Investigators suspect a faulty air-speed indication as a possible cause of the crash of an Antonov An-148 in western Russia on March 5 that killed all six people aboard, Russia’s ITAR-TASS news agency reported. The investigation team has theorized that the pilots, misled by the faulty airspeed indication, inadvertently exceeded the aircraft’s aerodynamic limits.   

Witnesses on the ground reported that the Russian-built regional jet began to break apart while in flight, before crashing onto a private lot in western Russia’s Belgorod region. A piece of the airplane’s horizontal stabilizer and other debris settled to the ground as far as two miles from the crash site, according to local reports.

Built by Russia’s Voronezh Aircraft Production Association (VASO) and destined for the Myanmar Air Force for VIP use, the high-wing regional jet carried four Russian crew and two pilots from Myanmar, reportedly on a training mission. Myanmar’s defense department placed an order for two An-148s in 2009.

The plane disappeared from radar at about 10:40 a.m. Moscow time and Russian television showed flames engulfing the wreckage and smoke billowing from the crash site in a snowy field in the village of Garbuzovo, some 350 miles south of Moscow. A witness cited by the Interfax news agency said the airplane appeared to burst into flames before hitting the ground. The flight originated from Pridacha Airport in Voronezh, Russia, VASO’s exclusively operated airfield. To date, VASO has built eight production An-148s, while Ukraine’s Aviant has completed just two since the airplane gained AMRAK certification in February 2007.