hello everyone!!I have been using pic for a while now, and I think I need some information...On the ground, my RA indicates -6 ft,which causes the autopilot to flare and set thrust to idle a bit too early/high during autoland.Result: everything goes well untill 0 ft RA on the eadi,where the plane levels off for a while,and as speed decreases, goes through the remaining 6 feet a bit SUDDENLY.Nothing really worrying actually, but the autoland would be perfect if everything started.... 6 ft higher !!So my question is: is there a way to bring up the "ground reference RA" to zero?Thanks a lot...

There is a solution to this- Do what the real pilots do when landing, turn off auto land some miles out and hand fly that baby in!What is the fun if we let the sim do it for us? Just my two pence................. Best Wishes, Randy

The -6ft has been discussed several times before. It is correct in that in landing attitude (nose up a few degrees) the RA is set to read 0 when the main gear touches down. Once the nosewheel comes down the RA goes negative. I believe the RA sensor is somewhere near the front gear.Lee Hetherington (KBED)

> I believe the RA sensor is somewhere near the front gear.http://members.ozemail.com.au/~b744er/767/RAAntennae.gif;-)There are 3 RA systems for redundancy. Each system has a transmit and a receive antenna. The Captain's displays show the Left RA System, the F/O's, the Right RA System. Both can select the Center RA System with Instrument Switching.The RA systems provide Rad Alt data to many other airplane systems including the Autopilot, GPWS, TCAS and Landing Config Warning Module (but I haven't yet figured out why the RA system feeds into the Fuel(!) System on our latest 747-400's).Hope this helps.Cheers.Ian.

A quick trig shows that the RA is about 86 ft in front of the main gear. I was assuming an attitude of +4 degree at touchdown, however

> A quick trig shows that the RA is about 86 ft in front of the main gear.I think you might be a l-i-t-t-l-e bit out there, Preston :-)If you look at the diagram below...http://members.ozemail.com.au/~b744er/767/Towing1.gif... you will see that the nosewheel (!) is about 86 feet forward of the main gear.My Boeing "Station" diagrams have the antennae at about Sta. 600 and the gear at about Sta. 950 (each station = 1 inch).950 minus 600 is 350" (29 feet). However, the Sta numbers are modified on the 767-300 because of the insertion of an extra fuselage section (compared to a 767-200). The extra fuselage section is about 10' long (give or take an inch), so, if I'm reading the diagrams correctly, the distance between the gear and the antennae is roughly 39 feet. Looks like you were out by a factor of 2 (Perhaps you weren't allowing for strut extension and bogey tilt... or your flare angle is too much?)Cheers.Ian.

shoot, you're right, I forgot about the hanging bogey and strut extension. I was thinking of RA=0 when main gears are firmly on the ground (struts compressed), and with nose up of 4 degrees. I figured that RA= -6 comes up when the nose gear touched down, so I punched in 6/tan 4 which came out 86. I didn't know the bogey and struts at full length change the numbers by 2x!(edit: another cool diagram btw!)

I was surprised by this -6ft reading on the ground cause I thought the RA sensors were right behind the main landing gear(like the A320 for instance)...But this explains everything.Thank ye for help!..And happy landings...even manual landings Randy!;) catIIIdual (LFPG)

Once more, PIC continues to dazzle with its subtle perfectionistic traits ;-)

But where is the RA antenna on Flightsim 767?I searched about RA antenna position on airfile, found nothing. Static or pitot port positions are not modelled in air file.I think pitot tubes, static ports and RA Antenna is all coupled to ZFW COG position. This means it's much more close to main gear than nose gear. So we are reading 6ft high.It's also becoming a problem with manual landings.In DF737, I Flare about 30ft and cut the throttle just about 10ft call. It works perfect (RA reading on EADI is 0). But in 767, it takes much more time to touchdown after 10ft call. You can easly eat 2000feet rwy on flare. I've an idea for reseting RA reading to 0 feet. It will need a lot of modifications on air file.First, let's say zfw cog is 10ft. Reducing it to 4ft and adding 6ft to contact and view points may solve the problem. We're just chagen aircrafts body height, nothing else. May be Light need improvement too.hummm.. I'll give it a go..Later..Bozhan

Have a look at this shot here...http://www.airliners.net/open.file/128428/L/It's a little blurry, but it appears to me the RA reading on this bird (on the ground) is -4 or -6. If this is how it really is, why change it?

I've a second new idea now.I'll change the referance datum point to about 26 feet forward and zfw cog to -26 feet from datum.hummm let's try this too.I'll inform you tomorrow.And riddlepilot, we are 767 gurus, are you? Please read the entire post againg.

And then you'll screw up everything for no good reason. You'll screw up the locations of the wings, stabilizers, control surfaces, engines, landing gear, etc. The reference datum point is the reference for everything!Lee Hetherington (KBED)

Travis,Don't respond to this! Let me do that please.Lee,Your waisting your time.Bozhan,You can can say these kind of things if you want because this is an open forum. "And riddlepilot, we are 767 gurus, are you? Please read the entire post againg."You can tweak settings however you want cause you are a guru, it's your computer, and it's your PIC product.But you can't expect to get any further replies from normal reasonable people if you project an errogant attitude like that. So respond here if you want, but like I said, don't expect a reply because there will be none.

The -6 is the correct reading, as in the real aircraft .In the flare you should be at 0 RA when the mains touch at an approximate 6 degree nose up pitch. If your floating on the flare your speed is to high, I have never had a problem with this on autolands ,it hits the marks everytime on a cat 3 designated runway. On our 737NG's the RA is -4 static for instance. Changing anything in the airfile or cfg file will only make your 767 an incorrect simulation. They have done there homework on this and there's no need to change it.