<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
         <<  Lancair Builders' Mail List  >>
         <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>

From: David Jones

I flew yesterday  with my new AIM carbon monoxide meter, and got a big surprise--It showed  41 ppm of CO in the cabin of my IV.

Interestingly, I always fly with an oxygen cannula on and running, because I feel that it makes me a more attentive pilot.  This has probably saved my life.

I have several factors at work here that may be causing my high CO level--They are a domino effect of the crappy heater engineering that I have continually complained about.....

In the IV,  the cabin heat is bled off the turbo intercoolers by a sonic tube welded on the ass end of the intercooler.  If I am flying at low speed--less than 31 inches MP, the cabin pressure exceeds the bleed pressure, and I have no heat coming into the cabin.  None.  Zippo.  Ice Cube time.  If I raise the MP to 32 inches, I begin to get heat.

To somewhat compensated for this, I have a slide valve installed in the duct supplying cabin air from the NACA inlet in the tail.  With no heat in the cabin, I shut the air supply off, otherwise the temp in the cabin is unbearable.  When that valve is open in the summer time, the air flow is tremendous, by the way.

In any event,  yesterday my cabin air change was quite low, and I got a 41 ppm  reading on my CO.

Tomorrow,  I will open the slider on the vent and see what reading I get.  If it decreases,  you will start to see me writing about fixing the heater so it works.

Am I the only person flying a IV with a non--functioning heater?

PS---thanks for the suggestion of buying the AIM detector--It may have saved my life.

David Jones, Pecatonica, Illinois

LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.