MU-2B 40 Solitaire
Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 55; Flight Crew Total 26000; Flight Crew Type 3800
Aircraft Equipment Problem Critical; Ground Event / Encounter Ground Strike - Aircraft
Aircraft Aircraft Damaged; General Maintenance Action
Aircraft
Upon landing on Runway 09 in ZZZZ; Nose Landing Gear (NLG) failed during roll out.  Flight was uneventful; no other traffic reported; and a straight in Visual Approach was executed.  Flaps and gear where extended a good 15-knots below the maximum speed. Three Green gear lights where observed; and Power Lever Gear Warning sound was observed; as power reduced for the touchdown. Then five to seven seconds into the rollout; the nose gear failed. Managed to get 3/4 of the aircraft off the runway into the taxiway. Had some directional control during the gear failure. Managed to raise the nose unto a trailer; and tow the aircraft to the ramp.
Reporter stated the Nose Landing Gear (NLG) has been an issue on this particular 'P' Series MU-26B-40 aircraft.  His aircraft is not the lighter Solitaire model; but the heavier 'P' series with four-bladed props; a 45-lbs aircraft battery mounted right above the (NLG) along with the aircraft's electronic equipment. All that weight up front made the 'P' series nose heavy; compared to the Solitaire where the aircraft battery and electronic equipment were moved to the tail section area; the fuel configuration was different and only three-bladed props were installed. But; the same NLG was used on both models; no modifications of the NLG for the 'P' Series.Reporter stated when one of the two drag brace rod ends broke at the cross bar attachment; the NLG collapsed and came up against the closed Gear doors. But; since the other drag brace held; the NLG ended up being cocked over with just enough of the nose gear tire contacting the ground that he could maneuver most of the aircraft off the runway. Reporter stated that a contributing factor to this incident was the slightly different lengths in the drag braces; even though the Part Numbers (P/N) are the same. Although adjustments are made at the cross bar; there was a 1-MM difference in length. The nose comes down almost immediately on landing due to the heavier forward fuselage section compared to the Solitaire model where the weight distribution is more even.  The NLG brace was replaced with the NLG locked in the 'Down' position and ferried to one of the Manufacturer's Repair station. Aircraft's speed was limited to 150 knots with gear down; otherwise 280 knots would be their cruising speed.   Over the past three years; every component of the NLG has been replaced for one reason or another. After reviewing the estimated cost for repairs from this incident; they decided to part out the aircraft and keep the engines.
Captain reports the Nose Landing Gear (NLG) on a Mitsubishi MU-26B-40 (MU-2P) aircraft failed (collapsed) five to seven seconds into the landing rollout. A rod end for one of the two NLG Drag braces had broken at a crossbar that co-ordinates extension and retraction.