Boeing main wing spar
 

Hi all

​​​​Im having a discussion with someone about boeing airliner wing construction. He is asserting that the main wing spars are made from titanium but this does not seem right to me. My understanding that it is aluminium/magnesium alloy. Specifically 70s, 80s and 90s construction on the 747,767 and 777. Can anyone help confirm this?
thanks for your help.

According to this its Ally.

https://www.airframer.com/aircraft_d...nd%20aluminium.

I've never heard of titanium being used in the primary wing structure - it's all a high-tech aluminum alloy (at least prior to the 787 - which of course is composite).
Ti gets used in other places, but not the primary wing structure.

The only large Titanium part in the wing structure of a 747 is the wing landing gear support beam which supports the aft trunnion of the wing gear. Possibly this is also Ti on other Boeing models.

727 is aluminium alloy. The rear spar lower web at the root of one I had to remove the paint and the tonnes of filler the French MRO that previously had the flying palace had used to cover the corrosion (and the crack that had grown to14 inches) was defo 2024 alloy.

The Lockheed A-12 and SR-71 were mostly made of titanium for heat resistance. It would be quite likely that the spars were made of titanium too. They even founded some innocent looking front company in Canada to import all the titanium needed from the USSR.

https://qph.cf2.quoracdn.net/main-qi...8f6b0f4149f806Lockheed Martin

The OP asked about Boeings.

And Titanium spars.