In a fighter jet, what is the average weight of the ejection system? In the old days, pilots had only a parachute pack. (In the really old days they might not even have that.) They had to open the canopy manually and jump out.

Today, fighter jets have zero-zero ejection seats. They can save the pilot even at zero airspeed and zero altitude. They do this with solid rockets to eject the pilot upwards.

I would like to know what is the average weight of this system for a single-pilot fighter jet? That way we can compare it's weight to the total weight of the plane and see what fraction it is.

Really the weight would include only the rockets and explosive bolts on the canopy, and I guess the ejection handle too. It would not include the weight of the seat or the pilot, as those have to be there even without an ejection system.
The F-14 manual describes the ejection system as:


  The aircraft is equipped with an automatic electronically sequenced command escape system incorporating two Navy aircrew common ejection seat (SJU-17(V) 3/A (pilot) and SJU-17(V) 4/A (RIO)) rocket-assisted ejection seats.


That means the seats are an integral part of the system.

According to this page, the weight is 228 pounds (103 kg) and it has a "maximum thrust [of] 4,800 pounds for 0.25 seconds".



A cockpit seat on a Boeing 737 weighs around 40 kg if we are to trust this replica vendor, so we can say the addition of the ejection elements adds 63 kg. Of course a 737 cockpit seat is much heavier than a WWII non-existent seat (the pilots brought their own cushions). This might be useful however if you want to compare a B-52 with and without ejection seats.

Below is an image for that ejection system, and as I gather, that's a very common (average) model found on many US aircraft.

(Click for larger size.)