Hi.

 

I have a problem with inputting Heathrow Runway 9R Midhurst 3 Juliet into my FMC. All looks good until I input my cruise level into PERF INIT, when the ND shows that I am to fly a 360 degree loop directly over the end of the runway. I have performed the procedures correctly, having set up the INIT REF, Route, DEP/ARR and PERF INIT.

 

I have asked over at Navigraph forum, and the Mod there has the same problem with the NGX, but not with the 777 which uses the same Airac data.

 

I am using:

FSX Steam, Win7 64bit, Airac 1601 and I'm up to 770 hours on NGX

 

Does anyone have an ideas about this, or is having the same problem?

 

Thanks!

 

Rob Padgham

 

 

Loops like that do occur from time to time in SIDs.   The FMC doesn't know that the SID says to make a right turn to intercept R126 LON.  It only knows that it needs to intercept R126 LON from the previous waypoint and it computes what it thinks is the most efficient way to do that.  The pilot flying does know that a right turn is required, having briefed the SID, and as that portion is being hand-flown, will fly the correct path.  I've seen the FMC recalculate the correct path once airborne.

Some SIDs do that in RW, too. I can think of one in Denver where it gives you a "whifferdill."

 

You might be able to simply proceed direct to the first fix or put in a leg intercept to get rid of the 360.

Initially I did not see a problem on the ND (FSX Acceleration/PMDG-600) just entering the SID as a test (yesterday).

 

Then I entered the CRZ alt (today) on Perf INIT .. then I seen the 360 circle.

 

I did not fly it to see if it would actually do a 360 or properly follow the SID.

 

But I have seen the ND paint improperly on other aircraft (LevelD e.g. as I recall) .

 

Ref:

SID MID3J RNW 09R FIX OVERFLY D132B AT OR ABOVE 590 FIX OVERFLY D126D HDG 162
INTERCEPT RADIAL 207 TO FIX D027S
FIX D027S AT OR ABOVE 3000 FIX D027O AT OR ABOVE 4000 FIX D027L AT OR ABOVE 5000 FIX D027H 6000 FIX MID 6000

 

That's great, thanks guys.

 

There's some interesting points here for me to go and look at. I did think of hand flying it, but I knew ATC would be barking at me immediately after take off, so I flew direct to the first waypoint.

It'll be interesting to see if it does adjust itself as Larry suggests. I will try this tomorrow. I'll also have to learn what a leg intercept is! Hopefully something I already know but didn't know it was called that.

Thanks again guys. It's good to know my NGX isn't broken, and it's great to get the support from those more knowledgeable than myself!

 

Rob Padgham

What you might want to try to do is this:

 

Go to your FSX directory, then PMDG, then SIDSTARS. Look up the .txt file for that airport, open it, and have a look at the description of that particular SID. Save the file to something else first, so you can revert it back. If you see an illogical step that is causing the loop, try fixing it.