Can F-15s making 9G turns with payload?

Chad Irby wrote:
Mike Marron wrote:

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).

You can "doubt" all you want, but that's not how the damned things were
put together.

But according to you, that's how the damned things came apart. Yea or
nay?

-Mike Marron

Mike Marron wrote:

Chad Irby wrote:

You can "doubt" all you want, but that's not how the damned things were
put together.

But according to you, that's how the damned things came apart. Yea or
nay?

What I'm saying is that the Missile Well Adapter for electronic warfare
pods for the F-4 Phantom was held onto the plane by four bolts running
straight up into the airframe.

You claimed that was "doubtful."

You were (and are still) 100% wrong.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

Chad Irby wrote:
Mike Marron wrote:

But according to you, that's how the damned things came apart. Yea or
nay?

What I'm saying is that the Missile Well Adapter for electronic warfare
pods for the F-4 Phantom was held onto the plane by four bolts running
straight up into the airframe.

You claimed that was "doubtful."

You were (and are still) 100% wrong.

Oops! Instead of answering the question now you're dodging the
question and putting words in my mouth.

I doubted that A) the ECM pod ripped apart from the airframe as you
said, and B) the pod fasteners were designed to take shear loads in
the threaded area.

I did not "doubt" what you said about them "four bolts running
straight up into the airframe."

Now, pardon me if I missed something but I respectfully ask you
once again (for my own edification) in your opinion -- was it the
bolts, the design itself or what was the culprit with regards to what
you said about the ECM gear "ripping apart" from the airframe?

Sincerely,
-Mike Marron

On Sat, 20 Sep 2003 20:10:07 GMT, Chad Irby
wrote:

In article ,
Mike Marron wrote:

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).

You can "doubt" all you want, but that's not how the damned things were
put together.

Thinking about bolts shearing I wonder if it could have been like
pylon sway brace bolts that would get worn. No visible damage to the
threads, but when you went to torque them down they wouldn't be tight
against the pod. With a pod because of the length you could shake them
and get a feel for a loose sway brace bolt. Maybe 3 bolts torqued up
tight to the plate and one a hair away from the plate would decrease
the load carrying ability enough to have a pod come off?

Wasn't something said about mechanics carrying bolts around?
I remember now we use to carry spare sway brace bolts and nuts in our
truck.

Buzzer wrote:

Thinking about bolts shearing I wonder if it could have been like
pylon sway brace bolts that would get worn. No visible damage to the
threads, but when you went to torque them down they wouldn't be tight
against the pod. With a pod because of the length you could shake them
and get a feel for a loose sway brace bolt. Maybe 3 bolts torqued up
tight to the plate and one a hair away from the plate would decrease
the load carrying ability enough to have a pod come off?

That could be something of a factor, but the sway brace bolts were a lot
bigger than the bolts holding the MWA to the airframe, and we were very
careful about getting them tight. Multiple inspections, et cetera.

Wasn't something said about mechanics carrying bolts around?
I remember now we use to carry spare sway brace bolts and nuts in our
truck.

We usually inspected the MWAs off of the plane, and replaced the bolts
back at the shop when necessary. Considering the size and external
placement of the sway braces, it was very easy to do a good visual
inspection before we put the pod on.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

Buzzer wrote:

Thinking about bolts shearing I wonder if it could have been like
pylon sway brace bolts that would get worn. No visible damage to the
threads, but when you went to torque them down they wouldn't be tight
against the pod. With a pod because of the length you could shake them
and get a feel for a loose sway brace bolt. Maybe 3 bolts torqued up
tight to the plate and one a hair away from the plate would decrease
the load carrying ability enough to have a pod come off?

I remain unconvinced that the ECM pod ripped off as the result
of over-G's like Chad said because any G force powerful enough
to cause AN hardware to fail catastrophically like that would most
likely result in some of the surrounding airframe structure to fail
along with it. But as the old adage goes, **** happens. Perhaps the
bolts were over-torqued and were stretched beyond limits, elongation
of the plate(s), or WTF?

Wasn't something said about mechanics carrying bolts around?
I remember now we use to carry spare sway brace bolts and nuts in our
truck.

In addition to a small assortment of tools, I sometimes carry around
a few spare pip pins, tie-down rings, tie-wraps, rubber O-rings, and
of course, bungee cords in my A/C. On the first plane I built, I found
that 032" safety wire comes in handy from time to time not just to
help secure things, but also to unplug the carb main jets in the
field.

-Mike Marron

In article ,
Mike Marron wrote:

I remain unconvinced that the ECM pod ripped off as the result
of over-G's like Chad said

....except I never claimed just that.

because any G force powerful enough to cause AN hardware to fail
catastrophically like that would most likely result in some of the
surrounding airframe structure to fail along with it.

Bad assumption, in that you think all airframes are always new, always
perfectly maintained, and perfectly designed.

But as the old adage goes, **** happens. Perhaps the bolts were
over-torqued and were stretched beyond limits, elongation of the
plate(s), or WTF?

Oh, *now* you start to get it. Took you long enough.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

"Scott Ferrin" wrote in message
...
On Thu, 18 Sep 2003 16:45:14 -0700, "Tarver Engineering"
wrote:


"Mike Marron" wrote in message
.. .
Ed Rasimus wrote:
Chad Irby wrote:

I know there were a couple of cases in Vietnam where F-4s made hard
enough turns to rip the ECM pods off...

Gotta wonder about that, since ECM pods were routinely carried in the
Sparrow missile wells. Can't imagine a situation in which the pods
suspension gear would fail. Don't say it couldn't, simply that I doubt
it.

In 250 combat missions, 150 over NVN where high threat evasions were
most likely, I never, not even once, heard of a structural failure nor
of an inadvertent separation of any piece of equipment off an
aircraft. I'm not saying it couldn't have, simply that I doubt it.

I doubt it too!

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.

Marron has no such math skills.