Chad Irby wrote:
Scott Ferrin wrote:
"Tarver Engineering" wrote:
"Mike Marron" wrote:

I don't know how much an F-4 ECM pod weighs, but I do know that it
would require a hellacious amount of G's to cause the bolts that
fasten the pod to the airframe to fail.

How could you possibly know that?

Math.

...and a near-religious faith that new bolts are just as strong as old
bolts, while corrosion never happens and flightline troops never make
mistakes.

Why y'all respond to the dreaded "tarv troll" is beyond me!
In any event, Chad, you're absolutely correct that flightline troops
make mistakes. But the good folks in St. Louis at the McDonnell
Douglas plant have a few scruples to speak of and you can rest
assurred that they designed the F-4's ECM pod with hamfisted
pilots and/or hairy-assed line mechanics in mind.

With regards to your comments about threaded areas and/or
corrosion possibly weakening the ECM attachment points, as
you know AN hardware comes in a wide variety of different flavors
and anything prone to corrosion is generally cadmium plated.
And AN bolts have "rolled" threads (as opposed to "cut" threads)
which results in a strengthening of the bolt in the thread area.

But once again, doubtful the "brainy" types in St. Louis designed the
ECM pod fasteners to take shear loads in the threaded area
anyway (it is a bad practice to do this with any bolt, AN or
otherwise). From a practical standpoint even if you took took an
AN bolt and clamped it in a vice then punished it with a sledgehammer,
you'd find that you could exceed the yield strength without actually
breaking the bolt as it would stretch or bend quite a bit before
snapping.

The bottom line is that, yeah, I actually DO have a "near-religious
faith" in AN hardware since it's my own butt hanging from one single
solitary AN6-44 bolt when flying my own personal homebuilt aircraft
that's rated to +6, -3 G's. I don't simply wrench on A/C and sign 'em
over to some guinea pig to test fly, I actually fly A/C that I worked
on, modified, or constructed myself. I'm not claiming to have flown
an F-4, but that's how I know that it would require a hellacious
amount of G's to cause the bolts that fasten the ECM pod to the
F-4's airframe to fail.

Film at 11.

Cool. I assume it's a film showing an F-4 ECM pod departing the
airframe in Vietnam as you said?


-Mike Marron
A&P, CFII, UFI (fixed-wing, weightshift, land & sea)