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

In message , Hobo
writes

At http://www.israeli-weapons.com/weapo...craft/f-15i/F-
15I.html I found this quote:

"Among other elements tested were the plane's performance at speeds
greater than Mach 2, and at maximum maneuver load at 9g."

I thought that F-15s can only make 7G turns and that they can only make
3G turns with a bomb load or the bombs tear off the mounts. What is the
correct information on these subjects?

Classified, so I don't know.

Open-source suggest a ~7.5G limit on clean Eagles armed air/air (that's
a _lot_ of turn for a big-winged big-engined fighter like the F-15).
Strike loads will be a lot lower and 3G is low but not incredible (if
you have to yank-and-bank you jettison your bombs: it's a relatively
recent idea that you fight through and press on)

--
When you have to kill a man, it costs nothing to be polite.
W S Churchill

Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk

On Wed, 17 Sep 2003 23:45:35 +0100, "Paul J. Adam"
wrote:

In message , Hobo
writes

At http://www.israeli-weapons.com/weapo...craft/f-15i/F-
15I.html I found this quote:

"Among other elements tested were the plane's performance at speeds
greater than Mach 2, and at maximum maneuver load at 9g."

I thought that F-15s can only make 7G turns and that they can only make
3G turns with a bomb load or the bombs tear off the mounts. What is the
correct information on these subjects?

Classified, so I don't know.

Open-source suggest a ~7.5G limit on clean Eagles armed air/air (that's
a _lot_ of turn for a big-winged big-engined fighter like the F-15).
Strike loads will be a lot lower and 3G is low but not incredible (if
you have to yank-and-bank you jettison your bombs: it's a relatively
recent idea that you fight through and press on)


I've read in several places that the Es are stressed for 9gs, not the
previous 7.5.

IIRC that is for a clean E.

Scott Ferrin wrote:

On Wed, 17 Sep 2003 23:45:35 +0100, "Paul J. Adam"
wrote:




I've read in several places that the Es are stressed for 9gs, not the
previous 7.5.



--
AL
New anti-terrorism tool, "Fly naked"
http://www.alfredivy.per.sg

Info sounds odd to me. 7.5 G is a standard operating limit for USAF
fighters. The F16's 9G in non-standard. Both limits offer a 1.5 safety
factor. Again, standard. 3G limit for carrying bombs is awfully low.
We used 4G as a standard pull-out in the F4, 5g if we were pressing
for greater accuracy. I managed to pull 8 once in an extremity (we
were getting hosed) and nothing fell off. Continued with the mission
and the rest of the bombs came off as designed. As for the 15
sustaining 9G, I shouldn't wonder, considering the excess power the
aircraft has and also that no altitude was mentioned. I do know from
personal experience that at sea level the F104A and the F4 would
sustain 7G at 500KIAS as long as the fuel lasted (or the crew). The
F15 has a lot more excess power than either of those aircraft.
Walt BJ

Walt BJ wrote:

Info sounds odd to me. 7.5 G is a standard operating limit for USAF
fighters. The F16's 9G in non-standard. Both limits offer a 1.5 safety
factor.

The F-15A/B had a +7.33G limit. The F-15C/D was given an overload warning
system that allows it to "maneuver safely to the 9G limit of the airframe
at all design gross weights", or so Dennis Jenkins writes in the Warbirds
Tech Manual for the F-15. At least some F-15As were modified to allow
them to do the same; ISTR this may have involved some minor airframe
strengthening.

Again, standard. 3G limit for carrying bombs is awfully low.
We used 4G as a standard pull-out in the F4, 5g if we were pressing
for greater accuracy.

ISTR that the F-15's MER-200s were designed for +7.33G max., while the
previous generation's (i.e. your F-4) were designed for 5G. I couldn't
say what the CFTs were rated at.

Guy

On 17 Sep 2003 19:49:33 -0700, (Walt BJ) wrote:

Info sounds odd to me. 7.5 G is a standard operating limit for USAF
fighters. The F16's 9G in non-standard. Both limits offer a 1.5 safety
factor. Again, standard. 3G limit for carrying bombs is awfully low.
We used 4G as a standard pull-out in the F4, 5g if we were pressing
for greater accuracy. I managed to pull 8 once in an extremity (we
were getting hosed) and nothing fell off.

8gs? No wonder the F-4C wing tips developed cracks.G

(Walt BJ) wrote:


We used 4G as a standard pull-out in the F4, 5g if we were pressing
for greater accuracy. I managed to pull 8 once in an extremity (we
were getting hosed) and nothing fell off.

Got this among a list of quotes from a reasonably erudite fighter
pilot:

"The aircraft G-limits are only there in case there is another flight
by that particular airplane. If subsequent flights do not appear
likely, there are no G-limits."

Makes a lot of sense to me.



Ed Rasimus
Fighter Pilot (ret)
***"When Thunder Rolled:
*** An F-105 Pilot Over N. Vietnam"
*** from Smithsonian Books
ISBN: 1588341038

On Thu, 18 Sep 2003 13:47:22 GMT, Ed Rasimus
wrote:

(Walt BJ) wrote:


We used 4G as a standard pull-out in the F4, 5g if we were pressing
for greater accuracy. I managed to pull 8 once in an extremity (we
were getting hosed) and nothing fell off.

Got this among a list of quotes from a reasonably erudite fighter
pilot:

"The aircraft G-limits are only there in case there is another flight
by that particular airplane. If subsequent flights do not appear
likely, there are no G-limits."

Makes a lot of sense to me.



REad of a Skyray pulling 12 Gs and wrinked the wing. Don't know if it
ever flew again. And also of a Tomcat that did a NEGATIVE 8+ (they
didn't have a choice). I think the Tomcat flew again.

"Scott Ferrin" wrote

REad of a Skyray pulling 12 Gs and wrinked the wing. Don't know if it
ever flew again. And also of a Tomcat that did a NEGATIVE 8+ (they
didn't have a choice). I think the Tomcat flew again.

Humans aren't rated for -8 G's for over 1 second :-)

In article ,
Scott Ferrin writes:
On Thu, 18 Sep 2003 13:47:22 GMT, Ed Rasimus
wrote:

(Walt BJ) wrote:


We used 4G as a standard pull-out in the F4, 5g if we were pressing
for greater accuracy. I managed to pull 8 once in an extremity (we
were getting hosed) and nothing fell off.

Got this among a list of quotes from a reasonably erudite fighter
pilot:

"The aircraft G-limits are only there in case there is another flight
by that particular airplane. If subsequent flights do not appear
likely, there are no G-limits."

Makes a lot of sense to me.



REad of a Skyray pulling 12 Gs and wrinked the wing. Don't know if it
ever flew again. And also of a Tomcat that did a NEGATIVE 8+ (they
didn't have a choice). I think the Tomcat flew again.

That would have been Bob Rahn, in one of hte prototype XF4Ds,
discovering thr Ford's pitchup tendency when pulling G while
decelerating through the transonic range. (An F4D wasn't on most days,
supersonic in level flight. Clean, with a good airplane, maybe, but
otherwise, not. It could be dived to Mach 1.2-1.3 fairly routinely,
though). Since one of teh Skyray's innovations was a rather unique
constuction method using a very thin skin over lots of small stringers
and spars, the airplane was not only well and truly bent, but ended up
wrinkled like a prune. (It's worth noting that one of the changes
that occurred when turning the F4D Skyray into the F5D Skylancer was a
more conventional type of construction.)

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster