Misc Questions

[NoslenYL]

Hey guys,

I just finished all of the included tutorial flights for the 733, but I had a few questions that I would prefer to get clarification on before taking the plane online. There's a whole (metric) ton of confusion here (I'm new to glass cockpits in general - been using VORs for as long as I can remember), so I just decided to list them below (yes I checked online for manuals and stuff first...) - any help would be *greatly* appreciated.

1. I'm a tad bit confused about the mcp speed setting on takeoff. I know you're supposed to set it to V2, but I read something online talking about the autopilot automatically pitching for V2+15? I thought the autopilot would attempt to hold V2 until the acceleration height, when the speed automatically increases? Also, if that is true and the autopilot will try to hold V2, why would the pilot not enter V2+15 into mcp before departure for the maneuvering speed?
2. During a descent along a profile STAR, if ATC gives me a shortcut and unplanned descent, then tells me to resume the arrival, after coming out of VS/LVL CHG would I be able to just reactivate VNAV and LNAV or do I have to manually fix something in the fmc first?
3. I know that when descending, LVL CHG, VNAV, and VS won't go below the altitude selected on the mcp, but on final approach when you're dialing in the missed altitude into the mcp it continues the descent? Does the mcp altitude being a "hard barrier" not apply if you manually adjust it up?
4. For T/C and T/D, why don't the green arc and the actual circle on the flight path in map mode line up? The arc will just continue to get closer to the circle until they're on top of each other - they both seem to be accurate. I'm assuming this is because of the way the arc and the T/C and T/D circles are calculated in relation to the aircraft's position, but I'd like to figure out why it does that.
5. On the top left of the EFIS display, where it shows --.- NM, what would that be showing? Is it one of the un-modeled systems (couldn't find a mention of it on the un-modeled systems post)? I'm assuming it's something I'm doing wrong, but I'm not sure - I don't think it ever showed a number throughout the tutorial flights.
6. While VNAV is flying an approach, why does the speed go from fmc speed to armed (i.e. during the last tutorial flight). I know LVL CHG would cause the auto throttles to go into the armed state, but if VNAV is still controlling the vertical profile (i.e. I haven't disengaged it yet), why would it change to armed? I'm not sure if I remember correctly, but I think it may have gone back into fmc speed mode again after being armed for a few seconds (something happened that cause me to put my "404: does not compute" face on...)
7. For the descent page in the fmc, E/D ALT from what I could find online means end of descent altitude? But if my mcp setting is around 5000, how is the end of descent at 1400? Also, next to the flight path angle why are there 2 vertical speeds? And under "TO CBY" I have no idea what the 1719.8z means...
   1. 

Curiosity Questions

1. I know you can't have both the weather and terrain radars overplayed on the EFIS display at the same time (though in the real 733 I think you can have wx on one side and terrain on the other?), but I was just wondering how the plane knows which one of the two I want displayed if both switches are in the on position? I'm assuming it just displays the one that I turned on last, but if that's the case, why doesn't the plane just turn the switch for the other one off?
2. I know that practically there's no use for the wipers when you're not taking off or landing (the rain is just blown off and the wipers are quite* annoying), but is there any physical restriction for the 733 that says the wipers shouldn't be operated above a certain threshold?
3. On the climb page of the FMC, the engine out option doesn't seem to do anything when I clicked it? Is it just not modeled, or am I just doing something wrong?
4. I know you can't arm / activate LNAV until 400 agl in the -300. Is it the same altitude for VNAV?

Possible Bugs?

1. Pretty sure 1016 millibars = 30.00 inches mercury, but the plane shows 30.01 (sue me for being a perfectionist)

 

Did anyone actually read this far?

[Tchou]

I'll answer some of these : 

2 i'd activate the next waypoint of the approach (select it in the legs page, and copy it from the scratchpad to the first one) 

3 On final approach you've already reached the altitude where you catch the glideslope. so you are following and ILS or the plane is on VS mode or your are flying manually so you can select an altitude, it's not taken into account unless you select a LVL CHG, or Go around or a positive VS mode.

5 it should show the distance to your next waypoint, but it's not modeled yet

6 it's the autothrottle that goes to ARM  mode, when descending it goes to retard mode (Idle power) then arm itself to reengage when altitude is reached or is rate of speed is too high (it will then take a less steep descent then put enough power to not slow down).

7 I think this page is WIP so some info in it may be a little bit funky 1719.8z is supposed to be a time for example. End of descent might be the altitude where you are supposed to catch your glideslope or the airport altitude

 

CQ1 : terrain radar will take place over weather radar so if WR is on with TR off => WR displayed

WR is on with TR ON => TR displayed.

CQ2 : I guess as the flaps and others, they could get damaged but is there a specific speed IDK

CQ3 : Not modeled yet

PB : rounding issue I guess but it could be an X-plane issue, I have to check on other planes. 

Edited June 21, 2016 by Tchou

[Litjan]

On 21.6.2016 at 7:34 AM, NoslenYL said:

Hey guys,

I just finished all of the included tutorial flights for the 733, but I had a few questions that I would prefer to get clarification on before taking the plane online. There's a whole (metric) ton of confusion here (I'm new to glass cockpits in general - been using VORs for as long as I can remember), so I just decided to list them below (yes I checked online for manuals and stuff first...) - any help would be *greatly* appreciated.

1. I'm a tad bit confused about the mcp speed setting on takeoff. I know you're supposed to set it to V2, but I read something online talking about the autopilot automatically pitching for V2+15? I thought the autopilot would attempt to hold V2 until the acceleration height, when the speed automatically increases? Also, if that is true and the autopilot will try to hold V2, why would the pilot not enter V2+15 into mcp before departure for the maneuvering speed?
2. During a descent along a profile STAR, if ATC gives me a shortcut and unplanned descent, then tells me to resume the arrival, after coming out of VS/LVL CHG would I be able to just reactivate VNAV and LNAV or do I have to manually fix something in the fmc first?
3. I know that when descending, LVL CHG, VNAV, and VS won't go below the altitude selected on the mcp, but on final approach when you're dialing in the missed altitude into the mcp it continues the descent? Does the mcp altitude being a "hard barrier" not apply if you manually adjust it up?
4. For T/C and T/D, why don't the green arc and the actual circle on the flight path in map mode line up? The arc will just continue to get closer to the circle until they're on top of each other - they both seem to be accurate. I'm assuming this is because of the way the arc and the T/C and T/D circles are calculated in relation to the aircraft's position, but I'd like to figure out why it does that.
5. On the top left of the EFIS display, where it shows --.- NM, what would that be showing? Is it one of the un-modeled systems (couldn't find a mention of it on the un-modeled systems post)? I'm assuming it's something I'm doing wrong, but I'm not sure - I don't think it ever showed a number throughout the tutorial flights.
6. While VNAV is flying an approach, why does the speed go from fmc speed to armed (i.e. during the last tutorial flight). I know LVL CHG would cause the auto throttles to go into the armed state, but if VNAV is still controlling the vertical profile (i.e. I haven't disengaged it yet), why would it change to armed? I'm not sure if I remember correctly, but I think it may have gone back into fmc speed mode again after being armed for a few seconds (something happened that cause me to put my "404: does not compute" face on...)
7. For the descent page in the fmc, E/D ALT from what I could find online means end of descent altitude? But if my mcp setting is around 5000, how is the end of descent at 1400? Also, next to the flight path angle why are there 2 vertical speeds? And under "TO CBY" I have no idea what the 1719.8z means...
   1. 

Curiosity Questions

1. I know you can't have both the weather and terrain radars overplayed on the EFIS display at the same time (though in the real 733 I think you can have wx on one side and terrain on the other?), but I was just wondering how the plane knows which one of the two I want displayed if both switches are in the on position? I'm assuming it just displays the one that I turned on last, but if that's the case, why doesn't the plane just turn the switch for the other one off?
2. I know that practically there's no use for the wipers when you're not taking off or landing (the rain is just blown off and the wipers are quite* annoying), but is there any physical restriction for the 733 that says the wipers shouldn't be operated above a certain threshold?
3. On the climb page of the FMC, the engine out option doesn't seem to do anything when I clicked it? Is it just not modeled, or am I just doing something wrong?
4. I know you can't arm / activate LNAV until 400 agl in the -300. Is it the same altitude for VNAV?

Possible Bugs?

1. Pretty sure 1016 millibars = 30.00 inches mercury, but the plane shows 30.01 (sue me for being a perfectionist)

 

Did anyone actually read this far?

Hi Noslen,

I read that far - and will answer you in detail when I have a second (or actually half an hour...) . Cheers, Jan

 

[NoslenYL]

Cheerios guys, thanks for the time. To be completely honest, I kind of wasn't any replies at all, so muchas gracias!

[Litjan]

Alright, let´s see...

1.) The autopilot will normally target V2+15 (actually up to V2+25, iirc). V2 is the speed that will be flown exactly if you have an engine failure, thats why it is being set with the orange cursor. V2 is Vstall x 1.2 - but it won´t allow more than 15 deg bank, thats why V2+15 is flown under normal conditions (bank up to 30 ok).

2.) You should be able to resume LNAV and VNAV navigation upon rejoining (or going direct to a point) of your old arrival. VNAV is still under improvement works - so keep an eye on how that performs and be ready to revert to V/S or FL CHG if it is unsatisfactory.

3.) The MCP hard barrier does not apply for the G/S pitch mode.

4.) The green circles are calculated taking diminishing performance with altitude into account (the plane is not climbing linearly). The "banana" is always "present ground speed vs present climbrate" - so it will be too optimistic during climbs, and too pessimistic during descents (since the groundspeed diminishes when lower).

5.) This should show distance to current active waypoint - but it is currently still missing and will be added in 1.1

6.) That is still being tuned - but the first descent after the T/D will be an idle-power gliding descent. The autothrottle retards the engines to idle, then goes to armed. The autopilot will keep the plane on the pre-planned path - ideally the slope is such, that the plane can "glide" at the precomputed speed without any engine thrust. If things don´t work out (too much headwind, etc.), the engine will spring back to life (FMC SPD) to boost speed back to the desired level. Then it will go dormant again...

7.) The E/D point is the last and lowest point in the route (usually the runway altitude + 50 feet) - the MCP ALT has nothing to do with the FMS´ path calculation - but will be heeded by the autopilot for level-off, if the pilot is not quick enough to "dial it out of the way". The three labels should actually be FPA (current flight path angle), VBA (vertical bearing to next altitude restriction) and V/S (required vertical speed to make the next restriction). This will be fixed and tuned in future updates. 1719.8 is the predicted time in Zulu time for CBY.

Q1: The terrain display overpowers the wxr display - if both are on, terrain will be shown.

Q2: There is a maximum wiper speed, but I don´t remember it right now. It is pretty high, though, so it is not a real limitation (since you will only use the wipers during approach, takeoff and taxiing.

Q3: Engine out FMS mode is not modeled yet.

Q4: Limitations say minimum 1000 feet agl, but you can already engage that at 400 as well.

Hope this helps, Jan

 

Edited June 23, 2016 by Litjan

[NoslenYL]

Thanks a lot Jan, that was really informative. I appreciate all the time you're putting in to answer all these questions! Greatly appreciated!

[NoslenYL]

One more thing  If I'm on a SID and I get cleared to an altitude unrestricted, is there a way I can delete the altitude restrictions on the FMC or do I just have to manually climb to the altitude before reengaging VNAV?

[mmerelles]

2 hours ago, NoslenYL said:

One more thing  If I'm on a SID and I get cleared to an altitude unrestricted, is there a way I can delete the altitude restrictions on the FMC or do I just have to manually climb to the altitude before reengaging VNAV?

you go to the fmc climb page and delete the altitude restriction there. press DELETE and press the corresponding soft key on the fmc screen

 

edit: it is also quite important you reset the mcp alt to authorized altitude, otherwise mcp alt acts as a fence and the aircraft won't climb beyond that.

 

 

Edited June 24, 2016 by mmerelles

[Tom Stian]

2 hours ago, NoslenYL said:

One more thing  If I'm on a SID and I get cleared to an altitude unrestricted, is there a way I can delete the altitude restrictions on the FMC or do I just have to manually climb to the altitude before reengaging VNAV?

I use LVL CHG in cases like that. I think thats a more efficient way of doing it, in my opinion.

[mmerelles]

5 minutes ago, Tom Stian said:

I use LVL CHG in cases like that. I think thats a more efficient way of doing it, in my opinion.

yes and no!

climb & maintain XXX states to initiate an unrestricted climb to XXX (any altitude restriction from your present altitude up to XXX gets delered) which doesn't mean you can violate speed restrictions that may exist on the procedure!

if there is no speed restriction you can climb FLCH at no problem, but VNAV will still take care of speed restrictions for you. You may still climb FLCH but you must also keep accommodating speed restriction on the MCP SPD dial if any!

[NoslenYL]

Hmm, actually it wouldn't let me delete anything from the climb page. I fiddled around some and hitting delete + the right LSK (next to the speed / altitude) worked for me. I was confused because I didn't realize that deleting the restrictions for the next waypoint would also reset the waypoints after that up to the cruise level. It did also seem to delete all the speed restrictions as well, so I'm assuming that either you have to re-enter those manually or there's a way to only delete the altitudes and not speeds that I'm missing...

 

PS - I was planning to test this later, but thought I would also put it here. I'm assuming since holds aren't a part of v1, the FMS also won't be able to do procedure turns on an approach? An example would be the ILS 20R at KSNA, where there's a teardrop reversal at SAGER. The FMS does draw the hold, but I'm assuming it doesn't know how to fly it? KSNA ILS 20R - https://skyvector.com/files/tpp/1607/pdf/00377IL20R.PDF

Edited June 24, 2016 by NoslenYL

[TDPlane]

I'm used to get the ATC-ruling "Speed is Yours" when there's no speed restriction ...

[Litjan]

12 hours ago, NoslenYL said:

Hmm, actually it wouldn't let me delete anything from the climb page. I fiddled around some and hitting delete + the right LSK (next to the speed / altitude) worked for me. I was confused because I didn't realize that deleting the restrictions for the next waypoint would also reset the waypoints after that up to the cruise level. It did also seem to delete all the speed restrictions as well, so I'm assuming that either you have to re-enter those manually or there's a way to only delete the altitudes and not speeds that I'm missing...

 

PS - I was planning to test this later, but thought I would also put it here. I'm assuming since holds aren't a part of v1, the FMS also won't be able to do procedure turns on an approach? An example would be the ILS 20R at KSNA, where there's a teardrop reversal at SAGER. The FMS does draw the hold, but I'm assuming it doesn't know how to fly it? KSNA ILS 20R - https://skyvector.com/files/tpp/1607/pdf/00377IL20R.PDF

Don´t delete stuff on the CLIMB page, it is mostly for viewing your current limitiation - you can delete/edit the speed restriction altitude and speed, though.

To manage your restrictions, go to the LEGS page and change them there.

Your mileage with procedure turns and teardrops may vary - I am not quite sure how they hold up right now ;-)

Jan

 

Edited June 25, 2016 by Litjan