Nine Minute Engine Problem

Or…I learnt about flying with a Rotax engine from that. Here we are at Sønderborg in Denmark a couple of years ago, basking in the midday heat. We had flown in from Groningen and were hoping to get all the way to Siljan Air Park in one day.

Flight Plan filed for the leg to Höganãs and aircraft refuelled, we jumped in and made our way to the end of the runway. With the heat, the plan was to climb as quickly as possible into the cooler air at 3000 feet or so…

I had just taken the photo above when we were assaulted by a strange smell and fluid running along the right side of the canopy. Brenda said with admirable calmness “It’s coming in!”

My immediate thought was “OIL LEAK!” so I throttled back and turned back towards the airfield. Checking the temperatures and pressures to confirm, we found that the oil pressure and temperatures were fine, so probably no leak – but the coolant temperature was high. Telling ATC that we had a problem, with no wind they cleared us to land in the opposite direction to our take-off. The Skydemon trace overlaid onto 3D Google Earth shows all nine minutes of the flight:

With the engine at low power the coolant temperature came down quickly, we landed OK and parked up in the same place we had vacated only 20 minutes or so before. After shutting down we pulled the cowlings to have a look. Here Chief Engineer Brenda inspects the coolant system overflow bottle – which was found to have lost some of its fluid.

I had made the rookie mistake of trying to climb quickly to the cooler levels. Full power equalled lots of heat output from the engine, and climb speed meant reduced airflow through the radiator. Combined with the high ambient temperature of midday in a summer heatwave the result was a rapidly rising coolant temp. The boiling coolant had started to expand out of the expansion vent on the top of the expansion bottle, and got sucked through the cowling gap and along the right side of the canopy. Luckily the stream passed over the open air vent, and alerted us by coming into the cockpit with its attendant funky smell.

We inspected the engine as it cooled. An Air Alsie Express engineer wandered over from the hangar to see if we needed any help, so we managed to scrounge some distilled water to replace the missing coolant. Just as a nosebleed always looks worse than it really is, we hadn’t lost very much fluid at all. It only required a “wee sploosh” to get the level back to in between the Min and Max markings on the bottle.

Once the engine had cooled down totally, I started up again while Brenda watched for any obvious leaks (it might not have been just from the overflow bottle), but all was OK. I shut down, we inspected the coolant system very closely and refitted the cowlings. Then we had to go into the terminal building again to refile the flight plan and have another cold drink from the machine.

On our second departure from Sønderborg I throttled back a bit at 500ft and did a long cruise climb up to the cooler levels. The coolant temperature stayed right where it should for the whole flight, and the rest of the trip up Sweden, and back five days later. I learnt about Rotax engines from that…

“Wee sploosh” is a recognised engineering term – Chief Engineer Brenda says so…

Spring Has Sprung

With COVID lockdown due to come to an end, a couple of essential 28-day engine health flights were required to get the aircraft ready for the glorious spring and summer flying season ahead. First up was the Cub:

This time she started right up, and we were soon proceeding in a leisurely manner over the Scottish countryside. This is Kinclaven and the River Tay:

I had decided to go a little further afield than just the very local area, so we set off into Fife, aiming for the airfield at Crail on the easternmost tip of the county. It was a lovely day so obviously a selfie was required:

Note the blue badge above my right shoulder, just in front of the speaker? That is to commemorate the L-Birds to Normandy event in 2019, where former military Cubs converged in France to mark the 75th anniversary of D-Day. You can make out the map of the Normandy coastline on the badge. The previous owner Richard took the aircraft to the event, and it’s a trip that we would like to do in the future. It will take a long time at 70 knots, but that’s vintage aircraft flying for you.

Here we are with a 63 knot groundspeed making our way back from Crail…

Behind the aircraft on the map view you can make out part of the circular symbol for Kingsmuir airfield. Sincere apologies to the aeromodeller who picked up his aircraft and cleared the runway as we approached the overhead, just to see us putter off into the distance with no intention of landing. Sorry! I made sure to give it a slightly wider berth on the way back, but the radio control flyer’s car had gone by then.

Landing back at Perth in calm winds, I jumped out and went for a pee. The weather was so nice I decided to go up again, this time just locally to the north. Here’s the confluence of the Tay and the Isla again:

Last time we saw it, it had those great Kelvin-Heimholz instabilities:

The high wing and opening windows are great for photography:

…but the fuel doesn’t last forever, so with the float and wire gauge bobbing down towards the bottom, it was time to land. The engine had a good run, and with the annual due at the end of April, a summer of fun awaits:

I got home to find a package had arrived with two decals from the 79th Infantry Division. These will go on the cowling. They may cause a little confusion to the experts as the Cross of Lorraine was also the symbol of the Free French forces, but in this case it is the badge of the 79th, commemorating the unit’s area of operations in the First World War:

Next up, the RV. Another day, but still lovely weather:

I had included aerobatics on the insurance for this year’s renewal, surprisingly with no increase in premium. So it would be silly not to…

As my RAF friend Tony said: “Why do you have the map on the ceiling?”

A summer of fun awaits…virus permitting.

Winter Wonderland

Taken from the Cub during the January engine health flight. Not much writing here, just pictures of Perthshire in winter. Apologies for some of the quality…I’m still getting used to the camera and I was freezing my butt off with the window open, an extra source of camera shake.

Swans on frozen loch
Strange fields
Hillside
Long shadows
Lines
Lines and circle
Snow patches
Taller crop above the snow?
Winter farm. Farmers never stop…
Spindly trees
Hillside tracks
Wooded hillside
Future Christmas trees?
Airfield?

This last weird rounded field surrounded by trees is the sort of place the Cub could have operated from during WW2. Measuring on Google Maps shows it to be about 750m long, more than plenty. It even has a barn top left, probably with enough room for a Cub. Maybe it’s for sale.

“We Bought an Airfield!” – new post coming soon…?

Cub IFR

Also known as “Engine Health (2)” – this time it was the Cub’s turn. It can be a bit of a pain as the aircraft is tucked away in the hangar behind a Cessna 182 which takes a bit of muscle power to move out of the way:

Fortunately there were a few others at the hangar that day and we helped each other wheel our aircraft out onto the icy apron. It was so cold that Robert had a hairdryer in the RV9A’s engine compartment to pre-warm the oil; I had refitted the Cub’s battery after charging at home in order to have as much power as possible to help get the engine started.

The Cub came out with its nose in the air, almost like it was saying “This is nothing, you should have seen winter ’44! Let’s go!” – but then it was reluctant to start. Eventually after a secret combination of primer, mixture setting and throttle position I got it started. I say secret because I have forgotten what I did, and I’ll have to experiment all over again next time. Maybe I’ll just put a hair dryer in the engine compartment to pre-warm the engine? It worked for Robert.

Soon we were off and heading northwest to follow the A9 for a bit:

In the lower parts of Perthshire there was not too much snow lying around:

But the further north we travelled the whiter the ground became…

Northwest of Bankfoot there was some low cloud around. It felt a bit like that scene from “The Battle of the Bulge” movie where the spotter aircraft was looking for enemy forces in the fog. No Tigers spotted here:

What unseen enemy forces lurk in this little Belgian village? Are those tank tracks coming out towards the woods?

Vehicle tracks and shell craters in this field?

Since we didn’t see any enemy, we flew up the A9 to the Dalguise area before turning back southwards. For the non-aviators reading this, IFR should stand for Instrument Flight Rules, like airliners way up high, using beacons, waypoints and designated routes to get where they are going under the watchful eye of Air Traffic Control.

In the case of the Cub, IFR stands for I Follow Railways. Here we are following the Inverness to Perth line, with the A9 trunk road and the River Tay running along the valley as well.

IFR = I Follow Roads / Rivers / Railways (delete as applicable)

That old IFR joke has been around since Pontius was a pilot. So has the Pontius one…

Here’s Dunkeld from the north:

After Dunkeld we wandered all over the countryside with the window open taking photos. There will be another picture post soon with the best of those.

After 50 minutes the weather was slowly starting to deteriorate so it was time to head back to the barn…

Engine run and oil warmed up, photos taken and pilot frozen…mission accomplished!

Can’t wait for more normal times and warmer weather and longer adventures. In the meantime, we can dream. The Buck brothers flew a Cub all the way from New Jersey to California when they were 17 and 15 – Flight of Passage is the story of that trip, and much more.

A great book…well worth a read.

Engine Health

Lockdown again. Not much flying going on outside of work, but engine health flights are still classed as essential so every four weeks I can go for a blast. The purpose is to get the oil temperature up to the range where any water condensation inside the engine is well and truly boiled off. If left to fester, the water can start an unseen corrosion process inside the crankcase. This is obviously not a good thing.

A ground run won’t cut it; The best way to get the oil temperature up is to go flying. The Cub’s fuel tank was more or less empty but the RV6 still had 45 litres of fuel onboard, so we went for a zoom around at 140kt…

Routing south from Perth following the M90 motorway through the hills towards Loch Leven, just visible in the distance:

There were a few other aircraft about, all doing the same thing. The traffic display on Skydemon showed one ahead of us descending into Balado airfield. If it had been closer it would have shown on the dark traffic screen bottom right as well as on the map:

There was a target for the flight. Renowned aircraft photographer Wallace had been stuck at home and was going stir crazy, resorting to taking photos of high flying cargo planes with a very long lens. I thought I would go and orbit his house and give him something different to shoot. He lives in among the houses at the T-junction top right of the photo:

Here’s the Skydemon trace imported into Google Earth in 3D. One orbit of the target before climbing away and heading back towards Perth.

This Google Earth 3D trace has become my new toy. It’s fascinating to go back through the logs and see what we did. It’s accurate enough to show the route of the works helicopter vacating the runway and following the taxiway before landing on the helipad.

We scrutinised the logs for the 2018 Sweden trip and were able to see the point where I vigorously manoeuvred the aircraft to avoid conflicting traffic. This really close threat turned out to be a Luftwaffe Transall transport aircraft about five miles off. Plenty of time for us to get out of the way. The “smartly executed deconfliction manoeuvre” shows as a little kink in the trace.

After Wallace’s house we flew back towards the airfield, passing to the west of the field…

…before coming back in for an overhead rejoin. Here you can see the trace coming in from the top of the picture at 2000ft, then descending to 1000ft on the dead side to the south of runway 27 and joining the circuit on crosswind. Downwind at 1000ft before descending on base leg and final to land. The bit going left is the take off from earlier:

So, the engine had a good run and the pilot had a good workout. The landing was acceptable too. I think flying the Cub has honed my tail wheel skills.

Wallace missed the flypast, but the RV grin is back. We’ll count that one as a success:

Later at home, I was thinking about the Google 3D thing, and had a look at the Christmas tree effort on 24 Dec which came out all wrong on FlightRadar. It’s awesome in 3D…

Flushed with success, plans are afoot. The Easter Bunny is next….

New Year – Old Map

An interesting discovery at a local antique shop – an old RAF chart. Thanks to Helen for the find… her husband Darren works as a paramedic on the helicopter.

Its even of our own area! In good condition, there are some lines drawn on it in pencil so has been used for flight planning at least…

Searching for clues as to the map’s age, it says 1934 on the compass variation rose, although these are not usually changed every year, hence the “annual change” note:

In those times the city of Glasgow was a lot smaller than it is today:

The red dots are airfields; Abbotsinch is now Glasgow Airport and Renfrew is now under houses and part of the M8 motorway. A closer look at the Dundee area provides a clue:

Our old friend Tealing airfield to the north of Dundee is not shown on the map, and looking at Fife Ness the airfield at Crail is missing too:

Tealing airfield was built during the early 1940s, during the massive expansion brought about by the Second World War. Crail was built in 1918 but deactivated after World War One then reactivated in 1939. So now we have narrowed the map’s age range to somewhere between 1934 and 1939.

The Firth of Forth shows a large restricted area over the naval base at Rosyth, with a bombing range off Inverkeithing. The airfield at Turnhouse to the south of the Forth Bridge (it was the only bridge there at the time – no need to call it the Forth Rail Bridge) has now evolved into Edinburgh Airport. The old RAF Turnhouse has long been demolished to make way for the cargo apron and handling facilities…

Not everything suffered the fate of RAF Turnhouse, there is still a lot of old military stuff dotted around the landscape. Our chart shows a restricted area in a bend of the Forth to the south of Alloa:

Here’s the same area today. The ammunition storage bunkers are still visible, revealing the reason for a restricted area. Don’t want any student pilots accidentally bombing the place…

Our home base of Perth opened in 1936, so we have got it down to a three year period between ’36 and ’39 now. The airfield elevation is shown as 390ft above sea level. Nowadays it is published as 397 feet, so either the ground has risen 7 feet or surveying accuracy is better these days.

A close inspection of the notes around the edge of the map reveals the truth! In very small text is written:

AIR INFORMATION CORRECT TO NOTICE TO AIRMEN NUMBER [1937] 102

Interestingly the notes also state that obstructions are shown if they are over 200 feet (60 metres) above ground level – so metres were in use as a unit even then.

In 1937 there was a bombing range out at the Isle of May in the Forth:

Compare with 2021. Now 84 years later it is a bird sanctuary:

David Attenborough would approve!

I’ve actually flown the Police helicopter in to the island, but that’s a story for another time…

Aerial Photo Dump

Some extra photos to make those massive subscription fees worthwhile. Remember you get what you pay for…

Whilst trying to draw the Christmas tree on Flightradar24, we had to climb quite high to ensure coverage. You’ll remember that it didn’t quite work out. Here are a few pics from way up high, to the north of the airfield:

And here’s one from slightly lower, on the way back in. The River Tay winding its way south towards Perth with its own ribbon of mist:

A couple of days previously the Tay was a little foggier. Here’s the whole valley filled up from Dalguise to Pitlochry, north of Dunkeld:

While down at Perth there was no fog at all. This is the tidal bit of the river, as it flows from right to left towards the Tay estuary and the North Sea. Maybe the saltiness of the tidal bit has an influence on fog formation…?

I like the rather cool shadows of the Friarton Bridge pillars. Low winter sun is great for long shadows:

Final photo, this was taken from the Cub on the Christmas Day flight. Before we joined up with Aaron in the Super Cub for the formation photos, I was looking down on these woods and wondering what the aircraft had been doing on Christmas Day 1944…had it been in the Battle of the Bulge in the Ardennes?

A little research uncovered that the US Army’s 79th Infantry Division, to which this aircraft 330244 was assigned, was in Alsace. They were holding a defensive line along the Lauter River, at Wissembourg. Probably with crappy weather. Luckily our weather was nice…

Christmas Cub Combo

A new Christmas tradition…I took the “World’s Coolest Copilot” flying in the Cub on the morning of 25 December. Just tootling around, enjoying the views and taking selfies (note my Christmas jumper!)…

…when who should pop up on the radio, none other than young Aaron, who was out and about in the Perth based Super Cub. Time for some impromptu formation flying! We joined up on the Super Cub and took a photo of him:

…while he took photos of us. Note the flaps down on the Super Cub so that we could keep up…Aaron said it could have been the world’s slowest formation!

We slid over to the other side for a different angle and more of the “you take photos of me and I’ll take photos of you” thing…

Note in the Super Cub the solo pilot sits in the front unlike the L4. Piper Aircraft removed the fuel tank in front of the cockpit and put the fuel up in the wings, which sorted out the centre of gravity issues. It means the Super Cub pilot can actually SEE the instruments, unlike me as my view was blocked by Rory in the front seat.

We stayed in formation all the way back to the airfield before splitting up for separate landings, us on runway 21 and Aaron on runway 27. The wind was all over the place and couldn’t decide which runway to blow down, so we used both.

Brenda snapped us as we flew over Wolfhill:

Back on the ground. You can see the family resemblance:

And thus a new tradition is born…Christmas morning Cub flight with the added bonus of some formation flying and photos thrown in.

It turned out quite nicely.

Unlike my attempt at drawing a Flightradar24 Christmas tree the day before using the RV6. I had just changed the oil, cleaned the fuselage, replaced a couple of tie-wraps and lubricated all the hinges so there was an excuse to go for a Christmas Eve flight.

The flight log on Skydemon shows the finished result:

…whereas the Flightradar24 trace is not so good. Over the hills FR24 reception can be poor and the 24th was no exception. It came out looking like a squirrel or an Easter Island stone head with something sticking out of his neck – definitely not a Christmas tree to be proud of.

Ah well, you can’t win them all. At least we had fun. Merry Christmas and Happy New Year to both my readers! Onwards to 2021…maybe the virus will let us fly further afield. Let’s hope.

Speed

This is the RV6 downhill from 8000ft with a hefty tailwind:

And it looks even better on Flightradar24, which usually has some innaccuracies thrown in…

Sometimes after tootling around in a Cub at 70 knots you get the urge to go fast. It should be called the “need for speed.”

Cool phrase. They should use it in a film.