As350 Hydraulic System Failures: too many??
Recollection of PREVIOUS accidents:
source: http://www.honoluluadvertiser.com/ap...703100330/1001
Regards
Aser
Causes of previous helicopter crashes include worn, rusty hydraulic pump, pilot error
• Probe's focus: hydraulics
By Jan TenBruggencate
Advertiser Staff Writer
Previous cases of hydraulic failure on helicopters include:
# An AS350BA helicopter operated by Heli USA that crashed near the Peach Springs, Ariz., airport after a hydraulic failure on Sept. 11, 2002. In this incident, the pilot reported the controls were not responding. Witnesses said the helicopter began spinning when it was 30 to 50 feet from the ground. In the hard landing, the main rotors cut off the helicopter's tail boom. One of six passengers received minor injuries, but the pilot and the other five were not hurt.
The National Transportation Safety Board investigation found that the helicopter's hydraulic pump had failed due to lack of lubricant, and that even though it had been serviced only 15 days earlier, the pump was severely worn and rusty.
"A metallurgical examination of the hydraulic pump revealed that it had failed due to the wearing away of the splines on the coupling sleeves. ... There was rust on the front retaining rings and bearings, which indicated that there was insufficient grease in the splines to retain it or lubricate the splines," the NTSB report said. It cited as causes of the crash the pilot's failure to follow correct procedures for a landing with hydraulic failure, Heli USA's faulty maintenance, as well as a manufacturing flaw in making part of the hydraulic pump.
# An AS350B3 operated by Native American Air Ambulance crashed near Scottsdale, Ariz., on Nov. 2, 2003, after the pilot inadvertently hit a hydraulic switch and was unable to prevent a resulting spin. Injuries were minor.
# A Texair Helicopters crash on May 24, 2000, in Patterson, La., with an AS350B2 in which hydraulic failure was listed as the cause. The pilot and single passenger suffered minor injuries when the helicopter flipped on its side on landing. Investigators found that the pilot had inadvertently turned off his hydraulics after a tail rotor failure.
# A Helinet Corp. AS350B crashed March 26, 2000, in Van Nuys, Calif., after a loss of hydraulics due to a mechanical failure. The helicopter rolled on its side, seriously injuring both the pilot and her passenger, a television news cameraman.
The NTSB said that the pilot, who was 5 feet 1 and weighed 108 pounds, should have landed as soon as possible, instead of flying back to her home airfield. She simply wasn't strong enough to control the helicopter for as long as she needed to for the flight, the NTSB said.
"The National Transportation Safety Board determines the probable causes of this accident as follows. The pilot's failure to land as soon as practical. ... Contributing to the accident was the pilot's physical stature and strength," the agency's report said, in part.
Reach Jan TenBruggencate at [email protected].
• Probe's focus: hydraulics
By Jan TenBruggencate
Advertiser Staff Writer
Previous cases of hydraulic failure on helicopters include:
# An AS350BA helicopter operated by Heli USA that crashed near the Peach Springs, Ariz., airport after a hydraulic failure on Sept. 11, 2002. In this incident, the pilot reported the controls were not responding. Witnesses said the helicopter began spinning when it was 30 to 50 feet from the ground. In the hard landing, the main rotors cut off the helicopter's tail boom. One of six passengers received minor injuries, but the pilot and the other five were not hurt.
The National Transportation Safety Board investigation found that the helicopter's hydraulic pump had failed due to lack of lubricant, and that even though it had been serviced only 15 days earlier, the pump was severely worn and rusty.
"A metallurgical examination of the hydraulic pump revealed that it had failed due to the wearing away of the splines on the coupling sleeves. ... There was rust on the front retaining rings and bearings, which indicated that there was insufficient grease in the splines to retain it or lubricate the splines," the NTSB report said. It cited as causes of the crash the pilot's failure to follow correct procedures for a landing with hydraulic failure, Heli USA's faulty maintenance, as well as a manufacturing flaw in making part of the hydraulic pump.
# An AS350B3 operated by Native American Air Ambulance crashed near Scottsdale, Ariz., on Nov. 2, 2003, after the pilot inadvertently hit a hydraulic switch and was unable to prevent a resulting spin. Injuries were minor.
# A Texair Helicopters crash on May 24, 2000, in Patterson, La., with an AS350B2 in which hydraulic failure was listed as the cause. The pilot and single passenger suffered minor injuries when the helicopter flipped on its side on landing. Investigators found that the pilot had inadvertently turned off his hydraulics after a tail rotor failure.
# A Helinet Corp. AS350B crashed March 26, 2000, in Van Nuys, Calif., after a loss of hydraulics due to a mechanical failure. The helicopter rolled on its side, seriously injuring both the pilot and her passenger, a television news cameraman.
The NTSB said that the pilot, who was 5 feet 1 and weighed 108 pounds, should have landed as soon as possible, instead of flying back to her home airfield. She simply wasn't strong enough to control the helicopter for as long as she needed to for the flight, the NTSB said.
"The National Transportation Safety Board determines the probable causes of this accident as follows. The pilot's failure to land as soon as practical. ... Contributing to the accident was the pilot's physical stature and strength," the agency's report said, in part.
Reach Jan TenBruggencate at [email protected].
Regards
Aser
Synopsis
The helicopter was positioning for forestry spraying operations and was being flown by a student pilot who was receiving type-rating instruction. The instructor simulated a hydraulic system failure by pressing the HYD TEST (hydraulic test) button. Whenthe student pilot began to experience control difficulties, the instructor took over and asked the student to turn the hydraulics back on. The student mistakenly selected the auxiliary hydraulics button, by which time the helicopter was uncontrollable in yaw. The instructor managed to reset the HYD TEST button, but hydraulic power was not restored. He was unable to prevent the rotation continuing so elected to place the machine on the ground before the situation worsened. The helicopter rolled onto its side upon touching down. Hydraulic failure is normally simulated in the AS350 series by depressing the HYD TEST button. This depressurises the system, and the three accumulators in the roll and pitch circuits will continue to provide hydraulic assistance long enough for the pilot to reduce speed to the safe operating range of between 40 and 60 knots. Once the accumulator pressure has been exhausted, the aircraft is effectively under manual control, and the pilot will feel significant loads on the controls. The flight manual actions for hydraulic failure are firstly to reduce collective pitch and adjust the airspeed to between 40 and 60 knots, and secondly to operate the Hydraulic Cut-Off switch on the collective lever. This switch serves to eliminate any residual pressure on the servo pistons, minimising the mechanical loads required to move the control linkages. It also cancels the warning horn, which sounds when hydraulic pressure is lost. The B2 model has an additional accumulator in the yaw control circuit. Operating the HYD TEST button depressurises this accumulator immediately, but in the case of an actual hydraulic failure, this accumulator remains pressurised indefinitely (according to the flight manual), even when the collective switch is operated. Simulating hydraulic failure in the B2 model by using the HYD TEST button will result in control loads being felt immediately in the yaw circuit, with the normal delay in the roll and pitch circuits. There is a note in the emergency section of the flight manual that states: "Do not press the HYD TEST button; this will cause immediate depressurisation of the accumulator and the resulting control loads may be heavy." In this occurrence, when the instructor simulated hydraulic failure by means of the HYD TEST button, the student would have immediately felt control loads though the yaw pedals but normal forces on the cyclic and collective until the accumulator pressures discharged. By the time the latter occurred, he should have had the speed within the recommended range and operated the Hydraulic Cut-Off switch on the collective lever. However, the collective switch was not operated in this case, and the instructor did not reset the HYD TEST button until after control difficulty was experienced. This action did not immediately restore the hydraulic system to its normal operation. The instructor was of the opinion that this was due to the time the accumulators took to recharge.
10,000 hour pilot with approx 4000 on type.
Looked at the BEA site in France and back as far as 1997 there has never been an accident recorded with the 350 involving the hydraulics.
A thing to remember with all of this is if you have a hydraulic pump failure (in a machine with the yaw compensator) and engage the "HYD TEST" button, you have cooked your goose with the yaw compensator. You cannot get the assistance of the compensator back as you have depressurised it and as you have no pump there is no way of re-pressurising it!! The yaw channel forces on reduction of speed will be larger than you really need or may be able to contend with.
10,000 hour pilot with approx 4000 on type.
Looked at the BEA site in France and back as far as 1997 there has never been an accident recorded with the 350 involving the hydraulics.
A thing to remember with all of this is if you have a hydraulic pump failure (in a machine with the yaw compensator) and engage the "HYD TEST" button, you have cooked your goose with the yaw compensator. You cannot get the assistance of the compensator back as you have depressurised it and as you have no pump there is no way of re-pressurising it!! The yaw channel forces on reduction of speed will be larger than you really need or may be able to contend with.
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Hi all,
just received a factory transition for the B3.
The instructor would not use the HYD button on the console to simulate a failure, but hit the warning light button (incl. the gong) and call out the emergency.
If it was to be a HYDR failure, I would slow down to 65kts and switch off HYD at the collective and then slow further to about 55 to 60.
Reinforced with a video clip from some botched test flight in Mexico, I was indoctrinated to NEVER touch the HYD button of the console in flight when a real HYD failure is suspected, as it would render the TR basically unusable.
The only time ever one should touch the HYD-console button (in flight) is when a loss of TR-control is suspected (pedals stuck, etc.) In this case pressing the console-HYD-button will return the pedal/TR position to somewhere neutral.
After that - 4-6 sec, one would reset the HYD button in the up/on position to restore hydraulics to the rest of the system.
The resulting approach was done at about 75 kts with left slip, slowing down for a running landing at about 35-25 kts, but with hydraulic control on cyclic and collective.
It was mentioned that a few accidents (like the one news-copter in New York) where due to inadequate pilot training:
Something goes wrong with the hydraulics and for lack of knowledge they just hit "some" hydraulic button, with resultant loss of TR-control.
If in a B3 and suspecting anything wrong with hydraulics, the collective is the only place to switch them!!
3top
just received a factory transition for the B3.
The instructor would not use the HYD button on the console to simulate a failure, but hit the warning light button (incl. the gong) and call out the emergency.
If it was to be a HYDR failure, I would slow down to 65kts and switch off HYD at the collective and then slow further to about 55 to 60.
Reinforced with a video clip from some botched test flight in Mexico, I was indoctrinated to NEVER touch the HYD button of the console in flight when a real HYD failure is suspected, as it would render the TR basically unusable.
The only time ever one should touch the HYD-console button (in flight) is when a loss of TR-control is suspected (pedals stuck, etc.) In this case pressing the console-HYD-button will return the pedal/TR position to somewhere neutral.
After that - 4-6 sec, one would reset the HYD button in the up/on position to restore hydraulics to the rest of the system.
The resulting approach was done at about 75 kts with left slip, slowing down for a running landing at about 35-25 kts, but with hydraulic control on cyclic and collective.
It was mentioned that a few accidents (like the one news-copter in New York) where due to inadequate pilot training:
Something goes wrong with the hydraulics and for lack of knowledge they just hit "some" hydraulic button, with resultant loss of TR-control.
If in a B3 and suspecting anything wrong with hydraulics, the collective is the only place to switch them!!
3top
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If you don't like the single hydraulics on the B3, get the dual hydraulics. (Should be standard equipment if you ask me
)
Or go fly a 407 ,which they say chops its own tail off, or a 206L which won't carry the same payload, or a Koala.........(ahhh shucks- I can't find anything wrong there except for the uncomfortable seats)
)Or go fly a 407 ,which they say chops its own tail off, or a 206L which won't carry the same payload, or a Koala.........(ahhh shucks- I can't find anything wrong there except for the uncomfortable seats)
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The button is called HYD TEST. In the FLight Manual we got for the course it is still called ACCU TEST.
You are right, it is the accumulator test circuit.
According to the instructor, some accidents happened, because less than well trained pilots "paniced" and pressed "whatever" HYD button when the hydraulics failed.
By switching the collective HYD switch off you get non-hydraulic control back, but not on the TR, as the compensator is depleted too - that would only apply if you have a TR-control loss and want the pedals/TR somewhere centered, you still don't get control back, but you have a chance to run it on.
Without hydraulics this is going to be a hard game. (...as was wit the NY newscopter - this one went around a few times, before "coming to a stop"...)
You are also adviced to land as soon as possible if you have a HYD failure, because you will fatigue in short order.
My instructor said 2 min without HYD every day will take care of any workout needs you have!!
)
3top
PS: Watch the B3, this beast will destroy any piloting skills you might have had - there is just NEVER any lack of power - just pull collective. If you get just somewhere near the yellow arc you know you are severly overloaded)
Also the Koala is no good for tall pax, and have yet to figure out where 6 pax would put all their feet....
You are right, it is the accumulator test circuit.
According to the instructor, some accidents happened, because less than well trained pilots "paniced" and pressed "whatever" HYD button when the hydraulics failed.
By switching the collective HYD switch off you get non-hydraulic control back, but not on the TR, as the compensator is depleted too - that would only apply if you have a TR-control loss and want the pedals/TR somewhere centered, you still don't get control back, but you have a chance to run it on.
Without hydraulics this is going to be a hard game. (...as was wit the NY newscopter - this one went around a few times, before "coming to a stop"...)
You are also adviced to land as soon as possible if you have a HYD failure, because you will fatigue in short order.
My instructor said 2 min without HYD every day will take care of any workout needs you have!!
)3top
PS: Watch the B3, this beast will destroy any piloting skills you might have had - there is just NEVER any lack of power - just pull collective. If you get just somewhere near the yellow arc you know you are severly overloaded
)Also the Koala is no good for tall pax, and have yet to figure out where 6 pax would put all their feet....
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In January 2003 there was a fatal AS 350 B2 accident in Canada. The pilot was very experienced but lost control.
The conclusion from the Transportation Safety Board of Canada (TSB):
Causes and Contributing Factors
1)After experiencing a hydraulic system failure, the helicopter departed controlled flight and crashed while manoeuvring for landing. The reason for the departure from controlled flight could not be determined.
...
Full report :A03O0012
http://www.tsb.gc.ca/en/reports/air/...2/A03O0012.asp
The conclusion from the Transportation Safety Board of Canada (TSB):
Causes and Contributing Factors
1)After experiencing a hydraulic system failure, the helicopter departed controlled flight and crashed while manoeuvring for landing. The reason for the departure from controlled flight could not be determined.
...
Full report :A03O0012
http://www.tsb.gc.ca/en/reports/air/...2/A03O0012.asp
My instructor said 2 min without HYD every day will take care of any workout needs you have!!
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beefer,
you are right, "workout" will need some other than 60kt speed.
We did hover landings and take-offs without hydraulics.
Instructor said, it is not recommended, but one could even ferry a helo to the shop if necessary (wityhout hydraulics).....
3top
you are right, "workout" will need some other than 60kt speed.
We did hover landings and take-offs without hydraulics.
Instructor said, it is not recommended, but one could even ferry a helo to the shop if necessary (wityhout hydraulics).....
3top
>
We did hover landings and take-offs without hydraulics.
Instructor said, it is not recommended, but one could even ferry a helo to the shop if necessary (wityhout hydraulics).....
<
Factory school operating in direct violation of the RFM? We might have found the root of the Astar's reputation for misbehaving hydraulics.
We did hover landings and take-offs without hydraulics.
Instructor said, it is not recommended, but one could even ferry a helo to the shop if necessary (wityhout hydraulics).....
<
Factory school operating in direct violation of the RFM? We might have found the root of the Astar's reputation for misbehaving hydraulics.
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Jim,
don't get me wrong or get the instructor in trouble.
Certainly the RFM says "no", but there is a lot of things that say "no" for legal reasons, that where okay before.
You may not believe it, but there are places you cannot repair a ship, because it is not accessable, but by helo. If there is one onthe only place to land you are done.
You might walk in, but if it is possible, get a ferry permit and fly it out....
(if you know the airframe can do it without a - further - problem)
3top
don't get me wrong or get the instructor in trouble.
Certainly the RFM says "no", but there is a lot of things that say "no" for legal reasons, that where okay before.
You may not believe it, but there are places you cannot repair a ship, because it is not accessable, but by helo. If there is one onthe only place to land you are done.
You might walk in, but if it is possible, get a ferry permit and fly it out....
(if you know the airframe can do it without a - further - problem)
3top
Last edited by 3top; 24th May 2007 at 18:19.
"Just a pilot"
No flipping way that I'm taking an AS350 off the ground with malfunctioning hydraulics, period. Yes, in my experience, it's flyable with the boost off, but that's entirely beside the point. Emergencies are best handled on the ground, and compromised controls qualify as an emergency. Taking off into an emergency is STUPID, even if it's not illegal where you are.
Really sorry about grounding the aircaft a few days hike away from the road, but that's what I'm paid to do- make the hard and inconvenient calls. This aircraft regularly kills pilots with hydraulics failures, and I have no wish to find out why.
Rant mode off...
Really sorry about grounding the aircaft a few days hike away from the road, but that's what I'm paid to do- make the hard and inconvenient calls. This aircraft regularly kills pilots with hydraulics failures, and I have no wish to find out why.
Rant mode off...
>
(if you know the airframe can do it without a - further - problem)
<
Interesting slippery slope you’re landing on there. At what point, do you start to follow regulations?
(if you know the airframe can do it without a - further - problem)
<
Interesting slippery slope you’re landing on there. At what point, do you start to follow regulations?
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Jim,
I am following regs to the point, we are talking emergency here, are we?
In my end of the world the authorities take the regs rather serious, but they do allow for emergencies, even when not airframe related.
E.g. There is no VFR/single -night flying for helicopters here, cut-off is Sunset. However I (and other helo pilots) had various times atended to medical emergencies on the ground and the returnflight ended definitely after hours (up to 2.5 hrs into the night) - no legal problems in these cases, mostly not even a report requested - no one here dares to declare a medical flight and land on the only hospital helipad in town for fun!
Devil, maybe you haven't been in a "situation" before, I was - luckily without any emergency at this point.
Wet day - put geologists onto a gravel bed in a river (about 1 foot) above the water, at that the precise spot, you cannot get away, unless you are a supreme free climber (or Spiderman) or have rafting equiment with you.
One of them is his 60s and has a bad hip.
Before the rotor came to a stop I realised that the river was rising (again).
I restarted immediatly and recalled the 2 scientist (taking water samples).
By the time I was ready for take off, I had the skids under water.... (about 2 min, whatever it takes to start an R-44 and load 2 pax and get fully engaged and to 100% rrpm)
If you are on the spot, you will try the lesser of 2 evils.
Given my (so far very little) experience in the B3 and the practised maneuvers during the transition course, I would definitely try to take the helo to a different spot.
Also the Canadian accident mentioned earlier in this thread may have had an electrical problem, that could have rendered the hyd switch on the collective (hydr. cut-off) un-usable - as mentioned in the report.
If I experience a hydr. problem in the air and deal with it in a manner to keep flying (switch off HYD on collective) and the bird is flyable, where is the problem, except having selected the wrong place to land the first time.....
3top
I am following regs to the point, we are talking emergency here, are we?
In my end of the world the authorities take the regs rather serious, but they do allow for emergencies, even when not airframe related.
E.g. There is no VFR/single -night flying for helicopters here, cut-off is Sunset. However I (and other helo pilots) had various times atended to medical emergencies on the ground and the returnflight ended definitely after hours (up to 2.5 hrs into the night) - no legal problems in these cases, mostly not even a report requested - no one here dares to declare a medical flight and land on the only hospital helipad in town for fun!
Devil, maybe you haven't been in a "situation" before, I was - luckily without any emergency at this point.
Wet day - put geologists onto a gravel bed in a river (about 1 foot) above the water, at that the precise spot, you cannot get away, unless you are a supreme free climber (or Spiderman) or have rafting equiment with you.
One of them is his 60s and has a bad hip.
Before the rotor came to a stop I realised that the river was rising (again).
I restarted immediatly and recalled the 2 scientist (taking water samples).
By the time I was ready for take off, I had the skids under water.... (about 2 min, whatever it takes to start an R-44 and load 2 pax and get fully engaged and to 100% rrpm)
If you are on the spot, you will try the lesser of 2 evils.
Given my (so far very little) experience in the B3 and the practised maneuvers during the transition course, I would definitely try to take the helo to a different spot.
Also the Canadian accident mentioned earlier in this thread may have had an electrical problem, that could have rendered the hyd switch on the collective (hydr. cut-off) un-usable - as mentioned in the report.
If I experience a hydr. problem in the air and deal with it in a manner to keep flying (switch off HYD on collective) and the bird is flyable, where is the problem, except having selected the wrong place to land the first time.....
3top
"Just a pilot"
3top-
I started flying in '69 as a US Army helo pilot, 1st duty assignment- VietNam. My callsign while there is the source of my forum name, "Devil 49". I've been in a situation or two.
I'm not new to the type being discussed, either. Over the years, I've gotten something on the order of:
5000 hours (over 15 years) in the TwinStar/AStar;
approx 30,000 landings in the airframe;
Flown EMS in it for the last 6 years, and I've seen people die in it;
And I've had the occasional failure in the type. It's my favorite of all the helicopters I've flown.
I'll repeat, I've been in a situation or two, and I would so leave the broken aircraft to fend for itself, so quickly, that it's not funny. Sorry about the couple days hike in or hoist down to fix it, but...
As to passengers and any life and death scenarios imaginable, that's an individual call. As we say in EMS, I won't kill 4, 3 or even 2 trying to save 1. Add the fact that taking passengers aboard a disabled aircraft is a violation of professional trust.
One is casual regarding airworthiness at one's own peril. It tends to become a fatal habit, in my experience. This aircraft regularly kills pilots dealing with hydraulic problems. I have to believe that in all those events, there's been at least one pilot who was as good as I am. It can happen to me, if I let it.
I started flying in '69 as a US Army helo pilot, 1st duty assignment- VietNam. My callsign while there is the source of my forum name, "Devil 49". I've been in a situation or two.
I'm not new to the type being discussed, either. Over the years, I've gotten something on the order of:
5000 hours (over 15 years) in the TwinStar/AStar;
approx 30,000 landings in the airframe;
Flown EMS in it for the last 6 years, and I've seen people die in it;
And I've had the occasional failure in the type. It's my favorite of all the helicopters I've flown.
I'll repeat, I've been in a situation or two, and I would so leave the broken aircraft to fend for itself, so quickly, that it's not funny. Sorry about the couple days hike in or hoist down to fix it, but...
As to passengers and any life and death scenarios imaginable, that's an individual call. As we say in EMS, I won't kill 4, 3 or even 2 trying to save 1. Add the fact that taking passengers aboard a disabled aircraft is a violation of professional trust.
One is casual regarding airworthiness at one's own peril. It tends to become a fatal habit, in my experience. This aircraft regularly kills pilots dealing with hydraulic problems. I have to believe that in all those events, there's been at least one pilot who was as good as I am. It can happen to me, if I let it.
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D49,
thanks for the numbers.
I pull the ferry permit off the list (wasn't a smart one to begin with - if I can get the permit, I can get the mechanic....).
No intentions to load anybody on the machine, they would be there long before it happened.
Note taken about airworthiness - was there, gott'n away with it. Am rather very intolerant when it comes to airworthiness today (I am also working for a different company now....).
Certainly hope to never have to put my emergency training to the real test (did that before, I hope once is enough....).
Details, I am only assuming a simple belt failure - no pressure - switches working - bird keeps flying controlable....
If hydraulics freeze/lock/jam you can't do anything than prey anyway...
I envy you for your flight training, though not for your overseas tour after.
Got enough "learned from this" experiences without the heavymetal air....
Fin and Jim,
mentioning slippery slope:
.. did it ever happen to you, that you arrived on a site and it turned out to be to steep or slippery? What you do then with HYD out, but flyable?
I know we can dream up scenarios all day, but you know what? Actually not a bad idea, because it does make you think - what if?
Thinking about "interesting" landing-sites I ran into, I do ask myself what I would/could do if an emergency would occur/or had occured on approach...
The river here is for real, just so happened the helo was okay (... and has a "no action needed" HYD failure mode).
I had other scientists repeatedly on such a remote pinacle location, there IS NO walk out ..... (D49, where I live you are lucky IF they find you, and IF the winch works....)
enough,...
3top
thanks for the numbers.
I pull the ferry permit off the list (wasn't a smart one to begin with - if I can get the permit, I can get the mechanic....).
No intentions to load anybody on the machine, they would be there long before it happened.
Note taken about airworthiness - was there, gott'n away with it. Am rather very intolerant when it comes to airworthiness today (I am also working for a different company now....).
Certainly hope to never have to put my emergency training to the real test (did that before, I hope once is enough....).
Details, I am only assuming a simple belt failure - no pressure - switches working - bird keeps flying controlable....
If hydraulics freeze/lock/jam you can't do anything than prey anyway...
I envy you for your flight training, though not for your overseas tour after.
Got enough "learned from this" experiences without the heavymetal air....
Fin and Jim,
mentioning slippery slope:
.. did it ever happen to you, that you arrived on a site and it turned out to be to steep or slippery? What you do then with HYD out, but flyable?
I know we can dream up scenarios all day, but you know what? Actually not a bad idea, because it does make you think - what if?
Thinking about "interesting" landing-sites I ran into, I do ask myself what I would/could do if an emergency would occur/or had occured on approach...
The river here is for real, just so happened the helo was okay (... and has a "no action needed" HYD failure mode).
I had other scientists repeatedly on such a remote pinacle location, there IS NO walk out ..... (D49, where I live you are lucky IF they find you, and IF the winch works....)
enough,...
3top
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http://www.aaib.dft.gov.uk/sites/aai...il__g_bzvg.cfm
If this link works it will take you to the AAIB report which explains that one of the factors of this accident was the HYD TEST button being left depressed, thereby leaving the tail rotor accumulator depleted, during hydraulic failure training.
If this link works it will take you to the AAIB report which explains that one of the factors of this accident was the HYD TEST button being left depressed, thereby leaving the tail rotor accumulator depleted, during hydraulic failure training.
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The training procedure calls for pressing the HYD-TEST, Student reacts by slowing to about 60kts and switching off HYD on the collective. Instructor switches HYD-TEST back on (up-position).
My instructor prefers NOT to use the HYD-TEST button in the air, except for the loss of TR-control procedure.
He will only push the Warning-lights-button and call out "Hydraulic Failure", Student reacts by slowing to 60 kts and switching off collective HYD.
Reasons:
a) If correctly tested at start-up the accus should provide enough pressure and time to slow to 60 kts, so this should be transparent, whether the HYD-TEST is pressed or not.
b) Training is to learn procedures and habits. By NOT using the HYD-TEST with HYD-failure training he avoids a possible confusion when a real one hits.
He does emphazise to "Never touch the HYD-TEST in the air, except for TR-control loss!"
(First round of practise I forgot about it and would not know how to procede with the TR-control-loss procedure, but for sure I had it marked "to never touch HYD-TEST in the air....")
c) If for any reason the HYDs suffer any damage or incident while practising HYD-failures, the TR stays controlable and a non-HYD landing should be a non-event. With HYD-TEST pressed or locked for any reason (CB popped??), it would become a TR-control-loss + HYD-loss approach/landing = very heavy and very tough...
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My instructor prefers NOT to use the HYD-TEST button in the air, except for the loss of TR-control procedure.
He will only push the Warning-lights-button and call out "Hydraulic Failure", Student reacts by slowing to 60 kts and switching off collective HYD.
Reasons:
a) If correctly tested at start-up the accus should provide enough pressure and time to slow to 60 kts, so this should be transparent, whether the HYD-TEST is pressed or not.
b) Training is to learn procedures and habits. By NOT using the HYD-TEST with HYD-failure training he avoids a possible confusion when a real one hits.
He does emphazise to "Never touch the HYD-TEST in the air, except for TR-control loss!"
(First round of practise I forgot about it and would not know how to procede with the TR-control-loss procedure, but for sure I had it marked "to never touch HYD-TEST in the air....")
c) If for any reason the HYDs suffer any damage or incident while practising HYD-failures, the TR stays controlable and a non-HYD landing should be a non-event. With HYD-TEST pressed or locked for any reason (CB popped??), it would become a TR-control-loss + HYD-loss approach/landing = very heavy and very tough...
3top