Actually Boeish is a language which should be discouraged.
Technical occupations like commercial aviation involve a lot of jargon. Jargon is words which have special contextual meaning even though they may be otherwise quite ordinary words.
If some one asks whether you have a back-up for your Powerpoint presentation, you will assume they mean an electronic copy of the source rather than a pile of supporting affidavits or a group of large mean looking black blokes with polished heads.
If Boeing start talking about non-normal rather that abnormal then you flush away all the meaning of abnormal and have to waste time trying to gauge whether Boeing are trying to create some new subtle meaning for their new jargon word. You may be left thinking "do I use this procedure when things are only slightly unusual but not when things are really bad- in which case what am I supposed to do then?"
In the UK you can see some stuff specially written to be plain and simple (I think Egg is like this). It is so much better.
I think Boeing are just being self-indulgent allowing their people to write waffle when a tiny bit more thought could give us the meaning phrased accurately, simply and unamibiguously.
These people are simply being lazy. They don't quite like the connotations of an existing usage so they make up a new one. Trouble is as that point they are the only ones who understand what the new usage means. Everyone else now has the burden of working it out.