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"THR CLB" v. "THR LVR"?

Posted: Fri Dec 03, 2021 4:36 pm
by Martinlest
Could someone kindly explain the difference between these (particularly in respect of how an Airbus performs differently in either one, rather than what they 'mean', in theory. THR LVR is clearly a 'lower' detent). Googling hasn't really helped me with this...

Also, after taking off in FLEX mode, should I, when 'LVR CLB' is indicated on the PFD, be pulling back to THR LVR?? I always go to THR CLB (which I think is correct). Talking about X-Plane 11 here, not real-world!

Thanks. :smile:

Martin

Re: "THR CLB" v. "THR LVR"?

Posted: Fri Dec 03, 2021 4:55 pm
by Horstroad
LVR is an abbreviation for "Lever".
The Airbus thrust lever does not have a LVR or "lower" detent. There is a TO/GA detent for Maximum Take Off or Go-Around. There is a FLX/MCT detent for Maximum Continuous Thrust or Flex Take Off and there is a CL detent for Climb Thrust.
Thrust values for CL and FLX are precalculated and stored in the flight management system.
At some point after the take off (I'm sure some people here can tell you exactly when) the thrust levers should be moved from the TO/GA or FLX/MCT detent to the CL detent. The "LVR CLB" indication is a "reminder" for that. When the thrust levers are in the CL detent "THR CLB" for Climb Thrust is indicated on the PFD, as you noticed correctly.

Re: "THR CLB" v. "THR LVR"?

Posted: Fri Dec 03, 2021 10:52 pm
by Woodreau
LVR CLB flashes to indicate that the aircraft is above thrust reduction altitude set in the FMGC and the thrust levers have not been retarded to the CLB detent.

THR CLB indicates that the thrust mode is fixed and that the aircraft will use pitch to achieve the selected or managed speed instead of using variable thrust to maintain the selected or managed speed.

Re: "THR CLB" v. "THR LVR"?

Posted: Sat Dec 04, 2021 1:30 am
by Starlionblue
Horstroad wrote:
LVR is an abbreviation for "Lever".
The Airbus thrust lever does not have a LVR or "lower" detent. There is a TO/GA detent for Maximum Take Off or Go-Around. There is a FLX/MCT detent for Maximum Continuous Thrust or Flex Take Off and there is a CL detent for Climb Thrust.
Thrust values for CL and FLX are precalculated and stored in the flight management system.
At some point after the take off (I'm sure some people here can tell you exactly when) the thrust levers should be moved from the TO/GA or FLX/MCT detent to the CL detent. The "LVR CLB" indication is a "reminder" for that. When the thrust levers are in the CL detent "THR CLB" for Climb Thrust is indicated on the PFD, as you noticed correctly.


The point after the takeoff when you are reminded to pull the thrust levers back to the CL detent is the thrust reduction altitude, typically somewhere between 800 and 1500 feet AAL. The thrust reduction altitude is shown on the Performance-Climb page in the MCDU.

Re: "THR CLB" v. "THR LVR"?

Posted: Sat Dec 04, 2021 4:39 pm
by Martinlest
OK, thanks. So CLB LVR is not a 'thrust mode' then, as is CLB THR (if I have understood you correctly), it's just an indication to move the levers down from FLEX or TOGA. My procedure has always been OK, but I was assuming CLB LVR to be a detent (though that didn't make much sense to me - hence the post)... :smile:

Re: "THR CLB" v. "THR LVR"?

Posted: Sun Dec 05, 2021 1:44 am
by Starlionblue
Martinlest wrote:
OK, thanks. So CLB LVR is not a 'thrust mode' then, as is CLB THR (if I have understood you correctly), it's just an indication to move the levers down from FLEX or TOGA. My procedure has always been OK, but I was assuming CLB LVR to be a detent (though that didn't make much sense to me - hence the post)... :smile:


You have indeed been doing it correctly.

The flashing indication is "LVR CLB", (not CLB LVR), indicating you should set climb thrust. The appropriate thrust lever detent detent is "CL".

The thrust mode will change from TOGA/FLX/DRT to THR CLB (or THR DCLB1/2 with a climb derate). The vertical mode will change from SRS to CLB. In this vertical mode, thrust is fixed*, with speed being controlled by pitch.

Image


* If we want to nitpick, thrust isn't quite fixed, as FADEC will adjust for environmental conditions. If you use a derate this will gradually wash out as you climb.

Re: "THR CLB" v. "THR LVR"?

Posted: Sun Dec 05, 2021 10:17 pm
by Martinlest
"The flashing indication is "LVR CLB", (not CLB LVR)"

Indeed! :-) As I say, my question stemmed from imagining LVR CLB to be a detent rather than an instruction. All good! Thanks.

Re: "THR CLB" v. "THR LVR"?

Posted: Tue Dec 07, 2021 5:04 pm
by FlapOperator
If you really want to go realistic, make sure you verbalize all FMA changes, from left to right starting with takeoff.

For example, "MAN FLEX, SRS, AUTOTHRUST BLUE"

Here is a good link on the Airbus FMA...

https://blog.thea320insider.com/2021/07 ... iator-fma/

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 08, 2021 1:48 am
by Starlionblue
FlapOperator wrote:
If you really want to go realistic, make sure you verbalize all FMA changes, from left to right starting with takeoff.

For example, "MAN FLEX, SRS, AUTOTHRUST BLUE"

Here is a good link on the Airbus FMA...

https://blog.thea320insider.com/2021/07 ... iator-fma/


Make sure you say the Flex number too. ;)

"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".

Once in the climb phase, "Thrust climb, climb, autothrust."

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 08, 2021 2:01 am
by FlapOperator
Starlionblue wrote:
FlapOperator wrote:
If you really want to go realistic, make sure you verbalize all FMA changes, from left to right starting with takeoff.

For example, "MAN FLEX, SRS, AUTOTHRUST BLUE"

Here is a good link on the Airbus FMA...

https://blog.thea320insider.com/2021/07 ... iator-fma/


Make sure you say the Flex number too. ;)

"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".

Once in the climb phase, "Thrust climb, climb, autothrust."


Good point. Its been awhile since I've been saying that. I tried to find a good source from Airbus that had the verbalizations.

At USS Last Company, we verbalized all changes to include ALT STAR, ALT and few others I've never seen during LOSA evals.

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 08, 2021 3:03 pm
by Woodreau
GLIDESLOPE STAR, GO AROUND ALTITUDE SET THREE THOUSAND WHITE.

these new EIS updates are making up all sorts of new colors to verbalize, MAGENTA, BLUE, WHITE... i wonder whats next GREEN?

Re: "THR CLB" v. "THR LVR"?

Posted: Tue Dec 14, 2021 5:01 pm
by Martinlest
Make sure you say the Flex number too. ;)
"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".
Once in the climb phase, "Thrust climb, climb, autothrust."


Yes, I don't actually talk to myself like that in X-Plane, but point noted! :)

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 15, 2021 12:43 am
by Starlionblue
Martinlest wrote:
Make sure you say the Flex number too. ;)
"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".
Once in the climb phase, "Thrust climb, climb, autothrust."


Yes, I don't actually talk to myself like that in X-Plane, but point noted! :)


I do call the modes in X-Plane. But to each their own. ;)

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 15, 2021 1:27 am
by Woodreau
Martinlest wrote:
Make sure you say the Flex number too. ;)
"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".
Once in the climb phase, "Thrust climb, climb, autothrust."


Yes, I don't actually talk to myself like that in X-Plane, but point noted! :)


I believe most if not all Airbus pilots verbalize the FMA when the mode changes as that is the procedure that Airbus teaches.

So if you really want to fly X-Plane the “proper” way, you’ll be talking to yourself a lot flying the Airbus,
And if you dont, your PM will be verbalizing your FMA changes for you.

Sometimes it’s a game, who can call “1000” before the other guy.

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 15, 2021 1:42 am
by Starlionblue
Woodreau wrote:
Martinlest wrote:
Make sure you say the Flex number too. ;)
"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".
Once in the climb phase, "Thrust climb, climb, autothrust."


Yes, I don't actually talk to myself like that in X-Plane, but point noted! :)


I believe most if not all Airbus pilots verbalize the FMA when the mode changes as that is the procedure that Airbus teaches.

So if you really want to fly X-Plane the “proper” way, you’ll be talking to yourself a lot flying the Airbus,
And if you dont, your PM will be verbalizing your FMA changes for you.

Sometimes it’s a game, who can call “1000” before the other guy.


The aircraft tells us "1000" so we cannot win this game. ;) I guess that's an operator setting.

If the PF misses the call, it is customary with us for the PM to wait until the frame disappears from the new mode annunciation before announcing.

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 15, 2021 2:22 am
by Woodreau
Yes we wait until the white box disappears before the PM verbalizes what the PF is supposed to verbalize.

I’ve never heard an Airbus call 1000 to level. e.g. FL360 to FL370. There is no altitude c-chord when the autopilot is engaged. If the autopilot is not engaged the altitude alerter sounds at 700ft to level but our callout is to verbalize “1000” to level. That is probably not an Airbus thing but our own internal airline thing.

I’ve heard it call 1000 RA though but usually it’s at the wrong altitude because it’s 1000 RA not 1000ft above TDZE in which case we’re supposed to call the “1000” at the proper place like going into Seattle or Las Vegas or Los Angeles where the 1000 altitude autocallout is in the wrong place.

Re: "THR CLB" v. "THR LVR"?

Posted: Wed Dec 15, 2021 5:25 pm
by FlapOperator
Martinlest wrote:
Make sure you say the Flex number too. ;)
"MAN FLEX fifty-seven, SRS, (runway,) autothrust blue".
Once in the climb phase, "Thrust climb, climb, autothrust."


Yes, I don't actually talk to myself like that in X-Plane, but point noted! :)


Its not verbalizing just for the other pilot. Its Airbus operator logic where man/machine integration requires what an Airbus Navigator (I think that's the term) said everything should be verse/chorus.

So, the aircraft says "STALL, STALL" and the pilot flying response is "Stall, I have control." Essentially for most operations, the plane says something, you repeat and do the action.