I have this flight plan, from Cleveland (KCLE) to Pittsburgh (KPIT). The full plan is this:

KPIT ACO DEFOE ZUTIV CUTTA KPIT

 

I fly the PMDG 737NGX, and turn radio control over to the copilot. RC and the FMC in the 737 show the same exact route. All goes well until I approach ZUTIV. RC instructs us to contact approach control on 124.15. I look and see that the radio has been set to this frequency. BUT then there is no more communication from RC, it just stops.

 

I have learned that IF I take radio control back from the copilot, I see a line item in RC that shows I can contact CENTER on 134.90. They do come back to me again but soon tell me to contact approach on 121.55. About this time it really stops working correctly. I guess I want to know WHY the radio communications STOP after the radio gets set to 124.15.

 

Is this a data base error? I don't think RC gets updated from NAVIGRAPH? Perhaps its data base is not current?

Any ideas? This failure is solid, not intermittent.

Thanks,

Jim

RC has a fixed comm database that is not extracted from scenery or an external database.

 

When the co-pilot has the comms it is easy to miss something. In addition the lack of an acknowledge can stall RC. Did you get to an assigned altitude in feet or flight level?

 

Since this is a repeatable error, set up a short flight with the NGX and start a log before you press the start button in RC. Details are posted in the pinned topic at the forum head.

 

Is this only the NGX giving you this problem?

Today I sent a LOG file in for examination. I have tried three different planes, all with same failure as reported. I am flying IFR. and am at cruising alt. when instructed to contact Approach control. The COM radios get set to correct freq. but then no more communications take place.

Thanks,

jim

Could someone else fly this exact route, and report back if they see the problem. The total distance is only about 100 miles, so flying time is short.

Thanks,

Jim

I put your route into FSBuild. It is 57 nm each way. I used a cruise of 20,000 feet (FL200) planned for a B738 which gave me almost a parabolic vertical profile. You are mostly in the the low center strata.

 

 

 

As you can see by the time for each segment it is pretty busy.

 

I won't have time to fly this in a 738 for a few days but when jd can he'll look at the log. I am not sure if a short loop like this can cause a problem with RC and you also have almost a 180 at ACO VOR. You did not hear any complaints from ATC so that turn must have passed muster with in the 5 mile radius of ACO.

 

 

 

The COMS list does not show a 121.55 for KPIT approach. It looks like you are directed to a different airport.

Hello Ronzie,

 

The RC works correctly, until I approach way point ZUTIV. They instruct me (co-pilot) to contact approach on 124.15. Then the problem starts. I am given the other frequency only if I taker radio control back and try to continue on. So, the real problem is the first breakdown in communications when instructed to contact approach on 124.15.

I have flown three different planes, all fail the same exact way. Two of the three were prop planes.

Thanks for your help.

Jim

The frequency database in version 4 is fixed. Rc only uses the runway information (r5 converted to r4) extracted from your scenery and extrapolates a4 (airport calculated center from runway positions. RC does not use Navigraph updates. Waypoint coordinates are pulled in from the flightplan.

 

ZUTIV is 34 nm out from KPIT so timing looks correct. You already met your crossing restriction at 40 nm out or you would have received delay vectors. In the RC window status area, Did ZUTIV sequence off the list? If you had vectors before ZUTA then that would not matter but you never got to approach yet. If ZUTA was in the status list and did not scroll off that might have stalled RC.

 

Was there an alternate airport in your .pln?

 

Did you hear the copilot ack the command to contact approach?

 

Now you have the NGX so the copilot is not flying the aircraft, correct? Even if compatible the RC copilot returns control of the aircraft to the pilot upon reaching approach.

 

Just to verify all waypoints used for navigating the aircraft are in sync with the .pln sent to RC, correct?

 

Were you descending to an assigned altitude when told to contact approach?

 

I also need to know what cruise altitude you used.

 

Are you using a default KPIT or an add-on.

 

ai patterns have first priority when RC selects a runway. That occurs at 40 nm out. In the FS9 default, all runways except 14 have an ILS/LOC. If ai were using the 10's or the winds dictated those the your path was near a straight in. Without RC it would not use as priority 14 as navaid runways take priority. That applies to ai as well. If winds were near westerly than the 28s or 32 might be assigned and you would have received a downwind then base entry.

 

We have had a few reports of problems with short straight in approaches. I believe altitudes were involved.

 

Do you recall what winds were dominant?

 

Did you import the .pln file into your FMC?

 

There are a lot of variables here.

 

I'll call jd's attention to this.

Hello Ron,

 

The flight plan was obtained by looking at Flight Aware. I built this IFR flight plan using those way points. My cruising alt is 11,000. I am 7 miles from way point ZUTIV when RC tells the co pilot to contact approach on 124.15. The Co pilot then responds "approach on 124.15". Then there are NO more communications from RC. Both RC and the 737 FMC LEGS page show I have not reached way point ZUTIV. The flight continues at 11,000 feet and passes over ZUTIV. Both the FMC and RC status advance to the next check point CUTTA. I over fly CUTTA at 11,000 feet. Now RC status shows next point as KPIT and the FMC shows RW28 (I did NOT select the ILS runway that was given in ATIS) as the program has already failed me. The plane continues at 11,00 and pass over KPIT. At no time was I given any instructions to start down. The failure is related to approach control not talking to me after the co pilot responds to 124.15 and the comm radio is set to 124.15. Still no response from approach controller. Please note that I have used RC for years now, and this is the only flight plan that fails for me. All others work correctly. Is it possible you could fly this exact plan and see what happens after approach control instructs you to go to 124.15?

Thanks,

Jim