My friend, fellow pilot and blogger Chris finally completed his Arrow rating and enthusiastically invited me to join him on a "quick blat" over the countryside to somewhere and back. Of course I accepted, and on an impulse asked Chris if another friend, pilot and fellow blogger Aaron could come along. Chris didn't mind, so I send Aaron an invite and after not being sure he turned up at the Aero Club before Chris had arrived!
We backed the plane out of its hangar just as Chris arrived. After a brief discussion and a look skywards our intended trip to Matamata was out and a trip to Rotorua was envisioned. Chris could only afford a short trip but Aaron (who is also Arrow rated) offered to fly the return leg. So after getting the weather information for Rotorua we clambered aboard and took off.
The weather in Hamilton was calm with a light easterly breeze. Upon contact with Hamilton Tower we were instructed to use Grass 07 as it was into wind, but the Arrow with 3 of us aboard would probably be better off using the tarmac runway, so Chris requested it and we were recleared to use that.
Once airborne it became apparent that our intended destination was the right choice, as our visibility east was excellent, whereas to the north and west it wasn't looking so great. We climbed to 2500, then eventually 3000 and headed over the Mamaku hills into the Rotorua caldera. We were cleared to join right base for runway 18 (something I have never done on my trips to Rotorua), I was sitting in the right hand seat and got to appreciate first hand the forthought and planning required that goes into managing a retractable CSU (constant speed unit) equipped aircraft in such a way as to arrive at the threshold of the runway at the right airspeed and engine/prop settings.
For one, the Arrow slows down tremendously when you lower the gear, just backing off the throttle and lowering flaps won't slow it down significantly, indeed in most retractables the gear down speed is higher than the max flap extension speed for that reason.
Then there is managing the engine. A CSU planes propeller has variable pitch blades. In simple terms you can vary the angle the blade meets the oncoming air in order to keep it operating within its most efficient operating speed. The best analogy I can find is a cars gear box. Different gears help keep the engine operating within its most efficient speeds regardless of how fast the tyres are turning. Once of the side effects of a CSU is that during a descent you have to slowly reduce power so that the engine doesn't shock cool itself. In the fixed pitch planes I fly if you reduce power the propeller rpm decreases and this lessens the cooling effect. In a CSU plane the propellor governor will attempt to maintain the propellors rpm which you set independently of the engine power. This is where things can go horribly wrong if you don't treat the engine or propeller controls with proper care.
Confused? I admit it still does my head in when I read what I just typed, but after seeing the system in action its beginning to make sense to me.
Chris did a fantastic job of landing us in Rotorua and we parked up and went for lunch at the cafe in the Rotorua Airport Terminal.
Over our food we mused about our return trip. At some point the subject of what was around Rotorua was raised since Aaron wanted to not take a direct return route back to Hamilton. I said we could go have a look at Mount Tarawera, and then someone mentioned Whakatane. Since none of us had ever been there we decided to go and have a look. With Aaron at the controls of DQV and after a short wait on the ground we took off and headed east over Lake Tarawera towards the volcano itself.
Mount Tarawera was simply amazing. Its hard to believe that the huge fissure below us used to be filled with rocks and covered in vegetation shortly before it all blew itself to all points of the compass in 1886.
From there we flew over Kawerau township and onwards to the coast, where the township of Whakatane lies. About 3nm west up the coast is the airfield and we made a nice landing which Chris using my camera did a great job of capturing on film.
We landed and visited the folks at Air Discovery who like any aviation people you meet were very nice and made us feel welcome. After a short chat we refuelled DQV and took off for Hamilton. Aaron requested and was cleared to climb to 5500 feet VFR through controlled airspace and we cruised for 25 minutes at altitude while we watched patchy clouds whizz past below us.
Aaron started our descent, and I noted that we were going faster than I have ever been in a single engined prop driven aircraft. Chris managed to snap a photograph of the DME showing our ground speed of 155 knots (it had been as high as 157). Just so you know, the figure on the left says 15.5 nautical miles to Hamilton, the middle one 155 knots (approx 295 km/h) ground speed and on the right 6 minutes estimated time to reach Hamilton based on current velocity.
Aaron eventually got us into Hamilton airspace and back on the ground and in next to no time we were putting DQV back in its hangar and making our separate ways home. I was still in relative disbelief that I had covered so much territory in such a short time but thats the way flying shrinks the world.