USA FAR 103 Seaplane Riddle ?

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scottperk

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I dont think very many have ever figured out just what a jewel the FAA gave
the USA in that they took the regular 254 pound weight limit and 25 pound
parachute allowance and added a 30 pound allowance for a hull and two
10 pound allowances for sponsons.

Specifically there are some pusher ultralights that without a lot of trouble
or a lot of extra weight could convert the fuselage to a floating hull shape.
Further, if a flyer were willing to give up land operations I think on average
by removing their landing gear they could get back 25 pounds or more for a pure
seaplane operational mode. So lets assume you use ping pong balls for sponsons
you now have 50 pounds to convert/add a hull to your plane and 25 more pounds to increase the size of your motor and still be legal. Now this is of course a
simplification because you would want to use some of your allowance to also
strengthen the rest of the airplane so not all would go to motor and hull
but that increases the empty weight from 254 plus 50(hull) plus 25( wheels/axles)
plus 25 ( parachute ) to create a very substantial aircraft way moreso than
the commonly thought of 254 pound USA ultralight.
Essentially now 354 pounds!

What I call a best kept secret and probably the best deal in the world
yet only a hand full have ever taken advantage of this FAA generosity.

Specifically the riddle is what is the best design approach to creating
the best seaplane and whether to convert an existing design or
start from scratch and build a seaplane. The best hints and clues are
obtained by looking at what others have done in the last 35 years
 

BBerson

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If you install two float pontoons, (let's say only for emergency use) how big do they need to be?
 

12notes

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Would you save any weight using inflatable floats? Or do those end up being heavier than other types?
 

scottperk

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If typical pontoons are used as in ordinary float planes the FAA allows 30 pounds
each for two floats. This option I do not think to be as good as the hull based
fuselage as it is very difficult to make a float that weighs only 30 pounds.
Bear in mind once again that by converting to pure seaplane, you also get to
remove the landing gear and that weight savings can help very much.
Strangely, the very heavy duty inflatable floats as sold by Lotus Floats
are heavier than aluminum or composite floats. Same with the inflatable
boats used by the Trike guys.... I doubt you could find a boat that only
weighs fifty pounds to match the allowance.

With some great imagination I have thought it might be possible to use
super light and fragile inflatable flotation with a water ski or two protuding
down much lower to take the pounding of the water and only when the
plane is going very slow would it settle into the water thereby not exposing
the fragile floatation to abuse. Those familiar with the AquaGlider will remember
two water skis used to take the water pounding.

in order to not trick the FAA by taking a land plane and adding some innertubes
for floatation just to get the weight allowances.... The FAA requires that the
plane be able to take off from and land on water.

I have been playing with the new Google Photos and following this link are several ultralights in album form that I believe to be the best ultralights for conversion to FAR-103 Seaplanes

https://photos.google.com/album/AF1QipNr6vGn3x04cQPBfXw4BU3Bui4tTiIkrRGQRow
 

BBerson

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Pop out floats isn't gaming the system. The FAA encourages devises to be deployed in an emergency.
But I don't think the FAA is checking weight now anyway. There seems to be effort from the FAA to relax the rules or stretch them. I just heard the FAA issued a STC to EAA and Dynon for use in certified aircraft. A new way around the rules.

From AC103-7 -
18 0 POVEREVDEHICLEWEIGHT.
a. Items Excluded From the Computation of the Empty Weight of a Powered
Ultralisht Vehicle.
(1) Safety Devices Which are Intended for Deployment in a Potentially l.
-m -
Catastrophic Smon. Parachutes and some associated addltional equipment
8
Par 16
 

Riggerrob

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Many helicopters already have TSOed pop-out, emergency floatation bags bolted to their skids or lower fuselage.

However, I am more interested in precise weights of the inflate able hulls hanging under weight-shift ultralights because my long-term goal is to design a two-seater seaplane with an inflatable hull similar to a Zodiac. A Zodiac style hull will hopefully provide enough lateral stability - far enough outboard - that allows us to forget about tip floats. OTOH the hull cannot exceed the 8 foot width of a common trailer, because I want to be able to launch it from the nearest municipal boat ramp.

The center hull will be made of fibreglas and vaguely resemble the V-hulls on fast Rigid Inflateable Boats used by special forces soldiers when they trespass without permission of the host nation ...... err forget their passports.
Yeah!
That's it .... they forgot their passports.
Hah!
Hah!

However, on closer examination, the center hull will
look more like the skis under old Dornier flying boats.

Finally; the lighter the better, because we still want to get decent performance with a 100 horsepower Rotax and want to stay within LSA weight limits: 1,250 or 1,350 pounds.

Does anyone have precise weights for the inflatable hulls hanging under weight-shift ultralight flying boats?
 
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Aerowerx

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Are you sure about that parachute idea?

I would be really surprised if they allowed you an extra 25 pounds for NOT having one.

I also question the idea of having extra weight with a floating hull, when the regs specifically say "pontoons". That's like the guy who proposed a 3 inch diameter fuel line to get around the 5 gallon limit.
 

BBerson

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When has the FAA ever checked the weight of an ultralight? Never happened to my knowledge.
Yeh, that's my point, why bother adding fake floats or whatever.
However, if a manufacturer could convince the FAA to approve some scheme like ICON did, then they would have a marketing advantage because the most powerful and heaviest aircraft sells best.
The operator is responsible for the weight, not the manufacturer. But it would be nice for the manufacturer to push the limit as much as possible with FAA approval. Much like Carbon Cub has FAA approval with absurd pushing of the Light Sport intent.
 

Aesquire

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The FAA will check the weight of your Ultralight if you annoy them in any way.

Or when they feel like it. Whichever comes first. I don't know personally anyone who got weighed in this century. In the 1990's? a few.

You get an allowance for carrying a chute. Some, maybe most, but not all ballistic chutes mass less than the allowance, so usually you can then add mass for other things and stay legal. Usually that spare weight allowance is used for brakes. If you don't have the Chute you don't get the allowance and 254 is it.

One of the few aspects of pt 103 that is usually "ignored" is top speed. If you pass an FAA guy, or a jerk, in his Piper Cub that's already doing 65 mph, then Yes, you will get a nasty visit. The normal pt 103 top speed limit of...., what was it in Hectares per Fortnight again? Does not apply to helicopters or gliders.

but you can make a very nice amphibian with careful design and no need to "cheat".

Connie ultralight, Connie amphibious ultralight, Moyes Microlites Connie amphibious single seat part 103 ultralight aircraft, Ultralight News newsmagazine.
 

radfordc

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The FAA will check the weight of your Ultralight if you annoy them in any way.

Or when they feel like it. Whichever comes first. I don't know personally anyone who got weighed in this century. In the 1990's? a few.
[/URL]
Once again you're sure that the FAA does it (checks UL weight) but you can't cite any actual instance. Pretty much the same "myth" that gets told any time ULs are discussed. I would just once like to hear the actual details of it happening.

As far as "annoying" the FAA...I did that one day while flying my old Quicksilver MX (which weighted over 254 lbs) and they didn't even say "boo". I landed at a local air show just after the airport was closed by the NOTAM. As I taxied up one of the plane spotters said that the FAA needed to talk to me. When I met the FAA guy he said don't do that again.
 

Aerowerx

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Once again you're sure that the FAA does it (checks UL weight) but you can't cite any actual instance.....
But, the point is that they could do it. At any time and any place.

If you want to risk it, go ahead. But don't cry when everyone else hates you for getting part 103 revoked.
 

scottperk

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Are you sure about that parachute idea?

I would be really surprised if they allowed you an extra 25 pounds for NOT having one.

I also question the idea of having extra weight with a floating hull, when the regs specifically say "pontoons".
I am absolutely certain about the parachute allowance but I was vague. The allowance is
25 pounds at a weigh in without you having to weigh your chute separately.... but you DO
have to have a chute. So the benefit comes if you have a hand deployable chute that
weighs actually 15 pounds and then you would have a net 10 pound "benefit"
in structural weight somewhere else.

There was more than one addendum to the original FAR103 UL guidelines and two of them
dealt with seaplane or waterborn operations.... In terms of not having to weigh separately
you have the choice of two "pontoons" of 30 lb ea ( 60 tot) OR a hull based fuselage ( 30 lbs)
with two sponsons (10lb each). I dont know where or why you think following the rules
to the letter is gaming the system ? ? ? Maybe everyone is in love with the LSA guidelines
but I happen to think the FAR 103 Seaplane guidelines are the very best opportunity.

About weighing ultralights by the FAA as incentive to be legal.
The biggest incentive to not be illegal is when something bad happens like
a crash or injury yourself or to another person or property. No body's
insurance will cover an illegal activity. The FAA will gather components
in a crash and weigh them all separately or an insurance company might
under the direction of local law enforcement authorities if something bad
happens and the FAA especially if negative news was generated will
revel in being able to say an unlicensed pilot was performing an illegal act
in an unlicensed airplane way beyond their ability to manage and monitor
and disavow any and all responsibility.
I fully concur that you could fly for a long time in a FAT, fast and over fueled
UL type plane without N numbers or pilots license and forever get away with it
........ UNTIL something bad happens. In that situation be sure to not waste
any money on insurance for your plane or liability for your activities as the insurance
company will NOT cover any event.

I knew a guy in a local UL club whose FAT UL engine cut out over a popular lake
( govt controlled ) and was charged/fined with several illegal activities after his plane
was recovered by authorities and weighed after consultation with the FAA and
after being featured on the evening news with TV coverage and interviews of
witnesses etc etc. Some of the charges were related to illegal boating activity
since it was motorized and in the water etc.

in prohibited airspace
 

radfordc

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I knew a guy in a local UL club whose FAT UL engine cut out over a popular lake
( govt controlled ) and was charged/fined with several illegal activities after his plane
was recovered by authorities and weighed after consultation with the FAA and
after being featured on the evening news with TV coverage and interviews of
witnesses etc etc. Some of the charges were related to illegal boating activity
since it was motorized and in the water etc.

in prohibited airspace
Maybe the only thing consistent about FAA enforcement of ULs is inconsistency. My friend Tom had a fat two place UL (not an exempted trainer). He was doing a candy drop for a bunch of kids and managed to bump the master switch off and ended up in the top of a tree. He made the 6:00 news and the FAA came calling. He was given a 6 month suspension of his PPL and had to do some special training. No other fines or penalties.
 

choppergirl

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Don't forget, if you overly-game the system and get the rules changed to be more restrictive, you're going to be one very unpopular individual within the 103 community. Plus you'll be on the FAA radar for your future activities. Let's all play nice in the sandbox.
These guys absolutely destroyed the reputation of remote piloted aircraft, and I have yet to cross a thread 'round 'cheer of anyone *****in 'bout them. Where is the FAA? Where is the sandbox? They drove their monster trucks through the sandbox...
 
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scottperk

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OK. so it is established we have a 314 pound empty weight budget.
As a suggestion lets say we start with the Ritz Std UL that weighs 200
pounds with a 22hp motor and taildragger landing gear.
Since we are targeting pure seaplane ops we remove 20 pounds of axles
and wheels placing our new starting weight at 180 pounds.

314 minus 180 = 134 pounds we have to work with to convert the hull
into a waterproof hull and strengthen the entire structure to handle
additional pounding of water takeoffs and landings and the ability to
carry the increased gross weight with safety cushion margins.

There are just a handful of other UL models that I think could provide
a jumping off point as nice as the Ritz Std. Hey, with 134 pounds to
play with I'd expect we would get a more powerful engine as well.%Ritz-std-A Drawing.jpg%ritz4-open fuse.jpg%ritz1-show.JPG
 
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