Airworthiness Directive: Bell 407

[Skidz]

Read this in Helicopters Monthly

 

February 14, 2005

 

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

 

HM Staff

 

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (Bell) Model 407 helicopters that requires creating a component history card or equivalent record for each crosstube assembly, converting accumulated run-on landings to an accumulated Retirement Index Number (RIN) count, and establishing a maximum accumulated RIN for certain crosstube assemblies.

 

This amendment is prompted by fatigue testing, analysis, and evaluation by the manufacturer that determined that run-on landings impose a high stress on landing gear or crosstubes and may cause cracking in the area above the skid tube saddle.

 

The actions specified by this AD are intended to prevent fatigue failure in a crosstube assembly due to excessive stress during run-on landings and subsequent loss of control of the helicopter.

 

See the full AD at

 

Bell 407 AD

 

My question is: Do people do run-on landings on a regular basis in 407s, or in any other skid-mounted a/c ?

[Elvis]

What about training, are run-on landings not part of T/R failure landings?

 

:elvis:

[Skidz]

Yeah, but unless its a training a/c, they won't be performed on a "regular basis", will they ? And how do the crosstubes on a 407 differ from those on a 206L ?

[407 Driver]

I don't know where this AD came from, as we've been counting x-Tube run-on landings for years ??? ...and NO, it's not common to Log any Run-on's in regular Ops.

 

The big difference on X-tubes on a 206 or L vs a 407 is the weight. The AUW in a 407 can be 5,250 Vs 4,150 with an L3, or 3,350 with a 206.

The other difference is the width, the 407 (high) skid tubes are Wide...they sit approx 99" apart, ( a 212 on low gear sits at 104").

[407 Driver]

Ouch, that comment was LOW, I'm hurt

[widgeon]

talking of low , someone once told me that you can estimate the G force of a heavy landing on an angry egg by measuring how much the skids have spread.

 

Does this hold tru for 407 and 350 also ?.

[407 Driver]

Part of a 407's hard landing inspection does include measuring the spread of the skid gear........so I've been told. Honest, I never did it !

 

Way back in the 70's, I recall a 206B on low gear...sitting so low that the hook was in the dirt. now, that was a hard landing (engine driven fuel pump failure). He saved his own life, the passengers lives, and saved the aircraft, except for the skid gear that is.