they would then slide the tail assembly back on , and after a second independent grubber had double checked the engine and flying control connections , a cross trained mechanic/tractor driver would tow it outside , under the supervision of any supervisor ( not just a specialist aircraft handler that had been sitting around waiting ) and the grubber supervisor ( or even the plane captain if hed had the extra training ) would then ground run the new engine to check it out ( but not when i am asleep - thank you very much ) .