Cessna's Free Seat-Stop Installation -- Any Downside

[Paul462]

Cessna Pilots Association technical support suggested three downsides to this installation:

1. Cost. Although the initial install may be free, belt fraying will occur over time due to the angle of the belt relative to the reel housing. When the time arrives to replace the reel/belt assembly, it probably won't be cheap, and that cost will be borne by the owner.

2. Removal of existing effective retrofit stop. One previous back-up stop design involved a spring-loaded clip which was removably attached to the rail, and apparently it worked well. Installation of the belt mod requires removal of this stop.

3. Reliability. When the belt eventually frays and hangs up inside the reel, it could prevent the original rod from fully descending into its rail bore, because the belt and the original rod are mechanically interconnected. The frayed belt could thus defeat both the "free" mod itself AND the original seat lock, causing the seat to slide backwards upon takeoff.

The CPA rep I talked with knew of one pilot who had never had his seat slide backwards on takeoff UNTIL he installed the belt mod. The seat slid backwards twice on takeoff. He took his plane back to the pilot center, which pronounced the install fixed. Shortly thereafter the pilot's seat slid back yet a third time! The pilot ended up removing the mod.

4. Bonus draw-back: you can't store stuff under the pilot seat anymore because of the reel.

Conclusion: I decided not to install the belt mod. The CPA rep noted that if the entire original system (rollers, rail, rod, etc.) is kept in good condition and within tolerances, it'll work just fine.

I make it a habit to push my seat forward and backwards at the very start of my take-off run, to confirm the seat is well-locked into place. If I were ever to note any movement at this point, I would simply abort the take-off.

This is a good habit to get into whenever flying a SE or light twin Cessna, be it a C150, C172, C182, P210, C337, etc. - one can't be assured that they all have back-up stops installed. :-)