Roll Stability in lifting body and flying wing aircraft

IIUC, the B-2 and F-117 rely on continuous feedback and control,
they could not be flown without computers.

So how do lifting bodies and Flying Wings like the facetmobile or the
Chance-Vought V-173 "Flying Flapjack" maintain roll stability? They
appear to have no or negative dihedral.

--

FF

"Fred the Red Shirt" wrote in message
om...
IIUC, the B-2 and F-117 rely on continuous feedback and control,
they could not be flown without computers.

So how do lifting bodies and Flying Wings like the facetmobile or the
Chance-Vought V-173 "Flying Flapjack" maintain roll stability? They
appear to have no or negative dihedral.

--

FF

Having helped build and test fly a flying wing, maybe I can help.

To the roll stability question there are two answers.

1. You don't really need roll stability as long as you don't have real roll
instability. Pilots can easily keep the wings level.

2. Sweep back has the same effect as dihedral. Sometimes the dihedral
effect of sweep is so strong that anthedral (negative dihedral) is needed to
give the aircraft maneuverability.

Pitch stability comes mainly from the airfoil choice. Or, in the case of
swept back flying wings, from wing twist. Sometimes, it's a combination of
both.

Yaw stability and control is the big problem of flying wings. Here,
computer stability augmentation is very useful.

Bill Daniels

A few months ago I read a fantastic article about this very subject in an
aviation magazine, but for the life of me I can't remember which one. It was
written by one of the test pilots who flew Northrop's flying wings. VERY,
VERY interesting reading. It was one of the magazines that specialized on
WWII aircraft subjects. Anybody else remember seeing this?

"Bill Daniels" wrote in message
news:Es4sd.605454$mD.500572@attbi_s02...

"Fred the Red Shirt" wrote in message
om...
IIUC, the B-2 and F-117 rely on continuous feedback and control,
they could not be flown without computers.

So how do lifting bodies and Flying Wings like the facetmobile or the
Chance-Vought V-173 "Flying Flapjack" maintain roll stability? They
appear to have no or negative dihedral.

--

FF

Having helped build and test fly a flying wing, maybe I can help.

To the roll stability question there are two answers.

1. You don't really need roll stability as long as you don't have real
roll
instability. Pilots can easily keep the wings level.

2. Sweep back has the same effect as dihedral. Sometimes the dihedral
effect of sweep is so strong that anthedral (negative dihedral) is needed
to
give the aircraft maneuverability.

Pitch stability comes mainly from the airfoil choice. Or, in the case of
swept back flying wings, from wing twist. Sometimes, it's a combination
of
both.

Yaw stability and control is the big problem of flying wings. Here,
computer stability augmentation is very useful.

Bill Daniels