Helicopter underslung mission
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Helicopter underslung mission
What are the advantages of having a load indication system that can display your underslung load to you in the cockpit?What I mean is that even though more information never hurt anyone, but is that information very useful in light helicopter with max underslung capacity in the 1.5 ton regime. Is there anyone out there who has utilised such a system and tell me its pluses and minuses?
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Helicopter Underslung Mission
Ashkash, An external load weight indication system can be extremely useful in circumstances, for example, where the personnel preparing a load are 'non-helicopter' and not aware of the the weight limitations or have no means to weigh a load except by 'best guesstimatin' etc. Also, these personnel may not be aware of the flight charactaristics of 'high-density' and 'low-density' external loads. I once witnessed a knock-down, drag-out argument between a pilot and a building contractor because the pilot refused to undersling a sheet of plywood.
Over the years I have come across a couple of systems, if I remember correctly they were manufactured by a) Chadwick Inc, and b) Onboard Weighing Systems Inc.
The only 'minus' of such a system that I can think of is a) it adds weight to the helicopter, but not a lot, in a situation where helicopter minimum weight is very important, and b) the systen will require periodic calibration and maintenance.
Over the years I have come across a couple of systems, if I remember correctly they were manufactured by a) Chadwick Inc, and b) Onboard Weighing Systems Inc.
The only 'minus' of such a system that I can think of is a) it adds weight to the helicopter, but not a lot, in a situation where helicopter minimum weight is very important, and b) the systen will require periodic calibration and maintenance.
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The load cell is actually useful to tell you that the "1000 Kg" load that you have been assured has been carefully worked out and weighed is actually more like three times that weight, allowing you to gently place it back on the ground for adjustment!
That and the torque figures rapidly rising through the scale as you try to pull in power!!
That and the torque figures rapidly rising through the scale as you try to pull in power!!
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Ashkash, An external load weight indication system can be extremely useful in circumstances, for example, where the personnel preparing a load are 'non-helicopter' and not aware of the the weight limitations or have no means to weigh a load except by 'best guesstimatin' etc. Also, these personnel may not be aware of the flight charactaristics of 'high-density' and 'low-density' external loads. I once witnessed a knock-down, drag-out argument between a pilot and a building contractor because the pilot refused to undersling a sheet of plywood.
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The military Puma has a collective pitch gauge, rather than a torquemeter.
We also had a theoretical collective pitch graph, from which we could get a good idea of the AUW of the aircraft before and after load pick up and cross check the usl's weight.
We also had a theoretical collective pitch graph, from which we could get a good idea of the AUW of the aircraft before and after load pick up and cross check the usl's weight.
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Ref Saint Jacks comments, and others. I have rarely seen a medium helicopter (if it picks up one and a half ton on the hook its not a lighty any more) that does not have a weigh cell fitted.
The chances of the people loading the nets getting the weight right is slim, and when you are at the limits of what you can lift for a trip the weight information is indispensible.
The chances of the people loading the nets getting the weight right is slim, and when you are at the limits of what you can lift for a trip the weight information is indispensible.
So what torque did MA get to when he tried to sling load Germany ?
Heard about the story second hand, would like to know more. Last heard of MA about 4 years ago, ill having contracted a disease through drum skins. Anyone know if he's ok now ?
Heard about the story second hand, would like to know more. Last heard of MA about 4 years ago, ill having contracted a disease through drum skins. Anyone know if he's ok now ?
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You could always just buy an aircraft that was engineered to do the job...
YouTube - Amazing Russian Mi-26 Helicopter
YouTube - Amazing Russian Mi-26 Helicopter
The main benefit of such a system - along with suitable mirrors - is that it dispenses with the need for a (usually very heavy and overpaid) crewman who thinks it's his God given right to talk all the time (even when not required).
The main benefit of UAV's - without the need for suitable mirrors - is that it dispenses with the need for a (usually very heavy and overpaid) Pilot who thinks it's his God given right to talk all the time (even when not required).
Bring em on!
Bring em on!
The weight that a load indicator may show you can be subject to innumeral variations. There are two types, Those that show a second pilot or crewman what the actual weight is or the one you set and it tells you when you have gone over the figure. Neither are very accurate even though their actual weight indication is correct.
When you are in the initial stages it will indicate the increasing weight of the slinging gear as it comes off the ground. To pull the load off the ground requires the overcoming of inertia and in the hover the effect on the rotor wash on the load will falsify the figure. Transitioning to forward flight incorporates another batch of inertia and it also requires energy to pull it through the air. Aerodynamic effects dependant of the shape of the load may reduce or increase its apparant weight. The result is that you will be informed of an actual weight that may bear no relation to the planned weight.
One example. Lifting a bridge structure and positioning it. Actual weight 1725 kilos including plywood fins to ensure that it flies fore/aft in relation to the aircraft otherwise it was going nowhere. Continuous reading loadmeter indicates approx 1970 kilo in the hover then slowly down to 1800 at 45 knots. At 60 knots rapidly decreases down to 900 kilos as it starts flying. Continue at 50 knots/1650.
Another. Resupplying an island 125n.m. away in the Solomon Islands with a 332L. A heavy aircraft permantly fitted with internal overload and sponson tanks. Rations for a week for Australian police plus five drums of diesel in a net. The weight on the hook doesn't matter, it well within the limits but when you hook up you are at 20,000 lbs. Then you can lift the load and are at minimum fuel to get there and back. One slight inconvenience is that it is at +35C and ten miles south there is a mountain range over 5000ft. high that you have to cross to get to this island. There are valleys but there also permanent 8/8th cloud. No load guages on this but at 7,000ft/70knots it stops climbing. It is down to 18,500lbs in weight so it should still be soaring but the drag on the load is sufficient stop it. Once over the hill descending to 2,000ft at 15 degrees of pitch should give you 130knots. No chance, 90 at the best.
My only recommendation for a load guage would be to bin it. Ignorance is bliss.
When you are in the initial stages it will indicate the increasing weight of the slinging gear as it comes off the ground. To pull the load off the ground requires the overcoming of inertia and in the hover the effect on the rotor wash on the load will falsify the figure. Transitioning to forward flight incorporates another batch of inertia and it also requires energy to pull it through the air. Aerodynamic effects dependant of the shape of the load may reduce or increase its apparant weight. The result is that you will be informed of an actual weight that may bear no relation to the planned weight.
One example. Lifting a bridge structure and positioning it. Actual weight 1725 kilos including plywood fins to ensure that it flies fore/aft in relation to the aircraft otherwise it was going nowhere. Continuous reading loadmeter indicates approx 1970 kilo in the hover then slowly down to 1800 at 45 knots. At 60 knots rapidly decreases down to 900 kilos as it starts flying. Continue at 50 knots/1650.
Another. Resupplying an island 125n.m. away in the Solomon Islands with a 332L. A heavy aircraft permantly fitted with internal overload and sponson tanks. Rations for a week for Australian police plus five drums of diesel in a net. The weight on the hook doesn't matter, it well within the limits but when you hook up you are at 20,000 lbs. Then you can lift the load and are at minimum fuel to get there and back. One slight inconvenience is that it is at +35C and ten miles south there is a mountain range over 5000ft. high that you have to cross to get to this island. There are valleys but there also permanent 8/8th cloud. No load guages on this but at 7,000ft/70knots it stops climbing. It is down to 18,500lbs in weight so it should still be soaring but the drag on the load is sufficient stop it. Once over the hill descending to 2,000ft at 15 degrees of pitch should give you 130knots. No chance, 90 at the best.
My only recommendation for a load guage would be to bin it. Ignorance is bliss.
