By Joanna Bailey

A Caspian Airlines Boeing 737-400 has suffered a gear collapse on landing at Isfahan in Iran. The left main gear of the aircraft collapsed on touchdown, causing the plane to veer to the right and exit the runway. The aircraft was evacuated via emergency slides, leading to five passengers being injured.

Classic 737 loses its gear

There aren’t a whole lot of Boeing 737-400s in regular passenger service any more, with ch-aviation recording just 74 presently active out of a once global fleet of almost 500. But in Iran, where airlines have been hampered by sanctions restricting the purchase of new aircraft, many of these classic narrowbodies are still regular workhorses.

For one such aircraft, yesterday’s flight didn’t go quite to plan, after it suffered a landing gear collapse as it touched down. The flight, operated by Caspian Airlines, was traveling from Mashad to Isfahan, both in Iran, with 117 passengers and nine crew onboard, according to the Aviation Herald.

Flight RV-6904 touched down on runway 25R at just after 17:00 local time, but the left hand main gear collapsed immediately on contact. The loss of the landing gear caused the plane to swerve to the right, veering off the runway and coming to a stop with the nose gear off the paved surface.

With the plane listing at an angle, evacuation proceeded via emergency slide. Reports suggest that three female passengers received minor injuries as a result of the slide evacuation, while two male passengers had serious injuries including fractured bones.

The incident aircraft, EP-CAP, is one of three 737-400s operated by Caspian Airlines. It is presently the only one in service, with the others listed as being stored or in maintenance. It has been a part of the Caspian fleet since August 2015, but was originally delivered to Malaysia Airlines in October 1992.

Iran’s maintenance problem

While the Caspian Airlines gear collapse could be a result of a multitude of factors, there is a known issue with ongoing aircraft maintenance in Iran. Airlines like Caspian have been forced to hold onto their aging fleets for the long term, as sanctions have prevented them from investing in newer and more reliable aircraft.

Like many Iranian airlines, the Caspian Airlines fleet is entirely made up of older and obsolete aircraft. Alongside the -400s, it flies a pair of 737-500s, and five MD-82/83s, all of which are approaching or older than 30 years of age. Accompanying these are two 43-year-old 747-200Fs and a single 747-100SF aged an astounding 52.5 years old.

The problem for Iranian airlines is not only their inability to renew their fleets, but also the lack of supply of spare parts for the existing fleets already in the country. Just yesterday, the head of the Civil Aviation Authority in the country said Iran plans to take Airbus and ATR to court over a lack of supply of spare parts. Mohammad Mohammadi Bakhsh warned of a ‘major incident’ if local airlines were unable to maintain their aircraft. At present, more than half the nation’s passenger aircraft are grounded due to maintenance issues.