Wiggly lines on canopy
vy...@ico.com
embedded into the canopies on the Harriers and BA Hawks that I've seen. I
don't know what their purpose is but it looks more of a distraction to the
pilot from my point of view.
Brian Elliott
Explosive detonation cord to shatter the canopy before the ejector seat
(and pilot) pass through it.
brian
dave_sutton
sequence. You will also see them in the British Aerospace Hawk, Shorts Tucano, and others. Better than doing it with your head,
and faster and more reliable than canopy jettisoning systems.
"In god and Martin Baker we trust"
"Any fighter pilot who doesn't believe that he is
the best in the business is in the wrong business"
David Sutton, RED STAR AVIATION, pil...@planet.net
"Sales of Exotic Aircraft from Antonov to Zlin"
Martin Sagara
>
>These lines are embedded detonating cord (explosive) designed to fragment
the ca
>nopy at the beginning of the ejection
>sequence. You will also see them in the British Aerospace Hawk, Shorts
Tucano, a
>nd others. Better than doing it with your head,
>and faster and more reliable than canopy jettisoning systems.
Sometimes these lines are antennae for various radio-type equipment.
This seems to be true mostly for older aircraft such as the F-105B
Thunderchief and F-104C Startfighter.
Martin Sagara "Never before have so many,
Research Associate understood so little,
Wings Over The Rockies Air & Space Musuem about so much"
Hangar No. 1, Old Lowry AFB
Denver, CO James Burke speaking about
msa...@rmii.com technology in "Connections"
dave_sutton
Paul Jonathan Adam
> For some time I was wondering and want to know what those wiggly lines are
> embedded into the canopies on the Harriers and BA Hawks that I've seen. I
> don't know what their purpose is but it looks more of a distraction to the
> pilot from my point of view.
It's miniature detonating cord (MDC) bonded to the cockpit transparency.
The MDC is fired when you pull the handles to eject, and shatters the
cockpit (so you don't have to do it with your head on the way through).
Some alternatives are to jettison the canopy, or rely on canopy
breakers (steel spikes on top of the ejector seat). Canopy breakers leave
big chunks and can leave nasty sharp edges which might injure the pilot
on the way out: jettisoning the canopy takes a little time, and at the
RAF's definition of 'low' altitude you just won't have that time.
Hence, the use of MDC and those irritating lines across the canopy :)
--
"When you have shot and killed a man, you have defined your attitude towards
him. You have offered a definite answer to a definite problem. For better
or for worse, you have acted decisively.
In fact, the next move is up to him." <R.A. Lafferty>
Paul J. Adam pa...@jrwlynch.demon.co.uk
John Joseph Mercieca
>
> For some time I was wondering and want to know what those wiggly lines are
> embedded into the canopies on the Harriers and BA Hawks that I've seen. I
> don't know what their purpose is but it looks more of a distraction to the
> pilot from my point of view.
To the best of my knowledge the "wiggly lines" are embedded explosives
that tear apart the canopy when the pilot ejects.
Mike corby
clau...@pcohio.com> writes
>v >For some time I was wondering and want to know what those wiggly lines are
>v >embedded into the canopies on the Harriers and BA Hawks that I've seen. I
>v >don't know what their purpose is but it looks more of a distraction to the
>v >pilot from my point of view.
>
>if memory serves, these lines are embedded explosive charges to shatter
>the canopy should the pilot need to eject.
>
>-Mike
>
On the Canberra (if your memory goes back that far!), they were the VHF
antenna. The lid had explosive bolts around the circumference.
Regards, Mike
--
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Mike Corby FidoNet 2:252/27.0 BBS-The C.A.T.S. Board +44-1628 824852
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Tony Valle
> jettisoning the canopy takes a little time, and at the
> RAF's definition of 'low' altitude you just won't have that time.
It's not really time that is the issue, it's airspeed. In an aircraft like
the Harrier than can hover, there's no airflow to carry the canopy away
and in the event of an ejection during slow speed flight, the pilot would
be carried into the canopy with a high probability of injury.
--Killjoy
--
tva...@magicnet.net Finger for PGP Key
Sean Malloy
>v >For some time I was wondering and want to know what those wiggly lines are
>v >embedded into the canopies on the Harriers and BA Hawks that I've seen. I
>v >don't know what their purpose is but it looks more of a distraction to the
>v >pilot from my point of view.
>
>if memory serves, these lines are embedded explosive charges to shatter
>the canopy should the pilot need to eject.
More correctly, they're det cord that will be set off if the canopy
ejection fails. First you try to get rid of the entire canopy; if
you've taken enough damage that it doesn't happen, the det cord goes
off and fractures the canopy (or if you're in an attitude where the
canopy remains above the cockpit a la the flat spin in _Top Gun_; if
_that_ fails, there should be a canopy breaker on the upper back of
your ejection seat that will hit the canopy before your helmet does,
breaking the canopy that way.
During Vietnam, some F-4 Phantom II pilots had survival knives welded
to the ejection seat frame sticking up past the top of the seat
because the seat _didn't_ have a canopy breaker, and the pilot's head
stuck up past the top of the seat -- which caused several serious
injuries due to aircrew getting their helmets jammed down to their
shoulders when the canopies didn't separate during ejection.
--
Sean R. Malloy | American Non Sequitur
Naval Medical Center | Society
San Diego, CA 92134-5000 |
mal...@cris.com | "We may not make sense,
srma...@snd10.med.navy.mil | but we do like pizza"
Alistair Henderson
In article <498jsq$b...@adnetsol.adnetsol.com>, kko...@adnetsol.com (Ken Koller) writes:
|>Explosives to blow the canopy in the event of an ejection. As you may
|>know the cockpit on the harrier slides back, making it harder to blow
|>clear away so they just have the explosives to shatter the plexiglass.
Does this result in the crew getting showered with canopy fragments? And if so,
does it do them any harm, or is it not sharp enough to hurt them?
Al.
--
Al Henderson.
Computer Science III
Heriot-Watt University, Edinburgh
Email: cee...@cee.hw.ac.uk
RAF Web Pages: http://www.cee.hw.ac.uk/~ceeamh
Arnout Cosman
John Joseph Mercieca <mu...@keyworld.mt> wrote:
>vy...@ico.com wrote:
>>
>> For some time I was wondering and want to know what those wiggly lines are
>
>
>that tear apart the canopy when the pilot ejects.
I thought the "wiggly lines" were the antenna of some radio (VHF or UHF). I'm
sure I read it somewhere (in a book about the Harrier), but I haven't got the
book here right now.
The canopy should be blown away by primercord at the canopy frame. Not by
primercord in the plexiglass itself. The primercord ignites and the canopy is
blown away.
BTW according to Stephen Coonts (Flight of the Intruder) the ejection seat of
the A-6 Intruder is designed to blow _through_ the canopy, so maybe primercord
at the plexiglass itself is redundant.
S.B. Oltmans
(Yes, I'm a newbie, but that doesn't mean I don't know anything about planes,
just the Net)
dave_sutton
David S. Geldmacher
In a previous article, Pa...@jrwlynch.demon.co.uk (Paul Jonathan Adam) says:
>In article <vytas-23119...@vytas.ico.com> vy...@ico.com writes:
>> For some time I was wondering and want to know what those wiggly lines are
>> embedded into the canopies on the Harriers and BA Hawks that I've seen. I
>> don't know what their purpose is but it looks more of a distraction to the
>> pilot from my point of view.
>
>It's miniature detonating cord (MDC) bonded to the cockpit transparency.
>The MDC is fired when you pull the handles to eject, and shatters the
>cockpit (so you don't have to do it with your head on the way through).
For the current UK types mentioned, the posted information is correct
according to my references.
FWIW, however, not all wires embedded in canopies are det cord. The F-101B
had a VHF antenna embedded in the rear canopy. This was roughly
diamond-shaped when viewed from above, and did not have the distinctive
zig-zag pattern of MDC.
(More useless knowledge occupying otherwise valuable space in my brain).
Regards,
- David
David Bass
are indeed MDC (miniature detonating cord) as described by
Paul J. Adam in a previous post.
I think we can consider this pretty definitive in the case of the
(Sea) Harrier as my company have just completed delivery of a
cockpit mock up and manitenance trainer to the RN for the F/A-2.
Somebody else asked what the effect of having this stuff go off
just over your head would be. I am reminded of a tale involving
an ejection by a Harrier pilot. From my dodgy memory:
The pilot was attempting a STOL take-off when either the engine
refused to go to full power or the nozzles decided to not rotate.
He had enough thrust to be rolling forward at an uncomfortable rate
towards the edge of the field (Trees, ditch, hedge or something like
that). Oops, the brakes failed and the damn thing wasn't slowing
down quickly enough, so he decided to leave.
Unfortunately, he hadn't pulled his visor down (as apparently he was
required to do) and suffered some flash burns from the MDC.
Got himself into trouble over this one - not for dinking the
plane but for injuring his face.
Can't remember the provenance for this story, sorry.
BrianM4463
of the airplane is up.
<g>
BrianM4463
>>with canopy fragments?
Probably a little but hey, better than getting showered
with GROUND fragments, eh?
David S. Geldmacher
In a previous article, ric...@sails.demon.co.uk (Richard Sails) says:
>In article: <8177766...@fen168.demon.co.uk> d...@fen168.demon.co.uk
>(funkraum) writes:
[snip]
>> Internally heated automobile windshields have nearly inviisble
>> resistive wires embedded in the windshield sandwich, however I did
>> read somewhere that some aircraft windshields had a metal layer
>> deposited all the way across the sandwich.
>>
>> Truth or urban folklore ?
>>
>TRUE, (for some aircraft), a very thin metal layer, only just possible to
>see the differance between area's with metal layer in and those without!
>
>I don't think they use it for cars yet as its probably expensive.
I believe in the US, that the Ford Taurus/Mercury Sable is available
with a metallic gold layer in the windshield sandwich for electrical
defogging.
David
--
David S. Geldmacher, MD e-mail: ds...@po.CWRU.edu
Department of Neurology voice: 216-844-8203
Case Western Reserve University fax: 216-844-7239
Cleveland, Ohio 44106 USA
Richard Sails
> commented that the technology for internally heated windshields came
> from the world of aviation.
> Internally heated automobile windshields have nearly inviisble
> resistive wires embedded in the windshield sandwich, however I did
> read somewhere that some aircraft windshields had a metal layer
> deposited all the way across the sandwich.
>
> Truth or urban folklore ?
>
TRUE, (for some aircraft), a very thin metal layer, only just possible to
see the differance between area's with metal layer in and those without!
I don't think they use it for cars yet as its probably expensive.
--------------------------------------------------------------------
Richard Sails Personal EMail: ric...@sails.demon.co.uk
~~~~~~~~~~~~~ Work EMail:Richard....@warton.bae.eurokom.ie
Telephone (Home) UK: 01772 792039
Telephone (Work) UK: 01772 852866
This golden age of communications means everyone talks at once.
--------------------------------------------------------------------
I do not speak for my employer (other people are paid much more
money than me to do that!)
Joseph T. Galietto
>In article: <8177766...@fen168.demon.co.uk> d...@fen168.demon.co.uk
>(funkraum) writes:
>>
>> At the time of their introduction into automobiles, journalists
>> commented that the technology for internally heated windshields came
>> from the world of aviation.
>> Truth or urban folklore ?
>>
>TRUE, (for some aircraft), a very thin metal layer, only just possible to
>see the differance between area's with metal layer in and those without!
>
>I don't think they use it for cars yet as its probably expensive.
>
> --------------------------------------------------------------------
> Richard Sails Personal EMail: ric...@sails.demon.co.uk
Ford in the US marketed some high end cars with a "insta clear
windshield". This was produced by electro vapor depoistion on a layer
of the windshield sandwich. Very expensive part, I had a friend find
a flying stone with one. The replacement was >$1000 parts only.
Joe
rick...@phxonline.com
> During Vietnam, some F-4 Phantom II pilots had survival knives welded
> to the ejection seat frame sticking up past the top of the seat
> because the seat _didn't_ have a canopy breaker, and the pilot's head
> stuck up past the top of the seat -- which caused several serious
> injuries due to aircrew getting their helmets jammed down to their
> shoulders when the canopies didn't separate during ejection.
The F-4 had a canopy cutting knife attached to the inside of the canopy.
It was to be used to cut through the canopy if everything else failed. I
don't know if anybody ever used it. It would take a long long time to
cut through the sucker. It probably would be useless if you really needed
to get out and the canopy didn't come off.
It is not possible in the F-4 to hit your head on the canopy when the
ejection seat fires because the seat will not fire unless the canopy is
gone. There is a safety pin installed in the seat that physically prevents
the seat from firing until the pin is removed. This particular safety pin
is attached to a steel cable that is attached to the canopy. When the seat
is fired, two thrusters on the bulkhead push the canopy up into the
windstream, which causes the canopy to be ripped from the airplane.
When the canopy goes, it pulls the safety pin from the banana links so
that the rocket moter can fire and eject the seat from the airplane.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Rick Keyt, Sysop | Phoenix Online
rick...@phxonline.com \__[O]__/ | Phantoms
602-678-5776 (BBS) \__[O]__/ Forever
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Doug Brindle
The EA-6B has a very thin layer of gold sandwiched in the canopy 'glass'.
Without this layer of gold, the Prowler would "Jam" itself with
EMI energy and every pilot/crew member would be sterile for life after
one flight!
-Doug