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Wrong performance code for 777?


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Guess it will depend on your approach speed Patrick affected amongst others by your landing weight:

APPROACH CATEGORY
Catagory A = Speed less than 91 knots
Catagory B = Speed >= 91 and less than 121 knots
Catagory C = Speed >= 121 and less than 141 knots
Catagory D = Speed >= 141 and less than 166 knots
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I recall a similar topic regarding PMDG's NGX over at Avsim, again the 738 could be either class C or D. PFPX has it as a class 'C', EuroControl a 'D'

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Hello,

skybrary says that the 777 has the performance code C but PFPX says D? Which one is correct?

And could you specify which 777 model you mean?

Some are C and some D, depending on the model you fly.

The ICAO code 772 stands for the 777-200ER and not the 777-200LR which PMDG moddeled ;)

The 777 Freighter and -300 and -300ER are all D aircraft.

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In this case it's a 77L (also category "C"). I'm confused, first (years ago) I thought the category is based on VREF than more and more people said that the category is fix and now?? Is it fixed or not?

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He may be talking about category withing fleet type. We have B777 - A, B and C.

B-category is the base model. A- has lower weights/performance and C - is a bit bigger one. Also cat A has different engine type with reduced trust. These is nothing to do with categories A, B, C and D listed above, those are for approach speed.

Thx

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He may be talking about category withing fleet type. We have B777 - A, B and C.

B-category is the base model. A- has lower weights/performance and C - is a bit bigger one. Also cat A has different engine type with reduced trust. These is nothing to do with categories A, B, C and D listed above, those are for approach speed.

Thx

The 'performance' category Patrick refers to forms part of the ATC flightplan submission, would the 'fleet type' be submitted?

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Performance category is based on VREF at MLW(!), not by your corrent VREF.

777-200 and -200ER are 138-140Kt -> category "C"

777-200LR and 777F are 149-150Kt -> category "D"

777-300 and -300ER are 156-160Kt -> category "D"

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skybrary says that the 777 has the performance code C but PFPX says D? Which one is correct?

Assuming that we are talking about the same aicraft type, both could be true. Let's see why....

ICAO Doc8168 PANS OPS Vol.1 provides guidance on how to define an aircraft's category and states that:"The criterion taken into consideration [..] is the indicated airspeed at threshold (Vat), which is equal to the stall speed Vso multiplied by 1.3, or stall speed Vs1g multiplied by 1.23 in the landing configuration at the maximum CERTIFICATED landing mass. If both Vso and Vs1g are available, the higher resulting Vat shall be applied".

Once a category for a specific airplane has been identified, it "[..] shall be a permanent value and thus independent of changing day-to-day operations".

For this reason, similar aircraft types could stay in a different categories by changing:

  • Landing configuration;
  • Maximum certificated landing mass.
1. Landing configuration

"The landing configuration that is to be taken into consideration shall be defined by the operator or by the aeroplane manufacturer".

2. Maximum certificated landing mass

"An operator may impose a permanent lower landing mass, and use of this mass for determining Vat if approved by the State of the Operator".

Under FAA things are a little bit different...AIM (Aeronautical Information Manual) states that approach categories are:"based on a speed of VREF, if specified, or if VREF is not specified, 1.3 VSO at the maximum certified landing weight. VREF, VSO, and the maximum certified landing weight are those values as established for the aircraft by the certification authority of the country of registry.

A pilot must use the minima corresponding to the category determined during certification or higher. [..]. If it is necessary to operate a speed in excess of the upper limit of the speed range for an aircraft's category, the minimums for the higher category must be used".

So in order to get the right category you should be looking for the operator/airplane manual or simply stick to the guidance provided by Boeing on the FCTM section 5.3 under FAA rules (if you own the PMDG they have provided a copy inside the installer).

2ccsccp.jpg

Last but not least....let me add something about when to add PER/ ....ICAO Doc4444 PANS ATM, Appendix 2 provides guidance on how to file a flight plan and about the use of PER/ it says:"if [..] prescribed by the appropriate ATS authority".

Even Eurocontrol's IFPS User Manual states that it "[..] shall be used [..] whenever that information is necessary (if required by an ATS authority)".

So basically keep it out of your flight plan unless required (check ICAO Doc7030 or local AIP) or deemed important to provide.

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US carriers dont file PER/

(at least the ones who'se ATC plans I've seen, and thats most of them)

Thanks Doug, I just noticed PFPX submits the PER/ as part of it's ATC submission hence the comment above.

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