Proton Failure Traced To Ruptured Gas Duct

[Satellite Today – 4-22-08] A rupture of the gas duct between the gas generator and the propellant pump turbine in the Breeze M main engine led to the March  failure that left the AMC-14 satellite in a useless orbit, International Launch Services (ILS) said April 21.
    The findings by the Russian State Commission investigating the failure said the most probable cause of the gas duct rupture was due to the combined effects of duct wall erosion, high temperatures and prolonged low frequency pressure fluctuation in the duct. Khrunichev, which manufactures both the Proton booster and the Breeze M upper stage, has been directed to perform corrective actions to fix the problems as well as improve the reliability of the Breeze M main engine before the vehicle can return to flight.
    A Failure Review Oversight Board created by ILS also will review the findings then travel to Moscow at the end of this week for official briefings on the
findings and corrective actions. The board will determine if the corrective actions meet ILS standards for commercial return to flight.
    “We and our partner, Khrunichev, are committed to a credible return to flight and an overall Proton recovery plan that restores customer confidence and future mission success,” Frank McKenna, president of ILS, said in a statement.