>>>> Steve, why do you want the dead engine to windmill ? Didn't the CAFE folks find that a =stopped= prop was better for glide range than one wind milling?
Hi Art - thanks for the input. You are addressing the topic of what's best after the engine quits and I think you are right, a wind milling propeller creates more drag. I am concerned about the things that make the engine go quiet in the first place. There are various causes of a temporary fuel supply interruption and we are inventing new ones all the time. Some (not many) are genuinely not our fault, most are - we are only human. The ultimate sin is forgetting to change tanks - but it happens. It happened to me in a bird just like yours, the day before I got to solo. My instructor was fascinated by some whales in Blue Water Bay (George coast, South Africa) and made me circle at 500'. As you know, the AA1 uses the tubular spars as fuel tanks and we were probably using the inside (low side) tank. This was 1976 so I don't remember if we ran the tank dry or the turn was just badly coordinated - but I do remember the sudden silence at 500', 400' 300' ..... It was a lesson in emergency procedures to see my instructor react - like lightening he changed tanks and flipped the fuel pump switch - 200'; 100' and the silence was gone. If the motor had not been wind-milling and patiently waiting for the fuel to arrive - we would have really surprised the whales that day. I can tell another one about the same idiot after going solo, getting his ticket and clocking up a few hundred hours, but I think you see why I prefer to live with the over priced, inefficient and technically outdated airplane engine. It keeps turning, NO OTHER REASON. On that topic - look into ice warning gizmo's for the carby. I have seen a few really good low cost units on the web (not for certified birds). Important not to be caught napping, particularly with a motor that does not wind-mill - the motor must still be rotating if we hope to suck in some warm air and melt the offending ice - yanking the carb heat after the motor stops turning will achieve nothing. Two lessons learnt about carb ice: = when initially applied, the motor may get really unhappy while it is drinking melted ice for a few seconds - don't think you have done something wrong and shut off the carb heat, stay with it. = Icing generally starts close to where the butterfly is. If you feel any resistance or roughness in the action of the throttle control, hit the carb ice. = If the go lever is already frozen solid, don't panic (yet). If you can live with the power setting while the ice melts - OK. Maybe you pulled it right back in a rush descent and it froze there - why would I know all about that? The weather circumstances that promote getting down fast may also be the conditions that promote icing (and keep you busy enough to forget to pull the knob). If this happens, rap the control with the palm of your hand (friction nut off) with increasingly more force. Get onto it fast and the ice will probably be light (weak) enough for the butterfly to break loose when you rap it just right. Again, the motor will get really unhappy with a mouth full broken ice - stay with it. If it stops wind-milling, hit the starter and start looking for a place to set down. Don't worry about rapping it hard enough to break something if a forced landing is on the cards anyway. Think about this when designing and fitting the engine controls, fortunately Piper did and I am here to talk about it. Have a great week Steve J
