Today I Learned…


Or, as they say on Twitter, “TIL.”

The Grumman EA-6B Prowler is a four place electronic warfare plane that specializes in jamming enemy radars and communications.

Like virtually all tactical jets, the crew rides on ejection seats.

 

In the video above, you’ll see all four seats fire at intervals of about half a second. If you look carefully, you see that they fire the back seats first, then the front seats. Additionally, the seats fire at a very slight angle outboard from the aircraft to generate separation between the seats. To cause the seats to angle outboard, the rocket motor is very slightly off centerline of the seat. Having the thrust line off centerline causes the angle of flight.

Here’s a picture of a test of the S-3B Viking, with a similar 4 seat ejection.

http://upload.wikimedia.org/wikipedia/commons/5/54/S-3A_escape_sys_China_Lake_NAN1-72jpg.jpg

What I learned today was that the firing handles of the various seats in the Prowler were color coded so the seat maintainers could ensure the proper seat was installed in the proper location in the cockpit.

  The GRUEA-7 Ejection Seats are simply superb—all I did was attach brass handles.  On the Prowler, the firing mechanisms on top of the ejection seats are color coded to help the aviators ensure that the correct seat has been installed.  The seats were painted the appropriate colors, (white for the left rear seat; orange for the right rear seat; purple for the right front seat; brown for the left front seat) and installed.

Sadly, in the video above, the pitching motion of the Prowler as it went off the bow caused the pilot’s seat to collide with another seat, killing the pilot. The three Electronic Countermeasures Officers (ECMOs) were recovered.

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8 Comments

Filed under navy, planes

8 responses to “Today I Learned…

  1. SFC Dunlap 173d RVN

    In my decades long career in parachutes I was pleased to learn that aerodynamic engineers refer to parachute systems as aerodynamic decelerators. Apropos I believe in that it specifically does not address it’s purpose for egress or intentional, dare I say, fun usage. The custom across the board is that if your life is saved by a parachute (auxiliary for intentional, emergency for egress), you owe the Rigger who packed it a fifth of their choice. I know sport parachutists and military (mostly) aviators are very, very good at making good on the tradition.

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    • captainned

      Fifth? Not that I’ll ever punch out of a plane but if I somehow become so stupid as to once again skydive and have to hit the reserve, it’s at least a full handle of the rigger’s choice.

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  2. captainned

    Cold cat. Probably a naval aviator’s greatest fear (SWAG). At least that shot went off the waist cat. Can’t imagine going off a bow cat and getting steamrolled by 100,000 tons of carrier doing 30 knots.

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  3. someoldguy

    Long ago I worked with a man who had been an engineer on the F-14 project. His specialty was ejection trajectory, ensuring that on ejection the crew would never come close to the canopy or the tail fins. I often wondered what he thought of the movie Top Gun..

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    • That scenario was based on a real world incident. The canopy did weird things in a flat spin.

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    • someoldguy

      As per my source, a tendency to flat spin with insufficient bank on a turn was one of the few faults of the Tomcat. In theory there was automatic correction for this but it was not foolproof. There was discussion of an elaborate anti-spin system that would deploy automatically but it was dropped. The simplest idea was just to deploy a braking chute but the jet exhaust was likely to burn through the line as the aircraft spun.

      The B-58 also had an automatic correction system that in theory would tone down the violence of certain maneuvers. The B-58 had a power-weight ratio and wing loading similar to the F-102, so much so that the TF-102A was used as a transition trainer. But a B-58 was much larger and heavier and trying to handle it like a fighter could lead to structural damage, such as empennage separation. :-o

      The B-58 had another problem – exploding early series J79 engines. The highly stressed engine just was not ready for frequent long flights of the SAC training variety. An anonymous survey revealed that most B-58 flight crews were afraid of their aircraft for these and other reasons. This was one of the numerous factors that led to the Hustler’s short service life.

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  4. Esli

    If I still built models, that would be a key detail. Never did paint one anything other than black and yellow stripes.

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  5. SFC Dunlap 173d RVN

    @captainned – you learned at some point it is so unfashionable to bounce without pulling all the handles…my sincere compliments & well done!!!

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