J230 Seat Loading

[Alan]

The handbook says the seats in the J230 are rated for 85Kg. Does this mean that If I have a passenger who weighs more than 85Kg that I'm illegal even if my all up weight is within the 600kg limit?

 

Alan

 

 

[Guest sportaviationacademy]

Hi Alan

 

i can't seem to find any referance to a max seat loading in my j230c flight manual

 

could you please post the page /referance to this

 

Regards Glenn

 

 

[Alan]

Glenn,

 

I am away from my 230 for the next few days. Will look up the details then and get back to you.

 

Alan

 

 

[skydog]

Seems logical that if the empty weight plus pilots, plus fuel, plus baggage weight is under 600kgs then you should be within the envelope but I am never surprised so looking fwd to whats in the POH.

 

 

[facthunter]

Seat loading.

 

The seat loading is probably a design limiting factor independant of max AUW . Nev

 

 

[Guest Crezzi]

You are certainly right (at least in the case of trikes) Nev.

 

Its based on the drop tests to ensure the seat doesn't collapse in heavy landings / accidents.

 

John

 

 

[facthunter]

Seat and compartment load limits.

 

These also apply independant of AUW and C of G limits. For instance, you wouldn't want an aerobatic aircraft stressed to 7 G's say, IF the seat collapsed onto the controls and jammed them at 5 G's. The compartment limits relate to floor strength. or tie down point strength... Nev.

 

 

[djpacro]

Just some general comments, which may or may not apply to the Jabiru. ie. I claim no knowledge of the Jabiru.

 

Seats in old GA aeroplanes were designed for an occupant weight of 77kg (aerobatic aeroplanes had a higher figure to allow for a parachute). The current airworthiness regulations for GA aeroplanes has an occupant weight of 97kg.

 

As I'm closer to 97 than 77 I took a keen interest in seat strength of aerobatic aeroplanes. There have been seat failures, more from fatigue than static overload. I took the view that I should have my own, lower limit based on the product n.W - n being the limit load factor and W being occupant weight.

 

Seat structural design is based largely on the crash load cases rather than flight load cases so there may be a bit of reserve in flying hard aerobatics but, in my opinion, pilots should never assume that there is reserve anywhere in the structure. Leads to one of my rules - if you're going to crash do it gently.

 

Rear load on the seat back is simply how hard the pilot pushes on the rudder pedals - many people have the ability to push much harder than the load required by FAR 23.

 

Of course, few aeroplanes mention a seat load limit in the flight manual so that implies there are more significant issues than the above. I've only flown one aeroplane which had such a statement in the flight manual - it was a pusher with the crew up front - limit was determined by bolt strength of the crew module attachment to the main fuselage. That attracted my attention both from the fatigue and static strength points of view.

 

Things end up in flight manuals for various reasons - again, my opinion is not to assume that any of them are silly reasons but it can happen that an enthusiastic inexperienced engineer writes something without realizing the ramifications. Somewhere there is a regulation that pilots shall comply with the flight manual - a good thing to bear in mind.

 

 

[Alan]

Apologies- Cannot find reference in POH

 

OK Sorry chaps but I also cannot find any reference to a 85Kg seat limit in the POH. Just got back from a stint out in the very wet bush up here and have since been through POH at least four times. Perhaps I am loosing my marbles or dreamed it, but I am convinced I have read it somewhere.

 

However, what started this was a discussion with another 230c owner. He concurs he has read it somewhere also. So perhaps we are both having senior moments together. In a desperate attempt to prove we are both mentally fit, we are still looking into this.

 

Again, sorry for ringing the false alarm.

 

Alan

 

 

[Ross]

Hi Allan for interest's sake

 

The Jabiru J160 kit Owners manual that I possess for kit#14 does have a reference to an 85 Kg person sitting with the seat fully forward and a 95 Kg person sitting with the seat fully back (in relation to the "Aircraft load and Trim Chart") on Page 6-8 of the J160 owners manual. A number of other conditions are stated in the example.

 

These two weights and positions are quoted as an example, NOT as a recommendation in reference to forward and aft limits of the C of G. A number of other conditions are stated in the example.

 

Any pilot and or passenger loading must be quoted in conjunction with the "Aircraft Load and Trim Chart" which is too complicated to explain without reference to the example "Aircraft Load and Trim Chart" and the clean unused "Aircraft Load and Trim Chart".

 

However this a/c does not have adjustable seats although the effect can be achieved by placing cushions behind the passenger and pilot's backs as required.

 

It has an "Occupant weight versus Crew index units" chart implying (but NOT stating) a maximum individual crew weight of 120 Kg.

 

The ladder scale for total crew weight on the main part of the "Aircraft load and Trim Chart" goes up in steps of 10 Kg to 300 Kg (but does not say whether the limit is higher or lower than that) which at 300 Kg would not leave much capacity for fuel and other odds and ends.

 

Nothing is said about the structural load carrying capacity of any individual seat.

 

It is all about weight and balance with full tanks and empty tanks.