"Hercs" or "Caribous" -Can They Be Used as FIREFIGHTERS??
Sprucegoose
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"Hercs" or "Caribous" -Can They Be Used as FIREFIGHTERS??
Yes they can, but please keep this accident in mind!
Bushy
Colin Pay was working on a water pickup system for fixed wing aircraft. Surely this would work if the drag from the pickup system was behind the C of G.
Water-skiing then adding 3,000 kg of water strikes me as a bit tricky, especially if you add in the typical "wildfire" wind & heat conditions.
... and if Col couldn't pull it off, nor could you or I.
Maybe a retractable stinger in the tail to pick up water. And with a weak link so that it breaks off if the drag force is too great.
Will we let this research die with Colin?
Last edited by Horatio Leafblower; 14th Jan 2009 at 22:19.
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For this reason I would feel more comfortable with an Aircrane that can quickly suck up a few thousand litres from the dam and do multiple dumps rather than rely on one or two fixed wing a/c.
In my area we don't have many fires that can only be attacked from the air, but it is not uncommon to have parts of a planned control line you can't send a Tanker coz it is too rough, or the fire is too hot or there is just not adequate 'bug-outs' if it all starts to look a bit 'Linton'.
And what better to shrink turn around time than use aircraft with land in water to pickup water.
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The RAAF already spends a fortune on the fatigue management of the C130s. Using them in those sorts of ops would chew up airframe hours like nothing else.
And the Caribous hgave been more or less ready for retirement for years now.
Nice idea though.
As for water skiing... I'm with Horatio on that. Even if Col had not crashed, I think someone (either casa in certificating it, or the RFS in issuing the contracts) would have said it was not a wise idea sooner or later, and effectively stopped the development. Read the ATSB interim report.
It doesn't matter where the water pickup is positioned longitudinally on the aircraft (either at the wheels or at the tail) - as long as you have a drag force below the cg, it will always cause a pitch down moment.
As for shearing linkages - it would be very difficult to tailor these to a specific load, and not have them break during normal operations (think of hte vibrations involved).
Interesting idea... on paper.
And the Caribous hgave been more or less ready for retirement for years now.
Nice idea though.
As for water skiing... I'm with Horatio on that. Even if Col had not crashed, I think someone (either casa in certificating it, or the RFS in issuing the contracts) would have said it was not a wise idea sooner or later, and effectively stopped the development. Read the ATSB interim report.
It doesn't matter where the water pickup is positioned longitudinally on the aircraft (either at the wheels or at the tail) - as long as you have a drag force below the cg, it will always cause a pitch down moment.
As for shearing linkages - it would be very difficult to tailor these to a specific load, and not have them break during normal operations (think of hte vibrations involved).
Interesting idea... on paper.
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Spodman,
The chances of getting a viable load off Lake Eildon are diminishing by the day, with the likelihood increasing that the intakes will be clogged by algae or frog spawn....
The chances of getting a viable load off Lake Eildon are diminishing by the day, with the likelihood increasing that the intakes will be clogged by algae or frog spawn....
Originally Posted by dash27
And so for the last decade, fires have been p#ssed on by smaller helicopters. It hasn't been until recent times that they have started to get serious with the Ericson Skycranes and the Bell 212's, 412's. It takes numbers of suitable aircraft in proximity to facilities to refuel and resupply.
JetRangers/Squirrels haven't been used for waterbombing for more than 12 years! I did the first BK117 waterbombing in 1997 in NSW, and NRE (now DSE) were then using 212's. The first Aircrane was also put on contract in Victoria that year
Crane drops tend to average 6-7000lt, 412's about 1600lt. Turn rounds depend on proximity of water sources, which have to be big enough (in Victoria) for bellytank equipped machines, but anywhere between 4 to 15 minutes would be the norm.
I haven't flown fires for 2 years, but 1,800,000lts was my drop total for 2006/07 season in my BK117
John,
I can't say whether or not they get much use, but there are FIVE Squirrels and TWO Jetrangers on the Victorian contract for this year (I'm reading from the list and can quote regos if needed), which is very similar to past years. There are also a few Longrangers and a lone BK117, which all together make up the type 3 (or Light helo) fleet.
In the medium (Type 2) there are FOUR 212s and a single 205.
Then you get to the Heavies (Type 1) - TWO Aircranes and TWO S61s.
Plus there are the usual heap of SEATs - TWELVE in fact.
I can't say whether or not they get much use, but there are FIVE Squirrels and TWO Jetrangers on the Victorian contract for this year (I'm reading from the list and can quote regos if needed), which is very similar to past years. There are also a few Longrangers and a lone BK117, which all together make up the type 3 (or Light helo) fleet.
In the medium (Type 2) there are FOUR 212s and a single 205.
Then you get to the Heavies (Type 1) - TWO Aircranes and TWO S61s.
Plus there are the usual heap of SEATs - TWELVE in fact.
methinks what we got now wont change much 
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Bushy / Horotio Leafblower,
There is a system for collecting water in 802 Air Tractors available commercially - Wipaire / FirebossLLC make a set of floats designed for this job.
There are two issues with them.
Cost - probably around $500k US for a pair of floats
Weight - probably adds around 1200 lbs to the empty weight of the aircraft. Fireboss publish the ability to pick up between 2500 and 3000 liters of water depending on the fuel load.
Scooping water for firebombing is not a new idea - it was a option on the factory De Havilland Beaver floats in the 1950's - our flight manuals include a supplement regarding the use of it.
IF the resistance of the skis and pickup points can be located behind the C of G it will significantly reduce the risk of a water loop. Basing the design on the shape and positioning of the bottom of aircraft floats forward of the step would be a good place to start. Apart from the structural needs the rest of the float is just there to displace water at taxi speeds - its not necessary if you don't slow down.
There is a system for collecting water in 802 Air Tractors available commercially - Wipaire / FirebossLLC make a set of floats designed for this job.
There are two issues with them.
Cost - probably around $500k US for a pair of floats
Weight - probably adds around 1200 lbs to the empty weight of the aircraft. Fireboss publish the ability to pick up between 2500 and 3000 liters of water depending on the fuel load.
Scooping water for firebombing is not a new idea - it was a option on the factory De Havilland Beaver floats in the 1950's - our flight manuals include a supplement regarding the use of it.
IF the resistance of the skis and pickup points can be located behind the C of G it will significantly reduce the risk of a water loop. Basing the design on the shape and positioning of the bottom of aircraft floats forward of the step would be a good place to start. Apart from the structural needs the rest of the float is just there to displace water at taxi speeds - its not necessary if you don't slow down.
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Werbil -
Yes, I am aware that water scooping has been done for many years using float equipped aircraft/flying boats. I'm aware of the Fireboss 802.
However the way I see it is this:
If the aircraft is planing on the surface, scooping water, and is subject to a subtle disturbance, then the difference between using a water hull and skis is that the hull's increasing displacement as it lowers in the water results in greater buoyancy, forcing the aircraft to pitch up. It is therefore a stabilising force.
Whereas if the skis are lowered further into the water, there is a significant an increase in drag (below the cg), there is no significant increase in buoyancy, and although there is some hydrodynamic lift produced by the skis, I would view it as primarily a destabilising situation (i.e. nose over into the water).
In regards to the drag load being behind the c.g. preventing a water loop, this is true for lateral stability yes, but does not affect the longitudinal stability issue (i.e. nose over into the water).
That's why they have been putting scoops on floatplanes and flying boats since the 1950's, but by 2008, only Col Pay had been trying it with skis (unless someone knows of some other examples). Any water-based ski-equipped/hydro-foil equipped aircraft? I can't think of any. I suspect for the same reason - too unstable!
Yes, I am aware that water scooping has been done for many years using float equipped aircraft/flying boats. I'm aware of the Fireboss 802.
However the way I see it is this:
If the aircraft is planing on the surface, scooping water, and is subject to a subtle disturbance, then the difference between using a water hull and skis is that the hull's increasing displacement as it lowers in the water results in greater buoyancy, forcing the aircraft to pitch up. It is therefore a stabilising force.
Whereas if the skis are lowered further into the water, there is a significant an increase in drag (below the cg), there is no significant increase in buoyancy, and although there is some hydrodynamic lift produced by the skis, I would view it as primarily a destabilising situation (i.e. nose over into the water).
In regards to the drag load being behind the c.g. preventing a water loop, this is true for lateral stability yes, but does not affect the longitudinal stability issue (i.e. nose over into the water).
That's why they have been putting scoops on floatplanes and flying boats since the 1950's, but by 2008, only Col Pay had been trying it with skis (unless someone knows of some other examples). Any water-based ski-equipped/hydro-foil equipped aircraft? I can't think of any. I suspect for the same reason - too unstable!
Originally Posted by AllanL
ohn,
I can't say whether or not they get much use, but there are FIVE Squirrels and TWO Jetrangers on the Victorian contract for this year (I'm reading from the list and can quote regos if needed), which is very similar to past years. There are also a few Longrangers and a lone BK117, which all together make up the type 3 (or Light helo) fleet.
I can't say whether or not they get much use, but there are FIVE Squirrels and TWO Jetrangers on the Victorian contract for this year (I'm reading from the list and can quote regos if needed), which is very similar to past years. There are also a few Longrangers and a lone BK117, which all together make up the type 3 (or Light helo) fleet.
The light helicopters are all Firebirds, not Helitacks: this is reflected in their callsigns. They are only used for firespotting/aerial incendiary/AAS roles, not for firebombing
One Longranger and one Squirrel are each permanently assigned to the two Cranes for AAS for each heavy Helitack. The BK117 is a contract Helitack, not really a Type 3 (a constant issue, but hardly relevant ).
Thanks John.
Although I also see that the contract list details their "Firebombing System" as being various capacities of buckets (410 to 680 litres) with the 117 having a 1200 litre belly tank.
Although I also see that the contract list details their "Firebombing System" as being various capacities of buckets (410 to 680 litres) with the 117 having a 1200 litre belly tank.
AllanL,
The Firebirds are required to carry all sorts of stuff, including HF Radio, wool blankets and Bambi buckets. Trust me, they don't use any of them! (Except in an emergency.)
The day that BK belly tank actually fights a fire with a full 1200lt, the sun will rise in the west......
More like 900lt average drop Another anomaly, the SAU will credit each drop at max tank capacity, regardless of what's actually dropped, unless the operator reports otherwise. Great for statistics, but not entirely accurate; indeed, quite misleading when applied over a campaign fire 
The Firebirds are required to carry all sorts of stuff, including HF Radio, wool blankets and Bambi buckets. Trust me, they don't use any of them! (Except in an emergency.)
The day that BK belly tank actually fights a fire with a full 1200lt, the sun will rise in the west......
More like 900lt average drop Another anomaly, the SAU will credit each drop at max tank capacity, regardless of what's actually dropped, unless the operator reports otherwise. Great for statistics, but not entirely accurate; indeed, quite misleading when applied over a campaign fire
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Nick2007
At planing speeds (which would be used for water scooping) buoyancy doesn't enter into the equation - for all practical purposes the only forces provided by the water are hydrodynamic forces. Yes, a subtle disturbance will push the floats further into the water - but at the speeds we are talking about there is only a very, very small area of the floats in contact with the water (all in front of the step) - the sides and bottom of the floats behind the step of the floats only get wet by spray.
If you land nose low in a float plane they are very directionally unstable - have a look at this video - YouTube - Floatplane accident - if you let it start you are along for the ride. Full back stick is the only thing that may save you.
Floatplanes also have a nose down tendency due to the drag - it is especially pronounced if you leave the wheels down on landing as this video demonstrates - YouTube - Sea Plane Crash
With the DHC-2 installation (they were straight floats) increased loads were permitted when water scooping only if the aircraft was kept at step speed or above (I don't think the floats had enough reserve buoyancy meet certification requirements).
The location of the step on floatplanes is critical - to far aft and it is impossible to get airborne - to far forward and directional stability on the water at high speed is the problem.
W
At planing speeds (which would be used for water scooping) buoyancy doesn't enter into the equation - for all practical purposes the only forces provided by the water are hydrodynamic forces. Yes, a subtle disturbance will push the floats further into the water - but at the speeds we are talking about there is only a very, very small area of the floats in contact with the water (all in front of the step) - the sides and bottom of the floats behind the step of the floats only get wet by spray.
If you land nose low in a float plane they are very directionally unstable - have a look at this video - YouTube - Floatplane accident - if you let it start you are along for the ride. Full back stick is the only thing that may save you.
Floatplanes also have a nose down tendency due to the drag - it is especially pronounced if you leave the wheels down on landing as this video demonstrates - YouTube - Sea Plane Crash
With the DHC-2 installation (they were straight floats) increased loads were permitted when water scooping only if the aircraft was kept at step speed or above (I don't think the floats had enough reserve buoyancy meet certification requirements).
The location of the step on floatplanes is critical - to far aft and it is impossible to get airborne - to far forward and directional stability on the water at high speed is the problem.
W
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Firebombers
As one of the pilots involved with fighting the Pt. Lincoln fire, I can assure our fellow respondents that the two AT602 and two AT802 SEAT'S provided excellent support over the life of the fire. With two AT602's based at lincoln for the summer and two AT802's arriving within 1.2 hrs from up to 145nm away within 1 hour of activation demonstrates the versatility of the fixed wing fleet within Sth Aust. The crane took in excess of 2 hrs to get to lincoln, did one load, refuelled, did 3 loads, pulled out with a maintenance problem, further 3 loads, repeat previous, then for the media continued for a further hour when the fire was benign and the SEAT's had been stood down! No sour grapes here but I pay my taxes too! The Ericsson is a magnificent platform for fire operations but is massively expensive, maintenence intensive, and requires ready access to available water resources to be effective. This was not available at the recent conflagration at Pt Lincoln. If the wind did not preclude the crane from scooping from the bay, the fire would not have had the intensity anyway, so the SEAT's would still have been effective. I am very proud of the work that all who were involved in this incident achieved in very arduous and trying flying and ground support conditions (including the crane guys) but to achieve what we did took an exceptional aircraft, and for my money that is the SEAT Airtractor's Cheers.......
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Well done
Well done ozaggie. While the others are talking about it you are out there doing it.
One day our authorities may realise that bush fires happen more than once and they should organise the fire breaks, water supplies, and machines that will be needed to fight or prevent them. There are a lot of good people working on that now, with scant resources.
We haven't yet built a sucessful safety capsule for crews that get trapped in fires. We have tried and quit.
One day our authorities may realise that bush fires happen more than once and they should organise the fire breaks, water supplies, and machines that will be needed to fight or prevent them. There are a lot of good people working on that now, with scant resources.
We haven't yet built a sucessful safety capsule for crews that get trapped in fires. We have tried and quit.
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Werbil,
Ok so the way I see it now is -
The skis were - from a hydrodynamics point of view - acting like a set of floats with a step set very far forward, so the whole setup was laterally unstable (or on the point of instability) when planing on the water.
Ok so the way I see it now is -
The skis were - from a hydrodynamics point of view - acting like a set of floats with a step set very far forward, so the whole setup was laterally unstable (or on the point of instability) when planing on the water.
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