Monday, June 28, 2010

Clearance Roulette (cont'd)

The ATC computer seems to have trouble getting N631S and me a workable clearance for our Monday morning trips from DC to Connecticut. As usual, there's a back-story to the tale.

Early on, I would file something like:
POLLA V312 GOLDA V268 ENO V16 JFK V229 PUGGS at 7,000 feet.

I learned very quickly that I'd be required to descend to 5,000 feet approaching ENO if I wanted that routing. Period. And that was annoying because I'd just used all the AvGas needed to get up to 7,000 where the air was clear and the tailwind stronger.

But a helpful Dover Approach controller told me that if I would accept direct LEEAH V1 JFK etc. I could stay at 7,000. So I started to file for this route:

That's the red line on the graphic above. The V16 route includes the segment shown in green from ENO past VCN and up to CYN.

The route from ENO via LEEAH and V1 works well for me, but the ATC computer seems to have a bit of trouble spitting it out. When I file, and then check the FlightAware.com site to see what routing I should expect, it shows this odd version:

What is the point of inserting ENO into the middle of V268? (ENO is the Smyrna VOR near Dover AFB.) I got a hint this morning when I telephoned Mount Vernon Flight Data to pick up the clearance. The controller said, "Can you hold on for a minute? You have a "pref" route out of my airspace and a "pref" route into New York and I have to get them to mesh." A few minutes later he came back with this:
POLLA V312 GOLDA V268 ENO V16 JFK thence As Filed.

Well, that's not what I want! That's going to make Dover Approach issue me a descent to 5,000. But I accepted the clearance with the intent to try and work something out en route.

As soon as Potomac Approach told me to contact Dover I switched frequencies and said, "Good morning Dover Approach, Skylane 631 Sierra level at 7,000 with a request."

This got me, "Skylane 631 Sierra, Dover Approach. Dover altimeter 29.64, say request."

Me: "Skylane 31 Sierra is cleared after Smyrna, Victor 16 to JFK. Requesting after Smyrna, Victor 268 to LEEAH then Victor 1 to JFK and maintain 7,000."

Dover: "I have your request."

About three minutes later, the Dover Approach controller was back with a routing change. He cleared me present position to ENO, thence V268 LEEAH V1 JFK, rest of route unchanged. Perfect.
But it seems like a lot of effort to do something that ought to be simple.

Well, that's IFR flying in the Northeast.

Since I make these trips every week, I guess some of the controllers are getting used to me. I had the following exchange upon checking in with Atlantic City Approach:

Me: "Good morning, Atlantic City Approach, Skylane 631 Sierra, level, 7,000."

AC Approach: "Skylane 631 Sierra, it must be Monday. Good morning, Atlantic City altimeter 29.62."

Me: "29.62 for 631 Sierra and yes, it is indeed Monday."


Don Brown said...

-- We don't have time to fix things that have been broken for 20 years, Frank. We're busy preparing for NextGen.

BTW, want to bet ERAM gives you the exact same routings??? :)


Frank Van Haste said...

Hi, Don!

I don't doubt that ERAM would do just that. I guess I'm stuck with getting Dover Approach to hack the clearance every week.

I don't mind playing by the rules -- it's just so hard to find out what the rules are!

Thanks for reading...


LarryPetro said...

I've been annoyed by that descent and climb on that route too. Thanks for the tip.

However, the LEEAH diversion is longer. So, I wondered how the time and fuel burn compare for the two different routes. For my Cardinal, I estimate that the straighter/up/down route is 1 minute faster and 0.2 gallons less than the LEEAH dogleg. For ROC/GPH/KTAS for cruise, descent, and climb, I used 0/9/145, 500/7/145, and 400/10/105 respectively. The two routes are close to a wash, to the accuracy of my assumptions.

Frank Van Haste said...

Hi, Larry!

Agreed, the two are probably nominally about a wash, but sometimes the tailwind is better at 7000...and sometimes 7 is on top and 5 is in the schmoo.

Thanks for reading...


LarryPetro said...

Hey, Frank. Our paths haven't crossed at VKX recently. My MO is a Friday flight to Georgetown and a Sunday evening return.

I enjoy your writing.


Frank Van Haste said...


My routine has me departing KBDR Fridays at 1630-1645 local which has me arriving at KVKX around 1845-1900 local, give or take.

I head back to CT each Monday morning, shooting for wheels up by 0745 local.

We'll bump into each other at some point.