Boeing faces fresh questions about the safety of its aircraft after an engine fire on a transatlantic flight from Edinburgh caused an emergency landing soon after takeoff.
Flames were seen by passengers briefly shooting from the engine of a Delta Air Lines 767 soon after it took off for New York in February last year, after a turbine blade broke off during takeoff.
The flames subsided while the plane was airborne but it made an emergency landing at Prestwick airport south of Glasgow, where ground crew noticed fuel leaking from the plane’s right wing.
The Air Accidents Investigation Branch, the UK government agency that investigates aviation safety, has written to the Federal Aviation Administration in the US asking it to take action with Boeing, which has its headquarters in Virginia.
Are you implying they are not metal? Or that their heat treatment makes them brittle? If it’s the latter, that’s clearly a defect. Metals can achieve high rigidity and still retain great resistance through heat treatment.
Metals are crystalline, and high stress loads associated with being rotated like crazy make things brittle. IDK how brittle though, steel normally is super stretchy if I remember my studies right.
That’s why I asked for clarification. The line about them being crystalline makes no sense. Copper is crystalline, and can be super malleable or quite brittle depending on the grain structure. And you just don’t use brittle materials for high speed rotating equipment. And there are non destructive tests to check for embrittlement/fatigue.
Metals are made of crystals, they usually defourm along the grain boundaries and fatigue cracks also grow along them. By eliminating those boundaries you reduce the chance for fatigue cracks and make the overall blade stronger.
Of the top of my head, IIRC the blades in a turbine are grown into a single crystal of titanium so there’s no weak points between the crystalline structure.
Edit. https://www.theengineer.co.uk/content/in-depth/jewel-in-the-crown-rolls-royce-s-single-crystal-turbine-blade-casting-foundry
Not titanium, nickel alloy.
Christ on a cracker!