Archived

This topic is now archived and is closed to further replies.

patrickbc

Descent problem.....Again :-(

Recommended Posts

Hey I have flown multiple times with the NGX but i always find it hard to descent right. Last time i flew i wrote down some thing. Please help me. ---------------------------------------- REPORT START ----------------------------------------EKCH - EHAM // SID: TOBIS3A / / Runway: 04R // STAR: EELDE1A // Runway: 22 // CRZ ALT: FL350After i did the CDU, the legs page lokked like this:(1700) 165 / 1700CH361 250 / 3522CH362 250 / FL068CH363 275 / FL103TOBIS 299 / FL244LANGO .777 / FL301ALASA .777 / FL350LISBU .777 / FL350DEGUL .777 / FL350GOLEN .777 / FL350KUBAT 259 / FL240EEL 259 / FL202NOVEN 259 / FL108ARTIP 250 / FL070 FL100Here there was a (VECTORS) but i deleted it (I flew OFFLINE)EH649 202 / 3000EH650 172 / 3000RW22 - - - / 49(386) - - - / 386(2000) - - - / 2000After 2 min. i got "Unable 250 knots at ARTIP"I continued, and after takeoff i flew direct TOBISARTIP ion the LEGS page, changed to: 250 / FL070 FL100I continuede and i began my descent at T/DAt 16000 feet i got the first : DRAG REQUIREDAt 14000 feet, Was Drag not required any more.At 11700 feet: DRAG REQUIREDAt 10060 feet, Was Drag not required any more.At 8700 fod: DRAG REQUIREDAnd now i was tired of putting Speedbrakes, up and down and.......So i let them stay up.Between ARTIP og EH649 was DECEL point, And then it went wrong.The airplane lifted it's nose (to slow down) and that resulted in the aircraft captured the Glideslope in 4650 fod, and with 200 knob.At 1800 feet, the airspeed was right so i lowered the speedbrakes.I coudn't lower the speed so much to put the sppedbrakes down on the green arrow (On the speed indicator) I had to lower them at their max speed (As i could reed under the gear leveler)But after 1700 feet, all thing was right, and i landed very nice.--------------------------------------------------REPORT FINISHED------------------------------------------------ I have 2 more questions: 1: When i have a STAR with a VECTOR in, how do i den get enabled the DECEL point. 2: What is a TRANSITION actually.

Share this post


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

I believe that a transition is just that, a transition from the star to an approach fix.Stars are standard arrivals so think of a funnel effect, multiple inbound routes to a common end point ( typically the star name fix).Once at the star fix or vor, you need to get to the approach fix to continue the approach. This is what the transition is, a route from the star to the approach fix. ATC will usually tell you this info anyway but if you fly without ATC in the sim then you will need a transition.Hope this helps a bitHope I'm right actually?Dan.

Share this post


Link to post
Share on other sites
I believe that a transition is just that, a transition from the star to an approach fix.Stars are standard arrivals so think of a funnel effect, multiple inbound routes to a common end point ( typically the star name fix).Once at the star fix or vor, you need to get to the approach fix to continue the approach. This is what the transition is, a route from the star to the approach fix. ATC will usually tell you this info anyway but if you fly without ATC in the sim then you will need a transition. Hope this helps a bit Hope I'm right actually? Dan.
Pretty much, although there isn't always a published transition. If you're under ATC control, they'll give you vectors/altitudes/speeds to fly, which is what the VECTORS bit is all about. If you just delete it from the FMS, you might shorten the route and not give yourself enough time to decend/slow down.

Share this post


Link to post
Share on other sites

It also illustrates why being 'ahead of the aeroplane' is so important and why staying glued to the FMC isn't always the brightest idea. The 'three in one' rule works for a reason.

Share this post


Link to post
Share on other sites

The EEL1A arrival ends at ARTIP. If you load the ILS22 approach there should be an "ARTIP" transition, which would be your best bet in this case (you may need to remove a VECTORS line and a redundant ARTIP waypoint from the LEGS page). This will allow you to stay in VNAV all the way down until you intercept the localizer. If there is no transition that matches up with your approach, you can vector yourself around the airport in heading select mode. Get close to the airport, then fly outbound on a course parallel to the runway in the opposite direction (i.e. on a heading of 42 degrees in this case, since the inbound course to the runway is 222 degrees). Use the distance you need to get slowed down to flaps 5 maneouvering speed at a reasonable altitude, then turn back toward the airport. You can also load the approach without a STAR, then delete the discontinuity on the LEGS page between the last point in your flight plan and the approach. That may or may not work out depending on the angle to the intercept course that you arrive at.

Share this post


Link to post
Share on other sites

Hey okay. Can that be why i captured the glideslope in 4700 feet (Bad slow down) because i didn't selected a transition.

Share this post


Link to post
Share on other sites
Hey okay. Can that be why i captured the glideslope in 4700 feet (Bad slow down) because i didn't selected a transition.
No, you can capture the glisescope many miles from the airport, typically though you might be in level flight at a set altitude before you capture.For example a normal approach would be around 3000 ft at 10 miles.

Share this post


Link to post
Share on other sites

Yeah i know. I mean. Can that be why i flew at 4700 feet when i should fly at 3000 (Bad slow down) because i didn't selected a transition.

Share this post


Link to post
Share on other sites

Yeah could be, like mentioned above, you can select your own vectors to give you room to manoeuvre before lining up for an approach.For example, landing at EGLL ( London heathrow) I often use a biggin star (3b), the minimum alt you can leave biggin is 7000 feet. If for some reason I miss out the biggin transition and go straight to the final app fix would be way too high. The biggin transition is a series of descending turns at 180 kts to line up with the approach at 7-10 miles.Dan.

Share this post


Link to post
Share on other sites

You get unable 250 because in the descent VNAV page you have a restriction 240/10000 by default. Go and change that to 250/10000.The VNAV is calculating a monotonic path for descent. Which means when you descend your altitudes and speed restrictions must get lower. What you're telling the FMC is I want to cross 10000/240 and then below that you ask it to accelerate to 250. Something else you could do is to put 250B/ instead of 250/ for ARTIP. Also if you're flying with WX make sure you insert the correct values in the descent forecast page especially if you're flying with a tailwind component. A tailwind component could give you a TOD +10nm prior to the TOD you would get with no winds aloft.

Share this post


Link to post
Share on other sites