Aircraft questions

[Chris_F]

Hey all, got a question.

I've downloaded Moach's "The 737 Experience", a really nice freeware 737-700 available on this site.  I love the plane, I've made the flight model update.  Didn't update the panel since I like the original better.

Okay, here's the problem:  The plane can't fly autopilot approaches.  When I engage the approach hold the plane makes a Kamakazi dive to the ground when it intercepts the beam.

I figured: no problem, I'll just replace the physics and AP with those from the default 737-400.  Okay, that wasn't as easy as it seemed.  I started by replacing most of the 737-700 aircraft.cfg with the default 737-400.  After learing all sorts of neat stuff about the [fltsim.x] sections of the aircraft.cfg I got it to work but now the plane wouldn't fly.  It just fell out of the air like a brick.

That got me to wondering: what does the Boeing737-400.air file do?

Ideally I'd like to fix the approach hold in the 737-700.  Failing that I'd like to replace its flight dynamics with those from the 737-400.  Along the way I suspect I'll learn a ton of neat stuff.

[Papa9571]

I have the same aircraft and had the same problem.

Actually the problem is not with the aircraft, the problem is the pilot.

I could take off, place the navigation mode switch to the GPS position, fly my route, follow all ATC vectors to final, then when I hit the approach button all hell would break loose.

[KDSM]

Quite true

the nav/gps button tells the autopilot where to take its flight control instructions from

NAV=NAV RADIOS
GPS= THE GPS

and since the ils is a radio it should be set to nav

tank you vurrry much ....elvis has left the building

[Chris_F]

Thanks for the replies so far, I'll double check the switches.  I'd be suprised to find I was flying GPS though as I always fly in NAV.  Perhaps it defaults to GPS and I'm just not used to it?  Like I said, I'll fly it again in NAV and see what happens.

[simonmd]

Don't forget that you must always intercept the ILS beam from below as well.

[Chris_F]

I tried flying the approach again.  Autopilot defaults to NAV and I've never taken it off of NAV so it's unlikely that I flew these approaches with GPS.  Besides, runway alignment has never been the problem.  Keeping on glide path is the problem.

As for approaching the beam from below, that's how I do it.  I've done perhaps hundreds of approaches in the default planes, many of these in the 737-400 on autopilot without a problem.

Anyway, I didn't die this time, the plane instead flew over the glide scope, WAAAYYY too high.  Too high is better than too low, but failing to follow the glide slope isn't confidence inspiring.  I'm sure it's just random whether or not it errors on the high or low side of the glide scope.  (The plane is still lined up dead nuts to the center of the runway so GPS/NAV setting isn't the problem)

I still want to substitute the default 737-400 flight dynamics and AP for the 737-700.

Again, what does that .air file do?  Any pointers on getting this to work?

If anyone wants to try and replicate I'm doing an ILS autopilot approach to KMHT runway 36 in clear weather.