The Ideal Flying Boat?

[MrWidgeon]

That "Quota" is a pain in the .... neck, you have to use a photo hosting service like Photobucket.
I would like to see your sketch though.

Bill

[Adventureguy]

Your imagination might be better than my sketch. It's a lot like a Savoia Marchetti S.XX (i.e. S.55, S66 etc.) The main differences, besides smaller scale, are:
1. A single, tractor engine overhangs forward from a stubby pylon with a clear nose wide enough for the pilot's head, so the cockpit is, from the inside, somewhat similar to the Gee Bee racing plane (although with the pilot's shoulders and body in the wing, rather than in the fuselage.)
2. The airfoil in the center is as thick as possible, percentage wise (meaning 20% or thereabouts.)
3. The tail is, as mentioned above, an inverted U, with the usual fixed stabilizers and moving elevator and rudders.
4. The twin hulls blend smoothly into the two vertical tails without connecting truss-work.

The engine is the most difficult problem. The one that looks the most attractive in reliability, fuel efficiency, and price is the Japanese HKS twin. Unfortunately, it seems too heavy for a US Ultralight, using fully half the weight allowance, and it seems underpowered for the single engine of a Light-Sport Aircraft flying boat. If I must build the engine as well as the plane, then don't look for me on the forum for a while...

[Adventureguy]

Back to this topic...

Thorough investigation shows that a multi-engine flying boat is right out for most people, at least for the time being. This is partly due to the nature of contemporary twin-engine aircraft: yawing, half power with one engine out, and zero power if the wrong throttle is pulled during an incident. The latest propulsion technology can solve all of this rather easily, but convincing aviation authorities "problem solved" appears excessively difficult and expensive.

Limiting the field to single engine boats, it seems to me that the SAIA Marchetti FN333 Riviera is the best inspiration for a new design for enthusiasts, and that the main points in favor of building new would be:
- a less expensive engine: either a 5.9L (360 cu.in.) four-cylinder aircraft engine or a 6L automotive engine,
- primarily low-upkeep composite construction,
- improved, deep-compound-curved hull design made practical by composite construction,
- narrower tail and folding wings enabling road transport without special permits.
(What is the UK width limit for that last one, by the way? For most of us "colonials" it seems to be 2.6m.)

...unless something new and radically different would be more worthy of the attention of able flying boat enthusiasts...

Adventureguy

Happy Easter to all!

[achean]

Wow, nearly four years since the topic started and I can remember joining it back near the start. How time flies. FWIW, since starting this thread I've got my PPL and done several aircraft design courses. I really should log in more often...

Getting a flying boat design through the UK is going to be a tricky task, if that's what you were thinking.For a homebuild kit, you'd have to go through the Light Aircraft Association's Engineering department to get approval and they are much more stringent than just about anybody else apart from EASA (the European certification authority.) EASA charge €250,000 per year to certify a new design while the design work is ongoing. Robinson spent years and over $6m getting the R66 certified.

Were you thinking of an Experimental design for the US? Whatever you go for, single engine is a prerequisite for a serious contender in the market. Multi engine aircraft are too expensive to produce, although the Aircam seems to have a bit of a following. The Icon A5 is another market entrant, but that failed to make the LSA weight limit and had to have an exception to be certified within the LSA rules (partly due to incorporating a ballistic recovery system.)

How's your thinking developing?

[Adventureguy]

The real problem with flying boats seems to be economic, not technical, at least for someone such as myself with technical skill but only moderately good income.

I read the postings from Chris (AKA dogsbody) regarding the fires with special interest after seeing the movie made by my neighbor's brother as he escaped from his burning small town with only his life and his phone. As he and his buddy drove away, the pickup truck just ahead of them in the evacuation drew a burning ember into its air cleaner and caught fire, so those people had to be hurriedly crammed into other vehicles.

That disaster and the advert for flying the Mars make me wonder if there might be an economic case for flying boats that are normally recreational craft but can be pressed into service as water bombers when needed. The government might provide some relief from the normal expenses, especially aircraft taxes, insurance, and landing and storage fees at government airports in exchange for the right to priority use of the aircraft during disasters.

One question that comes to mind, though, is: How effective are water bombers? Do they pay for themselves during wildfires?

Adventureguy

[dogsbody]

The real problem with flying boats seems to be economic, not technical, at least for someone such as myself with technical skill but only moderately good income.

I read the postings from Chris (AKA dogsbody) regarding the fires with special interest after seeing the movie made by my neighbor's brother as he escaped from his burning small town with only his life and his phone. As he and his buddy drove away, the pickup truck just ahead of them in the evacuation drew a burning ember into its air cleaner and caught fire, so those people had to be hurriedly crammed into other vehicles.

That disaster and the advert for flying the Mars make me wonder if there might be an economic case for flying boats that are normally recreational craft but can be pressed into service as water bombers when needed. The government might provide some relief from the normal expenses, especially aircraft taxes, insurance, and landing and storage fees at government airports in exchange for the right to priority use of the aircraft during disasters.

One question that comes to mind, though, is: How effective are water bombers? Do they pay for themselves during wildfires?

Adventureguy

A good idea but would not the pilots need some extra training to be qualified to do water drops? Would that be up to the government to fund that or left to the pilots themselves?


Chris

[MrWidgeon]

A recreational sized flying boat or amphibian is too small to deliver much water and the expertise needed to drop accurately is developed over time and many hours of practice.
There's no market for something the size of the Mars as a passenger type in the commercial arena and it takes a large crew to operate it, both in the air and on the land or water.
Not really feasible I'm afraid.

[Adventureguy]

Chris,

I think the answer to your question is in your signature. One thing pilots are not supposed to do normally is to bomb things, so who wouldn't sign up to do so?

Nowadays, it would seem relatively easy to build marvelous thermal bomb-sights, the envy of any B-17 or B-52, to considerably shorten the training time for dropping water on fires accurately, and only on fires or practice flares.

Also, with the advantage of 70 years of progress, most of the crew requirements for large aircraft have been automated away. Cargo planes don't really require any crew, and one might even argue that for fire-fighting planes should take all of the risk by themselves!

But I concede to Mr. Wigeon the point about needing a large plane with too few other good uses to drop a significant amount of water at a time.

I wonder, though, if recreational-sized flying boats can carry a significant amount of ground equipment for fire-fighting, such as pumps and hoses, to land on lakes.

Adventureguy

[dogsbody]

One of the problems that arose during the wildfires here in May, was the large number of aircraft being used to fight the fires. It made air traffic control difficult. The last thing you would want to add to that is inexperienced pilots joining the fray.


Chris