The International Cessna^® 170 Association

And now a tidbit to spice up the conversation A copy of the STC that comes with Atlee Dodge Jump seats.

Cessna 207 airplanes may be certificated under FAR 23 and Cessna may allow more than one seating configuration as part of type design. This would allow for change in seats without a 337. I remember the 402s we flew in the 1970s could be changed to cargo configuration by the pilot after we had training. No 337s were involved. We used to fly them into Redding, CA with passengers, remove all seats, install cargo net, and fly US mail back to SFO monday - friday. The FAA used to ramp check us in San Francisco all the time and I never heard of a complaint unless we didnt have the cargo net secured properly. The approved AFM in a 402C had a cargo configuration and the company had two W&B forms one for cargo, one for pax. I think 170s were certificated under CAR 3 and there is less leeway in how the owner can change configuration. The 337s I have had to file for alterations of a Cessna 170 have been a no brainer and I have learned (the hard way) that a buyer should check them before signing on the bottom line. BTW, the Atlee Dodge STC above is hard to read.

Click on the image and it will enlarge to a size more than sufficient to read. (I'm not certain what John's intent is in posting that document, or how it applies to the controversy being discussed.)

The approval extended to FAR Part 135 operators is only for the purpose of allowing PILOTS to perform the maintenance function of seat removal. It does not provide a basis of approval to operate the airplanes without required equipment such as seats specified in the TCDS. (If the operator has a basis of approval to alter the configuration of the aircraft, ... such as might be documented with a Form 337 which documents the change.... then the pilots, with the approved training program, will be authorized to make the conversions/alterations back and forth as the operator requires. It does NOT authorize the pilots to alter the airplane to an unapproved configuration.

The "typical" equipment list is only that.... an example of one that is typical.... not one that is applicable. It is not a specific one that applies to specific aircraft. And even more important, it does not prove that seat removals are authorized alterations. Example: Notice that it also lists the Flight Manual in that same list, yet we know that the Flight Manual is ABSOLUTELY required equipment to be onboard a Cessna 170! Another example: It also includes radio antennas, yet I dare anyone to suggest that removing a radio antenna is 1) an operation authorized to pilots, or 2) an alteration that does not require documentations such as a Form 337. Another example: That "typical" equipment list includes an ELT. There is surely no one in this discussion who will argue that it's permissible for the pilot to completely remove a radio installation or that such removal is a "minor" alteration,... regardless of the fact the FAA might have issued that letter suggesting it.

Sorry George, you and I will have to agree to disagree. You will notice that the Flight Manual is listed as -R which is "required" equipment not "standard" equipment. Nice try tho. I don't know how the FAA could make it any clearer. If you wish to continue to fill out unnecessary 337 forms have at it. It is this CYA attitude that has created a problem for the rest of us, the FAA receives so many useless 337s they now expect them when they are not required. Regarding pilots removing radios, I never suggested that could be done by a pilot. I did say it removing equipment only required an A&P and only required a log book entry and revised W&B.

Yes, the AFM is required equipment, yet the "typical" list posted was used to suggest it could be dispensed with. The seats are required because they are "basic" equipment, and therefore require support as a major alteration. (A comparative example might be a windshield. Could the pilot simply remove it and go fly?)

I agree with you that many Form 337's are unnecessary. An example might be the replacement of a navcom radio. If an aircraft is certificated with a radio-rack and If the aircraft already had a com radio, and the existing radio were simply replaced with another make/model that required no alteration of structure, then no Form 337 should be required. (This is the most common type of 337-abuse seen.)

I only post the bottom portion of equipment list. The top section explains required and standard and optional equipment. Again, I never said any of this could be signed of by a pilot.

Hmmm i made a long post but it is gone must have been the MAC. will try again...
I don’t have a 170 poh so i do not have any examples from there.

Reasons why removing your rear seat or your co-pilot seat is NOT A MAJOR ALTERATION.

1. Page 66 of my 1956 172 Owners manual has a note in the top RH page that says " Measurements are with co-pilot seat, rear seat, and baggage compartment shelf removed - giving maximum useable areas and saving 40lbs on empty weight. " This page pictures a pilot seat only and gives cabin dimensions with just the pilot seat. Cessna would not have put this in the owners manual if you could not do it. THIS IS NOT A MAJOR ALTERATION.

2. Page 6-8 of a Cessna 180K POH shows four "Loading arrangements." One has pilot seat only. One has pilot and co pilot seat only. One has pilot, co- pilot, pass seat, and 3rd row seat. One has pilot, co pilot, rear seat only. The note on page 6-7 says " When loading is light (such as pilot and copilot, and no rear seats or cargo), be sure to check the forward balance limits." The 180 is also listed as a 4 PCL on the type cert, like the Cessna 170. Do you think Cessna put this in the 180 poh just for the hell of it? No. THIS IS NOT A MAJOR ALTERATION.

3.

The approval extended to FAR Part 135 operators is only for the purpose of allowing PILOTS to perform the maintenance function of seat removal. It does not provide a basis of approval to operate the airplanes without required equipment such as seats specified in the TCDS. (If the operator has a basis of approval to alter the configuration of the aircraft, ... such as might be documented with a Form 337 which documents the change.... then the pilots, with the approved training program, will be authorized to make the conversions/alterations back and forth as the operator requires. It does NOT authorize the pilots to alter the airplane to an unapproved configuration.

The intent of the regulation is obviously not to allow pilots to do MAJOR alterations to airframe seating configurations. The intent is to allow 135 pilots to remove and install seats for cargo/ pass operations. Removing seats is a preventative maintenance function. 135 pilots are not allowed to do preventative maint. FAR 43.3 (i) allows 135 pilots to perform this function that they previously were not allowed to do. The approval basis is the POH in most cases.

4. Major alterations to seating configurations are---
a. Installation of FAD jump seats. There is an STC for this listed above. The STC refers to the seats as “removable.” This is because they are easy to remove unlike that Cessna bus seat. I know you were trying to give it as an example for approval to remove seats but that is not the intent of that STC.
b. Installing your seat in an AFT facing configuration.
c. installing a bar stool for a seat, or milk crate.

5. To this date I have never read any 337 with the approval for seat removal in a Cessna 170.

George,
I too could have sworn that years ago at a IA renewal seminar the FAA said that a 337 is required for seat installation/removal. But Bill O'Brien says that a logbook entry and two w&b forms are all that is required. See Cessna Pilot's Association Vol. 23, No. 7., pg. 8512 (July 2006).

gahorn wrote:It also includes radio antennas, yet I dare anyone to suggest that removing a radio antenna is 1) an operation authorized to pilots, or 2) an alteration that does not require documentations such as a Form 337. Another example: That "typical" equipment list includes an ELT. There is surely no one in this discussion who will argue that it's permissible for the pilot to completely remove a radio installation or that such removal is a "minor" alteration,... regardless of the fact the FAA might have issued that letter suggesting it.

There is no reason to file a 337 to remove an antenna. There is no reason to file a 337 to remove a ELT. Show me in part 43 Appendex A where these would be considered Major Rapairs or Alterations.

It was perhaps an unfortunate selection for me to have singled out the ELT as an example, but the point is that the PILOT may NOT remove/install these items.

"mod cessna" I see nothing correct in your last post, beginning with the reference to a document which does not exist for a Cessna 170..... (poh). The other examples you give are not germane, as they are different aircraft and Cessna marketing photos. If marketing information were certified we'd all be making 145 hp on takeoff.

Cessna also had photos showing stretcher patients and nurses in an ambulance modification. Since that modification was a factory configuration, ... IF the owner purchased that configuration ... THEN that configuration would be legal. YOU don't have that configuration in your aircraft and YOU cannot perform that alteration on your own, without a Form 337.

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It might be best at this point to mention something. This subject/thread, like many others here at the forums, was begun by a question from one of our participants/friends who posed a question and doubtless wanted an answer that was as correct/helpful/accurate as possible.

When questons are asked, it's likely that several responses may apply, and that while in some cases a "Yes" or a "No" or a "THIS way" or a "THAT way" can be readily supplied and easily shown to be absolutely true...... there are also cases where there is no ONE correct answer, or cases where a certain amount of experience, or opinion, or perhaps both, might supply some direction to the questioner.

In this particular discussion there are obviously some differences of opinion. And there are some strong "feelings" perhaps. Some participants might feel very strongly and quite emotionally about what is "right" or "wrong" possibly based on fact or experience,.... possibly not, but simply on what is felt to be "common sense". I can appreciate that. I have some understanding in that regard.

The fact is... I do not like the answers I personally make to some questions either. I actually agree with the opinons of many that removing a rear seat is a relatively un-important matter. In fact, I would really, truly like to be able to say "There is no need to document the rear seat removal." I'd love to be able to take my rear seat out of my airplane and fly a pile of Christmas gifts to my family down in Houston without having to cover my arse with a pile of paperwork describing what is essentially a simple matter and a minor removal of dead weight.

But I cannot make that response here because that is not right. The questioner is not asking just for their own information, they are also asking for every other reader who visits these forums for the next ten years and stumbles across this discussion and wonders "Hey! Why don't I just yank that seat out and save a bunch of dead weight even if I DON"T need to haul anything back there but a pillowcase of feathers!"

While one person might fly with only a log entry regarding wt and bal information and get away with it in Alaska.... another guy might find themselves on the ramp at SAT and facing a FSDO inspector who is a little bit tired of cowboys hauling saddles in the empty backs of their 170's and no documentation other than their claim of a scribbled little note in a logbook they also claim is in the hangar "back home"... and feels it behooves himself and all of general aviation to make an example of somebody!

The point is: I don't necessarily LIKE the answers I must give. But I feel compelled when asked such questions to research the question and provide the BEST answer I can, which will apply in ALL cases, and which comply with the regulations and law. Now it just so happens I have personal knowlege of this specific matter and how at least one FSDO regards the matter. They explained it to me just like I am relating it here. I am quite confident that even an inspector at ANC who smells like whale blubber and hunts in a Super Cub with a kayak and a harpoon lashed to the struts will accept a 170 whose rear seat removal was documented with a Form 337 that all those kooks down in the lower-48 FSDO's think is necessary for flight. In other words, it is the "most correct" answer that I can provide that I know will pass muster.

Do I think it is overkill? Yes and No. But although it's a pain in the patootie, it's the right answer. What anyone does with this information is entirely up to them, but don't get in trouble with an inspector and come back here and complain that I didn't give you the correct answer.

PS- I took my back seat out when I flew up to Mena, AR so Dell could install my bag door. I didn't want it in his way and I didn't know at the time how careful he is with customer's airplanes and I didn't want to risk his damaging my uplholstery removing it. (Plus I wanted to modify it with quick-release pins at the hinged-back while it was out. Yes, that is documented.) My airplane has so many 337's in it's records that I can never carry all the documentation aboard the airplane,... one of them allows various combinations of seats to be installed or removed for flight. The irony is.... if and when I'm ever ramp-checked my records won't be available simply due to their needless weight.... they'll be at home where they belong! But the fact is, aircraft work and mods are not complete until the paperwork is finished. I carry an Equipment List that reflects the aircraft configuration, as required by FARs. I recommend anyone who plans to remove their original seat and fly the airplane in that configuration have that major alteration documented on the proper FAA Form 337. It's only a piece of paper, but it'll keep you out of trouble with any FSDO,... and you won't have wasted your insurance premium when it comes time to make a claim and the accident investigator notices you have a basic piece of equipment missing.

Cessna also had photos showing stretcher patients and nurses in an ambulance modification. Since that modification was a factory configuration, ... IF the owner purchased that configuration ... THEN that configuration would be legal. YOU don't have that configuration in your aircraft and YOU cannot perform that alteration on your own, without a Form 337.

A slight bit off the topic but my good buddy Leroy's 170A did come with this stretcher option according to his paperwork. I've yet to see it installed.

So he has the opposite problem in that he needs paperwork to install his passenger and rear seat.

Ok so what is the basis for the approval of your field approval?

"mod cessna" I see nothing correct in your last post, beginning with the reference to a document which does not exist for a Cessna 170..... (poh). The other examples you give are not germane, as they are different aircraft and Cessna marketing photos. If marketing information were certified we'd all be making 145 hp on takeoff.

The only reference i made to a 170 poh is that i do not have one to look for examples in. Ok 170 owners manual.
The examples i did give are completely relevant. Yes they are different aircraft but very similar. Cessna single engine type certified for four people. Where did you get the idea that an owners manual and a POH are just marketing info?


Ok gahorn lets say it is a major alteration to remove a rear seat. What approved data would the IA use on this 337? Your IA can not use a STC because there is no STC for rear seat removal. By your account you would need a field approval since there is apparently no approved data to remove a rear seat. A 337 requires approved data.

By the way everyone it does not matter if you are in Alaska or Florida removing the rear seat is NOT A MAJOR ALTERATION.

gahorn wrote: ............I am quite confident that even an inspector at ANC who smells like whale blubber and hunts in a Super Cub with a kayak and a harpoon lashed to the struts........

OK George, one more time, we've been thru this before............................................where in the heck is ANC?

George is just the canary in the coal mine a lot of the time, even if he doesn't agree with it he's seen what HIS FAA office wants and reports same to us. But, each FAA office is their own little kingdom, they can decide to enforce or interpret what they want. sometimes that depends on whomever went to school lately in OK City and got another part of their brain removed. IMHO

for what it's worth, up here in ND our friendly Feds don't seem to care what combination of seats is in the airplane, as long as there is an updated W&B reflecting the current configuration. We operate our work airplanes with most of the seats removed in various configurations depending on what combination of special equipment we have installed - when we do that, they're in Restricted category, but the seat configuration isn't specified in the 337's for the weather or research equipment. I write those as vaguely as possible to give us as many options as I can, and we NEVER include what seats might be installed.

We also run Normal category airplanes (all of ours are Multiple Cat - Normal or Restricted depending on whether any special equipment is installed) with some seat out, for instance a C340 is much better with the LH rear seat out by the door for access and room, and our local Feds happily rent that very airplane from us for currency and don't pay any mind to what seats are in it - as long as the W&B is updated. If I was going to pick up a half of beef from my in-lawsacross the state in my 172, I'd be perfectly legal UP HERE with the back seat out and an updated W&B reflecting that, and in fact I've done that many times. BUT, that's in my little FAA world, yours may be different and you should make polite and discreet inquiries to find out what you can get away with.

I wish I could say all that quicker but I only have to do it once I guess