Sterling Cessna 180 "restoration" - build blog from Outerzone plan download

[Martin Harris - Moderator]

I tried the suggestion of a 7-up bottle to make the tinted windshield but there wasn’t a quite large enough area without a ridge to form the screen from properly although I managed an interim measure sufficient to take the model to the field to run the engine and pass the club noise and new model checks. 

The weather was a trifle unsuitable for a maiden (I’m hoping to exceed the 1970’s  2 second lifespan by a considerable margin!) with the stiff north easterly wind coming off the woods adjoining the field making take-off and climb outs “interesting” even for tried and tested models, so I chose to exercise my discretion. 

[Martin Harris - Moderator]

While I'm waiting for the wind to drop a little, I decided to do a little titivation so knocked up a basic interior on my 3D printer.

 

                               Fresh off the printer

 

I printed it very thin and it weighs 3/5ths of not a lot...

 

A splodge with a paintbrush and some scraps of Velcro later:

 

I'll need to paint the interior woodwork now!

 

[john stones 1 - Moderator]

His/Her hairs gone Grey, should that tell us something ? ?

[Martin Harris - Moderator]

Oi - I resemble that remark...

[Dad_flyer]

A cockpit that full of oil would turn the pilot grey pretty quickly ?.

[Martin Harris - Moderator]

That's not oil - it's more likely to be pitch...trim runaway...

[Martin Harris - Moderator]

A bit of a mixed report...

 

I looked at the forecast for this afternoon - sunny intervals, fairly windy but straight down our main runway.  I've been itching to give it a go so....

 

It wasn't the perfect day but I gave it a go.  The first attempt got it a couple of feet in the air but I didn't feel happy as it was drifting towards the pits netting and didn't feel quite right so I decided to abort and landed back on the runway

 

I re-checked the wind direction and had another go.  This time, it left the ground but on the climb out to about 10 feet it felt like it was tip stalling but I suspect that I was over controlling in the unexpected turbulence - when I flew my Extra just afterwards it was surprisingly rough.  I've made the rudder hinge on the full size stern post whereas the (single channel) plan shows a very reduced chord and height version of about 1/4 the area of mine - my assumption being that being proportional it would be reasonable.

 

Happily, the untidy "landing" this time only resulted in a broken propeller and plastic wing bolt (nice to see it doing its job) but |I think I'll wait for a more suitable day when I can try out a reduced rudder movement.

[Dad_flyer]

I would count that as mission accomplished. You set out to beat the lifetime of the original. Two flights, each longer than 2 seconds, does that with plenty to spare ?.

[Trevor]

Sounds like a good save Martin, well done! I think that some of these vintage designs do tend to get into a Dutch roll if they fly faster than originally intended. If you have a gyro of some sort to hand it may be worth fitting it while you check it out. If it is Dutch roll then, as I’m sure you know,  reduced dihedral or increased fin area is the recommended remedy.

 

good luck,

 

Trevor

[Danny Fenton]

Well done, it may not have been the result you wanted but it lives to fly another day ?

 

[Dwain Dibley.]

Re-maiden . That's what I did with the Spartan. LOL

 

D.D.

[Martin Harris - Moderator]

Thanks for the kind words gentlemen - as has been mentioned, there was an element of success in achieving the original target of exceeding the original flight time and bringing home a virtually intact model.

 

I'm tending towards the Dutch roll theory - the C of G is well on the safe side and it felt stable in pitch. My first move will be to reduce rudder movement on the aileron stick although it will be useful to leave a reasonable amount on the left stick for ground steering.  The plan showed a rudder of approximately 1/4 of the area of the full size (ignoring the balance tab) for single channel "bang bang" operation and I reasoned that a scale-ish one operating proportionally wouldn't be unfeasible. This may not have been one of my wiser assumptions.

 

Changing the amount of dihedral and/or fin area is rather going against the ethos of the exercise - if going to these lengths I would probably just build an aileron wing with scale dihedral. What was interesting in the original instructions was the advice to climb to at leat 100 feet on the maiden before attempting to use the rudder and even with the original reduced rudder area, they did note that it would be quite responsive under power...  It's a long time since I built anything 3 channel with enhanced dihedral and the rudder movement I've used was based on normal 3 axis controlled models.

 

The order of play is to achieve extended controlled flight and then switch to single channel mode once some appropriate control movements, trim and power settings have been established.

 

Roll on (if it's not an inappropriate term) the next calmish day!

[Martin Harris - Moderator]

Well, it’s taken almost 46 years but I’ve finally flown the Cessna under control and brought it home in one piece. 
 

The wind was a little above forecast but after a couple of slightly crosswind attempts (exaggerated high wing dihedral, no ailerons and crosswinds aren’t a happy mixture) I relocated for an accurately aligned into- wind take off run and she left the ground after a short ground roll and climbed out steadily. 
 

With the dramatically reduced control movements, rudder response was rather muted so I switched to a higher rate (between the two extremes) and it really hit the sweet spot. 
 

Once happy, I switched to Single Channel emulation and threepenny bit turns ensued, proving it was working!  I will need to fine tune the two position throttle as the idle setting was too high and it could do with a little more oomph for the high end.
 

After coming back to 3 channel proportional mode the rudder response seemed a bit lethargic so I decided to land and check for anything coming loose.  As soon as I’d landed I realised that I’d accidentally switched back to low rates while finding the mode switch so all was well.  As I ran out of fuel as I finished taxying back to the pits, landing when I did was not a bad thing in retrospect!

 

As the wind was picking up I decided discretion was the better part of valour and resisted the temptation to fly it again but it shouldn’t be too long before I repeat the exercise. 

[Danny Fenton]

Brilliant well done, that's great news ?

[Martin Harris - Moderator]

Been a bit of a break since the previous post but I’ve flown it a couple of times since and finally have some shots of the 180 in the air, taken by club mate Chris Larkins earlier today.

 

 

 

 

 

 

 

I explored the single channel emulation a little more extensively - interesting but to be honest, I preferred proportional 2 axis control. 

 

 

And a fitting final shot on a lovely  spring day - hoping to enjoy many more such flights. 

[john stones 1 - Moderator]

Cracking view.

[Martin Harris - Moderator]

We're fortunate to have a great site which far sighted members invested in back in 1982...a lot of money at the time which wouldn't pay for 2 years rent these days. It's not the biggest field in the world but it's about 5 miles from home, just far enough from the local village to allow us to operate in reasonable harmony (touching everything wooden in the room!) with terrific views across open countryside...and has the friendliest pub I've ever known, which serves good beer and meals right at the end of the access lane!

[Dwain Dibley.]

Yep !!  That's what it's all about !!

D.D.

[Danny Fenton]

Brilliant Martin, really pleased it outlasted both of our previous attempts. Great pics too.

Cheers

Danny

[Martin Harris - Moderator]

It handles very nicely Danny - and is a very efficient airframe.  It's sad that you never got the chance to explore it in its control line guise. The tank isn't massive and I flew it until empty, about 5 minutes total, on today's last flight - and had trouble losing height on the circuit...no slipping option without ailerons of course - so had a longer walk than anticipated.

 

My first few experiences were unusually tricky with extremely squirrely behaviour on take-off attempts but I've learnt (rediscovered?) that taking off directly into wind and letting the dihedral do the work rather than chasing the wings with the rudder are the keys to success.  Back in the day, hand launches would have been the norm, I'd guess and would have made life with a bang/bang rudder much easier.  Tighter turns on single channel are "interesting" if attempted lower down as the nose drops significantly without elevator compensation and the rate of turn becomes limited, leading to one slight "incursion" of our dead airspace over the car park while experimenting with that mode.  As Safety Officer, I gave myself a stern rebuke and consider myself duly admonished!

 

The Leo 15 is a perfect match, allowing good climb rates and although maybe heavier than the intended .09s and .15s of the period (due to ball races and a much larger silencer) giving the model a C of G significantly further forward than the "about a third wing chord" specified, shows no sign of nose heaviness - with the possible exception of the degree of nose dropping in S/C mode, which is to be expected with rudder only turns anyway - behaviour traditionally used deliberately to build airspeed for initiating S/C aerobatic manoeuvres.  The rigging angles from the plan give a positive climb under power and a nice glide at idle when using simulated quick blip throttle and fixed elevator.

[Martin Harris - Moderator]

Today, I finally got the chance to fly the Cessna in good conditions and really get to know it.  It's actually pretty capable and - as well as looking rather good in the sunshine - a lot more fun than I'd expected.  I finally plucked up courage to test the strength of the wing - I'd seen a few warnings that the structure wasn't all that strong in the centre section and made a few subtle modifications during the build - with some aerobatics, both proportional rudder, elevator and throttle and bang bang rudder and throttle simulated single channel/quick blip operation as per my old McGregor outfit (not actually) used in the spectacular 2 second maiden back in '75.

 

I had a moment of doubt during simulated single channel aerobatics when after winding it up into a spiral dive it took most of the sky to recover but otherwise some of the loops were successful and barrel rolls were quite convincing.  Switching to 3 channel proportional, it did everything I asked of it within the constraints of an aileron-less wing, but I might have to rethink having additional movement on the rudder stick (for positive ground handling - normal flight control is on the "aileron" stick with movement reduced after those initial test flights) as an instinctive rudder correction during a cross wind touch and go as I opened the throttle swung the model through 90 degrees instantaneously...fortunately nicely into the light wind and with space to just carry on with a rather unconventional touch and go.