After doing an approach to Beirut's runway 17 using an Air France 747-400, I realized that the PAPI isn't accurate.Here's why.The four screenshots below were taken the same time when I had the flight paused.As you can see, I took these shots at different angles. As you move up and down, the PAPI changes.Take a look for yourself.At this angle, it tells me I'm perfect:http://forums.avsim.net/user_files/40032.jpgHere it tells me I'm a little high:http://forums.avsim.net/user_files/40033.jpgHere it tells me I'm too high:http://forums.avsim.net/user_files/40034.jpgHere it tells me I'm too low:http://forums.avsim.net/user_files/40035.jpgWhen I was in the cockpit however, the PAPI told me I was just right:http://forums.avsim.net/user_files/40036.jpgBasically, the PAPI is only accurate from within the cockpit. If you're in the outside view, it will change depending on the angle. It seems to determine how accurate you are based on the camera position and not the aircraft position. Kinda disappointing, but oh well. Can't have everything.That's why in screenshots of approaches to Beirut, the PAPI is telling me either I'm too high or too low.At first, I thought the PAPI just doesn't function properly at all. But it turns out it does, but only from within the cockpit.Regards

Hi,Actually, this is quite realistic! That is how an approach slope/path indicator works. It all depends on the angle based on your eye position. If you were in a chase plane in real life following such an approach, you would get the exact same effect. Don't see any problem here!-Damian

I would second that this is very accurate.In the shots you provided-the lights are reacting to your height above or below the aircraft. Since your aircraft is on the glidepath-going above your aircraft will show you too high, and going below it will show you too low-which is what your shots show.If we were able to actually slide out of a real aircraft and do what you did in your shots in reality-that is what would actually happen.More game like would be lights that would remain stationary in your scenerio-no matter your height.http://mywebpages.comcast.net/geofa/pages/Geofdog2.jpg

Hi there,>But it turns out it does, but only from within the cockpit.http://hifi.avsim.net/activesky/images/wxrebeta.jpg

If you were in a chase plane in real life following such an approachThe point is you are not in a chase plane. You are simply looking at your own aircraft from different angles.That's why the PAPI should not be changing.If I was in a chase plane following this 747, then that would be different, but I'm not.I simply paused the game, got to the external view and looking at my OWN aircraft that I am flying. That's why the PAPI shouldn't be changing.

Actually-if you look at the fs menu-it is called "spot plane view".You are in a "virtual" spot (chase) plane-who's angle and distance is changed by you.http://mywebpages.comcast.net/geofa/pages/Geofdog2.jpg

>Actually-if you look at the fs menu-it is called "spot plane>view".>>You are in a "virtual" spot (chase) plane-who's angle and>distance is changed by you.>>http://mywebpages.comcast.net/geofa/pages/Geofdog2.jpgThey may call it a spotplane view, but I don't consider it to be a spotplane because you aren't actually inside a spot plane and can't control it except moving around the plane you are chasing.I consider it to be a "hovering imaginary camera."We all have different opinions. This is just my opinion on this issue.

I consider it to be a "hovering imaginary camera."Looking at the PAPI through this imaginary camera of yours, the indications would be exactly as per your screenshots, so why do you insist they are wrong?Stamatis

"We all have different opinions. This is just my opinion on this issue"Unfortunately, your opinions are wrong.Other posts have described in detail how PAPIs work, I agree with them, they are perfectly accurate.

Yes, the PAPI lights work just fine. Doesn't matter if you look at them from a spot plane, an imaginary camera or a bathtub, the lights will continue changing as long as you position yourself at different angles from them, inside or outside your cockpit.However, I have noticed that on some airports the PAPI lights don't agree with the glideslope. Once the GS indicator is centered you should be seeing two white and two red PAPI lights. This doesn't happen at SKCL, SKRG and SKCC. If you focus on 2 reds and 2 whites you will get the dreaded "glideslope" warning on final. On the other hand, if you go with the glideslope you have four whites all the way (and often overshoot the runway).Any ideas why this is so? Mauricio

>I simply paused the game, got to the external view and looking>at my OWN aircraft that I am flying. And therein lies the misconception. You are not looking at just your "OWN aircraft" from differnt angles, you are looking at the WHOLE SCENE from different angles. Notice how the airport buildings in the background change in relation to to the framing of the picture.R-

EDIT: double post

>And therein lies the misconception. You are not looking at>just your "OWN aircraft" from differnt angles, you are looking>at the WHOLE SCENE from different angles. Notice how the>airport buildings in the background change in relation to to>the framing of the picture.>>R-That's true,the background does change since you are moving. But tell me, what is the only object you can move around in the external view? You can only move around your own plane.Of course when you change angles, the background will change. It's got to.

>Unfortunately, your opinions are wrong.>>Other posts have described in detail how PAPIs work, I agree>with them, they are perfectly accurate.JDH, please don't use that attitude. There is no need to start being impolite and rude. I have been debating my point in a kind manner, and am treating all other members with respect. In return, I expect to be treated with the same respect.There is no such thing as a wrong opinion.I was not arguing how PAPI works, I know how they work. I was arguing the fact that the PAPI stops following the aircraft on approach when one is in the external view.Let us say that the external view in reality really is a spotplane. Let's say this was a real situation.Let's say there is an Air France 747-400 about to land at night in Beirut's runway 17 and there is a spot plane next to it or behind it. Will the PAPI be following the 747 which is the aircraft about to land, or the spot plane simply flying next to it "spotting" it?You will answer that it will follow the 747, since it is the aircraft directly infront of the runway about to land, not the spot plane which will be landing later on after it makes a go-around or something.Also another reason why the PAPI isn't accurate. If you are flying at 35,000ft. over an airport with PAPI, the PAPI will start following that plane that is 35,000ft. high.What's also interesting is when you are landing at an airport that has 2 parallel runways each with PAPI, or 2 almost parallel runways, both PAPIs will follow that same plane which is obviously on approach to only one of the runways, not two.Also, when you are taking-off and climbing, the PAPI that is behind you starts to follow the aircraft which simply just took off and is not landing.If you believe the PAPI should follow the eyepoint, that's fine by me. I don't, I believe the PAPI should only follow the aircraft about to land just like in real life and that is simply my own opinion.Again, all I ask is some courtesy just like I treat you and everyone else with courtesy.I have no problem debating or arguing a point as long as it remains in a civilized manner.

>I consider it to be a "hovering imaginary camera.">>Looking at the PAPI through this imaginary camera of yours,>the indications would be exactly as per your screenshots, so>why do you insist they are wrong?>>Stamatis>Because the PAPI should follow the aircraft only and not the imaginary camera. The aircraft is the one on approach to the runway not the imaginary camera or if you want to call it a spot plane.