flyinhawaiian Posted May 11, 2011 Report Posted May 11, 2011 This is happened to me twice, and I'm wondering how the FMS is designed to handle STARs. Yesterday, I was flying from KTPA to KRDU and had everything loaded in correctly, including my arrival into KRDU, BUZZY6 arrival > ILS 05L. So I'm flying along, and hitting my descent points when I noticed my proposed destination is about twice as far away as I was supposed to be. All the waypoints for the approach were loaded in, but what I'm noticing is that it takes you over the airport,performs a missed approach, hold, then the actual approach. I think its great that the missed approach is loaded into the FMS, but it should be AFTER the arrival point.So in this case, it went: BUZZY > RDU (last point on the arrival procedure) > RWY05L > DUHAM > (HOLD) > SCHOO > WEPAS > KRDUwhereas it should have been: BUZZY (actual last point on the arrival procedure) > SCHOO > WEPAS > RWY05L > DUHAM > HOLD > KRDUI hope this makes sense, but essentially what I am saying is the FMS seems to want to take you over the airport, then hold, then the approach, rather than go into the approach straight from the arrival procedure. Not sure if this is by design, but it makes flying accurate sorties tricky, at the end...
philipp Posted May 11, 2011 Report Posted May 11, 2011 As I don't know the procedures of KRDU, I can only speculate:There are a lot of STARs out there that are not to be combined with an approach transition. Like, there is a STAR for the non-RNAV equipped aircraft (that ends at the IAF), while the RNAV-equipped aircraft usually fly an RNAV approach transition (or, as most common in the U.S, are vectored in) that starts at some intersection and not at the IAF.Selecting a STAR and an RNAV approach transition where the STAR is not related to the transition will confuse the FMS.So either you are selecting an inappropriate transition or there is something wrong with the procedure data at KRDU.An error in the FMS is unlikely, since the very same algorithm is used in vasFMC for like 5 years now, and if it was wrong, someone would have noticed before.Philipp
flyinhawaiian Posted May 11, 2011 Author Report Posted May 11, 2011 Well I tried to do the same thing into JFK, which has probably been flown a few times before . Again, at the end of the arrival procedure (CAMRN4) it took me to the hold of my selected RNAV approach (RNAV (GPS) RWY 22R) then to the IAF, rather than taking me to the IAF and each subsequent point after that, THEN the hold. I'm burning a DVD right now, or else I'd jump into the sim and get some screen shots, but I'll do some more testing and see what I find...
mutestyles Posted May 11, 2011 Report Posted May 11, 2011 lol its prolly our inexperience with an FMS functioning how it should be lol
YYZatcboy Posted May 11, 2011 Report Posted May 11, 2011 That's why you are supposed to review the waypoints beforehand. Just delete any that you don't want to fly.
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