That's What an Alternate is For!

Yesterday afternoon. Generally rainy but looking flyable for the weekly commute from Bridgeport to Alexandria.

Everything's goin' good up until about 2330Z. KDCA reports a 1300 foot ceiling and I am cleared for the RNAV (GPS) RWY 6 approach into KVKX. Piece of cake. Enter the approach, fly the course reversal, line up on final and start to descend. 1500 feet at the Final Approach Fix...4 miles from the runway, no joy. Descend to the Minimum Descent Altitude of 680 feet. If I look straight down I see the houses just fine. Looking ahead, I see...nada! It becomes obvious that the ceiling has lowered and this is going to be a missed approach.

I climb away from the airport and report the miss to Potomac Approach. She gives me a climb to 3000, a 180 heading, and a frequency change. The next controller tells me that the bases are reported at DCA at 500 feet. Even the big guys are missing, and it will be at least 40 minutes until they can give me another shot at the approach. "Say intentions."

"Stand by..."

If I go somewhere and hold for 40+ minutes and then spend 20-30 minutes shooting the approach again and I miss again (it will be dark by then and there's no real reason to count on a higher ceiling) then I will have to find somewhere else to go...and by that time I'll have less than two hours of fuel remaining.

I key the mike and ask, "What's the current weather at Manassas?" KHEF is reporting scattered at 1100, overcast 1700,  landing Rwy 34R. I dig out the appoach plates for HEF. There is a very nice RNAV (GPS) RWY 34R with a Minimum Descent Altitude of 620 feet. Sold.

I advise the controller of my intention to go to KHEF and he clears me via radar vectors.

 The approach goes routinely and a half hour later I'm on the ground. At the wrong airport, but on the ground. I rent a car and drive home.

Archival NEXRAD Images

In putting together last night's post describing last Friday evening's flight I wanted to include some images of the weather situation in certain areas at certain times of interest. What I needed was archival images from the NEXRAD weather radar system. Turns out that it's easy to obtain them and I thought others might like to see how.

The whole process starts HERE at the NEXRAD National Mosaic Images site. Click on the "Get/View" menu item to go to the Radar Data Access page.

Click the link to NOAA's Weather and Climate Toolkit, which you will need to download and launch on your computer. It's a Java application and it will check to ensure that you have an adequately recent version of the Java run-time environment available.

Now, back at the Data Access page, click the link for the Nexrad Inventory Search tool. You'll be presented with a map showing the locations of all the NEXRAD sites. Click on the one that interests you. On the next page, select the date of interest (available dates range from about 1992 to "the day before yesterday". It takes about 48 hours for the system to crunch all the data and archive it.) Then in the list box, highlight the product of interest (one of the COMPOSITE REFLECTIVITY images is a good place to start). Then click the "Create Graph" button.

Now you are presented with a graphic that displays the population of available images for the date being examined. Below the graphic you can enter a time range (say, the time of interest plus/minus an hour) and your e-mail address. Then click on the "Order Data" button.

In a few minutes the system will send you an e-mail with a link to a dynamically-generated web page that will list the images available during the time period you've specified. The links will be in a format like this: KLWX_SDUS51_NCRLWX_200905292200. The first part is the station identifier and the last part is the date-time group. Click on the one(s) you want to keep and save them to your local drive.

Now, remember when we downloaded the viewer application a few paragraphs ago? Fire that up. It will present a graphical interface window. Pull down the Data menu and click Load Data. This will bring up a Data Selector dialog. Click the Local tab and browse to the data file you saved a minute ago from the web link in the e-mail.

The app should load the data and, Presto! There's your archival NEXRAD image. You can save it locally as a *.png file and manipulate it with any of the usual graphics software.

A useful tool set.

There Are Two Kinds of Weather...

In aviation, there are two kinds of weather: Bad Weather and No Weather. With a map that looked like this at 7 AM on Friday morning, it was clearly not going to be a "no weather" day in the Northeast:

I filed the usual "preferred route" (preferred by the ATC computer, not by me) from KBDR west to Sparta then south to Solberg, west to East Texas (near Allentown), south to Lancaster, then Baltimore then home. But around 4 or 5 in the afternoon, the radar picture was looking like this:
That top lobe of precipitation (with the nice red and orange markings) had a SIGMET wrapped around it and I was pretty certain I didn't want to go there. So I filed a new flight plan, starting at KBDR then going to Albany, Wilkes Barre, way out west to Selingrove, PA, then back to Lancaster and thereafter as previously planned. The idea was to first get around that northernmost bit of nastiness and then build in a big loop to allow time for the weather in the Baltimore/DC area to clear to the east.

So I got to the airport, pre-flighted N631S, and called for my clearance. I got: Radar vectors to Sparta, V188 to Wilkes-Barre, thereafter cleared as filed. Not what I wanted to hear, as the last radar picture I'd seen (above) made the Sparta, NJ option a bit unpalatable. I decided to accept the clearance and if it started to take me where I didn't want to go I'd say "Unable!" and negotiate a better deal.

But once airborne and headed west, things started looking better. The picture below shows the echoes at 5:30 PM, just a few minutes after I departed KBDR. You can see that there is an attenuated region developing between the areas of stronger echoes, just about where I needed to be going. So far, so good...
By 6 PM, the path between the heavy weather areas was open and comfortable to transit. Clearly, I was going to be able to get behind the northern parts of this frontal activity.
Sure enough, here is a screen shot of the XM weather display on the Garmin GPSmap 396 at 8 minutes before 6 PM. I am right over Danbury (KDXR) and looking down the road toward Sparta (SAX) the coast is clear.
Of course, that left the little problem of getting into the DC area. At 6 PM, when everything was looking good up north, this is what the Sterling, VA NEXRAD facility was painting:
I got to Wilkes-Barre about 6:15 PM and the controller there asked if I wanted to join V93 there and go straight south to Lancaster, omitting the "delaying loop" out to Selingrove to the west. I had been watching the trailing edge of that patch of nastiness down to the south and it seemed like there was a good chance of it clearing out by the time I made it down there around 8 PM. So, I accepted the excellent controller's offer and headed down toward Lancaster. By 7 PM (probably somewhere around Reading, PA) the radar picture down in DC was improving:
And here, below, is the 8 PM situation. All of the really nasty stuff is over to the east, beating up the DelMarVa peninsula and the path from Pennsylvania over Baltimore and into the east side of DC looked very nice:
Here is another screen from the GPSmap 396 at 5 minutes before 8 PM. That's a pretty intense patch at the upper left, but it's a good 50 miles away. I've just cleared BAL and am headed down to OTT (the Nottingham VOR) where I can make a right turn into KVKX. It's nice when a plan comes together.
To wrap up, here is the FlightAware track for the whole 2.9 hour flight:
And in case you're wondering, the flight back up to KBDR this morning was smooth, fast and totally uneventful. Not good blogging material, but a nice way to travel.

Seat Stop Upgrade Courtesy of Cessna

Most folks are aware of a long-standing problem with Cessna singles where the seat track latches occasionally disengage as the airplane rotates for takeoff, causing the pilot to slide somewhere into the vicinity of the back seat. It doesn't take much imagination to understand that this can be a Very Bad Thing.

Cessna has engineered an auxiliary seat stop mechanism to ameliorate this problem, and N631S is in the shop having the solution installed on the pilot's side, with Cessna picking up the bill. (If I wanted the same mod on the co-pilot's side that would be on me.) Here's a photo:

You're looking at the seat upside down on the bench, forward to the top of the picture. A webbed belt on a reel is attached to the main aft cross-piece with a pawl-and-ratchet mechanism visible at the right. The end of the belt has a fitting that will be bolted to the floor of the cabin. The flexible cable gets connected to the bale that operates the original latch mechanism (which remains in place) so that when you lift the bale you release both the main and the auxiliary latches.

It seems to be well engineered and there have been, so far, few reports of difficulties in the field. Looks like a good solution to a real problem.

In Praise of Onboard Weather

Here are a couple of photos from this morning's flight showing the XM Weather display (and specifically the NEXRAD Radar screen) on N631S' Garmin GPSMap 396. The first image shows us over Delaware Bay east of the Smyrna VOR (ENO) near Dover AFB (KDOV) headed toward the LEEAH intersection.

You'll note that the course shown is, for the time being,  nicely free of all those green and yellow precipitation returns.

The next image is a little earlier (note...not yet past ENO) and at a wider scale. I had just accepted a reroute. My clearance would have had me turning left at ENO and going up to Cedar Lake (VCN). The Dover Approach controller said he'd need me to descend from 7,000 feet to 5,000 feet unless I wanted to proceed to LEEAH and thence to Coyle (CYN). A quick glance at the NEXRAD display made this an easy question to answer -- take me to LEEAH! 

The ride was smooth and the precipitation was light as I proceeded through the "alley" where the returns were absent then headed up to the Atlantic City (ACY) area through the region of green (= light) echoes.

Having this kind of information on the airplane provides tremendous confidence and terrific decision support. You know what you are getting into. With the caveat that you must understand NEXRAD's limitations, this is a remarkable enhancement to IFR safety.

About the limitations: At the lower left of each screen image is a data label indicating the age of the information (i.e., Wx -00:06 indicates data six minutes old). In addition, the actual returns might be about five minutes old before the NEXRAD system processes them. So I am looking at precipitation areas that may be, in this case, 11 minutes out-of-date. You must avoid putting yourself into any situation where a rapidly moving cell traps you because you cut in too close to its downcourse side.

This is a strategic tool and a weather avoidance tool -- not a tactical tool or a weather penetration tool. (The latter is the onboard weather radar that the Big Iron carries.) But used for what it is, the NEXRAD/XM Weather/Garmin 396 system is incredibly valuable.

Every Flight is Interesting

Since N631S and I began this routine of a weekly commute, my logbook is mostly "BDR - VKX" followed by "VKX - BDR" and repeat. But while it's repetitive it hasn't been boring. Memorial Day weekend, just past, offers a good case in point.

The flight south on Friday evening was notable for the amount of traffic active in the area of the New York Class B airspace. Just after passing Carmel (CMK) on the way to Sparta (SAX) at 6,000 MSL, I heard from Approach, "Cessna 31 Sierra, traffic...no, actually traffic alert 10 o'clock and a mile northbound at 5,800 type unknown; if you don't have the traffic I suggest an immediate left turn heading 180."

That will get your attention.

I started the left turn first, then looked for the traffic while responding, "31 Sierra is in the turn." Before I'd turned much more than 20 degrees I saw it...a low wing single, perhaps a Bonanza crossing left to right. I suspect the controller took the classic measure of turning me toward where the traffic was so that I'd miss the place where it was going to be. I called traffic in sight, no factor, and got, "Roger, resume course direct Sparta."

About five minutes later the same controller issued this call: "Cessna 31 Sierra, turn left to a 190 heading and climb and maintain 8,000; expedite through 7,000." (If you click on the link above to the FlightAware track, you can see this jog over lower New York.) I hustled on up to 8,000 (to the extent that a normally aspirated 182 will hustle on a warm evening) and shortly after leveling I got a vector back to the northwest, then, "Cessna 31 Sierra, resume direct Sparta, contact Approach on 135.8, thanks for the climb."

Once clear of New York the traffic density lessened and the rest of the flight was comparitively quiet.

On Sunday I finally got to make the trip up to Caldwell (KCDW) and back that I've been trying to fit in for a number of weeks. The trip up was routine except for the last ten miles. Right around Solberg (SBJ) the undercast filled in. KCDW was reporting 6 miles visibility and a 1,000 foot ceiling. The LOC 22 approach was on offer and the nice controller provided vectors to final. We broke out just after the final approach fix and landed. So with what really was less than 0.1 hours in IMC I got to log an approach!

I had filed for the return flight with a proposed departure time of 1430 local but we finished up our business early so I called FSS and moved the proposed time up to 1400. We actually lifted off from KCDW's Runway 22 at 1357 local time and headed west toward Allentown. The NEXRAD display on the Garmin GPSMap 396 showed some storm cells out to the west and north but we turned south toward Lancaster (LRP) and Baltimore (BAL) before they could become a factor. Arriving in the DC area there were lots of showers on radar but we got lucky in that KVKX was the hole in the doughnut. (Look at the FlightAware track linked above and you'll see what I mean.) No drama for the landing.

Today,the first half of the flight from Potomac Field to Bridgeport's Sikorsky Airport was quite entertaining. On takeoff the ceiling was about 800 feet, visibility 2-1/2 miles, with moderate rain. Solid IMC at 7,000 feet until central New Jersey. Then things opened up and the rest of the flight was unremarkable.

So, although I am tracking over the same real estate a lot these days, events and conditions have been quite variable. It makes for good aviation.

The Weekend Commute

Friday's flight down from KBDR to KVKX and this morning's flight back from KVKX to KBDR were uneventful. 2.5 hours down, 2.3 hours back. No significant weather and no squawks. Just the way I like it!

Changes at KBDR

In the early 1970's the city of Bridgeport built a new passenger terminal at Sikorsky Memorial Airport. Over the years carriers like Delta, Continental, USAir, Pilgrim and Air Wisconsin provided scheduled service using Jetstream J-31's, Embraer's, SAAB 340's, BAe 146's and others. Destinations ranged from Groton/New London to Boston, Philadelphia, Baltimore and even Chicago.

For a time in the late 1980's Continental Express flew a useful service to Newark (KEWR) that allowed the business traveler to conveniently access the full panoply of routes and services offered from that hub.

But it didn't last. A number of years ago commercial scheduled air service to and from Bridgeport ended -- forever. The terminal became a place of ghosts and echoes. But change is afoot. Here is a picture of that terminal today:

The (not-really-very) old terminal is being razed to make way for a new executive terminal and hangar complex under the aegis of Volo Aviation. From the linked article:

"The flagship of the Volo chain will be the Bridgeport headquarters FBO at Sikorsky Memorial Airport, where the company is constructing a 125,000-sq-ft facility with 95,000 sq ft of hangar space and two 15,000-sq-ft office buildings. Construction will take place in two phases, starting with one 35,000-sq-ft hangar and one 15,000-sq-ft office/FBO building. Completion of the second phase is expected in the second quarter of 2010."

In an era when small market airports are suffering it's heartening to see positive developments like this being undertaken.

Thoughts on Flight 3407

With the revelations regarding the Colgan Flight 3407 accident that have emerged in the last few days, it appears we are in for a period of extensive and vocal recrimination in press and political fora. Participants will attempt to "spin" the emerging fact-picture to limit their respective liabilities and the usual grandstanders will cry for attention from media and the public.

It is looking ever more likely that Capt. Renslow and First Officer Shaw took actions that caused the airplane stop flying. The pressing question is, "Why?" Why did two experienced professional aviators take actions that were so completely wrong? NTSB appears to be looking at such factors as the quality of their training, fatigue and the exigencies of scheduling, and even whether professional performance can be maintained while surviving on the pitifully small compensation paid to aircrew of low seniority.

I look forward to an assessment of the possible impact on this accident of the well-known and widely viewed NASA Tailplane Stall video. This video and the conclusions of the study for which it was produced have achieved considerable notoriety in the aviation world and, I suspect, especially keen interest from those who drive twin-turboprop transports in wintry weather. The actions of pilots Beck and Renslow in the critical moments -- respectively raising the flaps and pulling the yoke hard enough to override the stick-pusher mechanism -- are exactly the prescribed measures for reacting to a tailplane stall and exactly the wrong measures for reacting to an incipient stall of the main wing. I fear that these pilots were sensitized to the dangers of a tailplane stall without having been formally and rigorously trained in the recognition (including both detection and discrimination) and mitigation of a tailplane stall. If so, it's a tragedy that the dissemination of valid and useful safety information may have been mishandled at the operational level in a way that produced fatal misunderstanding.

As always, we await the final report...

There went the Weekend!

Just a quick recap on the flights down to the DC area back on Friday, and back up to Connecticut this morning.

Although the forecast for KDCA on Friday afternoon suggested that some thundershowers might be in the area, none materialized. There was some convective activity in eastern PA but my route avoided it with no need for deviations. So in the end, the southbound flight proved uneventful.

Looking at the forecasts of last evening for weather and freezing levels in the DC/MD area it would be easy to expect no significant weather for an 0800 local time departure with temperatures above zero degrees C up to 9,000 feet of so. Not the way it turned out.

At departure there was fairly enthusiastic rain, but with good VFR conditions (with the KDCA METAR giving 9SM visibility and 6,500 broken ceiling). So I departed VFR with a turn to the south. Potomac Approach picked me up right away and cleared me up to 7,000 feet (my filed altitude) and turned me to the east.

At about 6,000 feet the rain turned to snow and at 7,000 feet the OAT was 1 degree. Maybe so, but I was picking up rime on the struts, so I asked ATC for 5,000 which they approved quickly.

The interesting weather lasted until Dover, DE and the remainder of the northbound flight was routine.

At KVKX this morning.

This is NX228JK. A North American T-28B Trojan. This is a Big Airplane! 1950's vintage USAF trainer. Some were used in a ground attack role in Southeast Asia.

Here Comes the Weekend!

Planning a 2100Z departure from KBDR this afternoon. From the looks of the KDCA forecast, I suspect I may find some showers to work around as I near home plate.

KDCA 081124Z 0812/0912 23005KT P6SM FEW040 SCT200 

     TEMPO 0812/0813 5SM BR 

     FM081800 21010KT P6SM VCSH BKN045CB 

     FM090000 18007KT P6SM VCSH BKN035CB OVC050 

     FM091000 24008KT 4SM -SHRA BKN020CB OVC030

Most of the TAF's along the expected route are suggesting mid-level CB's, so I may need to request some deviations from ATC around the build-ups.

I have been needing for some weeks to deal with some matters in northern New Jersey and had been hoping to fly up to Caldwell (KCDW) tomorrow morning and return tomorrow afternoon. But the forecast for tomorrow morning looks "iffy".

Monday should be great!

Air Traffic Delays!

I planned an 0900 local time departure from KVKX this morning. N631S and I were at the hold-short line for Runway 6, in the rain, at 0905 and I called for IFR release. Not forthcoming. KDCA is landing south and the final is stretched out 28 miles. Call back in 15 minutes, give us your cell phone number we'll call if we can get you out sooner. Sure. 

So I sat there with the big Continental leaned and idling and called again about 0920. Gee, we had a hole for you but a couple guys went around and the hole went away. We'll call you. I taxied around to the runup pad and shut down.

0930 the phone rings. Potomac Approach has my release. Can I be off in 5 minutes? Sure! After that, the flight was routine. 2.2 hours (of which 0.3 was pre-takeoff) with 1.4 actual instrument time. It ended with the ILS 6 approach at BDR. If you're interested, the FlightAware track is HERE.

Weather!

Yesterday afternoon's flight was entertaining, if a bit long. N631S and I were off of Runway 24 at KBDR at 1717 local time in moderate rain. We went hard IMC at about 1,500 feet and stayed that way for about 1.5 hours. The rain pretty much stopped above 3,000 feet but the clouds were solid until nearing Allentown when it opened up into this:

From there on the flight was in visual conditions. But there were isolated cells of weather to be seen on the Garmin GPS396's XM Weather display. I kept an eye on those with the intention of requesting a course deviation from ATC if needed to avoid the stronger returns -- but in the event, my course never went through any weather during the second half of the trip.

We landed at KVKX at 2000 local time.

Weather...or not?

The forecast for this afternoon at Bridgeport is suggesting gusty moderate winds from the southwest at 2130Z (when I plan to depart) with good visibility in mist and showers. I'm told to expect a 3000 foot broken ceiling, overcast above at 5000 with cumulonimbus clouds. Here's the TAF:

KBDR 011538Z 0116/0212 23010KT 5SM BR OVC006 WS020/24045KT 

     TEMPO 0117/0120 23014G23KT 3SM -RA BR BKN009 OVC020 

     FM012000 24016G22KT 3SM SHRA BR BKN030 OVC050CB 

     FM012300 24012G20KT P6SM SCT030 BKN150 

     FM020100 24009KT 6SM BR SCT012 BKN070 

     FM020400 23008KT 4SM BR BKN012 BKN070 

     FM020900 32006KT 6SM -RA OVC040

The piece of weather that is likely to be over KBDR later is, at this writing, over central Pennsylvania. This is what the State College, PA radar image looks like at 1640Z:

That big yellow blob is headed this way. But there seem to be no lightning strikes associated with it, and the surface conditions are farily mild. As long as it doesn't intensify it will probably be OK to depart once the central part of it has passed...my usual routing will head me to the west over Sparta and out toward Allentown, so I should be going into better conditions.

This all ought to get me into the DC area around 00Z. Here's what the KDCA forecast looks like:

KDCA 011139Z 0112/0212 20012G17KT 6SM BR HZ VCSH OVC013 

     FM011600 21012G17KT 6SM HZ VCSH SCT011 BKN024 OVC035 

     FM011800 21014G23KT 6SM -RA SCT015 BKN040CB 

     FM020000 23008KT 6SM BR FEW020 BKN050 OVC080 

     FM020400 VRB04KT P6SM SCT040 SCT090 

     FM021000 31006KT 5SM -RA BR BKN015 OVC025

OK, that's rain ending about the ETA, going to some mist, few clouds at 2000, good conditions to fly the RNAV 6 approach and may or may not need to circle to land 24.

See you on the other side.