The Ejection Site

The Ejection Seats of the F-104

The F-104 ejection seat story is a classic story of the evolution of egress systems over the service life of an aircraft. In those days, the USAF would specify to the aircraft manufacturers (e.g. Lockheed) the requirements of the aircraft subsystems. In the case of the egress system these specifications would include such items as minimum/maximum altitude and minimum/maximum airspeed envelope. In the early days of the XF-104 program, it was decided due to the limitations of the available ejection seat catapults, the ejection seat should fire downwards. This allowed for the best capability of clearing aircraft structure, including the vertical fin at higher speeds. It also effected the windblast on the pilot.

Later the seats were replaced with an upward firing seat, once capable catapults were available. These seats served well in USAF service, but were still not considered suitable for extreme low level ejections with high sink rates. This was a particular problem to the German Luftwaffe, which used the F-104G as a low level attack plane. They initiated programs to have the seats upgraded, and eventually decided to have the seats replaced with a seat of Martin-Baker design.

Stanley B

Although the aircraft manufacturer was tasked with seat development, it was often sub-contracted to other companies that were more experienced in the industry. In the case of the F-104, Lockheed turned to Stanley Aviation Corp. for the development of the seat.

This seat was fitted to the early prototypes and the first twenty-six F-104A aircraft. This version of the seat did not have any retract mechanisms for the pilot's legs or arms, merely a set of foot guards that the pilot had to manually place his feet into prior to ejection. This seat was used successfully at altitude. For a personal story of one man's ejection, click here. It included in its features a leg restraint system based on a set of ankle clamps. Firing the seat involved first pulling the legs back so that the feet and ankles would arm the clamps which were then actuated as part of the pre-ejection sequence started by pulling the triangular shaped ring on the front of the seat pan. This sequence used a ballistic thruster under the seat to rotate the thigh guards up to the front position, tighten the pelvic restraint straps, close the ankle clamps by releasing a pin restraining them, lock the inertia reel. Additionally, the aircraft control stick is unlocked and pulled forward out of the pilot's ejection path by means of a spring mechanism, while the cabin pressure is dumped by a valve on the cockpit bulkhead. On firing the catapult, the seat began to move downward and mechanically unlocked the escape hatch under the seat forcing it into the windstream for removal.

As the leg guards reach the fully deployed position, the right side one fires a M3 initiator to fire the catapult.

If the catapult failed to fire, the seat could be released with the aid of gravity by manually jettisoning the hatch cover, which would prepare the seat for gravity release. A further pull on the ejection handle would release the upper catapult attach point, allowing the seat to fall free of the aircraft.

Stanley C

The 'C' seat was a improved version of the 'B' seat, installed in the next fifteen aircraft of the F-104A production line. The primary improvement was the addition of a set of stirrups worn on the pilot's boots which were clipped into a set of cables on reels located under the seat pan. This eliminated the requirement that the pilot manually retract his feet before pulling the seat handle. The reels were actuated by the pre-ejection thruster to pull the airman's feet back to the base of the seat pan. These cables are severed at the same time as the lap belt is released by means of two pairs of cartridge fired cutters. Other manufacturing and design improvements primarily changed the appearance of the seat with little mechanical changes.

As with the 'B' seat, while traveling down the rails a trip bar actuates a M-4 two second delay initiator which then opens the seat belt and releases the pilot's harness. A lanyard attached to the seat belt arms the parachute aneroid release system which deploys the parachute when the proper altitude is reached.

Stanley C-1

Stanley seat details
Photos of a F-104 C1

Stanley then developed the C-1 ejection seat. This seat used the M-4 downward catapult which was available off the shelf. The seat had many advanced features for the time period, including foot restraints, single action activation, arm restraints and leg guards. Many of the contemporary seats had a system where raising a guard would jettison the canopy or hatch, then the separate trigger would be actuated by the pilot to fire the seat. In the C-1, both the canopy jettison and seat firing were actuated by a single pull on the central ejection seat handle. This activated a series of events where the hatch would be jettisoned, the leg guards would swivel forward to keep the thighs from spreading in the wind blast as well at to deploy the arm retraint netting, The retract reels would reel in the foot stirrups, the inertia reel would be locked, and the catapult would fire to eject the pilot. After ejection, the sequence would continue after a pyrotechnic pause to sever the foot stirrup lines, release the intertia reel shoulder harness, rotate the automatic lap belt to the unlock position.

The seat structure is based on a pair of angle iron like beams with a sheet metal headrest box. The seat bucket is firmly attached to the beams. Seat height actuation is achievied by movement of the whole assembly on the cockpit rails. The along side the seat bucket and hinged at the lower front are the leg guards. Attached to the upper ends of the stowed leg guards is the arm restraint netting. The net is a rough triangle of webbing which is also attached to the seat bucket behind the parachute area. The net is stowed in a pair of 'wings' on the sides of the seat bucket back. The foot restraint 'boxes' were made of formed sheet metal and firmly fixed to the seat bucket. The seat fits into the cockpit via a set of rollers on the outer edge of the seat beams which interface with the cockpit rails.

One interesting feature of the Lockheed ejection seats was the inclusion of a set of stirrups that the pilot would don prior to entering the cockpit. The stirrups were attached to the seat by means of a pair of retractors on the base of the seat pan in the foot rest area. These retractors had a length of cable in them and a spring tension reel to retract them. In normal use, the pilot would have a light tension on his heels as he had them on the rudder pedals. In case of an ejection, ballistic gas would cause the take up reels to retract the crewman's feet back into the foot rests and hold them there until seat separation. At seat separation, the retract cables are severed by two separate systems to make sure that the crewman is freed from the seat. This system served two functions- first it kept the crewman's feet from contacting any portion of the cockpit or canopy during ejection, second it helped prevent flail type injuries of the crewman's legs in the windblast. Alongside the headrest on the right is a handle used for manually activating one of the severing systems. This could be used to assist in removing an injured crewman, or for the crewman to rapidly egress the aircraft on the ground.

Overall, the less than 100 C-1 seats manufactured performed similarly to other seats of the vintage in terms of saves. The USAF wanted better performance in the low altitude arena, such as during takeoff and landing. While the development cycle of the XF-104 to the early F-104A was proceding, other development efforts had produced a catapult that was more suitable to upward ejection seats. These two factors led Lockheed to produce a new upward firing version of the seat. Due to the changes, the new seat was given a new designation: the Lockheed C-2.

Lockheed C-2*

Lockheed C-2 seat details
Lockheed C-2 seat photos

Visually, the C-2 was very similar to the C-1, with a few notable differences. The foot rests were changed to remove the sides, and hinged to the bottom front edge of the seat bucket. The other visual difference from the front of the seat is the shape of the ejection pull handle, which was triangular on the C-1 where the early C-2 used a slightly extended triangle with more of a rectangle base. The headrest was beefed up a little and a canopy breaker was attached to it. These features allowed for the foot retracts to work more reliably, the handle to be grabbed easier, and if the canopy failed to jettison, to eject through the glass. The other major change was of course to the XM10 rocket catapult for upward ejection. Later seats incorporated a rotary actuator to facilitate seat separation. The rotary actuator is a simple device that under gas pressure rotates rapidly to reel in an inverted 'Y' shaped strap from the single end. The strap is routed behind the parachute, and then under the rigid seat survival kit to the front lip of the seat bucket. This retract action causes the strap to be pulled tight, and forces the seat kit, parachute and occupant away from the seat structure to insure positive seat separation.

The rocket catapults are two tube models with an internal catapult. The catapult balistically pushes the seat up the rails and as the tube nears the end of the catapult stroke, the internal rocket ignites. The rocket nozzles are unmasked as the tubes separate and the rocket efflux is directed aft and downwards such that the thrust is upwards and forward thru the nominal center of gravity of the seat/man package. In a perfect allignment configuration, this would generate a stable lift to maximum trajectory. In the real world where the factors effecting this include- the mass of the occupant, the slump of the occupant under g-forces, the movement of the occupant due either to aerodynamic forces or voluntary/involuntary reactions, and the aerodynamic drag effecting equipment on the crewman- the seat would tend to tumble. This tumbling was considered benificial as it would promote clean seat-man separation. In rare situations, this separation was not far enough as described by Chuck Yeager Brig. Gen. USAF Ret. in his autobiography 'Yeager'. In his ejection from the NF-104A, the aircraft was in a flat spin, and the seat/man package began its separation with the man portion facing downwards after a pitch downwards. After separation, Yeager was struck by the seat which had a lower coeficient of drag compared to Yeager in his pressure suit and thus fell faster than him. The rocket motor struck his helmet, which was being fed oxygen from the seat survival kit and broke it open. Rocket slag ignited the suit and the flames were fed by the oxygen. Yeager managed to open the visor and shut off the flow of oxygen, but his face and hands were burned.

The ejection seat pull ring was also changed to a 'D' shape (flat side down). This was done to give better grip from the pilot's hands and it would reduce the tendency to pull to one side if only one hand was used to initiate ejection. The automatic lap belt was also changed to a newer model. The parachute (BA-18 and -22) system of the C-2 included a lanyard activated timer mechanism to give some time for the seat to be clear prior to parachute deployment. For low altitude such as takeoff and landing, a zero delay lanyard was attached by the crewman. This would allow for more rapid deployment of the parachute at low altitudes.

As time went on, the seat evolution continued with the addition of a newer catapult, the XM10E1. These changes were to give the seat greater vertical height, and a more stable launch. Other rocket catapults were also tested, with the final choice being designated as the M-10 rocket catapult.

As usual in engineering design, any failures of the seat systems, irrelevent of their effect on the success rate, were investigated to determine if configuration changes were required. One item that was true of many seats of the day was lack of stability in high speed ejections. A related problem was seat separation and parachute deployment occuring at too great a speed. In order to address these problems some significant changes were made.

Lockheed S/R-2

Lockheed S/R-2 seat details

The new variant was utilized only on some versions of the F-104, hence to keep it clear which version was which the new version was named the Stabilization/Retardation-2 (S/R-2 or SR-2). The S/R-2 was equipped with a fast deploying drogue chute which kept the seat from tumbling and helped decellerate the seat/man package to a speed where the parachute deployment forces were more within the range of human tolerance. Another change that occurred over time was the change to a gas operated retractor for the shoulder harness to position the occupant prior to the catapult stroke. The concept was to set the occupants back against the seat structure and hopefully straighten his spinal column before the G load increased. The canopy jettison system was also modified in concert with the delay charges to provide a faster egress from the aircraft. One other point to mention in regard to the S/R-2 is that the emergency oxygen system was optimized for high altitude use.

In order to reduce parachute opening times for low altitude ejections, a gun deployed parachute made by Weber was incorporated. The chute includes an integral drogue gun which fires a slug out at a 45 degree angle over the crewman's left shoulder. This parachute was also installed on some of the C-2 seats, so the presence of the gun deployed parachute alone does not indicate the seat is an S/R-2. The parachute firing mechanism was activated during seat seperation and included an aneroid system to prevent the chute from deploying above 15000 feet.

Martin-Baker Mk. Q7(A)

Martin-Baker GQ-7(A) front and details
Martin-Baker GQ-7(A) back and details
Photos of the GQ-7A seat
Photos of a different GQ-7A seat
GQ-7A display at Deutches Museum
In German and other European service, the F-104 was modified for multi-role capability which added much weight to the airframe and thus increased the wing loading. This led to very rapid descent rates in case of an engine failure and would require rapid ejection, especially at low altitude. While the C-2 was rated at 120kts at zero altitude, the seat was not as effective in high sink rate situations. This led to an unacceptable level of failures of the seat in German service. As other German aircraft were equipped with Martin-Baker seats, and did not have the same failure rate (which was in part due to the fact that the F-104 was being asked to perform in a role it had not been intended to), The Luftwaffe had a few aircraft equipped with a special version of the Mk. 7 seat. The F-104 version was known as the Martin-Baker Mk. GQ-7(A). This seat has 0-0 capability and was based on lots of experience Martin-Baker had with many different aircraft at the time. The GQ-7(A) does have some differences from other Mk. 7 seats. The major visible difference is in the parachute pack, which is a hard fiberglass shell and makes up the back rest of the seat. Due to the retrofit assembly, which bolts in between the existing rails of the cockpit, the seat distance from the back to the front had to be minimized. This led to a unique pack which wraps backward around the sides of the rails. Thus, the GQ-7(A) has a rather flat fronted appearance when compared to a seat like the Mk. H-7 seats used in the F-4 Phantom.

Note: Interestingly, even though the seat and its dirivitives were designed by Stanley, production was licensed at some point to Lockheed, and thus it is generally refered to in most references as 'the Lockheed seat'. Even pilots who have used these seats call them Lockheed seats.

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