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TT Straps

TT Straps

TT Straps

Oh the joys of Jet Ranger ownership!

My two years are up and the life of my (probably perfectly serviceable) Tension Torsion (TT) Straps has ended.

The straps only have a 1,200 hour life,  or 24 months, and are probably the biggest complaint of every Jet Ranger owner (and for that matter, every other helicopter owner that utilises them,  including the boys from G-LADZ). The straps are really a large rubber band and effectively keep the main rotor blades attached to the mast.

The straps were traditionally changed “on condition” but  3 serious incidents of TT Strap separation changed all that. These incidents took place over an 11 year period covering nearly 7,000,000 flight hours. All the incidents were judged to be from corrosion which had occurred because the aircraft concerned were operating in a highly corrosive environment.  Bell then issued a directive that the straps should be replaced every 1,200 hours. A further insident with a Bell 212 at 22 months, then added the 24 month restriction. Most JetBox pilots argue that the limitation should not apply unless the aircraft is operated in a similar environment to the incident related aircraft (though to be sea water). But in 2004 bell stated:-

“In aircraft certification terms, it is not possible for different retirement lives to be assigned a given part number contingent upon the operating environment. Therefore, just as in all published retirement lives, the existing 24-month retirement life results from the worst-known case.”

Apparently Bell are testing a new design which might increase the life to 36 months but to date, although the straps are being evaluated in the field, they have not yet received approval.

So until then we’ll all be chucking perfectly serviceable parts in the bin at an extortionate £6k-£7K price tag and you guessed it, my machine is off to PDG at Wolverhampton for two days.!

“Ouch” does not begin to describe it!!!!

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2 Responses

  1. Thought you might like the enclosed link, its called ditch the Jet Box & Range Rover and buy a Terrafugia Transition. We could line up a runway
    in Waterfold Park!

    http://cars.uk.msn.com/News/car_news_article.aspx?cp-documentid=15237105

  2. i got ride in the jetbox FANTASTIC!

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