Autoland question

[Alpha Floor 237]

Sorry to hijack this thread, but I was curious about when exactly the crew is expected to be at full landing configuration (25 or 30 landing flaps/spoilers armed/gear down) in relation to the FAF during autolands. 

 

Is it policy to be at this config, and at VREF+5, before and at the OM/FAF when I intercept the glideslope from level flight?   Is this what you mean by "platform altitude"?   I know we have some leeway in visual approaches, or non autoland ILS approaches (CAT I), where one can intercept the glideslope as instructed by ATC without having to level off before hand (i.e. CDA).  From what I have figured out, it seems during ILS approaches in real bad weather with low visibility/ceilings, whether the pilot utilizes CAT I/II/III, it would be ideal to level off at the glideslope intercept altitude (about 2000ft AGL) a few miles ahead so that the crew can adequately prepare for slowing to final approach speed, which would be very difficult to accomplish while descending on the glideslope.

 

I remember hanging out at my cousin's house on Long Island NY one day, and he lived a few miles away from the OM for KJFK ILS 22L.   On this particular day, it sounded like traffic was flying lower than normal, as if they were level in the "platform" altitude.   He lived in a very affluent area, and I would think the neighbors would not be very tolerant of the noise, so ever since that day I have always associated bad weather approaches with a requirement to be low and slow much in advance relative to approaches in nicer weather. 

 

Hope this question makes sense. 

 

As a rule of thumb, you should be completely configured for landing and on a gentle glide BEFORE reaching 1000 AGL. This is what's known as a "stabilized approach"

 

On the 737's FCTM they list all the elements a stabilized approach should have under 5.3. If the approach is unstabilized below 1000 ft under IMC, or 500 ft under VMC, then a go-around should be executed. These are the minimum requirements by Boeing, some airlines may raise those requirements to 1000 ft under every condition, or 1500 ft for all standard ILS approaches. There are some special approaches that have to be considered a part.

 

Some of the elements of a stabilized approach are:

- Speed is not more than Vref + 20

- Sink rate not greater than 1000 fpm

- Aircraft in landing configuration

- On an ILS: deviation of G/S or LOC not greater than one dot.

 

Also, yes it's nice to have 5 nm leveled at GSIA (glideslope intercept altitude) to have time to configure the aircraft and slow down. But sometimes due to congested traffic crews don't have that "luxury" and ATC instructs them to intercept the GS from above or at a higher speed. On bad weather days, it makes sense that ATCs and pilots take more cautions and have the aircraft intercept the ILS more "comfortably". That's why bad weather and lots of traffic almost always means delays.

[pete_auau 1,158]

Can someone please tell me if this sequence is correct for an autolanding? Once low and close enough to the G/S, click VOR lock then APP, after G/S capture engage both Autopilots, then thats it. 

 

Since I cant add my name in a signature until April 11th, I'll just put it here.

 

                  -Ben Angelo

 

Thought watching  a vid  might help

https://www.youtube.com/watch?v=I_lxOSC3cws

[Fabo 213]

I do have a couple of reservations with that gentlemans video... some of his flying and talking is confusing, some of it plain wrong. And some just not neighbourly.

 

So naturally I will try and warm my own soup (as we say over here ), also in a bit more typical configuration (no FAIL OP option, no HGS).

 

 

 

 

These are the minimum requirements by Boeing, some airlines may raise those requirements to 1000 ft under every condition, or 1500 ft for all standard ILS approaches.

 

Engines not at idle is also a common consideration.

 

 

 

 

Sorry to hijack this thread, but I was curious about when exactly the crew is expected to be at full landing configuration (25 or 30 landing flaps/spoilers armed/gear down) in relation to the FAF during autolands. 

 

Depends on the airline. I am used to the same "being stable at the latest at 1000 ARL/AAL" Especially when not in actual LVP, it helps to just go with the flow which will often be 160kts until 4 or 5 miles. IIRC I keep similar speed schedule in the video.

 

 

 

Is this what you mean by "platform altitude"?

 

Platform altitude is the altitude that FAF is at, meaning, where the aircraft would enter the glideslope from a level flight per design of procedure. Typically somewhere at 2000-3000ft AAL.

There are some other ways to enter the glide, as you mention - there is the increasingly more popular CDA, continuous descent approach, or you might also elect to enter glideslope from below, but higher, if the conditions are right. Both help alleviate noise.

[NGXfanatic 85]

 That's why bad weather and lots of traffic almost always means delays.

 

Good point.  It's a known fact that whenever there is bad weather or fog, there are invariably delays for arrivals.  I assume that ATC increases separation between aircraft during finals and vectors to finals when traffic is in the "soup", presumably, this means ATC is even more strict with speed restrictions and such when everyone is flying blind. 

 

Thanks for the replies, it's helpful to know when and if I run into some heavy overcast conditions, which we can finally experience with some authenticity with ASN!

[rfresh737 36]

Please see page 5.14 of the Flight Training Manual -- Autopilot ILS approach -- Fail Operational.

 

The exact sequence of steps and when to do them is spelled here on this one page. This is the Boeing default ILS auto land sequence.

 

Initial approach flaps (5) and when to put the landing gear down may be modified as determined by the Captain. For example, I like to fly the CRESO3 STAR going into Las Vegas (KLAS) from Los Angeles (KLAX). This is a challenging STAR to fly because it is a relatively tight STAR, therefore, I modify the default Boeing ILS auto land sequence by flying my initial approach configuration at flaps 15 and I put the gear down before turning onto the localizer and getting the GS alive visual cue (the normal spot to put the gear down). This is perfectly fine to do. My point in saying all of this is that the book may say do something here or there but in the real world, you may not be able to or may not want to. It's ok to make small adjustments from the default step sequences. Be aware the steps are not cast in stone!

 

Note re this STAR: this is not a star ATC uses when vectoring aircraft into KLAS (not a preferred route). The CRESO3 would most likely be flown only if you lost all comm radios. I like to fly it once in a while because it is a challenging STAR to fly on the auto pilot. In my sim flying I don't get involved with ATC too much.

 

I always fly with the auto pilot and my BBJ is configured for Fail Operational auto land (configured on the CDU).

 

Happy flying.

[pete_auau 1,158]

Please see page 5.14 of the Flight Training Manual -- Autopilot ILS approach -- Fail Operational

Don't tell me you found this information in the manuals

[scandinavian13 5,192]

 

 

Once low and close enough to the G/S, click VOR lock then APP, after G/S capture engage both Autopilots, then thats it.

 

Everyone else is doing a great job of giving you advice on what to do, but I noticed "VOR lock" which drives me up a wall, so I figured I'd just point out that it's "VOR/LOC," pronounced "V - O - R, Loke."  The LOC doesn't stand for LOCK.  It stands for LOCalizer.  It's basically like using APP mode without any vertical guidance, and as mentioned by a few others, it is not necessary to hit LOC before APP.

[diego84 0]

Hi,

 

I saw this video some time ago, maybe it helps.

 

 

 

 

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Diego Dc