Why did the Autopilot Approach do this? Why?!

[Retro]

I was following the FlightSim Veteran's Club guide to using the FS2K2 autopilot (flying a 777 as well), and everything was going fairly well. I was doing a short hop from KAUS to KDFW (landing at 36L), with IFR. I followed ATC's vectoring, and soon found out that having it direct you straight in leads to your aircraft being a few thousand feet above the runway; I expected a problem like this from the FSV's guide. So, I declared a missed approach, was handed off numerous times to several DFW Approach centers, and followed their vectors to circle the airport. I was happily moved to a little more than 20 miles Southwest of runway 36L; according to the FSV's guide, a great place to hit that "Approach" button. I made sure that my NAV1 was tuned to the 36L ILS a long while beforehand; in addition, the glideslope diamond had appeared. Again, I'm following the FSV guide (this is my first time flying an approach by autopilot. Ouch.) - so I think things are happy-happy.

This time, the Approach function starts making all the correct turns just as ATC is calling them out. As expected, the HDG light first turns off. I can tell that the Autopilot Approach is turning me towards the runway. A few moments later, and the ALT light goes out. All as expected from what I read in the FSV's guide. Like the guide's writer clearly stated, I made sure just to hit the APR function do its thing (as in, no hitting other autopilot buttons).

Hey, for a first-timer like me, things are actually going well. I am clearly aligned with the runway. There's a 737 on its final in front of me, although I'm noticing it seems a bit...higher than me. I have also made SURE to reset my altimeter by hitting the B key all throughout the flight.

There's one small problem: It appears the Approach function would like to bring me down a few miles out from the runway. I have made sure that I have mashed the "B" key several thousand times. Whee! I'm perfectly aligned with the runway, thanks to the Autopilot Approach function, but I land right into a building. Building Crash!

I am just...stumped. Why on earth did it do that? Why on earth didn't the APR function make ANY changes in throttle or pitch to avoid doing a ten-point-landing into a building, a good five miles away from 36L?

Sigh. I've spent all night reading that guide, playing around with the autopilot "features", and I thought I could do a simple Autopilot Approach to DFW. I ask of those of you who are more experienced: What happened? Why did the APR function DO that? And when exactly should you engage the APR function?

And for the love of practicality, is there SOME freeware something-or-other that disables Cessnas, Cherokees, and all those Itty-Bitty planes from landing at large, metropolitan airports? Sometimes, I can't even get a word in due to all their ATC chatter.

[dil52]

You did eveything by the book and congradulations for doing the RFM thing. You should be commended. :-)

Check your IAS (light should be on) and mimimum speed. I'd say not to go below 140-150kts depending on amount of fuel you have (weight).
APR alone will not control your speed. Also make sure you are increaseing you flaps settings as you decrease speed.

quickly these are approximate.
1 degrees 220-200
5 degrees 180-200
10 degrees 170-180
15 degrees 165-170
20 degrees 150-165
(gear down)
30 degrees 140-150

This dosen't have to be precise, wind conditions can make a big difference. You will see in time.

You should do a quick review of them the miniums for flap settings though. I'm just doing a quick response here.

All the Best, :-)
Fred
http://www.flight-sim.net

[CRO200]

true. Speed needs to be properly set. I change my speed often in the approach as i follow the glideslope needle. I havent managed to land the 777 using 140kts but i suspect thats becuase im using unlimited fuel, therefore my aircraft is heavier.

[dil52]

C
Once you get within 500' or so, disable your autopilot,then 'bump' the yoke (or joystick) and throttle to make sure you are in control, and fly it in by hand.
Your first tendency will be to slow down too much. Don't be afraid to keep your speed up, using your hand throttle, until just before touch down. After a few tries you'll know just where to preset the throttle that it will be close to where you want it once you dump the autopilot.
When you get good at landing with full fuel, landing with minimum fuel with be a breeze.

Hope this will help a bit.:-)
Fred
http://www.flight-sim.net

[Slartyfartfast]

[font size="1" color="#FF0000"]LAST EDITED ON Jan-19-02 AT 03:27AM (EDT)[/font][p][font size="1" color="#FF0000"]LAST EDITED ON Jan-19-02 AT 03:23 AM (EDT)[/font]

As I approach the ILS I normally reduce my speed to 200kts, as I get closer to it I reduce it to 180kts, as I turn onto the ILS I reduce it to 150kts, then once I am established I reduce it to 140kts, then take the plane all the way in at that.
I have the autothrottle and autpilot engage/disengage set up as buttons on my joystick, over the inner marker disengage autopilot (IAS will stay lit) and hold the profile, as I approach the threshold of the runway disengage autothrottle, reduce to idle. Ease back on the stick for flare and there you have it. Perfect landing every time. Hit the reversers, autobrake comes on, autoarmed spoilers deployed.

Please leave the runway by the nearest exit!!

Happy Landings,

Slartyfartfast:D

PS.I am unsure about this for FS2K2 but I am sure in FS98, when you had unlimited fuel set, the fuel level still reduced to 0 and when you hit empty you just kept flying. I can't be sure as it is that long since I used FS98. If this is true you may not need to tweak the speeds for landing with full fuel.

[TCLeics]

Did you activate the 'Autothrottle' switch next to the A/P switch?

Tony

[dil52]

I don't mean to disagree, because that's exactly how I used to fly approaches. That's good at first. In fact that's by the book according to MS. I guess i started doing it that way because of the ATP instruction flights.

Then I read DF's 737-400 real world pilot's description of making an approach and landing. I concluded that the airport management and the ATCs were pulling their hair waiting for me to land....just too slow :-)
Elmar's fantastic description went something like this.
Vectored to the localizer at about 180 and 10nm or less from the runway.
At 5nm out he reduces to speed to 160 and sets in 15 degrees of flap. (It seemed at first I was too clean too close.) :-eek

This is when he sets gear, autobrake and arms the speed brake.

Once he captures the glide slope he reduces speed to 150kts and applies 25 flaps.
At 400' he turns off the autopilot, maintains 700'/min decent and doesn't cut throttles and flare until 50'.

That's a lot of things happpening in a short period of time. :-)
I've since read other pilot's descriptions and they all seem to agree. In busy airports, they don't have time to wait while you slowly glide in at 140kts from 15-20 miles out.

The idea of not pulling back the throttle until the last moment, also leaves the Go-Around envelope open until the last possible seconds.

Seems to make sense now, but I'd encourage newer simmers to take it slow and easy at first. It takes many hours and approaches until it becomes 2nd nature to set all the checks in such a short time. Especially when you're the only one doing it all and he has the assistance of a 2nd officer. :-)

For some great reading check this site out. http://www.b737.org.uk/articles.htm

Enjoy,
Fred
http://www.flight-sim.net

[damodee]

Hi
I to read that page and I can tell you now you have to set the flaps to the correct setting.
I didnt and every time, I crashed well before the airport.
Its the flaps!

Damo

[Slartyfartfast]

I only go to 140kts when I am within 4 miles fo the airport, it's not that far to glide in.

Slartyfartfast:D

[Welshy]

Hi,
I was wondering if anyone can tell me what is the sfaest speed to land a heavy like a 767 or A330 airbus with the ILS?I have been landing at 250 knots,but when I apply the reverse thrust and turn off the autothrottle,the heavier jets do not pull up before they get to the other end of the runway.