Author Topic: Аэробус - the Soviet Aerobus Program  (Read 818 times)

Offline apophenia

  • Suffered two full days of rapid-fire hallucinations and yet had not a single usuable whif concept in the lot !?!
  • Patterns? What patterns?
Аэробус - the Soviet Aerobus Program
« on: June 06, 2017, 06:13:46 AM »
Аэробус - the Soviet Aerobus Program

I've been reading about the Soviet Аэробус (Aerobus) project ... and most of my original whif ideas turned out to be RW projects. For my whif series, I decided to enlarge the program. In this scheme, the Soviet Aerobus project is divided into two components in September 1968. The original project became the Sredniy Aerobus or Medium(-range) Aerobus. The second component was for a Prigorodnyy Aerobus or Commuter Aerobus -- a smaller, lower-capacity, short-range airliner.

Antonov OKB and the Aerobus Program

One RW Aerobus non-starter was the Antonov An-122 (the second type with that designation). The An-122 Aerobus project was a warmed-over An-22 Antei military transport complete with turboprops. I decided to take that Antonov project a few steps further as the An-122P. The result is a blend of Antei transport and scaled-down components from the An-124 strategic transport which Antonov had begun to work with at that time.

(Top) Antonov An-122LL Aerobus demonstrator prototype

The An-122LL Aerobus demonstrator featured a modified An-22 fuselage mated to new wings based on Antonov's An-124 work. The An-122LL sported a completely new twin-tail with swept surfaces. The latter was adopted to allow the aircraft to fit into smaller hangars. Power was to be be 4 x Soloviev D-30T low-bypass turbofan engines.

Initial official responses to the An-122LL were luke-warm. The advantages of developing the aircraft from an existing airframe were obvious but the Aerobus program was also intended to enhance the prestige of the Soviet aerospace industry. On the technical side, the twin tails were criticized as being antiquated and there were concerns about adequate power for what was a comparatively large airliner.

(Bottom) Finalized Antonov An-122P Aerobus concept

Responding to the official critique, the Antonov OKB heavily revised their An-122P design. Most obvious was a new, single vertical tail based on that of the pending An-124. Powerplants were changed from four low-bypass turbofans to two high-bypass engines. Initially, the high-bypass turbofans being considered were Rolls-Royce RB211s but the British government repeatedly declined export permission. [1] The final choice for the high-bypass engines was therefore the new D-18T turbofans then being developed by OKB-478 (Ivchenko Lotarev) for the An-124 transport.

A less apparent change in the finalized An-122P concept was a modest forward fuselage stretch to increase passenger capacity (while addressing c/g issues) and a revised nose profile (to further reduce the Aerobus submission's resemblance to the An-22 military transport). Unfortunately for the Antonov OKB, the September 1968 revisions to the Aerobus program now favoured a somewhat smaller airframe for the new Sredniy Aerobus.

_________________________

[1] RW Rolls-Royce made at least two applications for export of RB211 variants to the Soviet Union.

_________________________
Under investigation by the Committee of State Sanctioned Modelling, Alternative History and Tractor Carburettor Production for decadent counterrevolutionary behaviour.

Offline AXOR

  • Our returned Monkey Box man
Re: Аэробус - the Soviet Aerobus Program
« Reply #1 on: June 06, 2017, 06:41:51 AM »
This is so awesome !!!
Alex

Offline GTX_Admin

  • Evil Administrator bent on taking over the Universe!
  • Administrator - Yep, I'm the one to blame for this place.
  • Whiffing Demi-God!
    • Beyond the Sprues
Re: Аэробус - the Soviet Aerobus Program
« Reply #2 on: June 07, 2017, 01:58:45 AM »
 :)
All hail the God of Frustration!!!

Offline Tophe

  • He sees things in double...
  • twin-boom & asymmetric fan
    • my models
Re: Аэробус - the Soviet Aerobus Program
« Reply #3 on: June 07, 2017, 11:29:41 PM »
Me and my son (he is a fan of double-deck airliner) do love your Aeroboos, thanks! :-*

Offline apophenia

  • Suffered two full days of rapid-fire hallucinations and yet had not a single usuable whif concept in the lot !?!
  • Patterns? What patterns?
Re: Аэробус - the Soviet Aerobus Program
« Reply #4 on: June 08, 2017, 02:38:31 AM »
Cheers folks!  Tophe: One more double-decker to come  ;)

Ilyushin OKB and the Aerobus Program (Part One)

Assuming that most BtS members know almost as little as I did about the Soviet Aerobus program, a brief digression into the RW history seems warranted here. The Ilyushin Design Bureau (OKB-240) undertook a series of design studies which ultimately resulted in the IL-86. The original OKB-240 take on Aerobus was a series of enlarged IL-62 'Ivanushka' derivatives -- including one with a 6.70 m fuselage stretch and another as a double-decker with an upper lobe added to the fuselage.

Also proposed was a straightforward passenger adaptation of the IL-76 cargo jet. This too was to feature double decks - now with drop-down stairs at the rear (fitting with the Aerobus program approach of having passengers load their own luggage). This concept was then refined by fitting an entirely new, 'wide body' fuselage to the IL-76 wings, Soloviev D-30T powerplants, and tailplane.

(Top) Ilyushin 'wide body' Aerobus design study based on the IL-76 wing and engines.

Further OKB-240 design studies fitted a similar 'wide body' fuselage with a low wing and four, paired fuselage-mounted Kuznetsov NK-86 engines similar to the IL-62's arrangement. Other than the powerplants, commonality between this new concept and the in-service IL-62 would be minimal.

(Bottom) Ilyushin 'wide body' IL-62 derivative (one of many such design studies)

The rear-engine arrangement fit with the preferences of Soviet authorities (which did not favour 'Western' approaches like aero-elastic wings with podded engines). The 'wide body' fuselage matched another desire of the aparatchiks - to rival the anticipated Western Lockheed L1011 and McDonnell-Douglas DC-10. However, for the no-frills Aerobus approach, further improvements were possible.

____________________________
Under investigation by the Committee of State Sanctioned Modelling, Alternative History and Tractor Carburettor Production for decadent counterrevolutionary behaviour.

Offline apophenia

  • Suffered two full days of rapid-fire hallucinations and yet had not a single usuable whif concept in the lot !?!
  • Patterns? What patterns?
Re: Аэробус - the Soviet Aerobus Program
« Reply #5 on: June 08, 2017, 02:45:08 AM »

Ilyushin OKB and the Aerobus Program (Part Two)

The next OKB-240 design study reduced the Aerobus' fuselage length while adding a partial lower deck in the forward fuselage. In most other respects, this design study remained unchanged from its immediate predecessor.

(Top) Ilyushin 'wide body' IL-62 derivative with partial double-deck arrangement

At this point, in the RW, OKB-240 changed tack and adopted separately-podded, wing-mounted engines. With this came a more conventional tail arrangement and a return to a single-deck arrangement. Boring!  The result was the IL-86 that we all know. So, enough with the RW ...

In my whif version, OKB-240 takes its cue from Antonov and adapt Lotarev D-18T high-bypass turbofans [1] to its original, rear-engined, T-tailled Aerobus proposal. In the original scheme, 4 x 28,665 lbf Kuznetsov NK-86 low-bypass engines were mounted in pairs on either fuselage side. Compared to the NK-86-powered study, the fuselage was slightly shortened and the under-floor 'steerage' class seating eliminated. As a result of this airframe lightening, the revised design required only two D-18T engines of 51,600 lbf each -- one engine mounted on each side of the fuselage. [2]

(Bottom) Ilyushin IL-86A -- a 'wide body' IL-62 derivative with single deck and twin Lotarev D-18T turbofans

In March 1971, the resulting IL-86A design was chosen by the Soviet Government to fulfill its Sredniy Aerobus requirement. Full-scale production of the IL-86A was ordered in October 1972 and by, early 1980, Gosplan/Gossnab had arranged for delivery of this new Sredniy Aerobus to Aeroflot.

____________________________

[1] The D-18T was, in effect, a scaled-up Lotarev D-36 although OKB-478 actually designed the two engine types in tandem.

[2] Export IL-86Es could be fitted with alternative engines, the British Rolls-Royce RB.211-22B.

____________________________
Under investigation by the Committee of State Sanctioned Modelling, Alternative History and Tractor Carburettor Production for decadent counterrevolutionary behaviour.

Offline apophenia

  • Suffered two full days of rapid-fire hallucinations and yet had not a single usuable whif concept in the lot !?!
  • Patterns? What patterns?
Re: Аэробус - the Soviet Aerobus Program
« Reply #6 on: June 10, 2017, 07:09:20 AM »

'PA' -- The Prigorodnyy Aerobus component of the Aerobus Program

The second component of the Soviet Aerobus program was for a smaller Prigorodnyy Aerobus ('PA') or Commuter Aerobus. This was to be a much smaller, shorter-range airliner. The 'PA' would have a lower passenger capacity but be capable of operating from shorter, rougher airfields than the larger Sredniy Aerobus ('SA') or Medium(-range) Aerobus.

Antonov OKB and the Prigorodnyy Aerobus

Having unsuccessfully submitted its An-122 for the SA contest, the Antonov OKB turned its attention to Prigorodnyy Aerobus concepts. Work had already begun on a potential replacement for Aeroflot's in-service Tupolev Tu-134 fleet. The Tu-134 was designed to carry 80 passengers but, on Soviet routes, often few 'light'. Antonov proposed a somewhat smaller aircraft carrying only 64 to 73 passengers (depending upon seat configuration).

Although aimed specifically at Tu-134 replacement the Antonov OKB also believed that their An-60 concept fit the 'PA' component of the Aerobus program. The Prigorodnyy Aerobus concept would carry 73 passengers. Its layout featured high-mounted swept wings and a T-tail (also with swept surfaces. Two Lotarev D-36 high-bypass turbofans were pylon-mounted beneath the wings.

(Top) Primered 'PA' candidate - prototype Antonov An-60 as first rolled-out.

The Antonov OKB's An-60 concept was sufficiently promising to order a demonstrator prototype. Testing showed the An-60 to be lively performer in the air which also handled the roughest of ground upon landing. The latter resulted in a somewhat heavier airframe which increased the An-60's operating costs compared with the rival Yak-142 concept.

In the end, the An-60 was rejected as a Prigorodnyy Aerobus candidate. However, the design work was not wasted. The An-60 had been designed in tandem with a more successful light military transport. [1]

Yakovlev OKB and the Prigorodnyy Aerobus

The Yakovlev OKB had also designed a Tu-134 replacement but took a different approach to Antonov. To improve operating costs, Yakovlev went bigger with its 100-120-seat Yak-42. [2] The resulting airliner was somewhat large to be a Prigorodnyy Aerobus candidate. The Yakovlev OKB's solution was a redesign turning their trimotor Yak-42 into the smaller-capacity, twin-jet Yak-142.

The Yak-142 could not hope to match the An-60's rough field abilities but its lighter structure offered superior operating costs. The Yak-142's two rear-mounted Lotarev D-36Ts were also better protected from foreign object damage than the Antonov's underslung pods. To this could be added the benefits of maximum commonality with the airframe and systems of the in-service Yak-42.

(Bottom) In-service Yak-142 twin-jet Prigorodnyy Aerobus in Aeroflot livery

____________________

[1] That aircraft incorporated a rear ramp but, more radically, it also featured high-mounted engines to produce upper-surface blowing. That tactical transport later entered V-VS service as the An-72.

[2] The tri-jet Yak-42 was originally intended to replace the Tu-134 jet as well as various smaller Aeroflot turboprop types. It was later realized that the Yak-42 could replace the Ilyushin IL-18 but a smaller design would make a better replacement for Antonov An-24 and An-26 airliners.
____________________
Under investigation by the Committee of State Sanctioned Modelling, Alternative History and Tractor Carburettor Production for decadent counterrevolutionary behaviour.

Offline Brian da Basher

  • He has an unnatural attraction to Spats...and a growing fascination with airships!
  • Global Moderator
  • Hulk smash, Brian bash
Re: Аэробус - the Soviet Aerobus Program
« Reply #7 on: June 11, 2017, 02:31:53 AM »
Your airliners are a credit to the ingenuity of the Great Soviet Collective, comrade Apophenia!

An Order of the Red Banner with Gold Star, Hammer & Sickle and a 1,000 liters of vodka for your amazing efforts!

Brian da Basherski

P.S. Hard to pick a favorite, but I especially like the shoulder-wing pre IL-86 design study! Great stuff all 'round!

Offline pigflyer

  • If reality is real, give me whatif. Really?
Re: Аэробус - the Soviet Aerobus Program
« Reply #8 on: June 11, 2017, 09:46:10 PM »
Superb work Comrade, your work shines out across the motherland like a beacon. (You are licenced for beacons Comrade, are you not?)

 ;)
If I don't plan it, it can't go wrong!

If it's great, I did it. If it's naff, I found it.

Offline apophenia

  • Suffered two full days of rapid-fire hallucinations and yet had not a single usuable whif concept in the lot !?!
  • Patterns? What patterns?
Re: Аэробус - the Soviet Aerobus Program
« Reply #9 on: June 14, 2017, 06:28:30 AM »
Thanks guys! I know that the An-60 has an extra helping of ugly but I really enjoyed doing that patchy primer finish  :D
Under investigation by the Committee of State Sanctioned Modelling, Alternative History and Tractor Carburettor Production for decadent counterrevolutionary behaviour.