Side stick vs conventional Yoke

Boeing 737-8 guys, what's is "LAVS to the feather" on approach? Read an ASAP newsletter for the Delta fleet of 737s, and it talked about this technique LAVs to the feather for an approach? Not sure of LAVS part, but something like that to the feather?
 
Cherokee_Cruiser said:
Boeing 737-8 guys, what's is "LAVS to the feather" on approach? Read an ASAP newsletter for the Delta fleet of 737s, and it talked about this technique LAVs to the feather for an approach? Not sure of LAVS part, but something like that to the feather?
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Not a 738 guy but here's how it would apply to the 75/76...My guess is that the ASAP was in reference to tracking the GS outside the usable range and therefore busting mandatory step downs on the ILS prior to "the feather." LAVS refers to remaining in LNAV/VNAV on an approach and therefore would honor published step downs because they are preprogrammed in the FMS. Basically it's an acronym that we use to correctly manage the autopilot for an approach. Specifically an RNAV approach but in the case of using LNAV/VNAV in lieu of just selecting the APP button on an ILS outside the feather you're essentially flying an ILS as an RNAV approach. Once you are "on the feather" you would simply select APP and fly the LOC/GS which you will already probably be on or at worst very nearly so...

L- LNAV
A- Set field elevation rounded up to nearest 100
V- VNAV
S- Speed intervene

This method of staying in LNAV/VNAV works extremely well in a place like LAX when you are transitioning from the SEAVU2 arrival to the ILS 25L. There's a REALLY long final on the LOC with a bunch of step downs providing ample opportunity to bust a restriction if you hitch up too soon on the GS.
 
jrh said:
Honest question: What is so dangerous about flying an ILS through the clouds? Be it hand flown, raw data, with a flight director, autopilot coupled, whatever.
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Nothing really is dangerous about flying an ILS through the clouds. I could argue though that it's safer to have the autopilot fly it while I monitor it and the non-flying pilot does his tasks.

Keep in mind most of us here are pilots talking in the context of flying for a company. Our companies have manuals and procedures that in most cases they'd like us to follow in the interest of increased safety. We're paid to do it their way but we're not completely hamstrung to deviate from their procedures when necessary. Example- +/-10 knot gusts all the way down the final, the autopilot is bucking like a bronco, any one of us is clicking it off and taking over, why? We're allowed to and it's safer and smarter.
 
Cherokee_Cruiser said:
Boeing 737-8 guys, what's is "LAVS to the feather" on approach? Read an ASAP newsletter for the Delta fleet of 737s, and it talked about this technique LAVs to the feather for an approach? Not sure of LAVS part, but something like that to the feather?
Click to expand...

It's VNAV to the feather, basically. On the 75/76 and 737 it's the same "LAVS" to get into a VNAV path descent in order to respect all the crossing altitudes until hitting the GS intercept altitude.

We do likewise on fifi, just it's managed to the feather.

It is critical to do so when OAT is warm, as GS tends to fall below the step down altitudes as it gets higher and higher above standard. In some cases it's just downright below the step down even when not super warm! Off the top of my head, LAX, SLC, and ATL have had a number of violations with guys following the GS instead of the step downs on warm days.
 
Baronman said:
Keep in mind most of us here are pilots talking in the context of flying for a company. Our companies have manuals and procedures that in most cases they'd like us to follow in the interest of increased safety.
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I hear ya. I used to fly for a commuter airline and am familiar with all the standardization and company procedures. It just seems like an odd debate to have, on both sides of the coin.

I look at the situation and think, "Meh, either way is really, really safe, why is everyone debating it?"
 
Ok, thanks for the responses. LAVS to the feather sounds too complicated. I just set the lower altitude and push the alitude button, let Fifi handle the rest (monitor to make sure it does what you want, of course).
 
Cherokee_Cruiser said:
Ok, thanks for the responses. LAVS to the feather sounds too complicated. I just set the lower altitude and push the alitude button, let Fifi handle the rest (monitor to make sure it does what you want, of course).
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How is the LAVS procedure any different than engaging LNAV (or ensuring it's already done), dialing in a lower altitude, pushing managed descent, and pushing managed speed or dialing a set speed on the Airbus? On an ILS you're still going to eventually engage the ILS correct? It's the same thing!
 
Cav said:
How is the LAVS procedure any different than engaging LNAV (or ensuring it's already done), dialing in a lower altitude, pushing managed descent, and pushing managed speed or dialing a set speed on the Airbus? On an ILS you're still going to eventually engage the ILS correct? It's the same thing!
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In Soviet France, Airbus engages YOU!
 
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Cherokee_Cruiser said:
Ok, thanks for the responses. LAVS to the feather sounds too complicated. I just set the lower altitude and push the alitude button, let Fifi handle the rest (monitor to make sure it does what you want, of course).
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It's the same thing.

Managed nav- L
set the altitude- A
managed descent- V
selected speed- S
 
Cherokee_Cruiser said:
But it should just be LAV, if you set up the perf descent phase properly :) But then again, we start saying LAV, and someone is gonna think you have to go to the bathroom. ;)
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LAVS works! If you're on an assigned speed coming down the approach like usual, you should be on selected speed with approach phase active at least before 10k. No managed speed until ready to slow fully.

We're talking about coming down an ILS final here, not flying a STAR. :)
 
PeanuckleCRJ said:
LAVS works! If you're on an assigned speed coming down the approach like usual, you should be on selected speed with approach phase active at least before 10k. No managed speed until ready to slow fully.

We're talking about coming down an ILS final here, not flying a STAR. :)
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True. Our procedures are to set the descent speed in the perf page and descent in managed speed (selected speed if ATC assigned something else). As the aircraft slows to 250 nearing 10k, our procedure is to select speed 250 and activate approach through 10k. So I guess it is LAVS but it doesn't feel as complicated as that report made it sound like.
 
Cherokee_Cruiser said:
True. Our procedures are to set the descent speed in the perf page and descent in managed speed (selected speed if ATC assigned something else). As the aircraft slows to 250 nearing 10k, our procedure is to select speed 250 and activate approach through 10k. So I guess it is LAVS but it doesn't feel as complicated as that report made it sound like.
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Yep! same thing... on the Boeing it's just making sure the speed window is open since you don't have an approach phase to activate. The FMS is much more user friendly on the Boeings, sad to say.

LAVS isn't complicated, it's just a verification that the plane is set up to laterally and vertically to honor the path for the approach. We do the same thing on fifi, there's just no fun acronym!
 
"Activating the approach" on the Airbus may be once of the most needlessly worthless steps in all of aviation.
 
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