Ilyushin Il-86

Development


Background


In the mid-1960s, the [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] planned airliners seating twice the then-maximum of some 200 passengers.

They were known as airbuses at the time. The Soviet leadership wanted to match them with an aerobus ([Vous devez être inscrit et connecté pour voir ce lien]: аэробус). Alongside the propaganda motive, the USSR genuinely needed an aerobus. Aeroflot expected over 100 million passengers a year within a decade (the 100th million annual passenger was indeed carried on 29 December 1976.)

First to respond was [Vous devez être inscrit et connecté pour voir ce lien], the bureau led by [Vous devez être inscrit et connecté pour voir ce lien]. It proposed a 724-seat version of the [Vous devez être inscrit et connecté pour voir ce lien] airlifter.

The project was promoted until 1969, ultimately with a 605-passenger interior (383 on the upper deck and 223 on the lower).
It did not go ahead due to fears that it would be old-fashioned and because the [Vous devez être inscrit et connecté pour voir ce lien]-based bureau was close to the deposed [Vous devez être inscrit et connecté pour voir ce lien].

Concept


Many airports had terminals too small for "aerobuses".

In the West, the solution to this involved constructing greater airport capacity.
^{[Vous devez être inscrit et connecté pour voir ce lien]}
By contrast, Soviet aviation research institutes addressed ways of increasing passenger throughput without the need for additional airport capacity.

Many Soviet airports also had surfaces too weak for "aerobuses".

The Soviet solution again favoured adapting aircraft to existing conditions, rather than reconstructing airports.

The aerobus thus had to match the ground loadings of existing airliners.

This called for complex multi-wheel [Vous devez être inscrit et connecté pour voir ce lien].

The "Luggage at hand" system


The Soviet solution to the airport capacity issue involved passengers loading and unloading their own luggage into and from the aircraft.

This was eventually called "the luggage at hand system" ([Vous devez être inscrit et connecté pour voir ce lien]: "система «багаж с собой»"; [Vous devez être inscrit et connecté pour voir ce lien]: "sistyema bagazh s soboy").

Soviet aviation journalist Kim Bakshmi described it (at its ultimate) thus: "One arrives five minutes prior to departure, buys oneself a ticket on board the aircraft, hangs one's coat next to the seat and places one's bag or suitcase nearby."

Taking suitcases into the cabin, as in trains, was studied, but necessitated a 3 m fuselage extension with a 350-seat capacity.

To avoid this, passengers were to deposit their luggage in underfloor compartments as they entered the airliner.

Ideas similar to the "luggage at hand system" were briefly addressed in the West.

[Vous devez être inscrit et connecté pour voir ce lien] studied such an arrangement in the mid-1970s,. [Vous devez être inscrit et connecté pour voir ce lien] implemented it into the [Vous devez être inscrit et connecté pour voir ce lien] in 1973 at the request of [Vous devez être inscrit et connecté pour voir ce lien] (who used the baggage compartment as an entertainment lounge) and possibly also to suit potential Soviet buyers (see below).

Formal aerobus programme launch

In October 1967, the Soviet government approved a Ministry of Civil Aviation (Aeroflot) specification for an aerobus.

This called for 350 seats and a range of 3,600 km (1,900 [Vous devez être inscrit et connecté pour voir ce lien]) with a 40-[Vous devez être inscrit et connecté pour voir ce lien] payload or 5,800 km/3,100 nmi with seats taken but no freight.

The airliner had to operate from smaller airports (classified as Klass "B" and "V" [Russian: класс "Б", "В"] or "Class B/C" by the Soviets) 2,600 m (8,500 [Vous devez être inscrit et connecté pour voir ce lien]) runways.

In the second half of the 1960s, OKB-240 (as the Ilyushin bureau was formally known) was restoring positions lost (with Yakovlev, in favour of Tupolev and Antonov) during the Khrushchev era and was well placed to secure design of the aerobus.

When the Soviet cabinet's defence industry committee promoted the Aeroflot specification on September 8, 1969 to a preliminary project, (Russian: аванпроект; transliterated: avanproyekt), it entrusted it to Ilyushin.

The bureau received specific operational requirements for the aerobus on February 22, 1970.

In developing the concept which had been agreed, Ilyushin faced four challenges: configuration (layout or "shape"), powerplant, automation (avionics) and manufacturing capacity.

Conceptual development


Ilyushin began work on the aerobus in late 1969, initially by assessing the development potential of existing aircraft.

An enlarged [Vous devez être inscrit et connecté pour voir ce lien] (the Il-62-250) would have had a 30-tonne payload, 259 seats and a 6.8 metre/22 ft longer [Vous devez être inscrit et connecté pour voir ce lien]: a virtual [Vous devez être inscrit et connecté pour voir ce lien] of the [Vous devez être inscrit et connecté pour voir ce lien] "Super Sixty" series.

Other proposed Il-62 modifications involved double-deck and "two fuselages side-by-side" developments.

There was also a project to "civilianise" the [Vous devez être inscrit et connecté pour voir ce lien].

From March 1970 the bureau developed all-new designs under the Il-86 designation.

Instead of the "[Vous devez être inscrit et connecté pour voir ce lien]" approach of the Il-62, these designs were to have powered controls, complex [Vous devez être inscrit et connecté pour voir ce lien] and advanced automation which would reduce the number of [Vous devez être inscrit et connecté pour voir ce lien] crew.

An early avanproyekt was shown to the Soviet leadership at an exhibition of civil aviation innovations at [Vous devez être inscrit et connecté pour voir ce lien] near Moscow on May 17, 1971.^{[Vous devez être inscrit et connecté pour voir ce lien][Vous devez être inscrit et connecté pour voir ce lien]}

A scale model with the designation of "Il-86" showed the "self-loading" concept with integral boarding stairs, below-deck luggage stores, and below-deck midships [Vous devez être inscrit et connecté pour voir ce lien].

It had a twin-aisle interior with nine-abreast seating in a "3-3-3" layout.

Ilyushin considered it politic to make the interior wider than any planned airliner except the Boeing 747.

The 6.08 m (19.9 ft) fuselage diameter was partly dictated by the need to provide standing room in the underfloor luggage compartments.

It remained the second-widest airliner interior until the [Vous devez être inscrit et connecté pour voir ce lien].

On this basis, on 9 March 1972, the bureau was asked to proceed with detailed design.

The difference between the 1971 model and the eventual Il-86 was in configuration: the model had looked like an Il-62.

At that time, the Central Aero and Hydrodynamics Institute ([Vous devez être inscrit et connecté pour voir ce lien]) favoured the clean-winged, rear-engined, T-tailed configuration for airliners. The [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien]/[Vous devez être inscrit et connecté pour voir ce lien]/[Vous devez être inscrit et connecté pour voir ce lien] projects had similar configurations.

The configuration issue


The configuration of [Vous devez être inscrit et connecté pour voir ce lien] jet aircraft was a politically sensitive issue in the USSR. Aircraft designer [Vous devez être inscrit et connecté pour voir ce lien]^{[Vous devez être inscrit et connecté pour voir ce lien]}
states this of the underwing-engine US-pioneered layout which gradually became standard for jet airliners: "The configuration of the [Vous devez être inscrit et connecté pour voir ce lien], taken on strength by the [Vous devez être inscrit et connecté pour voir ce lien] ... brought forth a veritable storm of critical opinions from [Soviet] aviation scientists.

Responsible TsAGI officials and industry leaders robustly called that aircraft 'utter nonsense' (similar opinions were
expressed of the Boeing 747)."

Similar controversies were known in Western aeronautical circles^{[Vous devez être inscrit et connecté pour voir ce lien]} but typified Soviet [Vous devez être inscrit et connecté pour voir ce lien] which held that problems had immutable, [Vous devez être inscrit et connecté pour voir ce lien] solutions.^{[Vous devez être inscrit et connecté pour voir ce lien]}

Ilyushin therefore had to stress that it had first in the world used podded engines suspended from pylons beneath and ahead of the wing, on the experimental [Vous devez être inscrit et connecté pour voir ce lien] four-engined jet bomber of 1946 (first use of this designation).

Having thus been presented the Il-86's ultimate configuration as indigenously Soviet, the bureau could at last show it in public in 1973, six years after publication of the aerobus specification and four years after the design assignment.

A modern six-window flightdeck followed, in place of the 18-to-20 window glazing of the [Vous devez être inscrit et connecté pour voir ce lien], Il-62 and Il-76.

Powerplant issue

The main problem facing the Il-86 project was the lack of a suitable engine.

It was never resolved. By the close of the 1960s, the USA and the [Vous devez être inscrit et connecté pour voir ce lien] had [Vous devez être inscrit et connecté pour voir ce lien] with [Vous devez être inscrit et connecté pour voir ce lien] of 4 or 5 to 1.

The first Soviet large turbofan, the [Vous devez être inscrit et connecté pour voir ce lien], did not appear before the mid-1980s.

The [Vous devez être inscrit et connecté pour voir ce lien], originally intended for the Il-86, was the most advanced Soviet civil [Vous devez être inscrit et connecté pour voir ce lien].

It had a bypass ratio of 2.4 to 1 and aerodynamic clamshell [Vous devez être inscrit et connecté pour voir ce lien].

It failed to attain the required thrust, however: "only after the lapse of three years that were spent on preparing the advanced development project did it become clear that these engines would not provide the necessary take-off performance."

The less-advanced [Vous devez être inscrit et connecté pour voir ce lien] series engine, adopted on March 26, 1975, had a bypass ratio of 1.15 to 1 and drag-inducing grilles over its cascade thrust reversers.

Both these engines had high [Vous devez être inscrit et connecté pour voir ce lien] and were [Vous devez être inscrit et connecté pour voir ce lien].

Being ultimate developments of smaller engines, they could not offer growth to future Il-86s.

Kuznetsov NK-86


[Vous devez être inscrit et connecté pour voir cette image]

Interest in foreign technology


The Soviets tried to import technology to solve the powerplant (and to an extent the avionics and manufacturing capacity) issues.

The attempts took two directions.

First was wholesale [Vous devez être inscrit et connecté pour voir ce lien] similar to the [Vous devez être inscrit et connecté pour voir ce lien] deal of the 1930s.

This would have delayed Il-86 development, since the programme would have been demoted to a reserve status.

The second direction was to import individual systems and items.

This would have speeded Il-86 development.

The fact that Il-86 development was protracted indicates that for long periods the programme was pursued as
backup insurance in case wholesale technology transfer failed.


Interest in alternative foreign aircraft

Before the [Vous devez être inscrit et connecté pour voir ce lien] had flown, a Ministry of Civil Aviation delegation visited the USA for a series of detailed sales presentations on the type lasting three days.

At the 1971 Paris Salon, Ilyushin bureau head [Vous devez être inscrit et connecté pour voir ce lien] and Boeing's [Vous devez être inscrit et connecté pour voir ce lien] are claimed to have arranged an informal technology [Vous devez être inscrit et connecté pour voir ce lien].

Over supper in a [Vous devez être inscrit et connecté pour voir ce lien] restaurant, the Soviet side is claimed to have ceded information on [Vous devez être inscrit et connecté pour voir ce lien] technology to the Americans, while the latter, "sketching on the tablecloth," ceded information on "the structural and aerodynamic amity
of the [Vous devez être inscrit et connecté pour voir ce lien] wing."

Soviet interest in buying the 747s continued until the end of [Vous devez être inscrit et connecté pour voir ce lien] in the late 1970s.

At the peak of détente, on March 11, 1974, a [Vous devez être inscrit et connecté pour voir ce lien] arrived in Moscow for three days of sales presentations and demonstrations.

The TriStar matched the Il-86 in size and performance and had development potential. Negotiations to buy 30 TriStars of the L-1011-385-250 version and licence-produce up to 100 a year in a new factory employing 80,000 people continued until mid-1976.

Any residual will to export TriStars was scotched when US President [Vous devez être inscrit et connecté pour voir ce lien] made human rights a [Vous devez être inscrit et connecté pour voir ce lien] factor.

TriStar exports would have needed [Vous devez être inscrit et connecté pour voir ce lien] clearance: the type embodied advanced technology banned from potential enemies.

In 1978, the US Department of Commerce vetoed export of 12 [Vous devez être inscrit et connecté pour voir ce lien] engines ordered by the USSR for planned long-range Il-86s.

Attempts at illicit technology acquisition


By analogy with other aircraft programmes,^{[Vous devez être inscrit et connecté pour voir ce lien]} a third direction in the efforts to acquire foreign technology may have involved illicit action along the lines of the [Vous devez être inscrit et connecté pour voir ce lien] of the [Vous devez être inscrit et connecté pour voir ce lien] from the [Vous devez être inscrit et connecté pour voir ce lien] and the copying of the [Vous devez être inscrit et connecté pour voir ce lien] jet engine as the [Vous devez être inscrit et connecté pour voir ce lien].

Oblique reference to this comes in an account of the An-124 by the then-powerplant head of the Antonov bureau, V. G. Anisyenko: "The MAP leadership wanted to have a uniform large engine also capable of civil aviation applications, such as the Il-86.
The most suitable analogue from this viewpoint was considered to be the Rolls-Royce RB.211-22.

To purchase it, in 1976 a MAP procurement party went to Great Britain, headed by engine construction deputy minister Dondukov ... Our ultimate task was to copy the [Vous devez être inscrit et connecté pour voir ce lien], for which purpose we had to buy not fewer than eight examples ... The English ... would only sell us the engine in quantities ... to power no fewer than 100 aircraft.
As a result, we did not get a sample ... "

Design, testing and certification

The design process at Ilyushin was managed by Sergey Ilyushin's successor as head of the bureau, Genrikh Novozhilov.

The timescale announced in 1973 envisaged first flight in 1976 and service entry in time for the [Vous devez être inscrit et connecté pour voir ce lien] in 1980.

The prototype flew at [Vous devez être inscrit et connecté pour voir ce lien] airfield (where Ilyushin's experimental factory was) on December 22, 1976 (Soviet airliners often flew before the close of calendar years due to the requirements of [Vous devez être inscrit et connecté pour voir ce lien]).

It was announced that the type had a patented electromagnetic pulse [Vous devez être inscrit et connecté pour voir ce lien] system. which used 500 times less energy than conventional deicers.

It is claimed that over 50 new technological processes were introduced into Soviet practice as a result of the Il-86 programme.

The initial test programme was flown by Ilyushin staff, ending two months ahead of schedule on October 20, 1978.

Other sources claim that these tests were completed on 22 September 1978.
(According to a faster schedule announced at the time of the first flight, Ilyushin tests were to have ended in time for the 60th anniversary of the October Revolution on November 7, 1977.)

In-house testing involved speeds up to Mach 0.93 and bank angles up to 11 degrees greater than specified.

Initial certification flying by pilots independent of Ilyushin ended on June 6, 1977.

State acceptance trials began on April 24, 1979 and ended on December 24, 1980.

Certification by Gosaviaregistr SSSR [the USSR State Aviation Registry] was granted under certificate number 10-86.

The Il-86 entered Aeroflot service on 26 December the same year.

The service-entry deadline of summer 1980, announced by Minister of Civil Aviation Boris Bugayev in 1977 had passed, however, and the Il-86 missed the Moscow Olympics in the summer of 1980.

Overall development of the Il-86 occupied over a decade.

The length of this period was due to the sensitivity of the airliner's configuration, problems with its powerplant, prolonged avionics development and the low priority of civil as opposed to military aircraft.

In its earlier stages, the Il-86 programme was also held back by hopes of US airliner imports.

Certificating the Il-86 to the very demanding set of Soviet and [Vous devez être inscrit et connecté pour voir ce lien] standards called NLGS-2 also delayed progress; it was the first Soviet aircraft to undergo a full certification programme since certification was introduced in the USSR in 1967 and became mandatory five years later.