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Comment by HPsquared | Hacker News Reader

I wonder if the ejection seat has different levels of acceleration depending on the situation.

I don't think so. It's a solid rocket motor, there's no modulating such things.

Many seat types have multiple distinct motors for redundancy reasons. Even if there are not, you can adjust the effective output of a solid rocket motor by modifying the nozzle configuration, and Martin-Baker has an expired patent on this.

... but even if the seat in question was able to adjust the ejection thrust (which I don't think it was), this particular situation involved ejection really close to the ground, which calls for maximum thrust.

Car airbags are basically that, and they have different levels of deployment (on a much lower budget).

When you're chosing to egress because the plane stops to know where it is or where it isn't, would you want it to decide how fast to eject? Chances are that the ejection system won't get reliable data to decide on in these situations.

I believe the only relevant factor is airspeed.

Airspeed, altitude, vertical speed.

Make it two motors, they either burn together or they burn one after the other. Neither altitude nor vertical speed is going to matter as you get the same impulse. Airspeed matters as you have to clear the tail.

I've never heard of this, but I imagine it would only make sense as a manual override used explicitly for controlled-ejection scenarios. This incident was almost one of those, but turned into an uncontrolled one.

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