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

Hypersonics Anonymous said:
Just throwing ideas out there, for the budget of your local fire department none of said thrown ideas could be developed...
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Just about everything is handled by the State and Federal governments or contractors employed by them. There is not enough money for most municipalities or counties to buy and operate aerial firefighting aircraft.

Grey Havoc said:
Arguably though, the use of primarily secondhand aircraft for firefighting has long since reached the point of diminishing returns in those cases where it wasn't a cost fallacy from the outset.
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It's very hard for most agencies to beat free or cheap from old DOD stock via the GSA and intra-service transfers. Same way the Coast Guard ended up with the USAF C-27's (coincidentally initially requested by the Forest Service for use as air-tankers before the GAO awarded them to the Coast Guard who took them and then sent some Herks to USFS instead).

And just like militaries worldwide have learned, it is easier to get pols and bean counters to agree to pay to keep the fleet you already have your hands on flying than it is to fund a brand new fleet acquisition and all the associated costs for logistics, training, transition, etc-- even if ostensibly the new aircraft would cost less over a period of X-amount of years and pay for itself.

And for civilian contractors, who comprise a large percentage of on-call aircraft available, there would need to be a total change to the way contracts are awarded by state and federal agencies to generate capital or a guaranteed pay schedule that would enable them to get credit needed for a new fleet. Or expand the USFS acquisition process and lease the aircraft to contractors who will operate them.

One of the ideas that makes sense to me is pushing H-model Herks out of active and reserve squadrons in favour of new build J-models. Then give those new(-er) H-models to National Guard units, that states can use for any purpose it sees fit to fund (including aerial firefighting with MAFFS, as the Reserve currently does in CA). Eventually, as numbers come to active duty squadrons, it allows pushing older J-models to Guard units and eliminating the H's from the DOD units, where the GAO can parse them out to whoever it sees fit (including USFS).

All the plans that would work need congress to allocate real money instead of punting continually. So we're doomed. ;)
 
What IS urgently needed is a system of alarms that informs the teams as soon as there is a fire. The sooner the alarm gets out the sooner it can be extinguished. Possibly with that one golden drop. With enough secondary team sites, millions could be saved. I know, the investment is unlikely. Reactive rather than proactive.
 
Dear Del,
Is there any way for state legislators to blur the distinction between state-funded National Guard and state-funded fire-fighters?
If they could combine maintenance and training resources, how much would that reduce overall costs?
 
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Well, that's why I like the NG route. The aircraft and equipment are acquired federally through the DOD.

I'm not a lawyer, but it seems like it'd be easy to allocate funds via state legislatures to either the NG directly, or from a fire/forestry allocation that pays out to cover the NG cost as needed instead of paying to a contractor for those flights.

Under "State Active Duty" status (for emergencies like applicable here) the Guard is normally funded by the state. A federal order from the President (under Title 32) can be issued for that as well, which would mean federal funding, but still controlled locally. I don't know how common or concurrent that is with a federal emergency declaration; it's not something I've ever looked at, though obviously it releases other federal monies.
 
Interesting, thanks for that. No idea how big the fire needs to be before it gets seen though.
 
I've thought about this every time a big fire gets out of hand out west. This is an airship based system, helium or perhaps hot air. Here I have dual airships supporting a large tank. The whole system can be tied to a water source or cem. tank with some sort of pump system and supported hoses up to the airship. This could be a tethered system or independent. I know your talking about huge weights and stability issues- especially close to a fire but it appears this could be done with existing tech.
 

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autoeac said:
I've thought about this every time a big fire gets out of hand out west. This is an airship based system, helium or perhaps hot air. Here I have dual airships supporting a large tank. The whole system can be tied to a water source orcem. tank with some sort of pump system and supported hoses up to the airship. This could be a tethered system or independent. I know your talking about huge weights and stability issues- especially close to a fire but it appears this could be done with existing tech.
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Certain to be popular with governments at any rate.
 
@autoeac : nice illustration.

But remember that air is ~1000 time less dense than water. So for every kg of water lifted, you'll need to displace 1000kg of air. Hence for every cube of 10cm of water, 1 cubic meter of air.

If you want to haul 10,000kg of water, your airship would have to have a volume of 1,000,000cubic meter of air or 200,000cubic meter of H2 (H2 is roughly 15 time less dense than air - Hindenburg size).

That's not something that would be able to maneuver in a pocket of air like it should in canyons for example... Not talking about the perspectives of doing some low level flying overhead a raging fire in an airship full of... H2! ;)
 
TomcatViP said:
@autoeac : nice illustration.

But remember that air is ~1000 time less dense than water. So for every kg of water lifted, you'll need to displace 1000kg of air. Hence for every cube of 10cm of water, 1 cubic meter of air.

If you want to haul 10,000kg of water, your airship would have to have a volume of 1,000,000cubic meter of air or 200,000cubic meter of H2 (H2 is roughly 15 time less dense than air - Hindenburg size).

That's not something that would be able to maneuver in a pocket of air like it should in canyons for example... Not talking about the perspectives of doing some low level flying overhead a raging fire in an airship full of... H2! ;)
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Obviously the math part is not my strong point. I appreciate a good strong level head...even if it is a buzz kill. The weight of the hoses I thought would be excessive too. Dual Hindenburgs—Now that would be a sight!
 
I reckon you have a strong point for us, fana, with that Zwilling Hindenburg.
Now, who's got the number of those guys that mated two yacks together with a jet engine? :)
 
You might even consider airships.

Remember, some of them had cloud cars dangling.

What if those were hoses with a drone attached to a nozzle? Gravity fed, thrust vectored nozzles. The airship provides shade—-the nozzles—-precision.

You don’t have to bomb everything…fast hose it down. Other tankers deploy massive amounts not even on the fire itself, put perhaps around it. Remember, these things generate their own weather, air currents. Perhaps disrupt that?

There may be a smarter way of doing this besides the direct approach. Over the hottest parts…drop bladder bombs. Reverse napalm.

Small drone cap for small fires.
 
Hey there @riggerrob . Not sure if you are referring to my post in one of the top threads in this section of the site with respect to designing a firefighting aircraft. Definitely an interesting challenge to design a firefighting aircraft. Hopefully the RFP we are following could help guide folks on the fixed wing side located at the following link under the "2022 Design Competition RFPs" (undergraduate - Responsive Aerial Firefighting Aircraft): https://www.aiaa.org/get-involved/students-educators/Design-Competitions

Apparently this RFP was drafted by someone with ties to Lockheed Martin and there was apparently a design concept developed that helped guide the RFP. Not sure of the veracity of the latter, but that's what I've heard.
 
Dear Raptor 101,
Sorry, but I was not referring specifically to your earlier post.
I was just trying to focus wannabe designers on an airplane suitable for a specific mission.

Thanks for the reference. The 2015-2016 Graduate Team competition also included a fire-fighting airplane. The winner sort of looked like a PZL Belphagor missing its lower wing, but adding a second engine.
 
All good. Yeah that year my college won both first and third. That top design has influenced some teams this year, but most are heavily influenced by the C-130 as there are C-130 tankers with similar performance criteria like Coulson's planes.

In regards to other designs seen this year, there has been at least two designs with canards and aft wings with one design with tip tails. Outside of that I have only seen one or two conventional twin jet designs going for the optimal 8,000gal load.

Some of the ideas in this thread are pretty interesting and some information about the financial side are great to know.
 

A very informative long-form article about wildfires and also about - even prehistoric (!) - traditions of controlled low-intensity burns that modify biotopes in ways beneficial to diversity. Many landscapes which we might hold as emblematic of "wilderness" may in fact be the results of millennia long anthropocenic projects. Anyway, information such as this can only clarify what potential uses cases remain for firefighting aircraft - protecting inhabited regions, farmland and preventing "megafires" which threaten actual devastation and destroy large carbon sinks, perhaps.
 
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Conceptual design of a firefighting biplane. Addresses the design in the conceptual phase.

www.researchgate.net

(PDF) Aerodynamic, dynamic and conceptual design of a fire-fighting aircraft

PDF | This paper presents an evaluation of available aircraft types and demonstrates the lack of a low cost aircraft optimized for fighting forest... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net www.researchgate.net
 
Dynoman said:
Conceptual design of a firefighting biplane. Addresses the design in the conceptual phase.

www.researchgate.net

(PDF) Aerodynamic, dynamic and conceptual design of a fire-fighting aircraft

PDF | This paper presents an evaluation of available aircraft types and demonstrates the lack of a low cost aircraft optimized for fighting forest... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net www.researchgate.net
Click to expand...
That study is based upon the proposed PZL-240 Pelikan biplane crop-duster with a turboprop engine.
Since Air Tractor has proven that there is considerable overlap between crop-dusters and fire-fighters, this concept deserves further analysis.

The PZL-240 configuration looks like an antiquated biplane but is based upon a proven configuration. The chief advantage of biplanes is their lighter structural weight per square foot of wing area. Since crop-dusters don't need to cruise very fast, the extra drag (struts and wires) is insignificant. But slow cruise speed can be a dis-advantage to a fire-fighting plane that may have to dash hundreds of miles to reach a remote wildfire.
May I suggest supplemental ferry fuel tanks in the upper wing? This reduces the risk of accidentally mixing fuel and retardant in the same (fuselage) tank.

PZL sketched 3 different upper wing root configurations.
The first includes conventional, thin cabane struts.
The second has a long-chord center strut flanked by more conventional thin V struts. Does the central strut include a loading chute?
The third has gulled wing roots to ease access to refill the central tank/hopper One American crop-duster prototype tried this configuration, but it never entered production.
Finally, may I suggest a fourth wing root configuration with a deep fuselage incorporating the cockpit above the hopper (aka. Australian Transavia PL-12 Agtruk). The raised cockpit will improve visibility. It also helps if the pilot's eyes are forward of the wings' leading edges. A deep fuselage that places the hopper hatch level with the top of the top wing. A deep main water tank will reduce "sloshing" ala. PZL Pelphagor. This would also make it easy to raise the upper mold line of the rear fuselage, improving yaw stability and eliminating the need for the supplemental tail fins on some of PZL's sketches.
The fuselage could also benefit from simplified external mold lines. This would simplify production ... like Grumman's Agcat.
While the aft-mounted cockpit is great for crash survivability, it does limit visibility.

A later PZL-240 sketch includes tri-cycle landing gear, which will simplify conversion training for younger pilots.
The PZL-240 has odd-looking swept tail surfaces. Were they left over from another project? Straight tail surfaces might marginally simplify production.
 
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UpForce said:
A random Twitter encounter with a Chinese UAV manufacturer having apparently successfully tested two satellite guided fire-extinguishing projectiles. Effective area according to the tweet 450m².

https://twitter.com/x/status/1468581132375453697
View: https://twitter.com/HenriKenhmann/status/1468581132375453697
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This reminds us of a USAF/Us Forest Service Experiment in the immediate aftermath of WW2. They hung drop tanks - full of water - under P-47 Thunderbolts (?) and dropped them on forest fires. Results were underwhelming and the project was soon dropped (pun intended).

Similar experiments in Ontario (1930s or 1940s) saw them dropping paper bags - filled with water - on small forest fires. The Ontario Provincial Air Service flew slow floatplanes like Norsemen and DHC-2 Beavers. Again results were underwhelming and the project was soon dropped.

Now the Chinese communist gov't has reinvented the project with high-tech, high-cost, electronically-guided, water bombs. Holy hunting mosquitos with a sophisticated, electronically-guided, self-steering cruise-missile!
 
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overscan (PaulMM) said:
From Zhuhai 2021. I think its safe to say this is the high end solution.View attachment 665261
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Definitely a high-cost solution.
I suspect that the large internal tanks were originally designed to fly liquid fuel to some of Communist China's "islands" in the South China Sea. Any agricultural or fire-fighting capability is secondary.

I suspect that China will only use those huge flying boats to fight fires that threaten major cities or major highways. e.g. water-drops that provide phot-ops for senior Communist Party officials. Peasants and lumberjacks be damned.
 
riggerrob said:
Dynoman said:
Conceptual design of a firefighting biplane. Addresses the design in the conceptual phase.

www.researchgate.net

(PDF) Aerodynamic, dynamic and conceptual design of a fire-fighting aircraft

PDF | This paper presents an evaluation of available aircraft types and demonstrates the lack of a low cost aircraft optimized for fighting forest... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net www.researchgate.net
Click to expand...
That study is based upon the proposed PZL-240 Pelikan biplane crop-duster with a turboprop engine.
Since Air Tractor has proven that there is considerable overlap between crop-dusters and fire-fighters, this concept deserves further analysis.

The PZL-240 configuration looks like an antiquated biplane but is based upon a proven configuration. The chief advantage of biplanes is their lighter structural weight per square foot of wing area. Since crop-dusters don't need to cruise very fast, the extra drag (struts and wires) is insignificant. But slow cruise speed can be a dis-advantage to a fire-fighting plane that may have to dash hundreds of miles to reach a remote wildfire.
May I suggest supplemental ferry fuel tanks in the upper wing? This reduces the risk of accidentally mixing fuel and retardant in the same (fuselage) tank.

PZL sketched 3 different upper wing root configurations.
The first includes conventional, thin cabane struts.
The second has a long-chord center strut flanked by more conventional thin V struts. Does the central strut include a loading chute?
The third has gulled wing roots to ease access to refill the central tank/hopper One American crop-duster prototype tried this configuration, but it never entered production.
Finally, may I suggest a fourth wing root configuration with a deep fuselage incorporating the cockpit above the hopper (aka. Australian Transavia PL-12 Agtruk). The raised cockpit will improve visibility. It also helps if the pilot's eyes are forward of the wings' leading edges. A deep fuselage that places the hopper hatch level with the top of the top wing. A deep main water tank will reduce "sloshing" ala. PZL Pelphagor. This would also make it easy to raise the upper mold line of the rear fuselage, improving yaw stability and eliminating the need for the supplemental tail fins on some of PZL's sketches.
The fuselage could also benefit from simplified external mold lines. This would simplify production ... like Grumman's Agcat.
While the aft-mounted cockpit is great for crash survivability, it does limit visibility.

A later PZL-240 sketch includes tri-cycle landing gear, which will simplify conversion training for younger pilots.
The PZL-240 has odd-looking swept tail surfaces. Were they left over from another project? Straight tail surfaces might marginally simplify production.
Click to expand...
 
An interesting design for a bucket bomber helicopter adaptation (here the S-92):
The CFRP collapsible tank weights only 300+ kg and can hold 4000L of water (1000+ gallons) :

Helitak-image-1-900x593-1.jpg


verticalmag.com

Firefighting could be secondary mission for aging S-92s, says Milestone

Milestone’s recently-launched program to convert an offshore Sikorsky S-92 into a firefighting aircraft could be a sign of things to come as the offshore heavy fleet ages, the lessor says.
verticalmag.com verticalmag.com
 
The DHC-515 will be an updated variant of CL-series aircraft, which had been products of Viking Air, also a Longview subsidiary. Viking launched the CL-515 in 2019 but put the effort on ice during the pandemic.

Viking previously said the CL-515 would have twin Pratt & Whitney Canada PW123AF turboprops and Collins Aerospace’s Pro Line Fusion digital avionics. It was also to have improved corrosion protection, an increased landing weight and ability to carry 7,000 litres (1,850USgal) of water, up from the CL-415’s 6,000-litre capacity.

The DHC-515 can be equipped with a “spray boom for insect control or oil-spill dispersant”, or a larger cargo door suited for disaster-relief missions, according to Viking’s website. They can also be equipped as medevac aircraft.
Click to expand...

www.flightglobal.com

De Havilland to develop updated water bomber called DHC-515 Firefighter

De Havilland Aircraft of Canada has re-launched development of an updated water bomber based on the stalwart CL-series line of firefighting aircraft.
www.flightglobal.com www.flightglobal.com
 
riggerrob said:
... I suspect that the large internal tanks were originally designed to fly liquid fuel to some of Communist China's "islands" in the South China Sea. Any agricultural or fire-fighting capability is secondary.

I suspect that China will only use those huge flying boats to fight fires that threaten major cities or major highways. e.g. water-drops that provide phot-ops for senior Communist Party officials. Peasants and lumberjacks be damned.
Click to expand...

Going back a ways, I know ...

You may well be right about "fire-fighting capability [being] secondary". But, when the International Test Pilot School was instructing Chinese test pilots and engineers for the AVIC AG600 Kunlong programme, their final training was doing circuits around the Alberni Valley aboard Coulson Aviation's 'Hawaii Mars'.

The question remains, were the Chinese (or ITPS) interested in C-FLYL because she was a water bomber ... or just because the Mars was the biggest flying boat available?
 
Apophenia said:
riggerrob said:
... I suspect that the large internal tanks were originally designed to fly liquid fuel to some of Communist China's "islands" in the South China Sea. Any agricultural or fire-fighting capability is secondary.

I suspect that China will only use those huge flying boats to fight fires that threaten major cities or major highways. e.g. water-drops that provide phot-ops for senior Communist Party officials. Peasants and lumberjacks be damned.
Click to expand...

Going back a ways, I know ...

You may well be right about "fire-fighting capability [being] secondary". But, when the International Test Pilot School was instructing Chinese test pilots and engineers for the AVIC AG600 Kunlong programme, their final training was doing circuits around the Alberni Valley aboard Coulson Aviation's 'Hawaii Mars'.

The question remains, were the Chinese (or ITPS) interested in C-FLYL because she was a water bomber ... or just because the Mars was the biggest flying boat available?
Click to expand...
Martin Mars was one of the few 4-engined flying boats available.

Shin-Mewa are the only other company still building 4-engined flying-boats.
Given "frosty" politics over the South China Sea Islands, I doubt if Japan would have been willing to rent out a 4-engined Shin-Mewa flying boat to Communist China.
 
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riggerrob said:

... Shin-Mewa are the only other company still building 4-engined flying-boats.
Given "frosty" politics over the South China Sea Islands, I doubt if Japan would have been willing to rent out a 4-engiend Shin-Mewa flying boat to Communist China.
Click to expand...

Indeed. And I'm betting that Beijing would have been too 'frosted over' to even ask the Japanese!
 

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