Flanker vs F-15

"David E. Powell" wrote in message ws.com...
There are two really important questions:

1. What are the other odds? (AWACS, support aircraft, SAM defenses, range to
bases, numbers on each side, etc.)

I wonder how long it would take a fuel-heavy Flanker to dump down to
ACM weight. Doesn't it carry a LOT more internally than an Eagle, at
least for ferry or long range ops?

On 26 Mar 2004 06:46:06 -0800, (Jeb Hoge) wrote:

"David E. Powell" wrote in message ws.com...
There are two really important questions:

1. What are the other odds? (AWACS, support aircraft, SAM defenses, range to
bases, numbers on each side, etc.)

I wonder how long it would take a fuel-heavy Flanker to dump down to
ACM weight. Doesn't it carry a LOT more internally than an Eagle, at
least for ferry or long range ops?

Nope. So far as I know, no Russian fighter carries anything like the
internal fuel a US fighter does. That's because the aircraft weren't
expected to fly long distances because they use ground control.

Actually, it's true of European fighters, too, which is why Australia
and Canada buy US aircraft. Big countries, long legs.

I read this in one of the British aircraft magazines a few years back,
in an article comparing the F-18 with the similar Russian airplane.
At least once and a half as much fuel internal to the Hornet and the
author made the comment that the US had, historically, always carried
more internal fuel in its fighters, citing WW II aircraft numbers as
well.

Mary

--
Mary Shafer Retired aerospace research engineer

On Thu, 25 Mar 2004 05:41:52 -0500, "R Haskin"
wrote:


"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.

All modern FCSs are electronic, not mechanical or hydraulic, but we
don't consider them to be FBW. We just consider them to be analog or
digital FCSs. However, it's possible to have hydraulic or mechanical
FCSs.

The point is that FBW is strictly between the pilot and the control
surfaces. That's it. Nothing to do with the feedback control in the
flight control system. After all, the SR-71 was summing electric
inputs from the FCS with the push-rod and cable inputs from the pilot
back in the '60s.

You can have FBW without having a feedback control FCS, not that
anyone does, and you can have an FCS without having FBW, which the
F-15 does and the SR-71 did. Or you can have both, which the F-16 and
F-18 do.

Mary

--
Mary Shafer Retired aerospace research engineer

"Mary Shafer" wrote in message
...
On Thu, 25 Mar 2004 05:41:52 -0500, "R Haskin"
wrote:


"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.

All modern FCSs are electronic, not mechanical or hydraulic, but we
don't consider them to be FBW. We just consider them to be analog or
digital FCSs. However, it's possible to have hydraulic or mechanical
FCSs.

The part that makes the system FBW is a distinction between cable tripped
valves, or electric valves. (current, or hydraulic)

The point is that FBW is strictly between the pilot and the control
surfaces. That's it. Nothing to do with the feedback control in the
flight control system. After all, the SR-71 was summing electric
inputs from the FCS with the push-rod and cable inputs from the pilot
back in the '60s.

The 747-200 and the DC-10 are termed "hybrid FBW" for having cable driven
hydraulic valves controlled electrically.

You can have FBW without having a feedback control FCS, not that
anyone does, and you can have an FCS without having FBW, which the
F-15 does and the SR-71 did. Or you can have both, which the F-16 and
F-18 do.

An the Boeing 717.

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.

"Mary Shafer" wrote in message
...
On 26 Mar 2004 06:46:06 -0800, (Jeb Hoge) wrote:

"David E. Powell" wrote in message
ws.com...
There are two really important questions:

1. What are the other odds? (AWACS, support aircraft, SAM defenses,
range to
bases, numbers on each side, etc.)

I wonder how long it would take a fuel-heavy Flanker to dump down to
ACM weight. Doesn't it carry a LOT more internally than an Eagle, at
least for ferry or long range ops?

Nope. So far as I know, no Russian fighter carries anything like the
internal fuel a US fighter does. That's because the aircraft weren't
expected to fly long distances because they use ground control.

Actually, it's true of European fighters, too, which is why Australia
and Canada buy US aircraft. Big countries, long legs.

I read this in one of the British aircraft magazines a few years back,
in an article comparing the F-18 with the similar Russian airplane.
At least once and a half as much fuel internal to the Hornet and the
author made the comment that the US had, historically, always carried
more internal fuel in its fighters, citing WW II aircraft numbers as
well.

Mary

--
Mary Shafer Retired aerospace research engineer


Mary, you are WAY out on this one.

The internal fuel load of a Su-27 Flanker is 9,400kg, on the F-15C it s
5,950kg (or 6,103 depending on source), the F-18 is 4,900kg.

Range without drop tanks is 3,680km for the Su-27, 1,970km for the F-15C &
2,200 for the F-18.

The magazine you quote must have been comparing a MiG-29 (which is short
legged) with the F-18 (which isn't exactly long-legged), but to state that
no Russian
fighter carries anything like the internal fuel of a US fighter is no longer
true.

The Su-27 was designed to patrol the vast skies over Russia - and has the
internal fuel to do so.

Indeed, the Su-27 flown by Anatoly Kvotchur of the 'Test Pilots' display
team, regularly flies non-stop Moscow-UK to attend our airshows - and then
does an aerobatic
display before landing !!!

Ken Duffey

Flanker Freak & Russian Aviation Enthusiast.

On Fri, 26 Mar 2004 22:04:59 -0000, "Ken Duffey"
wrote:

"Mary Shafer" wrote in message
.. .
On 26 Mar 2004 06:46:06 -0800, (Jeb Hoge) wrote:

"David E. Powell" wrote in message
ews.com...
There are two really important questions:

1. What are the other odds? (AWACS, support aircraft, SAM defenses,
range to
bases, numbers on each side, etc.)

I wonder how long it would take a fuel-heavy Flanker to dump down to
ACM weight. Doesn't it carry a LOT more internally than an Eagle, at
least for ferry or long range ops?

Nope. So far as I know, no Russian fighter carries anything like the
internal fuel a US fighter does. That's because the aircraft weren't
expected to fly long distances because they use ground control.

Actually, it's true of European fighters, too, which is why Australia
and Canada buy US aircraft. Big countries, long legs.

I read this in one of the British aircraft magazines a few years back,
in an article comparing the F-18 with the similar Russian airplane.
At least once and a half as much fuel internal to the Hornet and the
author made the comment that the US had, historically, always carried
more internal fuel in its fighters, citing WW II aircraft numbers as
well.

Mary

--
Mary Shafer Retired aerospace research engineer


Mary, you are WAY out on this one.

The internal fuel load of a Su-27 Flanker is 9,400kg, on the F-15C it s
5,950kg (or 6,103 depending on source), the F-18 is 4,900kg.

Range without drop tanks is 3,680km for the Su-27, 1,970km for the F-15C &
2,200 for the F-18.

The magazine you quote must have been comparing a MiG-29 (which is short
legged) with the F-18 (which isn't exactly long-legged), but to state that
no Russian
fighter carries anything like the internal fuel of a US fighter is no longer
true.

And while the Foxhound isn't exactly a "fighter" it carries a buttload
of fuel too.

Mary, you are WAY out on this one.

The internal fuel load of a Su-27 Flanker is 9,400kg, on the F-15C it s
5,950kg (or 6,103 depending on source), the F-18 is 4,900kg.

Range without drop tanks is 3,680km for the Su-27, 1,970km for the F-15C &
2,200 for the F-18.

Yeah, I was about to say the same thing.

Su-27 can carry LOTS of fuel.


Ron
Tanker 65, C-54E (DC-4)

Boomer wrote:

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.

My guess would be that in addition to the LERX it's the auto LEF, vs. a fixed
LE, high-camber wing. The latter is lighter, but you'll note that every
maneuverable fighter designed after the F-15 has gone with LEF. McAir's
designers considered LEF, but decided against them on cost/weight grounds, and
maybe on performance grounds in a certain part of the envelope. I've always
wanted to ask whoever made the decision if, given the benefit of hindsight,
they'd have gone the other way.

Guy