GyrOZprey
Aussie in Kansas.
On behalf of the Designer of Titanium gyros & CEO of TAG Aviation ,Neil Sheather, I have been asked to post pictures of sections of his TAG rotor ...that was examined in detail by an independent composite engineer ...along with a close scrutiny of the manufacturing process in the composite shop located in West Australia.
We expect his report to be released this week. Neil was pleased to hear the engineer express the opinion " it's one of the best -made rotors i have seen!"
Neil is naturally terribly distraught about the failure of a construction element in the rotors between serial # 20 and 89 ...which have ALL been grounded by ASRA safety directive.
Although the folding -mast plates were initially under close scrutiny ....one of the rotors on the WA Feb accident gyro had clearly lost, in flight, a leading-edge balance weight ...as seen by the cross sections when the rotor was cut up for disposal!
A composite engineer is close to approving a plan to retrofit all the affected rotors by removing the larger steel rod and inserting the original material used for Rotors serial # 1-20 & #90 & above!...leadshot encased in resin!
The obvious question ...WHY did the design get changed for this group of rotors?
The manufacturer found the long stick of resin encased leadshot .... awkward, time consuming & difficult to move into the mold! Neil came up with a recent design update utilizing a long carbon-sock to contain the shot and allow the resin matrix to fix the shot-weight in place inside & outside the sock in the leading-edge space!
THESE updated rotors were already being manufactured ... BEFORE the tragic flight when Robert & James lost their lives!
The composite rotor makers had assured Neil ...they could safely use the long smooth steel rods as leading edge balance weight. Neil understood the high centrifugal forces involved and insisted that they use a knobby rod ( like re-bar) ... that would GRIP & hold in the resin / polyurethane matrix!
Neil stipulated that if smooth rod was used ...IT HAD TO HAVE .notches / grooves cut in the root end to anchor it solidly! ........ sadly the rod was NOT notched ...that departed this rotor!
Without knowing if it was a single oversight ... or ALL the steel-rod weighted rotors were NOT correctly notched-to-anchor! All the rotors between #20-89 are grounded & will be modified before being cleared for flight!
The flight time on the failed rotor was about 150 hours! There were other factors contributing to the story of WHY the weight in this particular rotor broke loose of it's matrix & eventually punched out through the end cap! ( BUT these will have to await revelation after the ASRA final report ..which awaits the coroners inquest ...a 1-2 year process!)
Many hundreds of safe flight hours have been flown on all those other rotors ... that were not stressed beyond POH & design limit!
The test-rotor will have it modification done later this week & be analyzed!
All TAG rotors that fall between #20-89 ...will be modified & have red end-caps installed!
I will add pictures after this gets successfully posted!
We expect his report to be released this week. Neil was pleased to hear the engineer express the opinion " it's one of the best -made rotors i have seen!"
Neil is naturally terribly distraught about the failure of a construction element in the rotors between serial # 20 and 89 ...which have ALL been grounded by ASRA safety directive.
Although the folding -mast plates were initially under close scrutiny ....one of the rotors on the WA Feb accident gyro had clearly lost, in flight, a leading-edge balance weight ...as seen by the cross sections when the rotor was cut up for disposal!
A composite engineer is close to approving a plan to retrofit all the affected rotors by removing the larger steel rod and inserting the original material used for Rotors serial # 1-20 & #90 & above!...leadshot encased in resin!
The obvious question ...WHY did the design get changed for this group of rotors?
The manufacturer found the long stick of resin encased leadshot .... awkward, time consuming & difficult to move into the mold! Neil came up with a recent design update utilizing a long carbon-sock to contain the shot and allow the resin matrix to fix the shot-weight in place inside & outside the sock in the leading-edge space!
THESE updated rotors were already being manufactured ... BEFORE the tragic flight when Robert & James lost their lives!
The composite rotor makers had assured Neil ...they could safely use the long smooth steel rods as leading edge balance weight. Neil understood the high centrifugal forces involved and insisted that they use a knobby rod ( like re-bar) ... that would GRIP & hold in the resin / polyurethane matrix!
Neil stipulated that if smooth rod was used ...IT HAD TO HAVE .notches / grooves cut in the root end to anchor it solidly! ........ sadly the rod was NOT notched ...that departed this rotor!
Without knowing if it was a single oversight ... or ALL the steel-rod weighted rotors were NOT correctly notched-to-anchor! All the rotors between #20-89 are grounded & will be modified before being cleared for flight!
The flight time on the failed rotor was about 150 hours! There were other factors contributing to the story of WHY the weight in this particular rotor broke loose of it's matrix & eventually punched out through the end cap! ( BUT these will have to await revelation after the ASRA final report ..which awaits the coroners inquest ...a 1-2 year process!)
Many hundreds of safe flight hours have been flown on all those other rotors ... that were not stressed beyond POH & design limit!
The test-rotor will have it modification done later this week & be analyzed!
All TAG rotors that fall between #20-89 ...will be modified & have red end-caps installed!
I will add pictures after this gets successfully posted!
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..... plenty of more relevant threads where it was liberally & justifiably added! ...........just smacks of