A Beginners Guide to PSS - Part 3

This months column is the third and final part of my introduction to PSS,. I may if I get time in the future, write some more on the subject and Some of the events attended by myself. I would like to dedicate this months offering to the competitive side of PSS such as it is and hope to encourage more people to have a go these fun and informal gatherings.

PSS Tornado hurtles by...

Most of the PSS events currently run in the UK aren't really competitions; they're more like informal fly-ins. There are a set of PSS competition rules in the BMFA handbook but these have largely fallen into disuse, mainly because of the lack of flying time - driving 150 miles for a single 10-minute flight isn't my idea of fun, and I don't suppose anyone else will be that impressed either.

PSS events are usually a good day out because you get to see other PSS models and talk to other pilots - and a nicer bunch of people you couldn't hope to meet. A complete list of the currently scheduled UK events is normally on the Power Scale Soaring Association website which you will find on the links page.

Wot a nice bunch...

The usual format these days is for everyone to turn up, have a pilots briefing (launching areas, landing areas, etc.) and then fly as much as possible until the end of the afternoon, when any prizes will be presented. The trend is for maximum informality, but some events (e.g. Hole of Horcum) sometimes operate a slot system; you can fly for 10 minutes at a time, and are expected to land when the event organiser blows a whistle/horn to signify the end of the slot. You can then put your name down for the next available slot.

The judging at the Ribble Valley meetings is usually performed by the competition director, but the other events usually operate on the peer-voting principle;

each pilot is given a slip of paper on which he/she is required to write their assessment of the best model in each of the following categories;

a) Best static prop

b) Best flown prop

c) Best static jet

d) Best flown jet

Mig 15-looking for trouble-What a gorgeous backdrop for an event...

Some models of course will require a little assistance...

Naturally, it's considered Bad Form to vote for yourself. The votes are handed in to the organiser at the end of the afternoon, and the prizes are handed out. It's only a bit of fun, the main reason most people turn up is to have a good day's flying and talk to their mates. How you actually assess what's best is a matter for you - there's probably an element of personal preference in there somewhere, but generally speaking the models that get most votes seem to fall into one of the following categories:

a) New

b) Attractive

c) Large

d) Flown so that they don't look like models.

I can't offer any sensible advice on the first three, but I can discuss some guidelines for more scale-like flight; bear in mind that this is just my own opinion, and is no more valid than anyone else's:

a) I think the major thing that destroys the illusion of reality is a model that twitches around in roll; you never see the full size rocking it's wings as it's halfway round a manoeuvre. Granted, there's usually a certain amount of turbulence and you can't do anything about that, but you can keep the thing at a constant bank angle as it tracks around the turn.

There are many designs to choose from in PSS how about a gloucester Javelin?...

or a 104 starfighter...

b) The next worst thing is a model that wobbles up and down in pitch as it flies a nominally straight-and-level path across the front of the slope. Too much elevator movement won't help but the c.g. does need to be in the right place for the model to fly smoothly. Try holding it in a 30-degree dive for a couple of seconds, and then release the stick. The model should pitch up at a few degrees per second - if it pitches up much faster than this, the c.g. needs to come back.

c) Roll rates are important. A jet with powered controls like the Hawk, Hunter or F-86 will be able to generate the maximum useable roll rate of about 200 degrees per second, with a correspondingly snappy start and stop to the manoeuvre, at most airspeeds. A typical WW2 fighter is rather different, having a rather reasonable rate of roll at low speed (80 to 110 deg/sec at less than about 200 mph) but much less at high speed (a bf109E could only manage 11 deg/sec in a 400 mph dive, and the Zero was widely regarded as almost impossible to manoeuvre above about 300 mph).

No it isn't Jon's Twinjet...

That big Lockheed U2 in flight

Control movements are a matter of personal preference, some people fly with very large movements and tiny nudges on the sticks, I have rather less manual dexterity so my elevator and aileron are set up as follows: Ailerons: enough movement to produce the maximum required roll rate at a typical flying speed. Elevator: just enough movement to flare for landing.

I hope this has inspired some of you to come along to a PSS event and have go; it's usually a good laugh and at the very least you get to see a different hill. Many people are concerned these days that they are not good enough flyers to enter competitions or that their building skills do not meet the standards needed.

Remember though that you are possibly the worst judge of your own efforts and others will probably have a better opinion of them. At the end of the day these meetings are all about doing what you enjoy most, and that is flying models. So come along and I'll see you there for a great day out.

Article by Andy Blackburn for Bumpy Green Model Aerodrome
7th May 2002