helodriver

CLEARANCE: Restricted
Joined
Aug 26, 2008
Messages
6
Reaction score
1
Aerion is also planning to use the JT8. I wonder if they are working with Gulfstream.

http://en.wikipedia.org/wiki/Aerion_SBJ
 

iverson

CLEARANCE: Secret
Joined
Sep 24, 2009
Messages
261
Reaction score
62
sferrin said:
That seems like an. . .odd choice for Mach 1.7 cruise.
Not all that odd. The Volvo RM8 used in the Viggen was a JT-8 derivative. So there is a precedent.
 

sferrin

CLEARANCE: Above Top Secret
Senior Member
Joined
Jun 3, 2011
Messages
12,909
Reaction score
980
iverson said:
sferrin said:
That seems like an. . .odd choice for Mach 1.7 cruise.
Not all that odd. The Volvo RM8 used in the Viggen was a JT-8 derivative. So there is a precedent.
It wasn't designed to supercruise at Mach 1.7 and had an afterburner for supersonic flight. Little bit different.
 

quellish

I am not actually here.
Senior Member
Joined
Aug 6, 2007
Messages
2,084
Reaction score
54
Helodriver said:
Aerion is also planning to use the JT8. I wonder if they are working with Gulfstream.

http://en.wikipedia.org/wiki/Aerion_SBJ
According to the article referenced earlier:
http://www.flightglobal.com/news/articles/ebace-tay-test-touts-gulfstream-supersonic-business-jet-action-341587/

"Pres Henne, Gulfstream's senior vice-president of programmes, has confirmed that the company "recently" tested a supersonic nacelle design on one engine of a Rolls-Royce Tay 651-powered Gulfstream IV on the ground."

"The nacelle design, although not revealed, could be similar to a US patent that Gulfstream applied for in February. With the proposed nacelle, the patent states that an engine with 15,000lb maximum take-off thrust (67kN) and bypass ratio of 3:1 could power an SSBJ at a cruise speed of Mach 1.7. Those thrust and bypass characteristics closely match those of the Tay 651. "

While Aerion...

"The company is proposing an eight-passenger, M1.6 aircraft for $80 million per copy, ready five years after a to-be-determined programme launch."

"The planned engine, a custom designed variant of a Pratt & Whitney JT8-219, will feature a bypass ration of 1.7:1 and maximum take-off thrust of 21,700lb, although the engine will be flat-rated to a lower thrust."
 

Stargazer2006

CLEARANCE: Above Top Secret
Staff member
Senior Member
Joined
Jun 25, 2009
Messages
13,242
Reaction score
350
An artist's concept of a production N+1 design, and another picture of the N+2 phase design, showing the dispersion of the sonic waves alongside the nose boom. The X-54A LBEV will be a sub-scale demonstrator for that technology.

NOTE: The X-54A is part of the Fundamental Aeronautics Supersonic Project, which has defined N+1, N+2 and N+3 designs (we have a topic on the latter, I believe).

Just as a reminder:
  • N+1 is the "conventional" passenger transport design
  • N+2 is the Small Supersonic Airliner
  • N+3 is the Efficient, Multi Mach Aircraft
 

Attachments

Stargazer2006

CLEARANCE: Above Top Secret
Staff member
Senior Member
Joined
Jun 25, 2009
Messages
13,242
Reaction score
350
NASA Focuses Supersonic Effort On Low-Boom Propulsion (excerpt)
By Guy Norris, Graham Warwick
Source: Aviation Week & Space Technology

While progress is being made, the rear of the aircraft—and particularly the propulsion system—remains the most challenging to shape for low boom. This is because of the highly three-dimensional flowfield and complex interaction between the fuselage, wing, empennage and nacelles. Shocks caused by the inlet flow and exhaust stream have to be controlled while meeting engine operability and accessibility requirements. Gulfstream is coming to grips with the problem as it refines the design of a supersonic business jet and its potential precursor, the still-unfunded X-54 Low Boom Experimental Vehicle. The X-54 would prove that a complete aircraft can be shaped for low sonic boom and be flown to gather the data on public acceptance of shaped booms needed to convince regulators to change the rules barring supersonic flight over land—an essential step for market viability.
Designing a low-boom nacelle is difficult. Engine flow requirements set the inlet and nozzle size; the diameter of the engine and its external accessories determine the nacelle's girth. These set the intake cowl slope and nozzle boat-tail angle, which govern the strength of the forebody compression field and aft-body expansion zone in supersonic flight. These elements can be reduced by stretching the nacelle, but that increases weight and losses.
Working with the Rolls-Royce Tay turbofan for the X-54 demonstrator, Gulfstream hit a problem: The engine's externally mounted accessory gearbox caused a large nacelle bulge that adversely effected sonic boom. Its answer was the high-flow nacelle bypass concept. This encloses the powerplant in an aeroshell with a sharp intake lip and smooth internal flowpath that routes much of the captured air around the engine and gearbox with low losses. Curved channels overcome the problem of the gearbox blocking the flow.
The concept helps in other ways, allowing Gulfstream to design an axisymmetric inlet that minimizes both drag and boom. Inlet spillage, caused when intake supply exceeds engine demand and air overflows the cowl lip, increases supersonic drag and sonic boom. To avoid spillage, the inlet must capture the centerbody tip shock, but with a conventional external-compression inlet, zero spillage is almost impossible to achieve. With the high-flow nacelle, the engine cowl is inside the aeroshell, allowing the outer intake to capture and bypass spillage from the inner inlet.
Another interesting passage is this:
While Gulfstream is working on what NASA calls the “N+1”—or first-generation quiet supersonic transport—Boeing and Lockheed Martin are studying N+2 and N+3 concepts for notional 2025 and 2035 timeframes, respectively. Each generation is larger, with more-stringent targets for sonic boom and airport noise. The concepts tunnel-tested in 2011 were aimed at NASA's N+2 goals for a 35-70-seat, Mach 1.6-1.8 jet with an 85-PLdb boom and noise 12 EPNdb below Stage 4.
Full four-page article:
Page 1 | Page 2 | Page 3 | Page 4
 

Stargazer2006

CLEARANCE: Above Top Secret
Staff member
Senior Member
Joined
Jun 25, 2009
Messages
13,242
Reaction score
350
The Gulfstream Quiet SpikeTM is a telescoping forward fuselage extension that s the bow shock of the classic N-wave pressure signature generated by aircraft traveling at supersonic speeds. The bow shock is broken up into sequence of weak shocks that propagate parallel to each other without coalescing. The resulting rise time to peak overpressure in the ground signature is increased from two or three milliseconds to thirty or forty milliseconds, significantly reducing the loudness. The development history of the Quiet Spike concept is traced from initial conception up to the design of a flight test configuration. Early aerodynamic and structural tests matured the concept from one viewed with skepticism to one deemed possible.

Source: abstract for Development of the Gulfstream Quiet SpikeTM for Sonic Boom Minimization
AIAA Paper 2008-0124, 2008 (not available online)
http://www.aric.or.kr/treatise/journal/content.asp?idx=100243

A recent related document online:
 

Stargazer2006

CLEARANCE: Above Top Secret
Staff member
Senior Member
Joined
Jun 25, 2009
Messages
13,242
Reaction score
350
In my opinion, the Gulfstream X-54-related aircraft that might be at Farnborough (according to rumors) will likely be the F-15B demonstrator fitted with the "Quiet Spike" in the nose. Last I read was that the proper X-54 still waited to be funded!

I'm enclosing a picture of the demonstrator, as well as two three-view arrangements of the "N+2" projects from Boeing and Lockheed Martin (not to be mistaken for the "N+3" concepts!).

Last diagram is interesting because it presents some of these projects in perspective with the Concorde's own performance/environment data. But mostly because the design attributed to "Team D1" looks very Gulfstream-ish.
 

Attachments

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
6,915
Reaction score
1,904
Thanks Star! You are really one of the outstanding guy.
 

quellish

I am not actually here.
Senior Member
Joined
Aug 6, 2007
Messages
2,084
Reaction score
54
Stargazer2006 said:
In my opinion, the Gulfstream X-54-related aircraft that might be at Farnborough (according to rumors) will likely be the F-15B demonstrator fitted with the "Quiet Spike" in the nose. Last I read was that the proper X-54 still waited to be funded!
NASA 836 hasn't had the Gulfstream spike fitted for a while:
http://www.nasa.gov/topics/aeronautics/features/shockwave_probes.html
I have some good close up photos of it from when the spike was attached though
 

Stargazer2006

CLEARANCE: Above Top Secret
Staff member
Senior Member
Joined
Jun 25, 2009
Messages
13,242
Reaction score
350
quellish said:
I have some good close up photos of it from when the spike was attached though
Feel free to share some with us my friend!! ;)
 

Stargazer2006

CLEARANCE: Above Top Secret
Staff member
Senior Member
Joined
Jun 25, 2009
Messages
13,242
Reaction score
350
Cool pics. Thanks for sharing! ;)
 

robunos

You're Mad, You Are.....
Senior Member
Joined
May 1, 2007
Messages
1,842
Reaction score
160
Now that's an X-Plane....... ;D


cheers,
Robin.
 

piginapoke

I really should change my personal text
Joined
Mar 11, 2013
Messages
14
Reaction score
0
No new word on the X-54?
No Farnborough announcement. Any results from the F-15 trials?

Maybe the biggest problems are to do with environmental impact concerns?
 
Top