Lovely Lady Bumps?

I believe this starts to occur over a long period of time and can be also caused by constantly (i.e several times/sectors a day) being pressurised and then de-pressurised when climbing and descending.

I suspected they were stress marks of some kind….i have seen some similar shots of various aircraft on Airliners with this – the most notable was a B52 that looked like it had flown through a horizontal hailstorm with footballs!! 🙂

I was once told by a Britannia engineer that It’s to do with the forces on the wing during flight forcing the wing backwards, If you stood at the nose of a BY 737-200, and looked aft, down the fuselage, the efffect of the light made it look far worse than it actually was.

Not sure of the technical name, but they are stress points.

As a plane lands, the fuselage bends down a bit. Hardly noticable, but it bends the skin. The skin can not bend outwards because it is curved inwards. So it has to bend inwards. Also, the fuselage bends downwards, so the skin bends upwards: action-reaction etc.

These dents are formed in the holes of the frame that holds the airplane skin. You can find this on almost all planes.

This can be found mostly on narrowbodies, and then in particular long ones. Simple reason is that there is more to strech. Try bending a pencil of 3 cm and a pencil of 30 cm. The 30 cm pencil will bend more. A narrowbody has less strength then a widebody, thus making it more prone to the dents. Compare it to bending a 30 cm twig with a diameter of 3 cm, or a 30 cm twig with a diameter of 10 cm.

beats me? of course iam easily beaten, but it is strange…..