July 16 (Bloomberg) -- Tupolev Tu-154 airliners like the one that crashed in Iran yesterday, killing 168 people, are Soviet-era Russian workhorses whose safety record falls short of Western designs.

The Tu-154, which first flew in 1968, has a fatal accident every 431,200 flights, according to London-based aviation consultant Ascend. Boeing Co.’s MD-80 has a fatality every 1.5 million flights and the 737, the world’s best- selling passenger plane, every 2.68 million, Ascend says.

“The 154 is by a wide margin the most successful jet ever built by a communist economic system,” said Richard Aboulafia, vice president at Teal Group, a Fairfax, Virginia- based consultant. “It was created at the height of the old Soviet Union’s ability to invent equipment that at least approximated the achievements of the West. The real problem is regulatory oversight in many of the regions where it’s used. Corruption and neglect almost guarantee trouble.”

The latest crash was the eighth fatal incident involving a Tu-154 in 10 years, including one act of sabotage. The crash took the total number of losses for the type to 54 since it entered flight service in 1971, resulting in 2,860 deaths, according to Ascend data. The 23-year-old plane operated by Caspian Airlines came down 16 minutes after takeoff from Tehran en route to Armenia.

Technical Problem

The accident may have been triggered by a “technical fault,” Iran’s state-run Mehr news agency said today, citing Ahmad Majidi, a deputy transportation minister. Caspian Air yesterday refused to comment on the likely cause before an examination of the plane’s flight-data recorders, the Russian Interfax news service said. Searchers have so far found two of the so-called black boxes, Press TV reported today.

The disaster was the sixth fatal accident involving a passenger flight this year and the first involving an eastern- built airliner. The crashes have claimed more than 600 lives.

Of the 829 Tu-154s that have seen service with airlines, 208 -- one quarter -- are still in operation, according to Ascend. The three-engine model can carry 164 to 180 passengers, the Web site for Moscow-based Tupolev says. Caspian Airlines had five of the aircraft and hadn’t previously had a fatal incident. It had leased the crashed plane since 1998, Ascend said.

Production Collapse

While Tu-154 production collapsed with the end of the Soviet Union, planes continued to be constructed in small numbers and including one in 2007, said Paul Hayes, director of safety at Ascend, which tracks aviation data for clients including insurers.

The fatal accident figures are a five-year average in Ascend’s Airline Loss Rate studies.

Spare parts are still in good supply because of the Tu- 154’s high production run and oil prices have been the main reason for reduced operations in recent years, said Boris Rybak, head of Infomost Aviation Consulting Group in Moscow. Russian airlines began to ground the aircraft last year, leaving the Middle East, China and Africa as the biggest operators, he said.

“Almost all Tu-154s still in service are with former Soviet and Third World airlines, particularly in closed or semi- closed markets that don’t like doing business with the West or can’t afford anything better,” said Teal’s Aboulafia.

Iran’s aviation safety record is affected by maintenance issues, high-altitude airports and a hot climate that takes a toll on aircraft and flying conditions.

In September 2006, an Iran Air Tours Tu-154 caught fire and crashed on landing in the northeastern city of Mashhad, killing about 30 people. Yesterday’s incident brings the number who have died in air disasters in the country to 1,610, according to safety data cited by Mehr.

Trade Ban

A U.S. trade ban on Iran means the country can’t buy spare parts for its aging fleet of American aircraft, purchased before the 1979 Islamic revolution, except on the secondary market. Russia and Iran signed an accord in 2008 for sales of 100 Tupolev Tu-204 and Tu-214 planes over a 10-year period.

Asadollah Abbasi, a member of Iranian parliament, said today that the country has to operate Tupolevs because of the sanctions, according to the state Islamic Republic News Agency.

The Tu-154 is a generally reliable model, said David Learmount, a former U.K. Royal Air Force pilot and air-safety editor at Flight International magazine.

“Its safety record is good but not quite comparable with that of a modern Airbus or Boeing,” Learmount said. “The pilot’s situational awareness is not up to what a modern cockpit can give you.”

Loss of Control

Learmount said it’s too early to speculate on whether the model’s age or characteristics played any part in yesterday’s disaster. The plane appeared to have come down about half-way into its climb, he said, with the nature of the impact suggesting a loss of control. Debris was scattered across an area stretching up to 15 kilometers (9 miles), Mehr reported, without citing anyone.

“It would certainly help Iran to have access to modern Airbus and Boeing aircraft,” Learmount said. “With each successive generation of airplanes, safety has improved.”

While Iran can buy modern planes on the second-hand market, “it’s very awkward to operate like that because you then need service backup and parts,” Learmount said.

To contact the reporter on this story: Maria Ermakova in Moscow at mermakova@bloomberg.net; Susanna Ray in Seattle at sray7@bloomberg.net

Last Updated: July 16, 2009 08:19 EDT