water Ballast

[Geoff Gaddes]

Hi
Does any body know if the ASW15a can be modified to carry water bags??
I flew my friends std Cirrus last weekend and did 300 km, I had 50l water on and found it to be a big help in the rough conditions last sunday!!!

[Johan van Ravenzwaaij]

I don't think so. The undercarriage of the A version is not designed for the additional weight.
I still have to fix mine, they say a 15 flies much better with some water. Hmm, nice job for a rainy day...

Post edited by: Johan, at: 2008/05/07 16:30

[Joshy]

Don´t agree.
The 15 get´s a little bit faster.
But only nessesary on windy days.

I have water in my 15.
But don´t use it anymore.
Too much work for fuelling.
And climbs much better when empty.

[Johan van Ravenzwaaij]

Hi Joshy,

Long time, no "see".

Should I really not bother fixing my water ballast system, since there is little or no benefit from it?

It's strange, some time ago I met a guy who had a ASW15 in the past and he said that a 15 handles and flies better with some water ballast.

Other owners, please share your experience!

[Will Ellis]

I fly mine with around 50 litres and the difference is amazing. It cruises very nicely at 65 to 75 knots and still climbs well. It improves the performance at 65+ knots to be significantly better than a dry asw19, as i have tried this. I have electric dump valves on mine as the original ones were fiddly and time consuming to rig and fill.

[Johan van Ravenzwaaij]

Will Ellis wrote:

I fly mine with around 50 litres and the difference is amazing. It cruises very nicely at 65 to 75 knots and still climbs well. It improves the performance at 65+ knots to be significantly better than a dry asw19, as i have tried this.

That sounds promising; the asw15 is not so good at higher speeds:(

I have electric dump valves on mine as the original ones were fiddly and time consuming to rig and fill.

Do you have pictures of you system. I am very interested since I have to restore my water ballast system.

[Will Ellis]

next time i go to the club i will take some pictures, the valves are high flow 12v solenoid valves and are available from a company called PVL in the uk. I will try to find the part numbers if you are interested.

[Johan van Ravenzwaaij]

Hmm, you got me thinking about those electric valves. What happens on a low battery situation? Do they open? I guess it's not a good plan to land with water...

[Will Ellis]

You are correct to think about those sorts of issues. I spent a long time weighing up the pros and cons of the various options.

-max landing weight of my 15 is 898lbs which would permit landing with some water on board
-if my batteries went flat so that I was unable to dump my water, an early decision must be made to choose a larger/firmer field
-conveniently the valves I am using make a loud clunk sound as they open so it is obvious if they have failed (very unlikely) or the battery is not supplying voltage
-I have twin batteries and can select which instruments and valves use which, depending on the voltmeter reading
-I chose a separate valve for each bag although two shared valves for both bags was an option, but this was discarded due to potential cross feed in a partially filled state
-the flow rate available from ‘normal’ sized valves is poor, so very large 20mm orifice sized valves were used, and these draw 1 amp each (x2)

In practice the system works very well and even after long 6 hour plus flights with all the instruments and a pda/logger, I have not had any problem dumping (although there is always about 4-5 litres left in each bag which dribble out after landing).

[Johan van Ravenzwaaij]

Quite nifty those valves.  B)

I am still very interested in pictures of those valves. My cables system is for the biggest part destroyed, so electric valves looks like a good option for restoration.

[Will Ellis]

Here are some pics  

Post edited by: Johan, at: 2008/06/11 15:14

Post edited by: willellis84, at: 2008/06/14 06:11

[Johan van Ravenzwaaij]

That's looking good!

[Will Ellis]

smaller pics

[Will Ellis]

the valves

[Will Ellis]

the conectors