Houston JS1c crash ONLY (not in any way about a Puchaczs, or anything else!)

That's crazy. Well, here is to those daring test pilots!

That said, I just learned first hand that a modern glider is capable of losing significant wing water in flight. I visited the 2014 Canadian Nationals this summer was shocked to learn that a brand new ASG-29 returned to the airport with a bit of a surprise. The cockpit was half full of water upon landing. The pilot/owner could not be sure what had happened or how. Was it the fuselage tank or the wing, etc? We suggested that he put the wings up on horses and refill it (before attempting to fly again). He did and sure enough one of the wings leaked, alot! The inboard tank seal (a 3x4 panel on the very inboard part of the wing thru which the ballast dump valve control rod runs) somehow failed during the flight.

So, the wing water tank had definitely been draining into the cockpit at some rate during flight. Additional water was likely draining out the gap between the wing and the fuselage as well (depends on the tapes ability to withstand the water I suppose). How much total water that was out of that wing we will never know. It certainly was possible that the leak was large enough for the glider to have lost all of the water in that one wing. Scary, scary stuff.

I sure hope that scenario never happens to me (or anyone else). That said, I feel better knowing the manufactures are testing that scenario for us. Are all manufactures testing for spin recovery with a full and empty wing? I never would have imagined that that condition could be recoverable. I am impressed that the JS1 (or anything else) could pass that test albeit with a test pilot who knows that one wing is indeed empty (and which wing that is)......

Does anyone know what failures are possible (or that have happened or are known) with other manufactures wing water systems?

This is a very interesting side topic actually. No this does not mean that Punchaz comments are back on the table again ;-)!

Thanks in advance.

On Sunday, July 20, 2014 10:31:41 PM UTC-4, wrote:
Yes, it's been done before. There's a great story about the Schweizer 1-35

flight test with one tank full and the other empty. Bernie Carras (who

was the corporate test pilot for a long time) had a hard time getting

the spin to break. It finally recovered fairly low, and he landed the

plane. He gave the plane a few extra kicks once he got out, just for

good measure!



Matt

On Sunday, July 20, 2014 8:53:12 PM UTC-7, Sean Fidler wrote:

Does anyone know what failures are possible (or that have happened or are known) with other manufactures wing water systems?


My very first contest flight in an LS-3 - at Ionia.

I was climbing in a thermal - as I recall it was right after going through the start gate. I heard they "glug, glug, glug" sound. Looking over my right shoulder I saw a waterfall cascading off the right wing spar. I had failed to burn the wing bag adequately and the pressure had pushed the bag off the fitting. It dumped 10 or more gallons into the cockpit. Realizing that the left wing was still full I pulled the dump. I flew the task in a bathtub that eventually drained through the 1/2" fuselage drain hole. There was never a handing problem, but my parachute was soaked.

Sean,
I'm not sure whether it was a requirement for certification of the JS-1. I'll try and get an answer.
Gordon Boettger

On Sunday, July 20, 2014 8:31:41 PM UTC-6, wrote:
Yes, it's been done before. There's a great story about the Schweizer 1-35

flight test with one tank full and the other empty. Bernie Carras (who

was the corporate test pilot for a long time) had a hard time getting

the spin to break. It finally recovered fairly low, and he landed the

plane. He gave the plane a few extra kicks once he got out, just for

good measure!



Matt

I doubt if my father ever kicked the prototype 1-35.

The problem was not with spinning the sailplane with water in one wing, that was ok, but when it was in a tail heavy flat spin with a lot of jettisonable lead at the tail that did not jettison as it should have, but finally did.

Mike

Richard Starke, test pilot for the JS1C, is currently working in Mojave, CA and living in Tehachapi.
I only have 40 or 50 hours of JS1B and C, all at 18m so not familiar with circumstances that could lead up to whatever caused the tragic accident in Texas.
It's a fantastic glider to fly. JS1s are flown with a reasonably mid-range CG, so doubtfully pushed aft of the limit.
Jim


On Sunday, July 20, 2014 5:37:23 PM UTC-7, nimbus wrote:
For what it's worth, I have about 5 flights in the 18m JS-1. These flights were conducted in wave and thermals and from my little experience in the JS-1, I was thoroughly impressed with it's handling characteristics, especially at slow speeds. It was extremely easy to fly and even in rotor, handled exceptionally well at slow speeds at various bank angles. There weren't any sneaky things about it throughout all flight regimes.

Personally I think it's totally coincidental that several accidents occurred in the JS-1C within a relatively short time period. I sat through Uys Jonker's talk at the convention and if my memory serves me correctly, he mentioned that during flight testing, the JS-1C was fully loaded with water, then water depleted from one wing, and then the aircraft intentionally spun into the heavy wing with a successful recovery. Pretty impressive. It's a really strong glider.

I'm not making any comparisons to other similar sailplanes. Just my take on the JS-1.



Thanks,

Gordon Boettger

At 04:06 21 July 2014, nimbus wrote:
Sean,
I'm not sure whether it was a requirement for certification of
the JS-1.
I'll try and get an answer.
Gordon Boettger

A couple of the junior guys at the factory told me that they
watched a very asymmetrically loaded spin test that was
required for NZ CAA certification and that their lady
representative was there when Uys flew that test. The story
they told me was that the spin was pretty wild and that she
later told Uys that she was sorry he had to go through that
experience.

The manual says that:

"It *may* be possible to recover the JS1 from a spin with a
significant asymmetric water ballast loading, provided correct
recovery procedures are followed:

1. Apply full rudder opposite to spin rotation
2. Simultaneously release the elevator back pressure by moving
the stick fully forward
3. Close the airbrakes (I guess that assumes landing
configuration. JPG.)
4. Move flaps to full negative position (Position 1)
5. Apply aileron into the turn
6. Centralize the controls when the rotation stops
7. Gently pull out of the resulting dive"

The emphasis on fully forward stick, fully negative flap and into
turn elevator being the differences from standard (including
normal JS1) recovery.

On Sun, 20 Jul 2014 20:53:12 -0700, Sean Fidler wrote:

Does anyone know what failures are possible (or that have happened or
are known) with other manufactures wing water systems?

I remember a clubmate telling me that he had a sticky dump valve on his
ASW-20 which resulted in only one wing emptying when it dumped water.
Said it happened twice and that he didn't notice any problem in the air
either time - just that the full wing thunked down soon after he touched
down at the end of the flight.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Sunday, July 20, 2014 11:53:12 PM UTC-4, Sean Fidler wrote:
That's crazy. Well, here is to those daring test pilots!



That said, I just learned first hand that a modern glider is capable of losing significant wing water in flight. I visited the 2014 Canadian Nationals this summer was shocked to learn that a brand new ASG-29 returned to the airport with a bit of a surprise. The cockpit was half full of water upon landing. The pilot/owner could not be sure what had happened or how. Was it the fuselage tank or the wing, etc? We suggested that he put the wings up on horses and refill it (before attempting to fly again). He did and sure enough one of the wings leaked, alot! The inboard tank seal (a 3x4 panel on the very inboard part of the wing thru which the ballast dump valve control rod runs) somehow failed during the flight.



So, the wing water tank had definitely been draining into the cockpit at some rate during flight. Additional water was likely draining out the gap between the wing and the fuselage as well (depends on the tapes ability to withstand the water I suppose). How much total water that was out of that wing we will never know. It certainly was possible that the leak was large enough for the glider to have lost all of the water in that one wing. Scary, scary stuff.



I sure hope that scenario never happens to me (or anyone else). That said, I feel better knowing the manufactures are testing that scenario for us. Are all manufactures testing for spin recovery with a full and empty wing? I never would have imagined that that condition could be recoverable. I am impressed that the JS1 (or anything else) could pass that test albeit with a test pilot who knows that one wing is indeed empty (and which wing that is)......



Does anyone know what failures are possible (or that have happened or are known) with other manufactures wing water systems?



This is a very interesting side topic actually. No this does not mean that Punchaz comments are back on the table again ;-)!



Thanks in advance.



Common stuff includes not putting in the little drain plugs in the root rib area of some gliders with integrated tanks. Valves and bladders can fail and leak.
One very useful thing to do is leave about 1 inch of the trailing edge not taped.
This lets small amounts of water drain without going into the fuselage and can provide a warning that attention needs to be paid to a problem.
UH

On Monday, July 21, 2014 12:02:25 AM UTC-4, wrote:
On Sunday, July 20, 2014 8:53:12 PM UTC-7, Sean Fidler wrote:



Does anyone know what failures are possible (or that have happened or are known) with other manufactures wing water systems?





My very first contest flight in an LS-3 - at Ionia.



I was climbing in a thermal - as I recall it was right after going through the start gate. I heard they "glug, glug, glug" sound. Looking over my right shoulder I saw a waterfall cascading off the right wing spar. I had failed to burn the wing bag adequately and the pressure had pushed the bag off the fitting. It dumped 10 or more gallons into the cockpit. Realizing that the left wing was still full I pulled the dump. I flew the task in a bathtub that eventually drained through the 1/2" fuselage drain hole. There was never a handing problem, but my parachute was soaked.

FWIW, I think the case can be made that more glider types have had failures resulting in asymmetric loading than have not. For example, my LS8 inner tanks developed an un-intended crossfeed to the outer tanks via a failed vent tube. It showed up for me on takeoff at a ridge site. An under-trained wing runner didn't realize that "I have water" shouldn't translate to having to hold up a wing with 20lbs of force. As soon as he let go - instant groundloop. Luckily, no other gliders or people were staged near the runway.

In this case, there was a Technical Note shortly thereafter to seal up the vent tube permanently.

On Sunday, July 20, 2014 11:53:12 PM UTC-4, Sean Fidler wrote:
...This is a very interesting side topic actually....

For heavens sake Sean! Stick to the topic!
*Houston JS1c crash ONLY (not in any way about a Puchaczs, or anything else!)*