Shadow Migration

Having finally found a hangar only 40mins drive from home, I flew my CFM ‘Shadow’ microlight from Manapouri down to a farm strip at Otautau.

After pre-flight checks and fuelling up at Fiordland Aero Club’s hangar, I took off and headed south-east. En-route flying conditions were very pleasant with a 10 knot easterly wind @ 2000 ft. Some low cloud in the valleys, but always a clear path towards Otautau. 

Since it was a lovely morning, I flew over Lake Manapouri, around the Monowai basin and wombled through the Twinlaw  hills, before descending to the farmland. At cruise speed, I covered 107km in an hour’s flight. 

The farm strip at Otautau is only 280m long, so first I did a low pass to check it out. Nearly calm at ground level. My landing was pretty average, but the Shadow pulled up with 100m to spare. I’ll need to practice accurate approaches.

Video, sound and GPS data was recorded on a Sony HDR-AS200V action camera.

This camera has WiFi, so I could remotely control the camera settings, and Start/Stop filming, with the live-view app on my iPhone.

The removeable Li-ion battery easily coped with more than an hour of Full HD video recording, with both the WiFi and GPS running.

A few days later, I edited the video using Garmin “VIRB Edit”. This free software allowed me to overlay the camera’s GPS track, speed, course, distance, etc onto the video clip.

Eggshell

Eggshell ‘bits’ were my thoughts as a pilot from further north handed over his lightweight carbon-fibre cowling for repair.

“Can you fix it?” was his question. The air intake was obviously smashed. Fortunately, he had all the broken pieces, so I’d be able to re-create the original shape. 

The related stress cracks were relatively easy to trace and no problem to fix. 

In addition, the exhaust pipes and muffler had been rubbing on the cowling. We found charred carbon laminate under the ‘heat proof’ shields. So more clearance between hot metal and cowling was required.

“Of course I can,” I replied after quickly running thru the possible repair scenarios in my mind. I was very conscious of the need to do a professional repair restoring strength and flexibility, but with no weight increase. “And fix the exhaust problems at the same time.”

First task was to carefully re-create the missing air intake shape from all the broken pieces. A bit like gluing a broken eggshell together. Humpty Dumpty all over again. 

To increase the air gap near hot exhaust parts, the air outlet was widened and a strategic ‘bulge’ was added.

This new cowling shape was filled, faired, surface primed, spot-filled, pinhole-filled, etc to get the shape correct and the surface smooth. Then waxed and sprayed with release agent. 

At this stage, I made a temporary fibreglass part-mould of the lower cowling. 

The lower cowling was cut back and prepped, before the part-mould was mated with it.

I laid-up carbon fabric to create a new air intake, wider air outlet and an exhaust ‘bulge’. Final job was to fill and prime the outside ready for painting.

The rebuilt cowling is as strong and lightweight as original. But with better exhaust clearance. I even incorporated a more sturdy landing light mount.

In the Basin

I took the opportunity to spend a weekend at Manapouri flying my recently-restored 1988 Shadow microlight aircraft. Beautiful smooth conditions, although the air was very cold.. 

Enjoy the short video that i took with my mobile phone, while flying near a tiny settlement called “The Key”.

The Te Anau/Manapouri basin is about 600ft (200m) ASL and surrounded by high mountains. Although it can get gusty NW winds, particularly in spring, the basin is pretty sheltered from bad weather. Nicest flying is typically in autumn and winter when air is cooler and still. In mid-summer, we’ve had some neat flights between 7 – 10pm in evening. 

The Fiordland mountains lie to the west of two stunning lakes (L Te Anau + L Manapouri). Aside from the developed farmland, from the air you appreciate the many tiny lakes, wetlands, streams, rock outcrops and other interesting landforms. 

I never tire of flying in this area. No airspace restrictions below 28,500ft, and only 1 commercial flight a week into Te Anau Airport, so I can relax.

I’m trying different intercom systems in an attempt to increase clarity of radio comms. Need to reduce engine noise and electrical static.

Best option was the PS Engineering “Aerocom 3” intercom, but the Shadow guys in UK enthused about the Microavionics radio interface and ANR headsets, so I’ll probably buy that.

Yah. I’m finally flying again!

Over Manapouri township

I travelled back up to Manapouri Airport to do some familiarisation in the Shadow microlight. Two days of near calm weather – perfect for me. Under Murray’s supervision, I did lots of taxying practice, and then some short hops just above the grass runway.

Then it was time to take-off. The Shadow climbed surprisingly steeply at 50kt, as I tried to keep it below the ‘flap’ speed. Landing is easier than I expected. 

I did 5 flights in just over 24 hours, so I was stoked.  After lots of circuits, I’m learning to control my speed on approach.

A new spring on the elevator trim tab, means that the Shadow will now climb ‘hands-free’ at 60kt airspeed and it can be trimmed to fly straight and level by itself. It still needs further fine-tuning, so it will hold a 50kt approach speed. 

At the end of the second day, Murray suggested that I go for a “tiki tour” of the district. I headed south-west past the little town of Manapouri, then followed the Waiau River down to the diversion weir. A left turn took me up the Mararoa River for a few km, then I headed back west. It wasn’t long before I was calling “Kilo Lima Hotel joining right base for Runway 32”. Very satisfying feeling to have re-built and now flown this aircraft.r

Into the Blue

Sunday started as a dreary rain day. I beavered away at Manapouri Airport doing yet another pitch change to the prop, as well as cleaning the brake shoes/drums and making a larger elevator trim tab for the Shadow B-D microlight aircraft. 

By mid-afternoon the rain had cleared. Murray Hagen declared that he would do some test flights. Having flown hundreds of hours in these machines, he was the best person to fly it for the first time since it’s restoration.

After a few long hops up and down the runway, Murray was off around the circuit. After this initial flight, we increased the prop pitch again.

Late in the day, Murray headed out for a final flight. The Shadow looked great in the air and got round the circuit pretty quickly. 

By this stage, Murray’s smile was very wide, “It’s a fun little aircraft to fly. I like it.” 

We ran out of time for me to do more than some taxi runs, so I’m itching to return to fly the Shadow soon. 

A long project with a successful conclusion. Thanks, Murray, for your help and encouragement.

Back story:

Murray and his friend built two CFM “Shadow” kits (ZK-KLH and ZK-TTE) in late 1988 in his farm woolshed at Pukemaori in southern New Zealand. Both microlights first flew in 1989 fitted with Rotax 532 water-cooled engines, the most powerful Rotax two-stroke engine at the time. 

Over the next few years, Murray flew ZK-KLH to lots of places in the South Island, until in 1995 it was damaged in a landing accident. Later he re-built the wings of crash-damaged ZK-MAX, so he is very familiar with the inner workings of the Shadow.

Fast taxi ride

Another weekend up at Manapouri Airport getting the Shadow B-D microlight aircraft ready for flight. 

This time, the weather was calm and fine.  It was ideal for Murray Hagen, the RAANZ test pilot, to carry out high speed taxi tests and short hops. 

Murray was pleased with the handling of the Shadow. He found that the right brake wasn’t working and the elevator trim tab needed adjustment, so I had some work to do overnight. 

He also wanted more pitch on the new Thompson wooden prop to reduce maximum static RPM. During the day, we kept tweaking the pitch, gradually increasing it to 19 degrees (@ 75% diameter). This process was made much easier by the nifty “Clinometer” app on my mobile phone.  

A significant change from last week, was to add a third radiator to keep the engine cool during the ground runs and taxi tests. The twin ‘tall’ radiators only work effectively when in flight, so with the 30 plus degree temperatures that Southland has been having, the Rotax 582 was having trouble keeping cool.

Gentlemen, start your engines

Last important job is to assemble and pitch the laminated wooden prop. This work of art was beautifully crafted by Brent Thompson. It uses the Precision Prop hardware, but he optimised its scimitar blade shape for the Shadow 582. 

At last, everything is bolted, screwed, glued or wired onto the Shadow microlight. Oil and fuel are in their respective tanks. 

Right, no more procrastinating. Just get on with the engine start. OK, roll the Shadow outside.  Malcolm and George appear like magic and offer encouragement.  Tie the aircraft to a couple of fence posts. 

Bit of mild panic, while the ignition key is searched for! Subconsciously delay a bit longer, by checking a few more bits and pieces. OK, let’s do it. 

After a few pulls, the Rotax 582 fires up easily. A huge relief after all the effort to get to this stage.

Over the next few minutes, we check things over.

  • tacho is reading 5000rpm at fast idle.*
  • handheld Icom A24 VHF radio works well
  • ancient Comtronics intercom has ‘packed a sad’
  • fuel and coolant temp gauges function
  • no response from EGT gauge ** 
  • plunger primer on the dash leaks fuel *^*

Then it’s switch off, push back and go home. It’s been a long hot 4 days.

*Next day my tacho reads only 1000rpm at idle, so it’s clearly a dodgy unit. We temporarily solve the problem by swapping it with the tacho from Murray’s 582 Thruster.

** Reversing polarity of EGT sender wires solves this issue.

*** Tossed out the plunger primer. Too scary to have fuel dripping out!

Final assembly

My wife and I, assisted by Malcolm Swanson, unloaded the Shadow microlight at the Fiordland Aero Club’s hangar at Manapouri Airport.

 

Over the next few days, I worked on installing the gearbox, radiators, carbs, etc.  My wife helped by gluing the blue closed-cell foam foam padding onto the seat bases/backrests, securing the electrical wiring inside the cockpit and applying the vinyl labels to the instrument panel.

Coming home

Nearly 8 years apart, both these photos are taken at Murray Hagen’s home near Manapouri. 

Murray and his mate, Danie Gouws, built two Shadow B-D kits in his large shearing shed. Murray’s Shadow microlight aircraft first flew in 1989 as ZK-KLH. while Danie’s plane was registered as ZK-TTE (after Tuatapere, the nearest town)

So here it is, the same Shadow, but considerably restored and improved.  Almost everything has been dismantled and re-assembled, with repairs as necessary.

The ‘points’ ignition Rotax 532 has been replaced by a new Rotax 582 with dual CDI system. Larger radiators for better cooling.  Larger footwell for rear passenger. Landing gear uprated from 395kg to 450kg. Extra side windows.

Round ’em up. Move ’em out.

Immediately after our Christmas and New Year holiday with our family at Lake Manapouri, I headed back home to Invercargill.

The aim was to prepare the Shadow for transport 150km to the Manapouri Airport for final assembly, engine start and test flying.

My son patiently fitted the various sensors to the engine and connected a myriad of coloured wires up to the voltage regulator and/or the wiring loom.

I concentrated on miscellaneous tasks, such as fitting seat belts, setting up the pull-start system, mounting the oil injection tank and fabricating a horizontal fuel pump mount.  I also checked the operation of coolant temp sender, thermostat and gauge, and the fuel sender and its gauge. 

Finally the Shadow was loaded onto our yacht trailer for the trip back inland to Manapouri.