Sign in to follow this  
Guest art

ILS Approach Problem

Recommended Posts

Hi there!I have a question concerning a minor problem I have experienced when doing an ILS approach. I am established on the glidescope in APP mode with both APs engaged and the Approach-Phase in the FMC entered.The problem is that the aircraft is always too low, quite a way under the ILS bug (horizontally there are no probs, even with light x-winds). I ususally scroll through the flap settings and appropriate approach speed reductions, extend the undercarriage at about 2000 feet. BUT I am always too low, either landing before the threshold or sometimes even on the grass (on in KSFO in the water....!)The only way to counter this is to do a manual throttle "boost" until the ILS bug is centered again, but this only helps for a few seconds and usually causes severe pitch problems as the a/c tries to "recover".This problem is also coupled with a pitch problem - the nose seems unusually high, somewehre between 10 and 15 degrees. This only occurs in all of the smaller airbusses, i.e. 319 thru 321. The bigger birds are fine.Every landing has the familiar "too low, terrain, too low terrain, pull up, pull up" commentary.....I know it backwards now and if I actually ever meet the guy who did the voice over...!!!I always use the fuel planning/load edit tool, so I don't think that this is an issue.Any ideas?Thanks in advance and regards from a sunny EDDF (29.94)Ed

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

I would check if your payload is distributed evenly; if you have entered correct ZFW and fuel on the INIT page; and if the altimeter is set.

Share this post


Link to post
Share on other sites

If I'm correct, the payload editor fills from the front right, so if anything I should be nose-heavy!ZFW and Fuel are farily correct, at least according to the two pss calculators. I usually set the altimeter at a transition altidite of 9.000 feet - but even with the perfect weather scenario and a constant barometer of 29.92 the problem still occurs. I thought about this too whch is why I tired it, but it offered no remedy.I have subsequently found some similar threads here and apparently this problem is a 319/320/321 bug and that alot of people come in looking at the sky :-))Thanks and regardsEd

Share this post


Link to post
Share on other sites

Ed,That is a known problem with some people, like myself and even Rob Elliot who is one of the PSS support members.Apparently it's not everybody's problem, and PSS has no clue (at least they haven't come forward with an answer in previous posts about this issue), so I went around it using selected speed and increasing the VAPP by 5 Kts. It doesn't cure it, but at least you're not that far below Glideslope.Let us know if it helped.CheersJo

Share this post


Link to post
Share on other sites

I'd like to try it. Could you upload the saved flight and saved route?

Share this post


Link to post
Share on other sites

In common with quite a few pilots, throughout the life of the Airbus A320 family under FS9/9.1 I have had the "glideslope, glideslope" aural warning on most approaches where the aircraft should be holding the glideslope. (I would prefer "too sober, wine" but a patch for this hasn't issued yet). The glideslope deviation indicator usually hovers around half a dot above the centre. I get the warning even though the approach is fully stabilised and everything is normal. I have tended to just ignore or switch off the warning, and as I usually fly short finals manually anyway it hasn't been any more than a minor irritant.But one very curious thing I have noticed over the last month is that if I have the cockpit zoom set to 0.5 - something I now prefer - I don't seem to get the warning. There can be no logical reason for this that I can think of and you will probably think I'm talking rubbish, but for the last few flights it has certainly improved things. It is an interesting if curious potential solution. I really doubt the zoom level should have any effect but it does seem to. Once I am back from my course and exams at the weekend I'll try it again and report back but you might want to give it a go.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

Share this post


Link to post
Share on other sites

>I'd like to try it. Could you upload the saved flight and>saved route?vrapp - hi there! This is a problem that occurs with almost every flight and it is not restricted to a particular route, airport or approach even. The worst case though has been on a flight from EDDF (Frankfurt) to EGLL (Heathrow) using the LAM approach into runway 27R. Blokk fuel was low anyway, as its only a short hop of an hour and we had no deviation to our altrnative destination of Gatwick. There were relatively few passengers due to the time of day and even less cargo. The weather was anything other than inclement and there was no cross wind - so basically an easy-peasy approach and landing in a virtually empty, light aircraft. At about 4 miles out, over the middle marker, and still in APP mode I had a positive pitch of about 17 degrees...switching to manual ode only made 4 degress of difference, but I got it down to 13 all the same.But it was a lovely sunny day and the sky over Middlesex looked amazing.....some consolation :-)Anyway, thanks everyone for your replies - I will try the maginifacation setting of 0.5 as Rob suggested. At face value it does sound a pretty wacky diagnosis, but if it helps!!Regards from EDDFEd

Share this post


Link to post
Share on other sites

What I suggested is not designed to correct the nose up attitude on approach (something I have never had since using the adjusted lift scalar figures). It was only there for the problem of the aircraft being slightly below the glideslope leading to the "glideslope" warning.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

Share this post


Link to post
Share on other sites

I'm also having a trouble with the ILS approach it's happened 3 times today with the A320 (didn't try with the other).When my plane is a 3 miles from the runway the nose isn't pick up but down and my plane crash everytimes... I tried to reinstall it but nothing change...If anyone has an idea about that...

Share this post


Link to post
Share on other sites
Sign in to follow this