So there I was, sandwiched on a Greyhound to Port Elizabeth, uncomfortably mashed in the non-flying bus, a dream come true, I was on my way to light my first turbine, my first PT-6. More specifically a PT6A-114A, producing 675shp. Any guess's what that may be? Oh yes.... Caravan.... Cessna's Swiss Army Knife with wing's, and man oh man, was I excited!!!
I don't know why, but I always had an infatuation with turbine's from day one. I couldn't explain it, every time a Pilatus PC-12 started up or spooled down on the apron, where I learned to fly, I would stand there and drool offensively onto the tarmac. I loved the wine and seemingly endless acceleration they had on takeoff, so much more refined and smooth then their piston cousin's. It's funny, a lot of the time when you fly an airplane that you have dreamt of for a while, it let's you down. It's not as cool as you expected it to be, but this time it exceeded my expectations. What a plane!
After the passengers are loaded for the heavy load section of the conversion, a mixture of instructors and student's captured among Port Elizabeth's apron. Rear door closed and latched and load bar removed from under the tail, a final walk around checking hatches and doors closed and prop area clear. A climb up the mini air-stair into the cockpit find's me in a hugely spacious cockpit. Comfy seats and 5 point harness', controls and instruments where they should be.
Familiar and well positioned, fuel tank selectors both to ON, bleed air switch off, beacon light to position ON, fuel and firewall emergency in the normal position, trim neutral position and elevator trim for takeoff. Control lock's removed, fuel condition lever in idle cutoff position, propeller pitch lever fully fine, power lever idle position, inertial bypass separator normal position. Call for start-up, cleared for start-up from ground control, gauge and instrument check as well as ensuring beacon light is on. All engine control switches in the correct position for a battery start, ensuring ignition switch in the normal position, electronic master switch goes on, electronic gyro's start to spin and a quick check on the voltmeter ensuring that we have 24.5 volts minimum for a battery start confirmed. We are clear left and right, a loud clear prop to anyone around the aircraft, fuel pump to ON, start switch goes on and immediately the loud electric-like whine and woosh of the compressor of the PT6 comes to life.
A quick check of oil and fuel pressure ensuring ops are normal as you do not want fuel going into the combustion chamber prior to light up. The fuel flow gauge confirm's ZERO, the loud metallic TICK-TICK-TICK of the igniters awaiting the arrival of fuel into the combustion chamber. Back quickly to the Ng gauge or compressor speed gauge, expressed as a %, minimum to introduce fuel into the combustion chamber is 12%. The Ng rises swiftly past 12% and because the higher the compressor RPM, the more smooth the start will be, I let it rise up to 18%. It stabilizes and I smoothly introduce fuel by moving the fuel condition lever from idle cut-off to low idle. A fuel flow indication of around 100pph indicates correctly, the dull woomff of fuel igniting and the immediate smell of burnt jet fuel indicates first stage light-up.
All of your attention turns now to the ITT gauge. The engine spooling up quickly now and a secondary dull woomf and woosh signals second stage light-up and the ITT soars rapidly towards the maximum limits. With one hand on the fuel lever and one hand on the start switch ready for a possible hot-start, you hope and pray that the volatile cocktail of jet-fuel and air stabilizes before it reaches maximum temperature limits, which is 1090C. For 2 seconds on start-up, all of a sudden, the swiftly rising ITT needle stops its ascent and decreases back to a stable 650C. All engine perimeters checked, all stable and you are ready to rock.
Start-switch to off, standby power to armed position, ensure generator is charging the battery, fuel switch to norm and avionics master 1 and 2 both on and you are ready to taxi-out. Get the air conditioning on for your passengers and test the electronic master warning system prior to taxi. All this happening in less than a minute. I cant tell you the smile on my face after that little sequence. Call me easily pleased!
Once started, a turbine is very simple to operate and the caravan is one of the nicest flying aircraft around. A pleasure in all conditions, with its beautifully harmonized controls. It really is a pilots dream machine, incredibly capable. With reverse thrust, huge flaps, de-icing, weather radar and a full auto-pilot it is capable of operating anywhere in almost any weather. I loved my conversion and I can not wait for the opportunity to fly the aircraft operationally in the very near future!
- CaravanPilot.com
No comments:
Post a Comment