ORIGINAL: vertical grimmace
ORIGINAL: KentuckyColonel
The do, indeed exist! [link=http://www.youtube.com/watch?v=_jxr4XAWaQA]Here are mine[/link]. Expensive, but worth the money.
They have units that will fit in 1\5th scale warbirds? The only units that I have seen are for 60-90 size aircraft (that seem to only be partially available!)
they have the actuators that are compatable with larger retracts sizes, so you can retrofit the gear to electric they replace the air piston.
http://www.lado-tech.net/products.php?cat=7