Hatz Biplane Association

I'd like to improve the intercom in my Hatz. It's a basic Sigtronics SPA-400 with VOX, but it requires careful playing with the intercom squelch, I can set it on the ground but I have to adjust it after takeoff and even then it's marginal.

On the noise side, replacing the gel ear pads on my generic DC headset made a big difference. While I was at it I painted the shells brown, which looks a lot better than the pale green headset poking through the brown leather helmet.

My Glasair was like riding in a tin can before I added the interior. Maybe not the wind noise but turning to look out the side opened the mic with hissing and sometime squealing from feedback. I upgraded the intercom to a PS Engineering PM1200 made for high noise levels. I also added leather covers on the mic of my DC headset. Not ideal but tolerable.

I traded in my DC for Zulu ANR. That made a huge difference. I lent them to my wife and she wouldn't give them back. Go figure! I went crazy and bought a Bose A20. I didn't notice a huge difference but I lent them to a friend and he said it was a big mistake as he didn't want to go back to his Zulu's.

In the mean time I upgraded my PS PM1200 and iCOM 210 to a GTR200 with built in intercomm. That didn't make a lot of difference. It was the ANR headsets. I won't go back to passive noise reduction. I did do away with the leather covers for the mic but would put them back on in a windy environment.

My Hatz is noisy, I too have an old passive DC headset, but I never noticed any noticeable buffeting... but there are probably as many kinds of windshields as there are Hatzes. Mine are flat wrap (curved) windshields that are a bit higher than the top of my head, but I'm not a tall guy (5'7").

I just bought a CB-1 and flew it home 10 hours in a day and half. It was pretty miserable but it's not supposed to be a XC plane. I was flying an old mail route, and I couldn't help but think that people used to do this for their job.

Anyway, after getting a shiatsu massage to the head and face for a day and a half, I've decided to explore the idea of placing some micro VGs around the windscreens and maybe the center section. I need to put some tufts around the windscreen and do a little flight testing to see what, if anything can be improved. The idea would be to smooth the airflow, not eliminate it. I didn't find the noise to be too bad, but the buffeting was really annoying. I was wearing an old David Clark Ag helmet and at times the airflow would be trying to lift the helmet from the rear, and the buffeting on the headset was at times painful.

I'm in Phase 1 flight testing and can relay a couple of wind anecdotes. First I used temper foam seat cushions with three layers (soft,medium,hard) that put my head clearly half-way above the Stearman style windshield. I'm 6' and wear a cloth flying helmet. Conditions were very windy to the point of discomfort. I took the bottom seat cushion out and cut approximately 2" of foam off the bottom and reattached the cover. Much better now. My head is just a bit over the top of the windscreen. As I get more proficient with my landings I may remove more of the seat cushion. I have been thinking about some type of mod to attach to the windscreen to reduce turbulence or direct air away from my head. Don't get me wrong the cushion change I made makes it totally tolerable. I too ride motorcycle with and without fairings.

Second, I am using an XCOM transceiver with built in intercom and older non-ANR David Clarks. The problem occurs when I turn my head from side to side checking for traffic and the wind causes the electret microphone to trigger. I purchased a larger mic muff and small leather cover. This helped some but still have the electret triggering when I turn my head. Talking to ATC I must lean forward a bit to get a clear transmission and reception. If I have the radio set to intercom the wind noise is constant and hearing ATC is nearly impossible to hear a transmissions/receptions. So, at least during test flying, I leave the intercom off. If I keep my head in the 'sweet spot' wind does not affect radio use. Anyone with a suggestion to improve communications I'm all ears...lol. Maybe there's a BOSE ANR in my future?

When I ride my bikes in the cold I use a heated jacket liner. It has thin resistive wires snaked around inside that heat up. If your electrical system can handle a 6 or 7 amp current draw something like this might be nice in the plane. It was 40F on my 45 minute ride to work this morning and I was toasty warm. They make heated gloves, socks, and pant liners too, although I've never felt the need for anything but the jacket liner. http://www.warmnsafe.com is where I bought mine, but there are a couple other well regarded companies out there selling similar stuff.

The rear pit is definitely noisier, at least mine is (O-320, long stacks, framed windscreens). There is some downwash off the centersection that you don't have in some biplanes. I use David Clarks with a foam muff covered with a leather cover (AC Spruce) that helps communication a lot, although its still a little iffy at cruise. No trouble with ATC though. I used to fly in the low 30's when my age was in the low 30's. Now the mid 40's are my limit. She sure gets off quick and climbs great in that cold though.
I fly an open pit AgCat sometimes and its actually quieter than the Hatz.

Steve G

Hi Guys,

Mine is loud (open side exit exhaust), windy (short windshields), and no heat, just how it is supposed to be.

Love to fly it in winter (wisconsin), better performance, better weather, and lots of great lakes to explore. We have several folks that plow runways on the lakes up here and then have some fun fly inn/ chili dumps, I am planning to put mine on skis someday. I am good for about 45 minutes when it gets really cold, it is all about attitude. If you ride motorcycles year round you will be fine. Bundle up, get rid of the seat cushion, and if no one will go with you cover the front pit.

Luke

If you like a Cub, you'll love a Hatz.

You're quite the salesman, Mark! Actually, I understand completely - 2 of my motorcycles are antiques without farings and I ride about 15000 miles a year in all weather so I'm pretty tolerant to being cold, wet, and unable to hear.. As far as noise/wind buffeting goes I'll just have to get a ride when I find a good candidate to buy. My wife has insisted on going along on any pre-buy inspection so, obviously, her reaction is more important than mine. I was just so surprised at how serene the PT-19 was that I wondered how the Hatz compared. My wife and I are both pilots and although she loves taking trips IFR in modern aircraft, we find that in the past few years we spend most of our time in our club's Cub. A low, slow biplane seems right in line with our interests.