I was surfing the net the other day and found the Radial Rocket, what a cool plane. I was looking over the engine, a M14P and noticed that it used an air starter. What a good idea I thought. I have seen these used on very large diesel engines but not in an application such as this.
I think that originally the planes that these engines were installed in did not have an electrical system therefore the air starter. With modern planes relying more and more on electrical components it puts a large strain on the battery and electrical system. By taking the starter load off of the battery one could use true deep cycle batteries and have longer battery life and should the charging system fail in flight then deep cycle batteries can supply the buss load for a longer period than a standard battery that has to supply the start motor load.
True deep cycle batteries are available in the same case sizes as the current batteries. I have four similar sized batteries on my electric bike ( 12 VDC 20 Amp-hour x 4 = 48 VDC 20 Amp-hour) and they have been very dependable while going through many charge/discharge cycles.
Could an air start system be used on the Lycoming engines in the RV? Or could one be made? I would think that weight would be a wash one way or the other. The air receiver and valves would be about the same weight as the starter motor it replaces. If Li-Ion batteries are available they should weigh a little less than their Lead-Acid versions and have greater capacity.
Bob Parry
I think that originally the planes that these engines were installed in did not have an electrical system therefore the air starter. With modern planes relying more and more on electrical components it puts a large strain on the battery and electrical system. By taking the starter load off of the battery one could use true deep cycle batteries and have longer battery life and should the charging system fail in flight then deep cycle batteries can supply the buss load for a longer period than a standard battery that has to supply the start motor load.
True deep cycle batteries are available in the same case sizes as the current batteries. I have four similar sized batteries on my electric bike ( 12 VDC 20 Amp-hour x 4 = 48 VDC 20 Amp-hour) and they have been very dependable while going through many charge/discharge cycles.
Could an air start system be used on the Lycoming engines in the RV? Or could one be made? I would think that weight would be a wash one way or the other. The air receiver and valves would be about the same weight as the starter motor it replaces. If Li-Ion batteries are available they should weigh a little less than their Lead-Acid versions and have greater capacity.
Bob Parry