"Smartace11" wrote in message
...
"SteveM8597" wrote in message
...
I thought the "AV" in AV-1 was for "air vehicle". I know there was
one that wasn't intended to go into service but did in the end. The
only one I know of that didn't was the "iron bird" that had different
landing gear, wasn't flyable, but was the same size and configuaration
as the production B-2. Could that be the one you are thinking of as
Northrop's aircraft

The Iron bird was just that, a mockup of steel girders with much of the
flight
and mission hardware installed, and the whole thing was tied to a full
motion
simulator. Pretty awesome to see but not eactaly an airplane by any
stretch.
.There wre two static test articles built IIRC tail #s 1001 and 1002,
or maybe
2001/2. One is still at Plant 42 at Palmdale. the other at the AF
Museum.

A simple shake of AV-1 was all that was required to validate the test rig
results.

Iam curious where you got your information. The iron bird "test rig" was
at
Pico Rivera and was officially called the SIL or systems integration lab.
Now
used for structural testing at all.

I was commenting on the Nyquist shake of the B-2, are you confused?

1001. 1002 and AV-1 were stored at Palmdale 60 miles away. 1001 was
loaded up
in a hangar at Palmdale and then shook until it broke at 207% of mission
loading. You can go to the AF Museum today and see the scab plates on the
right wing where it brokeso it could be put on display.

Right, no B-2 was broken to prove the structure.

AV-1 was never subjected to stress testing. It was the first flying
prototype. It was rolled out in 1987 and used to validate initial flying
qualities. It is easy to spot in pictures because it was grey with black
leading edges before the refurb, not black all over as is the operational
fleet.

Do you understand the difference between a Nyquist shake and stress testing?
I expect not, but such a shake produces a nice mathematical model of the
airframe. Using those methods, the breaking point is completely
predictable.