Interesting Approach

[Carl S]

My instructor and I had planned some IPC work this weekend and decided to meet up at KAFW Friday morning. Due to the clag (and probable ice) it just wasn't going to happen. Instead I gave Bill down at "MotionAir" a call to see if he had some open time. He did, so I jumped in the car and headed down to Midway (KJWY).

After a gournd brief on the training device (sim) we started off with an easy LNAV to RWY 36, nice way to get in some local practice without picking up white stuff. Bill set up local conditions so we broke out about 1200-1300 and I could just see the PAPI ahead so we continued to landing. Well, I did pretty good and was not as rusty as I thought.

THen I learned that Bill can have a bit of a mean streak as he set me up with this thing at Martin State (KMTN): VOR/DME OR TACAN Z RWY 15. Wow! This thing had me really working it. It is a DME arc with stepdowns all the way to MDA. As I got close to R-060 I noticed was off on the arc a bit and told Bill that I'd be looking for the runway environment out the right side of the windshield. He said I might try the passenger window, as he just saw the lights go under the wing. Doh! I guess I was a bit off on the radial also. Missed approach is a climbing right turn into another DME arc! That one worked better for me and after a circut in the hold we finished up with a debrief.

All in all a nice way to get some practice on a day that I'd otherwise be grounded.

< edit> btw - I use the term "mean streak" with high regard. Just thought I'd throw that in since voice inflection can't really inferred.

[Jerry 5TJ]

I learned to fly at KMTN and got my instrument rating there.   As a new aviator I naively assumed curving "DME arc to final" approaches were common but in the decades since I've never seen another one elsewhere.

 

As I recall we flew it by turning the OBS to center the needle to show the desired heading to fly - desired heading is read from the 90 degree mark.  One eye on the DME to keep it near 14.7 miles while you twist the knob and maintain normal scan.  At CUMBE on the 021 radial the OBS mark at 90 right is 111 and that's what you fly +/- wind:  In those pre-LORAN days you had to add a guesstimate of the wind as well to get ground track correction.  Of course the wind correction changes continuously as you fly the arc....

KMTN_DME_ARC_Approach_15.pdf

[Carl S]

This is the only DME arc to final I have ever seen also Jerry. We have a couple of DME arcs down at Waco (http://www.airnav.com/airport/KACT) that I have practiced, but no extra workload with step downs. I am looking forward to trying KMTN again sometime.

[RJBrown]

 Only DME arc approach I ever flew for real was into Quincy Il (KUIN) on my first flight in N231NH after it was converted to a Rocket. Long story but I had picked it up in Lancaster PA and needed a fuel stop en route to Denver. Seemed like it took forever to complete the approach. All the while I was circling around a commuter on the ground was waiting impatiently for me to clear so he could leave. Nowadays they have an ILS and 6 GPS approaches. 18 years ago all there was was just an NDB and a VOR/DME. Sidney NE (KSNY) still has DME arc approaches. Those I have only flown under the hood. Good thing I had the practice otherwise I would have had a bit of trouble when that one confronted me in Illinois.

[smccray]

That looks like a challenging approach!

 

There's a DME arc at Longview (GGG) as well if you're looking for arcs for practice.  If my memory is correct it's on the ILS 13 approach.

[wishboneash]

That looks like a challenging approach!

 

There's a DME arc at Longview (GGG) as well if you're looking for arcs for practice.  If my memory is correct it's on the ILS 13 approach.

 

There is a long straight in segment unlike continuous DME arcs to the threshold at KMTN. A tricky approach is the VOR 19R approach into Concord, CA. There is a 20deg course change after crossing the VOR within 2 miles of the runway. You miss that turn and you do a missed approach!

 

http://155.178.201.160/d-tpp/1312/05320V19R.PDF

[John Pleisse]

In and around the Potomac Tracon, many use Martin State. It's pretty busy there, too. Turn 10 twist 10, baby!!

[M016576]

DME arcing is 100 times easier with a RMI versus an OBS or HSI.

[mike_elliott]

There is an interesting one at KHUF, BC DME 23. FAF is identified by an offset VOR. Makes for fun checkride practice! I miss giving this one to students now that Im in Florida

[John Pleisse]

LDA into Roanoke, Virginia is a good one.