AS365
 

Just one quick question. What is that tiny T-shaped thing on top of the rotor head? I don't see it on any other dauphin pictures just on the Coast guard ones.
Just wonderin' :confused:

The USCG Dolphins have standard pitot tubes under the chin and also have this small mast ontop of the rotorhead. This is the Air Data Sensor which is largly outside of the aerodynamic effects of the aircraft during flight and so gives the best indication of wind speed and direction. This data is fed to the autopilot for flight and hovering.

The low airspeed sensor is driven around by a small motor, and it gives very accurate information when the helicopter is below 40 KIAS. It gives side and rear wind, and for a helicopter that hovers over the water in the middle of the night, is nearly essential.. .Every helicopter that flies IFR, and probably every other helicopter should have such a system, but we don't because we've never had them before, so we think we don't need them.. .Bit of a pet peeve of mine - I used it to very good effect on the HH-65 when I was instructing at the Naval Test Pilot School to show hover performance. . .Since it calculates the side and rear wind components and feeds them in to the navigation computer, it gives very accurate wind calculations.

Alright, thats pretty cool, thanks for clearing that up guys.

How come it doesn't get affected by the induced flow through the rotor? Or is it factored for that?. . <img border="0" title="" alt="[Confused]" src="confused.gif" />

The Apache has a similar system mounted above the rotorhead. It is used to compute wind direction in order to correct for the basllistics of the 30mm Chain Gun and the missiles.

The low airspeed system is calibrated (or perhaps characterized would be a better term) to account for the inflow effects. . .The way this characterization would be done is to fly the helicopter at different weights, in and out of ground effect using a pace vehicle to obtain exact airspeeds. This data is then fed into the computer to compare with what it saw, and make the system display the correct values of wind.. .It doesn't work particulary well when doing rapid transitions to and from the hover, but it is way better than nothing.. .We have one of these systems on our ex-Canadian Forces Bell 212 (it was a fully instrumented aircraft from the Canadian test center at Cold Lake)and it is very useful.

The Bell AH1-J and the Agusta A-129 had a similar device in that it measured the direction of the airflow around the helicopter as well as the airspeed. It would align itself with the relative wind in relation to the center of the fuselage. In a hover it would align itself with the downflow measuring air velocity. Like the Apache system it was used to correct for wind for the gun and the missiles.. .. .Unlike the Apache system and that used on the HH-65, which were mounted on top of the rotor system this unit was mounted on the right side of the fuselage immediately next to the pilot position.

All the airspeed systems below the rotor, such as those on the side of the Cobra, are at best a bad approximation of the airspeed during low speed cases. The calibrations of those systems is nearly random where it counts, mostly because the downwash contains strings of high speed tip vortex air that is easily at 40 to 60 knots of energy. If that vortex strikes any pressure sensor (a pitot, or a fancy pressure transducer) the results are chaiotic.. .. .The S-76 pitots, and the Sea Hawk's, are located in the nose so that the blade tip vortex sweeps above them at speeds above 30 knots or so. When we developed the S-76 system (I flew one prototype that had 10 pitots -it looked like a B-17!), we had to track the tip vortex pattern as it swept across the nose at 30 knots, across the pilot's door at 50 knots, across the upper doghouse at 80 knots and finally across the transmission/swashplate fairing at 120 knots. Since the FAA airspeed calibration must be accurate down to 30 knots in level flight, we chose the nose position for the type design.. .. .The sensors above the rotor are affected by inflow, but those are relatively predictable, and much smoother than the hash below the rotor. The first airspeed above the rotor was the S-61 bullhorn system, which uses a common pitot, but is quite accurate and reliable down to 30 knots. The rotating systems above the mast are as a class quite accurate, and also read the azimuth of the airspeed, a boon to weapons shooting.. .. .Comanche uses sensors in the blades to read the dynamic pressure continiously. A computer sorts out the phase and rpm effects, and leaves the airspeed data and azimuth as a very accurate result. The blade sensors are used on Comanche because all the other systems contribute too much radar return.

All very interesting chaps, can I digress from the initial query for a moment....how did the USCG come up with the name 'Dolphin'?.....did they not like the manufacturers name? True, the military have always assigned differing names but I wonder if anyone has any idea on this one.

Prob could not pronounce Dauphin correctly so It came out like Dolphin. Ever heard a Texan trying to get their lips around Ecuriel ??. .edited for bad spelling.. . . . <small>[ 14 March 2002, 12:31: Message edited by: widgeon ]</small>

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">Comanche uses sensors in the blades to read the dynamic pressure continiously. A computer sorts out the phase and rpm effects, and leaves the airspeed data and azimuth as a very accurate result. The blade sensors are used on Comanche because all the other systems contribute too much radar return. </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">I had heard about that, very , uh .. Kewl !

Dolphin, Dauphin same thing. The early 365C's had a large Dolphin sticker on the side of the gearbox cowlings with the word Dauphin. I've still got one somewhere. I sent a fax of it to R&W some time back when sombody started burbling on about the origin of the word Dauphin and it's relationship to Dauphin.

Correction that last Dauphin should be Dolphin

Doesn't 'Dauphin' mean 'Prince' in english??. .. .Excuse my year 10 public school education....

Dauphin is the French for Dolphin.. .. .Dauphin was also used as the French term for a Prince.

AS 365
 

Hello again rotorheads,
Is there somebody here who is operating an AS365N or N2 with an HUMS (or IHUMS) retrofit ?
Are you happy with it ?
I am a bit disapointed about the operational reliability of the model my company has decided to buy .... Lot of money for almost nothing but trouble.
I don't think, in these conditions, that the retrofit of a such complex system on a relatively small (and old) helicopter already stuffed with other electronic gadgets is a + to safety and maintenance costs.

I'm a HUMS engineer, and I've dealt with dozens of AS365'S with retrofit HUMS, there should be no problems whatsoever. What sort of trouble are you having??

I dispute your point regarding safety and maintenance, HUMS is not a fail safe early fault detection system, however, and the CAA will back me up on this, it definately IMPROVES safety and reliability, and on a machine with so many single critical load paths, that is justification enough for its existence my friend.

Remember, the fact that a good HUMS will save you a few beans in terms of maintenance costs by allowing better maintenance planning and spares procurement, not to mention helping your direct operating costs through reduced downtime due to in depth fault investigations, or unnecessary assembly changes when a small component is at fault, is a side issue. The name of the HUMS game is safety, when you are flying out to the ship, or the rigs, the one sound you do not want to hear is "Splash".

E-mail me privately if you want more in depth chat regarding your specific problems, happy to help. :ok:

Thank you for your answer Flytest, and believe I completly agree with you about a normal operating HUMS efficiency in improving safety and maintenance costs (i.e enhancing preventive maintenance, permanent monitoring and component life times)
And I believe this system works well when fitted on an helicopter from factory.
The problem seems to come from the retrofit operation itself, and the result, with the HUMS my company has chosen, is rather disapointing compared to the investment. Basically, in the best of cases, we can use it for track and balance of main and tail rotor :ugh:
For obvious reasons I cannot give too many clues here, but I am going to try an email now (I wasn't lucky last time I've tried it here) but I cannot garantee my words will be able to find your mailbox through the "cyberspace".
Sorry, I am nothing else than a miserable pilot

;)

CPT

Am interested to hear specific problems with HUMS, especially retrofit, after all none of us are perfect. That said there are a few of us out here who believe whole - heartedly in the future of such systems, whether they are made in Toulouse, Eastleigh, Fareham or wherever. One of the biggest problems with HUMS is false alerts, when a system detects a "fault" that isn't really a helicopter problem. This can happen from alert thresholds being incorrectly set, faulty sensors or corrupt data files. All I can tell you is that manufacturers, operators and regulatory authorities are aware of this, and are constantly working to reduce false alerts, without compromising the ability to detect real faults... its a fine line :ok:

OK Flytest, this is the last snag we had, just after a few days routine scheduled maintenance operation:we air tested our bird and our HUMS completly failed the symptoms were;
1/ No record at all on the data card (we tried 2 different)
2/ "MDR" light on at all times(normal because of 1)
3/ The red light on on the "IMP"(normal, because of 1 and 2)
4/ No "HUMS" warning light on the caption advisory panel....(not normal, I think)

This came after a slow progressivly degrading situation along with passing weeks, I believe our HUMS just gave up its fight with many thousand greemlins.
I must admit such a sophisticated device requires a very comprehensive training to keep it operating properly, as well as a good deal of experience.

By the way did you get my mail ?

Rgds.:p

CPT

This could be a whole bunch of things, it may be something as simple as your data card not "pre-flighted" properly, however it is likely to be something more.

Without going into too much depth here, if you fly for the company I think you do, then I know the HUMS expertise is lacking there, however, you have a support agreement with the HUMS manufacturers, therefore I suggest you (Or your engineers) raise a problem report and get the guys at the HUMS Support desk on the case, from what you have said they should be able to fix the problem without too much fuss.:ok:

Yes Flytest, you have put the finger on it, the HUMS system set up should go along with a real expertise and an open minded maintenance policy...but this is another story :rolleyes:
It is one of the aspects of a silent revolution our corporation has to chalange, of wich the "jurassic park thinkers" will not survive.
The concern is: how much arm can still they cause untill then ?
.... but here the slope becomes a bit slippery
;)

Glad to have talk to you Flytest.

Costs for AS365 N3 initial training course?
 

Does anybody know how much the initial training course on the AS 365 N3 at Helisim or any other facillity is?

I have a 1996 FSI S76 course list in front of me. In 1996 an initial FSI S-76 initial was $19,225(US) with a sim-check ride.

The 365 is in the same cateory so I'm a quessing it will cost in excess of $20,000. US.

AS365N3 - Any experience?
 

Greetings from sand-side. The customer we work with has ordered 2 AS365N3s which are due for delivery next year. Later this month, the Manager is off to France to complete the deal, hand over the IFF/ELT codes and generally check that all is well. He has asked us to provide him with a list of questions that he should ask Eurocopter, to minimise the risk of any nasty surprises. We have gone through the RFM that Eurocopter have provided, along with what role-equipment information we can find, and have produced a useful list. However, it would be very helpful if any users out in Rotorhead-land could provide us with info/experiences on the AS365N3, particularly regarding introducing it into service. So, if you have any knowledge you're willing to share, would you do it here or by PM please?

Thanks in advance,

Thud

Helmet Fire - Whats Childflight in Sydney got, is that an N2 or an N3.

Dont worry found out it is an N2 at Childflight. However Vic Pol in Melbourne have a couple of N3s there and they were the first ones to be used for Police work in OZ. Will see if I can get a contact number for them.

Cheers

:E

I'd just like to say a public thankyou to those who've contacted us about the N3 - particular gratitude to Our New Zealand Correspondent for his part in arranging most of the comms! We look forward to continuing our acquaintance with the operators we've met online, and to passing-on the acquired knowledge as it builds.

Now, anyone else out there operating EC135T1s at 50 degrees Celsius who'd like to pass on useful tips/ share their worldly wisdom:D :cool: ?

Don't do it!!
 

Get you one of them proper 135s, you know the T2/P2 ones.

We've all been flying as test pilots in the T1 until the real 135 turned up :yuk:

Too late, Bomber, they've had 'em here for 3 years (2B1 engines!). Our job is to make them work in a worthwhile manner...

Thanks for all the test flying, though:ok:

Same problems with the engines as the S76C+ models in hot climates - the engines fail to meet power assurance minima and have to be rejected early. It seems the Arriel 2 series engines don't like hot climates, no matter what type they're installed in and have problems maintaining power margins around 600 hours.

The other problem with the N3 is range. It has the same fuel capacity as the other N models, but fuel consumption is up to 305 kg/hr at 140 kts TAS at lower altitudes.

The twin engine power is excellent and it's good for 'hot and high'. If you're heavy and flying at altitude, don't be surprised if the first limit you reach is the collective top stop, before getting to any engine or transmission limits. You'll still get at least 140 kts TAS though.

etienne,

Thanks for the information; fortunately our (pressure) altitudes aren't going to be particularly high, no jebels or hills in this neck of the Arab/ Persian Gulf. Lack of range MAY not be a problem, as the operational radius for our task is pretty restricted. I hadn't even realised that any other aircraft type operated with Arriel 2s - you live and learn, eh?

AS365 variants
 

Can anyone give me any views on the AS365 as a corporate machine, both from pilot's and pax point of view? What benefits do the N1 and N2 have over the earlier Ns? Particularly interested in speed and range. Rough price guides for a decent acft?

Dauphin endorsement
 

Where can you get an endorsement fro the above type in Australia, including approximate cost please?
Thanks
WLM :D

The operators of these types are (from north to south):

CQ Resq at Mackay
Capricorn Rescue at Rockhampton
Westpac Rescue at Lismore
Child Flight in Sydney; or
Victorian Police

Try any of them and ask for a price. I would assume you would get a wide variety of instructors.



:ok:

Thanks Oogle, will drop them an email
Regards
WLM :D

C-series Dauphin question
 

Hi everyone,

I heard that you can't idle a C-series Dauphin because the vibrations of the tail rotor drive shaft at idle can produce structural fatigue.

Is that right? Does this mean the engines are always running at higher than idle? Can someone explain this?

Regards,

Tickle.

No idea whether it's due to vibration, but the 365C Start and Shut Down procedures don't allow any running at "ground idle". After start, the FFC lever should be "pushed forwards slowly until it contacts the forward stop", and for shut down "Set the FFC in the shut down (fully rearward) position without pausing in the 'idling' detent".

According to my old Flight Manual, anyway: it may have changed!

On the 365 C series, the shut down procedure is now to set one engine on ground idle (30 sec) while the other remains at flight idle. After these 30 sec, you shut the idling engine off and you set the one that was on flight idle to ground idle for another 30 sec.
It is said that the vibration frequency with both engines on ground idle doesn't match with the tail boom metalic structure.
This procedure is the same on AS 365N but different on N2 where you can set both engines at ground idle (30 sec)....The tail boom is made of composites here.

AS365 vriants
 

I have several AS365N2 & N3 in service. Everything is matter of power. All of the AS365 are very fast cruising helicopters, ca 175 knts max, cruise is 150 knts. They all fly very comfortable, ths due to theconstruction of the Main Rotor. Very good helicopter.