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Airbus oldy now a 737 newby………help!

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Airbus oldy now a 737 newby………help!

Old 29th Oct 2021, 02:18
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Airbus oldy now a 737 newby………help!

So a recent move has seen me jump from decades of bus flying to training up on the 737NG.

We are halfway through our sim training and I have some thoughts I would like to throw out in case any wiser heads would care to contribute.

1. When cleared for any VNAV path approach we set the MCP window to airfield elevation. This slightly complicates the missed approach as the PF must remember to ask for the missed approach altitude to be set once heading uphill like a cut cat! Is this a common procedure amongst 737 operators and is there a reason why we cant set the missed approach altitude once on final (I have not been permitted to try!)

2. I have never before seen takeoff performance catering to windshear including an increased VR speed as we have on the 737. I no longer have access to an Airbus FCOM but once upon a time it said “known or suspected” windshear we must “delay or divert”. And yet we are launching the 737 with known windshear! Am I missing something here? Is the Boeing windshear proof?

3. I realized today that the ND is a track up display and the rose below the PFD is a heading up display. Is this a customer arrangement and can it be changed by the crew? I find it awfully confusing to have different presentations.

Thanks in advance for any musings you may have,

cheers
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Old 29th Oct 2021, 04:42
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3. That is pin programmable, so up to customer choice. I flew both on 737s with heading up and track up NDs.

1. To be fair, i flew last on 737s with IAN, in which case any non precision approach (except non-straight in approaches) would be flown with the ILS procedure using the APProach mode. However, we still had a few old aircraft without IAN, for those we did set the MDA in the MCP, and when around 500ft above MDA set it the MCP window to missed approach altitude. The reason given for setting MDA initially was that VNAV path can revert to LVL CHG due to minimum speed reversion with less than flaps 15 selected, which could result in a rapid descent, MDA assured at least not below that. Since my books are fairly old (now on the bus for the last 5 or 6 years), airplane behavior could have been changed since.
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Old 29th Oct 2021, 06:31
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1. This is a normal procedures for all aproaches and was common even before VNAV. The logic of VNAV won't let you descent below the MCP altitude (pretty smart), so by setting MDA (not airfield elevation, at least with standard Boeing procedures) in the MCP altitude window, you let VNAV transition to final approach logic and once you are 300ft or more below the platform altitude, you can wind it back up to missed approach altitude, and VNAV will continue descending on final approach.

As Denti points out, IAN exists, but it comes with a hefty price as a customer option and not many airlines take it up.

2. Boeing guidance is the same. If windshear is confirmed, then you should delay takeoff or discontinue the approach (FCOM SP 16 has some good stuff in it). However if windshear is only suspected, you can improve aircraft's performance by rotating at the performance-limited Vr (which can be up to 20kts higher than normal Vr), to give you better performance in case that you actually end up in a windshear.

3. Track up is a customer option, that can be only changed by the airline. Personally, I never look at the compass rose below the PFD, and track up is by far superior for most phases of flying, with the odd exception of transitioning to visual part of the landing with high crosswinds, where the runway on the ND will appear straight ahead rather that left/right.
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Old 29th Oct 2021, 07:27
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The company VNAV procedure is to set airfield elevation in the MCP, and only set the go around altitude DURING the go around?? What else does the landing checklist miss out?

The altitude set in the MCP window is temporary, it just needs to be something lower than where you are - most operators pick MDA rounded down. You should never actually reach it. Once you're 300' below missed approach altitude you can reset the missed approach altitude and VNAV will ignore it.
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Old 29th Oct 2021, 10:17
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  1. We set airfield elevation on the CL rounded down and MAA is set by the PM during GA; on the NG we set the MDA rounded up and when below 300' below MAA we set MAA altitude.
  2. No one in their right mind will take off in known windshear conditions. But if you encounter it, you've got some margins.
  3. Customer option.
Different ways to skin a cat.
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Old 29th Oct 2021, 11:53
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Originally Posted by Banana Joe View Post
We set airfield elevation on the CL rounded down and MAA is set by the PM during GA; o
I'd love to see how that works with very low MAAs, such as 1500ft in BCN or 2000ft in the Netherlands.
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Old 29th Oct 2021, 13:49
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If you're flying for a certain Seattle-based airline, they're still exorcising 737-200 and -400 artifacts from the manuals.

The MAP technique is antiquated and no longer necessary as the 737CL has been retired.
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Old 29th Oct 2021, 18:06
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FlyingStone

Well, it's been like this for decades where I work, so I guess it works.
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Old 29th Oct 2021, 19:09
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ImbracableCrunk

You need to use a little care with the term '737 Classic' - not everyone agrees on the definition. Some consider the 'classic' to be the 737-100/200 series. But at least around Boeing, the general definition of '737 Classic' is the 737-3/4/500, while the even older 737-100/200 are referred to as the '737 Jurassic'.
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Old 29th Oct 2021, 22:16
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AFAIK a DAL based 737 operator sets 0000 in the window during an ILS, and doesn't set the MAA until after the GA......
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Old 29th Oct 2021, 23:01
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re 2) Airbus OEM also comes with a bit of obscure wording, suggesting to use TOGA for take-off with suspect WSHR.

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Old 30th Oct 2021, 03:24
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Well there’s windshear and there’s windshear.
Ominous CB is different from a ‘low level windshear advisory’ on the ATIS.
Anytime with gusting wind conditions you have windshear…technically.
20G30 with maybe a little rolling terrain or buildings causing mechanical turbulence.
I don’t remember the details of the 73 as I had to do a data dump for new type and I can only remember one set of everything.
I don’t see a problem with heading and track simultaneously.
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Old 30th Oct 2021, 07:53
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Like to know where you are doing your training.
Never , ever , set 0000 in the MCP.
You are setting yourself up for disaster.
On a Vnav approach set minima rounded up. When on final set missed approach alt.
The approach logic will allow you to wind the altitude away without a nuisance AltAquire.
On ILS set minima then the missed approach alt. when G/S engaged.
The trick on the B737 is to avoid unwanted AltAquire.
But never , ever 0000 in the MCP.
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Old 30th Oct 2021, 09:47
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A nice «cheat» with the compass rose on the PFD is that you can put the track line on the heading bug when on final, and you will pretty much be bang-on laterally the whole way down, without having to look over at the ND. As for the ND, I personally like track up much better there, but that of course depends entirely on personal preference
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Old 30th Oct 2021, 11:11
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The approach logic will allow you to wind the altitude away without a nuisance AltAquire.
Oh no it won't. Been there, done that (albeit in a 787, but VNAV behaves like it was programmed in the 1960s so I assume it's the same).

Set altitude increment to thousands, wind fast, then very carefully wind back down.
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Old 30th Oct 2021, 13:16
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Yes it does.
I have flown many many RNP approaches
Are you sure you are on the last route segment when you wind the Alt. away?
It works just fine.
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Old 30th Oct 2021, 16:40
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Alt Flieger

I don't work there (and fly AB), but as a jumpseater sat in the cockpit many times, and that is their procedure. Have always found it odd.
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Old 30th Oct 2021, 21:19
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Funny, with our lot, and I must admit to it myself, we wind it up rapidly with a flick and then down to the MAP, like it won't notice and snag on the way up or something. Comedy gold but it's a naturally cautious thing to do I guess. I can't think of something as stupid for an SOP as to wind MAP on during a high stress situation like a last minute go-around. Asking for trouble. really is.
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Old 30th Oct 2021, 22:22
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From our FCOM
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Old 30th Oct 2021, 23:11
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This is exactly the same in our Classic (-300/-400/-500) FCOM. The FCCs on the NG/MAX are different and allow the crew to select the MAA 300' below MAA or platform altitude if this is below MAA.
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