Wednesday, March 31, 2010

2010 Annual Inspection (v)

The "Inspection" part of N631S's "Annual Maintenance Availability" is finished. I'm pleased by the small number of issues and discrepancies found after a year when the airplane flew far more than it's been used to in recent years.

The new Lord engine mounts have arrived from Cessna. The photo at left shows the old front right mount as installed. While you can't really see them in the photo, the rubber elements have narrow but fairly deep circumferential cracks.

Mike the IA wants to get the new mounts installed today, and then to get started closing out areas where no further work will be needed. I'm still optimistic that N631S will be ready for return to service by close-of-business tomorrow.

Tuesday, March 30, 2010

2010 Annual Inspection (iv)

We appear to be in the home stretch. I stopped at the airport this morning to drop off the Brackett air filter hardware (it turns out that Three Wing stocks the filter elements) and to check with Mike the IA on the status of the inspection. The only area yet to be looked at is the nose gear.

Mike discovered an area under the rear window that appears to be leaking and so we'll re-seal as needed. There are a few other fairly minor airframe items to attend to, but in total N631S is in fine shape for a mature airplane.

The replacement engine mount assemblies were expected to arrive today. It's looking good for getting everything done by the end of Thursday. That's great, as it will allow me to do a post-maintenance test flight after work on Thursday prior to heading back down to the DC area on Friday afternoon.

Saturday, March 27, 2010

2010 Annual Inspection (iii)

Just before heading for the train station yesterday I got an update from Skip, the Director of Maintenance at Three Wing. He wanted me to know that Mike the IA's effort to pressure lubricate N631S's propeller control cable had been successful, so the cable will not need to be replaced. I figure that to be about $650 worth of good news!

Skip also said that he agreed with Mike's assessment of the forward engine mounts - the old ones have got to go. I anticipated that and told him to order the parts. The parts in question are Lord J-6545-1's and Aircraft Spruce will be happy to sell them to you for $98.50 a pop. Lord Corporation is, of course, the premier name in vibration isolation technology. If you are looking for a little light reading they offer a nice white paper on Aircraft Engine Attachment and Vibration Control

Then he asked, since we were going to install a new air filter, did I want the OEM-style pleated paper filter or the Brackett foam-core filter. And that's an interesting question.

The original filter element included in N631S's design is Cessna part C-294510-0901. The OEM part was manufactured by the Donaldson Company - an old and respected name in air filtration. It's a pleated paper filter that requires replacement every 500 hours. The one that was on N631S's nose had about 420 hours on it but it has clearly deteriorated to the point of dysfunction. Aircraft Spruce offers them for $142.50.

In May of 1992, N631S's original equipment filter was removed and a Brackett Air Filter (Assembly P/N BA 8110) was installed under the authority of an STC. The modification was memorialized on a Form 337. Then at some later unknown time and place the Brackett filter was removed and a Donaldson pleated paper filter was reinstalled. However, the STC that covered the Brackett filter installation was not reversed - so it turns out that I've been flying an airplane for five years that's a teensy bit illegal. We're going to fix that now.

Unlike the pleated-paper filter, the Brackett assembly uses an oiled polyurethane foam core to entrap foreign matter from the induction air stream. The element is replaced annually (or at 200 hours service) and costs about $15.00. As nearly as I can tell either filter type will provide good filtration. If anything, the foam filter may be a bit more effective in dusty environments, but the paper filter may "breathe" a little better. The differences would seem slight and marginal.

The Brackett filter hardware was in the small collection of peripheral stuff that came along with the airplane. So I told Skip we would go with the Brackett filter. All that he should need to do is order a foam element and N631S will once again conform to its paper profile.

Friday, March 26, 2010

2010 Annual Inspection (ii)

There isn't much to report from this morning's visit to N631S's annual-in-progress. The inspection is, I'd estimate, 75% complete with not many squawks uncovered. Mike the IA plans to try addressing the one I knew about, the sticky propeller control cable, later today.

The plan is to "pressure lubricate" the cable by attaching a fitting, pouring lubricant in the end, and then connecting an air hose while working the cable core in and out. If that doesn't produce the desired result then the cable will need to be replaced. Of course, of all of the engine control cables (throttle, prop, mixture) this is the expensive one at about $400 (plus about $200 labor to install a new one).

The forward engine mounts (think "rubber doughnuts") are deteriorated and will have to be replaced. That will involve supporting the front end of the engine with an engine hoist, disassembling the mounting hardware, and replacing the rubber elements. The rubber parts shouldn't be very costly but the labor will run $250 to $350.

Finally, the inlet air filter element has filtered its last, and needs replacing. The rest is "odds and ends", which will certainly add up but are not individually daunting.

I've asked Mike and Skip to call me if they find anything scary as Mike completes the inspection. The target remains to get N631S back and flying next Friday.

Thursday, March 25, 2010

2010 Annual Inspection (i)

The ritual of the Annual Inspection has begun at Three Wing Flying Services. Yesterday I removed all of the "loose items" (like headsets, the Garmin GPSmap 396, publications, tools, etc.) from N631S and Mike the IA started getting into the airplane.

There hasn't been too much progress yet. When Mike checked the compressions there was one weak cylinder. Initially, #2 showed 38 psi (on a day when Continental's service guidance said that 48 psi was the minimum). However, when the prop was pulled through a couple of times and the cylinder rechecked, it came up to 54 psi which is acceptable. The other five cylinders have comfortably high compression levels.

Of course, Mike will inspect all of the cylinders visually with a borescope and we'll hear soon enough if there are any issues.

The spark plugs looked good. There was a fair amount of lead fouling of the lower plugs - not too unusual - but that's why I run fine-wire plugs in the lower positions. They all look like they'll clean up nicely.

There's a bunch more Inspecting happening today, and I shall be visiting N631S again early tomorrow morning for more news. And, of course, AmTrak will have the pleasure of my company this week.

Wednesday, March 24, 2010

Better Late Than Never

N631S finally got to the intended destination last evening - parked in front of Three Wing Flying Services' maintenance hangar - about 36 hours late (due to Monday's diversion as a result of fog).

I got back to KBDL with the rented auto at about 2230Z, pre-flighted in the rain, picked up my clearance and launched a few minutes past 23Z. On departure the METAR at KBDL was:

KBDL 232307Z 32003KT 6SM -RA BR FEW008 OVC017 07/06 A2944 RMK AO2 P0001

In minutes N631S and I were in the clag, not to see anything other than gray in the windscreen until about 3/4 mile final.

In a few minutes more, Bradley Approach abrogated my already brief routing with "Skylane 31 Sierra, cleared direct Bridgeport." Then a short while later, "31 Sierra, contact New York Approach on 124.07." I was ready for that.

Me: "New York Approach, Skylane 631 Sierra, level at 4,000, ATIS Kilo at Bridgeport, requesting the RNAV 29 approach."

Approach: "Skylane 631 Sierra, Bridgeport altimeter 29.46, expect vectors for the RNAV 29 approach."

Me: "New York, 31 Sierra, if you can just clear us to New Haven for that transition we can take the approach from there."

Approach: "31 Sierra, cleared direct New Haven, maintain 4,000."

While it's always been nice to get vectors-to-final for an approach from the controller, I've come to the conclusion that the RNAV approaches, when flown with the aid of a WAAS-enabled GPS like the Garmin GNS-530W, are easier when you get the full procedure as published. The machine just knows what to do.

The METAR at Bridgeport was:

KBDR 232318Z 23005KT 5SM -RA BR SCT008 BKN014 OVC050 07/06 A2946 RMK AO2 P0002

...and a few minutes later when I dropped out of the overcast at about 1,000 feet, there was Runway 29 exactly where it belonged. N631S was shut down and secured by about 2345Z.

Tuesday, March 23, 2010

Diverted by Fog

When I got up yesterday morning and checked the weather for my flight from KVKX up to Connecticut, everything looked good - except for the fact that Bridgeport was reporting dense fog. The METAR at the time was:

KBDR 221052Z 05007KT 1/4SM FG VV001 07/07 A3003 RMK AO2 SLP168 T00720067

But fog usually dissipates. The TAF was predicting better weather from about 15Z onward and nearby Waterbury-Oxford (KOXC) was looking reasonable, so off I went.

The departure from Maryland and the flight up over New Jersey were quick and uneventful. But on arrival in the Bridgeport area, things were not at all improved:

KBDR 221352Z 07007KT 1/4SM FG VV001 08/08 A3004 RMK AO2 SLP173 T00830078

That's a quarter-mile visibility in fog, with a variable ceiling at 100 feet. Well, not likely to land there. I shot the ILS 6 approach for practice and went to the missed approach holding point to wait for a while.

It was nice to watch the WAAS-enabled Garmin GNS-530 driving the autopilot around the holding pattern for multiple laps. While it was so engaged I had a talk with Flight Watch. Bridgeport was fogged in, as were Oxford, Danbury, New Haven and White Plains. The nearest reasonable weather was at Stewart Field (KSWF) in New York and at Bradley International (KBDL) north of Hartford.

After 40 minutes in the hold I asked KBDR tower if they saw any hint of improvement and got a succinct "Negative." So I got back on with Approach and asked for a clearance to KBDL. They obliged with "Cleared present position to Bradley Airport via direct, climb and maintain 4,000 feet." And off I went.

Bradley had their ILS 6 on offer and asked me to keep my speed up (which I did). N631S and I broke out at about 900 feet, landed, and taxied to the TAC-Air FBO to wait some more. But it soon became clear that KBDR was not going to get better for a long time (and, in fact, did not lift to ILS minimums until after midnight). I rented a car and drove to Bridgeport...and tonight or tomorrow night I'll drive back up there to retrieve N631S.

As one of the other diverted pilots at Bradley said to me yesterday, "Well, that's aviation."

Sunday, March 21, 2010

Rainy Days and Mondays

This is probably a good time to look ahead at the conditions forecast for tomorrow morning's flight from KVKX up to Bridgeport. There is weather on the way, in the form (see left) of a fairly large and vigorous low pressure system currently making things wet in Tennessee and Alabama.

Here's the big picture, the forecast of fronts and precipitation for 12Z tomorrow morning from the NWS Hydrometeorological Prediction Center. This is about the time I plan to get off.

It's worth noting that the chart suggests convective activity deep within the precipitation area, but the conditions for the DC area look to be pretty benign.

As always at this time of year, the key question is, "Where's the freezing level?" The map below, from the Aviation Weather Center site, shows the 5C isotherm right over DC at the 800mb pressure level. That corresponds to 6,000 feet MSL. This map suggests that temperatures at 5,000 feet MSL along the route up to KBDR should be comfortably above freezing.

This is important enough to crosscheck with another source. The nice folks at Wunderground have a freezing level chart for 12Z tomorrow (see left) that also gives confidence that icing won't be an issue. For most of the route it looks like the freezing level will be at 8,000 to 9,000 feet MSL.

The Terminal Area Forecasts (TAF's) say that there will be some weather, but nothing too nasty. For departure, I look at both National (KDCA) and Andrews AFB (KADW):

KDCA 211732Z 2118/2218 16009KT P6SM SCT120 BKN250
FM211900 19011G16KT P6SM SCT140 SCT200
FM212300 17007KT P6SM SCT120 BKN150
FM220400 14004KT 6SM BR VCSH FEW015 SCT025 OVC070
FM220700 12004KT 5SM -RA BR SCT008 BKN015 OVC025
FM221100 12008KT 2SM RA BR SCT004 BKN006 OVC009
FM221600 12011G17KT 3SM -RA BR FEW003 BKN008 OVC011

KADW 2118/2217 20012G18KT 9999 SCT100 QNH2995INS
BECMG 2123/2124 17009KT 9999 BKN100 OVC220 QNH2986INS
BECMG 2208/2209 14009KT 6000 -RA SCT010 OVC025 WSCONDS 650905 QNH2975INS
TEMPO 2213/2217 14012G18KT 3200 RA BR OVC009 T25/2120Z T11/2210Z

So for a 12Z departure, National is expecting 2 mile visibility in rain and mist with scattered clouds at 400 feet AGL and a broken ceiling at 600, winds from the southeast at 8 knots. Andrews is looking for a mile in light rain, scattered deck at 1,000 feet, overcast at 2,200 feet and southeasterly winds at 9 knots.

The TAF for Andrews does contain "WSCONDS", meaning "Wind Shear Conditions" - there will be some strong winds aloft. As the map at left from Aviation Weather Center indicates, the cyclonic winds wrapped around the low at about 6,000 feet will be bumping 50 knots over the South Carolina coast, and will be 20 to 25 knots along my route of flight. As a tailwind!

The TAF for Bridgeport (KBDR) looks fine:

KBDR 211925Z 2119/2218 09010KT P6SM FEW150 SCT250
FM212100 13011KT P6SM BKN150
FM220100 10004KT P6SM SCT050 BKN150
FM220900 13004KT 4SM BR BKN025 OVC100
FM221200 11006KT 4SM BR BKN015 OVC025
TEMPO 2212/2216 3SM -RA BKN010

On arrival at about 14Z I should find 4 miles visibility in mist and a broken ceiling at 1,500 feet with wind from the east at just 6 knots. The ILS for runway 6 will probably be on offer.

At this point, FltPlan.com is telling me to anticipate 1 hour + 44 minutes en route. A quick trip!

Friday, March 19, 2010


Tonight's flight from Sikorsky Memorial Airport in Stratford, CT (KBDR) to Potomac Airfield in Friendly, MD (KVKX) can best be described as uneventful. N631S performed perfectly, the weather was benign, and ATC did the usual splendid job.

Here, courtesy of the nice folks at FlightAware.com, is the track of the 2 hour + 18 minute (wheels-up to wheels-down) flight:

And now we get to look ahead to Monday. At present (Friday night) the forecasted conditions for a 12Z departure from KVKX are not bad at all, and the freezing level looks like it will be above 5,000 geet MSL for the route. The only thing that bears watching is a forecast of fog and limited visibility in Connecticut for that time. Right now, I'm expecting to fly.

Thursday, March 18, 2010

Spring is in the Air!

And so am I! After patronizing AmTrak last weekend I've been anxious to get myself and N631S aloft. Last evening after work I met my friend Glen at KBDR and went flying. The mission was to log some approaches under the hood to maintain my IFR currency.

We started out with the ILS 36 at nearby KOXC (Waterbury-Oxford Airport), which was uneventful. I haven't flown an ILS in quite some time so I used this one to exercise the Approach mode on the STEC-50 autopilot. "George" did really well tracking the localizer and I did OK tracking the glideslope. We flew the missed approach and then asked for vectors for the VOR 24 at KBDR.

The only problem with this approach to KBDR was that the very bright setting sun flooded the cabin and made it quite difficult to see the panel through the lower part of the "foggles". But upon reaching the MDA the runway was pretty much where it belonged.

The airport switched to Runway 29, so after we missed again we asked the NY Approach controller to take us around for the RNAV 29 for a full stop. There was a bit of confusion here because the controller thought I asked for the VOR 29 (I dont think I did). But pretty soon his vectors were seeming a little odd and I asked the question and we straightened it out. We completed the RNAV 29 into an even more distracting setting sun. It's a good thing that for most instrument approaches in actual IMC sun glare isn't a problem!

I felt reasonably good about all three approaches. I don't think I'm a menace to navigation.

Southbound Tomorrow

The weather for tomorrow's flight from KBDR down to home plate at Potomac Airfield (KVKX) is looking remarkably good. The TAF's are calling for light variable winds and scattered clouds at 25,000 feet through 00Z. And FlightPlan.com is projecting 2 hours + 15 minutes enroute. It ought to be an excellent flight.

Looking Ahead to Monday

The weekend is forecast to be sparkling up and down the east coast, but clouds should be arriving overnight Sunday into Monday with rain developing early in the day. The key to whether Monday morning will be flyable will of course be the temperatures aloft. And there seems to be cause for some optimism. Below, a graphic of the 850 mb pressure level (about 5,000 feet MSL) chart for 12Z Monday with isotherms:
The colored features show expected precipitation for the preceding six hours. Observe the 0 degree isotherm. It curves to the west of my intended flight track which would be from DC out to Dover AFB then up the New Jersey coast to JFK and thence into KBDR. If something like this forecast happens, I should be good for a damp but safe trip back to Connecticut.

It's That Time Again

Assuming the Monday flight works out, on arrival back at KBDR I will be entrusting N631S to Skip and his colleagues at Three Wing Flying Services for the 2010 Annual Inspection. Much more about that, anon!

Happy Birthday!

Finally, today is N631S's 33rd birthday. It was on 18 March 1977 that this great machine first left the ground and rose into its element from Wichita's Mid-Continent Airport. 3,866 tach hours later it's a healthy airplane, well broken in and with lots of years and hours still to come. I'm honored to be its current custodian.

Friday, March 12, 2010

We're Having a Little Weather

KADW is reporting an overcast at 300 feet in light rain. So, it's an AmTrak evening.

Wednesday, March 10, 2010

Good News, and Bad News

First the good news. I have it on good authority that the doors of N631S's hangar at KVKX are once again functional. Jim, the Wizard of Maintenance applied his Magical Elixir (some type of penetrating lubricant) to the ancient turnbuckles and then carefully persuaded them the turn without buckling, thus restoring the roof beam suspension cables to their desired level of tension. Upon removal of the column jack, the doors slid open and the doors slid shut.

Hurrah for Jim, the Wizard of Maintenance!

And now for the bad news...

It's going to rain, and the forecast for Friday afternoon is not looking any too good. The map shows the mid-Atlantic region enveloped in a complex frontal system and the models agree that the period should feature precipitation, low ceilings and limited visibility. The temperatures aloft are going to be marginal, with the freezing level around 6,000 feet.

I won't be making any decisions for another 24 hours but right now it's looking like AmTrak weather.

Oh, by the way, the flight north on Monday morning was splendid. There was a rather heavy layer of frost on N631S when I arrived at the airport but the rising sun quickly softened it enough to allow its removal and then the flight was 2.2 hours of delightful aviating.

Friday, March 5, 2010

Clear and a Million

The weather did indeed cooperate ...and then some! The time enroute from KBDR to KVKX was 2 hours + 04 minutes runway to runway, with ground speeds mostly in the 145 to 150 knot range. And the weather, for the most part under a broken overcast at or above 10,000 feet, was remarkable. The old phrase, "Clear and a Million" definitely applies.

N631S is parked on an outdoor tie-down due to the problems previously discussed with the hangar doors. I had a look at the concrete cable anchor for the cable-stayed hangar roof and it sure looks to me as if it's been disturbed vertically. The good news is that the roof's been jacked and the doors are closed and secure.

It's promising to be a lovely weekend here in northern Virginia and so far I'm optimistic about the flight north on Monday morning.

Cooperative Weather

The weather seems to be cooperating for a flight from KBDR down to KVKX later today. When I arose this morning we had drizzle and flurries but these soon abated and the sky began to clear. The high pressure ridge running from the Great Lakes to the Gulf is moving slowly but steadily eastward. The map that's forecast for 00Z this evening (above) looks pretty good.

The pertinent TAF's also support an expectation of benign conditions. For the period of interest (roughly 21Z through 00Z) they're calling for nothing more than a scattered layer at about 5000 AGL - which ought to be easily avoided. Here they are:

KBDR 051907Z 0519/0618 35012G18KT P6SM SCT050 BKN120
FM052200 36011KT P6SM SCT050 BKN200
FM060200 36009KT P6SM SCT120 BKN250
FM060600 35007KT P6SM SCT250
FM061300 33010KT P6SM SCT250

KRDG 051724Z 0518/0618 34010G16KT P6SM SCT050 BKN150
FM060000 34010KT P6SM SCT050 SCT120
FM060400 33008KT P6SM SCT120 SCT250
FM061400 32006KT P6SM FEW060

KBWI 051720Z 0518/0624 33010G20KT P6SM BKN070 BKN150
FM052300 34012KT P6SM FEW050 BKN150
FM060500 31007KT P6SM SCT120
FM061400 34010G18KT P6SM FEW250

KDCA 051720Z 0518/0618 34015G23KT P6SM BKN070 OVC250
FM060000 34013KT P6SM FEW050 BKN200
FM060700 32010KT P6SM SCT120
FM061400 33012G20KT P6SM FEW250

Finally, it looks like I can expect an unusual tailwind. FltPlan.com is telling me to plan on a fairly quick 2 hours + 00 minutes enroute.

It's looking like it should be a nice flight.

Thursday, March 4, 2010

Hangar Problems

The maintenance person at KVKX has had a look at N631S's hangar and the news is not so good. In my earlier post on the problems with the hangar doors I pointed out that the structure is about 50 years old, and that it seemed the snow load from our recent storms had deflected the hangar roof causing the sliding doors to hang up on the apron.

The hangar, I'm told, has a cable-stayed roof. Here's a schematic depiction of how such a structure works:

The support cables for the roof span rise from concrete anchors that are buried in the ground, pass over the tops of the upright posts and descend at an angle to their attachment points on the roof beam.

The maintenance person says he believes that due to the snow load (since melted), either (1) the cables have been stretched, or (2) the concrete anchors have lifted from their original locations. In either case the result is a "permanent" deflection of the roof beam from which the doors are suspended.

There are turnbuckles in the cable runs, intended to adjust the tensions and compensate for any elongation of the cables that might occur over time. But after half a century it's likely that the turnbuckles won't be too keen on turning.

The upshot of all this is that the maintenance folk are figuring out how they can fix all this, and tomorrow night when (if weather) N631S and I get back home we'll probably be parking under the stars.

Monday, March 1, 2010

A First Time for Everything

This morning, after a month-long hiatus, N631S and I got to go flying. It felt really good. We were off the ground at 1304Z and headed for Connecticut. The weather in the DC area was clear and pleasant. I'd filed for 5,000 feet based on last evening's TAF's forecasting scattered layers en route at 5,000 to 6,000.

The layer showed up over the Maryland eastern shore with tops at about 5,200. I didn't want to find out for certain weather the clouds had ice in them, but I really didn't want to climb up to 7,000 feet - because Atlantic City Approach always wants me back down to 5,000 feet on V16. The climb wouldn't be worth the fuel burn.

Then, I thought to myself, "Why not?" and pressed the transmit button.

Me: "Potomac Approach, Skylane 631 Sierra, request."
Approach: "31 Sierra, go ahead"
Me: "631 Sierra would like VFR on top at 5,500 to avoid icing in clouds."
Approach: (silence)
Approach: "Would you like to climb to 7,000?"
Me: "Actually, I'd be happier with 5,500 if it works for you."
Approach: (silence)
Approach: "Skylane 631 Sierra, you are cleared VFR on top, maintain 5,500."
Me: "31 Sierra, climb and maintain 5,500 and thanks very much."

In case you're unaware, "VFR-on-top" is a modification to your IFR clearance where you fly in visual conditions above instrument weather, assume responsibility for your own traffic avoidance ("see-and-avoid") and maintain VFR cardinal altitudes. You are still on an IFR clearance. It took the Potomac Approach controller a few seconds to get his head wrapped around the procedure. I guess it's one that he doesn't get to play with every day. Anyway, the layer stayed in place across the DelMarVa peninsula and then went away approaching Delaware Bay. I asked Dover Approach for a return to 5,000 feet and they happily obliged.

I've always wanted to have a good reason to use VFR-on-top and today I got one. There comes a first time for everything, I guess. Now I need a good reason for a Cruise Clearance.

The winds aloft started to get serious over northern New Jersey. Crossing JFK at 137 knots true airspeed, N631S's ground speed was down to 92 knots. We got a little bit back making the turn to the east to head over to KBDR.

When a deep low goes by and the winter winds really howl in from the northwest, KBDR just doesn't have a good runway. Today, Runway 29 was the least of evils. The ATIS was advertising wind from 330 degrees at 22 knots with gusts to 30. That wind 40 degrees off the runway heading will produce (if I recall my trigonometry correctly) a right-to-left crosswind component of about 15 knots, rising to 21 knots in the gusts. Pretty sporty.

I put on my very best crosswind landing hat and got N631S down on the deck with all pieces attached. Yep, it pretty much used up all the rudder. (Getting slowed and stopped was non-trivial. Have to work on that part more.)

All tolled, 2.5 hours (a long one for the north-bound flight) with some interesting notes for the logbook.