Joe Broady
Airman 1st Class
- 121
- May 30, 2019
From my 1980 B-52H flight manual, here are some data on the egress systems.
For the four upward ejection seats, minimum altitude is zero, but airspeed must be at least 90 knots to get a good chute. For the two navigator seats in the lower compartment, minimum altitude is 250 feet. That figure is valid if the flight path is not descending with respect to terrain and airspeed is at least 120 knots.
Upward ejection requires that you rotate the arming levers up. They are stowed under the forward part of the armrests, and each has a latch release which must be depressed before the upward rotation. When they are rotated fully up, the hatch jettisons, and for the pilot seats, a pyro disconnects the control column and stows it forward against the instrument panel. Then you re-grip the arming levers and squeeze the triggers that are now exposed. As a safety measure, the triggers are locked until the departure of the hatch fires an initiator, so you don't hit the ceiling if the hatch fails to jettison. There's an override so you can fire the seat if the hatch has clearly departed but the initiator failed to fire.
Actually, either arming lever can fire the seat. The manual recommends you operate both simultaneously since they provide a hand hold to inhibit arm flailing.
Downward ejection is simpler. You simply pull the trigger ring between your legs. That single action jettisons the hatch and fires the seat.
There are non-ejection seats for instructor pilot, defense instructor, and instructor navigator, That last has two seats. One is forward near the navigators, but it's not stressed for crash landing, so a second seat is provided at the rear of the compartment. Thus, the B-52 has seats for nine, or it did back in 1980. I don't know about today. Years ago I was in 0050 at Edwards, and it still had a gunner's seat, occupied by a flight test instrumentation operator.
Either of the downward ejection hatch openings is what the book recommends for non-ejection bailout. Minimum altitude is 500 feet, and max speed 275 knots (250 if gear is down.) "Assume position facing forward and crouch with hands placed on the compartment floor on each side of the hatch opening. Draw arms and legs in close to body. Exit head first, faced away from the slipstream, by rolling forward and downward through the opening. Be sure to duck head and crouch as much as possible to avoid hitting forward part of hatch. No serious turbulence exists in the area inside the open hatch."
Sadly, in the recent Edwards crash it seems the emergency occurred too fast for even the upward ejection seats to save their occupants.
For the four upward ejection seats, minimum altitude is zero, but airspeed must be at least 90 knots to get a good chute. For the two navigator seats in the lower compartment, minimum altitude is 250 feet. That figure is valid if the flight path is not descending with respect to terrain and airspeed is at least 120 knots.
Upward ejection requires that you rotate the arming levers up. They are stowed under the forward part of the armrests, and each has a latch release which must be depressed before the upward rotation. When they are rotated fully up, the hatch jettisons, and for the pilot seats, a pyro disconnects the control column and stows it forward against the instrument panel. Then you re-grip the arming levers and squeeze the triggers that are now exposed. As a safety measure, the triggers are locked until the departure of the hatch fires an initiator, so you don't hit the ceiling if the hatch fails to jettison. There's an override so you can fire the seat if the hatch has clearly departed but the initiator failed to fire.
Actually, either arming lever can fire the seat. The manual recommends you operate both simultaneously since they provide a hand hold to inhibit arm flailing.
Downward ejection is simpler. You simply pull the trigger ring between your legs. That single action jettisons the hatch and fires the seat.
There are non-ejection seats for instructor pilot, defense instructor, and instructor navigator, That last has two seats. One is forward near the navigators, but it's not stressed for crash landing, so a second seat is provided at the rear of the compartment. Thus, the B-52 has seats for nine, or it did back in 1980. I don't know about today. Years ago I was in 0050 at Edwards, and it still had a gunner's seat, occupied by a flight test instrumentation operator.
Either of the downward ejection hatch openings is what the book recommends for non-ejection bailout. Minimum altitude is 500 feet, and max speed 275 knots (250 if gear is down.) "Assume position facing forward and crouch with hands placed on the compartment floor on each side of the hatch opening. Draw arms and legs in close to body. Exit head first, faced away from the slipstream, by rolling forward and downward through the opening. Be sure to duck head and crouch as much as possible to avoid hitting forward part of hatch. No serious turbulence exists in the area inside the open hatch."
Sadly, in the recent Edwards crash it seems the emergency occurred too fast for even the upward ejection seats to save their occupants.
