NSW Boeing 737 Fire Bomber

NSW Rural Fire Service today took delivery of the first full time fire bomber flying tanker. The aircraft has been named Marie Bashir after the former NSW Governor. 

The aircraft carries the same colours as the photo below, but with NSW RURAL FIRE SERVICE above the windows. Coulson name removed.

I saw this today, but asked myself.... After it dumps, how long does it take to refill??

I struggle to see where this aircraft is going to be totally and outstandingly effective.

The 737 obviously needs to land to refill - where are the multitude of airstrips long enough to take a 737?

What about the turnaround time? I was under the impression the 737 is no F/A-18, it must take considerable time to do the turn around, particularly if the only available strip is many NM away.

What about the refilling methods? Are they trucking the water in to the nearest long airstrip? It would take considerable time to organise the necessary bulk water supplies - and I can't see where there's many public piped water supplies, that have substantial volumes of water to spare - particularly when it's potable water in their pipes.

What about the refilling process? It can obviously dump 15,000 litres pretty fast - but 15,000 litres is a lot of water to pump back into the tank, in a hurry.

I'm having trouble finding this type of information, as regards the Coulson 737's in action. Plenty of action shots, none of the nitty-gritty logistics info.

I must admit, I was quite surprised to read that the pilots of the Coulson Fireliner reckon their 737 handles and responds beautifully at just 130kts.

I imagine the plane scoops up water from a lake surface like they all do.   The 130 knots seems a bit optimistic unless there's some sort of MAGIC involved.   Nev

Nev, this interview of one of the 737 Fireliner pilots contains his quote that the 737 Fireliner "flies slow really well".

I find it hard to understand how a delta-wing commercial jet, designed to cruise at 450kts at FL380, can perform satisfactorily at slow speeds at very low levels. 

They are talking 150 feet at 130 kts with the 737. To me, that looks like a suicide mission, particularly when you take into account the savage, tornado-like windstorms, generated by large bushfires.

https://www.smh.com.au/environment/conservation/buying-time-the-pilot-behind-world-s-first-boeing-737-water-bomber-20190127-p50tx2.html

I can find absolutely nothing on any of the relevant websites, as to how the 737 Fireliner is refilled.

Plenty of info on how it dumps its load in a fabulous manner - but it obviously refills by magic.

https://fireaviation.com/tag/737/

One of the problems with firebombing is the quality of the water being used. You can't use seawater, it creates corrosion problems in aircraft, and damages the landscape and vegetation with an overload of salt. So you need fresh water - and lots of it, available quickly.

Canada is a whole lot different scenario to Australia. The Canada land mass is 9% freshwater lakes. The country is loaded with 20% of the worlds water.

But in Australia, you can travel a long way, before you find a decent freshwater supply, that has adequate volumes to support firebombing.

I'll bet you $ 50 dollars this 737 (or any) does not scoop water - its a full stop landing for refill

The Airtractor  AT802 carries 3000l and can land anywhere, about 140knot cruise speed. 

Two of these would beat the 737 in most situations for a fraction of the cost.

The NSW rural fire service is a mini empire gone mad in my opinion. We do all pay for this.   

I can't see a high crit M type wing as being optimum for for high lift SLOW low altitude work. If they are landing on wheels they will be doing a lot of work on the brakes or wasting a lot of time and cockpit vis is not ideal either. You are really going to tax the flap system  with that type of OPS. Nev

interesting to know how a big 737 (15000 litres water) competes with a AT802 (3000 litres water) - nice to know - the 737 certainly has more bling !

looks like a 737 is about $ 100 million and a AT 802 about $ 4 million 

Personally I’ve always thought the ideal water bomber is a Canadair amphibian. It can fill up on the run over a lake or I imagine on airports with much less runway than a 737 requires. Always seemed to me that it would be cheaper for insurance companies to unite in ownership and operation of a couple of those rather than pay out for bushfire damage, but then, being insurance companies they can find a reason to renege on payment. (Cynical? You bet!)

Personally I’ve always thought the ideal water bomber is a Canadair amphibian. It can fill up on the run over a lake or I imagine on airports with much less runway than a 737 requires. Always seemed to me that it would be cheaper for insurance companies to unite in ownership and operation of a couple of those rather than pay out for bushfire damage, but then, being insurance companies they can find a reason to renege on payment. (Cynical? You bet!)

 

The AT802 fire boss is a very capable water scooper, I don't  think we have enough dams (with water in them) to make them really practical in oz. 

I read somewhere that these biggies drop fires retardant ahead of the fire, to stop it at that point. The fire retardant is red or orange in colour. It isn’t straight water, it is loaded at an airfield a long way from the fire.

The Coulson 737 Fireliners are ex-SouthWest Airlines aircraft, and on average, they are 23 yrs old - so not exactly the "big bikkies" you might think.

One site says the basic cost of a 737 Fireliner is US$7M.

The NSW Govt is spending AU$26M in total, buying the 737 Fireliner, (along with a 10 yr flight & maintenance personnel contract by Coulson), plus the two Citation V's.

https://www.airmedandrescue.com/latest/news/coulson-and-nsw-purchase-boeing-737-fireliner

Old stuff is cheap but they don't exactly have great strength margins for pulling "G" in turbulence and sweepback and the airfoil section are not Right for the environment/envelope they fly in. Flying personnel in to some place isn't likely to be the wonderful idea it might seem as those vaccuum cleaners under the wings, suck in a lot of muck on all but swept sealed strips. Nev

I'll bet you $ 50 dollars this 737 (or any) does not scoop water - its a full stop landing for refill

 

 

"It can also speed to a major blaze and return rapidly for refuelling. Last week, the plane was deployed to help Tasmania cope with its dozens of bushfires, reloading with water at Hobart airport".

To my knowledge it doesn't dump water - it's some sort of powder.

Nomadpete would probably know more, I think he saw it in action close to his house in the last lot of fires down here.

and I can't see where there's many public piped water supplies, that have substantial volumes of water to spare - particularly when it's potable water in their pipes.

 

Well,

Sydney as well as other cities, is short of water, Dubbo is a lot shorter with dams less than half full.

A couple of plane loads of drinking water, for fire fighting will see us in dire straights.

spacesailor

Marty, the fire bombers drop a fire retardant, which is water combined with a solution or powder, called Phos-Chek.

Phos-Chek is a product containing 85% Ammonium Polyphosphate solution, with 5% Attapulgite clay, and 8% "performance additives", which are a trade secret.

The 8% secret ingredients contain, a gum thickener, a flow conditioner, a colouring agent, and/or corrosion inhibitors.

Iron oxide compounds are the colouring agent, the iron oxide compounds are what give the Phos-Chek its distinctive red colour.

This is done to enable firefighters to see what areas have been coated with the retardant.

The Attapulgite clay has similar properties to Bentonite clay, which absorbs large volumes of water.

However, Bentonite swells when added to water, Attapulgite doesn't.

Attapulgite not only absorbs water, it forms a gel with water, which gel is very sticky.

Essentially, the water containing Phos-Chek lands on the ground and vegetation, but because the water is held in suspension, it can't soak into the ground.

The sticky solution clings to the vegetation and helps smother the fire by denying it access to the fuel.

The heat of the fire releases the water from the sticky solution, thus quelling the fire more effectively than any other application method.

In addition, the cellulose structure of the plants and vegetation that Phos-Chek lands on, is changed to a "non-flammable" carbon, which resists burning.

You can buy Phos-Chek and spray it around your high fire-risk property, and it will retain its fire retardant properties for months, provided it is not rained on heavily.

https://phoschek.com/

The Airtractor  AT802 carries 3000l and can land anywhere, about 140knot cruise speed. 

 

Two of these would beat the 737 in most situations for a fraction of the cost.

 

The NSW rural fire service is a mini empire gone mad in my opinion. We do all pay for this.   

 

In many actual firefights Airtractors struggle to lift 2700litres due to the hot thin air, even at low elevations. But... their turnaround times and ability to get in close to the fire should make them a better resource than a repurposed airliner.

Then there’s the turbulence. I’ve seen footage of a converted DC-10 water bomber’s wings folding up during a fire drop. Australian fire weather extremes might exceed the structural limits of a 1960’s high-altitude airliner.

It’s time to question the power of the bushfire industry.

I would suggest they are not strong enough for that environment especially if the airframes are" tired" after hears of service and pressurisation cycles. They might reduce their AUW to help. Does anyone have the figures?.. Nev

Nev, I don't have any Coulson figures - but the basic 737-300 figures are as follows,

MTOW - 63,277 kg

Empty weight - 32,900 kg

Fuel capacity - 20,100L

The two water tanks hold 15,150L of water = 15,150 kg.

Jet A1 weight, rough rule of thumb, 0.8 kg/L = 16,080 kg in full fuel weight.

So, with full fuel, that makes the total aircraft weight, 64,130 kg - above MTOW.

The tanks would possibly add some amount of weight to the empty aircraft - but in the photos I saw, all the seats are stripped out, so I'm guessing Coulson went on a weight-reduction drive.

Regardless, they need to be running with considerably less than full fuel, to keep the weight down.

 I can't see you using full fuel but It will certainly get a high fuel flow at low levels and those planes don't operate at ambients exceeding 42 degrees normally.  Fire days are generally hotter and in a fire zone likely to be extreme in some spots. The 130 knots???? would have to be full flap.    A lot of this doesn't add up. Nev

I agree. The 737 firebomber is certainly going to be well up in weight, even with half fuel.

I see estimated 737 stall figures of 108kts in landing configuration, and 128kts clean configuration.

With substantial weight, and travelling slow, the AoA is going to be high, so adequate speed is becoming critical.

Dropping at 130kts sounds like BS to me, unless that's a figure the pilots are talking, after they've unloaded the fire retardant.

Or maybe these American firebomber pilots come straight from the Arthur "Bud" Holland School of pilot training, where stall warnings are just an annoyance to be ignored, and 90 deg bank angles are SOP.  

There's another angle in all this, too - noise. Sizeable numbers of people complain about aircraft noise at the best of times, and many airports capable of taking a 737 have noise abatement procedures in place.

I wonder how people around a bushfire will feel about a 737 swooping around their houses at extremely low level, with those CFM56 turbofans pumping out 75-80% power?

Maybe the fire authorities think the people living on the ground will appreciate the sound of a couple of big screaming turbofans coming in at low level, and start relating them to being saved?? Could be the case.