OnCourse Software

Aviator68 wrote: *

Sun Nov 20, 2022 5:26 pm

Is it possible to correct the parameters of descent path in PF3 to have a less sloping descent profile?

Yes, it is - this is from the FAQ section of the manual:
Q: The approach to my destination was rubbish. I was far too high when cleared for the approach!
A: Adjust your flight plan descent profile in PF3.

This can be done by setting the appropriate values when you select a flight plan - here's an example that I have set-up for a 737-800: PF3 will then use these values to work out the TOC and TOD positions.

I hope this helps,
Martin

Hi,
I will try.

Thank you very much Dan77 and Pointy56

Reagrds
Franco Lorenzini

Hello,

what I have been interested in for a long time:
What is the effect of the parameter 'Select Airport Type'?
What does it change ?

Maybe someone can expand my knowledge
regards
ggerolamo

ggerolamo wrote: *

Fri Nov 25, 2022 10:54 am

What is the effect of the parameter 'Select Airport Type'?
What does it change ?

I think that it affects which airfields PF3 will use as alternates as the flight progresses.
I know that PF3 allocates one against each waypoint, I believe that these are used if you declare an emergency.
(It wouldn't be sensible to direct a large jet to an airfield with short runways!)
I'm sure that Dave will give the definitive answer when he is able to.

Also, going forward please start a new topic in the forum for a separate question like this one.
It doesn't really relate to this topic and may be of more general interest - thank you.

Cheers,
Martin

Thanks for the info !
The explanation with the emergency airports sounds very plausible....

regards
ggerolamo

Hi,
I flew again with new flight path descent profile, deleted the point too close and deleted the STAR path, checked the STAR box: route EBCI-GMMX.
The PF3 has cleared me to descent before the TDP and for next steps but then, for some reason I don't uderstand, it has again waited to clearance me to descent. When it has cleared me I was over the correct path FMC suggest me so I had to set the airbrake and insert an hold path to let me landing with correct altitude, speed and landing configuration.

Please, could you help me again?

Best Regards
Franco Lorenzini

Well there's a couple of things that need mentioning here.

Firstly, your last waypoint is only 13 miles from your destination, which is far too close.

Next, you were being stepped down quite nicely to the configured altitude of FL 190, prior to reaching MABAP. But then, when you were still 20 miles from MABAP you request a new cruise altitude of FL 190. Why did you do that. Had you not done that then your descent would have continued. But having said that, with an altitude of 7000 at RAMIM, with only 13 miles to the airport, you would have had problems making the approach.

So, a better flight flin with you last waypoint maybe 25 miles from the airport and then once you start your descent DON'T ask ATC to 'Maintain you current altitude' (hotkeys H and L on their own mean 'maintain current altitude') and things should be much better

Hi ,
I flew LIMC-LICJ twice following your suggestions. I deleted the STAR path in PF3 flight plan, checking the STAR box and deleting too close point. Set the descent profile with 1000 ft/min
Twice the beaheviours was the same. Arriving about 40 nm before TOD the PF3 cleared me to descend to FL270, correct, and then no more instruction.
After few minutes left TOD and when the descend path suggested by the PMDG B738 FMC showed me was lower then 7000 feet I asked PF3 to clearance low altitude. Then with set airbreak could arrive to approch control and I followed its instruction.
But for me it is not yet correct.

the same question... what am I still wrong?

Thank you indeed and you patience
Franco Lorenzini

Hi,

This is a bit complicated because your original flight plan included a STAR, so the waypoint altitudes need to be adjusted. You removed all waypoints after GIANO, which is about 52 miles from the destination airport. I would include NALUV in your flight plan, so NALUV will be your last waypoint. This is about 24 miles from the airport (see diagram). At a distance of 24 miles I'd suggest an altitude of about 8000 ft, so adjust the altitude for NALUV to 8000 on the waypoint page. The previous waypoint, GIANO, is about 30 miles before NALUV, so I would adjust the altitude for GIANO to about 16000. If you want different altitudes at NALUV and GIANO, enter the desired altitudes on the waypoint page.

When you cross PEPIX, PF3 will probably give you an instruction to descend 'when ready' so you do not need to begin your descent right away. You should be at 8000 (or whatever you entered on the waypoint page) when you reach NALUV and you will be cleared to descend to 3000 and complete the approach at pilot's discretion (if you have the STAR box checked, as you currently do).

Aviator68 wrote: *

Wed Dec 28, 2022 1:23 pm

Arriving about 40 nm before TOD the PF3 cleared me to descend to FL270, correct, and then no more instruction.

I forgot to mention you DID receive a further descent instruction. When you reached GIANO you were cleared to descend to 3000:

Quote:

28/12/2022 11:44:00: 550 - Transcript: 'Ryanair 511 at Golf India Alpha November Oscar Descend and maintain 3 thousand on 1030 Cleared to final for Sierra Tango Approach runway 25 when ready Contact Tower on 119.05 when established. '

28/12/2022 11:44:20: 760 - Transcript: 'Out of Flight Level 200 for 3 thousand at Golf India Alpha November Oscar until established on the ILS runway 25 Tower on 119.05 when established. Ryanair 511 '

So it will work with GIANO as your last waypoint, but I would set it up as I did above.