Doing a 50 hour isn't mensa material and neither is doing an engine change to someone that has an engineers head on them. Crap spelling and grammar in my experence doesn't effect the quality of the job at all. None of the machinery I have worked on be it earth mover, tank, lorry, aircraft, car, pumps, compressors or for that matter washing machines have suffered due to my crap spelling and grammar. Although to be fair some of it has suffered getting beaten into submission with a sodding great hammer or a 6ft lever bar.
And conversely I have a Mensa-level IQ and an Oxford degree, and I can barely change my own tyres and certainly shouldn't be let loose trying to do anything technical to an aircraft...