Sunday, September 27, 2009

Warbirds at Cessnock: Albatros, Trojan and Avenger

After shutting down at Cessnock on our $100 wine bottle flight we noticed a nearby hangar with shiny warbirds inside: a T-28 Trojan, a Grumman Avenger, and two L-39 Albatros. All airplanes that rank far higher on the aviation coolness scale than our Piper Archer. But we love the Archer too.

We walked into the hangar and asked for permission to look at the warbirds from up close and snap a few photos. The friendly pilot in a flight suit invited us to join the guided tour, which for $10 each meant we could take as many photos as we wanted, sit in the cockpits and ask all our questions. Bargain.

Let me say it again: we were allowed to sit in the cockpits. In many aviation museums they won't even let you approach the airplanes, probably for good reasons. I've seen a small child hang with both hands from a pitot tube once. But today was different because this was not a museum, this was a hangar full of airworthy aircraft.

This is Ingo on the photo above reluctantly extracting himself from the Czechoslovakia-made jet trainer L-39 Albatros. The Albatros is a very popular aircraft with private owners since it is relatively cheap to maintain and operate as long as you are able to buy it in the first place. The cockpit has a definite military feel to it. The parts that do not have inscriptions in cyrillic characters on them are standard General Aviation avionics, such as the VHF-COM unit, transponder and ELT who are exactly the same models as in our Archer.

Not only are the two Albatros airworthy, they're also available for joyrides. This explains why we were allowed to sit in the cockpits. Just the age-old foot-in-the-door marketing technique: if at first you think $3040 is a ludicrous amount of money for 30 minutes of engine time, after having spent 2 minutes sitting in the cockpit looking at the dials you start thinking of reasons why this may not be so ridiculous after all. This is only 32 times as expensive as hiring a Piper Archer after all. Half an hour in a jet above Cessnock or a cross-country fight from Sydney to Ayers Rock? Entre les deux mon coeur balance.

The other side of the hangar contained a beautiful T-28 Trojan, this time from the other side of the iron curtain. It was used by both the US Air Force and the US Navy as a trainer, and saw some action in Vietnam. As is rather obvious from the photo below, it is a single-engine 9-cylinder radial engine driving a massive tri-blade metal propeller.

Climbing into the cockpit is surprisingly easy thanks to a number of handles and footsteps built into the (lowered) wing flaps. When sitting in the cockpit (did I mention we were allowed to sit in the cockpits?), the controls feel amazingly light, thanks to counterweights. The stick can be moved in all directions with only two fingers. I checked, the control surfaces moved accordingly!

The engine is an air-cooled Wright R-1820-86 Cyclone 9 radial engine, the same as on the B-17 Flying Fortress. A single row of nine cylinders delivers 1425 hp. The dark blue case in-between the cylinders and the propeller is a planetary reduction gear box which allows the propeller to rotate slower than the engine crankshaft. Propellers become less efficient when the linear speed of the blade tips approaches the speed of sound. Linear speed is proportional to the length of the propeller blades, and this is a rather large propeller, which explains why it needs a reduction gearbox while our Archer doesn't.

The last warbird of the lot was a Grumman Avenger. Just like the Corsair, its wings can be folded back for easy storage onboard aircraft carriers where space is at a premium.

Note the old-style attitude indicator with only a white line on a uniformly dark background to signify the horizon. No way to tell if you are up or down if you find yourself in an unusual attitude!

Near the center, right next to the "bomb bay" lever is the "wing folding" lever. It operates the hydraulic system which folds and unfolds the wings automatically, without any external help required. A very very cool training video explains the basics of piloting an F4U Corsair, including spreading the wings. A D-handle in the cockpit is used to lock the wings in place, it may be the same mechanism in the Avenger, I didn't check. The last few seconds of the video show the Corsair taxiing with the wings folded over the top. The Corsair was the fighter aircraft used by Pappy Boyington's squadron in WWII, made famous by the Baa Baa Black Sheep TV series.

I have to admit it is still a bit of a mystery to me how a folding wing can be structurally strong without a main spar going through the wing from the wing box all the way to the wingtip. We are talking about airplanes with no limitations on aerobatics and that can pull out of a dive with a load factor of 7G. All the load seems to be placed on the hinge pins that lock into place when the wing is completely unfolded. But then again, I studied software engineering, not mechanical engineering, so my knowledge is quite modest in that department.

On the photo below, the hydraulics on the right-hand side which control the wing folding mechanism, the ones on the left hand side operate the retractable landing gear, whose leg can be seen at the bottom of the picture.

Here again we have a radial engine, a Wright R-2600-20, but this time it's actually two engines rolled into one: two rows of seven cylinders each acting on the same crankshaft. The two rows are back-to-back, which makes cooling less effective on the back row since it gets less air than the front row.

I found a beautifully nerdy article about how Pratt & Whitney engineers managed to solve the torsional vibration problem caused by having two engines hammer the same crankshaft at a different position. The article relates to a similar engine, the R-2800 Double Wasp. More information that you would ever want to know, but you have to admire the dedication of the engineers who solved such a problem by trial and error, without any computer for simulating vibration modes.

All radial engines leak oil because not all of the bottom cylinders have their valves closed, and oil may also leak from other engine components such as push rods and rocker arms. I suspect the drip tray on the ground comes straight from your regular 4-burner gas barbecue. In the photo above the bomb bay and the cowl flaps are in the open position.

The Albatros flight may be expensive, but in comparison $1500 for 25 minutes in the T-28 sounds almost like a good deal. Too bad my wedding was last month, I would have happily added this item to the wedding registry. Anyway, I'm already very lucky to be able to fly smaller airplanes such as the Archer, so I'll stop here. But a loop, a slow roll or even a take-off in the T-28 must really be something special.

I should never have walked into that hangar. I should never have sat in that cockpit.

Sunday, September 20, 2009

I can't drink I'm flying

This felt so weird and so good at the same time. Sorry, I won't be tasting wine because, you see, I'm the pilot and, well, you know, eight hours from bottle to throttle and all that kind of things. Yes, small airplane, we flew in from Sydney. Beautiful day for flying indeed. My passengers wouldn't mind tasting the Semillon though. And we'll take a couple of bottles back with us, thank you very much. Yes, we walked from the airport. No, walking alongside the highway is not terribly pleasant.

That scene played out at a winery in the Hunter Valley on a beautiful early spring Sunday a couple of weeks ago. Susanne and Ingo had joined me as passengers and plane spotters on a day trip to the wine growing region north of Sydney. And they even brought lunch with them. You may remember Ingo from the $100 burger in Wollongong episode. With his better half around lunch was a lot healthier than the famous Aviator Burger.

We left Bankstown in Piper Archer VH-SFR and proceeded up the GA lane through Sydney's northern suburbs. Approaching Warnervale Ingo spotted a couple of ultralights about to cut across our route, so I made an early right turn to Norah Head lighthouse. We drew a couple of orbits at 1500ft. I could have flown lower orbits at 1000ft or even 500ft but since we didn't have life jackets with us I preferred to stay within safe gliding distance of the mainland.

We then tracked to Swansea, weaving our way around low dark cumulus clouds. Since we were below 3000ft we only had to remain clear of clouds, with no minimum distance from clouds required either vertically or horizontally. So this was all legal. Being legal does not however automatically imply being safe (that'd be too easy), so I kept my eyes out and steered our craft away from the fluffy stuff.

It's in situations like that that I realise how easy it would be to enter clouds inadvertently. I remember sitting at home earlier on reading reports about VFR flights into IMC and thinking "come on, how can you not realise you're about to enter a cloud?" Well, spend only five seconds with your head down in the cockpit looking up a frequency in the ERSA, finding a landmark on the map or twidling the GPS buttons and you've already covered 300m. In the photo above, five seconds would have put me rather close to that big opaque flying collection of water droplets.

Approaching Newcastle we tracked inland and the scenery changed quickly from waves, rocks and beaches to hills, pastures and trees. The skyscape also changed to more friendly-looking fair weather cumulus clouds.

As we were only a couple of miles away from Cessnock aerodrome a Twin Comanche overtook us on our right at the same level The manoeuvre was definitely safe but the pilot lost karma points on this one. A radio call on the CTAF frequency would have been a nice display of airmanship. I followed him to the dead side and we both joined crosswind for a left-hand circuit to runway 17.

We taxied and parked our little Archer III not too far from a hangar full of warbirds available for joyrides, hoping that the Piper would learn a trick or two over lunchtime. We took a very informative tour of the hangar, the best part of course being sitting in the cockpit of an L-39 Albatros, a T-28 Trojan and an Avenger. Photos and details in a future post if I don't forget.

After lunch, which was delicious but way too healthy for an aviation-themed day out, we walked to the Hunter Valley visitor center, very conveniently located a few hundred meters from the aerodrome, and from there to the De Bortoli winery. Not that we had ever heard about it before, but it happened to be within walking distance from the airport. As can be seen in the photo below, patches of wineyards can be found right up to the airport fence, in-between the runway and the highway so to speak.

Wine connoisseurs would certainly tell you that this very unique terroir, right on the extended centerline of runway 35, is responsible for the wine's unique bouquet, a delicate balance of wild strawberries, citrus fruits, fumes of unleaded mogas from the road and unburned avgas sprinkled by 152s doing circuits with the mixture on full rich.

People who already shared a bottle or two with me know that one of my pet peeves is the overly lyrical labels found on the back of rather ordinary wines. I like to think good wine sells itself. And don't get me started on wines bottles featuring a dozen gold medals from obscure competitions held in unknown places.

After replacing burnt aviation fuel in the tanks with bottles of wine in the baggage compartment, we took off again and headed further west up the Hunter Valley. From Cessnock we tracked to the Singleton NDB to make sure we didn't infringe on the Dochra restricted area and then west to Lake Liddell and back the same way.

It's difficult to tell vineyards from other crops from altitude, but there is one thing that cannot be mistaken for anything else in this part of the world: open-sky mines.

We flew back via Cessnock, Warnervale, Calga NDB and Brooklyn Bridge. Good thing I made a number of inbound calls before overflying Cessnock since another aircraft on the frequency was about to drop skydivers over the area. He waited for me to report overhead Cessnock before dropping what pilots affectionately refer to as meat bombs.

The trip back to Bankstown was uneventful, which is good, except for a very, very ordinary landing with some crosswind which saw me float and drift way too far from the centreline.

The great thing with flying with passengers, in addition to making the whole day more enjoyable, eating a healthy lunch and sharing costs, is that they take videos during take-offs and landings. I tried to compress three hours of flying into about 2 minutes of video, result below.

We finished the day at home with a beautiful coq au vin that Nina had prepared while we were away, which of course we washed down with one of the bottles that had survived my landing at Bankstown. Thinking about it, we could call this type of flying trip the $100 wine bottle.

Wednesday, September 2, 2009

Moisture in the air and water in the tanks

The date was sometime in July, and the intended destination was Taree, NSW, with the idea of getting back into cross-country flying. There's only so much pottering around the Sydney basin one can do, as beautiful as it is, and the glimpse of the area I got while competing above Warnervale enticed me to come back.

At first it looked as if I had been very lucky with picking Saturday morning for flying, since this was the only day in the week with no rain and even a bit of sunshine. Even the aviation weather forecast on the day before looked hopeful.

I arrived at the club and checked the weather. The trip to Taree was not going to work. Most of the aerodromes along the way had forecasted or reported conditions with either low clouds, fog, showers of rain or a combination thereof. With full tanks I would be able to fly to Taree and fly back to Bankstown without refueling if I couldn't land. But rain was coming in from the south-west later in the afternoon, reaching Sydney around 4PM which would result in visibility of 4000m, below VFR minimums. I could visualise the holes in the Swiss cheese slowly lining up. A Plan B was needed.

I decided instead to fly an abbreviated version of the planned flight and go to Cessnock via Warnervale and Newcastle. This way I could still fly part of the planned flight, and would be back early enough to avoid the rain. Flight planning took a little while, the flight notification was eventually submitted and I was on my way to preflight the aircraft.

Yes, in the picture above there is actually water at the bottom of the fuel tester. Moisture in the air and cold temperatures overnight result in water condensing inside the half-empty fuel tanks. The phenomenon is more common in low-wing aircraft where the wings are closer to the ground and therefore exposed to lower temperatures at night. This is no big deal at all, just a reminder to always perform a thorough pre-flight. Which I did.

From the ground I could see rather low clouds in the GA lane, but I decided to go anyway since there was enough space between the low clouds to turn back to the airport or go to the training area should the lane northbound be obscured by clouds. Taking off in those conditions pushed me a little bit outside of my comfort zone, but not to the point where I felt unsafe.

I took off on 29R, maintained 1000ft until well outside the control zone and climbed to 2000ft. Contrary to what the area forecast had said, there were still plenty of low clouds still firmly seated in the valleys to the west, over the Berowra area. And it didn't look like they planned on dissipating anytime soon.

After Patonga I adjusted my heading slightly toward Warnervale at 3500ft, with still lots of clouds in the Kariong area. I found Warnervale aerodrome, which is not really a challenge given its prominent location between the Pacific Highway and Tuggerah Lake. One lonely Cessna 152 was doing circuits at Warnervale. I made a call on the CTAF frequency advising everyone I was overflying the aerodrome and kept tracking north.

I flew over Vales Point power station and then over Lake Macquarie. This is Eraring Power Station at the back of the picture above. I was maintaining 3500ft, so you can tell from the photo that there was one point where the weather forecast was spot on: cumulus and stratocumulus clouds with a base of 3000ft.

Swansea was easy to identify thanks to the breakwaters and the bridge. The Aeropelican aerodrome appeared immediately after. How much nicer is it to see it from the bumpy and noisy comfort of a small airplane rather than from the relative comfort of an airliner?

Nobbys Heads was also very easy to find, thanks to the very distinctive shape of the coastline and the lighthouse. If the Williamtown military control zone had been active I would have been in trouble by then, but the ATIS had told me that it was de-active, as is generally the case on week-ends, so all was good.

My aircraft on the day, the Piper Archer VH-SFA, was fitted with a carburettor temperature gauge, so I applied carby heat from time to time to keep the needle away from the yellow zone since there was plenty of moisture in the air. I think I would have done that anyway, but the gauge acted as a useful reminder that high humidity and winter temperatures increase the risk of carburettor icing.

At Nobbys Head I turned left and flew west toward Cessnock. I passed Mount Sugarloaf and its twin masts.

The town in front of me was Kurri Kurri, but where had Cessnock airport gone? Answer: it was hiding under the blankies! The cloud blanket that is. I was at 2500ft by then and the clouds looked much lower than that, so instead of going scud running to find an airport I had never been to before, I decided to head south to Warnervale, which I had planned to overfly anyway on my way back from Cessnock. This way, I would get back onto my planned flight.

I couldn't take a direct heading to Warnervale since this would have taken me over high terrain with little space left between the fluffy stuff in the air and the hard stuff on the ground, so I headed for a gap in the hills.

I flew past the Cooranbong aerodrome, which is no longer used as one can tell from the big white crosses at the threshold of each runway. It's sad because it looks like a very nice airport, with a long sealed runway. Apparently, Avondale College used to run an aviation degree out of here up until 2006.

I overflew Warnervale. The same Cessna with the same pilot was still doing circuits. I tuned the Calga NDB and tried my best to track to the aid. Not a big success, but then again I was keeping my eyes out and not flying on instruments. And I have a proof of that: I could spot Mardi Reservoir, and later Somersby aerodrome.

After Calga I tracked to Brookly Bridge, the entry point for the GA lane southbound. This is the highway bridge right above the cowling in the photo below, not the one more to the east which is only for trains, and also dangerously close to the GA lane northbound.

This was my first time flying the GA lane southbound and everything went absolutely according to plan. I had watched the CASA DVD on flying around Sydney a couple of times the day before, which really helped. I also had the GPS on, just to make double sure I would not infringe on Richmond Military CTR. I even slowed down a little to give me more time for thinking and finding the landmarks.

I found the Berowra strobe exactly where I was expecting it, then identified the power substation, the rifle range to my left and Dural Tanks with the strobe on top. I managed to maintain 2500ft all the way down the lane, with some minor zigzagging around clouds required. The picture above says it all.

I picked up the Bankstown ATIS and started a descent in order to be at 1500ft at Prospect Reservoir. I was about to make my inbound call to Bankstown Tower when a pilot came onto the frequency. One could tell immediately from his voice that he was very distressed. But that's a story I'll tell in the next post. I landed on 29R, taxied back to the club house, shut down, wrote down the numbers and tidied up the airplane.

All in all a nice flight even though it didn't go according to plan, and not even according to the revised plan. This was clearly a case of experience is what you get when you don't get what you want.

I was happy with my decision making throughout the flight though. At every point in the flight I had a Plan B and even a Plan C, so I like to think this was a safe flight. The thorough flight preparation definitely paid off. Flying in marginal weather was a good experience too. Now with the summer ahead of us, I'm looking forward to really making it to Taree sometime soon.