writer needs help

Okay ... you all asked for it and I appreciate your help so much!! I'll
just give you what I have so far, and you can tell me if it's right.
How's that?

1- Regarding 100LL. I gather from your replies that it evaporates very
quickly. But I'm talking about a major flood of it in an enclosed area
with only moderate ventilation in just below freezing temperatures. I
have no idea how long it would take to evaporate and the whole segment
depends heavily on this.

2- A person exposed to this fuel, i.e., skin, eyes, fumes ... off and
on for 24 hours, would end up with hydrocarbon poisoning as a result of
transdermal absorption, burned eyes, and some nasty chemical burns
which eventually will fade away with new skin growth. (I do give this
poor individual a break ... it's raining and that dilutes it a bit.)

3- Regarding the ELT. While surfing the internet, not only didn't I
find the answer to this one, it only netted me more questions. This
pilot has a Piper Malibu airplane (the name is not specified in the
story because I'm really not interested in getting sued, but that's the
model I'm using). The ELT can be off, on, or armed. Here's what I
need to accomplish ... That airplane cannot be found before 24 hours or
it'll mess up the rest of the book. The Civil Air Patrol told me that,
when they go looking for a missing airplane, the only thing an ELT does
is locate the "general area" which could be 20-30 square miles. They
still have to set up a grid and comb the whole area with air and ground
crews ... it doesn't tell them exactly where an airplane is. Is that
right?

4- What position does the ELT have to be at in flight, for it to go off
by itself when it needs to?

5- Here are the extra questions that came up when I was looking for the
answer to the previous one. I found a .wav file of what an ELT sounds
like when it goes off. Is that an audible noise? How long does it
last? That would drive my pilot batty if it goes on very long.

No doubt I'll have a few other questions depending on the answers to
these, but it's sure nice of you to help.

--Wendy


--
wendy
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

The ELT can be off, on, or armed. Here's what I
need to accomplish ... That airplane cannot be found before 24 hours or
it'll mess up the rest of the book. The Civil Air Patrol told me that,
when they go looking for a missing airplane, the only thing an ELT does
is locate the "general area" which could be 20-30 square miles. They
still have to set up a grid and comb the whole area with air and ground
crews ... it doesn't tell them exactly where an airplane is. Is that
right?

It is my understanding that this is true. I have not done CAP searches
so my knowledge of this is not first hand. The ELT (at least the older
models which transmit on 121.5) are just radio beacons. In theory one
can just use a directional antenna and sweep it around to find the
source of the signal, but this is complicated by terrain and
reflections, and the fact that directional antennas are not all that
directional.

The airplane could have crashed (I presume it crashes) in a compromising
position which makes the signal even harder to zoom in on. Passing
aircraft who are monitoring 121.5 can pick up the signal and relay to
ground control that there is an ELT in the area. I've heard several
myself. (Often they turn out to be in parked airplanes, perhaps after a
hard landing.) After 9-11 pilots are required to monitor 121.5 in
flight if practical (it's used for intercepts).

I'd trust what the CAP says. They do it all the time.

4- What position does the ELT have to be at in flight, for it to go off
by itself when it needs to?

Armed. This is the standard position.

I found a .wav file of what an ELT sounds
like when it goes off. Is that an audible noise?

No. It is a radio transmission; you can hear it on the aviation bands
on 121.5. Pilots should listen briefly before parking on 121.5 to
ensure that their own ELT hasn't gone off.

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

Wendy,


1- Regarding 100LL. I gather from your replies that it evaporates very
quickly. But I'm talking about a major flood of it in an enclosed area
with only moderate ventilation in just below freezing temperatures. I
have no idea how long it would take to evaporate and the whole segment
depends heavily on this.

Well, you don't tell much about the scenario (which is perfectly ok), but I
could imagine some problems with it: First, if the "flood" is coming from the
crashed plane, please keep in mind that, especially after some period of
flight, there might not be enough fuel aboard for a flood. Consider the fuel
carrying capacity of the Mailbu, the duration of flight and the hourly
consumption. Also, after a crash, I find it hard to imagine that there will be
an area enclosed enough for the fuel to not simply drain away into the ground -
but again I don't know enough about the scenario. Below freezing would
certainly decrease evaporation, but it would also make it very hard for your
character to survive for 24 hours, fuel vapors not withstanding. If he/she
comes in direct contact with fuel, the cold from the evaporating fuel would add
to that, so the other effects you mention might not be his/her primary problem.
Also, rain at just below freezing sounds kind of unlikely.

3- Regarding the ELT. While surfing the internet, not only didn't I
find the answer to this one, it only netted me more questions. This
pilot has a Piper Malibu airplane (the name is not specified in the
story because I'm really not interested in getting sued, but that's the
model I'm using). The ELT can be off, on, or armed. Here's what I
need to accomplish ... That airplane cannot be found before 24 hours or
it'll mess up the rest of the book. The Civil Air Patrol told me that,
when they go looking for a missing airplane, the only thing an ELT does
is locate the "general area" which could be 20-30 square miles. They
still have to set up a grid and comb the whole area with air and ground
crews ... it doesn't tell them exactly where an airplane is. Is that
right?

Well, CAP certainly know how to do it right. It would have to be difficult
terrain, I guess, to not find the ELT in 24 hours. Also, it would not be
uncommon for the ELT to not work or to run out of battery power before 24 hours
are over.


4- What position does the ELT have to be at in flight, for it to go off
by itself when it needs to?

Armed. You can also manually put it to on after the crash if the automatic
function didn't work.


5- Here are the extra questions that came up when I was looking for the
answer to the previous one. I found a .wav file of what an ELT sounds
like when it goes off. Is that an audible noise? How long does it
last? That would drive my pilot batty if it goes on very long.

That noise is audible only in a radio tuned to 121.5 MHz (or 243 MHz, the
military emergency frequency). This radio signal emitted by the ELT is used by
rescue workers to find the ELT.


--
Thomas Borchert (EDDH)

"Jose" wrote in message
.. .
[...]
I'd trust what the CAP says. They do it all the time.

I think it's possible that the answer from the CAP has as much to do with
how many search airplanes they can equip with direction-finding equipment as
it does with what's possible with an ELT.

Assuming the battery in the ELT remains charged enough to run the ELT, the
ELT signal is sufficient to *eventually* pinpoint the airplane. Caveats
include (may not be limited to ) that: the initial contact is often by
satellite, and on the 121.5 frequency it can take several passes before the
satellite has a fix that's even good enough to start a search; newer ELTs
using the 406 Mhz frequency can be more easily pinpointed by satellite; some
ELTs even have a link to a GPS and encode the airplane's coordinates in the
transmission. Of course, that's all in addition to the comment Jose already
made.

The new GPS-connected ELTs can allow the search to be completed VERY
quickly. Once someone receives the signal, it's as simple as "go to
these coordinates" (assuming the crash site is reasonable visible...one can
imagine unusual situations in which it's not readily apparent someone
crashed there, but even then, if you've got GPS coordinates, you still go
check and you SHOULD find something).

There have been interesting threads in this newsgroup in the past regarding
ELTs and search methods. Using Google to search for keywords like "ELT",
"satellite", and "search" will probably turn up those threads.

4- What position does the ELT have to be at in flight, for it to go off
by itself when it needs to?

Armed. This is the standard position.

And note that "On" is the setting to manually activate the ELT.

Pete

wendy wrote:

1- Regarding 100LL. I gather from your replies that it evaporates very
quickly. But I'm talking about a major flood of it in an enclosed area
with only moderate ventilation in just below freezing temperatures. I
have no idea how long it would take to evaporate and the whole segment
depends heavily on this.

There is little difference in 100LL than regular car gas. The only
difference is the presence of a lot of lead to raise the octane, blue
dye rather that the orangish stuff most car gas has, and some anti-gum.

You can do an experimentation or research on gasoline and apply it to
100LL.

3- Regarding the ELT. While surfing the internet, not only didn't I
find the answer to this one, it only netted me more questions. This
pilot has a Piper Malibu airplane (the name is not specified in the
story because I'm really not interested in getting sued, but that's the
model I'm using). The ELT can be off, on, or armed. Here's what I
need to accomplish ... That airplane cannot be found before 24 hours or
it'll mess up the rest of the book. The Civil Air Patrol told me that,
when they go looking for a missing airplane, the only thing an ELT does
is locate the "general area" which could be 20-30 square miles. They
still have to set up a grid and comb the whole area with air and ground
crews ... it doesn't tell them exactly where an airplane is. Is that
right?

Pretty much. There are multiple flavors of ELT, but the one most
aircraft has is pretty lousy. False activiations and failure to
activate are common. These old ELT's take two satellite passes
to get any indication and even those position reports are pretty coarse.
In fact, the support for satellite detection of these old elt's is
scheduled to be pulled in 2009.


4- What position does the ELT have to be at in flight, for it to go off
by itself when it needs to?

It's supposed to be set in the ARM position which means the G switch
will turn it on in the event of a crash. This is the way it is left
all the time. Many older units don't even have an easy way for the
pilots to access this.


5- Here are the extra questions that came up when I was looking for the
answer to the previous one. I found a .wav file of what an ELT sounds
like when it goes off. Is that an audible noise? How long does it
last? That would drive my pilot batty if it goes on very long.

That's what the radio transmission sounds like when it is activated.
You can't hear that in the plane (unless you're tuned to 121.5 on the
readios).

Ron Natalie wrote:

There is little difference in 100LL than regular car gas. The only
difference is the presence of a lot of lead to raise the octane, blue
dye rather that the orangish stuff most car gas has, and some anti-gum.

You can do an experimentation or research on gasoline and apply it to
100LL.

Ron,
In some cases, automobile gasoline can evaporate faster than avgas

"Avgas vapor pressure remains
constant at a 6.5-psi level regardless of
the time of year or area of the country it
is used. Autogas vapor pressure is often
changed in some parts of the country
from a high of 15 psi to a low of 7 psi.
(California regulations define a
maximum of 7 psi.)"

http://www.eaa.org/education/fuel/autogas_vs_avgas.pdf

Hai Longworth

wendy wrote:
Okay ... you all asked for it and I appreciate your help so much!! I'll
just give you what I have so far, and you can tell me if it's right.
How's that?

1- Regarding 100LL. I gather from your replies that it evaporates very
quickly. But I'm talking about a major flood of it in an enclosed area
with only moderate ventilation in just below freezing temperatures. I
have no idea how long it would take to evaporate and the whole segment
depends heavily on this.

2- A person exposed to this fuel, i.e., skin, eyes, fumes ... off and
on for 24 hours, would end up with hydrocarbon poisoning as a result of
transdermal absorption, burned eyes, and some nasty chemical burns
which eventually will fade away with new skin growth. (I do give this
poor individual a break ... it's raining and that dilutes it a bit.)

3- Regarding the ELT. While surfing the internet, not only didn't I
find the answer to this one, it only netted me more questions. This
pilot has a Piper Malibu airplane (the name is not specified in the
story because I'm really not interested in getting sued, but that's the
model I'm using). The ELT can be off, on, or armed. Here's what I
need to accomplish ... That airplane cannot be found before 24 hours or
it'll mess up the rest of the book. The Civil Air Patrol told me that,
when they go looking for a missing airplane, the only thing an ELT does
is locate the "general area" which could be 20-30 square miles. They
still have to set up a grid and comb the whole area with air and ground
crews ... it doesn't tell them exactly where an airplane is. Is that
right?

4- What position does the ELT have to be at in flight, for it to go off
by itself when it needs to?

5- Here are the extra questions that came up when I was looking for the
answer to the previous one. I found a .wav file of what an ELT sounds
like when it goes off. Is that an audible noise? How long does it
last? That would drive my pilot batty if it goes on very long.

No doubt I'll have a few other questions depending on the answers to
these, but it's sure nice of you to help.

--Wendy


--
wendy
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -


Here are a couple of links that describe an interesting true story
related to your question:

http://planeandpilotmag.com/content/..._haystack.html
http://www.ntsb.gov/ntsb/brief2.asp?...FA061& akey=1

Thanks for asking, by the way. The pilots here all get pretty worked
up over the steady stream of aviation-related inaccuracies and
misrepresentations in the media. Just for the record, when an airplane
"stalls", it doesn't mean the engine died as with a car. It means
something else. And when the engine does die, airplanes still are able
to glide to a safe landing, they don't just fall out of the sky.

-R

OK not to hijack this thread, but what you and Peter are saying about ELT's
has me confused. I assume the OP is talking about the standard,
been-around-for-twenty-years, 121.5 MHz ELT. How in the world would a
satellite orbiting thousands of miles above the earth pick up this signal,
let along get a fix on it? This is something I have never heard of.

"Ron Natalie" wrote in message
m...
wendy wrote:

Pretty much. There are multiple flavors of ELT, but the one most
aircraft has is pretty lousy. False activiations and failure to
activate are common. These old ELT's take two satellite passes
to get any indication and even those position reports are pretty coarse.
In fact, the support for satellite detection of these old elt's is
scheduled to be pulled in 2009.

I assume the OP is talking about the standard,
been-around-for-twenty-years, 121.5 MHz ELT. How in the world would a
satellite orbiting thousands of miles above the earth pick up this signal,
let along get a fix on it? This is something I have never heard of.

Not by accident. There are satellites that are designed to (in part)
look for such signals. I don't think those satellites are thousands of
miles above the earth, only a few hundred miles is needed to get into
space. In any case, their receivers are =very= good, and there isn't
anything in the way to block the signal. You'd be surprised how far
signals (including ordinary acoustic signals like conversation) carry
under ideal conditions.

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

Jose wrote:
I assume the OP is talking about the standard,
been-around-for-twenty-years, 121.5 MHz ELT. How in the world would a
satellite orbiting thousands of miles above the earth pick up this
signal,
let along get a fix on it? This is something I have never heard of.


Not by accident. There are satellites that are designed to (in part)
look for such signals. I don't think those satellites are thousands of
miles above the earth, only a few hundred miles is needed to get into
space. In any case, their receivers are =very= good, and there isn't
anything in the way to block the signal. You'd be surprised how far
signals (including ordinary acoustic signals like conversation) carry
under ideal conditions.

I believe the sats that scan for ELT signals are operated by the
Russians. They notify the FAA or somebody in the US when they pick up a
signal. I've heard that most ELT signals come from boats rather than
airplanes.