6.2.2 Safety Harness Replacement

This entry is part 41 of 42 in the series 06 - Fuselage

I got the hardpoints installed for the new safety harnesses.

The inertia reel is mounted directly below the Door Post Extension (DPE).  That’s the steel loop that the shoulder harness goes through. In addition to making sure the webbing exits the reel straight up to the DPE, the reel also has to be perfectly vertical front-to-rear and left-to-right. So when installing that hardpoint I had to make sure the face was plumb.

The hardpoint for the DPE was done by cutting a slot in the back of the carbon B-Pillar and inserting the 3/8″, drilled and tapped hardpoint and using structural adhesive to bond it in place.  Then I made a plug and covered the slot.

For the lapbelt hardpoints, I deviated from plans.  With the original harness, I placed the lap belt hardpoints according to plans. Which has the outboard hardpoint right below the rear corner of the door. I get the reason for this location.  1) The belt will be out of the door opening for accessing the rear seats and 2) it would allow the layups covering the hardpoint to be bonded to the carbon fiber B-Pillar which is very strong.

But I noticed an issue with that location. When the seat is moved forward to where you would have it during flight, the lap belt is more aft than down.  Now my pilot seat is very low. but I noticed that it’s not much better on the co-pilot seat.  In the TC aircraft that I’ve flown, the lap belts are anchored farther forward.  What this means is that while they would be effective stopping forward movement, they are almost completely ineffective stopping upward movement (like you would experience during turbulence).  Another issue is that it would allow submarining in the event of a forward stop.  Meaning that you could slide under the lap belt.  This is why they always tell you to place the lap belt “low and tight across your lap.”

Here’s a picture from about 5 years ago to illustrate the situation.

Before (red line is the path of the old lap belt)

seatbelt 1

I did some reading and found there is an optimal angle for the lap belt. So I moved the hardpoints forward of the rear door pin. This will provide improved vertical and forward security.

After

seatbelt 2

Finally, I had sleeves installed on the belt mounted against the keel which will hold the buckle up when no in use.  No more fishing around on the floor for the buckle.

Here’s the copilot side harness (seat is all the way back).

IMG_20160706_092412492

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