What if we start a group design for a new fire-fighting airplane?

[Archibald]

Travelling from France to Altea (spanish coast between Valence and Alicante) from the highway I glimpsed some Air Tractors configured for fire fighting - with floats. Didn't knew there was an Air Tractor company in Spain.

https://airtractor.com/dealers/air-tractor-europe/

Air Tractors on floats certainly look the part : straight out of Porco Rosso.

 

[Foo Fighter]

I must confess that obfuscation and complication have been the enemy to more projects than I care to think of and prefer the KISS standard.

There are numerous options here but frankly, the smaller water based aircraft along with rotary support for variation of risk/location, seems best. One airframe/type seems to be a dead end. Missing the actual requirement at both ends.

Whether you choose manned/autonomous/optional is pretty much irrelevant for me, a force which is adaptable to different locales seems to be much more important.

 

[Apophenia]

... prefer the KISS standard... but frankly, the smaller water based aircraft along with rotary support for variation of risk/location, seems best...

Okay, but geography and distance are major factors in making such a choice. I'm guessing that you live on a compact island located off the NW coast of Europe?

If so, the UK's largest forest (Galloway) covers something like 77.7k hectares. England's largest forest (Kielder) covers just over 60k. As for wildfires, AFAIK, the last major UK event was a 2022 grass fire outside London that destroyed 20 houses. Tragic though that was, contrast it with non-British locations.

The 2019-20 Aussie bushfires burnt 12.6 million hectares of forests/woodlands with another 4.6 million hectares of grassland (so 245 times the scale of Britain's largest forest). Amazingly, only 33 Australians were killed in those fires (although animal losses are estimated at over 3 billion). I've already mentioned the loss of 520 buildings in Lytton, BC, in 2021.

Going back to physical scale, British Columbia's Great Bear - entirely made up of rare temperate rainforest - measures 6.4 million hectares. And even that pales compared to the near Canada-wide boreal zone whose forest cover 552 million hectares (for comparison, Russia's boreal forests cover only 190 million hectares). The distances that need to be flown are staggering.

My point here is that there are reasons for the larger scale of airtankers outside of Europe. As Scott Kenny has noted, there are very practical reasons for both waterbombing helicopters and SEATs. And neither are at any disadvantage over shorter distances. Where longer distance dictate rapid transit times, their major advantage is cost-reduction. That's why the Gov't of BC found itself trying to publicly square its KISS 'money-saving' budget targets with an entire town being burned to the ground.

 

[Scott Kenny]

I must confess that obfuscation and complication have been the enemy to more projects than I care to think of and prefer the KISS standard.

There are numerous options here but frankly, the smaller water based aircraft along with rotary support for variation of risk/location, seems best. One airframe/type seems to be a dead end. Missing the actual requirement at both ends.

Whether you choose manned/autonomous/optional is pretty much irrelevant for me, a force which is adaptable to different locales seems to be much more important.

Too small for wildfires outside the UK.

The western US just had a big fire season (still going, technically, we've had new fires started since September 1st). Oregon alone has seen 643,000ha burned. California has burned 400,000ha. Washington (state) and Idaho don't have totals burned on the Wiki page. Nevada hasn't been too bad, a handful of small fires, but they're also more grasslands or desert, easier to get a fire started in dry grass but also easy to have natural fire breaks.

Oh, and Idaho has one fire that has simply been left to burn itself out because there aren't any crews available to fight it with everything else on fire. Called the Wye fire, 12,857 acres burned, ~5000ha.

Per the NIFC website, the total acreage burned for the US in 2024 is 7,329,660, just under 3 million hectares.

That's where you need BIG fire bombers. High capacity, reasonably fast, and usually moderately ranged. When the plane has to return to an airfield after every water drop and spend however long it takes to reload the water, adding fuel at the same time is trivial. It's more a matter that any plane that has the payload ends up being long ranged, so they deliberately load minimum fuel and load water to MTOW.

 

[Foo Fighter]

Pardon me, I did not get my point across at all well.

By 'smaller' aircraft, I am talking about the water borner fixed wing aircraft you have mentioned. In addition to more localised rotary wing coverage.

I suppose it is going to come down to what exactly the management are willing to fund the project and how well these aircraft can be global resources. feeding a need in different global threat areas and making the funding easier to achieve. If different parts of the globe can use larger resources at different times of the year/season it is going to bring costs down.

Twin engined seaplanes are not exactly common but are there, as is the Japanese four engined type.

Martin Mars types would be nice to have but not really going to happen as I see it.

 

[Scott Kenny]

Pardon me, I did not get my point across at all well.

By 'smaller' aircraft, I am talking about the water borner fixed wing aircraft you have mentioned. In addition to more localised rotary wing coverage.

I suppose it is going to come down to what exactly the management are willing to fund the project and how well these aircraft can be global resources. feeding a need in different global threat areas and making the funding easier to achieve. If different parts of the globe can use larger resources at different times of the year/season it is going to bring costs down.

Twin engined seaplanes are not exactly common but are there, as is the Japanese four engined type.

Martin Mars types would be nice to have but not really going to happen as I see it.

As regards the rotary wing coverage, the major problem is that other agencies tend to not have helicopters with enough lift capacity to haul a loaded Bambi Bucket. When everyone was flying surplus Hueys it was fine, but as those got replaced with cheaper to operate helicopters their sling load capacity went way down. Bo105s or Bell JetRangers don't have the MTOW/sling load capacity to handle a Bambi Bucket at all, for example. So "external agencies" would need to be forced to buy bigger helicopters than they generally need to have those available for firefighting. Obvious exception for military, but that requires specific permission in the US. It's usually given pretty quickly, but it has to be requested.

Again, scooping planes are limited in where they can work from. There are many lakes, reservoirs, and rivers where I live. Most of them are inaccessible to even AT802 Fire Boss, nevermind the bigger scoopers like a CL415/515 or the big Beriev Be-200 Altair. Too twisty, trees at the ends too tall to drop in, get a load, and climb clear at the end.

The big scoopers are best used on oceans or the REALLY BIG lakes, the kind you can see with the naked eye from orbit. And that's generally a long way away from where the big fires are in the US. The Great Lakes are closer to much of the eastern Canadian forests (not sure about proper name), and the ocean is close to the western Canadian forests. Not ideal due to salt content, but a single drop isn't dangerous to the plants.

Honestly, what would be ideal is someone with Musk/Bezos money to start up an aerial firefighting company and have them contract out across the planet. And they'd just travel between Northern and Southern hemispheres chasing the fires. Yes, a private company and not government. Because it's a lot easier for a government to contract a company than another government.

 

[Apophenia]

... it is going to come down to what exactly the management are willing to fund the project and how well these aircraft can be global resources. feeding a need in different global threat areas and making the funding easier to achieve. If different parts of the globe can use larger resources at different times of the year/season it is going to bring costs down.

Twin engined seaplanes are not exactly common but are there, as is the Japanese four engined type.

Martin Mars types would be nice to have but not really going to happen as I see it.

You are basically describing the seasonal exchange of airtankers between hemisphere which has existed for decades. The only way to improve it would be to establish uniform, global standards that everyone can both agree on and be willing to fund. Can't see that happening, can you?

"Common" is the key requirement for the affordable procurement of new waterbombing platforms. That too is in short supply.

Much as I love the literally awesome Martin Mars, their actual utility was quite limited. (Those huge boats were moored on 25 km-long Sproat Lake for a reason.) Back in the day, Dan McIvor recognized value in the Mars (along with vast stocks of spares) being sold for scrap value. We won't see those kind of opportunities again.

 

[Apophenia]

As regards the rotary wing coverage, the major problem is that other agencies tend to not have helicopters with enough lift capacity to haul a loaded Bambi Bucket...

Yup. There is an endless push-me/pull-you on size for airtankers.

On the bigger end, governments (with citizen support) demand more economy from contractors. Those contractors try different ways of cutting their overheads until the sole option left is smaller platforms. There is a moment when the fire agencies get to choose between a pricey Huey or a cheaper Bo 105. And then, one day, the only option on offer is a Eurocopter Squirrel.

And the 'market' is complicated. BC is home to Port Alberni-based Coulson Group with their range of fixed-wing FireLiners and mid-sized Helitankers. But, every Summer, we choke on wildfire smoke because the Gov't of BC's search for economies has made US western states a much smarter move for airtanker operators. Any commercial operator would be foolish to choose otherwise ... so lemme know when you see those billionaires coming to save the day.

 

[Foo Fighter]

The problem we have seen with contractors is servicing going to pot, as we have seen, it cost's airframes and lives.

 

[Apophenia]

The problem we have seen with contractors is servicing going to pot, as we have seen, it cost's airframes and lives.

All a part of owt for nowt. So I guess we're still waiting on those billionaires to deliver ...

 

[riggerrob]

The problem we have seen with contractors is servicing going to pot, as we have seen, it cost's airframes and lives.

Great play on words.
If contractors see more profit in growing marijuana than defending houses ... they might shift their energies towards protecting marijuana plantations.
Do they still have outdoor marijuana plantations in California?
Even before marijuana was legalized in Canada, most grow ops had moved indoors where they got precise amounts of UV light and hydroponic nutrients.

It might become a good idea to buy a house beside a grow op .......

 

[jfvd06940]

This was inspired by an aeronautical engineering student posting on this forum. His semester project is to design a fire-fighting airplane.

What if we start a group design of a new fire-fighting airplane.
It cannot be based upon an old military-surplus airframe, but can use military-surplus engines, avionics, etc.

We start by defining the mission.
How far from home base?
What type of terrain around the fire?
What types of trees and fuel?
How quickly do we need to extinguish?
Do we need to knock down the fire with a single drop?
How many tons of water or retardant to knock down a typical fire?
Do we need to be able to refill from a nearby lake or swimming pool?
How many minutes to turn-around at home base?
How long must it loiter?
How many drops before needing to refuel?
Does the airplane need to be able to land on water?
What sorts of avionics: radar, sonar, infrared, synthetic vision, etc.?
Does it need to be manned?
How far away can ground crew be stationed?
Will we need another airplane orbiting over the fire to provide a data link?
How many crew?

I am leaning towards a new airframe built around components (engine, sensors, auto-pilot, etc.) from a military-surplus RQ-?? military drone. The airframe will need to be stronger and lower aspect ratio for maneuverability in steep mountain valleys.

What are your thoughts?

More of a fun one than a serious one. An F-111 paired with a precise liquid nitrogen release system paired with sensor sensor systems in sensitive areas would do well, not many F-111s were made but the somewhat recent retirement and lack of high tech equipment means many could be brought from scrapyards and put into service. It's swing wings make it good at low level manoeuvres as well as allowing it to reach supersonic and reach those far away areas more quickly. A liquid nitrogen bomb wouldnt be too hard to make just have a fuse based heat increase and then with enough liquid nitrogen you could paint the nearest 100 yards with it. The Aardvark's stellar payload capacity is also a big help

 

[Apophenia]

More of a fun one than a serious one... F-111s ... somewhat recent retirement ... means many could be brought from scrapyards ...

Not really. It costs a lot to store airframes for 15-to-30 years (the "recent retirement" dates for F-111s). Disposals for out of service types will come sooner than imagined.

So, alas, there are not scores of Aardvarks in storage. At present, the AMARC boneyard at Davis-Monthan counts exactly 1 x F-111F remaining in storage. In Australia, other than the 13 detailed for museums/display, ex-RAAF F-111s were chopped up and buried.