A109S GPS APPROACH RFM LIMITATION

[BlenderDriver]

Hello folks ,

I'm transitioning from the S92A to Agusta 109S (grand) and during my IFR type cert. training I found a kind of "weird" limitation on its Flight Manual and That says on Part 1 Sec 1

"AVIONICS LIMITATIONS"

-- GNS430 and GNS530 systems must not be used for GPS approach.

So , I'm very impressed about it , I couldn't figure out why Agusta has limited those two GPS Units for performing GPS based APP even meeting all TSO's requirements ( C129a , Class A1 , terminal , en route and app):ugh:

I need to show the local Regulators that the A/C complies with ICAO PBN requirements but having this manufacture statement it going to be hard.

Does anyone could help me out to understand why is limited ?:rolleyes:


thanks guys

[Art E. Fischler-Reisen]

I believe the 530W (WAAS) is not limited in that way.

It's down to a matter of how accurate the positioning will be for vertical navigation.

[noooby]

From the GNS530 Manual:

"The GNS 530 allows the pilot to fly non-precision and
precision approaches to airports with published instrument
approach procedures."

It goes on to say that all such approaches are stored on a Jeppesen data card. So if the approach you want to use isn't in the Jeppesen database, the GNS530 can't be used to legally fly it.

Not an Agusta restriction, a Regulatory restriction. When the 109S came out (2005) I guess WAAS was still in the future.

[BlenderDriver]

Hi Guys ,

I tried to contact Agusta Support in Italy and they said that A109S is not certified for GPS Approach and only for RNAV 5 can be flown in 109S if you want to comply with PBN regs .
Thats pretty much unacceptable due to the performance of both GPS units for a very simple procedure which is the non precision GPS APP.

Go figure why thats limited in this way.!!!

[noooby]

So what does the aircraft need to meet PBN Regulations?

If it needs WAAS GPS units, then look into the costs associated with doing a mod or STC and go get it certified.

Or, ask Leonardo to do it for you at your cost. They will then issue a Service Bulletin specific to your helicopter.

If and only if they think there is a business case, then they will pay the costs and issue a Service Bulletin that anyone can install.

PM me the details of where you are, which machine and who you contacted and I'll see if I can get a better contact and clearer answer for you.

[duncan_g]

Assuming that the nav indication is displayed on an external CDI or HSI, it may be that the GPS annunciations are not displayed within the primary field of view. Depending on your jurisdiction, a field approval may be available to install the required annunciations and remove the limitation. See FAA AC 20-138D Section 12-11.