Sofia Airport in 1979
Traveling back in time
By Jan Koppen
Sofia Airport, sometimes also called Sofia-Vrazhdebna Airport, is the main airport of Bulgaria. The airport was initially built in the late 1930s on a site 10 km distant from the geographical centre of Sofia. During the Second World War, the facilities were used by the military. The passenger terminal (now Terminal 1) on the south side was completed during the Second World War in the manner of a then-modern European railway terminus to designs by the architect Ivan Marangozov. The terminal had substantially reached its capacity by the later 1960s and was subjected to a number of refurbishments and extensions beginning in the spring of 1968. In 1975, a new international arrivals handling extension was opened.
Balkan Bulgarian Airlines was Bulgaria's government-owned flag carrier between 1947 and 2002. During the 1970s, the airliner became a significant European carrier. The company encountered financial instability following the fall of communism in Central and Eastern Europe. Despite managing to continue operations, following the start of the 21st century and a controversial privatization, it declared bankruptcy in 2002. Balkan was liquidated in late October 2002. Bulgaria Air was appointed Balkan's successor in December 2002.
Balkan Bulgarian Airlines was Bulgaria's government-owned flag carrier between 1947 and 2002. During the 1970s, the airliner became a significant European carrier. The company encountered financial instability following the fall of communism in Central and Eastern Europe. Despite managing to continue operations, following the start of the 21st century and a controversial privatization, it declared bankruptcy in 2002. Balkan was liquidated in late October 2002. Bulgaria Air was appointed Balkan's successor in December 2002.
"Antonov An-24B LZ-AND and her forerunner the Ilyushin IL-14, made a wonderful day at the Sofia terminal viewing terrace".
Note; - The car in the picture looks like a Moskvitch-2137 station wagon.
"It was a lovely day over Sofia, clear as a bell, while LZ-BTA taxies into her base at Sofia-Vrazhdebna".
The Tu-154 first flew on 4 October 1968. The first deliveries to Aeroflot were in 1970 with freight (mail) services beginning in May 1971 and passenger services in February 1972. There was still limited production of the 154M model as of January 2009, despite previous announcements of the end of production in 2006. The last serial Tu-154 was delivered to the Russian Defense Ministry on 19 February 2013. 1025 Tu-154s have been built, 214 of which are still in service as of 14 December 2009. In January 2013 the Aviakor factory announced that it was about to deliver a new Tu-154M to the Russian Ministry of Defense equipped with upgraded avionics, a VIP interior and a communications suite. The factory has 4 unfinished hulls in its inventory which can be completed if new orders are received.
The Tu-154 is powered by three rear-mounted low-bypass turbofan engines arranged similarly to those of the Boeing 727, but it is slightly larger than its American counterpart. Both the 727 and the Tu-154 use an S-duct for the middle (Number 2) engine. The original model was equipped with Kuznetsov NK-8-2 engines, which were replaced with Soloviev D-30KU-154 in the Tu-154M. All Tu-154 aircraft models have a relatively high thrust-to-weight-ratio which gave excellent performance, at the expense of poorer fuel efficiency. This became an important factor in later decades as fuel costs grew.
The flight deck is fitted with conventional dual yoke control columns. Flight control surfaces are hydraulically operated. The cabin of the Tu-154, although of the same six-abreast seating layout, gives the impression of an oval interior, with a lower ceiling than is common on Boeing and Airbus airliners. The passenger cabin accommodates 128 passengers in a two-class layout and 164 passengers in single-class layout, and up to 180 passengers in high-density layout. The layout can be modified to what is called a winter version where some seats are taken out and a wardrobe is installed for passenger coats. The passenger doors are smaller than on its Boeing and Airbus counterparts. Luggage space in the overhead compartments is very limited.
Like the Tupolev Tu-134, the Tu-154 has a wing swept back at 35° at the quarter-chord line. The British Hawker Siddeley Trident has the same sweepback angle, while the Boeing 727 has a slightly smaller sweepback angle of 32°. The wing also has anhedral (downward sweep) which is a distinguishing feature of Russian low-wing airliners designed during this era. Most Western low-wing airliners such as the contemporary Boeing 727 have dihedral (upward sweep). The anhedral means that Russian airliners have poor lateral stability compared to their Western counterparts, but also have weaker dutch roll tendencies.
Considerably heavier than its predecessor Soviet-built airliner the Ilyushin Il-18, the Tu-154 was equipped with an oversized landing gear to reduce ground load, enabling it to operate from the same runways. The aircraft has two six-wheel main bogies fitted with large low-pressure tires that retract into pods extending from the trailing edges of the wings (a common Tupolev feature), plus a two-wheel nose gear unit. Soft oleo struts (shock absorbers) provide a much smoother ride on bumpy airfields than most airliners, which only very rarely operate on such poor surfaces.
The original requirement was to have a three-person flight crew – captain, first officer and flight engineer – as opposed to 4/5-person crew on other Soviet airliners. It became evident that a fourth crew member, a navigator, was still needed, and a seat was added on production aircraft, although his workstation was compromised due to the limitations of the original design. Navigators are no longer trained and this profession will become obsolete with the retirement of older Soviet-era planes.
Note; - The easiest way to tell the A and B model from the base model is by looking at the spike at the junction of the fin and tail; this is a fat bullet on the A model rather than a slender spike on the base model.
The Tu-154 is powered by three rear-mounted low-bypass turbofan engines arranged similarly to those of the Boeing 727, but it is slightly larger than its American counterpart. Both the 727 and the Tu-154 use an S-duct for the middle (Number 2) engine. The original model was equipped with Kuznetsov NK-8-2 engines, which were replaced with Soloviev D-30KU-154 in the Tu-154M. All Tu-154 aircraft models have a relatively high thrust-to-weight-ratio which gave excellent performance, at the expense of poorer fuel efficiency. This became an important factor in later decades as fuel costs grew.
The flight deck is fitted with conventional dual yoke control columns. Flight control surfaces are hydraulically operated. The cabin of the Tu-154, although of the same six-abreast seating layout, gives the impression of an oval interior, with a lower ceiling than is common on Boeing and Airbus airliners. The passenger cabin accommodates 128 passengers in a two-class layout and 164 passengers in single-class layout, and up to 180 passengers in high-density layout. The layout can be modified to what is called a winter version where some seats are taken out and a wardrobe is installed for passenger coats. The passenger doors are smaller than on its Boeing and Airbus counterparts. Luggage space in the overhead compartments is very limited.
Like the Tupolev Tu-134, the Tu-154 has a wing swept back at 35° at the quarter-chord line. The British Hawker Siddeley Trident has the same sweepback angle, while the Boeing 727 has a slightly smaller sweepback angle of 32°. The wing also has anhedral (downward sweep) which is a distinguishing feature of Russian low-wing airliners designed during this era. Most Western low-wing airliners such as the contemporary Boeing 727 have dihedral (upward sweep). The anhedral means that Russian airliners have poor lateral stability compared to their Western counterparts, but also have weaker dutch roll tendencies.
Considerably heavier than its predecessor Soviet-built airliner the Ilyushin Il-18, the Tu-154 was equipped with an oversized landing gear to reduce ground load, enabling it to operate from the same runways. The aircraft has two six-wheel main bogies fitted with large low-pressure tires that retract into pods extending from the trailing edges of the wings (a common Tupolev feature), plus a two-wheel nose gear unit. Soft oleo struts (shock absorbers) provide a much smoother ride on bumpy airfields than most airliners, which only very rarely operate on such poor surfaces.
The original requirement was to have a three-person flight crew – captain, first officer and flight engineer – as opposed to 4/5-person crew on other Soviet airliners. It became evident that a fourth crew member, a navigator, was still needed, and a seat was added on production aircraft, although his workstation was compromised due to the limitations of the original design. Navigators are no longer trained and this profession will become obsolete with the retirement of older Soviet-era planes.
Note; - The easiest way to tell the A and B model from the base model is by looking at the spike at the junction of the fin and tail; this is a fat bullet on the A model rather than a slender spike on the base model.
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LZ-BTA. This 1972 built Tupolev Tu-154 has spent its entire life with Balkan Bulgarian flying passenger’s services between the various European capital and its Sofia base. She was withdrawn from use in late -90's and its forward section is in use as cabin trainer in a building on the north side Sofia Airport.
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A dismantled LZ-BTA plus several NK-8 turbofans.
Photo: Michal Petrykowski, Sofia, 2007. |
"The starboard engine of this pristine Balkan Bulgarian Tupolev Tu-154B comes under scrutiny during a turnaround check at a sunlit Sofia tarmac in July, 1979".
This Tupolev Tu-154B rolled-off the Aviakor Samara production-line in 1974 and was delivered new to Balkan Bulgarian as LZ-BTF. Late 1998 she was withdrawn from use at Sofia.
The Tupolev Tu-154 production started in 1970, while first passenger flight was performed at 9 February 1972. Powered by Kuznetsov NK-8-2 turbofans, it carried 164 passengers. About 42 were built. The Tu-154A was the first upgraded version of the original Tu-154 and was in production since 1974. Added were; - center-section fuel tanks, more emergency exits, while engines were upgraded to higher-thrust Kuznetsov NK-8-2U. Other upgrades include automatic flaps/slats and stabilizer controls and modified avionics. Max. take-off weight – 94,000 kg (207,235 lb). The easiest way to tell the A and B model from the base model is by looking at the spike at the junction of the fin and tail; this is a fat bullet on the A model rather than a slender spike on the base model.
The Kuznetsov Design Bureau (OKB-276) was a Soviet design bureau for aircraft engines, administrated by Nikolai Dmitriyevich Kuznetsov.
Kuznetsov produced the Kuznetsov NK-8 turbofan engine in the 90 kN (20,000 lbf) class that powered the Ilyushin Il-62 and Tupolev Tu-154 airliners. Early versions of the Tu-154 could not be modified to meet the current Stage III noise regulations and were banned from flying where those regulations are in force, such as European Union.
This Tupolev Tu-154B rolled-off the Aviakor Samara production-line in 1974 and was delivered new to Balkan Bulgarian as LZ-BTF. Late 1998 she was withdrawn from use at Sofia.
The Tupolev Tu-154 production started in 1970, while first passenger flight was performed at 9 February 1972. Powered by Kuznetsov NK-8-2 turbofans, it carried 164 passengers. About 42 were built. The Tu-154A was the first upgraded version of the original Tu-154 and was in production since 1974. Added were; - center-section fuel tanks, more emergency exits, while engines were upgraded to higher-thrust Kuznetsov NK-8-2U. Other upgrades include automatic flaps/slats and stabilizer controls and modified avionics. Max. take-off weight – 94,000 kg (207,235 lb). The easiest way to tell the A and B model from the base model is by looking at the spike at the junction of the fin and tail; this is a fat bullet on the A model rather than a slender spike on the base model.
The Kuznetsov Design Bureau (OKB-276) was a Soviet design bureau for aircraft engines, administrated by Nikolai Dmitriyevich Kuznetsov.
Kuznetsov produced the Kuznetsov NK-8 turbofan engine in the 90 kN (20,000 lbf) class that powered the Ilyushin Il-62 and Tupolev Tu-154 airliners. Early versions of the Tu-154 could not be modified to meet the current Stage III noise regulations and were banned from flying where those regulations are in force, such as European Union.
"A classic early Jet Liner is this Balkan Bulgarian Airlines Tupolev Tu-134A. I photographed her at the Sofia ramp on July 23, 1979".
Tupolev Tu-134A LZ-TUR, was manufactured in 1974 and delivered new to Balkan Bulgarian Airlines. After 10 year of faithful service fate hit a blow. January 10, 1984 when she crashed on an international flight from Berlin Schönefeld. While on approach to Sofia-Vrazhdebna in heavy snow, the crew failed to make visual contact with the ground as they descended below decision altitude. The crew attempted to overshoot for an altitude of 80 to 100 meters (260 to 330 ft.), but the aircraft hit a power line and crashed 4 km (2.5 mi) from the runway into a forest. The aircraft was destroyed with no survivors.
The Tupolev Tu-134 (NATO reporting name: Crusty) is a twin-engined airliner built in the Soviet Union from 1966 to 1984. The original version featured a glazed-nose design and, like certain other Russian airliners (including its sister model the Tu-154), it can operate from unpaved airfields.
Following the introduction of engines mounted on pylons on the rear fuselage by the French Sud Aviation Caravelle, airliner manufacturers around the world rushed to adopt the new layout. Its advantages included clean wing airflow without disruption by nacelles or pylons and decreased cabin noise. At the same time, placing heavy engines that far back created challenges with the location of the center of gravity in relation to the center of lift, which was at the wings. To make room for the engines, the tailplanes had to be relocated to the tail fin, which had to be stronger and therefore heavier, further compounding the tail-heavy arrangement. During a 1960 visit to France, Soviet leader Nikita Khrushchev was so impressed by the quiet cabin of the Caravelle, that on 1 August 1960 the Tupolev OKB received an official directive to create the Tu-124A with a similar engine arrangement.
Design curiosities of the Tu-134 included a sharp wing sweepback of 35 degrees, compared to 25–28 degrees in its counterparts. The engines on early production Tu-134s lacked thrust reversers, which made the aircraft one of the few airliners to use a brake parachute for landing. The majority of onboard electronics operated on direct current. The lineage of early Soviet airliners could be traced directly to the Tupolev Tu-16 strategic bomber, and the Tu-134 carried over the glass nose for the navigator and the landing gear fitted with low-pressure tires to permit operation from unpaved airfields.
Serial production began in 1966 at the Kharkov Aviation Production Association, and production of the Tu-124 was discontinued. The Tu-134 was designed for short-haul lines with low passenger traffic. Originally the aircraft had 56 seats in a single class configuration, or 50 seats in a two-class configuration. In 1968, Tupolev began work on an improved Tu-134 variant with a 72-seat capacity. The fuselage received a 2.1-meter (6 ft 11 in) plug for greater passenger capacity and an auxiliary power unit in the tail. As a result, the maximum range was reduced from 3,100 kilometers to 2,770 kilometers. The upgraded D-30 engines now featured thrust reversers, replacing the parachute. The first Tu-134A, converted from a production Tu-134, flew on 22 April 1969. The first airline flight was on 9 November 1970. An upgraded version, the Tu-134B began production in 1980, with the navigator position abandoned, and seating capacity increased to 96 seats. Efforts subsequently began to develop a Tu-134D with increased engine thrust, but the project was cancelled.
Tupolev Tu-134A LZ-TUR, was manufactured in 1974 and delivered new to Balkan Bulgarian Airlines. After 10 year of faithful service fate hit a blow. January 10, 1984 when she crashed on an international flight from Berlin Schönefeld. While on approach to Sofia-Vrazhdebna in heavy snow, the crew failed to make visual contact with the ground as they descended below decision altitude. The crew attempted to overshoot for an altitude of 80 to 100 meters (260 to 330 ft.), but the aircraft hit a power line and crashed 4 km (2.5 mi) from the runway into a forest. The aircraft was destroyed with no survivors.
The Tupolev Tu-134 (NATO reporting name: Crusty) is a twin-engined airliner built in the Soviet Union from 1966 to 1984. The original version featured a glazed-nose design and, like certain other Russian airliners (including its sister model the Tu-154), it can operate from unpaved airfields.
Following the introduction of engines mounted on pylons on the rear fuselage by the French Sud Aviation Caravelle, airliner manufacturers around the world rushed to adopt the new layout. Its advantages included clean wing airflow without disruption by nacelles or pylons and decreased cabin noise. At the same time, placing heavy engines that far back created challenges with the location of the center of gravity in relation to the center of lift, which was at the wings. To make room for the engines, the tailplanes had to be relocated to the tail fin, which had to be stronger and therefore heavier, further compounding the tail-heavy arrangement. During a 1960 visit to France, Soviet leader Nikita Khrushchev was so impressed by the quiet cabin of the Caravelle, that on 1 August 1960 the Tupolev OKB received an official directive to create the Tu-124A with a similar engine arrangement.
Design curiosities of the Tu-134 included a sharp wing sweepback of 35 degrees, compared to 25–28 degrees in its counterparts. The engines on early production Tu-134s lacked thrust reversers, which made the aircraft one of the few airliners to use a brake parachute for landing. The majority of onboard electronics operated on direct current. The lineage of early Soviet airliners could be traced directly to the Tupolev Tu-16 strategic bomber, and the Tu-134 carried over the glass nose for the navigator and the landing gear fitted with low-pressure tires to permit operation from unpaved airfields.
Serial production began in 1966 at the Kharkov Aviation Production Association, and production of the Tu-124 was discontinued. The Tu-134 was designed for short-haul lines with low passenger traffic. Originally the aircraft had 56 seats in a single class configuration, or 50 seats in a two-class configuration. In 1968, Tupolev began work on an improved Tu-134 variant with a 72-seat capacity. The fuselage received a 2.1-meter (6 ft 11 in) plug for greater passenger capacity and an auxiliary power unit in the tail. As a result, the maximum range was reduced from 3,100 kilometers to 2,770 kilometers. The upgraded D-30 engines now featured thrust reversers, replacing the parachute. The first Tu-134A, converted from a production Tu-134, flew on 22 April 1969. The first airline flight was on 9 November 1970. An upgraded version, the Tu-134B began production in 1980, with the navigator position abandoned, and seating capacity increased to 96 seats. Efforts subsequently began to develop a Tu-134D with increased engine thrust, but the project was cancelled.
"Antonov An-24B LZ-AND takes a break between operations".
Note; - The car in the picture looks like a GAZ-69M.
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Antonov An-24B LZ-AND formed part of Balkan Bulgarian Airlines An-24 fleet for almost 40 years in which she crossed the skies of the Eastern Bloc countries numerous times. Unfortunately even for this An-24 service life was running out and in 2007 she seen stored in derelict condition at Sofia.
The Antonov An-24 (NATO reporting name: Coke) is a 44-seat twin turboprop transport/passenger aircraft designed in 1957 and manufactured in the Soviet Union by the Antonov Design Bureau. First flown in 1959, over 1,000 An-24s of various marks were built and 880 are still in service worldwide, mostly in the CIS and Africa. It was designed to replace the veteran piston Ilyushin Il-14 transport on short to medium haul trips, optimised for operating from rough strips and unprepared airports in remote locations. The high-wing layout protects engines and blades from debris, the power-to-weight ratio is higher than that of many comparable aircraft and the machine is rugged, requiring minimal ground support equipment. An-24B was the second 50-seat airliner version with one extra window each side, single-slotted flaps replacing the double-slotted flaps and extended chord of the centre-section to compensate for the lower performance flaps. Some aircraft were delivered with four extra fuel bladders in the wing centre-section. |
A stored LZ-AND (righthand side) at Sofia in October 2007.
Photo: Toma Milosch, Sofia, October 06, 2007. 
LZ-AND some years later at the aviation museum of Burgas.
Photo: Ken Meegan, Burgas, September 2012. |
"Balkan Bulgarian Airlines Ilyushin Il-18D LZ-BEV taxies to her stand at Sofia-Vrazhdebna on a pleasant summer day in July 1979".
A number of East European airlines still flew this classic rugged Soviet workhorse in the late 1970s, but they had been replaced by Tupolev Tu134s and Tu154s on the regular scheduled flights into Western-European airports.
The Il-18 design had started in 1954. The design was for a four-engined low-wing monoplane with a circular pressurised fuselage and a conventional tail. The forward retracting tricycle landing gear had four-wheels fitted on the main leg bogies, the main legs bogies rotated 90 degrees and retracted into the rear of the inboard engines. A new feature at the time was the fitting of a weather radar in the nose and it was the first soviet airliner to have an automatic approach system. The aircraft has two entry doors on the port-side before and after the wing and two overwing emergency exits on each side. On 4 July 1957 the prototype first flew from famous Moscow Khodynka Airport.
The first production aircraft were powered by the Kuznetsov NK-4 but the engines were plagued with problems so the Council of Ministers decreed in July 1958 that all production from November 1958 would use the Ivchenko AI-20 and earlier production would be re-engined. Only 20 IL-18As were built before production changed to the improved Il-18B, this new variant had a higher-gross weight, the nose was re-designed with a larger radome which increased the length by 20 cm. The first Il-18B flew on 30 September 1958 powered by the AI-20, a VIP variant was also built as the IL-18S for the Soviet Air Force.
With experience of the earlier aircraft a further improvement was the Il-18V variant. The Il-18V was structurally the same but the interior was re-designed including moving the galley and some minor system changes. The first Il-18V appeared in December 1959 and was to continue into production until 1965 after 334 had been built. Specialised variants of the aircraft also appeared including aircraft modified for flight calibration and a long-range polar variant. Military variants also appeared including the anti-submarine Ilyushin Il-38.
The Ivchenko AI-20 is a Soviet turboprop engine developed by the Ivchenko design bureau in the 1950s. It has been built in large numbers, serving as the powerplant for the Antonov An-12 transport and the Ilyushin Il-18 airliner. The AI-20 was the first gas turbine engine developed by the design bureau led by Oleksandr Ivchenko based at Zaporizhia, Ukraine. The AI-20s drove four-bladed variable-pitch reversible props with a diameter of 4.5 meters (14 feet 9 inches), featuring prominent prop spinners, and hydraulic actuation for prop pitch. The engines were mounted above the wing and featured integrated fire extinguishers. The engines were started with electric motors, the power for the motors being provided by a ground cart.
The AI-20 is a single-shaft turboprop with a ten-stage axial compressor and a three-stage power turbine, and is designed to run at a constant speed. A big problem with early production engine was the poor reliability of the AI-20 engines, which had a time between overhauls (TBO) in the range of 600 to 750 hours. One issue that was never addressed was noise; turboprops are relatively noisy and high noise levels were a real problem for the passengers. As mentioned, the overhaul life of the engine was initially poor compared with contemporary western engines.
The AI-20M was a significant improvement over the earlier engine variants in all respects. The AI-20M raised takeoff power from 2,985 kW (4,000 shp) to 3,169 kW (4,250 shp), improving takeoff performance under "hot and high" conditions and permitting higher takeoff weights. Higher continuous power ratings were also attained (2700 shp) which made for more efficient cruise. Beyond these, the AI-20M also had good reliability, was lighter, and in particular featured much improved SFC. Serial production of the AI-20M was carried out at Zaporozhye (Motor Sich) and at Perm, USSR in 1958. About 14,000 AI-20s have been built in total.
A number of East European airlines still flew this classic rugged Soviet workhorse in the late 1970s, but they had been replaced by Tupolev Tu134s and Tu154s on the regular scheduled flights into Western-European airports.
The Il-18 design had started in 1954. The design was for a four-engined low-wing monoplane with a circular pressurised fuselage and a conventional tail. The forward retracting tricycle landing gear had four-wheels fitted on the main leg bogies, the main legs bogies rotated 90 degrees and retracted into the rear of the inboard engines. A new feature at the time was the fitting of a weather radar in the nose and it was the first soviet airliner to have an automatic approach system. The aircraft has two entry doors on the port-side before and after the wing and two overwing emergency exits on each side. On 4 July 1957 the prototype first flew from famous Moscow Khodynka Airport.
The first production aircraft were powered by the Kuznetsov NK-4 but the engines were plagued with problems so the Council of Ministers decreed in July 1958 that all production from November 1958 would use the Ivchenko AI-20 and earlier production would be re-engined. Only 20 IL-18As were built before production changed to the improved Il-18B, this new variant had a higher-gross weight, the nose was re-designed with a larger radome which increased the length by 20 cm. The first Il-18B flew on 30 September 1958 powered by the AI-20, a VIP variant was also built as the IL-18S for the Soviet Air Force.
With experience of the earlier aircraft a further improvement was the Il-18V variant. The Il-18V was structurally the same but the interior was re-designed including moving the galley and some minor system changes. The first Il-18V appeared in December 1959 and was to continue into production until 1965 after 334 had been built. Specialised variants of the aircraft also appeared including aircraft modified for flight calibration and a long-range polar variant. Military variants also appeared including the anti-submarine Ilyushin Il-38.
The Ivchenko AI-20 is a Soviet turboprop engine developed by the Ivchenko design bureau in the 1950s. It has been built in large numbers, serving as the powerplant for the Antonov An-12 transport and the Ilyushin Il-18 airliner. The AI-20 was the first gas turbine engine developed by the design bureau led by Oleksandr Ivchenko based at Zaporizhia, Ukraine. The AI-20s drove four-bladed variable-pitch reversible props with a diameter of 4.5 meters (14 feet 9 inches), featuring prominent prop spinners, and hydraulic actuation for prop pitch. The engines were mounted above the wing and featured integrated fire extinguishers. The engines were started with electric motors, the power for the motors being provided by a ground cart.
The AI-20 is a single-shaft turboprop with a ten-stage axial compressor and a three-stage power turbine, and is designed to run at a constant speed. A big problem with early production engine was the poor reliability of the AI-20 engines, which had a time between overhauls (TBO) in the range of 600 to 750 hours. One issue that was never addressed was noise; turboprops are relatively noisy and high noise levels were a real problem for the passengers. As mentioned, the overhaul life of the engine was initially poor compared with contemporary western engines.
The AI-20M was a significant improvement over the earlier engine variants in all respects. The AI-20M raised takeoff power from 2,985 kW (4,000 shp) to 3,169 kW (4,250 shp), improving takeoff performance under "hot and high" conditions and permitting higher takeoff weights. Higher continuous power ratings were also attained (2700 shp) which made for more efficient cruise. Beyond these, the AI-20M also had good reliability, was lighter, and in particular featured much improved SFC. Serial production of the AI-20M was carried out at Zaporozhye (Motor Sich) and at Perm, USSR in 1958. About 14,000 AI-20s have been built in total.
"Tupolev Tu-134A DM-SCF on a sunlit Sofia tarmac in July, 1979. This beauty has the classic lines of the 60's!"
DM-SCF. This 1969 built Tupolev Tu-134A has spent the best part of her life with Interflug from Deutsche Democratische Republic, flying passenger’s services between their base at Berlin-Schönefeld and the rest of the European capitals. In April 1981 she was re-registrated DDR-SCF. In March 1986 her service life was over and she finally ended up preserved the Aeropark museum near Leipzig, Germany.
The Tupolev Tu-134 was the glass nosed version of the russian Jetliner. The first series could seat up to 64 passengers, and this was later increased to 72 passengers. The original designation was Tu-124A. The Tu-134A was the second series. It had upgraded engines, improved avionics and the seating went up to 84 passengers. All Tu-134A variants have been built with the distinctive glass nose and chin radar dome. Some were modified to the B standard with the radar moved to the nose radome.
The Tu-134A's were powered by two 66.7kN (14,990lb) Soloviev D30 Series IIs. The Soloviev D-30 is a Soviet two-shaft low-bypass turbofan engine, officially referred to as a "bypass turbojet."
DM-SCF. This 1969 built Tupolev Tu-134A has spent the best part of her life with Interflug from Deutsche Democratische Republic, flying passenger’s services between their base at Berlin-Schönefeld and the rest of the European capitals. In April 1981 she was re-registrated DDR-SCF. In March 1986 her service life was over and she finally ended up preserved the Aeropark museum near Leipzig, Germany.
The Tupolev Tu-134 was the glass nosed version of the russian Jetliner. The first series could seat up to 64 passengers, and this was later increased to 72 passengers. The original designation was Tu-124A. The Tu-134A was the second series. It had upgraded engines, improved avionics and the seating went up to 84 passengers. All Tu-134A variants have been built with the distinctive glass nose and chin radar dome. Some were modified to the B standard with the radar moved to the nose radome.
The Tu-134A's were powered by two 66.7kN (14,990lb) Soloviev D30 Series IIs. The Soloviev D-30 is a Soviet two-shaft low-bypass turbofan engine, officially referred to as a "bypass turbojet."
"Antonov An-24B LZ-ANL is seen here shortly after arriving back at her home base on a summer day in July, 1979".
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Antonov An-24B LZ-ANL formed part of Balkan Bulgarian Airlines An-24 fleet for almost years in which she crossed the skies of the Eastern Bloc countries numerous times. After 11 years of faithful service with the Sofia based airline her service life was over and she was stored at Burgas for part-out & scrap.
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LZ-ANL at the aviation museum of Burgas.
Photo: Ken Meegan, Burgas, September 2012. |
"Douglas DC-9-32 OE-LDD of Austrian Airlines is seen here about to depart to her home-base in Vienna, Austria".
This DC-9-32, was originally delivered to Austrian Airlines as OE-LDD in 1971. In February 1982 she was exported to the United States of America for a second career with respectively Texas International, Continental and New York Air. In May 2000 she was sold to Aeropostal from Venezuela as YV-49C. In 2006 her service life was over and she finally ended at the Aeropostal technical base at Caracas where she was parted-out and finally broken-up by 2008.
This DC-9-32, was originally delivered to Austrian Airlines as OE-LDD in 1971. In February 1982 she was exported to the United States of America for a second career with respectively Texas International, Continental and New York Air. In May 2000 she was sold to Aeropostal from Venezuela as YV-49C. In 2006 her service life was over and she finally ended at the Aeropostal technical base at Caracas where she was parted-out and finally broken-up by 2008.
"Downtime for LZ-ANK, another member of the Balkan Bulgarian Antonov An-24 fleet".
Balkan Bulgarian Airlines Antonov An-24RV LZ-ANK rolled-off the Kiev-Svyatoshino production-line in 1971. In 1991 she was leased to Palair Macedonian for one year. After more than 25 years of faithful service she was stored at Sofia and finally broken-up during 1997.
The An-24RV (Reaktivnyy V – boosted V) is a turbojet boosted export version, similar to the An-24V but fitted with a 1,985-lb (8830 N) thrust auxiliary turbojet engine in the starboard nacelle.
The An-24RV (Reaktivnyy V – boosted V) is a turbojet boosted export version, similar to the An-24V but fitted with a 1,985-lb (8830 N) thrust auxiliary turbojet engine in the starboard nacelle.
"A nice apron view of LZ-BET - The Ilyushin is almost ready to depart her stand with another load of passengers".
Balkan Bulgarian Airlines Ilyushin Il-18D is seen here from the waving gallery of Sofia-Vrazhdebna Airport being readied for departure. Whilst Tu-134s and Tu-154s were the norm at the time, Balkan Bulgarian still used the occasional Il-18 into Western-European Airports, especially on holiday charters to Burgas at the Black-Sea.
This Ilyushin-18D served with Balkan Bulgarian from 1965. In the late -80s she was withdrawn from use and stripped from useable parts. The fuselage was moved to a children playground somewhere in Sofia. Unfortunately fate hit a blow when she was damaged by fire in spring 1992.
The Il-18D is similar to Il-18I, but equipped with an extra centre section fuel tank for increased range. The Il-18D is fitted with four 3,169 ekW (4,250 hp) Ivchenko AI-20M turboprop engines. Seating is 122 passengers in an enlarged cabin gained by moving the aft pressure bulkhead rearwards by 1.64 m (5 ft).
This Ilyushin-18D served with Balkan Bulgarian from 1965. In the late -80s she was withdrawn from use and stripped from useable parts. The fuselage was moved to a children playground somewhere in Sofia. Unfortunately fate hit a blow when she was damaged by fire in spring 1992.
The Il-18D is similar to Il-18I, but equipped with an extra centre section fuel tank for increased range. The Il-18D is fitted with four 3,169 ekW (4,250 hp) Ivchenko AI-20M turboprop engines. Seating is 122 passengers in an enlarged cabin gained by moving the aft pressure bulkhead rearwards by 1.64 m (5 ft).
"Tupolev Tu-154B CCCP-85223 late afternoon arrival from Moscow with another load of passengers on July 23, 1979".
As the original Tu-154 and Tu-154A suffered wing cracks after a few years in service, a version with a new, stronger wing, designated Tu-154B, went into production in 1975. It also had an extra fuel tank in fuselage, extra emergency exits in the tail, and the maximum take-off weight increased to 98,000 kg (216,053 lb). Also important to Aeroflot was that the increased passenger capacity led to lower operating costs. As long as the airplane had the NK-8-2U engines the only way to improve the economics of the airplane was to spread costs across more seats. Most previously built Tu-154 and Tu-154A were modified into this B-variant, with the replacement of the wing. Max. take-off weight increased to 96,000 kg (211,644 lb). 111 Tu-154B's were built.
The Tu-154B-1 version. Aeroflot wanted this version for increased revenue on domestic routes. It carried 160 passengers. This version also had some minor modifications to fuel system, avionics, air conditioning and landing gear. 64 were built from 1977 to 1978. The Tu-154B-2 is a minor modernization of Tu-154B-1. The airplane was designed to be converted from the 160 passenger version to a 180 passenger version by removing the galley. Some of the earlier Tu-154B were modified to that standard. Max. take-off weight increased to 98,000 kg (216,053 lb), later to 100,000 kg (220,462 lb). 311 Tu-154B-2's were built, including VIP versions. Fortunately a few of them are still in use.
The Tu-154B-1 version. Aeroflot wanted this version for increased revenue on domestic routes. It carried 160 passengers. This version also had some minor modifications to fuel system, avionics, air conditioning and landing gear. 64 were built from 1977 to 1978. The Tu-154B-2 is a minor modernization of Tu-154B-1. The airplane was designed to be converted from the 160 passenger version to a 180 passenger version by removing the galley. Some of the earlier Tu-154B were modified to that standard. Max. take-off weight increased to 98,000 kg (216,053 lb), later to 100,000 kg (220,462 lb). 311 Tu-154B-2's were built, including VIP versions. Fortunately a few of them are still in use.
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Tupolev Tu-154B CCCP-85223 was one of many -154s operated by Aeroflot. The Russian flag carrier announced the retirement of its Tu-154 fleet after 40 years continuous operation. CCCP-85223 made her first flight in the -70s and was withdrawn from use in August 1999. One year later she was transferred to Khahasia Airlines and spotted at Domodedovo Airport in 2002 but still in Aeroflot colors. It is believed she scrapped at Domodedovo somewhere mid -2000.
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Photo: RussianPlane.net
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"There's the whine of a turboprop to be heard! - Balkan Bulgarian, Sofia-Vrazhdebna based, An-24s were hard worked aero-planes".
Balkan Bulgarian Airlines Antonov An-24B LZ-ANF rolled-off the Kiev-Svyatoshino production-line in the late -60's. After several decennia of dependable service she was stored and finally broken-up. Her forward section is preserved at the Aviation Expo oat Burgas airport.
The Ivchenko AI-24 turboprop aircraft engine was designed and developed in the late-1950s by the Ivchenko design bureau and manufactured thereafter by Motor Sich. It was designed to power Antonov's successful An-24, An-26 and An-30 aircraft series.
The most notable feature of the engine was in its operational reliability. The main advantages of the engine were simple design, high reliability, long service life and easy maintainability.
The Ivchenko AI-24 turboprop aircraft engine was designed and developed in the late-1950s by the Ivchenko design bureau and manufactured thereafter by Motor Sich. It was designed to power Antonov's successful An-24, An-26 and An-30 aircraft series.
The most notable feature of the engine was in its operational reliability. The main advantages of the engine were simple design, high reliability, long service life and easy maintainability.
"37 years ago this Antonov/PZL Mielec An-2R HA-MHW trundled over the tarmac of Sofia Airport".
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This An-2 is still operational today and working hard as a crop sprayer from her Dunaujvaros base in Hungaria.
Note; - The green van is a Nysa 522C. |
Photo : Péter Kovács-Ferencz, Dunaujvaros Hungaria, summer 2015.
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"looking a little tatty, this hard working Balkan Bulgarian Airlines Yak-40 arrives back at its Sofia airport base".
Yak-40 LZ-DOF was operated by Balkan Airlines on scheduled services around the Eastern Bloc countries in the late 70's. From 1986 she was part of the Hemus Air charter fleet and from 2001 she was frequently leased to ADA Air and Albanian Airlines for flights from Tirana airport. LZ-DOF eventually ended up stored at Sofia airport.
Note; - The airplane's paint has faded extremely due to ultra-violet exposure.
Note; - The airplane's paint has faded extremely due to ultra-violet exposure.
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LZ-DOF in 2016; - Already on Walk of Fame in front of the administrative building of Bulgaria Air.
Photo: Harry Angelov. |
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"Antonov LZ-ANF seen here shortly after arriving back at her home base on a warm and sunny day in July, 1979".
Due to its rugged airframe and good performance, the An-24 was adapted to perform many secondary missions such as ice reconnaissance and engine/propeller test-bed, as well as further development to produce the An-26 tactical transport, An-30 photo-mapping/survey aircraft and An-32 tactical transport with more powerful engines. Various projects were envisaged such as a four jet short/medium haul airliner and various iterations of powerplant.
Note; - The Antonov is proudly sporting the Balkan Star Wing emblem of forerunner Transportno-Aviacionno Balgaro-Savetsko Oedinenie - (TABSO), on its tail.
Due to its rugged airframe and good performance, the An-24 was adapted to perform many secondary missions such as ice reconnaissance and engine/propeller test-bed, as well as further development to produce the An-26 tactical transport, An-30 photo-mapping/survey aircraft and An-32 tactical transport with more powerful engines. Various projects were envisaged such as a four jet short/medium haul airliner and various iterations of powerplant.
Note; - The Antonov is proudly sporting the Balkan Star Wing emblem of forerunner Transportno-Aviacionno Balgaro-Savetsko Oedinenie - (TABSO), on its tail.
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This Antonov An-24B made its first flight in 1967 and was delivered new to the Bulgarian flag carrier as LZ-ANF. She was operated by Balkan until the mid -90s. Today she her cockpit is preserved in the Aviation Expo museum at Burgas Airport.
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Forward section of LZ-ANF at the Burgas aviation museum.
Photo: Aleksei Grichkov, Burgas, July 2014. |
"LZ-ANB" seen here taxiing at Sofia-Vrazhdebna prior to departing on yet another flight".
This Antonov An-24B made its first flight in 1967 and was delivered new to the Bulgarian flag carrier as LZ-ANB. She was operated by Balkan until the mid -90s.
The main production line of the An-24 was at the Kiev-Svyatoshino (now "Aviant") aircraft production plant which built 985, with 180 built at Ulan Ude and a further 197 An-24T tactical transport/freighters at Irkutsk. Production in the USSR was shut down by 1978.
The main production line of the An-24 was at the Kiev-Svyatoshino (now "Aviant") aircraft production plant which built 985, with 180 built at Ulan Ude and a further 197 An-24T tactical transport/freighters at Irkutsk. Production in the USSR was shut down by 1978.
"A lone Antonov An-30 LZ-AEG was also in Balkan Bulgarian's inventory and is seen here taxiing out at Sofia-Vrazhdebna".
Antonov An-30FG LZ-AEG of Balkan Bulgarian Airlines flew many years for the Bulgarian flag carrier before being sold to Hemus Air. After serveral years of faithful services with this Bulgarian charter airline the 'Clank' was sold and jointed the ranks of the Czech Air Force as 1107.
Antonov An-30FG LZ-AEG of Balkan Bulgarian Airlines flew many years for the Bulgarian flag carrier before being sold to Hemus Air. After serveral years of faithful services with this Bulgarian charter airline the 'Clank' was sold and jointed the ranks of the Czech Air Force as 1107.
"Tupolev Tu-154B P-552 of Chosonminghang (CAAK) of North-Korea is seen here at Sofia under dark threatening skies. The Tupolev just arrived from Pyongyang, North-Korea and stayed overnight".
Note; - The light gray colored car looks like a GAZ Volga M24 stationcar and the black car is also a Volga GAZ M24 but a sedan.
Two wonders of aviation history have shaped the world of air travel; the Boeing 727 and the Tupolev Tu-154. The first flight of the Boeing 727 was in the early 60's and was designed to be a cost saving commercial jet. Almost every large commercial airline in America had a fleet of 727's. Shortly after the first flight of the 727 the Tupolev company in Moscow, Russia (USSR at the time) unveiled the Tu-154. Which looked very similar in design to the 727. Some aviation historians suspect the Russians copied America's plan of the 727. Some others believe the opposite. Just like the 727 in the US, the Russian Tu-154 was the major aircraft in almost every Soviet airline company from the 1960's all the way till the early 2000's.
Now on too the ratings. The Boeing 727 was nicknamed the, "Whisper Jet" honestly this was a joke in the aviation community since the 727 was extremely loud with the J-T8D versions. In the late 80's the 727's were fitted with "hush" kits to make them quieter but the airliner still made a deafening sound when on takeoff and landing. You could actually feel the ground rumble when it went by. On the accident rate, the 727 was mostly low. Like all aircraft, the 727 had its crashes, hijackings and issues. The main problem now with the 727 is, lack of parts, noise, age and fuel economy.
The russian Tu-154, like every aircraft made in the USSR was given a codename by NATO. The codename for the 154 was "Careless". Just like the 727 the Tu-154 was loud, not very fuel efficient and had very bad avionics. 50% of the 110 crashes with the Tu-154 were Pilot Error. If russian flight training was as in depth as the American training then it is believed some of those crashes would not of happened. Also due limited russian radar, avionics and lack of government rules more incidents occurred. One of the perks of the Tu-154 is that it can fly very far, and is now the fastest airliner in the world still flying since the Concord was retired. Also the Tu-154 was also designed for Arctic ventures and short dirt & rock runways.
All and all the 727 and 154 are still used in very limited service throughout the world today. But sadly these aviation legends are going to be out of the skies within the next 10 or 15 years.
Note; - In the background one can see Bulgarian Air Force An-24V with code 040. This 'Coke' was delivered to the Bulgarian Air Force in 1967. In September 2000 she was sold to Heli Air Service as LZ-CBC. In the passing years she was acquired by Dandy Airlines but she remained the registration LZ-CBC.
Now on too the ratings. The Boeing 727 was nicknamed the, "Whisper Jet" honestly this was a joke in the aviation community since the 727 was extremely loud with the J-T8D versions. In the late 80's the 727's were fitted with "hush" kits to make them quieter but the airliner still made a deafening sound when on takeoff and landing. You could actually feel the ground rumble when it went by. On the accident rate, the 727 was mostly low. Like all aircraft, the 727 had its crashes, hijackings and issues. The main problem now with the 727 is, lack of parts, noise, age and fuel economy.
The russian Tu-154, like every aircraft made in the USSR was given a codename by NATO. The codename for the 154 was "Careless". Just like the 727 the Tu-154 was loud, not very fuel efficient and had very bad avionics. 50% of the 110 crashes with the Tu-154 were Pilot Error. If russian flight training was as in depth as the American training then it is believed some of those crashes would not of happened. Also due limited russian radar, avionics and lack of government rules more incidents occurred. One of the perks of the Tu-154 is that it can fly very far, and is now the fastest airliner in the world still flying since the Concord was retired. Also the Tu-154 was also designed for Arctic ventures and short dirt & rock runways.
All and all the 727 and 154 are still used in very limited service throughout the world today. But sadly these aviation legends are going to be out of the skies within the next 10 or 15 years.
Note; - In the background one can see Bulgarian Air Force An-24V with code 040. This 'Coke' was delivered to the Bulgarian Air Force in 1967. In September 2000 she was sold to Heli Air Service as LZ-CBC. In the passing years she was acquired by Dandy Airlines but she remained the registration LZ-CBC.
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Tupolev Tu-154B2 P-552 still soldiers on with Air Koryo and many aviation enthusiast have been travelling onboard this 'Tup', during one of the several aviation trips which were organised by Juche Travel.
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34 years later I was re-united with P-552 at the ramp of Pyongyang, North-Korea.
Photo: Jan Koppen, Pyongyang, 2013. |
The End
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"Antonov An-24 LZ-ANF looks to be in superb condition".
"Tupolev Tu-134A DM-SCF was operated by Interflug flights within Europe and the former Comecon countries". "The classic lines of the Tupolev are so evident in this quarter frontal of Interflug DM-SCF". "1974 built LZ-BFT gleaming on Sofia’s apron in July 26, 1979". "A classic early Jet Liner is this Balkan Bulgarian Airlines Tupolev Tu-134A LZ-TUR". |
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