I’d like to build up my knowledge in how to fly IFR approaches correctly, so any expert, real world pilot, or flight instructor is very welcome to chime in. Today I flew the following VOR DME arc approach (KLMT Rwy 14):
are you even allowed to fly the DME arc like this (coming in from ‘outside’ inbound on radial 265), or do you have to first fly to the VOR (LMT) and then begin the procedure with the outbound radial 265?
the altitude noted on the arc segments on the approach plate, is this a mandatory (‘at’) altitude, or just a minimum altitude (‘at or above’)?
if it is a mandatory altitude then it also means I have to already be at and enter the arc at LEIFF at 11300 ft, correct?
the above has two arc segments, where the altitude restriction changes at NECIE. When would you start the descent to 9500 ft - after you cross NECIE, or before that (so that you are at 9500 when you cross it) ?
are the entry / exit fixes on the arc (LEIFF and MUPEE) fly-over or fly-by waypoints?
Yes, what you did there is allowed, you would not fly all they way into the VOR first. The approach is not applicable if you came in from 314 up to and including 351 radial as stated.
This is the minimum altitude for that arc segment.
No, you can be higher but ATC would likely have given you direction to descend and maintain that altitude.
Yes, after you cross NECIE, not before.
LEIFF is a fly-over and MUPEE is a fly-by waypoint as indicated by the arrows.
WOW ! great topic.
Honestly I don’t remember when last time I flew an ILS Arc, probably when I was instructing 4 years ago.
Since there is 2 tricks to fly the arc I wonder what was your way ? Did you use the CDI or RMI ?
Just curious.
In these days of Radar equipped airspace and NexGen, you will be Radar vectored 99% of the time, unless you you lost Radios or Radar is done.
I looked at a few “how-to’s” for flying DME arcs, and picked up the ‘twist-and-turn’ method using the CDI - intercept the arc on the initial radial with a 90 degree turn, advance the CDI to the next 10 degree radial, fly until needle is centered, turn 10 degrees and advance CDI by 10, rinse and repeat. I’m flying all this with AP / heading mode (don’t know if this is usually flown by hand in RW), I found that I can easily stay within ± 0.5 to 1 mile within the arc. It’s a lot of fun, especially when utilizing the Logitech multi panel and a separate CDI FIP, so I often pick these kind of approaches when they are available, instead of a boring straight-in
Just curious, how do you fly an arc using the RMI? Is it as easy as with the CDI?
Yeah I bet (unfortunately I don’t see this happening any time soon with the simplistic MSFS ATC…)
So the RMI Idea is the same that with the CDI needle except you keep your RMI VOR needle 90 degrees perpendicular to your heading while keeping and eye on the DME. In theory without wind you will perform almost perfect circle however if you need that wind direction you just increase or reduce your angular difference into or away from the VOR. While keeping your RMI VOR needle at the 90 degrees mark you put the actual ILS final approach course to 134 (in your case) so you don’t forget and overshoot the radial.
Most Of my students actually found this method easier since the reference of both needles will give them good visual indication of how far they are from the final approach course.
Try it and see for yourself
Remember to tune NAV 1 for the ILS and set the course while tuning NAV 2 for the VOR so you can read redials in and out using the tail and head of the needle.
Also forgot to add… Using this method you don’t turn every 10 degrees but doing a nice continuous turn with keeping the needle precisely at your 90 degrees with small correction for error.
Awesome, thank you for the explanation! Since I mainly fly the TBM, would I be able to do this with its HSI too (it has two bearing pointers that can be set to VOR1 or VOR2)? I’ll also check fipgauges.com if there is an RMI gauge available for the Logitech FIP…
This is why glass cockpit + GNSS + AP = profit. The technology is there at the push of a single button. Nowadays whenever I see steam gauges and needles and whatnot, I just think I’d rather go on foot.
They make life easier in certain ways, I flew a DA42 in summer and it was really nice to have everything you need in front of you, no brain calc etc. But if you’re not IFR certified and fly purely for fun in charlie conditions it’s money you can better spend in flight hours. Many flight hours.
I did today, and it was great! I dialed the VOR frequency into VOR2 of the TBM’s HSI, and the ILS localizer into VOR1 with course set to the lead radial. Kept the VOR2 bearing needle horizontal throughout the arc and was able to stay within 0.2 miles DME distance, nice round circle. And when the VOR1 needle centered I started to make the turn to final and switched to the localizer frequency. All in all I found it indeed much easier than the twist and turn, so thanks for the tip!
And yes, of course one can just push a button with today’s GPS tech, but where’s the fun in that…
Fly-over fixes will have a circle around them, all the fixes on this chart are Fly-by. On a Jeppesen approach chart all altitudes are minimum altitudes otherwise they will be labeled as “MANDATORY”, “RECOMENDED”, or “MAXIMUM”. Here is a great great reference for Jepps charts: http://www.silviopini.ch/upload/download/glossary_legends.pdf
SEE?! This is why it was a great idea to start a topic like this. There are knowledge people who love to comment on stuff like this, and there are those who want to try out what they’ve learned and ask more questions or provide good feedback.
Brewer’s link to the Jeppesen glossary / legend is good stuff:
