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Tag Archives: Maxim Gorky

CROSSING THE T

MAXIM#1

 

The early pioneers of aviation sometimes branched out from other fields before realizing their ultimate success.  For example, Glenn Curtiss raced motorcycles and developed small engines prior to his fame in aviation.  Both Wiliam Boeing and his family were in the timber business before he founded the Boeing aircraft company.  The hero of this blog was no exception, although he achieved his success by a more indirect route.

Andrei Nickolaevich Tupolev was born in Pustomozovo, Russia in 1888.  The sixth of a family of seven children, Tupolev developed an early interest in building models and small pieces of furniture – a hobby his parents encouraged.  After his graduation from the Tver secondary school in 1908, Tupolev applied to the Moscow Imperial Technical High School (IMTU) pursuing a technical degree.  During his time at the technical school, Tupolev met Nickolai Zhukovski, who introduced the subject of aeronautics at IMTU.  Zhukovski would serve as both an instructor and a mentor to Tupolev. Perhaps Tupolev’s most significant project at IMTU was the construction of a wind tunnel, one of the first in practical use, from which to test aerodynamic designs.  Tupolev was arrested in 1911 for involvement in a subversive student organization. Though Zhukovski interceded on Tupolev’s behalf, he wasn’t successful and Tupolev was placed under house arrest, only allowed to leave to attend his father’s funeral later that year.  He was finally released in 1914 and resumed his studies, graduating in 1918 with the degree of Engineer-Mechanic.

In 1918 Zhukovski and Tupolev petitioned the Soviet government to establish an aerodynamic research organization.  In December 1918 their request was granted and the Central Aero/Hydrodynamics Institute or TsAGI was established. TsAGI grew rapidly from an initial staff of six to nearly thirty engineers and technicians by mid 1919.  In 1921 Tupolev was elected by the staff at TsAGI to be Zhukovski’s deputy or Comrade To The Director.  The following year he began work on his first aircraft, designated the ANT 1, using Tupolev’s initials for the name. Because he advocated the use of light metals in aircraft, such as duraluminium, pioneered by Junkers in Germany, Tupolev met with opposition from the timber industry, promoting the construction of wooden aircraft.  Although he won the battle for an all-metal aircraft, the ANT 1 was built of mixed metal and wood.  It was a single seat cantilever monoplane, with a 25′ wingspan.  The ANT 1 first flew in late 1923 and was a successful design.  In 1927 the ANT 2, the Soviet Union’s first all-metal plane flew, proving both the durability and practicality of light metal construction.  The ANT 2 was powered by an air cooled 100 hp. Bristol Jupiter engine and could accommodate two passengers in the cabin with an open cockpit for the pilot.

In the 1930′s Tupolev traveled to Germany, France, Britain and the United States to gain insight into the aircraft technologies of those nations.  He encouraged the Soviet government to purchase a license to manufacture Wright Cyclone engines, which were the basis for a series of Soviet built air-cooled engines, as well as  the liquid-cooled Hispano Suiza engine from France. Tupolev’s design bureau produced a number of large scale aircraft, such as the ANT 20, named after the famous Russian poet Maxim Gorky.  The ANT 20 was an extremely big plane for its day, having a fuselage 107′ long with a wingspan of 207′.  The Maxim Gorky was powered by eight engines, six in the wing and two above the fuselage.  The passenger compartment was subdivided into four cabin areas.  The ANT 20 first flew in 1934 and made several foreign tours, of great propaganda value to the Soviet state.  However, the Maxim Gorky crashed in May 1935 as a result of a mid air collision with a fighter performing aerobatic maneuvers during a Moscow airshow. Tupolev’s next major effort was the development of the ANT 25. The ANT 25 was first proposed in 1931 as a long range bomber.  The 25 plane was somewhat smaller than the Maxim Gorky, with a 44′ long fuselage coupled with a 112′ wingspan.  It had a crew of three: pilot, copilot, and a navigator who doubled as a radio operator.  The long tapered wings of the plane contributed to its range by storing its fuel tanks, which accounted for 52 % of its take off weight.  After several test flights in 1934-36, two ANT 25s made transpolar flights from Moscow to Pearson Field, Oregon and San Jacinto, California in June 1937.  Both planes had enough fuel to reach Panama, but were denied permission by the Mexican government to overfly its territory.

The World War II era was a difficult one for both Tupolev and his design bureau.  He was arrested in 1937 for passing aviation secrets to foreign governments, a charge which was totally baseless.  Both he and his staff were imprisoned until released in July 1941.  Tupolev and his team worked round the clock designing and improving Soviet aircraft for the demands of war. In 1945 Tupolev was given the demanding task of reverse engineering the Boeing B-29 Superfortress. Though the Soviet Union was not yet at war with Japan, four of the Boeing planes could not make it back to their Marianas bases and were forced to land near Vladivostok, on the Soviet Pacific coast.  Stalin ordered three of the planes sent to Moscow with the fourth unit retained for quality control purposes.  Tupolev was to have direct control of all aspects of engineering and production.  Any requests made by his staff were given top priority, which greatly reduced production time.  In just 20 months, the first Soviet B-29 (TU-4) flew above the 1947 May Day parade, to the astonishment of western observers.

Tupolev went on to produce a number of other Soviet aircraft, such as the TU-16 Badger, the Soviet Union’s first major jet bomber, the TU-104 jetliner, a civil variant of the Badger, as well as the TU-95 Bear, the world’s only turboprop bomber. Tupolev’s crowning achievement came in 1968, when, as promised, his design bureau flew the worlds first supersonic transport (SST) on December 31 of that year – some two months ahead of the Concorde.  Though Tupolev experienced many hardships throughout his life, his dedication to the field of aviation produced some of the worlds premier aircraft.

TU-144

 

This blog is the third of a series about the heroes of aviation.

 

 

 

 

FLY BY WIRE

FBW#1

 

 

Ever since powered flight was first achieved by Wilbur and Orville Wright in 1903, the aviation community has sought both safer and more efficient methods of aircraft flight control.  During the course of this blog, we will trace the development of fly by wire control systems from the basic electrical controls of the 1930s to the enhanced computerized systems of today.

For about thirty years after the Wright Brothers first flight, pilots controlled an aircraft by direct force, by moving control wheels, sticks and rudder pedals linked to cables and pushrods , which pivoted control surfaces on the wings and tails. However, as engine power, speeds and aircraft weight increased, more force was required to effectively direct aircraft control surfaces.   Mechanical and hydraulic control systems were introduced to compensate for the increased power needs upon control surfaces.  Such systems were relatively heavy and necessitated a careful routing of flight control cables through the plane by systems of cranks, pulleys, hydraulic pipes and tension cables.  Although the mechanical and hydraulic systems provided a substantial boost to aircraft controls, they required multiple backup systems in the event of failures, further increasing weight in the design of the aircraft.  Another problem of the hydro/mechanical systems was their insensitivity to outside aerodynamic forces such as spinning, stalling and vibrations during flight.

Electrical transmission to a plane’s control surfaces was first accomplished in 1934 on the Soviet ANT-20, the Maxim Gorky.  The series of mechanical and hydraulic connections were replaced with electrical ones.  This was an extremely large aircraft for its day and the electrical connections worked flawlessly until the collision of the aircraft the following year, proving the potential of electrical flight control.  However, a dedicated electronic signal avionics control system was not tested until 1958 on the Avro Canada CF-105 Arrow.  Ironically, the first vehicle to utilize an electronic flight control system without mechanical or hydraulic backup was the Lunar Landing Research Vehicle or LLRV, which flew successfully in 1964 as part of the Apollo moon program.

A fly by wire control system is a computer system, which monitors pilot control commands and related factors such as altitude, airspeed and angle-of- attack.  The FBW system then relays these pilot inputs to the flight control surfaces in order to keep the aircraft within its designated flight envelope, or safe flight parameters of the aircraft at various speeds, altitudes and other flight conditions.  The fly by wire computer employs electrical signal inputs to create electrical signal outputs which affect the flight control surfaces to produce the desired aircraft attitude.  FBW computers utilize both analog and digital processing with digital units first appearing in quantity in the late 1970s.  The essential difference between digital and analog units lies in how they process information.  Analog computers work in a continuous cycle in which data can accept an infinite set of values, resulting in no loss of data.  The primary limitation of analog units is the time required to initially configure the hardware to the aircraft, in addition to the difficulty of upgrading existing hardware.  Digital systems operate in a designated time environment, in which values are finite.  Any loss of data is supplemented by relatively high resolution and sampling rates, which minimize data loss.  Upgrading a digital unit is merely a matter of downloading current software, achieving a smooth transition coupled with reduced software and maintenance costs.  The flight control systems offer both redundant computer processing and circuitry in case of failure of the primary unit.

Fly by wire technology offers a number of advantages.  Aircraft weight is greatly reduced since mechanical and hydraulic linkages are no longer necessary.  Safety is enhanced due to both redundancy of electrical circuits as well as a quick response and processing time from the FBW unit, supplanting the skill of the pilot.  Fly by wire systems benefit military aviation by allowing engineers the latitude to design an aircraft which may be inherently unstable, but yet be able to attain superior maneuverability under the parameters of the fly by wire computer.  FBW systems require fewer parts and less fuel usage while providing more comfort for passengers because of more precise handling characteristics.  Fly by wire control systems provide for greater safety by establishing control parameters within the capability of the plane with digital units compatible with the entire range of aircraft sensors.