TOD

Well we have triple ADC and triple AHRS but after that the similarity ends! I guess weight and space is an issue for RW. Actually there is an interesting question...You say you have triple ADC and interial ref but are they triple identical systems? We have two identical AHRS systems and one different. So far we have had no single AHRS failures but a couple of double ones where the two identical systems decided to crash at the same time (software issue associated with magnetic anomaly on a particular platform). So I am glad that we don't have 3 identical systems!

Hip - yeah, why not! Which of the colonies are you in these days - convict land or cowboy land?

HC

Sounds good Hip, I'm hoping we can all get together! HC I'm PMing you with a little little extract of the Flight Crew Training Manual FYI

TOD

TOD and HC

We will have to make the effort to locate the whole cast, lost are SW KM and CC, you may know where they are but I don't.

HC, I am back in the former, got tired of chewing baccie and wearing a big hat.
3 AHRS huh? Do you have any platform info in the FMS?

So, what happens if you "fiddle" with the course bar and stick your arm out the window at the same time?
Zeb

The problem, of course, is not fiddling somehow the course set, but selecting the wrong one . . . that's it.

Just the position of the platforms. We also have the company routes (HMRs etc). Its the customised part of the database - same contents as for the other fleets with Trimble 2101

HC

Referring to the original question: does the aircraft eventually regain the localiser, once it has departed, or does it remain off course?

HC, is your FMS of FW origin, and if so, is there no opportunity to subscribe to a larger database? We use the Universal UNS-1E, in the S-92, with a worldwide airport database, including all SIDS, STARS and Approaches (including the transitions and Missed Approaches). It even allows us to fly the fully Managed LNAV/VNAV NPA approaches TOD mentions, allowing CDFA stabilised procedures, rather than 'dive and drive'.

TOD, our FMS sets the course too, but only for NPAs, not for ILS.

The S-92 coupled ILS function seems carefully programmed to closely resemble a badly hand flown ILS, with even a 6 kt crosswind capable of generating in excess of half scale localiser deflection close to minima (flashing yellow diamond: just what you want in IMC)! :ugh: Some changes required before looking at Cat II I would say!

212 - The FMS is a CMA3000 made by Canadian Marconi, though later aircraft will have the CMA9000 which is a later version of the same thing.

From their web page "The CMA-3000 is a compact flight management / radio management system well suited for fixed and rotary wing aircraft requiring performance, but having space and weight constraints." whatever that means!

We supposedly have a worldwide (European at least) database and it seems to have everything in it for all airfields except those north of Edinburgh. Duh! Of course the contents of the database are not the fault of CMC but there seem to be very few providers of customised databases in the vicinity and our current provider is unresponsive.

You say your UNS can do NPA approaches - does it have TSO 145 GPS receiver? If only TSO 129 I don't think you would be allowed to do NPA approaches with gps as the sole aid in most of the world (except USA).

225 is amazing in that area - one night I was flying training ILSs into EGPD RW16 with wind at 2000' 75kts at 60 deg right of final approach track (coming over the hills) with ATC man giving real-time surface wind callouts as they like to do. It went like this "....50 kts.....5 kts....50 kts..." etc - kind of gusty! We had to slow to 130 just to reduce turbulence so that we could see the instruments and avoid physical damage with parts of the cockpit, but ILS needles remained dead centre all the way. Afterwards Eurocopter man said they had decided to always paint the needles dead centre regardless, but I think he was joking!

Afterwards ATC man was heard to pass comment that whilst the 737s had been exploring the ILS envelope, the 225 came in right down the middle (they monitor with radar)

That's what an inertial autopilot does for you and personally I would not trade that for a gadget that sets the final approach track for me!

HC

S92
 

Very surprised about the poor performance with the S92 on the ILS. Like the EC225, the EC155 is very accurate even in challanging cross winds.

212man
yes, unfortunately it remains off course !

Hi Sax412
Slightly off the subject but I am interested to hear your opinions on the Grand in turbulence with regard to the autopilot being able to handle it. Like you I have transitioned from the power to the grand.
Flying along at 145/55 is great until you find that a small level of turbulence will pitch and role the machine to VNE unless you intervene.
On the power I find that the machine would hold heading and altitude but on the Grand it’s up and down 100/150 feet.

Lenticular, not as surprised as me! As you say, the 155 is on rails come rain or shine.

OEI and Still Flying . . .

. . . I haven't experienced such a kind of problem so far but the Grand is, generally speaking, a little bit more sensitive though.

HC,
"You say your UNS can do NPA approaches - does it have TSO 145 GPS receiver? If only TSO 129 I don't think you would be allowed to do NPA approaches with gps as the sole aid in most of the world (except USA)."

No, it's TSO-129, but the point is that you don't use it as the sole aid: you MUST have the raw data available to monitor (see photos of the P-ILS in the other S-92) thread.

With the Garmin 530 installations I've seen on 412 and 76, you just keep programing whatever approach you want (NDB, VOR, ILS, RNAV) on the GPS and let it drive the track bar on the HSI to wherever it wants (does a better job of the correct inbound than the pilot). It also tunes the correct ILS frequency into the Nav receiver. Once on final for an ILS you simply switch the OBS source to VOR/LOC and leave the trackbar where it is. The old 530 is only TSO 129 A1, but you still fly RNAV only approaches with it as long as they exist in the database.

Looked at the S92 panel pictures but can't figure out what is meant by "raw data to monitor". You mean like a wet compass?

I see Malaysia and Brunei are a little behind the RNAV curve, but you could certainly file IFR to Singapore (Changi) and fly the RNAV approach with only the Garmin. My take on the TSO 145/6a is that in the US you can file destination and alternate using a single GPS receiver that meets that TSO, but with the older non-WAAS units under 129, either destination or alternate needs at least one ground-based navaid approach.

Nothing but pilot stubborness to keep you from flying any NPA in the GPS database coupled to the FMS, and simply monitoring the underlying navaids. Fixed-wing guys been doing it for years, and I've noticed the helicopter side catching on now too.

Anybody in the GOM flying GPS Approaches with the 92? I doubt if the North Sea or SE Asia is, except as overlays.

Malabo

212 thanks, that clarifies it.

malabo - what is meant by "must have the raw data available" is exactly what you mean by "monitoring the underlying navaids.

I think we are on the same wavelength, just using different words!

I know that Australia now allows NPA approaches with gps as the sole aid but it must be tso145/6

HC

Malabo, it's as HC says: Raw Data is the information coming straight from the ground based navaid, through the onboard receiver, and appearing on your display, either using the bearing pointers or CDI. It would exclude Flight Director processed information, even if the FD was coupled to a ground navaid.

TSO-145 also allows LPV (Localiser Precision, Vertical guidance) approaches, as well as being sole aid. Having said that, despite only being TSO-129'd, the UNS-1 uses angular scaling inside the final approach (rather than fixed distance scaling) fix when used for an NPA: hence the expression 'Pseudo-ILS' that Sikorsky use.

OEI, please check your PM. :)

HC
To fly GPS NPA in Australia only requires that the box be TSO 129.

Bomber, I guess you are sort of right but I did say "gps as the sole aid" - Oz AIP Gen section 1.5 para 8.5.5.4, item 4 in the requirements list for NPA says

"If a TSO-C129 or a C129a receiver is used, an alternative instrument approach utilising ground based navigation aids must be available"

In other words, whilst it has to be available, it doesn't say it has to be monitored. Perhaps it says that somewhere else, but then again maybe not! I would have thought it was good airmanship to monitor the ground-based navaids anyway.

And of course item 3 says that you cannot use the GPS approach to satisfy the requirements for an alternate unless you have 145/6

HC