BFO85FA013

The flt crew rprtd the eng lost pwr when the helicopter was at aprx 100' with a fwd speed of 50 KTS. Witnesses observed faint gray/white smoke emanating from the vicinity of the tailpipe shortly after lift off which trailed & became profuseimmediately before the helicopter began dscndg. Subsequently the acft impacted the gnd in a level, rgt yaw attitude. The rgt main gear collapsed & folded under the belly, the fuel cells ruptured & the tail cone separated from the cabin. An exam revealed that a mixture of fuel & oil had vented overboard thru the flexibox seal drain line. Altho the acft had recently been washed, a hvy fuel stain was noted on the underside of the helicopter from the gang drain to the fenestron. There was evidence that fuel & oil had leaked from the jet holder which transferred fuel from a linear line to a rotating line. However, an exam of the fuel (flexibox) & oil (sealol) seals showed no irregularities. The condition could not be duplicated during bench testing.