The Affordable Alternatives

Welcome to Zond Aviation

Background:

Mark was unable to fly LAK 17bt enough and at the beginning of the competition, he had only 2 hours on type with virtually no soaring experience. In addition, he had a major instruments problems as all displays were in German. This lead to three competition days scored at zero points, due to the airspace infringements. I have edited the full story in order to be presentable on a web page. For the full and unedited document, feel free to contact Mark or myself.

 Mark’s Story:

Running was different in that the LAK 17bt easily kept up with all the other gliders and in fact seemed better than the ASG29 when flying faster than 200 Km/h. From my competition experience I feel that I spent most of my time trying to fight the glider to perform and thus spent too little time concentrating on the matter on hand – that is racing. In discussion with the other Lithuanian pilot also flying the LAK 17bt , he also felt that you would need at least 100 hours in the glider before you could feel as if you were in full control. The following are areas that I feel are positives and negatives of the glider:

 Finish: The glider is beautifully finished. I feel that there are too many access portals which give an impression of turbulence over the skin even though it is unlikely to affect performance.

Ballast system: I understand that later versions have a direct filling system which would make life easier especially with the outer wing tanks. I found that the outer wing tanks usually had water in them on landing, even if they had been open for over 15 minutes. I think that the reason must be that the vents are placed on the wing section that gives the most lift (also very close to the winglet) and the negative pressure is enough to stop drainage. It might help to move the vents to a place with either neutral or positive pressure in order to expedite drainage.

Trim: The glider trims very nicely and the trim lever lies fairly centrally in all phases of flight.

Thermalling: Apart from the negative things I have mentioned above (not having the right tail ballast—flying too fast (Edited by Daniel)), the LAK 17bt gives a very positive ‘kick’ in the tail when you hit the centre or gust and that is very helpful in centering. I did drop a wing on one occasion when I pulled too tightly in a thermal and the recovery was reassuringly quick and uneventful.

Ventilation: I found that the ventilation was poor on hot days and I checked the flap valve in the nose and believe that it could be easily adjusted to open more fully.

Wheel brake: Excellent. There should probably be a warning in the manual about being careful in applying it too hard. This may be another reason to have a bit more elevator authority to counteract the forward moment on hard braking.

Tail wheel: It spins in certain flap configurations. It was initially disconcerting, but once I worked out what was going on it was little more that just a nuisance. It should be simple to stop this.

Canopy seal: I was disappointed to find the windscreen to be poorly sealed. In my experience most modern manufacturers go to a lot of trouble to seal the canopy in order to maximise performance and minimise noise. 

Other sources of noise: The engine doors were also noisy.  Despite the above problems, the glider was not as noisy as I expected when flying at speeds exceeding 220 km/h.

Instrument panel: I found the design of the instrument panel very attractive and it allowed excellent movement of my long legs. It however is very limited in terms of the space behind it but I don’t think it is a problem with the more compact newer instruments.

Sustainer engine: The engine was powerful enough, not too noisy and started quite easily especially after it had been warmed up by previous use. I am new to operating such an engine and have a problem with the ergonomics of extracting the engine. (Summarised by Daniel : The extraction/retraction system is complicated (ILEC operated) and takes concentration to get it right in a stressful situation (outlandings))

Comfort: I found the LAK 17bt to be the most comfortable glider I have flown and did not feel unduly fatigued even after a long 7 hour task. I would definitely check that the ventilation can be turned up for hotter climates.

Airbrakes: The airbrakes are difficult to manipulate when flying fast. I found short field landings easy to manage especially with the very effective wheel brake.

Flaps: The flap lever is easy to fly with and I like the fact that it needs little flap input over quite a large range of speeds.

Wheel retraction: The mechanism is easy to use and I like the way you can see that the lever is in the correct position by looking at the notch.

Trailer: This was a pleasure to work with.

Rigging: The rigging was not difficult. I don’t like the need for the rigging tool to pullout the safety stop when removing the elevator. It also places another gap on a leading edge, but will definitely result in someone forcing the bolt with an expensive repair.

Mark “Doc” Holiday’s LAK 17bt Experience at EGC2011