"HELP! Keep landing in water. Need Approach Hold help in Boeing."

[MBison]

Okay, here's the situation.

I'm in a Boeing 737-400. I want to fly an autopilot Approach Hold landing into KSFO but I keep landing in the water.

I'm about 1,800 feet around 20 miles out. I got the glideslope on my HSI. I press the APR button with autopilot armed. And I always plummet into the sea.

Is there a trick to using the APR button?

Do I disable all other autopilot switches (heading, altitude, IAS) before pressing APR? When should I press APR for the first time? Should autopilot do all of the work in Approach Hold mode?

Please help me someone!

In a similar question, can you provide quick tips on flying this in manually? I understand I must line up the purple "runway" into the centerline by making small heading adjustments. Once centered, how do I know if I'm the right altitude? Do I just start descenting and the purple indicator on the side of the HSI lowers appropriately?

Aigh!

Thanks very much!

Bison

[N757QQ]

Heya...

If you are not on the glide, you need to keep the ALT hold on, APR will auto turn off the ALT hold when it gets on the glide. Also, for being 20 miles out, 1,800 is a bit low, but thats not an issue here.

As far as flying manual approaches, you really need to fly it in calm winds, during the day, with an aircraft you are used to. Once you know all the little quirks about the approach, like it staying left until you get on very short final, etc. Or the glide being a bit off (some are like that in FS). Once you are familiar with it, you can close up the vis to about 3-5sm, & turn up a bit of a crosswind, or whatever you want, & try it then.

That way, you concentrate on the gauges, & not on where the runway is. Once you get visual on the runway, take it on in with visual aids, & still scanning those gauges to make sure you are right on by the localizer & glide.

Then you can work on others, but manual approaches are difficult if you are in low vis. Not to mention the over sensitivity of some localizers on very short final.


This is not the greatest rundown, but a short & dirty one.


Enjoy

[Heber98]

A few things..

First and foremost you have to remove some fuel.
Aircraft menu, Fuel.. set maybe 20% or so.

You don't have to disable anything in the autopilot for APR Hold. Normally I set altitude and heading hold to set up for the ILS. Then as the radios receive the localizer I set APR hold. HDG will automatically go off but ALT hold will remain on until you are dead on the glideslope.

Other than that just make sure your speed is realistic and you are setting flaps and gear. Press ctrl+/ to set the autospoilers.

Disarm the autopilot at 200ft and raise the nose ever so slightly to decrease rate of descent. When the mains are down hold F2 for reverse thrust.

[mdklatt]

>First and foremost you have to
>remove some fuel.

Or, more realistically, use the correct approach speed for your current weight. If the plane drops like a rock you're in the wrong configuration. Use more flaps and/or a higher approach speed.

[kaiallard]

[font color=#333366]
its not necessary to congigure fuel
if you have more fuel, land at a faster speed... thats all... my flaps are usualy at 30 for all situations

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[tgibson]

This is not true. With too large a fuel load you can easily be over Maximum Landing Weight, and you will not have a realistic landing (you will have to fly too fast). Thus fuel does matter.

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[mdklatt]

[font size="1" color="#FF0000"]LAST EDITED ON Jun-03-03 AT 02:26PM (EDT)[/font][p]>This is not true. With
>too large a fuel load
>you can easily be over
>Maximum Landing Weight, and you
>will not have a realistic
>landing (you will have to
>fly too fast). Thus
>fuel does matter.
>

...just not to the extent that some people think.

[palmpilot]

"I'm about 1,800 feet around 20 miles out. I got the glideslope on my HSI. I press the APR button with autopilot armed. And I always plummet into the sea.

Is there a trick to using the APR button? " Yes. and NO!

There's more to it than having a/p on and hitting apr button!

You don't say, but do you (as has been pointed out) approach with a/p on, alt set and heading set? If not then that is what you are doing wrong. These must be set.
and yes, 1800' is too low at 20mls out. Try 4000' at that distance.
Line up with the correct runway heading and press apr. If you are on the money the hdg light will go out and apr will steer the plane. When the glide slope is reached ( yes, you should approach on a level flight under the slope to catch it better) then the alt light will go out and the plane will start down the slope - or should do.... If not, you've cocked up somehow, altho' apparently 02 is tetchy in this respect. I'm still using 2000. pp