Points for Pilots

Most small airplanes use a heat muff around the muffler for heat in the cockpit. Fresh air is piped into the heat muff. The heated air is ducted into the cockpit as needed. This system works well, provided exhaust gases do not become part of the heated air. If that happens, carbon monoxide (CO) enters the cockpit. Even small concentrations of that deadly gas can incapacitate pilots and passengers. Thus, great care must be taken to prevent this disaster. There are other ways CO may enter the cockpit: for example, due to a flawed design of the exhaust system where in a certain attitude CO may enter a fresh-air intake. We had this problem originally in our plane during steep angles of attack. A redesign of the exhaust system solved the problem. The publication Detection and Prevention of Carbon Monoxide Exposure in General Aviation Aircraft by the Federal Aviation Administration has an in-depth discussion of the CO hazard. Here, we shall not repeat that material, but summarize some...

We have had seven major causes for rough running of our Rotax 912 engine.  Four of them are covered in this post. They are: fouled plugs, faulty ignition cable, improper grounding of ignition module, and broken exhaust baffle. The remaining three causes are discussed in separate posts:  carburetors not synchronized ,  imprecise propeller pitch , and  worn Belleville washers in the gearbox . Fouled Plugs During most years, we fly almost exclusively using 100 octane low-lead avgas (100LL). Our use of 100LL avgas is not a choice but forced on us: Almost all airports that used to offer automotive gasoline (autogas) have stopped that service.   The term low-lead  for 100LL is an industry ploy to make us feel good. One gallon of fuel contains about 2 grams of lead. That is a large amount compared with the quantity in the leaded automotive gasolines of the 1960s.  The lead problem stems from the fact that in recent decades Continental and Lycoming, t...