The Early Days

World War I fighter planes were literal death traps. They were made of wood and covered in fabric coated with highly flammable varnish. The pilot sat in a wicker seat, often right on top of the gas tank. A pilot faced with a burning aircraft had three rather unpleasant options:

1. Ride it in and die a horrible death.

2. Jump out and die a slightly less horrible death.

3. Use his sidearm and take the quick way out.

The Allies were very reluctant to adopt parachutes for air crews. They believed that a pilot might opt to jump from a damaged aircraft rather than try to save it. There also wasn't really room for a parachute in the very cramped WWI cockpits. Getting past all those struts and wires in a bailout situation was also problematic.

The Germans, ahead of the curve as usual, started equipping pilots with parachutes late in the war. This was based on a type successfully used by balloon crews. It was better than nothing but like most "beta versions" it had problems. The canopy portion of the parachute was actually stored in a compartment behind the pilot and tended to get caught up in the aircraft.

In 1919 the US Army developed the "Type A" parachute, which is the archetypal "round" parachute still in use today. This was a fully self-contained parachute worn on the pilot's back. In the early days they were made of silk, hence the popular saying. Besides, "hit the nylon!" just doesn't have the same ring to it.

1920s through World War II

Through the 1920s all the way through World War II "hitting the silk" was the airman's best chance of survival. Many crewmen were saved by their parachutes. Many others weren't. It still wasn't a perfect system.

A crew member of a stricken aircraft had to:

1. Open a canopy or escape hatch, which might be jammed shut at this point, especially if there was battle damage.

2. Fight his way out past the slipstream. At higher speeds this could be almost impossible.

3. Get out before the plane wrapped up in a spin so badly that the G forces pinned them inside.

4. Not hit part of the airplane on the way out. The P-38's "cheese knife" horizontal stabilizer was notorious for this.

This is one place where the movies sometimes get it right. In The Battle of Britain there is a dramatic scene where a pilot desperately fights to open the canopy of his burning Spitfire. In Map of the Human Heart (great movie if you can find it) a crewman has to claw his way out of a plummeting Lancaster bomber.

The First Ejection Seats

As aircraft speeds increased, it was realized that something better was going to be needed. The Germans (again!) developed the first ejection seats late in the war. Allied pilots reported seeing German pilots "popping out of" their planes after being shot down.

By the time of the Korean War, ejection seats had become standard equipment for most jet fighters and bombers. These first-generation seats were a big improvement over manually bailing out but they had some serious limitations.

The early ejection seats used either compressed air or a small explosive charge to send the seat and pilot up a set of rails and out of the aircraft. They had just enough "oomph" to clear the tail of the airplane and not much more. They also required the pilot to manually jettison the canopy and manually separate himself from the seat after ejecting. Below 1000 feet the odds of successfully were pretty slim and at least 2000 feet was preferred.

The F-86 seat depicted is fairly representative of a first generation ejection seat. It would get you out of the airplane but that was it. The pilot had to manually jettison the canopy and manually separate from the seat.



F-86 Ejection Seat

Second Generation

As aircraft performance improved by leaps and bounds in the mid to late 1950s designers realized that better ejection seats were going to be required.

The F-104 is a perfect example. The early "ballistic" seats couldn't clear the Starfighter's high tail. The solution? Put a downward firing ejection seat in it! Brilliant! Wile E. Coyote is alive and well and working for Lockheed.



Early downwards ejection seat test.

Well, this worked about as well as it sounds. The downward firing seats claimed the lives of several pilots. They were replaced with rocket powered upward firing seats as soon as they became available.

To this day B-52 navigators live with downward firing seats, but there's no other direction for them to go.

These late 1950s, early 1960s models are what I would consider the first "modern" ejection seats. They used a rocket motor to propel the pilot high above the stricken aircraft instead of a simple ballistic charge.

Most importantly - the entire ejection sequence after pulling the handles was automatic. All that was required of the pilot was pulling the handles. After that, even if he blacked out, the entire process down to opening the parachute was automatic.

Some seats, like the Martin Baker seat used in the F-4, would even pull your legs inwards to keep them from hitting the cockpit on the way out. An F-4 Pilot or back seater wore cuffs around their ankles that connected to the seat via lanyards. Some versions of the F-104 had a similar setup except the pilot actually wore spurs that attached to lanyards.

By the mid 1960s some seats even had "zero zero" capability. These seats could be used from an aircraft at zero altitude and zero airspeed. You could be sitting in a parked airplane and safely eject - probably getting one swing in the parachute followed by a feet-knees-face parachute landing. Hey, you're alive, quit complaining.



Early zero-zero seat test. That's a real person in there, by the way.

While a big improvement over earlier ejection seats, the 1960s vintage models still had some limitations.

Stability was a big problem. The rocket powered seats had a tendency to tumble because the center of gravity depended on who happened to be sitting in it. This could make the man-seat separation difficult. Chuck Yeager got whacked by his seat after ejecting from an F-104. This was fairly accurately depicted in the movie The Right Stuff.

They tried to solve this problem using drogue parachutes or other aerodynamic devices with some degree of success. The F-100 had a novel approach. An inertia reel at each corner of the seat played out a line that stayed attached to the airplane. Since each reel was supposed to play out at the same time, the seat would stay relatively stable. At least they were thinking in the right direction.

Escape Capsules

As aircraft speeds started reaching Mach 2 in the late 1950s designers started experimenting with escape capsules.



B-58 Escape Capsule

B-58 Escape Capsule in open and closed positions.

XB-70 Escape Capsule Test

XB-70 Capsule with parachute deployed. This may be from the actual crash of the 2nd XB-70 prototype.

A B-58 ejection seat was enclosed within a large clam-shell. Prior to ejecting the doors would close and encapsulate the crew member. Then the entire "pod" would eject.These never really lived up to expectations. They added weight and complexity and could close on parts of the crew member (bad) during a high G ejection.During the only ejection from the XB-70 one pilot didn't make it out and the other was seriously injured.Some version of the MiG-21 had a canopy that was hinged to the top of the pilot's ejection seat and would fold down to protect his body. I have no idea how well this worked in practice. I would guess it might complicate man-seat separation. If anyone here has punched out of a MiG-21 let me know.

The F-111 and the B-1A (prototype) went a step further and would eject the entire cockpit. The F-111 cockpit would come down like an Apollo space capsule and (hopefully) the landing would be cushioned by an airbag that inflated underneath it.



F-111 Crew Module Test

From what I'm told, even if it worked correctly, the capsule came down pretty hard and back injuries were common. Most '111 drivers I talked to said they would have preferred a standard ejection seat.

The one person I know who actually used one had to spend some time in the hospital with back injuries.



F-111 Crew Module after ejection.

The thing is, if something happens to the plane at Mach 2, it probably won't be going Mach 2 for very long. The many drawbacks of the escape capsule probably outweigh its benefits. Like everything else in aviation, it's usually a trade-off. File this one under "seemed like a good idea at the time".

Interestingly enough, SR-71 crew members lived with fairly standard ejection seats. The space suit worn by crew members was considered to be protection enough.

Third Generation

Fast forward to the late 1970s/early 1980s and we see third generation ejection seats like the ACES II seat favored by the USAF and the Martin Baker MK10 seat favored by the US Navy and the UK.



MiG-29 Pilot Ejecting - Note the direction of the seat is dependent on aircraft attitude at the time of ejection.

The newer seats offer improved stability, the ACES II seat actually has a second rocket which gimbals to keep the seat stable.

The third generation seats are also "smart". They contain airspeed and altitude sensors that trigger different ejection modes. The ACES II seat, for example, has three modes low speed/low altitude, medium speed, and high speed/high altitude.

In a low-speed/low-altitude ejection, the seat will command man-seat separation and parachute deployment as soon as possible.



Martin Baker seat during a low altitude ejection from a CF-18 Hornet.

These advances give the newer seats a larger "ejection envelope". The envelope is the all important range of airspeed and altitude in which the seat can save you. Eject "out of the envelope" and it's probably going to be messy.

So what makes this so important? Let's suppose your aircraft is falling at a high rate of speed. The ejection seat needs to overcome all of that downward velocity before it can go up. Unlike the cartoons, when you get shot of a plane falling at 10,000 feet per minute you are also falling at 10,00 feet per minute.

If you're coming down that fast even something like an ACES II may need 500 feet of altitude to do its thing.

I got to check out in the ACES II seat for my F-15 back seat ride. The technicians assured me it was an extremely capable seat. Anyone who's flown an aircraft equipped with it could tell you more. I do know that it has saved an awful lot of lives since it's been in service.

Let's look at a hypothetical ejection scenario

Since I'm familiar with the T-38 I'll use its second-generation seat as an example.

This picture shows a T-38 ejection seat minus the parachute (worn on the pilot's back) and the survival kit (seat cushion). Note the two yellow ejection handles.



T-38 Cockpit

This seat has recently been replaced with a more modern unit, but this is what I remember it having.

Suppose your flying along (solo) in your T-38 at 40,000 feet and .90 mach when "BANG!".

Master Caution Light

Fire Light (left or right engine, doesn't matter)

Both hydraulic pressures are rolling back

Flight controls are becoming unresponsive

Well our day just took a turn for the worse. Sounds like an engine just went in a very big way and maybe took out the hydraulics as well.

Now what was the Boldface procedure for engine fire in flight? Oh yeah, that's it:

THROTTLE - IDLE

THROTTLE - OFF, IF FIRE LIGHT REMAINS ON

IF FIRE IS CONFIRMED - EJECT

Based on that bright red glow behind the cockpit I'd say it's confirmed. Time to get out!

OK, make sure you're sitting straight up against the seat. Don't want to snap your back or neck here. Get your feet off the rudder pedals and get them back against the seat. Tuck those elbows in tight. Don't want to leave any parts in the cockpit.

Reach down with both hands, grab the yellow handles and:

HANDGRIPS - RAISE

Nothing..............oh crap................bang!

(people who have ejected have often describe the .5 seconds between pulling the handles and the seat actually firing as seeming to take a very long time)

The first thing to go is the canopy. If not, we can eject through the canopy in this plane. Small explosive charges called "initiators" are firing in sequence, the hot gases from one igniting the next. One of them has just fired an inertia reel, pulling your shoulder straps tight.



Seat firing through the canopy. I'm not sure but I think this is an F-4 cockpit.

Next another small explosive charge under the seat fires. This is just enough to get you moving up the rails and to ignite the rocket. Every mule that's ever lived kicks you in the butt as the rocket fires with a force of 15 G's or so.

Some of the Soviet ejection seats had a spine-crushing 20-22 G's! Ouch comrade! That's gonna sting a little bit!

As you leave the cockpit you are now in a very hostile environment. The temperature is -42C. Your body is subjected to a 400 mph wind blast. Any loose equipment may turn into a deadly projectile. That loose flap of seatbelt you forgot to tuck in is now flapping in the wind and trying to shred your skin. You're lucky today - your helmet and oxygen mask stay on.

Things start to happen very quickly now. The rocket propels you maybe 100 feet above your burning aircraft. A small drogue parachute fires, stabilizing and slowing the seat. Another initiator fires, opening your lap belt. The next one fires the man-seat separator, snapping tight a vertical strap that catapults you out of the seat.

By this time maybe 3 seconds have elapsed.

If you happen to still be conscious at this point (you may not be) fight the urge to pull the rip cord. If you open the 'chute at 40,000 feet you'll be a Popsicle by the time you get down to warmer air. The automatic opener on your parachute was armed when you came away from the seat. The parachute should open between 10-14 thousand feet on its own.

Your parachute pack contains a small oxygen bottle, activated by pulling a small "green apple". Now would be a very good time to do that. It contains just enough oxygen to let you free fall down to breathable air.



High altitude free fall technique

Remember your training on how to free fall? Good, you'll need it. Don't want to tumble or spin because you may tangle in the shroud lines when your 'chute deploys. You've got enough problems right now without having to add more.

Thwap! There's opening shock of the parachute! Your body is taking a serious beating today and there's more to come. But at least we're under a parachute, things are looking up. Time for our post ejection checklist.



I've always loved this one.

Canopy - check conditionVisor - up (assuming your helmet made it this far)Mask - discard

Seat kit - pull the handle that deploys the survival kit stored under your seat cushion (which is still attached to you). It will hang below you on a long strap and will hit the ground first. This is also when your life raft (if you have one) would deploy.

LPU - Inflate your Life Preserver Units or "water wings" if you're over water.

In water survival training mine didn't work. So just imagine me coming down in my parachute frantically blowing into the "manual inflation tube". I'm sure it looked as funny as it sounds.

Four line jettison - if you have a good parachute (no holes or tears) this opens up the back of the 'chute a little and gives you some steering and forward motion.

Prepare for landing - try to miss the trees, power lines, bull pastures and other hazards.



Another favorite

Assuming you make a good parachute landing you still may have to worry about being dragged behind the chute if the winds are high.

In training they dragged us behind a truck (ouch!) and a boat (glub!) to make sure we could disconnect from the parachute on land or water. I seem to recall drinking an awful lot of seawater before I got the chute cut loose.

So if you made it through all that, congratulations, you're now probably an inch shorter. That's how much the force of the ejection compressed your spine.

At least in my day the Air Force considered the probability of injury during an ejection to be 100%.



What's Next

The next step will probably be even smarter seats with vectored rocket nozzles that will "seek the vertical" no matter what attitude the aircraft is in. This technology is in development but I don't believe it's in production yet.

That's all for today. If you want to learn more I'll direct to the following site which has an almost obsessive level of detail about the subject (and some cool pictures).

Cool Site With Lots of Ejection Seat Info