Brief Description: Alternate Air Door Installation - Part 1
In certain weather conditions, ice can form over the main throttle body intake. If enough ices builds up, the air to the engine can be restricted and result in a reduction of power. Eventually ice can completely cover the intake and the engine will quit running completely. Obviously, this isn't exactly a desired outcome of flying in less-than-idea weather. For this reason, an "Alternate Air" input is added to the snorkel intake system. This allows the pilot to pull a control in the cockpit and open a small door in the side of the snorkel allowing warm air - or just any kind of air for that matter - into the engine's intake. This will bypass the obstructed normal intake and allow the engine to continue running.
The installation of the Alternate Air door was pretty straight forward and came out very nice. The control from the cockpit works nicely and is very positive. I added a small collar to the linkage that can be see about two inches back from where it connects to the door. This keeps the control from pulling the door too far open and jamming. Notice also that there is a small flange at the top of the door frame that keeps the door from going too far closed as well as holds it tightly against the frame when the door is closed Pretty slick setup, really. By the way, that collar is from my radio control airplane building days some 30 plus years ago! I still had it laying around it a box of "goodies".
