Mi-17 Life Extensions, Questions and Answers

What is the current life of of a civil Mi-17 variant helicopter?
By bulletin № T2775-БЭ-АБ, issued on 24 December 2009, the assigned life time of all civil variants is 12000 hours.  Aircraft produced prior to 1991 have calender lives of 30 years.  Production after 1991 have service lives of 25 years.  This bulletin superseded № 2133 issued in 2004.

Bulletin 2775 Life Extension

Can the assigned calender service lives given above be exceeded?
Yes, the Mil Design Bureau can extend an aircraft during overhaul until the total allowed flight hours (12000) have been reached.

Why does this bulletin specify that it applies only to civil aircraft?
Mil is a civil aviation company and has no authority to address the airworthiness of military aircraft.  Therefore, for a Mil bulletin to apply to military aircraft, it must be endorsed by the respective military's internal air worthiness authority.

Is there a specific bulletin that can extend the life of military Mi-17 type aircraft?
Yes, there is one for Mi-8MT aircraft (export designation Mi-17).  Bulletin No. 3071 was issued issued jointly by the Russian government and Mil, and signed by the Russian Air Force (as the Air Force, not Mil, has airworthiness authority over Russian military Mi-17s).  This bulletin extends the life of the Mi-8MT aircraft to 35 years, and authorizes overhaul facilities to extend it indefinately.  For it to be in effect in a particular country, it must be adopted by that country's military air worthiness authority.  This 2010 bulletin superseded bulletin 2133 issued in 2004.

Bulletin 3071 Life Extension