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Cool description. Thanks.

That was the short version. Let me see if I can conjour up more details.

Assuming the front guy, pilot, pulls the D-ring:

1) Back seat canopy blown off with 1500psi air from the reservour.

2) A charge fires, snatching the pilots shoulders tight up against the seat, least he be bent over and it breaks his back. Also his feet are snatched back to the seat off the rudder pedals.

3) Cannon goes off in the telescoping tube (I'm sure there are very official names for this stuff, I just don't remember), burning the extra propellant as it goes up.

4) Seat reaches end of rope line, trips rocket sear, rocket goes off.

5) About 2-4 seconds later, fuse on the drouge chute goes off, firing a shotgun shell sized explosive and a metal rod weight about the size of your thumb and 10 inches long up over the seat, draging out the drogue.

6) When the seat is below 10k feet, or the pilot pulls a handle on the seat, the drouge releases and pulls out the main chute. At the same time the pilots harness is cut from shoulders, wast, and legs, releasing the seat, but retaining the first aid kit he's sitting on.

That's one seat. The other does virtually the same.

I'm not totally certian about the Martin Baker F4 seat, but I know in some seats there's a gyro that will aim the rocket so that if the pilot punches out with the airplane upside down, it will turn the seat right side up so he doesn't hit the ground.

When below 10k feet, all that happens in 3-4 seconds. The time between the front guy pulling the handle to when the both pilots are out of the AC is 2-3 seconds. I'm sure that front seat guy thinks it's much longer.

That's all from 30 year old memory, so nobody gripe if I've got a detail wrong.

Excellent description for the F-4.

For the ACES II seat, the sequence is about the same and the seat has a pitot tube and a gyro.

The pitot tube determines if the ejection is
a) A hi-speed, hi-altitude ejection. If this is the case, the pilot chute is deployed and the piot remains in the seat, facing down, as he races to wards the ground. When dropping through about 14,000 feet, the main chute deploys and he is separated from the seat.
b) Loe-speed, low-atitude ejection. Less than 250 kts and low altitude and the pilot is immediately flung from the seat and the chute deploys.

The gyro is to stabilize the trajectory of the seat and does not have the ability to make an upside down ejection right side up. The seat fires, the gyro gets about 20,000 rpm by the time the seat reaches the top of the rails. The gyro gives the seat a true zero-zero (no airspeed, no altitude) capability. The body slumps and the center of gravity shifts when the ejection happens so the gyro adjusts the rocket motor to ensure the ejection flight path remains true.