Contour Enthusiasts Group Archives Forums General Common Interests Fighter Jet enthusiasts, why can't a jet recover from a flat spin?

Anyone got a copy of Jane's ATF??

I've always loved how evil the Phantom looks...

in some instances of flat spin, the direction of airflow past or into the engine inlet is of such that it can casue a compressor stall or in severe cases casue the engine to flame out causing complete loss of power. In this case the pilot has a limited ammount of control capabilities and a limited ammount of time as all aircraft systems are operating off battery power.

Basically during a flat spin or departure as it is sometimes referred to, the aircraft takes on the same flight caracteristicts as a leaf falling from a tree.

A flat spin is sometimes un-recoverable becasue as the aircraft falls straight down the airflow over the flight controls, (rudder, elevators and ailerons) is not in such a manner that allows these control surfaces to impart a force to the airfame to casue a change in attitude.

There is currently a system developed and used in some military applicatons and available for civilian aviation as well. The system is basically a parachute that is deployed by a small rocket motor. The parachute is attached to the tail of the aircraft, and when deployed causes drag which slows the aft portion of the aircraft casuing it to take a nose down attitude. When the node down attitude is established the pilot will allow gravity to accelerate the aircraft with the parachute maintaining the dive formation until safe manuvering speeds are reached. At this time the pilot can restart the engine(s) if necessary and jettison the parachute, then recover from the dive and make a safe landing.

There is a documented incident involving a flat spin of a military aircraft. When the pilot realized he/she was not able to correct the aircraft and their life was in danger they ejected. When the rocket motor of the ejection seat fired and propelled the officer away from the aircraft, Newton's third law (for every action there is an equal and opposite reaction) took effect, the aircraft which still has all its systems operting with engines at low power, took a nose down attitude, accelerated, and the flight computers which were still operational corrected the aircraft, but becasue of the low power setting of the engines was unable to maintain level flight. The aircraft decended until making a rough gear up landing in a field all by itself.

What JSMITH said.... Dead on!

Another word for "crashed in a ball of fire"? Or does that mean it actually landed in one or two pieces? If it did, that's pretty amazing!!

whats a flat spin? the plane is flying flat and is turning about the.... Z axis? the one thats perpendiclar (sp) to the ground? how in the hell would a plane ever start a flat spin?

Twin engine aircraft (jet), one engine flames out, the other induces a torque about a vertical line through the center of mass, and the aircraft spins out into a flat spin. Think of the aircraft rotating as if it were a frisbee.

just like the compressor stall mentioned before. Going back to the F-14, I believe that's why it was so prone to spinning. At high angles of attack, one engine would stall which destabilized the aircraft. After better engines were installed, the problem wasn't as bad. Someone want to check my info?

IIRC, in the F/A-18 to recover its full right rudder and pus the stick to the left........

Hmmmm, maybe in a fighter on burner, with a high torque moment vs. vehicle weight ratio, but in general, twin-engine aircraft (and I confess my knowledge is confined primarily to large civil aircraft) are designed to handle an engine-out situation without too much drama. So a 737/757/767/777 suffering an engine shutdown even during takeoff should be controllable. I think the issue is that the F-14 gets outside its flight envelope, enters a flat spin, and THEN the engines suffer compressor stalls because of the disrupted airflow entering the intakes; although at that point the engines are the least of the crew's worries; it's punching out and trying to come up with a reasonable excuse to the big boss for losing the aircraft.