The main reason why ejection seats eject up is because many times there is not altitude for a downward ejection when something goes wrong. Many
military aircraft have what is called a zero-zero ejection seat. A zero-zero seat enables a pilot or crewman to eject from an aircraft that is
stationary on the ground. This can come in handy in the event of a fire on the ground. The problem with a sideways ejection is that there is no way
to support the human body against the forces necessary for an ejection.
Helicopters are unique in the fact that they can make an emergency landing with very little foreward airspeed. A small Cessna still needs a couple of
hundred feet to make an emergency landing. A helicopter only needs a small clearing in which to land. I spent a few years as a helicopter crewman in
the US Navy and walked away from a few landings where they trucked away the helicopter to the junkyard. The seats are specially engineered to allow a
person to walk away from a very hard landing. We has a catastrophic Main Gearbox failure about 150 feet off of a concrete pad. We hit HARD! My seat
collapsed downward and I ended up with my knees against my chin, but other than a few streatched muscles I was fine.
In my opinion the only thing an upward firing ejection seat in a helicopter is good for is a large economy pepperoni slicer. If you need the seat
that means that the aircraft has failed, what makes you think that the mechanism to eject the blades will work??