Factory Construction Numbers VS Bureau Numbers

[N3Njeff]

Hey to all you Mental giants I got a question for you!!!

Is it my understanding that Navy Bureau numbers were only issued when the aircraft was ready for delivery??? When orders were given, lot numbers were issued to those aircraft???? Reason why I asked this is one of our members is restoring a VERY orig. N3N. When I went to go see it, he pointed out a small tag riveted on the firewall with 3 numbers stamped on it. When he was up in ohio he had asked about the tag with another member and he too did not know but DID find this tag on a couple of his firewalls.

I am trying to figure this out but with current flying aircraft, that tag has been removed due to a early AD where the firewall is to be replaced with stainless.

While on my quick trip to VT, I went out into the bushes and took a look at our other airframe and it DOES have that tag. Anyone think that this might be a Factory Construction Number like I do???

[snj-5]

Just a thought / guess, but that could be a 3 digit construction / line
number... These airplanes were built in batches on contracts (500
aircraft at a time for example) and there would likely have been
a way to identify each "line" number on the factory floor assembly
line for a given contract / batch of aircraft (we still do this today in
the Commercial / Aerospace world).

FWIW, I've observed what are probably these "line numbers"
scribbled onto various components / assemblies on my SNJ-5
project.

Bela P. Havasreti

[t28pilot]

US NAVY Bureau numbers were issued when a contract was approved by the govt for a certain type and qty of airplanes. They were not yet assigned to an airframe. It did happen where earlier Bureau numbers would have been placed on airplanes manufactured AFTER a later number. Reason, a particular contract might specify a certain modification, if a delay in avionics, structure or whatever caused a slip in delivery then Buno 12345 could have been in service and manufactured before Buno 12300 since it was a different lot or contract number. With that being said, construction numbers from a manufacture were usually consecutive in producton.

[N3Njeff]

Thanks,

This number was also found marked in pencil in another location.