I'm trying to find out what manual controls are on the Martin-Baker Mk.4 ejection seat and there's a black and yellow spherical knob by the pilot's right knee that has escaped my researches. I know it isn't the inertia reel control or the manual override handle and the PEC is usually a green box off to the side.

Any ideas?

MB Mk.4

MB Mk.4 detail

Pictures courtesy of Carlos Menendez San Juan

  • $\begingroup$ Can you label the ones you do know? I would have said the one you're asking about is the manual override. $\endgroup$ Commented Mar 1 at 3:08
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    $\begingroup$ @OrganicMarble None of the items I mentioned are visible in that photo. The 'manual override handle' I was refering to is to separate the pilot from the seat without firing the ejection system (ejectionsite.com/emb2gen.htm) . I looked at the document that Party_Ark linked to, and it's called the 'manual separation handle' there. $\endgroup$ Commented Mar 1 at 10:31
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    $\begingroup$ It is clearly a manual gearstick to control a manual transmission; also indicates this is a left-hand-drive aircraft. (humour) $\endgroup$
    – Criggie
    Commented Mar 2 at 20:40

1 Answer 1


It is the Emergency Oxygen Manual Operating Handle

enter image description here

The emergency oxygen system has a gaseous oxygen storage bottle fitted to the back of the ejections seat which feeds its supply through an emergency oxygen demand regulator to the rear of the seat portion of the PEC [Personal Equipment Connector] and thence into the oxygen mask tube. Emergency oxygen is selected manually by pulling the emergency oxygen knob, or automatically on ejection as the seat rides up the rails. When the pilot separates from the seat after ejection, the separation of the man and seat portions of the PEC breaks the emergency oxygen supply and allows air to be breathed at ambient pressure.

source - English Electric Lightning F Mk 36 & T Mk 5 Flight Manual

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    $\begingroup$ Excellent answer! That document is perfect! $\endgroup$ Commented Mar 1 at 10:32

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