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Snowfalcon

RC Wierdness

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Just did a long flight from YSSY to SCCI in PMDG 747First RC cleared me for takeoff after position and hold. to my horror as I accellerated down the runway a AI taxied right across the runway too late crash.Next after a reset on approach to SCCI I was told to descent from FL170 to FL110 and slow to 250kts. I did so and rechecked the altimeter. At that point I started getting continuos "Maintain FL110" calls and got a Busted altitude warning when I reached about FL114. I kept checking the altimeter and it was set correctly. Next I was vectored over the airfield and off to nowhere still getting the "maintain FL110" call from ATC. Finally I cancelled the IFR and flew the approach and landed with no problem.

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I was told to descent from FL170 to FL110... I did so and rechecked the altimeter. At that point I started getting continuos "Maintain FL110" calls and got a Busted altitude warning when I reached about FL114. I kept checking the altimeter and it was set correctly. Despite your assertion that your altimeter was correctly set, I'm afraid this has all the hallmarks of an incorrectly altimeter. If your clearance was to FL110 then you should have had 1013.2 hPa (29.92 in/Hg) on the subscale. Just what was your altimeter set to?

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hi!i had something similar to both of these situations happen recently. smashed right into a guy who decided it would be cool to taxi across 28R out of KSFO right after i had been cleared and throttled up :) it is the only time i had seen that so i figured it was a fluke. i think it was related to having a preferred RW in my flightplan, i noticed that i told to use a different one than the AI was using, and sometimes i forget to set that flag in fsbuild..but the reason i came to the forum tonight is that i had a similar issue like yours with being cleared to 11000. i was down to 11000, had auto-reply on, otto left for weather and came back and everything seemed cool. when i crossed my fix at 40 from the airport, i got a warning about missing the crossing restriction, then vectored off to who knows where. i have crossed just like this many times without any odd behavior so i'm not sure what i did differently... after i was about 80 miles from the airport and still no new vector i decided that something was amiss so i set from 1013 to 1005 which was what was reported on the weather check, thinking that somehow i missed the altimeter call (note that at this time atc had not given me a new baro reading and i was still at 1013.) it was an airport in myanmar and i usually fly in the usa so i figured maybe i missed something since the non-usa clearances and transitions still mess me up sometimes.. but i basically burned about 6k lbs of fuel heading away from the airport and flying up and down around 10.5-11.5 seeing if i could get them to realize that i had been at the correct altitude for like 15 minutes... at this point i was in some trouble, i finally declared min fuel and atc decided that maybe it would be cool if i headed towards the airport. (by now i was almost 100miles away.) i flied direct as instructed but they still refused to clear me below 11000, it's almost like it just wouldn't recognize the altitude. i got within localizer range of the airfield and was still at 11k and way above the glideslope, so i decided to ignore them and start flying down just to see what would happen. once i broke around 8k i finally got cleared to 5000, and vectored away again.. anyway i don't really know what happened.. it took me a while to get the hang of hitting the crossing restrictions well but i haven't missed one in the last few dozen flights so who knows.. i think maybe i'm just not entirely understanding where the crossing restriction lies, i had found many times in the usa they would tell me to go to 11/12 within 30 miles or less but in reality i had to be down within 15 or less, it seemed like ~40nm from the airport was always the location so i generally just make sure i'm down before then, but maybe that only works at usa airports?cheers,-andy crosby

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you're correct. 40 miles is the magic spot.but if the last checkpoint is more than 5 miles from the airport, then you get the "i need you level in 30 miles or less, descend and maintain 11000" crossing restriction. that is given 70 miles from the airport. so the crossing restriction point, is the same spot from the airportnow if you are slow to respond to that, or maybe you took a 3-pd option from cruise altitude, you're not going to be able to make it.

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hi! thanks for the reply>but if the last checkpoint is more than 5 miles from the>airport, then you get the "i need you level in 30 miles or>less, descend and maintain 11000" crossing restriction. that>is given 70 miles from the airport. so the crossing>restriction point, is the same spot from the airporti'm not 100% sure i get what you're saying here about the difference if the last checkpoint is more than 5 miles away. the alt restrictions is still where my flight path intersects a 40nm radius from the airport right, but they just say a different warning? i usually just make a /40 fix in the fmc (using mainly lds767 or pmdg747) for easy reference on the display and then make an along-track waypoint maybe 5nm before the intersection of the path with that circle, set to the speed and alt restriction. with the exception of the flight i was talking about above, this seems to work pretty well.>now if you are slow to respond to that, or maybe you took a>3-pd option from cruise altitude, you're not going to be able>to make it.yah i got burned by the pd descent enough times that now i just use "des now" when they first tell me to start moving down, which gives me a nice lazy descent until i start moving down the vnav path restrictions and then i end up hitting it pretty smoothly without much trouble. especially if i have winds programmed in and stuff. with pd descents i am generally waay too fast to hit the altitude and speed both if i just start heading down where it thinks TOD should be. what was weird about that particular flight is that usually if i miss the restriction i am only 1-2k above and will get vectored away, then right back when i reach 11k, but this time i was at maybe 11030 and the atc just never really realized i was near 11k and was #### bent on letting me fly away from the airport till who knows when hehe. i think it must have been an altimeter thing but i'm not sure how it could think i was 3k feet too high for a difference of only a few mb of pressure.lately i've found that when everything is setup the lds767 will actually push me down what looks like a perfect path to hit the 40nm/11000 point but sometimes the atc waits a minute too long to clear me below 18k and i end up having to level, then dive and use drag where if they let me go straight down i would hit the along-track waypoint perfectly. as a result if it looks like i'm getting to 18k a little quickly i will start to slow down using mcp speed override and strike a balance there. i think this depends on gross weight i am maybe diving a little fast when heavy, or maybe traffic is causing it to keep me there outside of the optimal dive rate that the fmc wants.(i find sometimes i use lower climb rates to do the same thing, when i hit like 1k below my authorized climb altitude i'll drop to climb2 so i don't have to level out while waiting for clearance. i think sometimes this is just a symptom of how it will take 10-20 seconds for them to talk when in reality it might only take a few seconds to say the same thing in real speech and not having to have the computer parse out each syllable so carefully.)anyway radar contact is awesome one of my favorite mods by far, thanks for the good work :)cheers,-andy crosby

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there is a whole section in the manual about the differences between a regular crossing restriction, and the new one. even an explanation on why one vs. the other.jd

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I use the PMDG 737NGs so the ND and FMC is similar to your models.As you do, I put a 40 nm range ring around the airport fix. I then use the ND descent trend arcs to insure I'll meet the restriction by using MCP V/S. I try to be at altitude five to ten nm early. Sometimes for certain approaches RC may keep you too high because of its averaging MSA methods then order the descent. I also slow the aircraft in advance for preparation of a steep descent as it makes drag devices more effective (if required) and I might ask for a lower altitude before starting a commanded descent if MEAs do not present a problem. I usually have STAR charts for arrival giving MSAs for the approach and they allow me to anticipate the vertical path required. I also use the NOTAMS option enabled so onece approach authorizes it I can start an early descent.If your approach is around difficult terrain obstacles you might find it best to declare an IAP and navigate your own approach following a STAR and published IAP chart (or use your FMC) as with the RC vectoring method it might keep you too high too long. In addition RC's vectoring might take the wrong route assuming a straight in approach where terrain or other rules make this impossible. For example Milan Malpensa (LIMC) has high terrain for a straight in approach in one direction so a procedure turn is required from the terrain safe direction to turn you inbound on final for the assigned runway. In a few cases a visual circle to land is required to accommodate headwind which has determined the landing direction. In these cases RC IAP declared approaches become mandatory navigating them as published. Use your FMC database as a guide and using DEP/ARR enter them into your FMC and close the DISCO. Some freeware and payware FMC databases for your PMDG and LDS are available. FS AI do not do too well with terrain obstacles on difficult approaches and do not perform circle to land and procedure turns to the assigned runway. They are better in FS9 than FS8 but still occasionally travel through terrain in fantasy fashion.If you are traveling outside of FAA areas it is important to know the Transition Altitude to enter in your FMC (in the Boeing FMCs it is to be entered in your descent forecast page). In FAA areas it is always 18,000 feet. I think this was already covered but if RC on climb states your altitude in terms of a flight level (FL160 for example) you set your altimeter to standard pressure 1013 mb or 29.92 in) as soon as you start climbing. If stated in feet leave the altimeter at stated local pressure. Do not use the FS B key as it is hard coded to set the altimeter to standard at 18,000 feet for a transition altitude. In the process of descending if the new altitude is referenced as a flight level leave the altimeter at standard pressure, otherwise set it to the RC announced local pressure. Always use the RC declared local altimeter setting as it can vary along the climb or approach below the TAs. Do not use ATIS announced pressure as at the moment of final it might be different.In the RC options it is set to a 200 foot altitude option tolerance by default. If you wish you can increase this tolerance but then it would not be realistic.

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