Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

AS350 Astar/Squirrel

Wikiposts
Search
Rotorheads A haven for helicopter professionals to discuss the things that affect them

AS350 Astar/Squirrel

Thread Tools
 
Search this Thread
 
Old 29th Mar 2005, 13:30
  #321 (permalink)  
 
Join Date: May 2002
Location: Downeast
Age: 75
Posts: 18,290
Received 516 Likes on 215 Posts
Gray Area,

I think you are missing the point....we are discussing the 350, not the Bell two bladed head. Not withstanding that, there are things that I will not do in various helicopters for various reasons. In any Sikorsky I or Bell helicopter I have flown....the hydraulics always kept up with the control inputs...take from that what you will. In the MBB products....except for some roll coupling...the hydraulics keep up with control inputs. In the Boeing-Vertol products I have flown...the hydraulics keep up with control inputs....it is only on the 350 we hear of this "Jacques Stall" event.

Yes, in the Bell two bladed heads...if you show your butt you can snap the mast off at the top....yes, if you enter negative "g" you can get into mast bumping and snap the head off...or lose control. Yes, in really aggressive maneuvering you can get yourself into a pickle in very high speed, high "g" pullups following a gun-run in a Cobra. Yes, you can over stress the Mast on the Bell 204-212 series if you pull too much power at too high an airspeed....but in all of these events...the hydaulics work with full control authority.

Your question "why would anyone want to operate near Vne at max weight?" Everyone of us who fly these things for a living will do that at some time. As long as the power utilized remains within the set parameters....we usually go for whatever speed we can get on long distance flights....Vne is the limit.....not near Vne....otherwise the Vne would be lower than it is.

There is no denying the fact....the controls should not enter "Jacques Stall" and remove the control of the aircraft away from the pilot. It is poor engineering at best in my humble opinion.
SASless is online now  
Old 29th Mar 2005, 14:12
  #322 (permalink)  
sandy helmet
Guest
 
Posts: n/a
SASless

Applying that line of reasoning then to other aircraft...............
You should be able to be low and slow and heavy in a 206............
You should be able to punch in as much pedal as you want in a 407......................
You should be able to push over a teetering system into low G.........
You should be able to fly into icing conditions.....................
Is fuel REALLY necessary??................................

Point is, every aircraft has its deficiencies, quirks, characteristics etc etc, and granted some are of grave enough concern that they eventually find their way into RFMs as a pilot procedure, or a limitation, while others remain as a known phenomenon to be discussed, taught, trained.

Vortex ring state, or settling with power, doesn't imply a design flaw on a particular helicopter (or does it???)

I do see your point on a system that maybe should perform better, but if it is a known characteristic, isn't the first and obvious fix not pilot technique?? As in not pushing over a teetering head, not putting yourself into LTE, or getting into settling with power?
 
Old 29th Mar 2005, 14:14
  #323 (permalink)  
 
Join Date: Feb 2002
Location: Spain
Posts: 70
Likes: 0
Received 0 Likes on 0 Posts
I've been flying, among others, A stars for 18 years now and have to say that I've experienced jackstall only twice on B models and when I was doing quite an agressive flying. Never had any more on twins (F's and N's) although I have to say that it's been a long time since I don't fly the hard way anymore. So for me it has not been an issue but I've never flown them -25 ºC and it seems that some pilots have encountered that situation in normal flight envelopes , if really so it should be something to take care of.
I fly my AS 355 N with total confidence in flight controls. Just my 2 cents
Buen vuelo
matador is offline  
Old 29th Mar 2005, 14:21
  #324 (permalink)  
 
Join Date: May 2002
Location: Downeast
Age: 75
Posts: 18,290
Received 516 Likes on 215 Posts
Sandy,

In response....in each situation you mentioned...the pilot has the control....not the aircraft. When the controls quit working...the pilot does not have control.

LTE...the aircraft is fully functional...the controls work...might be the tail rotor does not have the ability to cope with the yawing moment but the controls are working. Judgement is the main issue there....keep your nose into the wind...don't let a yaw rate develop.

407 and its tail rotor....seems like the controls work too good there.

Bell Helicopters and their tail rotors are much akin to the "Jacques Stall" issue. Thus you will not get much argument from me about those issues.

Zero "G"....again the controls got you there....judgement is the issue.

Icing....the controls are working....judgement got you into the ice.

Low, slow, and heavy in a 206.....again...judgement got you there.

Fuel....pilot judgement again.

In the 350....with "Jacques Stall"....too many reports of it happening for it to be a simple judgement thing....gets back to engineering and the controls not working all the time.
SASless is online now  
Old 29th Mar 2005, 20:34
  #325 (permalink)  
 
Join Date: Jan 2001
Location: North Queensland, Australia
Posts: 2,980
Received 14 Likes on 7 Posts
I got hydraulic feedback in a Huey once while manoeuvering 'positively' to avoid hitting someone else in a formation, which felt just like the dreaded Jack Stall - unusually fast and large cyclic movement leading to forces through the controls which went away as soon as the severity of the manoeuvre was reduced.
That's the same thing as we're talking about with the Squirrel, isn't it?
Arm out the window is online now  
Old 29th Mar 2005, 20:52
  #326 (permalink)  
 
Join Date: May 2002
Location: Downeast
Age: 75
Posts: 18,290
Received 516 Likes on 215 Posts
For sure hydraulics or pylon mount issues that felt like feedback...or mast bumping....? Used to get hydraulics failure on the Alouette III in severe turbulence....hit a real down draft...all the fluid went to the top of the resevoir....pump cavitated....feedback in the controls...till the down draft was replaced with more normal forces.
SASless is online now  
Old 30th Mar 2005, 22:23
  #327 (permalink)  
 
Join Date: Jul 2004
Location: Durham, NC USA
Posts: 373
Likes: 0
Received 4 Likes on 3 Posts
Jack Stall in the AH-1T

During testing at Patuxent River we experienced a form of Jack Stall in the AH-1T (PT-6 powered AH -1 with a 214 rotor and tail rotor). Even with a 3000PSI hydraulic system the servos were not able to react the flight loads during a symmetrical 3 g pull up. During this maneuver we experienced significant levels of control feed back in pitch. Review of the data also revealed that we exceeded test cards imposed limit of 3 g's. I do not believe that the weak hydraulic system is actually capable of protecting the airframe. Limitations do that.
Jack Carson is offline  
Old 4th Apr 2005, 14:00
  #328 (permalink)  
 
Join Date: Dec 2004
Location: nappyville
Posts: 42
Received 0 Likes on 0 Posts
AS350D info

Can someone help me with the specs of the AS350D and its differences compared to the B series?

Thanks

NB
Nev Bartos is offline  
Old 4th Apr 2005, 14:44
  #329 (permalink)  
 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 72
Posts: 4,154
Likes: 0
Received 29 Likes on 14 Posts
It is powered by a Lycoming engine that had nil respect in the early days, but is now workable. It is not supported by EC

phil
paco is offline  
Old 4th Apr 2005, 15:05
  #330 (permalink)  
 
Join Date: Oct 2003
Location: Canada
Posts: 1,852
Likes: 0
Received 0 Likes on 0 Posts
The "B" series used to be called "Falling Stars". However, paco is right: the newer version of the LTS101 is apparently much better.
See:
http://www.pprune.org/forums/showthr...ghlight=lts101
rotornut is offline  
Old 5th Apr 2005, 00:56
  #331 (permalink)  
 
Join Date: Mar 2003
Location: the hills of halton
Age: 71
Posts: 809
Likes: 0
Received 0 Likes on 0 Posts
SO who knows what the AS350C was ?. One of the early Canadian ships shows c to d to b on its registration.

Mark C-GMEY Serial No 1004
Common Name Aerospatiale Type Certified Model AS 350B
Identification Plate Model AS350C TRANS D TRANS B
Base Of Op. - Country CANADA
Base Of Op. - Province Quebec
Base Of Op. - Location Les Cedres
File Location Dorval Basis for Eligibility for Registration Type Certificate - H83
Type of Registration Commercial
Category Helicopter Weight (Kgs) 1950
Manufacturer Societe Nationale Industrielle Aerospatiale
Year of Manufacture 1979
Country of Manufacture FRANCE


Link to all you need to know about AS350 models

http://www.aviationtoday.com/cgi/rw/...=1003as350.htm
widgeon is offline  
Old 5th Apr 2005, 01:20
  #332 (permalink)  
 
Join Date: Jun 2002
Location: 1 deg south, avoiding Malaria P Falciparium
Posts: 385
Likes: 0
Received 0 Likes on 0 Posts
Rotornut,

I believe the "D" was the falling star, otherwise known as the Death Star.

RB
rotorboy is offline  
Old 5th Apr 2005, 01:48
  #333 (permalink)  
 
Join Date: Apr 2005
Location: far east
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts
I read somewhere recently that a soloy conversion is on the way for the AS-350 using the updated LTS engine with much increased output and twin channel fadec which will give even the B3 a run for its money with MUCH lower DOC's.....would be a great conversion.
With regard to the AS-350 series all the basic airfames are more or less the same not including the engine / airframe interface parts, the t/rotor compensator fitted from the B1 onwards and some minor frames added to the underside of the tranny deck for a/frames modded from B upwards...... The vertical and horizontal stabs are a little different for almost all models. There is a fence on the tailboom of the B1 and B2 that must not have achieved a whole lot because it is not to be found on the B3....
OCTANE100 is offline  
Old 5th Apr 2005, 02:16
  #334 (permalink)  
 
Join Date: Sep 2003
Location: Australia
Age: 47
Posts: 728
Likes: 0
Received 0 Likes on 0 Posts
OCTANE100,

I beleive also that Bell will introduce a version of the LTS 101 into the 407 from 2006 thereabouts!..should be interesting.

Here in NSW the National Parks have a 350BA with a C-30 Fitted to it
belly tank is offline  
Old 5th Apr 2005, 02:32
  #335 (permalink)  
 
Join Date: Nov 2004
Location: the great white north
Posts: 299
Likes: 0
Received 0 Likes on 0 Posts
apparently, the b3 doesn't have a strake because it doesn't need it as it has enough tail rotor authority as it is.
Fun Police is offline  
Old 5th Apr 2005, 02:34
  #336 (permalink)  
 
Join Date: Jun 2002
Location: 1 deg south, avoiding Malaria P Falciparium
Posts: 385
Likes: 0
Received 0 Likes on 0 Posts
Soloy (pappilon ownes the soloy/ STC ) does have a STC for the LTS101, they are calling it a B2 101 or someting. They had one at the show this year. Supposedly the 101 is a super eng now. One thing about the 101 in the d model is it burns dirty, turns the tailboom black in a hurry.

The 101 DOC is a fair bit lower than the french eng.

rb
rotorboy is offline  
Old 5th Apr 2005, 04:46
  #337 (permalink)  
 
Join Date: Jul 2002
Location: Texas
Posts: 512
Likes: 0
Received 0 Likes on 0 Posts
Someone (the name escapes me, but was located in Broussard, LA) had an STC for a conversion of the D model to an Allison C28 or C30 engine. I can't remember if there was a model change or not. It never became very popular.

When I transitioned into the AS350D I thought it was heaven at first - a heater, 3.5 hours fuel, fast, comfortable, roomy, and very responsive. The B206 paled in comparison. And it was a nice ride as long as everything worked the way it was supposed to. When things started to go wrong, it could be a handful. I still recall doing a postflight and wondering where the water on the engine deck had come from. Turned out to be kerosene, and the fuel manifold that was mounted behind the combustion chamber, in a circle around it, had sprung a leak, spraying fuel directly onto the combustion chamber. The good news was that the leak was large enough that the amount of kerosene being sprayed provided cooling, and was too heavy to ignite.
GLSNightPilot is offline  
Old 5th Apr 2005, 06:28
  #338 (permalink)  
 
Join Date: Jan 2003
Location: TI
Posts: 217
Likes: 0
Received 0 Likes on 0 Posts
Flavours of the 350

AS350C was the first with a LTS 101 600A and preceded the B model in being type certified.

AS 350D came after the C with LTS 101 600A2.

AS 350D1 is the same as the D with a LOWER MTOW.

AS350B came along with Arriel 1B engine.

All of the above have "Blue" MR Blades.

AS350BA is a "B" with 355 "Grey" blades and 355 TR blades and a few mods to the transmission deck.

AS350B1 is like a BA except with a Arriel 1D engine and TR compensator and boom strake.

AS350B2 is as above with a Arriel 1D1 and different tailpipe.

AS350B3 is basically a B2 with an Arriel 2 engine (FADEC) VEMD and NO boom strake as it has the TR off a 355N Model.

EC130B4 is EC120 at the front, B3 in the middle except with Dual hydraulics and EC135 in the tail although a mirror image due to direction of rotation.

There is/was a Soloy conversion to install a 250C30. Ones I have seen have some probelms with exhaust re-ingestion and if you look at the installation it is very "draggy" compared to the Lyco or TM.

There is a "Super D" with an LTS 101 750 and effectively B2 running gear.

Some people who have stuck by the Lyco love them. Low fuel burn and the engine can be operated "on condition". You can do a lot on the Lyco yourself. TM are very reluctant to let people outside their organisation mess with their engines.

And there is an odd one out there - AS350BB UK Military training aircraft (HT1) which I think is a BA with a 1D1 in it.
Giovanni Cento Nove is offline  
Old 5th Apr 2005, 07:56
  #339 (permalink)  
 
Join Date: Dec 2004
Location: nappyville
Posts: 42
Received 0 Likes on 0 Posts
Does the LTS 101 600A2 have all the problems soughted out or is one to stay away from and stick with the Arriel donk ?

I am looking at a machine with an approx 2500 hrs TSN.

Thanks

NB
Nev Bartos is offline  
Old 5th Apr 2005, 16:21
  #340 (permalink)  
 
Join Date: Jan 2003
Location: TI
Posts: 217
Likes: 0
Received 0 Likes on 0 Posts
Judging by the terminology you are using - look to the East of you. There are a few operating and there is a bit of experience there.

Talk to someone at Airwork (NZ) they look after 350D's and BK's with similar engine.

One O Wonderful's have some form in NZ. The Cresco Ag machine had the LTP although now carries a PT6.
Giovanni Cento Nove is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.