High cruise alt PFPX on short trips

[SteveW 1,792]

Most flight planning software has a minimum cruise time that is rather short, on the order of two minutes or so.  It's not uncommon to see real-world flight plans that have the TOC and TOD only minutes apart.

 

Yes, I expect a good planner would allow a minimum cruise time preference to be set.

all the best

[FlyBoyMike 38]

I just did a short flight the other night between Bergen (ENGM) and Oslo (ENGM) using PFPX for my flight plan. It did calculate an optimal cruise alt of FL310 which I went with even though my optimum on the FMC was coming up in the FL200's. I was also a bit surprised it came up with such a high alt for a short flight and only left me less than 5 mins cruise time but wasn't really a problem since I did all my descent planning on the way up.

 

I suppose like others have already said PFPX works out the most efficient cruise alt for you if you select that option.

 

I've been flying around Norway on VATSIM a bit this week and find it really nice. Europe generally works well in my time zone as I can do mid morning to afternoon flights based on RW time. There's been a bit of stormy weather around those parts too whereas it's been mostly clear/dry conditions around Aus.

[Dave_YVR 973]

 Keep in mind the differences here between real world structured airspace and what PFPX may plan for on shorter legs. You may find that real world operations are always much lower which in many cases be because of the design of the airspace or procedures.

[Driver170 42]

If you have RC or any other ATC addon they will descend you before you even reach FL300 and get warning errors without reaching your cruise alt.

 

So like again its far too high for fsx use IMHO and i'll be using the FMC OPTM alt from now on.

 

Anyone else agree?

Dave you are right about airspace structure as with Nats uk you're limited to FL145 to FL245 for short flights that i'm doing within the UK and with PFPX giving you an alt of FL300 i know myself I FULLY UNDERSTAND PFPX EVERYONE, so i need to change the cruise alt between these restrictions and thats why i posted on here earlier that what should i do about it? Will i get another cruise alt from real world flight plans or another database?

[Vargveum 53]

 

 

I just did a short flight the other night between Bergen (ENGM) and Oslo (ENGM) using PFPX for my flight plan. It did calculate an optimal cruise alt of FL310 which I went with even though my optimum on the FMC was coming up in the FL200's. I was also a bit surprised it came up with such a high alt for a short flight and only left me less than 5 mins cruise time but wasn't really a problem since I did all my descent planning on the way up.

 

Yeah, that's the way it's done in the real world on these routes  B) Up - down. 

 

 

Dave you are right about airspace structure as with Nats uk you're limited to FL145 to FL245 for short flights that i'm doing within the UK and with PFPX giving you an alt of FL300 i know myself I FULLY UNDERSTAND PFPX EVERYONE, so i need to change the cruise alt between these restrictions and thats why i posted on here earlier that what should i do about it? Will i get another cruise alt from real world flight plans or another database?

 

Exactly, watch the real world flights and see what FL they normally use. All I am saying is that PFPX isn't crazy, but if you know better (ie route restrictions etc) just override PFPX and put in the specific level you want. 

[Driver170 42]

ok will i stick with the alt that PFPX spit out or try a different altitude?

[Vargveum 53]

 

 

ok will i stick with the alt that PFPX spit out or try a different altitude?

 

Totally up to you. PFPX will give you the optimal FL based on fuel economy. That's what it did when it came up with FL300. However, if you want to replicate real world procedures involving FL restrictions, override PFPX and enter your desired FL manually.

 

Personally, I'd follow the realworld procedures. 

[pcubine 143]

 

 

I FULLY UNDERSTAND PFPX EVERYONE

Why are you still asking questions on the PFPX Forum after the time of this post?

[Driver170 42]

Real world procedures is for me for short flights! Now, tell me the best database to get the alt?

Yes i posted it up on PFPX why wouldn't i?

 

 

The questions i'm asking is about using real world procedures instead of the alt PFPX gives you on short flights!

 

I don't know why your bringing this up on avsim and on this topic

[scandinavian13 5,192]

 

 

Real world procedures is for me for short flights! Now, tell me the best database to get the alt?

 

For the United States, you're looking for the PREFROUTES DB.

Here: http://www.fly.faa.gov/rmt/nfdc_preferred_routes_database.jsp

 

Be careful, though.  Since it's FAA-only, they only coded it to use FAA codes (which are similar to IATA in being 3 letters instead of 4).

 

So, KIAD-KJFK is IAD and JFK in the relevant boxes.  This would show you that, in a 737, you max altitude is 17,000 along the route PALEO V44 DONIL V229 PANZE V44 CAMRN.

^ you do not file a STAR on this particular route, btw (the site doesn't tell you that, but I'm just adding from op experience)

[luke11brown 0]

Similarly, to what Kyle just posted, the UK has a "Standard Route Document"

 

http://www.nats-uk.ead-it.com/aip/current/srd/SRDDOC.pdf

 

It lists all the domestic UK routes, including SID, STARs and Altitude Caps.

 

There's also a quick and easy program that interprets it for you!

 

http://www.simsrd.myzen.co.uk/

 

For your route (EGPF-EGGP) the Max FL would be FL240.

 

Hope this helps!

[Driver170 42]

Kyle thanks alot i will look into the link.

 

Already have that luke cheers, but what i'm trying to accomplish is what alt to pick within the altitudes capped in nats ie fl145 to fl245? Prob best to go for the least wind speed and direction?

I'll take a look at that programm too

[jambo50 15]

Vernon, can I ask what the route is that you are using?

 

EDIT: And also, can I ask what is in the 'Init Cruise Alt/FL' box in the aircraft section in PFPX? e.g. OPT, MAX, OPEN ALT, OPEN MAX?

[scandinavian13 5,192]

 

 

Already have that luke cheers, but what i'm trying to accomplish is what alt to pick within the altitudes capped in nats ie fl145 to fl245? Prob best to go for the least wind speed and direction?

 

When you're planning the flight, if you go to the Advanced tab, there should be an option that allows you to force an altitude (above, below, or even a range, I believe), and then a fix on the "other side" that allows you to tell PFPX to resume the OPT alt profile.  If you give it a min/max/both, it will intelligently pick the optimal altitude above the min / under the max / between the min-max, respectively.

[pcubine 143]

I don't know why your bringing this up on avsim and on this topic

 

 

Vernon Howells

You are right. I apologize. I should have done it by PM.