Odd question regarding fast boats and SEATS

jaysmiths · Aug 15, 2012

Don't have a boat anymore but am building an experimental airplane and have two nice looking Tempress seats to install soon.

The dealer that sold these boat seats (a few years ago) told me there is some standard that they are manufactured by as far as holding up to acceleration--not good if the seat back gives way and you flip over backward while yanking skiers out; doubly bad when firewalling the throttle during take-off in an airplane....

My airplane will have to be inspected by an FAA rep and the question is likely to come up: How do I know these seats will hold up to normal takeoff acceleration? Well, right now, I don't know!

The seats are Tempress brand; once I owned a 22' aluminum boat with a 235 Johnson outboard and I'd guestimate that a holeshot in it roughly approximated a takeoff roll in a Cessna 172 but certainly don't have empirical data.

Anybody know anything about this that might be helpful to me? I call always fab some reinforcement "to be sure" but if it's not necessary that would sure save some time and weight.

Thanks in advance for anything that might shed some light.

Fireman431 · Aug 15, 2012

Re: Odd question regarding fast boats and SEATS

Your marine seats are not acceptable in an aircraft. FAA has very strict rules regarding the types of seating, brackets, foam, and upholstery (especially flame retardancy) for aircraft use.

Here is a link to the FAA/CFR flammability requirements:
http://www.fire.tc.faa.gov/pdf/25-853.pdf

UncleWillie · Aug 15, 2012

Re: Odd question regarding fast boats and SEATS

jaysmiths said:
... am building an experimental airplane...

It is an EXPERIMENTAL Class Aircraft.
You can put in lawn chairs if you want.
The inspector will grab them and give the a good shove if they look flimsy.
If the inspector decides that they are Airworthy then they ARE Airworthy.

The seat will need to take more than takeoff acceleration.
They should handle the category loads of a few g's and crash loads of at least 10 g's
Sit in the seat, put your feet on the dash, and push with all you've got.
They should stay in place!

"Experimental" has a lot of wiggle room for improvising. You just need to convince the inspector.

Are the seats ABYC Class A driver Seats?

Bondo · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

jaysmiths said:
Don't have a boat anymore but am building an experimental airplane and have two nice looking Tempress seats to install soon.

The dealer that sold these boat seats (a few years ago) told me there is some standard that they are manufactured by as far as holding up to acceleration--not good if the seat back gives way and you flip over backward while yanking skiers out; doubly bad when firewalling the throttle during take-off in an airplane....

My airplane will have to be inspected by an FAA rep and the question is likely to come up: How do I know these seats will hold up to normal takeoff acceleration? Well, right now, I don't know!

The seats are Tempress brand; once I owned a 22' aluminum boat with a 235 Johnson outboard and I'd guestimate that a holeshot in it roughly approximated a takeoff roll in a Cessna 172 but certainly don't have empirical data.

Anybody know anything about this that might be helpful to me? I call always fab some reinforcement "to be sure" but if it's not necessary that would sure save some time and weight.

Thanks in advance for anything that might shed some light.

Ayuh,.... Boat parts aren't documented parts like aircraft parts are....

jaysmiths · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

Experimental aircraft are exempt from the Federal Aviation Regulations cited above but during the required inspection
"airworthiness" in the inspector's view is determined---there are some basic guidelines but few hard and fast rules for experimentals.

The dealer (now gone) who sold me the Tempress seats and I discussed this at the time of purchase. He seemed knowledgeable and stated that there is a standard for strength against acceleration that the boat seats met; after all, he said, there are some boats out there with twin 454s that accelerate pretty hard. In searching for these standards referred to, I've come up empty but it indeed seems reasonable to me that makers of high performance boats would only buy seats that met some kind of standards.

I was hoping that someone on here would be familiar with those standards--if there are any.

jaysmiths · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

UncleWillie: The ABCY Class A link you included may be what I was looking for, I'm investigating.

Thanks much.

H20Rat · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

I'd say a boat seat that can stand up to pounding waves for hours at a time without falling apart will laugh at acceleration forces. I've been in conditions that will nearly shatter your spine, but the boat seats generally held up. Small airplanes can be rough, but they don't compare to what a boat can go through.

I'd be more worried about making sure the cushions are firmly attached. In a boat, they often aren't held in very well, and if you are alone in a 2 seater airplane, and hit some turbulence, the last thing you want is the passenger cushion flying into your head. (worse yet, boat cushions are often meant to be removable.)

Scott Danforth · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

In an aircraft you want everything to be strong and lite. boat seats are not lite by any means.

being experimental, you could use them, however I would rather have a carbon fiber or aluminum racing bucket with a leather or cloth pad and SFI approved 5-point harness. with the two seats, that should be a significant weight savings over the boat seats

haulnazz15 · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

Agreed, in the experimental class, you can use whatever you want if it is deemed sufficient. There is no "documentation of parts" per say, like there is with mass-produced aircraft. But as Scott mentioned, the weight penalty of marine seats would be significant. A lot of work goes into most aircraft seating to make them as light as possible while still maintaining rigidity and durability.

ssobol · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

The key factor in aircraft seats is deceleration capability, not acceleration. The seat needs to protect the occupant in the case of a hard landing or crash. Unlike cars, aircraft seat belts are most often attached to the seat not the body of the vehicle. The seat is attached firmly to the airframe. The seat must stay attached and intact if the aircraft crashes. For seats used in transport category aircraft the seat must be able to withstand a vertical deceleration of 16g's holding the average passenger (say 200#). There are also likely requirements for lateral and longitudinal accelerations.

In experimental aircraft you can do whatever you can convince the inspector to approve. However, I would think that boat seats are not strong enough as they are not designed with this application in mind.

You might be better off getting some car seats (e.g. Recaro). There are requirements for crash worthiness on car seats. Considering the wide variety of boat seat styles, I would doubt that there are similar requirements for boat seats.

Fireman431 · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

UncleWillie said:
It is an EXPERIMENTAL Class Aircraft.
You can put in lawn chairs if you want.

You can put lawn chairs in a boat as well, but just because you can doesn't make it a good idea.

V153 · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

Fireman431 said:
You can put lawn chairs in a boat as well, but just because you can doesn't make it a good idea.

Certainly not. Beach chairs are what ya use in a boat ...

UncleWillie · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

Fireman431 said:
You can put lawn chairs in a boat as well, but just because you can doesn't make it a good idea.

It doesn't make it a bad idea either!

4130 Chrome Molly Tubing laced with seat belt webbing would make one heck of a strong lawn chair.
And a darn good and light aircraft seat if designed well.

Plain old Wallymart lawn chairs would suffice, bolted to a 20 ft. party barge with a 9 hp motor.

It all depends on the application!

CoffeeHound · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

V153 said:
Certainly not. Beach chairs are what ya use in a boat ...

Good one !! But not in my boat , they will be tied down on the front work deck.
Passanger(s) seated near the cockpit, a few even pray for seatbelts.

V153 · Aug 16, 2012

Re: Odd question regarding fast boats and SEATS

Actual ad ...

jaysmiths · Aug 17, 2012

Re: Odd question regarding fast boats and SEATS

Wonderful discussion and information, I appreciate it.

The seats I bought are reasonably light for the comfort level--racing seats as suggested would not be comfortable in a 3-4 hour flight so that nixed them. Some builders of the BD-4 have used auto seats from smaller cars, one builder weighed his seat (from Suzuki Samurai) and they came in at 11 apiece or so, the boat seats weigh 8 each, additionally the fabrication of mounts for them is much simpler than for automotive buckets.

Hmm, what to do, what to do...

Thanks again for all the information. Here is the airplane and seats in question.

metriccrescentwrench · Aug 17, 2012

Re: Odd question regarding fast boats and SEATS

jaysmiths said:
Hmm, what to do, what to do...

While I was building a Cozy I found that I got the best support from the online Cozy builders forum. I'd imagine you probably have a similar resource available. Also, have you been in contact with an EAA Tech Counselor? Look one up in your area, preferably one who has experience with a plane like yours. And it wouldn't hurt to look up whomever is going to be doing your airworthiness inspection (either an FAA inspector from your FSDO or a DAR) and ask if they'll approve whatever seats you have in mind. Also, are you a member of a local EAA chapter? I'd imagine they've got some very experienced builders that can give you good advice.

haulnazz15 · Aug 17, 2012

Re: Odd question regarding fast boats and SEATS

I guess I have to ask . . . why not just find some seats from a boneyard Cessna/Piper/Bonanza?

jaysmiths · Aug 17, 2012

Re: Odd question regarding fast boats and SEATS

haulnazz15 said:
I guess I have to ask . . . why not just find some seats from a boneyard Cessna/Piper/Bonanza?

Those boneyard Cessnas etc are 40-50 years old; the seats were not very elegant even when new and many older airplanes have semi-collapsed bottom seats......

haulnazz15 · Aug 17, 2012

Re: Odd question regarding fast boats and SEATS

jaysmiths said:
Those boneyard Cessnas etc are 40-50 years old; the seats were not very elegant even when new and many older airplanes have semi-collapsed bottom seats......

The frame is the important part, I'm not sure that age is really too much of a factor. Seats can always be reupholstered to add comfort. I would really have to pass on those marine seats.

Odd question regarding fast boats and SEATS

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