Did you secure the unused seat area?

[pelmet]

While this may not be applicable to all light aircraft, I have found that some planes, especially tandem aircraft, can be particularly vulnerable to having the control column interfered with. One type I flew had a metal portion of the seat belt(where the length adjustment is made) that was at just the right location and had just the right size that it could jam the control column at its base(where it entered the floor) if the seat belt happened to be left loose and the right circumstances occurred. Fortunately, I discovered this on the ground prior to operating the aircraft.

Each aircraft type is different(and perhaps different styles of seat belts on aircraft type need to be considered as well). I know nothing about aircraft type in this accident, but I do like to keep the seat belts fastened for empty seats near flight controls(or use them to hold down stuff like my flight bag).

C-IGPN, a Blue Yonder Merlin E-Z Basic Ultra-light aircraft on floats, departed from St. John’s (Paddys Pond) water aerodrome, NL (CCQ5) to conduct circuits with one pilot on board. During the takeoff, the unbuckled passenger seat belt became caught in the control column. The pilot was unable to maintain control of the aircraft which stalled and impacted an island. The pilot egressed with minor injuries and was rescued by witnesses. The aircraft sustained substantial damage.

[final28]

Yes, seatbelts in the other seat of tandem aircraft always secured. In side-by-side if the other seat is empty the belts are secured around CFS, CAP, and any charts or other items I want close at hand.
Any luggage is also always secured. Heard too many stories of things going flying in turbulence resulting in cracked canopies, etc.

[oldtimer]

When the left rear passenger seat is installed in the doorway of a Navajo or Cheyenne, the seat belt can drop out when the door is closed and the buckle will do a real number of the fuselage. If that happens, you can send the F/O back with the door closed and pull the seatbelt in enough so it will not bang against the fuselage. Even with the door fully closed and locked.
Do not ask me how I know.

[tommywcom]

On a slightly different note, I never really understood why you see some planes where all unoccupied seats have their seat belts fastened. I always thought it was just neater that way.

Until someone pointed out to me that because the seats in my Seneca (and in a lot of other ones) are easily removable, so if the seat belts are not fastened, the seats can easily fly out during turbulence or in a crash and hit the other occupants. In fact, the seat belts are pretty much what hold them in place.

[AirFrame]

The four point harness in my passenger seat is always done up, either with a passenger or without. If I left it undone, the belt could jam the controls, the flaps, or just fly around and do a number on my canopy or even me during attitude testing.

[JasonE]

This is standard practice in gliders.

[Redneck_pilot86]

On a slightly different note, I never really understood why you see some planes where all unoccupied seats have their seat belts fastened. I always thought it was just neater that way.

Until someone pointed out to me that because the seats in my Seneca (and in a lot of other ones) are easily removable, so if the seat belts are not fastened, the seats can easily fly out during turbulence or in a crash and hit the other occupants. In fact, the seat belts are pretty much what hold them in place.

That is the stupidest thing I've read all day.

[Broken Slinky]

On a slightly different note, I never really understood why you see some planes where all unoccupied seats have their seat belts fastened. I always thought it was just neater that way.

Until someone pointed out to me that because the seats in my Seneca (and in a lot of other ones) are easily removable, so if the seat belts are not fastened, the seats can easily fly out during turbulence or in a crash and hit the other occupants. In fact, the seat belts are pretty much what hold them in place.

That is the stupidest thing I've read all day.

Yeah, I'd have a real hard time getting into a plane where the seats are held in place by the belts alone.

[tommywcom]

On a slightly different note, I never really understood why you see some planes where all unoccupied seats have their seat belts fastened. I always thought it was just neater that way.

Until someone pointed out to me that because the seats in my Seneca (and in a lot of other ones) are easily removable, so if the seat belts are not fastened, the seats can easily fly out during turbulence or in a crash and hit the other occupants. In fact, the seat belts are pretty much what hold them in place.

That is the stupidest thing I've read all day.

Yeah, I'd have a real hard time getting into a plane where the seats are held in place by the belts alone.

Service letter from Piper:
http://www.spookmate.com/N4870T/SL-763.pdf

"Purpose: There has been one reported accident involving a PA-34 Seneca in which the four (4) aft seats came loose during the accident and were projected forward. The seats were not secured by seats belts. This release provides instructions to properly inspect-the rear seat legs for adequate retention to the disconnect clips to allow compliance with a pending Airworthiness Directive regarding this subject."

[Broken Slinky]

10-15 pounds of force to disconnect the seats from the retention mechanism. The seats have to weigh that alone. Some decent turbulence could pop them free.