But what realy is different structurally from her sister,s?I have heard stories of surviving incredible high sink rate landings
Back when Flaps 40 was used to landing, one could very easily get into a very high sink rate with little effort if you were not paying attention. With Flaps 30 you still could get into a pretty good sink rate, but you really had to work at it by not paying any attention to what you and the aircraft were doing.
As far as I know all 727s have the Flaps 40 position blocked now, you can only have a maximum of 30 degrees of flaps. There were three primary reasons for the maximum of 30 degrees of flaps;
1. Fuel burn on landing with flaps 40. It takes a lot of power to keep a 727 on the glide slope at Flaps 40.
2. The very high sink rate that could happen with 40 degrees of flaps.
3. Noise abatement on approach and landing. See number 1, more power, more noise.
Because of our unique operational requirements, we were allowed to remove the block and use Flaps 40 when it was required.
Oh, when you do land with Flaps 40, when you pull the power off you drop straight down, so you want to be real close over the runway when you do, like less than a foot or two. Trust me on this.
