SID/STAR/APPROACH free Database Project

fdd_fr
Posts: 1764
Joined: 03 Jan 2012, 16:02

Re: SID/STAR/APPROACH free Database Project

Post by fdd_fr »

I discovered a problem in a holding pattern of the STAR SEA HELNS 5 of KPDX.

If a holding pattern has a heading "360°" in one of itsleg, the FMC stop to work and the aircraft become crazy.

It is mandatory to write "0°" and not "360°" for a heading in a holding pattern (in STAR or Approach files).

I will check all airport of the actual database to fix if there are some "360°"

And I will add this information in the SID/STAR user manual.

Francois

The320Pilot
Posts: 354
Joined: 29 Jul 2014, 22:47

Re: SID/STAR/APPROACH free Database Project

Post by The320Pilot »

FD, should I write altitude (MSL) or height (AGL) for the Runway waypoint in my IAFs files?
How does the aircraft know which is the MAP if it's coded the same way as the other waypoints?
Is the FD-FMC able to execute missed approaches by itself?

fdd_fr
Posts: 1764
Joined: 03 Jan 2012, 16:02

Re: SID/STAR/APPROACH free Database Project

Post by fdd_fr »

Hi the320pilot

In all SID STAR APPROACH files, all altitudes must be write for all waypoints in feet above MSL.

Ecxept in the approach files, only for the last waypoint of each approach which is the runway threshold ( waypoint type "R" ). The runway threshold is the only waypoint which must have an altitude in feet AGL.
On the approach charts, this altitude is indicated in italic or between brackets.
This is the alone exception, because FD-FMC use this value for the DH or MDA.

About missed approach data, they ard not coded in the data files, but FD-FMC has a basic missed approach procedure. In case of go around just before landing ( you must disconnect A/THR before do that ) , FD-FMC reset approach data and the aircraft return to the IAF to do a new approach.

Francois

The320Pilot
Posts: 354
Joined: 29 Jul 2014, 22:47

Re: SID/STAR/APPROACH free Database Project

Post by The320Pilot »

fdd_fr wrote: In all SID STAR APPROACH files, all altitudes must be write for all waypoints in feet above MSL.

Ecxept in the approach files, only for the last waypoint of each approach which is the runway threshold ( waypoint type "R" ). The runway threshold is the only waypoint which must have an altitude in feet AGL.
On the approach charts, this altitude is indicated in italic or between brackets.
This is the alone exception, because FD-FMC use this value for the DH or MDA
Wait a minute. According to the manual, I should use the DH (AGL) and not the DA (MSL). That's ok. But, because FSX uses a flatten for pretty much every airport, the runway threshold height (AGL) should be 0. That is what I understood.

fdd_fr
Posts: 1764
Joined: 03 Jan 2012, 16:02

Re: SID/STAR/APPROACH free Database Project

Post by fdd_fr »

DH (Decision Height) or DA (MDA Minimum Decision Altitude) are the same thing and are always indicated with the 2 values (MSL and AAL - Above Airport Elevation).

DH is the word used for ILS or LOC approaches
DA or MDA is the word used for RNAV, VOR, NDB or visual approaches.

But in some case, the word DA is used also for ILS approaches. The word has no importance, because the FMC use only the value.

More the approach is a highest precision approach, Less is the value of the DA (or DH). When you have a vertical guidance (ILS) , you can found in the charts the word "LPV" to describe the aircraft category (Localizer performance with vertical guidance). Don't use the LPV value for RNAV appraoches.

But on all charts, you have always the two altitudes indicated. MSL and AAL

The FMC displays the word DH on the PFD for ILS or LOC approahes and it displays the word MDA for all other approaches and the XML code use this value for the lastest autopilot altitude and for unlock the ALT knob.
You must use always the AAL value for the last waypoint of all approaches (this waypoint is always the runway threshold, a waypoint type "R").

samples with charts :

Here is the lower area of the ILS 25R chart of KLAX :
Image
In the red rectangles, this is the values MSL ( 294 feet for the ILS approach and 560 feet for the LOC approach)

But in the Freenav files, you must write the values in the blue rectangles that are AAL :
200 feet for the ILS approach
466 feet for the LOC approach


Now, KLAX, RNAV approach :
Image
For RNAV appraoch, you must use the LNAV (horizontal guidance only) value in feet AAL. Here 475 feet.

The value AAL is always the second value and is always minus than the MSL value (except if the aiport is under the sea level, case of EHAM).

LPV value is the aircraft use in final the ILS, but in freenav files, do not use this value for RNAV approach.

Last exemple with a french chart of LFPG ILS 27R :
Image
Value to write in the Freenav file for the runway threshold :
ILS approach : 200 feet
LOC approach : 370 feet.

As you can see, in many countries, the AAL value is between brackets.

In the most cases :
- ILS approaches have value between 100 and 200 feet
- LOC approaches have value between 200 and 500 feet
- RNAV approaches have value between 400 and 1500 feet
- VOR approaches have value between 500 and 1500 feet.

This is the only exception; In the Freenav airport data files, all the waypoints have their value in feet MSL, except the runway threshold, the last waypoint of each approach.


Other exception, in the header of the SID (file SID_data.csv) , the LNAV value, Thrust reduction altitude value and acceleration altitude value are also in feet AAL (or AGL).

Francois

esg
Posts: 1591
Joined: 01 Jul 2009, 22:03

Re: SID/STAR/APPROACH free Database Project

Post by esg »

I don't know if you're aware, but Eurocontrol's EAD is free to access and has all the European AIPs.

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