This picture was inspired by a truly brilliant fill over on the Cabin Pressure Fic Meme. You can find it here: [link]
So - Martin fixing Gertie in his old flight suit, which, due to popular opinion, has a patch on his knee and is worn (on hot days) with the torso rolled down and the sleeves knotted around his waist.
Suffice it to say, temptation was too hard to ignore
Anyway - I hope you guys find it amusing either way