We used long lines in Miramichi last year to resupply relay tanks, that is one in the relay, 2 on the drop and so on. That was only so we could clear the trees, otherwise I prefer a short line, particularly with using the twinStar/Astar, where the line needs to be at least 100 feet.
The big problem with the long line is that it's difficult to see whether the bucket electrics go into the water if you can't see it properly, so they get wet and short out.
If anyone's interested, here's a bit from the helicopter Pilot's Handbook:
This is subject to the normal restrictions, such as weather or night, although fixed wing fire bombing operations do take place in darkness. You may be asked either to help fight the fire itself, move men and materials over natural barriers, scan with FLIR or report its dimensions back to the fire boss. Above a certain size, however, you won't be putting anything out , but rather slowing things down so the guys on the ground who do the real work can get on with it. Of course, what actually happens is a system of organised chaos, where it’s hard to tell if anyone really knows what’s going on and you end up fighting a little bit all by yourself. Otherwise, if you're not part of the operation, you should not be within 5 nm and below 3000 feet agl of the fire's limits. Anyone joining in should be in touch with the bird dog, if there is one—this is a light plane or helicopter used to control the water tankers, and you need to be told when they are coming so you can get out of the way.
Water bombers will be used either to drop retardant or water, sometimes with foam (which should not be dropped near anywhere environmentally sensitive). Retardant is phosphate fertiliser and water, with a dye so you can see where it hit.
Skimmers (like the CL415) pick water up from nearby lakes, but others get reloaded from nearby airstrips prepared for the purpose. Retardant is not actually used on the fire, but around it, so it is contained in a smaller area and allowed to burn out. There will often be dozers trying to create a break round the fire for the same purpose if it is small enough.
Bombers do not usually get below 150 feet, as the water pattern will get disrupted, so your safest height is well below that.
Helicopters make use of handy sources of water, like swimming pools or small rivers, typically using the Bambi Fire Bucket. These days, the minimum machine is likely to be the AStar B2, with anything lower in performance, such as the 206, being relegated to observation or putting out hot spots, since the bucket size is only 90 gallons. In most cases, the killing time is between 30-45 minutes from the start of the fire, so, if you're on standby, your response time should be as fast as possible.
In this case, you will typically be teamed up with three firefighters and their associated gear, which will fill every available hole in the cabin and baggage compartments. You will need enough fuel to get them to the spot and be useful while you're there, and get them back again, so, on the way, take note of the nearest airfield or refuelling spot. If the fire gets big enough, they may well bring fuel down in drums, but by that time the bombers could well be there anyway and you will be sent off to another one.
Your task, as an initial attack team, is just to stamp on a fire just starting, but you could well be involved in just slowing it down around people or property. You will get your instructions from the bird dog. Directions are given with reference to the head or tail of the fire, which are the downwind and upwind ends, respectively. Left and right flanks are counted from the tail to the head.
Anyhow, picking up water in single-engined helicopters beyond gliding distance from shore has the usual problems, plus possible disorientation if you go too far in. Fast moving streams don’t help, making you feel as if you were moving the wrong way, so it’s best to find a calm area, as otherwise you will have to move the helicopter to keep up with the water, ending up in a fast taxi unawares – always face the flow of the stream. Approach the water with some forward speed so the bucket tips over and starts to fill as you progress, as it has a tendency to drift forward otherwise. Get into a low hover, which will help push it under, and lift it mostly out. If you're heavy (i.e. with a lot of fuel), keep the power on and pull the bucket forward in one smooth movement, using translational lift to get airborne.
You will find that the wind direction is critical. Be careful if you're longlining with a bucket, as the connector plug for the release is difficult to see and might go under water where it shorts out. Longlining would be used where the trees are very tall and there is no water for the hoses nearby—the team will have a small relay tank for you to fill.
When actually bombing, there is about a second's delay between pressing the button and the liquid reaching its target, and pulling up before doing so will help stop the bucket swinging and making you miss in high winds, aside from punching it into the target. Although there is a risk of fanning the flames, you do need to get low over the fire, and preferably slow, as a good dousing will do most to kill them - evaporation will take its toll on whatever is dropped, ensuring that only so much of it is actually effective, and raising the humidity.
Hovering is not recommended, as your downwash may not only fan the fire (even up to twice tree height), but also blow up ash and produce a similar effect to whiteout (the ash will also stick to your windscreen, which will likely be wet from the water pickup). Dropping at some speed over an area is mostly used for cooling purposes after the flames are out, as a fire can stay underground for days. IR scanning is used to detect hotspots afterwards.
In valleys, be aware of the extra power required to get you out of the “hole” with a load on—buckets don't always release their load, especially if the connectors get wet when picking up.
Forest and moorland fires also require vast amounts of manpower, which are usually tired by the time they get to the fire from the long walk to get there, so you may be used as transport for fire-fighters and their equipment, as well as observation, where your passengers will have some rank and experience, since they will be directing ground forces from the air (this will be especially true for lesser-powered helicopters). Very often, you will be moving people in very short hops over rivers and streams.
One development of this is rappelling, which is the rapid deployment of fire crews by rope from a helicopter (and back in emergency) until the regular crews arrive.
You will also not necessarily be the only aircraft about. The combination of lots of smoke (and poor visibility), coupled with heat turbulence and other machines buzzing about could prove to be extremely dangerous – many people report it’s just like being in a war zone (the organised chaos only makes it more so), but if you've ever done the British Grand Prix or joined Biggin Hill circuit you should be alright.
Constant communications between machines (on the same frequency) are essential, especially if you are picking up from the same swimming pool (in practice, you will go through the bird dog if you want to change position). One pilot reported that the distance from a pond to the fire was so small as to only require a fast hover taxi between them both, which meant that oil temperatures began to redline, as there wasn’t enough airflow to cool things down (sometimes ash will clog the oil cooler). You will be tired, as well, after a couple of days continuous flying from dawn to dusk, though you probably won’t notice till afterwards, as adrenalin counts for a lot.
Upslope drops should be avoided as much as possible, and only be attempted by experienced crews, especially on low targets, as you will need more airspeed than normal to create a pull-up to clear the area with the load if necessary, without using extra power. Aside from trying to do a 180-degree pedal turn in a high hover out of ground effect, the resulting high power setting will likely fan the flames, as with a hover drop. It helps if you have a drop off place to one side, and approach with some airspeed, so you can climb with the cyclic, and turn one way or the other with the least power, depending on which way round your blades are going.
With downslope drops, you will not necessarily see the target until you clear the ridge, so you will need targets to line up on beforehand. For very steep slopes, try reducing speed before diving off the ridge, so you don’t end up going too fast. Cross-slope drops are OK, provided you remember where your rotor disk is. With North American blade rotation, keep downhill slopes on your right, so if the bucket doesn't open or you run out of power, you can drop the collective, put the nose down and be able to use the right pedal to take the strain off the tail rotor. Always approach at a 45°, unless you have a bit of height.
phil
Last edited by Heliport; 1st Jul 2002 at 12:11.