Go Around - what did I do wrong?

[Holger]

Hi,

the A300 has become my favourite plane at the moment. Today, I was flying into Nantes Atlantique LFRS, RW21. This RWY has an RNAV approach. During the final phase of this flight, I was turning into Final Approach and I was flying according to the requirements given by Approach Chart. AP was active, I have activated "Land" and "Approach", so that "CAT2" was shown on the PFD.

So, I thought that RNAV would be active - but the plane did not sink below 3000ft (which was the dialed in altitude). This led me to do a manual approach, but since the weather was quite heavy (40 knots wind on the nose, heavy rain), I had to do a go around.

AP and AT were activated again and the plane was climbing to Missed Approach altitude and followed the desired route.

I wanted to do a 2nd attempt, but I was unable to insert LFRS as a destination into the FMC again. Instead, LFPG was shown as the alternate airport. So, I have manually entered the waypoints and constraints of the new STAR until the FAF. When I have reached FAF, I was unable to to make an autoland, because I got the "Discontinuity" message and AP disengaged. I was unable to tell the FMC that I wanted to land at LFRS RWY21. Any attempts to insert LFRS in the "Fight Discontinuity" line failed as well as adding "LFRS" as a new waypoint behind the FAF.

The big question is: What did I do wrong? Any help would be appreciated.  🙂

Ah, I am using Navdata from Navigraph btw...

Best regards,
Holger

[KorEl]

LFRS RW21 has no ILS, only  RW 03. You may tune the ILS, you will get the CAT category of the ILS, but there are no LOC and GS to guide the AP. So the only way for auto apr to minimums  is the RNAV apr. To follow the VNAV path for the RNAV apr in the A300 is not the same with modern a/c. You must enter the DH in the MCDU and the a/c will make the required degrees decent after reaching the FAF. See the video tutorials (RNAV apr) for the exact procedure required.  

 

[Holger]

Thanks, but this does not answer my questions...

I know that RW21 has no ILS, that's why I used RNAV. The FMC was programmed properly according to the manual / tutorial videos.

[B320Max8]

Hi!

 

First of all: there is no approach and land mode.

Only loc and land. You can arm "land" without arming loc first 

But why would you arm these on an rnav approach? 🤔

Second. Why would the plane descend below 3000 when that's the altitude that's been set in the mcp?

You would have to set it to the MDA (+ a few feet to account for reaction time).

 

It's always useful to keep track of the FMA announcements, it really helps understanding what the system does at any given moment 

Edited February 8 by B320Max8

[B320Max8]

As for the actual problem: could be a bug or deliberate,one never knows for sure. 😂I will check it myself

[Holger]

Hi,

thank you very much!

Quote

But why would you arm these on an rnav approach? 🤔

Haha, that's indeed a very good question.

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Why would the plane descend below 3000 when that's the altitude that's been set in the mcp?

Ah, okay. But that does not seem to be the solution. According to this video (it is for the A310, but I believe that it is the same in the A300)...

...it would be the Missed Approach Altitude or the Altitude of FAF (which I have used, too). NAV was armed, just as I did, but the plane did not sink.

[B320Max8]

Well, I only know how it works in the 737. 

When using an ILS you can set the missed approach altitude as soon as the plane is established on the glide.

 

When on an rnav approach you can set it at 1000 feet. Setting it earlier while result in the plane climbing again.

 

Haven't flown an rnav in the a300 yet...

 

 

[Crabby]

1. you have to be at the platform altitude in a mode other than profile (ALT hold for example)

2. Once at the platform and with the MDA set and the descent angle showing, you then arm profile descent (pull on the alt knob).  Profile descent should show on the PD as armed. 

You should be fully configured at the FAP for landing. 

[Holger]

Thank you for your replies, everyone.

I still did not manage to fly an RNAV approach yet, although I tried several approaches today. 😞

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Wenn der FMA profile descent anzeigt Dann muss auf der fcu prof taste auch die grüne lampe leuchten.

...schon klar.  😉

 

Quote

2. Once at the platform and with the MDA set and the descent angle showing, you then arm profile descent (pull on the alt knob).  Profile descent should show on the PD as armed. 

Just for my understanding (because it does not make sense to me): I am descending in PROF mode to the platform altitude (e.g. 3.000 ft). MDA and DH is set properly, AT is active. Then I need to leave PROF mode and change to ALT HLD (or whatever) and enter PROF mode again? Hmmm...

Where is the descent angle shown? I did not see it yet.

 

Another thing that bugs me is that neither the A300 or the A310 are following constraints properly. E.g. I have set ALT to 4.000 ft, but a waypoint close to me has 3.000 ft mandatory. I expect the plane to stop at 3.000 ft until passing this waypoint before climbing to 4.000 ft. Or are those old planes not capable to follow this logic?

Best,
Holger

[B320Max8]

@Holger i have to apologize, you seem to be right. I didn´t manage to fly an rnav too. The only way i got the plane to descend from the FAF was dis- and reengaging Profile mode. Which doesn´t feel right, does it. MDA had been entered correctly. I think i will make a video of this, maybe i don´t understand the system correctly...

 

 

[B320Max8]

@Crabby pulling the alt knob doesn´t arm anything on my end. At least not in regards as to what "arming" should look like in an Airbus FMA...

[B320Max8]

Then again, this could all be down to me not understanding the system correctly, coming from the likes of the Pmdg 737.

But why not just give us a 100 page or so manual, detailing the basic AFS functions???

[Crabby]

2 hours ago, B320Max8 said:

@Crabby pulling the alt knob doesn´t arm anything on my end. At least not in regards as to what "arming" should look like in an Airbus FMA...

My bad.  I was in another plane in my head.  Once at the platform altitude (the altitude that intersects the iron cross on the chart) press profile button on the mcp.  You should see P.DES arm in the PFD, if everything else is set right.  When I fly, I use profile descent to about 30 miles from the airport then I switch to LVL CHG to get down to the platform altitude.  This puts me in ALT mode when I hit that altitude.  Once there, I hit the profile button on the MCP and check that P.DES is in standby.  I know it is a little weird but remember this aircraft was released when MTV was only two years old and still ONLY played music videos.  For most, this is not your dad's VNAV it's your grandad's VNAV.  

Edited February 10 by Crabby

[Crabby]

2 hours ago, B320Max8 said:

Then again, this could all be down to me not understanding the system correctly, coming from the likes of the Pmdg 737.

But why not just give us a 100 page or so manual, detailing the basic AFS functions???

There are FCOMs available on the internet.  Just search A300-600 FCOM

[B320Max8]

7 hours ago, Crabby said:

There are FCOMs available on the internet.  Just search A300-600 FCOM

i have it right here besides me. Sadly quite a few things regarding the AFS don´t work as laid  out in the FCOM. Threre´s a few posts where i point those out.

This could be because they aren´t modelled or, and i want to stress that, i don´t understand them correctly or the FCOM simply depicts a revised version.

My point is, that a brief summary in form of a manual, depicting the basic functions, isn´t that far fetched of an idea.

 

regards

[B320Max8]

@Crabbydo you happen to have a Part 2 or wherever Airbus laid out their normal procedures?

[LukeFF]

16 hours ago, Crabby said:

There are FCOMs available on the internet.  Just search A300-600 FCOM

Players shouldn't have to search the internet for FCOMs to find out how to perform a basic procedure like a go-around. Like with the A310 manual, the A300 manual is bare-bones at best. iniBuilds really needs to start including more substantial documentation with their planes than they have released so far.

[Crabby]

1 hour ago, LukeFF said:

Players shouldn't have to search the internet for FCOMs to find out how to perform a basic procedure like a go-around. Like with the A310 manual, the A300 manual is bare-bones at best. iniBuilds really needs to start including more substantial documentation with their planes than they have released so far.

You are correct.  Players shouldn't.  Simmers who want to study a study level aircraft should.  Developers cannot give that manual with their product unless they have a specific license to do so.  That would be expensive and probably, as in the case of Boeing, a strict no go.  Your choice, but I prefer to be self-sufficient.  I know, it's weird today. 

[Crabby]

9 hours ago, B320Max8 said:

@Crabbydo you happen to have a Part 2 or wherever Airbus laid out their normal procedures?

I will and have posted snippets.  I don't want to post the whole thing because I, like the developers, don't have specific rights to do so.   However, I just searched A300-600 FCOM in Google and there are links to go get it.  There is an abbreviated FCOM available at flightsim.to courtesy of a compilation of things found on smartcockpit.com (good site too).  If you run into problems finding things, try searching for the A310 fcom because the cockpit and procedures are the same from what I can tell.  

 

[B320Max8]

5 hours ago, Crabby said:

You are correct.  Players shouldn't.  Simmers who want to study a study level aircraft should.  Developers cannot give that manual with their product unless they have a specific license to do so.  That would be expensive and probably, as in the case of Boeing, a strict no go.  Your choice, but I prefer to be self-sufficient.  I know, it's weird today. 

You are right too. But in this case I would expect the plane not to lack every other function and flight law described in said fcom. 

Also I'm not talking about including the fcom but a short 100, 200 page manual to get you started.

Back on topic, do you know how an rnav approach is actually flown (in profile mode) in the a300? Because hitting lvl chg for the plane to descend from the faf doesn't seem right to me.

[Crabby]

59 minutes ago, B320Max8 said:

You are right too. But in this case I would expect the plane not to lack every other function and flight law described in said fcom. 

Also I'm not talking about including the fcom but a short 100, 200 page manual to get you started.

Back on topic, do you know how an rnav approach is actually flown (in profile mode) in the a300? Because hitting lvl chg for the plane to descend from the faf doesn't seem right to me.

1-200 pages is A LOT. 

I have flown many RNAV approaches.  You have to first forget anything you have learned about RNAV approaches in the 737 or A320 if that is what you are used to.  Basically forget any modern aircraft procedures. 

Watch this video.  This is the simplest explanation I have seen.  EVERY step must be done. 

1. You cannot be in Profile mode (this is basically VNAV). Counter intuitive I know, but that is the way the A310 and A300 works.  Remember, Happy Days was still on TV.

2. You MUST be at the platform level before the IAF.  Not close to or at.  BEFORE.

3. You MUST enter the MDA from the chart in the TO/APPR page.  Don't enter the DH.  That is radio altitude.  Enter the MDA.  It's always the first number in the minimums section. 

4. Select Final Approach Mode by hitting the line select key next to the where it says FINAL 3.0.  It should change to show VDEV.  Dial in the FAF altitude. 

5. When pass the IAF you can hit the profile button and see P DESC armed in the PFD.  Once reach the MDA you either have to land or go around if you are not stable/can't see the runway visually.  If landing, disconnect the auto pilot.  If go around hit the toga button.  Once you are in P DESC mode on the RNAV you can dial in the missed approach altitude in case you need to go around. 

Note: I typed this from memory without being in the plane.  Just follow the video

 

[B320Max8]

black square aircraft come with a 200 page manual

justflight aircraft come with a 200 page manual

leonardo´s md 80 comes...well, you do the math

 

i´m so sorry, i really don´t want to be anal here. but if one wants to be their aircraft to be a study level one, then you better make sure it can be flown using the actual fcom.

[B320Max8]

but i think second guessing (from YT videos) is also okay.

[LukeFF]

On 2/10/2024 at 11:51 AM, Crabby said:

You are correct.  Players shouldn't.  Simmers who want to study a study level aircraft should.  Developers cannot give that manual with their product unless they have a specific license to do so.  That would be expensive and probably, as in the case of Boeing, a strict no go.  Your choice, but I prefer to be self-sufficient.  I know, it's weird today. 

I've been playing flight sims for a quarter century, during which time I've written three official operating manuals for a number of different combat flight sim titles. It's not the job of the player - of whatever skill level or interest - to hunt for info online that the developer should be providing. 

If a developer like FBW or A2A or Milviz can put together comprehensive documentation like they do, then there's no excuse for other developers like iniBuilds to not do the same thing. 

[Crabby]

53 minutes ago, LukeFF said:

I've been playing flight sims for a quarter century, during which time I've written three official operating manuals for a number of different combat flight sim titles. It's not the job of the player - of whatever skill level or interest - to hunt for info online that the developer should be providing. 

If a developer like FBW or A2A or Milviz can put together comprehensive documentation like they do, then there's no excuse for other developers like iniBuilds to not do the same thing. 

Then the community awaits you doing it.  You have written three, go for four.  Or possibly you could take the reins and negotiate an agreement with Airbus.  If is a word normally used by people who got no other option.