Slingloading & Longlining
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Disk Loading; Longline Slingshot
Disk loading: On final I like to load up the disk early, before reaching my spot. Bring in the power, stay on the edge of translation, let ground effect bring us to a stop. On the other hand, Buddy was telling me to float on in and bring in the power at, or just before the spot. Seems a bit late to me...
Longline slingshot: Another buddy suggested taking a run at it if I can't deadlift a load. Keep the line tight, back up 10ft or so, then let 'er rip. Pull the pole when right over the load, and let translation do the rest. Obvious caveat being don't try this if the load won't follow. Tethered lawn darts not allowed! As long as we're not overgross this shouldn't be too hard on the ship 'cuz we're nearing translation and need less power, eh? On the other hand inertia has a way of increasing the load effect...
Now, are my buddies onto something or just on something?
Longline slingshot: Another buddy suggested taking a run at it if I can't deadlift a load. Keep the line tight, back up 10ft or so, then let 'er rip. Pull the pole when right over the load, and let translation do the rest. Obvious caveat being don't try this if the load won't follow. Tethered lawn darts not allowed! As long as we're not overgross this shouldn't be too hard on the ship 'cuz we're nearing translation and need less power, eh? On the other hand inertia has a way of increasing the load effect...
Now, are my buddies onto something or just on something?
Last edited by Dick Mitten; 20th Jul 2002 at 04:15.
Interesting questions? If you are not " overgross".....then why won't the aircraft pick the load up? In ten feet....how much speed will you be able to put on.....and is that enough to get you into ETL? My thought has always been to pick the load straight up....if it won't go....then it is too heavy. I can explain an extra turn or too a whole lot better than I can a dropped or damaged load.
Power...Power...Power....get it in early....make the collective movement slow and steady......ideally....one slow constant pull to establish hover power just prior to establishing the hover attitude. That prevents overtorques, large power swings, and large pedal inputs......and if something isn't working right...you will know early on into the approach while you still have some height to use as trade goods for something you are lacking besides experience and ideas.
Try both ways...see which one serves your needs better....then make up your own mind as to which technique is better for you.
Try both ways...see which one serves your needs better....then make up your own mind as to which technique is better for you.
Using flare effect is great but if you wait until slecting the hover attitude to pull in the collective you are asking for trouble. The act of pushing the nose forward rotates the aircraft about its CofG and starts it accelerating downwards - now you need even more power to arrest the rate of descent as well as compensating for the loss of translational lift. Lots of pilots have overtorqued/heavy landed and worse trying this method which looks flashy but doesn't work.
If you are pushed for power coming to a free air hover eg to deliver a load on a long line then make a level transition to the hover as it uses less power than going forward and down to the hover.
As for taking a run at the load to get it airborne, I'm with SASless -you cannot be serious because if you can't lift it normally it's too heavy.
If you are pushed for power coming to a free air hover eg to deliver a load on a long line then make a level transition to the hover as it uses less power than going forward and down to the hover.
As for taking a run at the load to get it airborne, I'm with SASless -you cannot be serious because if you can't lift it normally it's too heavy.
Waiting for ground effect is the best way to retract your unretractable gear. On the final stage you will need much more power to come to hover. Due to the large control input, out of CG, the massive more NR drop, you will need the more power. More power -> more torque -> more pedal to stop rotating. Results easy, as said, in overtorqueing and/or bended metal. And think about your safety. On that kind of method you have no possibilities to recover the ship and going around. If something goes wrong your are trapped... 
Same procedure on your running slingload take off. If the ship is overloaded and you will press it in the air, it's the shortest way to come quickly down to mother earth. No safety on that way.
If you aren't able to lift the load straight up, what will you do if the load is hooked on an obstacle... And due to the increased forces you overrun structural limits. Don't be a fool and forget it. If you are paid for lifted loads, it's better to make some bucks less and stay alive.
Same procedure on your running slingload take off. If the ship is overloaded and you will press it in the air, it's the shortest way to come quickly down to mother earth. No safety on that way.
If you aren't able to lift the load straight up, what will you do if the load is hooked on an obstacle... And due to the increased forces you overrun structural limits. Don't be a fool and forget it. If you are paid for lifted loads, it's better to make some bucks less and stay alive.
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Its an easy question, with an easy way to check the answer.
Power in early means less rate of descent at the termination of the approach, and thus less power overshoot (extra power) rquired to stop the whole train in the hover. Recall that the higher rate of descent at low power (you are not floating in at low power, you are falling like a safe) must be countered by an upward acceleration (a need to climb up out of the descent) that needs more power.
Try it, use the engine temperature (T5, T4.5, TGT, EGT), have a buddy note the peak temp that you use during the approach and try then several different techniques. The lowest power approach is the one that is the sneakiest getting into the hover. This is also the best approach for avoiding LTE, for the same reason, less power means less tail rotor needed.
Power in early means less rate of descent at the termination of the approach, and thus less power overshoot (extra power) rquired to stop the whole train in the hover. Recall that the higher rate of descent at low power (you are not floating in at low power, you are falling like a safe) must be countered by an upward acceleration (a need to climb up out of the descent) that needs more power.
Try it, use the engine temperature (T5, T4.5, TGT, EGT), have a buddy note the peak temp that you use during the approach and try then several different techniques. The lowest power approach is the one that is the sneakiest getting into the hover. This is also the best approach for avoiding LTE, for the same reason, less power means less tail rotor needed.
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Suspicions confirmed!
Just as I suspected, those young lads (all named "Buddy" by the way) are a bit cocky. I'm a middle-aged geezer, rather take it a bit slower, come back for another turn.
SASless - On a hot day lifting barrels of fuel takes more power than on a cold day. Just 'cuz I can't lift it on a hot day doesn't mean I'm over-gross, and just 'cuz I CAN lift it on a cold day doesn't mean I'm NOT over-gross. See what I mean? Gotta get one of those weight indicating gadgets onto my hook... Anyways, thanks for the feedback. Always good to know that I'm right 'n they're... Buddies!
I'm not always super-precise when bringing the load in. If it's taken some monkey business to get it flying, it'll wanna come down like the proverbial load of...Buddies! Rather bring it in nice 'n easy, have the chance to reposition it or give it a gentle touch down if it wants to swing about too much.
Still interested in hearing from someone who has positive experience with the slingshot!
SASless - On a hot day lifting barrels of fuel takes more power than on a cold day. Just 'cuz I can't lift it on a hot day doesn't mean I'm over-gross, and just 'cuz I CAN lift it on a cold day doesn't mean I'm NOT over-gross. See what I mean? Gotta get one of those weight indicating gadgets onto my hook... Anyways, thanks for the feedback. Always good to know that I'm right 'n they're... Buddies!
I'm not always super-precise when bringing the load in. If it's taken some monkey business to get it flying, it'll wanna come down like the proverbial load of...Buddies! Rather bring it in nice 'n easy, have the chance to reposition it or give it a gentle touch down if it wants to swing about too much.
Still interested in hearing from someone who has positive experience with the slingshot!
Last edited by Dick Mitten; 20th Jul 2002 at 13:38.
Regarding "Slingshot"
I first heard it called a "Wenatchee Snatch" or a logging pick. It is basically used for loads that can be landed hard or are being picked at a higher altitude than the landing area, thus the pilot is planning (hoping) on having more power availble to stop the load at the bottom.
It is hard on just about everything. I firmly believe it is one reason that the Bell medium helicopters have such a dismal safety record when it comes to logging. Slipping. jolting loads are transmitted through the whole aircraft. Resulting in torque spikes to the power train. It does work, but it's way outside normal operations. I've done more than a few but no more. If I can reform any one can. And there is no reason for you to learn them other than to make an operator some money in the short term. Long term the additional maintenance will take care of the increased board foot or pound per hour profit.
It's best left to the old days because sooner or later it's going to get you or another pilot flying the machine.
I first heard it called a "Wenatchee Snatch" or a logging pick. It is basically used for loads that can be landed hard or are being picked at a higher altitude than the landing area, thus the pilot is planning (hoping) on having more power availble to stop the load at the bottom.
It is hard on just about everything. I firmly believe it is one reason that the Bell medium helicopters have such a dismal safety record when it comes to logging. Slipping. jolting loads are transmitted through the whole aircraft. Resulting in torque spikes to the power train. It does work, but it's way outside normal operations. I've done more than a few but no more. If I can reform any one can. And there is no reason for you to learn them other than to make an operator some money in the short term. Long term the additional maintenance will take care of the increased board foot or pound per hour profit.
It's best left to the old days because sooner or later it's going to get you or another pilot flying the machine.
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To expand a little on what has been said about disc loading:
If one was at high density alt. ( mountains in summer lets say), and you came in gliding and fast pulling pitch over the spot, there is a definite possibility in some machines that LTE will occur and you have used up your options. A hard landing with a right rotation could be the result.
Nevertheless, in any approach, taking your time and loading up the disc early is probably the best most of the time....unless you're a hotdog and you're by yourself and nobody nearby and its your own machine...... so what's the point?
Safety first.
If one was at high density alt. ( mountains in summer lets say), and you came in gliding and fast pulling pitch over the spot, there is a definite possibility in some machines that LTE will occur and you have used up your options. A hard landing with a right rotation could be the result.
Nevertheless, in any approach, taking your time and loading up the disc early is probably the best most of the time....unless you're a hotdog and you're by yourself and nobody nearby and its your own machine...... so what's the point?
Safety first.
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We are not talking about Disk Loading!
While this thread is discussing interesting stuff, the term disk loading has nothing to do with the approach technique we are discussing.
Disk loading ia a measure of the weight per square foot of rotor disk.
The technique we are discussing (and I am advocating) is one of a measured deceleration so that the power needed to hover is applied progressively as the approach is performed. It might be termed a "controlled power approach" a term I have used for about 20 years as I have taught the technique. The opposite of a controlled power approach is a "suck it all in at the bottom" approach.
Most approaches are actualy a blend of the two, but as power becomes more limited, the first becomes more advisable, I think.
Disk loading ia a measure of the weight per square foot of rotor disk.
The technique we are discussing (and I am advocating) is one of a measured deceleration so that the power needed to hover is applied progressively as the approach is performed. It might be termed a "controlled power approach" a term I have used for about 20 years as I have taught the technique. The opposite of a controlled power approach is a "suck it all in at the bottom" approach.
Most approaches are actualy a blend of the two, but as power becomes more limited, the first becomes more advisable, I think.
Mitten....you will notice I had "over gross" in quotes.....felt like leaving it simple.....basic idea is if you can't pick it up normally....then cut the load back...wait till you burn some fuel...come back when it is cooler...or better wind...or something. Your point about being overgross sure 'nuff is taken....and I am well aware of that. In the old Alouette you could overpitch due to being overgross and the machine handled just fine except for the overtorque on the tranny and tail rotor, et al.
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Good discussion!
Thanks to everyone for the comments. I'll see if some of this might rub off on the "Buddies".
SASless: Opps! Sorry I missed/misunderstood the quotes. Thanks for clarifying.
Cautious, and d**ned proud of it!
SASless: Opps! Sorry I missed/misunderstood the quotes. Thanks for clarifying.
Cautious, and d**ned proud of it!
Join Date: May 2001
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Dick Mitten,
Heard of the slingshot departure, morelike the HOTSHOT departure. The quickest way to destroy your chances of ever dying in bed. A unfortunately for many, the effects of such slingshots are not felt for a while, then, some poor guy (You maybe) will be doing his job on the day the helicopter says enough.
Anyone who preaches such departures is overstressing that airframe, i dont care what anyone says, if you cant lift it, dont lift it, ..................die in bed.
SL
Heard of the slingshot departure, morelike the HOTSHOT departure. The quickest way to destroy your chances of ever dying in bed. A unfortunately for many, the effects of such slingshots are not felt for a while, then, some poor guy (You maybe) will be doing his job on the day the helicopter says enough.
Anyone who preaches such departures is overstressing that airframe, i dont care what anyone says, if you cant lift it, dont lift it, ..................die in bed.
SL
Disc loading is what Nick said, a measure of the weight per square foot of rotor disc. ‘Loading the disc early’ is what you’re talking about, and I’m with the ‘load it early’ camp.
Sling shot departures can be brutal on the helicopter, require a great deal of finesse, and tend to be very unforgiving when they don’t work. Dick, I’ll respectfully disagree with one of your statements – “Just 'cuz I can't lift it on a hot day doesn't mean I'm over-gross”. It may very well mean that, for that density altitude. You’d have to refer to the HOGE charts. You are correct however in saying “just 'cuz I CAN lift it on a cold day doesn't mean I'm NOT over-gross.”
Die in bed. I like that.
Sling shot departures can be brutal on the helicopter, require a great deal of finesse, and tend to be very unforgiving when they don’t work. Dick, I’ll respectfully disagree with one of your statements – “Just 'cuz I can't lift it on a hot day doesn't mean I'm over-gross”. It may very well mean that, for that density altitude. You’d have to refer to the HOGE charts. You are correct however in saying “just 'cuz I CAN lift it on a cold day doesn't mean I'm NOT over-gross.”
Die in bed. I like that.
Inadvertant bucket releases
On another thread, John Eacott posted the following:
I recall that there were several last on last year's fires as well. Is this a BK117 issue, or do you think it is more common?
As our civil aviation authority, nor our transport safety board choose to publish a "crash comic" such as the Canadian "Vortex", we are left to learn lessons from overseas incidents and we have no means of identifying and rectifying trends.
Internationally, and Oz-wise, I am wondering how common the bucket drop really is.
On a serious side, there have been a lot of bucket drops this season, most of them equipment failures, rather than pilot error. We always fly with the cargo master Off, but have had two uncommanded releases earlier this season, which we tracked down to an inherent hook fault, when NSW NPWS BK also had two identical uncommanded releases.
As our civil aviation authority, nor our transport safety board choose to publish a "crash comic" such as the Canadian "Vortex", we are left to learn lessons from overseas incidents and we have no means of identifying and rectifying trends.
Internationally, and Oz-wise, I am wondering how common the bucket drop really is.
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Cargo Hooks
AFAIK Cargo hooks are certified equipment. Unfortunately they, for some reason, don't seem to get maintained in the same way as the rest of the aircraft. Although technically they should be. In this patch it is entirely feasible to operate over and sling over a built up area. It has happened for years and quite frankly is just not an issue of concern. It is the main operators business (95%) and not just occassional. Subsequently hooks get a lot of attention.
It seems that liability is covered adequately and there are cultural differences. The loads are all attached and rigged under the control of a licensed and trained "Flight Assistant". BTW these guys have an excellent training manual.
Mind you this is in a country where JAR Ops simply would not work and has been observed accordingly as well.
As an aside - next time you work with someone watch the movements of the hook with a Bambi on it especially on release with a little speed or when dropping in the water to pickup. Invariably it can be traced to the manual release cable being restrained too close or tight to the hook. Then again there are other gremlins - had a H300C once which would pickle when you turned on the landing light. EMF and spikes!
It seems that liability is covered adequately and there are cultural differences. The loads are all attached and rigged under the control of a licensed and trained "Flight Assistant". BTW these guys have an excellent training manual.
Mind you this is in a country where JAR Ops simply would not work and has been observed accordingly as well.
As an aside - next time you work with someone watch the movements of the hook with a Bambi on it especially on release with a little speed or when dropping in the water to pickup. Invariably it can be traced to the manual release cable being restrained too close or tight to the hook. Then again there are other gremlins - had a H300C once which would pickle when you turned on the landing light. EMF and spikes!
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There appears to be some good evidence that static electricity build up can cause inadvertant releases. Too much static can build up and flash across the release relay...
I have no personal evidence, but this has been pointed out as a pretty reasonable cause.
Anyone out there know any more on the subject?
I have no personal evidence, but this has been pointed out as a pretty reasonable cause.
Anyone out there know any more on the subject?
From Issue 3/2003, Aviation Safety Vortex (shameless plug)
21 January, 2002 AS350BA
Squamish, B.C.
TSB Occurrence No. A02P0017
The A-Star had just departed Squamish airport with a sling load of antennae on a long line with a remotely operated electric hook. The load was to be delivered to the top of Hospital Hill, about 6 NM SE. At approximately 800 ft, while over flying high voltage power lines, the load inadvertently released from the remote hook and fell into the wires. Company maintenance personnel inspected the installation and no defect was found. It is suspected that the electric release suffered electromagnetic interference from the proximity of the power line, and the company has replaced the release cable with ‘high impulse protected wire.’
This drives home the practice of never over flying people or property with a sling load. Last year we had nine reported events where the sling load didn’t make it to destination because of an inadvertent release. -Ed.
21 January, 2002 AS350BA
Squamish, B.C.
TSB Occurrence No. A02P0017
The A-Star had just departed Squamish airport with a sling load of antennae on a long line with a remotely operated electric hook. The load was to be delivered to the top of Hospital Hill, about 6 NM SE. At approximately 800 ft, while over flying high voltage power lines, the load inadvertently released from the remote hook and fell into the wires. Company maintenance personnel inspected the installation and no defect was found. It is suspected that the electric release suffered electromagnetic interference from the proximity of the power line, and the company has replaced the release cable with ‘high impulse protected wire.’
This drives home the practice of never over flying people or property with a sling load. Last year we had nine reported events where the sling load didn’t make it to destination because of an inadvertent release. -Ed.
The hooks that I referred to in the two BK117 incidents were Breeze A45 units. These are 30+ year old designs, and no longer supported by Breeze Eastern, as per Service Information Letter dated 26th April 2002. The fault is to do with tension on the emergency (manual) release, which appears to be interfaced with the auto release feature that was designed into the hook, but not used. The hook's fine in flight until <100lbs force, when it then 'auto releases', which was annoying when the Bambi went into a dam, irritating when turbulence dropped an empty bucket in cruise, and bl**dy impossible when NSW NPWS dropped a full bucket into the trees, and retrieved component parts. Plus, they were off the fire until they replaced the hook. I also have had an uncommanded release of a Siren hook, with an empty bucket, in cruise at 1500 feet during last season where the bucket hadn't been off the hook for over a week.
We've replaced our hooks with OBS Talon keeperless units, which are great. We have had to fabricate bumper rings to protect the hook, since the BK suspension system drops it (the hook) into the dirt and dust on every landing, which would soon wreck the unit. Re the Vortex comment about not flying over property, this is a requirement in Oz, under CAO's, but becomes an impossibility in urban fires, although every effort is made to minimise overflights in normal transit. We have a CASA approval against the relevant regs for ops over built up areas when fire fighting, but I'd hate to be the first to fight a legal action if a full bucket caused more damage than a fire
We've replaced our hooks with OBS Talon keeperless units, which are great. We have had to fabricate bumper rings to protect the hook, since the BK suspension system drops it (the hook) into the dirt and dust on every landing, which would soon wreck the unit. Re the Vortex comment about not flying over property, this is a requirement in Oz, under CAO's, but becomes an impossibility in urban fires, although every effort is made to minimise overflights in normal transit. We have a CASA approval against the relevant regs for ops over built up areas when fire fighting, but I'd hate to be the first to fight a legal action if a full bucket caused more damage than a fire