Business and regional jets

[ysi_maniac]

Reworking HS 125

[The Big Gimper]

I like the four engine design. Scale-o-rama with a 1/144 airliner.

[Jeffry Fontaine]

The jet engine pods from the Italeri/Testors AC-119 kit would work very well for such a modification project in 1:72nd scale  :)

[GTX_Admin]

What about something such as a Learjet with the twin small engines replace by something such as a P&W F100 in the tail fed by a single over fuselage intake (with either ramp or shock cone).  One supersonic business jet!

[elmayerle]

Need a thinner and re-profiled wing, too.  Current Learjet wing gets severe "Mach tuck" at Mach=.85 which creates a severe nose-down pitching moment that can very easily lead to a great smoking hole in the ground.

[GTX_Admin]

New wing is a definite.

[ysi_maniac]

Like this?

[GTX_Admin]

Yep that would work.  A variable intake might be useful to get the best performance though

[GTX_Admin]

Sweet!

[jcf]

Brit concepts.






Blackburn




Originally a concept for a VTOL military liaison aircraft, considered for exec role, centre fan lift.





Two SR.177 based concepts.

[ysi_maniac]

Thanks for posting.

[elmayerle]

B.114 looks like an expansion on the Miles Student jet trainer.  Some interesting concepts there and the ones with lift fans remind me of some studies Ryan did of mating lift fans with an early-model Learjet.

[M.A.D]

What about Contingency Fighter's aka Emergency Fighter adoption of business jets for military roles eg: Interceptor / Ground Attack? Or has this already been done in other forums? (if so, I apologise, and please disregard)


M. A. D

[elmayerle]

What about Contingency Fighter's aka Emergency Fighter adoption of business jets for military roles eg: Interceptor / Ground Attack? Or has this already been done in other forums? (if so, I apologise, and please disregard)

There were studies of interceptor versions of the Learjet 35/36 with a radar on the top of the vertical tail and three missiles, 2x AMFAAM and 1x IRAAM, under each wing.  You could also adapt the Learjet wing to carry ground attack munitions and add suitable sensor designator elements either on the fuselage or at the front end of the tip tanks.

[ScranJ51]

The Royal Navy used one or two (actually this is number 4) for Fleet Support in Scran Land:

HS125-3 by David Freeman, on Flickr

HS125-2 by David Freeman, on Flickr

HS125-1 by David Freeman, on Flickr

[Acree]

The US Drug Enforcement Agency (DEA) use Cessna Citation 550s equipped with AN/APG 66 radar and other sensors on intercept duties. See here: https://www.cbp.gov/sites/default/files/documents/FS_2015_C-550%20Citation.pdf

[jcf]

What about Contingency Fighter's aka Emergency Fighter adoption of business jets for military roles eg: Interceptor / Ground Attack? Or has this already been done in other forums? (if so, I apologise, and please disregard)


M. A. D

Dime-a-dozen in Whif-verse, and not uncommon in the “real world”, and all far
more boring than the reverse: bizjets/exec aircraft based on military aircraft.

[Volkodav]

What about Contingency Fighter's aka Emergency Fighter adoption of business jets for military roles eg: Interceptor / Ground Attack? Or has this already been done in other forums? (if so, I apologise, and please disregard)


M. A. D

Dime-a-dozen in Whif-verse, and not uncommon in the “real world”, and all far
more boring than the reverse: bizjets/exec aircraft based on military aircraft.

Well the original Lear was based on a fighter / ground attack aircraft and the Mystere business jets were evolved from the like Nb armed fighters.

[elmayerle]

Yep, the Learjet, especially the Model 23, uses the wings, tail surfaces, and tip tanks of the FFA P-16.  The wings on the Models 23/24/25, 28/29, 35/36, 55, 60 all share this ancestry.  Only the comparatively recent Model 45 has a new wing.

[GTX_Admin]

It would be interesting to see some other fighters developed into business jets:

• Mirage III/2000?
• Mirage F.1
• F-4 Phantom II
• F-104
• F-14
• F-16

[GTX_Admin]

Speaking of which, here is a theoretical F-111 Executive jet I did ages ago:

[GTX_Admin]

And there was the real world MiG-25 proposal:

[elmayerle]

Then there's Cessna's Model 407/407A derivatives of the T-37 as well as the "executive transport" version of the F-106 that Convair proposed (really want to model that one in 1/48).  For that matter, there's the TU-116, a more direct conversion of a TU-95 airframe for a special personnel transport than the TU-114 airliner.

[GTX_Admin]

[GTX_Admin]

Another conversion:

[Jeffry Fontaine]

I think that Vampire BizJet would look right at home with Gerry Anderson's Thunderbirds. 

[jcf]

More SARO, two of the different configurations studied during the P195 & P202 design
process.


Four engines buried in the rear fuselage, tiltable for short takeoff.

[ysi_maniac]

Regional STOL

Found in DeviantArt. I love it

[GTX_Admin]

 

[ysi_maniac]

Speaking of which, here is a theoretical F-111 Executive jet I did ages ago:

Greg, may I ask for your licence to build this one day?

[GTX_Admin]

Go for it!

[ysi_maniac]

  OK!

[GTX_Admin]

It started off as a business jet:

https://youtu.be/-MGJnL-Smk4

[kitnut617]

In the latest issue of Air-Britain's Aviation World, there's an article about a De Havilland (UK) reginal airliner called the D.H.123.  I can't find anything on the internet other than what's on SPF (no pictures), but it looks like a fore runner to a Dash 8

[apophenia]

The powerplant for the D.H.123 - the de Havilland Gnome P.1000 turboprop - had an interesting shaft arrangement. Here is a bit on the P.1000 from Flight 18 March 1960:

"D.H. Gnome P.1000 Free-turbine turboprop. Ten-stage compressor with variable-incidence inlet guide vanes and first three stators, annular combustion chamber with 16 burners, two-stage compressor turbine, independent single-stage power, turbine driving through rear reduction gear, high-speed top shaft and front reduction gear to suit propeller speeds from 1,245 to 1,550 r.p.m. Overall length, 87.3 in; height, 31.55 in; width, 17 in; dry weight, with starter and accessories, 555 lb; mass flow, 12.4 lb/sec; pressure ratio, 8.3:1; max rating (5 min.), 1,000 s.h.p. + 144 lb thrust at 26.260 r.p.m. (20,000 power-turbine r.p.m.) with s.f.c. of 0.669 lb/hr/s.h.p.; recommended cruise, 800 s.h.p. + 120 lb at 25,120/17,000 r.p.m. with s.f.c. of 0.728; the P.1200 will have corresponding ratings of 1,150 and 900 s.h.p. with sf.c. of 0.657 and 0.71.

https://www.flightglobal.com/FlightPDFArchive/1960/1960%20-%200370.PDF

Flight 20 July 1961 reported that "The first P.1000 ran in September 1960, and a Dakota is now being fitted with two of these engines for flight-test purposes." Anyone know if that TurboDak actually flew?

https://www.flightglobal.com/FlightPDFArchive/1961/1961%20-%200980.PDF

[tankmodeler]

The powerplant for the D.H.123 - the de Havilland Gnome P.1000 turboprop - had an interesting shaft arrangement. Here is a bit on the P.1000 from Flight 18 March 1960:

"D.H. Gnome P.1000 Free-turbine turboprop. Ten-stage compressor with variable-incidence inlet guide vanes and first three stators, annular combustion chamber with 16 burners, two-stage compressor turbine, independent single-stage power, turbine driving through rear reduction gear, high-speed top shaft and front reduction gear to suit propeller speeds from 1,245 to 1,550 r.p.m.

The PT6 simplified the whole engine package by doing something non-intuitive, having the air inlet at the back and the exhaust at the front.

It costs you some extra ducting, which, if you do it right can actually act to reduce engine inlet noise, so it's not a total loss, but what that does is puts the free turbine, and the required gearbox, up front, right next to the prop, so there's no extension shaft, no need to sidestep the engine with the prop shaft or to run the prop shaft up inside the turbine. It simplified things amazingly. Everything, from engine build, and test to maintenance and up rating. Compared to previous turboprops PT-6s are incredibly simple engines.

Paul

[apophenia]

Good points Paul. As you say, a reverse-flow arrangement would greatly simplify things ... perhaps explaining to DH why GE never pursued a turboprop T58 
(Actually, that Gnome P.1000 shaft reminded me a little of the PT6T TwinPac  arrangement.)

Maybe de Havilland would have been better off designing a D.H.123 with pusher props?

[GTX_Admin]

In the latest issue of Air-Britain's Aviation World, there's an article about a De Havilland (UK) reginal airliner called the D.H.123.  I can't find anything on the internet other than what's on SPF (no pictures), but it looks like a fore runner to a Dash 8

I assume the Aviation World article doesn't include any images?

[kitnut617]

In the latest issue of Air-Britain's Aviation World, there's an article about a De Havilland (UK) reginal airliner called the D.H.123.  I can't find anything on the internet other than what's on SPF (no pictures), but it looks like a fore runner to a Dash 8

I assume the Aviation World article doesn't include any images?

Actually quite a few, just can't find any on the internet. It's one of those discoveries that might not have been found except for some alert fellow who knew what he was looking at.

Just had a look at the article again, it's four pages long of typical magazine size pages. Some 3-Veiws and a couple of artist impressions. And some seating arrangements. Fellow's name who salvaged the documents is Tony Thatcher.

[GTX_Admin]

Ta - might need to source a copy