Monday, February 25, 2008

Nav1 and plenty of venturis at Wondai

Last Sunday I went out on a navigation exercise with Lee to Wondai (YWND) via Kumbia and came back to Redcliffe via Kilcoy. Redcliffe Aero Club members will recognize Nav1 of the PPL training.

All the navigation was done by dead reckoning. We left Redcliffe at about 11AM and tracked to the north-west, passing the townships of Hazeldean on Lake Somerset, Blackbutt, the Tarong power station and Kumbia. The flight was very enjoyable, with scattered clouds at about 4000 feet, a headwind between 10 and 15 knots and hazy conditions. We did a few corrections for drift using the 1-in-60 method as well as a ground speed check which gave us a figure of 100 knots.

At Kumbia we turned to the north-east and soon had Kingaroy under our right wing. We made a call on the Kingaroy CTAF frequency to let everyone know we were in the area. The Gordonbrook reservoir appeared under our left wing, then the township of Tingoora. Just a few minutes later it was time to start our descent to Wondai and think about how to join the circuit.

There was only one other aircraft in the CTAF, a Texan. I joined crosswind for runway 18 and performed my first landing on a grass strip. The grass was about a foot high, which definitely qualifies for "long grass" on the performance charts! The surface of the strip was uneven, and I had to keep the control column pulled all the way back to prevent damage to the nose wheel and propeller. We shut down, ate our packed lunch in front of the terminal building of this peaceful little airfield and enjoyed the serenity.

I took a few minutes to walk around camera in hand. Wondai is home to the Barambah District Aero Club, which was officially opened by none else than infamous former Queensland Premier Joh Bjelke-Petersen.

Around the corner from the clubhouse, I noticed two airplanes in open hangars.

The first one is a small taildragger with rego VH-MSP. The VH Register tells us that it is an Auster J5, first imported into Australia in 1951. Searching the Web, I discovered the work of Ed Coates, who has been collecting pictures of aircrafts for the last sixty years. His amazing Web site has two older pictures of VH-MSP taken in 1964 and 1990. It further identified the type as an Auster J5 Adventurer.

The type was first manufactured in England in 1947 by Auster Aircraft, a British light aircraft manufacturer which ceased production in 1968. Quite a few of these planes made their way to Australia. There are some beautiful pictures taken at the Auster Rally 2007 in Wentworth in south-western New South Wales. The next edition will take place later this year at Goolwa in South Australia.

The aircraft has a surprisingly narrow engine compartment, about twice as tall as wide, with 4 prominent exhaust pipes on the underside. This looks a lot better than the ugly exhaust manifold that can be seen on these pictures of another Auster J5.

The vacuum system is driven by two venturis, one on each side. The venturi on the port side is rather small and looks similar to the venturis found on Tiger Moths, or at least is similar to the picture of a venturi used on a Tiger Moth and featured in Bob Tait's CPL Aerodynamics. the venturi on the other side is similar in size and shape to the venturis of older Cessna 172s, such as VH-DCO stationed at Redcliffe.

I could only open the door a crack to take the picture below. I would not have wanted to enter the cockpit further anyway because of the scary flying insects inside, some of them about two inches long. According to the placard on the instrument panel, the plane was (or still is?) used for glider towing. Wondai is a pretty popular place for gliders and has a winch launch system.

The J5 type was originally designed as a 4-seater, however the placard clearly says “No Passengers” and “Pilot Max Weight 100kg”. Although the aircraft is fitted with dual controls, these were probably only used for training with no glider in tow. Pilots are rarely the jockey type, and the likelihood of finding an instructor and a student with a combined weight under 100kg can be safely considered as statistically insignificant.

The instrument panel is rather antiquated. It has rocker switches for the two magnetos instead of the rotary switch found on modern aircrafts. The Airspeed Indicator shows a stall speed of about 56 knots clean and 30 knots with flaps down. In addition to the altimeter and magnetic compass, one can find oil temperature and pressure gauges, as well as a massive turn coordinator in the middle and a tachometer on the side. A Vertical Speed Indicator (VSI) was added later and sits on top of the dashboard. Only the left stick has a Push-To-Talk button. I couldn’t see any radio inside though.

In the next hangar I found VH-DID, a 1963 Cessna 172D, with two identical venturis, one on each side. The D model was the first one to feature the so-called Omni-Vision rear window which improved visibility but also increased drag.

There was virtually no wind when we started up again, so we decided to take-off on runway 36, which saved us having to taxi all the way back to the threshold of runway 18 over bumps, holes and grass. We took off, kept climbing on downwind and left the circuit overhead to the south-east in the direction of Kilcoy. The tip of Lake Barambah was about the only good navigation fix on that leg. Lee recognized Mt Monsildale, but I wouldn't have found it on my own. We found Kilcoy where we expected it, at the top end of Lake Somerset, then crossed the ranges and started our descent towards Redcliffe, leaving plenty of space between ourselves and the overlying Class C airspace.

Approaching Caboolture I made a radio call to say that we were 10 miles west and tracking for Redcliffe, only to realise that I had made the call on Brisbane Radar frequency... Oops. The call was promptly re-issued, this time on the correct frequency. We made our inbound call for Redcliffe just as we crossed the power lines west of the Bruce Highway. Lee asked if I was really sure I was 10 miles inbound. I said yes, then he pointed at the GPS that he had configured to display the distance to YRED. It showed 9.7 miles, not too bad :-)

As I was at 1500 feet overflying the live side of the circuit at Redcliffe I could see VH-MSJ right below me turning base for 07 at 1000ft. We continued to the dead side, descended to circuit height and joined crosswind for 07. The wind was straight down the runway, a very unusual occurence at Redcliffe. I landed on 07, parked between then hangars and shut down. Lee went back in and I took a few minutes to clean up the plane, write down the figures and repack my stuff.

Before leaving in the morning I had followed Lee's advice to put the flight notification acknowledgment printout at the front of the airplane folder, with a big SARTIME written across it. This was a smart move since otherwise I would have forgotten to cancel SARTIME. I called CENSAR over the phone, gave our callsign VH-RAQ, place of arrival and nominated SARTIME, and the person at the other end of the ligne confirmed the cancellation.

In the short debrief Lee explained to me how to use the DG to establish the airplane on track when leaving an airfield without overflying. He remarked on a few other things, such as the fact that I had started my fuel log using departure time and not the time of engine start-up, and that I did not properly monitor oil pressure on start-up. Appart from that he was happy with mu flying, and nav1 was therefore called a success.

Next step is my GFPT test next Friday. Back to the 152, I'd better make sure I go over the aircraft speeds and procedures again. The forecasted weather is showers of rain with lots of clouds and a near-direct crosswind of about 20 knots... Let's see if the test happens. I really hope it will, otherwise I will have to postpone it for at least several weeks, which would prevent me from going solo on navigation exercises, which would seriously delay the advancement of my PPL training. But I guess I shouldn't complain about the rain.


Kelly said...

Good reading, thanks! I'm doing my nav 1 to Wondai a couple of weeks from now so some useful things picked up from this.

Julien said...

Thanks Kelly! Good luck with Nav1, you'll see, it feel so good to leave the training area and cross the ranges!