----[Please read http://ercoupers.com/disclaimer.htm before following any
advice in this forum.]----
Guys .
After reading the last posts, I might add my 2 cents worth.
Like being mentioned, the compass is very important in a electrical failure
and of course to readjust your DG if you still have one.
Assumed that you fly mostly by GPS, you don't give much of the wobbly
indication , your compass gives you.
Only if your GPS fails you, you start caring for that device. That can also
happen with empty batteries, a power cable failure to the GPS etc.
Thinking that way, I adjusted the compass with the radios ON, but my GPS NOT
mounted. ( I use velcro to mount the GPS at the panel close to the compass)
I also noticed the heading of the compass before and after I started the
engine. I could not find a difference there. So I assume that having the
radios on is good enough in my plane.
One more thought. At times when you need the compass most, it does not
really matter if it is one or two degrees off.
Example (a scary one)
When I encountered ones an overcast with a closing cloud cover above me with
a non functional VOR receiver, plus being lost as soon as the clouds closed,
all I needed to know was how to fly home. After awakening the VOR instrument
to one more weak position report, I could locate myself, knew that south was
my direction, roughly . And that was all what was needed.
I also flew quiet some Cross country without a GPS, just by compass and the
flaky VOR receiver. My experience is that even the best adjusted compass
does not help you when it comes to adjust for the wind drift. You'll have to
compare your route with the map anyway and fly an arbitrary number.
It is rare that your calculated course actually matches true flown course.
Still, your compass should be as correct as possible within a few degrees.
Hartmut
----- Original Message -----
From: "Roy Stubbs" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Thursday, December 29, 2005 4:37 PM
Subject: RE: [COUPERS-TECH] Deviation chart - engine on or off?
----[Please read http://ercoupers.com/disclaimer.htm before following any
advice in this forum.]----
Bob is right - don't discount the magnetic compass.
I remember doing cross countries in a J-3 cub using a magnetic compass.
It can be done; you just have to really pay attention.
Now, I don't leave home without my Garmin. Roy N70UF
-----Original Message-----
From: Bob Branch [mailto:[EMAIL PROTECTED]
Sent: Thursday, December 29, 2005 10:20 AM
To: [email protected]
Subject: Re: [COUPERS-TECH] Deviation chart - engine on or off?
----[Please read http://ercoupers.com/disclaimer.htm before following
any
advice in this forum.]----
Don
While I am firmly of the opinion an aircraft compass is a woefully
inadequate device, especially vfr, the odd thing is ifr it can save
you
bacon if you have an electrical failure. I've had the experience
during
ifr
training of having to fly an approach under simulated complete
electrical
failure and one engine (multi of course).
Of interest to many might be my experience when I went to swing the
new
out
of the box airpath compass in my ercoupe. There was about a 14 degree
error
before I swung and adjusted it. So just setting correctors to zero and
forgetting it is not a good plan. My experience with compasses over
the
years in all types of vehicles is that this is not unusual. That is
why
the
corrector magnets are in them. Some aircraft, Mooney's most notably,
can
be
just aweful to get corrected decently. My avionics shop did not want
to
even
try to do a verticle compass card because of the troubles they have
had
with
them in aother aircraft in the past. Perhaps someone who has one in an
ercoupe could relate to where they mounted (glare shield, panel,
winshield
post) and if they had any issues getting it adjusted. I know the
company
who
makes them makes available seperate corrector magnets... man that is a
tough
mounting to get those issues worked out... been there, done that.
Anyway,
a
15 or more degree error can cause you to certainly miss the town or
airport
you are trying to fly over. Everything does look rosey when all the
electronics are working, but stuff happens. Satellites get knocked out
by
solar storms, electrical systems fail, and we just plain get lost.
When
all
else fails, there is still nothing more reliable than a well swung
compass.
And if it happens, looking at the correction card and seeing
corrections
of
under 5 degrees can make your day and your math alot easier.
Swinging I know sounds like a tough time consuming issue but it really
isn't. It will take you less than 30 minutes to do it right and that
includes really nailing down the correctors to the best you can get
them.
Once you have them, and 2 or 3 passes over the rose should get the n-s
and
e-w correctors done, then its just drive over and write down the
numbers.
When I used to race sailboats it would take a 3 hour evening session
in
dead
calm water and wind to do it. We'd align over about a 1/4 mile
distance
for
each 10 degrees of the compass. Its much easier in an airplane with a
nice
compass rose painted on the airport.
bob branch
N99891
========================================================================
==
====
To leave this forum go to: http://ercoupers.com/lists.htm
Search the archives on http://escribe.com/aviation/coupers-tech/
==============================================================================
To leave this forum go to: http://ercoupers.com/lists.htm
Search the archives on http://escribe.com/aviation/coupers-tech/
==============================================================================
To leave this forum go to: http://ercoupers.com/lists.htm
Search the archives on http://escribe.com/aviation/coupers-tech/
