747 problems over Holland yesterday https://edition.cnn.com/2021/02/21/europe/cargo-plane-debris-meerssen-netherlands-trnd/index.html
Also best to fire them at the target 'arse first', thus minimising the incremental damage a hard 'beak first' entry might cause.
According to Karen on mums net, R-R led the way with this technology and was the first OEM to introduce wide chord fan blades into large commercial area engines, back in the 1980's. Apparently three sheet of diffusion bonded titanium, then super-plastically deformed in a vacuum results in a hollow blade with a wide chord, an internal vacuum, and internal warren girder structure for additional strength. Made in that there Lancashire! Things have now moved on with composite wide chord fan blades now common. Mr bimble.
Here’s the comms of the pilots for this very flight....you can’t hear the screams in the background....
Surprised there is so much tech info from Karen on mumsnet, but apparently the blades with holes in them are turbine blades which sit behind the combustion chamber. As some of them operate in an environment above their material melting point, whilst experiencing significant cf loads due to them rotating at up to 15,000 rpm, they utilise film cooling where cooler air bled from the compressor is fed through the blade root up through internal cooling passageways in the blade and then out through small holes in the aerofoil to provide a film of cool air around the aerofoil which stops it melting (which is one of the reasons you avoid volcanic ash clouds as the volcanic dust can melt and turn into glass and block said holes). Spark eroding these holes stopped some time ago and they are now formed as part of the lost wax casting process, or are laser drilled. Also, despite their complicated shape, carefully controlled cooling of the turbine blade castings during manufacture results in the blade being formed as a single crystal, with no internal grain boundaries, which would weaken the structure. Proper boffinry right there!
