Monday, 29 October 2007

DECISIONS,DECISIONS


Cherokee Six 300. Bougainville Island 1965


It was a short twenty minute flight from the small town of Buin at the southern end of the big island of Bougainville in pre-independence Papua New Guinea to Kieta further up the coast.

I was expecting no surprises over this familiar route and with no passengers or cargo the powerful 300 HP Lycoming easily lifted the lightly loaded Cherokee to a safe 3000 feet and I throttled back for the few minutes' level flight remaining before descent into Aropa Airport.

The late-afternoon weather was the usual mixture of scattered showers near the coast and a line of big cu-nims to port where the terrain rose steeply to five thousand feet or more culminating in the seven thousand foot extinct volcano, Mount Taroka with it's crescent shaped hanging lake at the five thousand foot level.

Below, a uniform carpet of thick jungle covered every inch of ground right down to the coast. Typical New Guinea conditions with nowhere to even consider a survivable forced landing. The few sandy beaches were too narrow and short and the only options after an engine failure were to ditch into shallow water near the coast or onto the just-covered barrier reef a few miles out to sea. neither of these was an attractive prospect, but better than flying into the solid jungle below.

The big Lycoming purred contentedly away for a few minutes more and I reached for the throttle to reduce power as the last ridge loomed ahead.

Suddenly, the smooth hum from the engine changed to a shudder which shook the whole aircraft; revs dropped and manifold pressure followed. Full rich mixture had no effect; a quick cycle through left,right and back to both magnetoes changed nothing, neither did switching fuel tanks and bringing the electric fuel pump on line.

First things first. I banked hard right and headed for the coast away from the forbidding terrain below while considering the possibile causes of the rough running. Dropped valve? Tip missing on a propeller blade ? Timing gear slipped? Plug lead fallen off? Ran over a black cat on take-off? "Aviate,navigate,communicate"… The first two disposed of I called Flight Service at Rabaul, far away on the other side of the Solomon Sea and advised them of my situation.
"Are you declaring an emergency?"
" No, but I'm tracking coastal to Aropa for a straight in approach and will call on final"
"Roger"

I was, by then, level at 1500 feet with the steep coastal hills to port and a reassuring light green band of shallow water under the wings.

The vibration got no worse and I made a straight-in approach to Aropa, landed without incident and taxied up to the one and only hangar where engineers, one carrying a CO2 extinguisher at the ready who had heard the whole thing on their hangar radio surrounded the aircraft making throat-cutting gestures which I interpreted as "shut it down NOW."

The reason was soon clear; from both sides of the long engine cowling, a vivid green stain spread fan-like along the fuselage. Avgas. The entire engine compartment was a bomb waiting to explode.

A quick inspection revealed a broken high-pressure injector fuel line which had produced a spray of 100/130 Avgas, filling the cowled engine compartment with an explosive mixture of vaporised fuel and air which neither the hot exhaust manifold nor electrical discharges from the magnetoes and alternator had ignited.

Even now, after a lapse of 30 years I like to think I would have immediately shut the engine down and ditched in the shallows had I known the cause of the rough running, and not continued flying to a safe landing at Aropa.

Thursday, 25 October 2007

Coral Sea Flight


4.30 AM Aropa Airstrip July 1970.The Aztec sits under its reflective silver cover at Aropa airstrip, tail projecting over the edge of the sealed parking area, chocks snug against the wheels..

The darkness is still absolute at this pre-dawn hour and dew beads the upper surface of both wings. It hangs in a stippled opaque curtain on the windscreen and side windows. Mosquitoes whine against my ears in a last try before the dawn banishes them to wherever mosquitoes go in daytime. The heavy flight bag bangs against my leg as I reach the aircraft and start the airman’s traditional walk-around.

Keys out, and unlock the door. Release the seatbelt left looped through the control yoke and pulled tight against wind-induced movement of elevators,ailerons and rudder. Start at the left side. Fuselage looks intact. Left leading edge of the tailplane with its glued-on rubber boot likewise. The elevator moves freely, as does the rudder. Duck under the HF aerial wire running from the right wingtip back to the tail and then forward to a small anchor point just above where I sit in the cockpit. It’s still there….good.

Right flap angled down towards the tarmac and fully extended is intact, and the aileron alongside it moves smoothly up and down when I try it. Wingtip smooth, and undamaged. Front leading edge of the wing also OK. Turn the small catch on the outer fuel tank and remove the inside cap. Stick finger into tank and verify tank full of fuel. Fuel Guages sometimes lie….fingers, never….. Close cap.

Crawl under the wing and remove the small leather cover from the pitot head. Very necessary to prevent wasps and other small insects blocking the tube which feeds the airspeed indicator. Another small hole in the fuselage sends air pressure readings to the altimeter. Check this as well.

The pre-takeoff check continues as I walk around the aircraft. Fuel drained into a bottle and checked for water, or anything else sullying its clear green purity…both propellers free of any nicks or chips… undercarriage looks good, and both tyres are firm under the weight…..We are ready to fly.

Into the aircraft and slide over to the left-hand seat. ( why always the left one?. Orville sat in the middle, but the pilot is now always on this side.) Before me, the panel of instruments and guages stretches across the full width of the cockpit; airspeed Indicator, turn and bank,artificial horizon,rate of climb, altimeter,heading indicator and the rest of the performance instruments right in front of the control yoke. The ADF dial is here with a smaller DME readout alongside it. The VOR dial takes up far too much space and is almost useless anywhere outside a few New Guinea airports The radios are stacked,one above the other in the centre, and engine guages, fuel indicators and some duplicated twins of the ones on my side are all crowded together on the right in front of the missing co-pilot.

Door closed and the handle is held down with an unapproved short length of shock cord. Aztecs have a history of doors springing open in flight. This prevents it.

The right engine starts and the panel come alive. Needles rise from their stops and three small green lights indicate all is well with the undercarriage. The left engine follows, and settles down to a steady rumble. Check the controls by moving the control yoke from stop to stop and fore and aft.
Both trims set to neutral, brakes off, and we roll gently forward towards the runway.

An all powerful, all knowing Department of Civil Aviation, irreverently dubbed ‘The Department of Colossal Aggravation’, has decreed that all aircraft must lodge a flight plan with ATC before leaving on any flight anywhere in New Guinea. Sheer necessity has modified this to allow an aircraft to take off and climb over the airport to enable tenuous high frequency radio signals to reach ATC controllers; they are at Rabaul two hundred miles to the northwest, and on the other side of the mountain range looming above the airstrip which blocks communication from on the ground at this early hour.

A quick call on the short range VHF radio tells other aircraft, if any, that we are moving onto the runway. Light is rapidly replacing the pre-dawn darkness as the aircraft trundles down the long airstrip right to the end, flaps coming up as we roll. The Aztec can, and does, use only a fraction of the length of this one, but why not use all of it if it’s available? The runway behind you,like air in the fuel tanks is high on the list of useless things in an aeroplane.

Stop at the end. Brakes on, and run up both engines to maximum power, cycling the propellors rapidly in and out of their emergency feathered position. A last check for anything on or near the strip which might endanger the takeoff.

Say aloud… ENGINE FAILURE ON TAKE-OFF
60 knots: close both throttles. Land straight ahead.

70 knots: Enough runway left? close both throttles. Land straight ahead.
NOT ENOUGH RUNWAY LEFT ?: Keep straight. Seventy knots. Gear UP. Flaps UP.Power UP. Identify; Dead Foot: Dead Engine. Confirm it with the throttle. Mixture closed. Feather it.
Keep straight. Seventyfive knots. Climb out and go for a safe height.”

A last look around. Open both throttles. Check for maximum RPM both engines.

Brakes off, and I am pushed hard against the back of my seat as the two engines power up. The plane gathers speed down the long runway. Airspeed needle leaves its stop and moves quickly past fifty knots, sixty, seventy……..stick back, and the wheels leave the ground. Maintain seventy five knots and increase the climb. Nothing shows over the long nose except pale blue sky. Wheels up. Start a gentle turn at five hundred feet and start circling to gain altitude for the obligatory call to Rabaul.

Rabaul Bravo Foxtrot Delta
Bravo Foxtrot Delta Rabaul. Goodmorning Go ahead
Rabaul Bravo Foxtrot Delta, goodmorning. Airborne at Kieta. Request weather for Kieta/ Kiriwina.

The weather forecast, when received is identical to yesterday’s and will be same tomorrow. Winds southeasterly up to the ten thousand foot level. Thunderstorms for late afternoon.

Thanks Rabaul. All copied. Ready with details.
Go Ahead.

Flight details sent and acknowledged, we are free to depart. A climbing turn towards the Crown Prince Range which divides Bougainville Island along its entire length brings us over the mountains and we soon reach the green coastal plain on the west coast; beyond it, the Coral Sea. Seven thousand feet seems a good idea today. Just a few fluffy fair-weather cumulus below in an otherwise cloudless blue sky… Aeroplane salesmen’s weather. Woodlark Island is an hour and a half away over the water.

Engage the auto-pilot and let it fly the aeroplane. It does it with less fuss or control movement than any human pilot, including this one. Coffee from the thermos and just sit back and wait for rough running in one of the engines which seems to be part of every long over-water flight.

The sea below is flecked with white horses kicked up by the Southeast Trade Wind. Wind up here is a guess, probably about 25 knots, southeast. No way of telling. There is a radio beacon at Buka, the length of Bougainville away to the north or Kiriwina even further away and ahead.. We just fly what is, hopefully, the right heading and sit and wait.

The ability to identify a dark line on the horizon over a hundred miles away as land and not just cloud only comes with practice and after many mistakes, but today’s sighting is easy. That hard-edged line sloping into the sea under a cap of cumulus cloud where Woodlark Island should be is indeed just that and the tiny Laughlan Islands soon show clearly under the left wing.

Wind the trim wheel forward to start a long descent for the big island, now showing plainly ahead. Turbulence starts to gently shake the aircraft as we leave three thousand feet and gets stronger the lower we descend. No tower or controller to talk to here but Rabaul Radio acknowledges our safe arrival as we enter the circuit for Girua airstrip.

Girua was built by the New Zealanders in the 1940’s for a squadron of Hurricane fighters. Just south of this big island, the Japanese suffered their first major defeat at sea in what was to become known as The Battle of the Coral Sea. The fleet was headed for Australia but a combined force of American and Australian ships intercepted the large Japanese force of aircraft carriers, light cruisers and destroyers and roundly defeated it. Aircraft from American carriers playing a major role in the sea fight which lasted for days before the remains the defeated Japanese fleet fled northwards. New Zealanders in their Hurricanes from Garua airstrip hurried them along.

The reefs around the island still cradle reminders of the battle. Crashed aircraft and other debris can easily seen from low flying aircraft in the shallow water. Teak gratings, portholes and other small pieces of marine debris from sunken warships can still be found in villages.

The airstrip is still in good condition; the original crushed coral retains its hard-surfaced smoothness produced as the scooped up, still-living coral coalesced into a rock-hard concrete runway after salt water was sprayed over the freshly laid surface while heavy rollers trundled back and forth under the tropical sun. The only aircraft using it now are a fortnightly Britten-Norman Islander and me. I come here every six weeks for a load of the beautiful wavy-patterned striped ebony carvings which are almost unique to Woodlark.

The light skinned inhabitants call the island Murua. It is part of the age-old trading and cultural exchange route, The Kula Ring, which still moves in a huge circle around the Louisiade Archipelago. Highly polished jade axe heads originate from this island and are used as ceremonial exchange items, as part of the ring. They come from Suloga on the island’s south coast where a quarry has provided the inhabitants with dark green jadeite stone for centuries. There is also gold in the hills here, and Australian miners risked fever and the clubs and axes of the warlike Muruans early in the 18th century in search of it. Many succumbed to one or both and mining ceased shortly after World War 1.

Nothing remains of those early enterprises. A single white family maintains a small plantation at Kulumadau. The planter augments his income by trading with the Muruans for finely worked wooden bowls carved from the island’s striped ebony logs.

We roll to a stop alongside the solitary windsock and the engines are shut down. A small grass hut holds a collection of cartons and loosely stacked striped ebony carvings left by the planter for collection.
The quality is uniformly excellent with all items showing the finely finished incised patterns which enhance these polished bowls and carvings, all are finished with a wetted cloth impregnated with talc-fine sand from the beach alongside the airstrip. No checking for faults is necessary and a cheque is left in the hut. This is New Guinea, where business is done with a handshake or a brief radio conversation and honest dealing is taken for granted by people who rarely meet face to face.

The Aztec is filled with its load of carvings. Fuel from a drum left for us in the long grass is pumped into the tanks, and I taxi down to the end of Girua strip and take off to the east.

With a full load, the climb to cruising level is slow, but we level out at six thousand feet and head for home. A layer of cumulus below now gives only an occasional glimpse of the sea where white-caps still show the direction of the southeast surface wind. Whatever the windspeed up here is, it is now against us and the return flight will be slower.

The NDB radio beacon at Kieta is not to be relied on at any great distance due to the deflection of the radio signal by the mountains of Bougainville, but the peaks of the Crown Prince Range show clearly over 50 miles out. The weather is still good out here and both engines have settled down to a contented synchronised rumble. As we approach the west coast, build-ups of towering cumulus cloud appear behind the range heralding bad weather on the east coast where Aropa airstrip awaits us. Turbulence disturbs steady flight, causing slight continuous shaking the closer we get to the coast. Height must be maintained until we are clear of the high central range where cloud now sits in a grey blanket with only the highest peaks of the mountains showing above it.

Over the range and it’s time to descend. The signal from the Kieta beacon is now loud and clear. Just as well, as it will almost certainly be unofficial instrument let-down today. I am instrument rated, but the aeroplane is not, due to the cost of keeping it maintained and equiped for legal instrument flight and the distance from a suitably equiped facility to carry out the regular inspections. We have a panel loaded with navigation aids including marker beacon, Distance Measuring Equipment and VOR, all good to have but Kieta has none of these, just the solitary NDB now beeping its identifying signal loudly in my earphones.
The needle is rock steady, pointing directly at the antenna behind Aropa airstrip. The needle wavers, hesitates, then suddenly reverses to point directly behind us. We are over the unseen sea below and clear of the mountains.

Power off, and we descend in cloud towards a turning point over the unseen Zeune Islands, eleven miles offshore where a 180 degree turn puts us on a return course for the northern end of Aropa Airstrip. No point in looking for it yet. We are in solid cloud. Fly the panel and watch the rapidly unwinding altimeter. Light rain spreads a gauze film over the perspex windscreen with a minute left to go and no sign of a break.

If this was a commercial operation with paying passengers to consider, as well as Big Brother DCA, the approach would have to be abandoned. A turn away from the unseen land ahead and a retreat to a different airstrip would be mandatory, but as with many things aeronautical in New Guinea, expedience, experience and familiarity with the idiosyncracies of local weather allow me to press on.
1500 feet and still no break in the cloud. 1000 feet is my personal minimum here and this is rapidly approaching when we emerge from the cloud, and the airstrip appears ahead with a heavy shower approaching from the hills.

No time for a full circuit. A quick radio call to alert anyone else in the air around Aropa gets no response.
Wheels down. Landing checklist methodically ticked off and we straighten up for a final slide down the last few hundred feet until the first cone markers at the end of the runway pass beneath us. Power off……stick back……back… back… ri-i-ight back and the wheels touch the runway with a satisfying squeak.

Rabaul Bravo Foxtrot Delta—landed Kieta at time three zero. Cancel Sarwatch.
Bravo Foxtrot Delta…. Kieta…. Sarwatch terminated Rabaul. Good afternoon.
Bravo Foxtrot Delta . Apinun.