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Saturday, July 30, 2011

100 Minutes

The trip back to the DC area last evening included a very interesting 100 minutes of flying. Just an hour before departure from KBDR, the weather radar showed very little convective activity along my expected route. I launched at 2032Z, as yet unaware that a lot of fast-growing, fast moving convective weather was developing in places that N631S and I intended to be. Managing to stay out of trouble would take all of the resources that I – and a series of great controllers – had available.
As usual, you can click on the images to "big-ify" them.
I had filed for a route across JFK and down over New Jersey, but the ATC computer issued me the "usual route" involving vectors to Sparta, south to Solberg, west to Allentown then south to Lancaster and Baltimore, thence home. This time, I wasn't smart enough to say, "Unable." I knew, however, that it was going to be a long evening when 20 minutes after departure I was still east of KBDR! (This was due to "vectors for sequencing at Sparta," from New York Approach.) I was watching that storm cell approaching Stewart (KSWF) but that one turned out to be the least of my worries.
After another 20 minutes of slow westward progress it was clear that I wouldn't be affected by the cell to the north...but the weather down the route near Solberg (SBJ) was looking like a potential problem. The most pressing matter was to avoid the cell that was then just west of the Broadway (BWZ) VOR. If I got past that point I was confident that a path could be found through the cells then to the south of SBJ.
I asked for an early turn to SBJ, something that's not usually available. This time, the New York Approach controller accommodated me, the first of many times that ATC would help me on this trip. Also, I usually ask for and receive a short cut to LANNA from about 15 miles north of SBJ. This time I didn't request it and wouldn't have taken it if offered as that would have taken N631S and I into some nasty looking weather.
The early turn gave me a little breathing room and the change in course gave a few more knots of ground speed. I started planning to ask the controller for a 270 heading as soon as I was past the threatening cell. Before I could make the request, he said, "Skylane 31 Sierra, let me know when you can accept direct East Texas." I liked that...the course to the East Texas (ETX) VOR would be almost exactly the 270 heading I'd need. Then after 15 to 20 miles of that, I could work out the next bit of strategy with Allentown Approach.
On the way down to SBJ there was some moderate precipitation and occasional light chop for about five minutes, but nothing serious. Just a free airplane wash. That undoubtedly corresponded to penetration of the "yellow" part of the NEXRAD return shown in the screen capture at left.
Very soon after the hand-off to Allentown Approach I asked whether "direct FLOAT" would be a good idea. FLOAT is an intersection near Reading, south of my then current course. The Allentown controller didn't think much of that idea. "This stuff is moving fast," he said, "so by the time you get to FLOAT it'll be there. We need to vector you around it." I was happy to agree. He then added, "31 Sierra, turn left 20 degrees at this time for weather avoidance." The screen capture above left shows the effect of that turn - and yes, I guess the weather was moving fast. I could see his plan...15 to 20 miles on the new heading then a turn to the northwest to exploit the gap between two cells.
At a strategic moment, I suggested that a turn "direct Allentown" looked good to me, and the controller concurred. "Skylane 31 Sierra, turn right direct to the Allentown VOR, that's Foxtrot Juliet Charlie." That course split the cells nicely. On the way through the gap there was only light precipitation and occasional light chop. Nearing FJC, N631S and I broke out into clear air and sunshine. I gave the controller a report of flight conditions between the cells and heard him relay the information to another aircraft that was following along behind me.
I'd reached a point where a turn to the west, along the back side of the cell, would work, so I requested direct ETX and then resume my original clearance. That was approved. For a while I could enjoy the fairly benign conditions rounding the back of that weather...but the fun wasn't over. there was another problem ahead, approaching Lancaster (LRP) from the west. Given how fast that these cells were moving, I was sure that the cell would beat me to LRP and I'd have to work around another one.
Twenty minutes later, the Harrisburg Approach controller had suggested a 250 heading to work around the back of the cell that was raining all over the Lancaster airport. The NEXRAD image at left is 6 minutes old and the weather was already a couple miles east of the position shown, so the flight conditions were pretty mild. 10 more miles, then a turn to about a 210 heading and I'd be out of the woods. A quick look ahead showed no additional weather between me and home.
Just about when I expected it, the Harrisburg controller said, "Skylane 31 Sierra, turn left direct Baltimore, resume own navigation." It had been just about 100 minutes since the weather started to make life interesting. Once again, two important things were reinforced: On some nights, an on-board NEXRAD weather radar display is worth it's weight in gold; and there is no greater asset than to have on your team sharp controllers who have "got the flick."
The rest of the flight was uneventful...which was a good thing. I'd had sufficient fun for one day.

3 comments:

== T.J.== said...

Nicely done! Weather radar is totally worth it's weight in gold!!

Gary said...

Frank,

Great screen shots to document the post. I love having the xm wx on the 496, a big plus in the cockpit.

Frank Van Haste said...

Thanks, T.J., Gary. The XM WX system sets a very high bar for the weather component that is rumored to be part of NextGen (ADS-B in).

Frank