Widebody? Tracking - was: checking chest straps

Widebody? Tracking - was: checking chest straps

Post by Skratch Garriso » Mon, 12 Feb 2001 07:13:53



Quote:
>Hey Skratch....I saw a book at an aerodrome some years ago - Are you that
>guy who invented the widebody tracking style?

Maybe ..

As I understand it people like Spud Manning knew about
a swan dive / delta position clear back in the late 1920's.

That knowledge seems to have been swept aside by World War II.

Somewhere in the mid 1950's a French guy, whose name ought to
be more well known, invented the French Cross, which is just
what it sounds like - arms and legs spread eagled with an arch
at the waist.

Voila!  Stable freefall!

Apparently other people before that had noticed periods of not
tumbling when, for example, they were relaxed on their back in
the rocking chair position.

Jack Pryor, the guy who put me out on my first jumps, started
jumping in 1953 by buying a military surplus seat pack and going
up and jumping out.

When he wanted to pull he would tuck and tumble, timing the
sequence of blue/green/blue/green/... so that the seat pack
would be up on top while the chute was coming out.

He learned about stable freefall when he ran into somebody
(at an airshow?  in 1957?) who told him about the French Cross
(and probably the French Frog, which was an advanced position
where you could start in a French Cross and then bend your
knees and elbows and be a little more relaxed about the whole
thing).

I know when I started in 1962 getting stable was still a topic
of conversation.

In the late 1950's Loy Brydon, who helped start the Army Team
and did a lot of early pioneering, got the idea of tracking
in freefall while watching some ski jumpers.

        (My first impression of Loy Brydon was in 1964 at the
        (Professional Meet in Las Vegas. The Army Team used to
        (take a no contact 4 way diamond with smoke on each guy
        (and kind of track it in over the crowd and then do a
        (bomb burst breakup and pull.
        (
        (Apparently the day before they hadn't exactly pulled
        (up at 2,000 ft and the meet director, Norm Heaton,
        (had had some words with them.
        (
        (It was the wrong approach.
        (
        (So here I am the next day, a raw college student who
        (has never seen anything like this before, and here
        (they come. The plane is at 13,000 ft which is practically
        (in low Earth orbit, and suddenly there's the smoke!
        (
        (They fall for a long time and then the smoke starts
        (angling across the sky! Holy shit, they're moving!
        (
        (They keep coming, they're straight up, they're at
        (opening altitude, they're still coming. It's beautiful!
        (It's terrifying! My God! I've never seen anybody in
        (freefall this close! I can read their name tags!
        (
        (The sound of their freefall is overwhelming.
        (
        (They break. The lead guy (Loy Brydon) does a 180
        (and goes underneath, the tail goes over the top,
        (the two wings turn inward and cross shoulder to
        (shoulder.
        (
        (The low man lands 20 seconds later. The high man
        (was in the saddle for 27 seconds.
        (
        (I join the circle of onlookers as they daisy chain
        (their lines and gather up their canopies, eavesdropping
        (intently on their casual commentary.
        (
        (Their leader is this gruff looking sargeant.
        (He's built like a Sherman tank and looks twice as tough.
        (
        (I am thoroughly impressed.
        (
        (I am convinced he could pull at 100 ft, hit the ground,
        (and get up and run the extra distance needed for an
        (opening shock.

In 1965-66 I did a lot of tracking jumps trying different body
positions, arms and legs wide, arms and legs in close, lots of
reverse arch, flat, arms high like superman.

Later when jump suits started happening I tried lots of positions
trying to make use of the extra wing and other jumpsuit fabric.

I also drove around Elsinore measuring distances trying to figure
out how far we were actually going.

When I got a piggyback in 1968 I did another round of this,
because the flat front really changed things, and pretty much
settled on small variations of the original track that Loy Brydon
had come up with.

The basic idea is to present maximum area to the wind, shaped
so as to deflect as much as possible backward and cover the
maximum horizontal distance.

I am pretty sure from watching pictures of people jumping smoke
that we don't get smooth, laminer flow over the top like an
airplane wing. Our wing span from shoulder to shoulder is too
small and our angle of attack is too high.

The one small improvement that I came up with happened one day
when I was thinking about this maximum air scooping idea. I put
my jumpsuit and gear on and looked in full length mirror and
noticed that if I turn my palms up my arms/elbows/shoulders
can make a better scoop.

If that's what you mean by "wide body tracking" then yes,
I did that.

The one improvement on that that I have heard of is turning
your toes outward to make use of the bootie and inner thigh
surface area. I haven't gotten around to getting booties yet
but it makes sense to me. Give it a try.

Another interesting question is why people seem to start
their track at a steeper angle and then flatten out.

I believe that is an illusion.

If you think about after you've been tracking for a while
and you're in a steady state, you are at a certain angle
relative to the wind and a certain angle relative to the
ground.

When you first start, the wind is coming straight up, so in
order to get the best angle relative to the wind you have
to get a steeper angle relative to the ground, but after while
the wind is coming from more out in front, so you can flatten
out relative to the ground, but you're actually at the same
angle relative to the wind the whole time.

---

I think tracking is not only really useful but is great
for recreational use and I'm glad it is now socially
acceptable to go up and track as a group for the whole jump.

I posted something about that a few years ago.
You can see it at
http://indra.net/~bdaniels/ftw/
down towards the bottom of the page.

I really need to get back to that web site and add some
jump stories. That's what it was for in the first place.

Skratch

Australian SCR-49   (I think .. It's been over 30 years :-)

--

http://indra.net/~bdaniels/

 
 
 

Widebody? Tracking - was: checking chest straps

Post by Colin Fitzmauric » Mon, 12 Feb 2001 07:21:44

As always Skratch

Colin Fitzmaurice       http://www.theparachutecentre.com
The Parachute Centre
Tilstock Airfield
Whitchurch
Shropshire SY13 2HA
United Kingdom
+44 (0)1948 841111