Removing back seat

JOhnH

Touchdown! Greaser!
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I wasn't sure where to post this.

My wife and I are planning a 2 week trip from DAB to PHX at the end of the month. My wife has raised a bunch of Saguaro Cacti from seed and they are getting to the size that she wants to return them to Arizona (that is not why we are going, just an additional task).

Our 172 has a useful load with full fuel of about 800# which should be plenty, but the potted cacti will take up quite a bit of space. My A&P has agreed to remove the back seat and replace it when we return. No Charge.
This would give us a lot more room to haul the cacti plus 2 weeks worth of gear. Plus since we are flatlanders, any reduction in weight will give us more confidence taking off from high altitude airports.

Does this sound reasonable? Stupid? Safe? Legal?
(Please don't ask or comment on WHY we are taking cacti to Arizona :dunno:). But the people at the Arizona Botanical Garden seem pleased.

By the way, is anyone here based at GEU?
 
Does this sound reasonable? Stupid? Safe? Legal?
(Please don't ask or comment on WHY we are taking cacti to Arizona :dunno:). But the people at the Arizona Botanical Garden seem pleased.

By the way, is anyone here based at GEU?

Do it all the time in the Cherokee, in fact, haven't had the back seats in for quite a while. Doubt you will even be able to notice much of a difference. Did do a revised W&B (just happened to have good timing as I was getting the plane re-weighed anyway). I don't see a problem with safety or legality.

Gary
 
I doubt its illegal in general to transport live plants since most of the produce that hits your supermarket is alive and respiring at touchdown. That said, there are some state-specific laws about importing plants and animals. I would check the Arizona statutes very carefully were I our plucky OP. It might very well be illegal to import cacti for fear of introduction of foreign microbes or viruses.
 
I hate to rain on your parade, but isn't it illegal to transport live plants?

I thought of that. I will have to check again though.

The seed packets gave a little history of the Saguaro and suggested that if you raise them away you should return them to AZ when they are a few years old.
And when we called the Arizona Botanical Gardens and asked them, they were happy and volunteered to meet us at the airport. I think they assumed we were flying commercial.

I will try to look into this further, but if anyone happens to know, please advise. But you know how us rabid environmentalists are. Laws are for other people!
 
I have a 6 seater, my back two seats have been out since the day I got it. I love having SUV like storage.

I would also rig up some kind of cargo retention. I use a net or straps hooked to my seat mounts. Otherwise if you had to stop rapidly it could get sticky.:rofl: (its early)
 
I have a 6 seater, my back two seats have been out since the day I got it. I love having SUV like storage.

I would also rig up some kind of cargo retention. I use a net or straps hooked to my seat mounts. Otherwise if you had to stop rapidly it could get sticky.:rofl: (its early)

Yeah, I've thought of that. I'll rig something for sure.
 
As long as you have an A&P signed W&B for that configuration there is no issue. If the seat is permanently mounted (not meant for quick removal) then I believe you'll also need a log book entry; not sure but you probably need the A&P to sign that as well as it isn't part of the standard "pilot approved maintenance" items. The sign off doesn't need to be "glued" into your logbook; just have it paper clipped into the log in case you need it.

For my Baron I have four A&P signed W&B sheets: all seats installed, one rear removed (my standard configuration), both rear seats removed, and all four rear seats removed.
 
I think you also need to make sure you have aircraft records showing the W&B with the seats removed, just like you would if you had other modifications made to the plane. Trying to find the CFR reg that says that, but not having much luck...
 
When driving into AZ, you're required to stop at state inspection ports. Any open fruits & veggies must be tossed for fear of bugs. I don't remember about plants but you really should get the botanical org to confirm there's no problem importing the plants.
 
When driving into AZ, you're required to stop at state inspection ports. Any open fruits & veggies must be tossed for fear of bugs. I don't remember about plants but you really should get the botanical org to confirm there's no problem importing the plants.

I kinda thought so..... but...

I just drove a car down there for a friend a week or so ago and didn't see any state inspection ports... I came from Jackson to Las Vegas on I-15 and crossed into AZ somewhere between the Hoover dam and Kingman AZ... In fact I didn't even see any signs for fruit and veggie inspections.:dunno:
 
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A letter from the FAA rear seat removal.
 

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  • Cessna%20Rear%20Seat.pdf
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That response is specifically for the C-170. Do we dare assume that is covers other aircraft?

By weight and balance couldn't you simply list the negative weight and arm from removing the seat for that flight. Must it be a basic empty W&B sheet signed by the A&P.
 
That response is specifically for the C-170. Do we dare assume that is covers other aircraft?

By weight and balance couldn't you simply list the negative weight and arm from removing the seat for that flight. Must it be a basic empty W&B sheet signed by the A&P.

I see no reason the FAA would not apply the same thinking to the 172.
 
By weight and balance couldn't you simply list the negative weight and arm from removing the seat for that flight. Must it be a basic empty W&B sheet signed by the A&P.

the weight of the seat is deducted from the empty weight of the aircraft and a the moment arm is deducted from the total arm to compute a new Empty weight CG.

then the loading graph in the Owner's manual is used to compute each flight's CG.

the 170 folks that remove the rear seat use two W&B sheets.

we have measured arms for both the rear seat, and the baggage compartments, with maximum weights for each station used in the graph. So does the 172 pretty much the same data is used in both A/C.

IOWs we remove the rear seat, and add 38 pounds to that station for max loading for the rear seat.
 
I wasn't sure where to post this.

My wife and I are planning a 2 week trip from DAB to PHX at the end of the month. My wife has raised a bunch of Saguaro Cacti from seed and they are getting to the size that she wants to return them to Arizona (that is not why we are going, just an additional task).

Our 172 has a useful load with full fuel of about 800# which should be plenty, but the potted cacti will take up quite a bit of space. My A&P has agreed to remove the back seat and replace it when we return. No Charge.
This would give us a lot more room to haul the cacti plus 2 weeks worth of gear. Plus since we are flatlanders, any reduction in weight will give us more confidence taking off from high altitude airports.

Does this sound reasonable? Stupid? Safe? Legal?
(Please don't ask or comment on WHY we are taking cacti to Arizona :dunno:). But the people at the Arizona Botanical Garden seem pleased.

By the way, is anyone here based at GEU?


Rule (or suggestion) #1:

Cushion the Saguaro well. You don't want to be kuddled or hugged by that sweetie while airborne --- especially during approach.

And yes, AZ will be very happy that you are restoring their younguns
;)
 
When driving into AZ, you're required to stop at state inspection ports. Any open fruits & veggies must be tossed for fear of bugs. I don't remember about plants but you really should get the botanical org to confirm there's no problem importing the plants.



That used to be the case; but those inspection ports were dismantled years ago. Now, entry to the state is no more taxing than driving between Eloy and Glendale.
 
Does an electronic W&B work for the FAA or do they have to see a paper calculation?
 
I see no reason the FAA would not apply the same thinking to the 172.

To my understanding, the POH must authorize the removal of the seats.

Most times it's probably a benign alteration, but...

...did the designers include the rigidity of the rear seat structure as part of the overall strength of the fuselage?

...does removing the seats leave anything (control cables, wiring, fuel or hydraulic lines) exposed and vulnerable?

...how strong is the floor beneath the seats, and how much weight can it safely support?

Just things to consider.

I believe that in order to pull the rear seats out of a Cirrus, you must obtain an STC. IOW, someone actually did engineering studies and came up with answers to some of the above issues and solutions to them.

I'll see if I can find a link.

Here it is: http://www.tamarackaero.com/wp-content/uploads/2013/01/carg.tray_.stc_.pdf.pdf
 
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That response is specifically for the C-170. Do we dare assume that is covers other aircraft?
The issue, it seems to me, is not that the letter refers to the 170, but that it lays out why removing the seats is not a major alteration.
It doesn't change the CG, it doesn't change the gross weight, it doesn't change the flight characteristics of the aircraft, it doesn't change emergency egress.

By definition, it is a minor alteration. Therefore, it only requires a logbook entry from an A&P.
Some TCDS's specifically refer to removing seats. If the TCDS and/or AFM discuss it, I would say it only requires an updated W&B.
 
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By definition, it is a minor alteration. Therefore, it only requires a logbook entry from an A&P.
Some TCDS's specifically refer to removing seats. If the TCDS and/or AFM discuss it, I would say it only requires an updated W&B.

It's not even that, Pilot owner can remove it and make the entry.
 
To my understanding, the POH must authorize the removal of the seats.

That was yesterdays thinking, thus the 170 association request for guidance, the resulting letter was the FAA's response
 
To my understanding, the POH must authorize the removal of the seats.

Most times it's probably a benign alteration, but...

...did the designers include the rigidity of the rear seat structure as part of the overall strength of the fuselage?

...does removing the seats leave anything (control cables, wiring, fuel or hydraulic lines) exposed and vulnerable?

...how strong is the floor beneath the seats, and how much weight can it safely support?

Just things to consider.

I believe that in order to pull the rear seats out of a Cirrus, you must obtain an STC. IOW, someone actually did engineering studies and came up with answers to some of the above issues and solutions to them.

I'll see if I can find a link.

Here it is: http://www.tamarackaero.com/wp-content/uploads/2013/01/carg.tray_.stc_.pdf.pdf

Not always the POH. The TCDS is usually thr final authority.
 
OH GOD.................
Interesting comment!
Of course it would be more interesting if I knew where it was directed.
I assume you think it was an awfully stupid question.
 
That was yesterdays thinking, thus the 170 association request for guidance, the resulting letter was the FAA's response

My take is that the FAA considered one particular aircraft, the 170, and the resulting letter referred to its opinion on that particular aircraft.

I don't think that ruling applies to a Cirrus, hence the need for an STC.

A 172 may be very similar to a 170, but I don't think one can just assume the FAA's letter applies to it. Or a 150, 210, Skymaster, whatever.

An aircraft owner or mechanic can certainly guess which parts he or she can safely remove and still have an airworthy aircraft. As I said, removal of many items, including the rear seats, is probably benign in most aircraft.

Just be careful - there may be unintended consequences, both practical and legal.
 
And when it says nothing?

I don't think that should be taken as any sort of banket approval.

Things like prop spinners, cowlings and the like may be optional - or their presence may be critical to cooling and airflow.

Things like wheel pants may be optional - but unless approved and documented, on their removal one would be left with no accurate performance charts - and the fairings themselves may provide protection for brake lines that would otherwise be vulnerable.

This can certainly seem silly in any particular case. And we're all adults here. So do what you want, but try to be mindful of the possible practical and legal implications.
 
Good point. Thanks.

Keep in mind the TCDS is not a parts list, and does not include what parts can be removed and still remain in an airworthy condition.

It will give alternate parts and components that can be used and the parameters that they are to be operated.
 
Does an electronic W&B work for the FAA or do they have to see a paper calculation?

I would recommend a paper copy with an A&P signature for each aircraft configuration.

All I'd likely charge for that (baring any real work like removing the seats to weigh) would be a coke
 
To my understanding, the POH must authorize the removal of the seats.

Most times it's probably a benign alteration, but...

...did the designers include the rigidity of the rear seat structure as part of the overall strength of the fuselage?

...does removing the seats leave anything (control cables, wiring, fuel or hydraulic lines) exposed and vulnerable?

...how strong is the floor beneath the seats, and how much weight can it safely support?

Just things to consider.

I believe that in order to pull the rear seats out of a Cirrus, you must obtain an STC. IOW, someone actually did engineering studies and came up with answers to some of the above issues and solutions to them.

I'll see if I can find a link.

Here it is: http://www.tamarackaero.com/wp-content/uploads/2013/01/carg.tray_.stc_.pdf.pdf


I would recommend taking your concerns into account, for example I wouldn't fly with the rear seats out of a Cirrus, the inspection panels below are non load bearing
 
I would recommend a paper copy with an A&P signature for each aircraft configuration.

All I'd likely charge for that (baring any real work like removing the seats to weigh) would be a coke

What regulation requires the W&B be completed by an A&P?

Cessna provides the DATA in their Owners Manual. and the Owners Manual is a required Placard that is to be uses to compute the W&B for the flight as a portion of the flight.

All the pilot needs to know is the A/C empty weight, Total Moment, weight at each station of the graph to do the computation.
 
What regulation requires the W&B be completed by an A&P?

Cessna provides the DATA in their Owners Manual. and the Owners Manual is a required Placard that is to be uses to compute the W&B for the flight as a portion of the flight.

All the pilot needs to know is the A/C empty weight, Total Moment, weight at each station of the graph to do the computation.

Way it was presented to me is that removing the seat (especially when bolted in) changes the EW of the plane.
 
When driving into AZ, you're required to stop at state inspection ports. Any open fruits & veggies must be tossed for fear of bugs. I don't remember about plants but you really should get the botanical org to confirm there's no problem importing the plants.

No inspection ports in the Land of AZ. I think you're thinking of the People's Republic of California.
 
Wow, there's sure a lot of conflicting info here!

Check the equipment list. It will give weight, moment and tell whether it's optional.

I'm pretty sure that the rear seats on a 172 are optional items, so you can put them in or take them out as you like, with just a logbook notation.
 
Way it was presented to me is that removing the seat (especially when bolted in) changes the EW of the plane.

It does change the EW by 38 pounds. That does not meet the requirements of FAR 43 A as a major change.
When you change the W&B to a weight over the allowable by the TCDS then that will be a major. but decreasing it? No.

My W&B graph in the O/M simply says that I can load XX at that station so we add 38 pounds to the weight we can carry there.
 
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