Polycarbonate or Acrylic?

Over the years, there has been much discussion around the suitability – or otherwise – of polycarbonate (often called by the Lexan brand name) or acrylic (often called plexiglass) for light sport and recreational aircraft windscreens. Of course, as with anything aviation, there are no simple answers as to which material is best. There are pros and cons either way.

Aeroprakt now offers screens using either type of material – 2mm flat sheet polycarbonate, with UV protection and a scratch resistant coating, which is shaped during installation; or 3mm acrylic pre-shaped to fit. Both types of screen do the job and should last many hundreds if not thousands of hours in service. However, there are potential drawbacks and provisos to the installation and maintenance of each type of screen which, if not followed properly can lead to damage, cracking or at worst shattering of the screen.

Arguments in favour of polycarbonate include:
– it is almost indestructible, even in thin gauges; in fact it is a major component of bullet proof glass!
– by any definition, polycarbonate sheet is very flexible and can be formed cold into even fairly complex curves;
– generally, polycarbonate tolerates drill holes and is more ‘workable’ than acrylic.

The downsides of polycarbonate:
– the main drawback to polycarbonate sheet is its susceptibility to damage from gasoline exposure, even small drips can start to destroy the material and lead to cracks, deformation and the characteristic ‘bubbles’ which seem to be inside the sheet, particularly where it is shaped and under stress. The edges of polycarbonate sheet are notably susceptible to this kind of damage, often resulting in edge cracking;
– some other types of chemicals, typically those used in cleaning products (eg ammonia) also cause similar damage to polycarbonate sheet;
– polycarbonate will slowly discolour due to UV light. However, UV coatings can delay this process and it can take at least 10-15 years to occur, especially if the aircraft is kept in a hangar when not in use.

In favour of acrylic screens:
– generally more scratch resistant than polycarbonate sheet, although scratch-resistant coatings on polycarbonate have improved a lot over the last 10 years or so;
– all but the worst scratches on acrylic can usually be polished out;
– acrylic is optically clearer than polycarbonate, with much less distortion, even around curves;
– generally, acrylic screens will tolerate a wider range of chemicals, including gasoline, without serious damage.

The downsides of acrylic screens:
– acrylic is much more brittle than polycarbonate sheet. As a result, more care is needed when installing to ensure the screen doesn’t shatter just as you install that last rivet!
– acrylic needs a wider margin around screw and rivet holes to ensure expansion does not cause cracking through chafing or expansion stress – if badly installed, an acrylic screen can crack due to the hot sun warming a cool screen with not enough clearance around the rivets;
– at least one bird strike on a Foxbat screen ‘bounced’ off a polycarbonate screen; it’s likely an acrylic screen would have shattered. However, a couple of other bird strikes have shattered polycarbonate screens.

Ultimately, the choice is yours. However, Foxbat Australia has taken the view that the thicker acrylic screen offers enough overall benefit to standardise it on all A22 and A32 aircraft supplied new in Australia. These advantages include its better resistance to fuel, less susceptibility to edge cracking and, last but not least, reduced noise in the cabin. The 3mm screen is also available as a retro-fit item on both models of aircraft – it’s relatively quicker to install than the 2mm flat screen but you do need a jig (which can be loaned).

There’s a great Kitplanes Magazine article here, which goes into more detail about both types of material:- http://bit.ly/2NNJ7eE

New Aeroprakt factory website

Aeroprakt has launched its new, modern website incorporating many easy-to-navigate and visually stunning features. It’s a great development from their old website which seems to have been around a long time!

In addition to all the information on the A-32 and A-22 aircraft, and essentials like Service Bulletins, there are many new photos and videos to see. There’s also an interactive map to help you find the country dealer nearest to you.

Some pages – such as ‘History’ are yet to be completed but don’t let that stop you exploring this exciting new site!

You can click here to link directly to the new site in English (you also have Ukrainian and Russian language options): http://aeroprakt.kiev.ua/en/

Dan Johnson tests the A32 Vixxen

Light aviation’s guru blogger Dan Johnson grabbed the opportunity to test fly the newest FAA LSA-approved aircraft, the Aeroprakt A32 Vixxen.

Click the photo above or here to see the article and accompanying video: Dan flies the A32

You can read more – much much more – about all manner of light sport, recreational and ultralight aircraft on Dan’s blog: ByDanJohnson.

A32 Vixxen door latches – safety bulletin

Aeroprakt has issued a safety bulletin covering the door latches on A32 Vixxen aircraft, serial numbers 02-28. Compliance with this bulletin is required before the next flight of the aircraft.

Click here or on the drawing above for a copy of the bulletin: SA-A32-03 Door Latches

Aeroprakt A32 demo flight

Via the cockpit video recorder, follow Yuriy Yakovlyev, A32 designer, Aeroprakt CEO and gold award-winning pilot as he takes the A32 through a demonstration flight routine at the 2017 Krakow Airshow in Poland..

It’s interesting to watch Yuriy’s use of throttle and flap and his control of airspeed throughout the 5-minute routine. This video shows what the A32 can do when flown by an experienced pilot.

However… PLEASE NOTE: most of the manoeuvres in this flight sequence are illegal in this type of aircraft in Australia! DO NOT try this at home – remember, Yuriy has many thousands of hours flying experience, not only in his own Aeroprakt factory aircraft but in many other types too.

As usual, click the picture or on this link to see the video: Yuriy flies the A32 at Krakow, Poland

Aeroprakt A32 crosswind at Tyabb

Crosswind at TyabbYesterday there was a fairly strong and gusty crosswind on Tyabb’s 35/17 runway. The crosswind was made even more tricky as the wind was blowing from the north west over the hills and trees near the airfield, making for very uneven and turbulent conditions.

Quite by chance, Mike Rudd, our video producer, was there trying out a new video camera, capturing a couple of aircraft landing – but due to the conditions, there weren’t many up and about in the skies! However, my colleague Ido Segev was flying an A32 Vixxen demonstration with a prospective owner. (Thanks to Stuart for the loan of his aircraft).

This very short video (click the photo or here to view on YouTube) first shows a landing by a Beech Travelair twin, piloted as it turns out, by Roger Merridew, a very experienced pilot and owner of Lilydale Airfield. He is followed closely by Ido and his passenger (who was sitting in the left seat) in the A32 Vixxen.

It’s interesting to note the different techniques used to land each aircraft in what was a 12-15 knot gusting crosswind. In many ways, as you can see, the A32 Vixxen handles the conditions better than the Travelair. The secret to making a successful crosswind landing in the A32 Vixxen is speed management and the minimal use of flap. The aircraft was down safely and exited at the first cross-taxiway, about 70-75 metres from the threshold of runway 35.

Good demonstration Ido!

PS – the prospective customer placed an order after the flight!

Aeroprakt A32 1,000 nm ferry flight

ido-shaun-at-emeraldMy colleague Ido Segev and his friend Shaun just got home from an almost 1,000 nautical mile ferry flight of a new shiny Ferrari red Aeroprakt A32 Vixxen, registered VH-ACL, to its new owner Will Graham.

The aircraft is fitted with a Dynon SkyView system, including a 2-axis autopilot, transponder and fuel computer. In addition to the standard dual-watch VHF radio, the aircraft also has an 80-channel UHF radio, operating through the headsets.

ido-shaun-ferry-02Their flight took them from Moorabbin Airport, near Melbourne, via Temora and Parkes in New South Wales, to an overnight stop at St George in southern Queensland. Most of the flight was made at 8,500-9,500 feet AGL, which at times translated into a density altitude of over 11,000 feet. Said Ido: “Even at 7,500 feet were were still climbing in excess of 500 feet a minute – not bad with two of us, full fuel, luggage and some spare parts on board.” The next day, the weather wasn’t so kind, with strong headwinds and a 2,000 foot cloud base. Nevertheless they made good time and arrived at Emerald, Queensland, before lunch, after a short wait at Roma while some weather passed through.

Total flight distance was about 950 nautical miles with and average ground speed of slightly over 95 knots. Average fuel burn was a shade under 17 litres an hour. In metric fuel economy terms, that’s about 10.3 litres per 100 kilometres – not bad for an average speed of over 175 kilometres an hour! Ferrari and co, eat your hearts out!