Backup alternator PA28-235...

Hi all, does anyone know if the PA28-235 platform can handle a backup
alternator? If so, how would one be mounted? If not, what is the
substitute alternative? Any suggestion on how many hours in labor &
costs would be appreciated.

Thank you.

USA

Hi all, does anyone know if the PA28-235 platform can handle
a backup alternator? If so, how would one be mounted? If not,
what is the substitute alternative? Any suggestion on how many
hours in labor & costs would be appreciated.

I've never heard of one, but you might try asking this over on the Cherokee
235/236 Owner's Group website. See it at
http://www.pa28.com/cherokee235/home.htm
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

USA wrote:
Hi all, does anyone know if the PA28-235 platform can handle a backup
alternator? If so, how would one be mounted? If not, what is the
substitute alternative? Any suggestion on how many hours in labor &
costs would be appreciated.

Thank you.

USA


I have a friend with a PA-28-161, although that's not relevant to the
solution. He made himself a portable pack with a couple of gel-cell
batteries and a cigaret lighter type plug. Gives him an hour or so of
backup power for the radio and GPS if the plane's system goes down.
Easy to carry, charges externally and compatable with any 12V system,
with a plug. I don't know what the FAA would say, but if I lost power
in the clouds, I'd call it an emergency and take PIC responsibility.

John Stevens
PP-ASEL

wrote

I have a friend with a PA-28-161, although that's not relevant to the
solution. He made himself a portable pack with a couple of gel-cell
batteries and a cigaret lighter type plug. Gives him an hour or so of
backup power for the radio and GPS if the plane's system goes down.
Easy to carry, charges externally and compatable with any 12V system,
with a plug. I don't know what the FAA would say, but if I lost power
in the clouds, I'd call it an emergency and take PIC responsibility.

I assume he charges it at home, and not from the plane's electrical system?

The voltage put out by a plane or car's electrical system is too high, and
will reduce the capacity and life of gel cells. A schottie diode put in a
charging line will reduce the voltage from an alternator, to make it safe
for charging the gel cells.
--
Jim in NC

USA wrote:
Hi all, does anyone know if the PA28-235 platform can handle a backup
alternator? If so, how would one be mounted? If not, what is the
substitute alternative? Any suggestion on how many hours in labor &
costs would be appreciated.

First off, I don't doubt a method could be devised to install a backup
alternator. However, this would be considered a major alteration
requiring either an STC or field approval. In this day and age, I
doubt you would get a field approval (even if someone previously got
one for the same thing - the pracice of accepting prior field approvals
as data for new ones has gone away, unfortunately) and AFAIK there is
no STC.

You can search all the existing STC's for a particular make and model
on www.airweb.faa.gov/stc - be sure to check PA28-235 and PA28 series.
It's not terribly searchable but you can always cut the text from your
favorite browser and paste it into a text editor with search capability
if you so wish.

If there is no STC (and I suspect there is not) you're looking at tens
of thousands to make it happen.

I suggest that a much better approach would be to carry a handheld
radio and GPS. Depending on what you choose, cost can vary from $500
to $3000. Also, you might consider adding a BNC connector allowing
your handheld com to use an external antenna in case power goes out.
Total cost for that should not exceed $200.

Michael

I lost my alternator 3 times in my 180 before I figured out why is was going
bad. I flew for more than an hour and when I landed it stilled cranked like
it was charged.
Why would you need an extra one. Wouldn't you just land at the nearest
airport if you where IMC.
"Michael" wrote in message
oups.com...
USA wrote:
Hi all, does anyone know if the PA28-235 platform can handle a backup
alternator? If so, how would one be mounted? If not, what is the
substitute alternative? Any suggestion on how many hours in labor &
costs would be appreciated.

First off, I don't doubt a method could be devised to install a backup
alternator. However, this would be considered a major alteration
requiring either an STC or field approval. In this day and age, I
doubt you would get a field approval (even if someone previously got
one for the same thing - the pracice of accepting prior field approvals
as data for new ones has gone away, unfortunately) and AFAIK there is
no STC.

You can search all the existing STC's for a particular make and model
on www.airweb.faa.gov/stc - be sure to check PA28-235 and PA28 series.
It's not terribly searchable but you can always cut the text from your
favorite browser and paste it into a text editor with search capability
if you so wish.

If there is no STC (and I suspect there is not) you're looking at tens
of thousands to make it happen.

I suggest that a much better approach would be to carry a handheld
radio and GPS. Depending on what you choose, cost can vary from $500
to $3000. Also, you might consider adding a BNC connector allowing
your handheld com to use an external antenna in case power goes out.
Total cost for that should not exceed $200.

Michael

Aluckyguess wrote:
Why would you need an extra one. Wouldn't you just land at the nearest
airport if you where IMC.


Aren't you the optomist.

I've lost the alternator on a single engine solid IFR flight over the mountains
one night and it ain't much fun. I got down OK before the battery went dead but
it was definitely nerve wracking. That's why I like twins. It's not the extra
engine so much as the extra alternator and vacuum pump. I've only had a very
few engine failures over the years but I've had several alternators and vacuum
pumps go TU.

When you fly crap as a freight dog you learn to appreciate redundancy.



--
Mortimer Schnerd, RN

VE

Point taken, but the original poster sounded like he owned his own plane. He
could probably spend the same amount of money on getting a new alternator
every year for ten years and still come out ahead. Or he could get a new
alternator and fix other problems that are more likely to cause a problem. I
will take a well maintained single of a bucket of bolts twin any day.

"Mortimer Schnerd, RN" wrote in message
...
Aluckyguess wrote:
Why would you need an extra one. Wouldn't you just land at the nearest
airport if you where IMC.


Aren't you the optomist.

I've lost the alternator on a single engine solid IFR flight over the
mountains one night and it ain't much fun. I got down OK before the
battery went dead but it was definitely nerve wracking. That's why I like
twins. It's not the extra engine so much as the extra alternator and
vacuum pump. I've only had a very few engine failures over the years but
I've had several alternators and vacuum pumps go TU.

When you fly crap as a freight dog you learn to appreciate redundancy.



--
Mortimer Schnerd, RN

VE

A set of relays and diodes would allow the installation of a
second battery and a great deal of redundancy at fairly low
cost and weight. The standard alternator would charge both
batteries, only the second battery would be connected to the
essential bus of lights and avionics. A battery failure
kills the alternator on most aircraft and thus kills the
entire system. Having two isolated batteries give
redundancy as long as the bus is able to shed load.

Beech uses self-exciting alternators [and a generator will
produce power w/o a battery (but it isn't well filtered)].
On a Beech you can turn the battery OFF and still operate.
But in most Cessna and Piper aircraft the battery must be ON
for the alternator to function. A second battery and
modified bus can give redundancy. Load shedding can be
automatic or manual. You need to have diodes to control
current flow.


--
James H. Macklin
ATP,CFI,A&P

"soxinbox" wrote in message
...
| Point taken, but the original poster sounded like he owned
his own plane. He
| could probably spend the same amount of money on getting a
new alternator
| every year for ten years and still come out ahead. Or he
could get a new
| alternator and fix other problems that are more likely to
cause a problem. I
| will take a well maintained single of a bucket of bolts
twin any day.
|
| "Mortimer Schnerd, RN"
wrote in message
| ...
| Aluckyguess wrote:
| Why would you need an extra one. Wouldn't you just land
at the nearest
| airport if you where IMC.
|
|
| Aren't you the optomist.
|
| I've lost the alternator on a single engine solid IFR
flight over the
| mountains one night and it ain't much fun. I got down
OK before the
| battery went dead but it was definitely nerve wracking.
That's why I like
| twins. It's not the extra engine so much as the extra
alternator and
| vacuum pump. I've only had a very few engine failures
over the years but
| I've had several alternators and vacuum pumps go TU.
|
| When you fly crap as a freight dog you learn to
appreciate redundancy.
|
|
|
| --
| Mortimer Schnerd, RN
|
| VE
|
|
|
|
|
|
|
|

I guess it's a pilot decision, which would make you feel safer, a second
battery or 7 more gallons of gas?
I'll go with the gas.

"Jim Macklin" wrote in message
news:gEqkg.38278$ZW3.10257@dukeread04...
A set of relays and diodes would allow the installation of a
second battery and a great deal of redundancy at fairly low
cost and weight. The standard alternator would charge both
batteries, only the second battery would be connected to the
essential bus of lights and avionics. A battery failure
kills the alternator on most aircraft and thus kills the
entire system. Having two isolated batteries give
redundancy as long as the bus is able to shed load.

Beech uses self-exciting alternators [and a generator will
produce power w/o a battery (but it isn't well filtered)].
On a Beech you can turn the battery OFF and still operate.
But in most Cessna and Piper aircraft the battery must be ON
for the alternator to function. A second battery and
modified bus can give redundancy. Load shedding can be
automatic or manual. You need to have diodes to control
current flow.


--
James H. Macklin
ATP,CFI,A&P

"soxinbox" wrote in message
...
| Point taken, but the original poster sounded like he owned
his own plane. He
| could probably spend the same amount of money on getting a
new alternator
| every year for ten years and still come out ahead. Or he
could get a new
| alternator and fix other problems that are more likely to
cause a problem. I
| will take a well maintained single of a bucket of bolts
twin any day.
|
| "Mortimer Schnerd, RN"
wrote in message
| ...
| Aluckyguess wrote:
| Why would you need an extra one. Wouldn't you just land
at the nearest
| airport if you where IMC.
|
|
| Aren't you the optomist.
|
| I've lost the alternator on a single engine solid IFR
flight over the
| mountains one night and it ain't much fun. I got down
OK before the
| battery went dead but it was definitely nerve wracking.
That's why I like
| twins. It's not the extra engine so much as the extra
alternator and
| vacuum pump. I've only had a very few engine failures
over the years but
| I've had several alternators and vacuum pumps go TU.
|
| When you fly crap as a freight dog you learn to
appreciate redundancy.
|
|
|
| --
| Mortimer Schnerd, RN
|
| VE
|
|
|
|
|
|
|
|