Hawk Troubleshooting

[Jeff Eggers]

I’m flying an ASW-24B with an LX9000/V8 configuration, which has Hawk enabled.

I’ve never been successful in getting Hawk configured to the point I feel it is useful and working, so I’m looking for someone with familiarity on how to set it up and use it effectively.  If anyone is willing to consult with me on how to try some things, I’d be grateful.  I’ve consulted with LXNAV and done AHRS alignments, firmware updates, plumbing leak checks, etc.  

And FWIW, here is my current Hawk profile and plumbing configurations:

·      Setup>Vario Parameters>Hawk Enabled = Yes

·      Setup>Vario Parameters>Hawk Wind Variance Settings = .07, 30, 10

·      Setup>Sounds>Audio>Vario Audio Source = Hawk

·      Setup>Sounds>Audio>SC Audio Source = Hawk

·      Graphics>Glider and Track>Path Style = Hawk Netto

·      Graphics>Thermal Mode>Enabled=Yes

·      Graphics>Thermal Mode>Color Circles By=Hawk Netto

·      Hardware>Vario>Vario Needle=Vario

·      Hardware>Vario>SC Needle=Netto

·      Hardware>Vario>Needles=Vario&Hawk

·      Hardware>V80>TE Compensation = 100% (Electronic)

·      V8 TE and static ports are t-connected to Probe Static Pressure

·      V8 pitot port is t-connected with airspeed to Probe Pitot Pressure 

Thanks, 

Jeff

[Jeff Stetson]

Jeff,

I went through considerable experimentation with the X-100/HAWK setup installed in my Ximango 1 1/2 years ago. Though I will continue to fiddle, it's working quite well for me now, IMO. I'll share some observations as a personal experience, not as a resident expert on the device and some may only apply to my very-mediocre performing motor glider.

1) Try hooking up and referencing to the usual total energy probe. Using the electronic compensation, I was never able to convince myself it was working correctly or how to set the percentage of compensation. Comparing with my good old B-40, the vario response of the S100 on TEK was identical; with electronic, it was not. 

2) Presumably the goal of the leveling procedure is to establish a "zero" for in flight use. The install procedure is to use the weight & balance level as an equivalent. With my ship, I found this not to be the same. While on the ground in the W&B reference position, I closed and latched the canopy, picked a nice spot repeatable spot on the frame that I could also see from the inside, and took a reading with an electronic level. (A phone app isn't stable enough, and the cheap rattly ones don't work in turbulence. The 

Klein Tools 935AG worked well.) In the W&B level, this gave me 2 degrees nose down measured on my canopy rail reference. Previous flight testing showed me at a minimum of - 3 degrees, ranging to -5 degrees at best L/D. I zeroed HAWK for -3.5 degrees, about equivalent to min sink speed. (I think zeroing at a faster speed equivalent might work better - but it's a massive (literally) project to set up a big heavy ship for that again).

3) My ship is 21 years old (yours, older). Even making the big assumption that the advertised polar while new was correct, it's unlikely to be as good now, unless the wings have been re-profiled, etc, etc. If HAWK thinks that your performance is better than it can be, it's going to exaggerate. With a rare bird, it's hard to find accurate data, but I guessed at a crappier polar, entered that, and went through a whole process of measurement (a rather clever one, actually) to confirm. (Remember, polar goes with TAS, not IAS!). You might try knocking your reference polar down by a significant amount for starters. HAWK seemed to exaggerate less after I redid mine. The sink rate in the range of thermally speeds is at least 20% worse ... sadly.

4) HAWK assumes perfect flight technique, which I'm lacking. Likely tooBut still, it's smooth math and doesn't consider necessary imperfections like having to hold opposite aileron to prevent overbanking or a slight inward slip most of us do to minimize that. It will thus always be somewhat optimistic, and more noticeably so in weak conditions. But I do find it super useful in flight, preventing turning in to foolers and the associated painful altitude loss.

DM me if you wish to phone chat.

-J  

[Greg Arnold]

Anyone know if the Stefly Larus with Dual GPS is any easier to set up than the Hawk?

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[Richard Pfiffner]

Check that you have no leaks in the Pitot.  I had one where a there was a pitot leak and it made things unusable.

.07 to .11,  30, 10

Richard

www.craggyaero.com