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-   -   Hydraulics failure- helicopters (https://www.pprune.org/rotorheads/614247-hydraulics-failure-helicopters.html)

pilot_tolip 11th Oct 2018 15:32

Hydraulics failure- helicopters
 
Who's got any real world experience with in-flight hydraulic failure? Not simulated/training hydraulics off - but sudden real-world failure. What were your experiences with the failure of hydraulics? I'm interested to hear your experiences so I can learn from you. Thanks

SASless 11th Oct 2018 16:53

It all depends upon the aircraft, it’s systems, and where you are re landing sites.

Gordy 11th Oct 2018 17:19


Originally Posted by pilot_tolip (Post 10271360)
Who's got any real world experience with in-flight hydraulic failure?

Had hydraulic failure in an Astar in an out of ground effect hover at 1,000', me plus 6 passengers over Napali coast in Hawaii back in 2002. 27nm from Lihue airport. Had the front seat pax hold the pressure on the cyclic to save my arm strength for the landing 30 minutes later. I did tell my pax what was happening, (kinda hard to hide when the horn goes off for 25 seconds). Flew back, did shallow approach to a "slow" quick stop flare to the ground. Not a huge deal---just do what you do in training. Mine was caused by the failure of the A/C belt which then took out the hydraulic belt.

Take aways: Always declare an emergency as you will get priority handling and always take it to a hard surface so the skids can slide if needed without digging in---I touched down from a hover--but I have been trained to do that.

timprice 11th Oct 2018 17:36

Its not how you have been trained! its what's in the Flight manual, I am fed up with people thinking they are better than the manufacturer, follow the flight manual (hopefully that was how you where trained as per flight manual)
Once had hydraulic runaway on one servo in Jetranger many moons ago, cyclic kept motoring aft, just switched off hydraulics and landed.:ok:

Thomas coupling 11th Oct 2018 17:43

Utility hyd failure in a S61.
The MGB cooler fan drive belt(of which there are two) - snapped and severed a utility hyd pipe running alongside. The hyd supplied the undercarriage.
Had 3 MAJOR problems:
1. Back of the cab filled up with hyd mist expelling @ 3000psi!! As you know, hyd mist is a carcinogenic, so all the back seat crew had to come up front as we vented the rear of the cab.
2. No U/C. So RTB and hovered for 15 mins while we blew the gear down and dropped a crewman out the back to pin the gravity fed U/C before landing.
3. No MGB cooling. Flew the last few minutes of the sortie with the gauge just shy of max (115 degrees from memory). Caption lit during our hover.

Gordy 11th Oct 2018 18:14


Originally Posted by timprice (Post 10271476)
Its not how you have been trained! its what's in the Flight manual, I am fed up with people thinking they are better than the manufacturer, follow the flight manual (hopefully that was how you where trained as per flight manual)

Errrr, the flight manual is created for people working from airports---I normally see an airport a few times a year, the rest of the time I operate from a pad or field in the middle of nowhere, hence we train for the conditions we will likely encounter. Sometimes the flight manual does not keep up with reality due to "potential litigation". Clearly I need to find a higher horse.

Look at all the accidents that occur doing Hyd off in an Astar---if only they were taught correctly.

Flyting 11th Oct 2018 18:23

Had one in a Bell 205 IFR @ 12500' somewhere over Nigeria on a ferry flight.
With horrific noises coming from the back we elected to make an emergecy desent and land in an opening in the bush. Made an inspection (with rotors running) and then left the Hyd off and flew 90min to the next airport. Ended up with a Popeye arm after that!

GrayHorizonsHeli 11th Oct 2018 18:34

Once I ate too much KFC and while driving back to the city had a blowout of the number 2 seal....Oh wait, sorry, thats a different kind of hydraulics.

SASless 11th Oct 2018 19:49

I do so love "Cook Book " Pilots....who must lead a very sheltered existence. (Not referring to Gordy of course!)

Flying, On some aircraft I found applying some pressure to the cyclic in the direction you wanted it to move and then letting the feedback pulses to move it for you to be far easier than making like Popeye after a Can of Spinach or Charles Atlas.

The 206, 205 (single hydraulics), 58T and others generally liked that method.

The 58T's Collective used to make me feel like I was carrying the aircraft around in my left hand!

A flying Buddy and I in Tactical Training in a UH-1D had a hydraulics failure and flew the thing back to Home Plate.....the Cyclic was a bit stiff but manageable but the Collective was very...very...very easy up.....and a bugger bear to move down even with two of us grunting and straining against the seatbelts.

In a 206 in Iran.....at a Bush site....had a Collective freeze tighter than the Black Sardine's purse clasp. Fortunately it was at a power setting that allowed for a very slow speed run on landing at the normal parking spot.

I did. have one hydraulic fed cockpit fire in a Chinook that was a bit sporty.

Gordy 11th Oct 2018 21:42


Originally Posted by SASless (Post 10271569)
I do so love "Cook Book " Pilots....who must lead a very sheltered existence.

Me too.....


Originally Posted by SASless (Post 10271569)
A flying Buddy and I in Tactical Training in a UH-1D had a hydraulics failure and flew the thing back to Home Plate.....the Cyclic was a bit stiff but manageable but the Collective was very...very...very easy up.....and a bugger bear to move down even with two of us grunting and straining against the seatbelts.

The two Hueys I fly have the same issue, we have played with the rigging but almost impossible to get rid of it....basically have to get the thing to a hover, (higher pitch setting), and then lean all my weight on the collective to get it down.

In training we turn the Hydraulics off in a 150' hover simulating the failure right as you pick up the long line load, and take it straight back down in a Bell product, and use the accumulators in the Astar to get forward speed and bring it back shallow approach to a hover landing----simulating our only "pad" to land on. We use former factory pilots for our outside vendor training---they do it day in day out and really do teach you to be comfortable with the machine.

SAS---as you know I had the stuck pedal years ago----had no clue what I was doing, (former company with no training), but got it down. Have since practiced it every year since and feel confident I would do better now.

For those still reading, I had a wire strike 2 weeks ago and survived, cut a 60kv 3 phase line with the blades on one and the other two went into the wire cutters---FWIW, they do work.

krypton_john 11th Oct 2018 22:21


Originally Posted by Gordy (Post 10271642)

For those still reading, I had a wire strike 2 weeks ago and survived, cut a 60kv 3 phase line with the blades on one and the other two went into the wire cutters---FWIW, they do work.

Isch! Gives me nightmares.

SASless 11th Oct 2018 22:31

Fellows....and Ladies too.....if ever you get near Gordy.....please do rub his shoulder an pray some of his good luck rubs off on you!:D

There's plenty of ways of getting killed in our business....and Wires will straight up kill you!:{

Gordy beat the house big time two weeks ago!:eek:

Gordy 11th Oct 2018 22:31


Originally Posted by krypton_john (Post 10271661)
Isch! Gives me nightmares.

Me too....

https://abc7news.com/helicopter-stri...utage/4354526/

Unlike the article stated, I hit the ones going above me, not the ones I was patrolling. They were not marked and were about 200' off the ground.

I'm not welcome in Calistoga or Middletown anymore after cutting their power for a few hours...:cool::cool:

PAXboy 11th Oct 2018 23:48

Did the unmarked cables belong to the same utility as the ones you were patrolling? Whose responsibility is it to update the maps given to you and other line inspectors?
Lastly, for those of us that keep away from 60kv lines :eek: where are the wirecutters? They will have to work damm fast!

SASless 12th Oct 2018 00:18

Ingrates the lot of them.....look how look how much money you saved them on their electric bills!

krypton_john 12th Oct 2018 00:21

Seems like a line crossing the inspected line is a super risk as you're watching the line you are inspecting and less likely to spot the cross line with which you've been placed in a certain collision course. Nasty combination.

How did the blades fare? Am curious to know how well the wire cutters worked - did you just slice through without feeling anything or ... ?

EMS R22 12th Oct 2018 01:12


Originally Posted by Gordy (Post 10271511)
Errrr, the flight manual is created for people working from airports---I normally see an airport a few times a year, the rest of the time I operate from a pad or field in the middle of nowhere, hence we train for the conditions we will likely encounter. Sometimes the flight manual does not keep up with reality due to "potential litigation". Clearly I need to find a higher horse.

Look at all the accidents that occur doing Hyd off in an Astar---if only they were taught correctly.

I agree Gordy. Most of the time I have now where flat to run a machine on to.

Good to practice different scenarios with an experienced instructor.

I too have cut wires with a wire strike kit. Not a scratch on the machine.They work.

Twist & Shout 12th Oct 2018 02:29


Originally Posted by EMS R22 (Post 10271738)
I agree Gordy. Most of the time I have now where flat to run a machine on to.

Good to practice different scenarios with an experienced instructor.

........................

Not without its risks.

https://www.atsb.gov.au/publications...r/ao-2017-109/

RVDT 12th Oct 2018 03:38

And another fatal in the UK 6 months prior to the one in Oz.

G-MATH

RVDT 12th Oct 2018 03:46


A flying Buddy and I in Tactical Training in a UH-1D had a hydraulics failure and flew the thing back to Home Plate.....the Cyclic was a bit stiff but manageable but the Collective was very...very...very easy up.....and a bugger bear to move down even with two of us grunting and straining against the seatbelts.
Single HYD 205's had an adjustment to the inboard strap fitting so you could take the load off at about mid range Q. Not everyone used to be aware of it and some were pretty hard to fly HYD OFF.
Was a little worm drive arrangement from memory. HYD OFF single hydraulics 205's were hardly noticeable in the cyclic above about 30 knots from memory. Also depended if the blades were swept at all.


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