hello all

 

I recently read a post from Kyle that to fly more realistic, you should press the Autopilot disc button 2 times. But, I have a few questions about  that.

is there a key assignment, pure for disconnecting? 

-And, that is how it is done after touchdown? After the roll out is done? 

-So, what I do now (just moving the controller to the left till ti disconnects) isn't right (realistic)? 

-And will it work in the 777 (so I don't have to press the invisible click point)?

 

vkr

victor roos

 

ps: just found this.. I'll take a look at it now

 

How does that differ from the 777?

Edited April 9, 201511 yr by Victoroos

Yes there is a key assignment for this. It's in the CDU options pages. First press disconnects the autopilot second press cancels the warning indications. As for when to disengage the answer is easy. When you are ready to take over manual control.

In reality, pilots press the AP disc button on the yoke/stick twice (once to disconnect the AP, and again to cancel the aural warning).

 

You would only force the controls or use the AP buttons on the glareshield/MCP in abnormal operations.

To answer the question when to disconnect the autopilot it depends on few things:

 

_ the company SOP (as per my understanding companies define in their procedure at which minimum altitude or height the autopilot should be disconnected)

_ if you are on an approach which allows autoland (ILS cat II or cat III) or not (all the others).

_ the weather conditions (if you have strong cross wind, you would prefer fly and land manually)

 

So if you are on a ILS cat II or III, you may go all the way to the landing with autopilot and disconnect during the roll out.

 

Otherwise, you will disconnect the autopilot at any moment you are confortable with, may it be during the descent, the approach but above the minimum altitude or height defined by your company and in any case above the MDA.

 

I usually disconnect the autopilot either during the intial approach or at latest just after established on an ILS.

 

 

-And, that is how it is done after touchdown? After the roll out is done? 

 

Disconnecting is the same in all situations: two presses.

 

 

 

-So, what I do now (just moving the controller to the left till ti disconnects) isn't right (realistic)? 

 

This is absolutely not right. In the NG, it can break the shear pin. Pressing on the controls enough to disconnect the AP has also contributed to a few crashes (in addition to pilot inattentiveness): AFL593, and EAL401. While APs now have some sort of alerting function to alert you to it dropping from active to passive modes, it's best to avoid trying to disconnect it in any other way than the most intentional: press the disconnect button twice.

 

 

 

-And will it work in the 777 (so I don't have to press the invisible click point)?

 

Yes. The 777 has the same function in real life, and we don't usually make it a habit to randomly remove functions between our aircraft offerings unless there's some reason to.

 

Notice that, in the video, one of my examples shows me clicking on a button on the yoke. The 777 has a similar button, in a similar position.

 

 

So if you are on a ILS cat II or III, you may go all the way to the landing with autopilot and disconnect during the roll out.

 

Technically, the ILS CAT for the approach being flown doesn't matter. They could be clearing visual approaches all day and I could autoland using the Runway 1R ILS at IAD if I wanted to. What matters is that your plane and the ILS at the field are appropriately certified. The 1R ILS at IAD and the 17 ILS at JYO are virtually identical. The difference between the two, though, is that the 1R ILS has gotten additional attention to ensure that signal quality is verified, interference is minimized, monitoring is constant, and power is ensured (that's a very high level list, but more in-depth is for another discussion).

Disconnecting is the same in all situations: two presses.

 

 

This is absolutely not right. In the NG, it can break the shear pin. Pressing on the controls enough to disconnect the AP has also contributed to a few crashes (in addition to pilot inattentiveness): AFL593, and EAL401. While APs now have some sort of alerting function to alert you to it dropping from active to passive modes, it's best to avoid trying to disconnect it in any other way than the most intentional: press the disconnect button twice.

 

 

Yes. The 777 has the same function in real life, and we don't usually make it a habit to randomly remove functions between our aircraft offerings unless there's some reason to.

 

Notice that, in the video, one of my examples shows me clicking on a button on the yoke. The 777 has a similar button, in a similar position.

 

 

 

Technically, the ILS CAT for the approach being flown doesn't matter. They could be clearing visual approaches all day and I could autoland using the Runway 1R ILS at IAD if I wanted to. What matters is that your plane and the ILS at the field are appropriately certified. The 1R ILS at IAD and the 17 ILS at JYO are virtually identical. The difference between the two, though, is that the 1R ILS has gotten additional attention to ensure that signal quality is verified, interference is minimized, monitoring is constant, and power is ensured (that's a very high level list, but more in-depth is for another discussion).

thanks for the answers guys! .

I meant when is best to disconnect? After rollout? Or really whenever I like to manual fly? (as in, when I'm ready).

Vkr

thanks for the answers guys! .

I meant when is best to disconnect? After rollout? Or really whenever I like to manual fly? (as in, when I'm ready).

Vkr

Whenever you're ready.

 

 

Technically, the ILS CAT for the approach being flown doesn't matter. They could be clearing visual approaches all day and I could autoland using the Runway 1R ILS at IAD if I wanted to. What matters is that your plane and the ILS at the field are appropriately certified. The 1R ILS at IAD and the 17 ILS at JYO are virtually identical. The difference between the two, though, is that the 1R ILS has gotten additional attention to ensure that signal quality is verified, interference is minimized, monitoring is constant, and power is ensured (that's a very high level list, but more in-depth is for another discussion).

 

Hi Kyle,

 

Thanks for the precision, good to know. 

However, technically you can do autoland with any ILS CAT, but legally are you allowed to perform an autoland on a ILS CAT I?

And between two ILS like at IAD and JYO, is there a mention on the charts to specify whether the ILS is specifically monitored?

 

Thanks.

However, technically you can do autoland with any ILS CAT, but legally are you allowed to perform an autoland on a ILS CAT I?

 

Depends on where you are, and how you interpret the regs.

 

The FAA makes no distinction (in the regs directly) about the CAT of the ILS:

 

FAR 121.529b

When using an instrument approach facility, no person may use an autopilot at an altitude above the terrain that is less than twice the maximum altitude loss specified in the Airplane Flight Manual for a malfunction of the autopilot under approach conditions, or less than 50 feet below the approved minimum descent altitude or DA/DH for the facility, whichever is higher, [...]

 

FAR 121.529c (more important in the case of autoland)

Notwithstanding paragraph (a) or (b) of this section, the Administrator issues operations specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic capability, in any case in which—

(1) The system does not contain any altitude loss (above zero) specified in the Airplane Flight Manual for malfunction of the autopilot with approach coupler; and

(2) He finds that the use of the system to touchdown will not otherwise affect the safety standards required by this section.

 

Note the lack of reference to ILS CAT. Essentially, as long as your aircraft and crew are certified, and it's in line with your OPSpec, then there shouldn't be an issue. From a technical standpoint, the plane has no idea what CAT it's flying. The signal is no different, in terms of how it's broadcast.

 

 

 

And between two ILS like at IAD and JYO, is there a mention on the charts to specify whether the ILS is specifically monitored?

 

It's not specifically indicated on the chart. If there is a CAT II or CAT III approach to that same runway, then the ILS meets the requirements for monitoring to the CAT III level. Additionally, the A/FD will list times when the various navaids are unmonitored:

"LOC/DME 109.1 I–BCB Chan 28 Rwy 12. LOC/DME unmonitored when arpt unatndd."

Thanks Kyle, that's clearing up my misconception of autoland in which the autoland could not be performed on CAT I.

Very instructive post.

Thanks Kyle, that's clearing up my misconception of autoland in which the autoland could not be performed on CAT I.

Very instructive post.

 

You're welcome. It's a very common misconception, which is usually why you see me get bent out of shape when people say "CAT III AUTOLAND." We really just need to start referring to it as an AUTOLAND, or at max, ILS AUTOLAND (to emphasize it only works with ILS - you wouldn't believe how many people think they can AUTOLAND on any runway).

It's worth remembering that whilst the law may not mention approach category, most operators will have restrictions on practice autolands in CATI conditions. Most will at the very least require the runway in question to be on the operator's approved list of autoland runways, which in practice means at least a certified CATII/III ILS installation.

 

All the work and disruption involved in LVPs isn't just for show -- a large amount of it is to do with safeguarding the ILS critical areas. This safeguarding is not present unless LVPs are in force, and most airports will not waste money running the backup generators etc required for the ILS in CATII/III conditions if they don't need to either.

 

So when you are conducting a practice autoland in CATI conditions, you must be aware that the integrity of the ILS signal is not guaranteed and that if there is a power failure on the ground affecting the ILS, it will almost certainly disappear. An aircraft or vehicle could also enter the ILS critical area and distort the beam (possibly at low level) and the extra final approach spacing required to ensure that the preceding aircraft does not distort the beam will not be in place either.

 

The aircraft is perfectly technically capable, but the outside conditions are not the same and you should be particularly cautious. If I remember rightly, I believe there was a Singapore B777 that went rather spectacularly off the runway in Munich after conducting an autoland in CATI conditions -- put down to a distortion of the beam at a late stage in the approach.

 

It's not quite "here be dragons", but you should definitely be aware of the threats.

 

 

most operators will have restrictions on practice airplanes in CATI conditions.

 

Thus the mention of:

"Essentially, as long as your aircraft and crew are certified, and it's in line with your OPSpec, then there shouldn't be an issue."

 

 

 

The aircraft is perfectly technically capable, but the outside conditions are not the same and you should be particularly cautious.

 

Definitely. I didn't intend to put it off like there wasn't inherent risk (which is why I added the extra high level requirements for CAT III certification, among other references).

Absolutely. I just wanted to highlight some of the potential risks that others may not be aware of (and, let's be honest, in FS it's all academic as every ILS is perfect!)

 

Incidentally, I found the text of the report in the the SQ B777 at MUC: an excellent demonstration of the threats involved.

 

"The airport was operating according to CAT I standards (no low visibility procedures in use). The aircraft was cleared for an ILS approach to runway 08R.

 

When the Boeing 777-300 was about 2.1nm before touch down a BAe Avro began its takeoff run on runway 08R. The Boeing 777 was subsequently cleared to land on runway 08R, winds from 130 degrees at 7 knots. When the Boeing 777-300 crossed the runway threshold, the Jumbolino was climbing out still short of the runway end.

 

A number of aircraft were holding before the CAT II/III hold short lines (outside the runway protected area).

 

6 seconds after the Boeing crossed the threshold the Jumbolino crossed the runway end, at the time of touchdown of the Boeing the Jumbolino was climbing out just past the runway end, 26 seconds after the Boeing crossed the threshold the Jumbolino overflew the localizer antenna in a height of 740 feet.

 

When the Boeing 777-300 descended through 30 feet AGL, the aircraft began to roll left, the left main gear touched down first about 490 meters/1610 feet past the threshold, the autopilot changed into roll out mode. The aircraft rolled towards the left edge of the runway and crossed the runway edge at about taxiway B4 1100 meters/3610 feet down the runway. At this point rudder inputs by the crew prompted the autopilot to disengage. The aircraft rolled in a slight right turn over grass for about 400 meters/1310 feet, reaching the farthest point of excursion to the left 1300 meters/4260 feet past the runway threshold, before it crossed the runway edge again onto the runway and crossed the runway at a track of 121 degrees magnetic crossing the right runway edge 1620 meters/5310 feet down the runway. The aircraft came to a stop south of the runway on grass about 60 meters off the runway and 1780 meters/5840 feet past the runway threshold...

 

...The BFU reported that the flight data recorder showed all three ILS receivers recorded localizer signal deviations in both directions about 14 seconds before the autopilot changed into roll out mode, about 6 seconds prior to the roll out mode the localizer deviation increasingly showed a deviation of the aircraft to the right of the extended center line. The aircraft began to roll left in response to autopilot inputs to minimize the localizer deviation and reached 3.5 degrees bank angle to the left when the autopilot changed to roll out."

 

 

Incidentally, I found the text of the report in the the SQ B777 at MUC: an excellent demonstration of the threats involved.

 

Yeah - that prompted me to go look it up. I don't recall having heard of it prior to you having mentioned it, so thanks!