Skip to comments.Lockheed Martin Potentially Mixed Up Structural Fasteners in Most F-35s
Posted on 02/13/2020 7:01:34 AM PST by Enlightened1
Hundreds of F-35s could have the wrong fasteners in critical areas, according to the Defense Contract Management Agency. But F-35 builder Lockheed Martin says the problem may not need to be fixed.
All aircraft produced prior to discovery of this [problem] have titanium fasteners incorrectly installed in locations where the design calls for Inconel, the F-35 Joint Program Office said in an email in response to a query from Air Force Magazine. Because of this, the engineering safety analysis of the issue has assumed that each critical F-35 joint was assembled with the incorrect fasteners.
Inconel is an alloy of nickel and chromium, and is supposed to be used in places where greater strength and corrosion resistance are required, while the titanium bolts are used in areas where its strength and lightness helps reduce weight. Titanium, however, has a lower shear strength than Inconel.
Both fasteners are called eddie bolts and are similar in appearance except for a number stamped on them. The titanium bolts cost about $5 apiece, while the Inconel parts cost about $20 each. A Lockheed spokeswoman said the two parts are very difficult to distinguish, visually.
The Lockheed spokesman said an initial analysis concluded that titanium has sufficient strength in locations that called for Inconel eddie bolts. Another Lockheed official said components are built with twice the strength specified, but he did not specify whether this was the case with the titanium eddie bolts.
The JPO said analysis as of Jan. 9 concluded that no aircraft operating restrictions or inspections are necessary at this time. It added that the JPO will release a fleet guidance report at the conclusion of the Root Cause and Corrective Action (RCCA) analysis, now being performed by Lockheed. The DCMA said
(Excerpt) Read more at airforcemag.com ...
Careful! Mixing up fastners IS a big deal.
Taxpayers want what we paid a fortune to get.
Must give the pilots a lot of confidence.
At four times the cost.
Typical... although if there was to be a mistake, better it be stronger fasteners were used rather than weaker.
Both fasteners are called eddie bolts and are similar in appearance except for a number stamped on them.
Obviously, it would take an enormous amount of resources to make them look different /s
And how much have taxpayers paid Lockheed for this model?
“A Lockheed spokeswoman said the two parts are very difficult to distinguish, visually.”
And apparently no one thought to put a little paint on one so they could tell the difference
Both fasteners are called eddie bolts and are similar in appearance except for a number stamped on them. The titanium bolts cost about $5 apiece, while the Inconel parts cost about $20 each.
That’s the cost to LM. What did LM charge the taxpayer?
Duct tape can fix this right up.
The Lockheed spokesman said an initial analysis concluded that titanium has sufficient strength in locations that called for Inconel eddie bolts.
Tell me then, Mr Lockheed, why did YOUR design call for a heavier and more expensive bolt?
One thing I've found rather odd in life is the frequency of "mistakes" that work to the benefit of the party making them.
Dont worry, it will only cost a couple billions to fix.
Probably because the bolts are intended for areas exposed to high temperatures and corrosive gases, as the article indicates...
Amen. It’s highly likely the stronger fasteners are needed at critical failure areas such as wing joints. LM should be made to pay for this inexcusable foul up and make inspections & take corrective action on the entire fleet ASAP.
$15 per bolt profit explains why they both have the same name and extremely similar appearance.
There are many different grades of Inconel and Titanium alloys.
Considering the application they most likely spec’d Grade 5 Titanium and Inconel 725.
The properties wrt the various strengths are very similar with one exception being the category of Ultimate Strength where the Inconel has a 20% advantage.
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