I took advantage of an ORBx offer of 200 Orbs for ENNO Notodden Airport this evening. I set up my usual quick circuit (departing runway 12), but I had to be careful because of the mountains interfering with a direct approach to the runway. I noted that there is an RNAV approach available for runway 12, and the charts indicate that this follows a valley until visual contact with the airport can be obtained. However, when I selected the RNAV 12 approach in the PMDG 737-600 FMC, it displayed this as a straight in approach. I decided to check it out to see what would happen, and sure enough I turned onto final approach with a mountain directly in front of me. I could just see the airport over the top of this mountain, but clearly it was not a safe approach.

I switched to the LOC 12 approach for my next test flight, and this took me nicely down the valley until I could see the airport in the distance. I then disengaged the autopilot, and conducted a manual landing approach with a slight turn to the right to line up. Not a problem, and I made a smooth landing.

My question is......why did the RNAV 12 approach not take me down that same valley? A straight in approach is hopeless in that location. It seems to me that the RNAV 12 approach at this airport (at least, the one that is in my 737 navigational database) must be faulty. Has anyone else tried this approach at this airport?

It is probably be a issue with the PMDG navdata coding. Current nav charts have the LOC12 APP and the RNP12 approaches displaying pretty much the same. Both are straight in. There is only a 2 degree course difference between the two.  A slightly steeper descent angle of 3.9 instead of 3.0 degrees for both approaches.

I have the correct charts now, and they show the RNAV and LOC approaches to runway 12 offset by 12 degrees to the right, so the RNAV approach in the PMDG 737-600 navigational database is seriously in error. I was looking at a visual approach to this runway at first (which follows the valley).

Edited February 7, 20242 yr by Christopher Low

28 minutes ago, Christopher Low said:

I have the correct charts now, and they show the RNAV and LOC approaches to runway 12 offset by 12 degrees to the right, so the RNAV approach in the PMDG 737-600 navigational database is seriously in error. I was looking at a visual approach to this runway at first (which follows the valley).

Did you update your PMDG navdata?  I think navigraph has separate data for that aircraft.  Looks like a standard T RNAV approach with lnav mins.  The FMS should have been able to do it with ease.

I've not touched my B737 in ages I'll fly it now and see if it works with latest navigraph data

Edited February 7, 20242 yr by ryanbatc

For that approach you need to use the default TBM or the Longitude with the G3000.

24 minutes ago, fsiscool said:

For that approach you need to use the default TBM or the Longitude with the G3000.

You shouldn't need to.  This is not an RNP-AR approach... just a standard what would be RNAV (GPS) equivalent as used in the USA.  EDIT:  Unless you mean by runway length then yes haha, I agree with you.  3675 is far too short for a 737.  Takeoff with displaced threshold is doable though.

Anyway @Christopher Low - everything looks fine on my end....  don't forget to update your navigraph for the PMDG lineup

ENNO_RNP12 by Ryan Butterworth, on Flickr

Beautiful area by the way!

enno2 by Ryan Butterworth, on Flickr

Edited February 7, 20242 yr by ryanbatc

oh by the time i set up a quick/dirty flight and try it, replies have been added so my input not needed, but since i prepared the screenshot i will post it anyway 😁, and yup, same as Ryan here, the pmdg flies the RNP12 approach perfectly, was at 4100ft at NO421 and 1860ft 2.5nm before NO420 (with default scenery and navigraph database, haven't tried default MSFS navdata).

 

Edited February 7, 20242 yr by Bad_T

I am using the navigational database that comes with the PMDG 737-600, as I do not have a subscription to Navigraph. However, since the FMS provides the option of an RNAV 12 approach, I would have thought that it would be correct? I will try it again, but it was taking me directly over the mountain in a straight line to the airport when I tried it last night (as opposed to that 12 degree offset).

For the record, I have also had a problem with the RNAV 02 approach @ EGHI Southampton (a problem that was also evident in P3Dv4).

As for the runway length, I am using the full extent of 1751 metres with my 737-600, although I departed and landed at the airport last night within both thresholds.

Edited February 8, 20242 yr by Christopher Low

5 hours ago, Christopher Low said:

I am using the navigational database that comes with the PMDG 737-600, as I do not have a subscription to Navigraph. However, since the FMS provides the option of an RNAV 12 approach, I would have thought that it would be correct?

How can it be? You are flying an approach with I don't know how many years old data in the FMS and at the same time expecting it to look like in your current chart?

I did not think that the navigational data in the MSFS version of the PMDG 737-600 would be that old?

Not very realistic to want to land in Notodden in 737. Only GA.

59 minutes ago, Christopher Low said:

I did not think that the navigational data in the MSFS version of the PMDG 737-600 would be that old?

I'm not sure but the magnetic variation may have changed a lot in that area.

Are you certain that what you're seeing is wrong?  My approach basically went through the valley and lead me almost straight in to the runway (12 degrees off per the chart).

You have to make the vertical constraints too.  I didn't run into any mountains.

Also, I'm not 100% certain in Europe, but in the USA you cannot use the displaced threshold for landing, only takeoff.

You could try that approach in the default TBM like that other guy suggested.

54 minutes ago, guibru said:

Not very realistic to want to land in Notodden in 737. Only GA.

That is the beauty of a flight simulator. I do not have to abide by real world restrictions.

2 hours ago, Christopher Low said:

I did not think that the navigational data in the MSFS version of the PMDG 737-600 would be that old?

I wouldn't be suprised if it was from 2010... they basically take for granted that people buying study level addons have a Navigraph subscription.

35 minutes ago, Fiorentoni said:

I wouldn't be suprised if it was from 2010... they basically take for granted that people buying study level addons have a Navigraph subscription.

It's AIRAC cycle 2204, so from 2022.

It has always struck me as a bit odd that "they" (PMDG?) don't allow the user to choose the stock navdata as an option.

It has regular(ish) AIRAC updates, and while it may be less complete than the Navigraph database, it's not as horrible as some people think.

As a good and relevant example, the ENNO RNP 12 approach is spot on in the stock data.