Insult on insult!!!

[judow]

I don't know for sure...but they're buying FIATs again after the last fiatsco.

Good one. Comment, NOT car.

 

[Deleted member 8987]

And yet....I recall a Canadian TSB or some such on loss of a helicopter gearbox oil pressure....due primarily, if I recall, to titanium gearbox studs snapping......

 

[DrEntropy]

It can be brittle. Wish I had kept some of the photomicrography of the various materials. Did a stint in a metallurgical lab as the photographer for a while. I have a couple Charpy and tensile test pieces of different metals. Neat stuff!

BTW: If you take a grinder to it, it sparks brilliant WHITE. Steels of various grades can be separated with a "spark test"... hit it with a grinding wheel and "read" the way the sparks look. Color, pattern, the way the "branches" occur.

 

[Guest]

And yet....I recall a Canadian TSB or some such on loss of a helicopter gearbox oil pressure....due primarily, if I recall, to titanium gearbox studs snapping......

Fat chance of that in my case. Couldn't chase her away with a stick..she'd come a'runnin' if I ran too. :laugh:

 

[Deleted member 8987]

https://en.wikipedia.org/wiki/Cougar_Helicopters_Flight_91

warning....above link can be somewhat graphic

TSB identified a broken titanium stud as part of the gearbox oil filter assembly. Sikorsky had previously recommended that the titanium stud be replaced with a steel stud within one year or 1,250 flight hours of a 28 January 2009 Alert Service Bulletin, following a total loss of oil and emergency landing in Australia in August 2008.[22] On 21 March Les Dorr, a spokesman for the FAA, indicated that it would release an Airworthiness Directive calling for the replacement of the studs on other S-92A aircraft, most likely on Monday 23 March, but that the Directive would apply only to US-registered helicopters.[23] The FAA had issued previous Airworthiness Directives AD 2005-12-03, AD 2006-11-14, and AD 2006-15-19 for problems with the main gearbox of that type.[1] The FAA had also issued Special Airworthiness Information Bulletin (SAIB) number SW-09-19 Sikorsky S92A Main Gearbox Emergency Procedures dated 19 March 2009. The SAIB indicated that a recent procedural change, Sikorsky Safety Advisory (SSA) SSA-S92-08-006, dated 26 September 2008 may not have been appropriate and that it had not been approved. The European Aviation Safety Agency had already acted to highlight this problem.

Late on 23 March Sikorsky issued a news release indicating that it had furnished replacement studs and tools to all operators and that 50 of 91 aircraft had been reworked already.[24] The FAA later grounded flights until the parts had been replaced,[25] issuing Emergency Airworthiness Directive 2009-07-53 dated 23 March that required the replacement of the studs before further flight.

 

[Guest]

Th' stuff's retention properties are incredible too. I have a wedding ring made of it.

And yet....I recall a Canadian TSB or some such on loss of a helicopter gearbox oil pressure....due primarily, if I recall, to titanium gearbox studs snapping......

Fat chance of that in my case. Couldn't chase her away with a stick..she'd come a'runnin' if I ran away too. :laugh:

https://en.wikipedia.org/wiki/Cougar_Helicopters_Flight_91

warning....above link can be somewhat graphic

TSB identified a broken titanium stud as part of the gearbox oil filter assembly. Sikorsky had previously recommended that the titanium stud be replaced with a steel stud within one year

...and her mother prob'ly reccommended I be replaced by ANY stud... :laugh:

Sikorsky don't know nuthin' 'bout divorsky!

 

[Guest]

Terrible to heat about those guys.

That's one reason why I don't trust any aircraft with the glide ratio of a brick.

 

[PC]

It can be brittle. ....

As can steel or aluminum or most any metal. It depends on the alloy and the heat treatment.

And yet....I recall a Canadian TSB or some such on loss of a helicopter gearbox oil pressure....due primarily, if I recall, to titanium gearbox studs snapping......

Titanium is great stuff. But it's weaker than steel. Replace a steel fastener with a the same piece in titanium and it won't withstand the same stresses.

What makes titanium desirable isn't its strength, but its strength to weight ratio, allowing parts that are both strong and light (if appropriately designed).

Sadly, those studs were apparently underdesigned.

 

[Deleted member 8987]

Apparently.

 

[Guest]

Apparently.

:lol: