Flanker vs F-15

"Boomer" wrote in message
...
I'm no aerodynamicist but I've been running some numbers and noticed some
interesting things.
The SU-27 is credited with being more manueverable than F-15 and yet F-15
has a higher TTW number (except at gross) and a lower wing loading by a
large margin (again except at gross). The SU should develope more body
lift
than Eagle, but at best it looks like a wash at low altitudes, with Eagle
turning better than SU at altitude.
Any thoughts? Am I missing something large here? The Su's lerx's and
higher
aspect wing should make a positive differance at low level and low speeds
but I dont think it would make up for the other numbers. Eagle should have
a
20% better wing loading and about a 14% better TTW number.

The Su has a pull-through fuction on the fbw ISTR. Might be a factor?

John

John Mullen wrote:

The Su has a pull-through fuction on the fbw ISTR. Might be a factor?

Probably not since the the F-15C isn't FBW and only has an overload
warning function. You can over G a F-15C.

Michael Kelly, Bone Maintainer


John

yes Flankers have a switch which over rides the FBW limits, that's the only
way they can do the "Cobra" manuever. As I recall F-15s started out with
hydro controls with FBW as back up, then later models went fully fly by
wire.

--



Curiosity killed the cat, and I'm gonna find out why!
"Michael Kelly" wrote in message
m...

John Mullen wrote:

The Su has a pull-through fuction on the fbw ISTR. Might be a factor?

Probably not since the the F-15C isn't FBW and only has an overload
warning function. You can over G a F-15C.

Michael Kelly, Bone Maintainer


John

On Thu, 25 Mar 2004 02:44:04 -0600, "Boomer"
wrote:

yes Flankers have a switch which over rides the FBW limits, that's the only
way they can do the "Cobra" manuever. As I recall F-15s started out with
hydro controls with FBW as back up, then later models went fully fly by
wire.

The F-15 started as conventional with conventional backup and an
analog FCS. It eventually went to a digital FCS, but not to FBW.

The E might be FBW, but the A-D aren't.

Mary

--
Mary Shafer Retired aerospace research engineer

On Thu, 25 Mar 2004 02:44:04 -0600, "Boomer" wrote:

yes Flankers have a switch which over rides the FBW limits, that's the only
way they can do the "Cobra" manuever.

Or you can simply apply an extra 33lb of stick force.


--
Steve.

"Steve" wrote in message
...
On Thu, 25 Mar 2004 02:44:04 -0600, "Boomer" wrote:

yes Flankers have a switch which over rides the FBW limits, that's the
only
way they can do the "Cobra" manuever.

Or you can simply apply an extra 33lb of stick force.

That is a lot, the F/A-18 breaks out at 20 lbs.

"Tarver Engineering" wrote in message ...
"Steve" wrote in message
...
On Thu, 25 Mar 2004 02:44:04 -0600, "Boomer" wrote:

yes Flankers have a switch which over rides the FBW limits, that's the
only
way they can do the "Cobra" manuever.

Or you can simply apply an extra 33lb of stick force.

That is a lot, the F/A-18 breaks out at 20 lbs.

Not true - you are confusing this with aoa feedback in the stick above
20 alpha -to get more g than the programmed limiter (usually 7.5) you
must engage the paddle switch, which will then give you 33% more g.

"monkey" wrote in message
om...
"Tarver Engineering" wrote in message
...
"Steve" wrote in message
...
On Thu, 25 Mar 2004 02:44:04 -0600, "Boomer"
wrote:

yes Flankers have a switch which over rides the FBW limits, that's
the
only
way they can do the "Cobra" manuever.

Or you can simply apply an extra 33lb of stick force.

That is a lot, the F/A-18 breaks out at 20 lbs.

Not true - you are confusing this with aoa feedback in the stick above
20 alpha -to get more g than the programmed limiter (usually 7.5) you
must engage the paddle switch, which will then give you 33% more g.

I am refering to the force required to move the stick. My F-18 (AV6) had a
swich on the left panel to cut out the FCS much like the MiG.

"Michael Kelly" wrote in message
m...

John Mullen wrote:

The Su has a pull-through fuction on the fbw ISTR. Might be a factor?

Probably not since the the F-15C isn't FBW and only has an overload
warning function. You can over G a F-15C.

Michael Kelly, Bone Maintainer

Actually fly-by-wire aircraft can be over-Gd -- it happens to F-16s all the
time.

The F-15, while not "fully" fly-by-wire, has a primary flight control system
that is FBW (called the CAS, or Control Augmentation System) and a
hydromechanical backup system.

R Haskin wrote:
Actually fly-by-wire aircraft can be over-Gd -- it happens to F-16s all
the
time.

Yabbut, isn't that a case of a Lawn Dart pulling max G and
then hitting turbulence, etc.?


Jeff