Mailing List lml@lancaironline.net Message #63633
From: <vtailjeff@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Seat Belt update Legacy
Date: Fri, 28 Dec 2012 15:40:50 -0500
To: <lml@lancaironline.net>
Unknown...it is not tracked by NTSB or FAA.

Sent from my iPad

On Dec 28, 2012, at 12:07 PM, Colyn Case <colyncase@earthlink.net> wrote:

Jeff,

What's the record for occupants submarine-ing with a 3-point airbag belt?
Just curious.

Colyn

On Dec 28, 2012, at 7:37 AM, vtailjeff@aol.com wrote:

I would strongly recommend airbag seatbelts.

Jeff

Sent from my iPad

On Dec 27, 2012, at 8:34 PM, Paul Miller <pjdmiller@gmail.com> wrote:

Agreed.  The Simpson instructions show the geometry for restraint placement.  The Legacy is for me because the straps are slightly above shoulder height.  Other aircraft here have placed a spacer above the backrest to provide that level of protection.  The primary point was those 3-4 foot straps extending back into the fuselage have a 15% extension at impact.   That puts a person's head close to the panel in some cases.
On 2012-12-27, at 6:26 PM, Sky2high@aol.com wrote:

Gents,
 
The shoulder strap ends should not be mounted lower than one's shoulders as this could cause a compression of the spine in an accident.
 
Grayhawk
 
In a message dated 12/27/2012 8:54:41 A.M. Central Standard Time, sdfields68@att.net writes:

Hello Paul,

 

I would like to know more about how you mounted the shoulder straps. I am planning to do the same and don't need to re-invent what you've already done.

 

Stan Fields

L2KR/G # 201

Austin

 

From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Paul Miller
Sent: Wednesday, December 26, 2012 8:58 PM
To: lml@lancaironline.net
Subject: [LML] Seat Belt update Legacy

 

I made a safety and comfort upgrade with my Legacy recently and installed 6-point Simpson belts.  Here are the details and a few things to consider based on input from safety expert Butch Stevens of Simpson who supplied the new belts:

 

1) I removed the inertial reels based on Butch's recommendation because reels are not reliable in high-G impacts.   I also shortened the shoulder straps and bolted them behind the seats.   Belts stretch 15% in an accident so if you want maximum protection from panel impact, remove the long straps from the roof and shorten them as much as possible.

 

2) These Simpson belts and hardware are rated to 14,000 pounds.   Testing shows that most 3,000 lb rated belts don't make that figure.   Butch's Citabria belts only tested to 1800lb before failure.   Original hardware on our TBM 700s failed at 600lb before we complained and an AD came out on the French hardware.  Butch's tests on Hooker failed at less than 3,000lb.

 

3) Belts lose 50% of their strength in two years from sunlight exposure.

 

4) High G pullups and crashes without the 6-points (crotch straps) often find the pilot squeezed down near the rudder pedals because they slide underneath the lap belts.  You must have the 6 points to avoid this problem.

 

I installed the crotch straps to the same mounting point with the lap belts.  I don't believe the mounting location of the lap belt on the center console will hold 3,000 lbs from what I saw on the Legacy so I will have to review that at a later date.  I believe the hard point on the seat back and the fuselage will probably hold. I was thinking maybe of bonding an attach point to the rear spar but I have no data yet on how that might work for the crotch straps.

 

The incremental cost was low for me.  I sold the old hardware, TSO'd belts and reels on ebay for $250 to a Alaska pilot.  This setup from Simpson is available for $299 which is inexpensive for the high quality and ability to handle higher loads and shocks.

 

From a comfort perspective, many of my flights are cross country and the inertial reels always had me bouncing around the cockpit going through Montana in the afternoon or in Texas during the summer.  With these hard points, I cinch down and become one with the airplane.  Control is better in turbulence and I feel liked I'm locked in a little tighter.  The setup is comfortable during long flights.

 

Contact me if you'd like more info on how I attached these shoulder straps or if you have data on mounting the other points.

 

Paul

Spruce Creek

 

 


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