No
5
Subjects:
Training:
Avionics Schools
Instruments: Single-Cue ADI
GPS: Rollover Error
Navcom: Obsolete Mk12B
Training
Avionics Schools
Q.
Can you provide a list of schools which teach
avionics?
A.
Most schools listed below are
FAA-certified to teach avionics and are listed by
state. Some offer two-year training for the
technician. Others offer 4-year engineering
courses. We welcome additional listings from
schools not shown, from anywhere in the world.
Please submit information on your program to:
avionicschools@avionics.com
Alabama
AlAlabama
Aviation and Tech College
246
Club Manor Dr.
Mobile,
AL 36615
Alaska
University of Alaska Anchorage
2811
Merrill Field
Anchorage,
AK 99501
California
Northrop-Rice Institute of Tech
8911
Aviation Blvd.
Inglewood,
CA 90301
Solano Cohn College School of Aero
4000
Suisun Valley Rd.
Suisun
City, CA 94585
Colorado
Colorado Aero Tech Inc.
10851
W. 120th St.
Broomfield,
CO 80020
Connecticut
Platt
Regional Vo Tech School
Great
Meadow Rd.
Stratford,
CT 06497
Florida
Embry
Riddle Aeronautical
University
600
South Clyde Morris Blvd.
Daytona,
FL 32114
Georgia
Heart
of Georgia Technical Institute
Eastman
Dodge Airport
Old
Eastman-Dublin Rd. GA
Hwy. 46
Eastman,
GA 31023
Illinois
Parks
College of St. Louis Univ.
Falling
Springs Rd.
Cahokia,
IL 62206
Southern Illinois Univ. Avn. Tech
Southern
Illinois Airport
607
N. Airport Rd.
Carbondale,
IL 62901
Indiana
Purdue
Univ. Dept. of Aviation Tech.
Purdue
University Airport
Dept.
of Aviation Tech West
Lafayette,
IN 47906
Kansas
Kansas
State University-Salina
2409
Scanlan
Salina,
KS 67401
Missouri
Linn
Technical College
McDonnell-Douglas-Green
Aviation Complex
Linn,
MO 65051
Trans World Technical Academy
533
Mexico City Ave.
Kansas
City, MO
64153
|
M
Montana
Helena College of Technology
2300
East Poplar
Helena,
MT 59601
New York
College
of Aeronautics
La
Guardia Airport
Flushing,
NY 11371
Oklahoma
|
Spartan
School of Aeronautics
8820
East Pine St.
Tulsa,
OK 74158
Tulsa County Area Vo Tech School
1211
West 36th St. North
Tulsa,
OK 74127
Oregon
Lane Community College
4000
E. 30th Ave.
Eugene,
OR 97405
Pennsylvania
Penn
College of Technology
One
College Ave.
Williamsport,
PA 17701
Pittsburgh
Institute of Aeronautics
Allegheny
County Airport
West
Miffline, PA 15122
Texas
Letourneau
University
Div.
of Aerospace Science
2100
S. Nobberly Ave.
Longview,
TX 75602
Utah
Salt
Lake Community College
4600
South RedwoodRd.
Salt
Lake, UT 84131
Utah
State University
Utah
State Univ. College Engineering
ITE
Dept.
Logan,
UT 94321
West
Virginia
Fairmont State College
Robert C. Byrd National Aerospace Education Ctr.
1050 E. Benedum Industrial Drive
Bridgeport, WV 26330
Wisconsin
Blackhawk
Technical College
4720
US Hwy. 51 South
Janesville,
WI 53545
Fox
Valley Technical School
3601
south County Rd. 1
Oshkosh,
WI 54903
|
Instruments
Single-Cue
ADI (Attitude Director Indicator)
Q. Is a “single-cue ADI” one
in which a command bar moves in
two directions to provide pitch and roll
commands with one symbol?. (From an airframe
builder in Seattle.)
A..
The answer is “yes”. For readers not familiar
with the instrument, here’s some background.
Since 1927 pilots
have flown with an artificial horizon for pitch
and roll guidance
when they couldn’t see out.
To navigate, however,
they also scan
other instruments---VOR , altimeter, airspeed,
vertical speed, etc. Pilots of light planes still do
this, but it’s too primitive (and difficult) for
the crew in high performance aircraft.. About 40
years ago the problem was solved by the “ADI”--
Attitude Director Indicator.
It’s an artifical horizon, but also
gathers attitude, navigation and
performance data and concentrates it into a
single “command bar”. As our illustration
above shows, it's
V-shaped bar which lies just under another
V-shape, or wedge, that represents the wings of the airplane.
The
pilot begins the process
by storing his
desired course, altitude and other flight
parameters into a
computer which drives
the Command
bar. As the flight progresses, the bar rises to
tell the pilot to increase altitude, tilts left or
right to
command a
turn, or any combination to get the airplane
on the
desired course and altitude. The pilot
doesn’t have to scan across the instrument panel
for a half-dozen different gauges---he just
looks at the wings symbol on his ADI and keeps it
nestled intimately under the Command bar,
following it wherever it leads.
It’s also handy during the busy time of a
go-around; the
pilot hits a lever, then
follows the Command bar which computes and
guides the maneuver.
Another important
ADI function is to help the pilot monitor
the autopilot. When flying hands-off, the crew
observes the instrument to see what
commands are delivered to the autopilot.
All the
computations come from the same source.
The Command bar
is called “single cue” because
it combines pitch and roll in one V-shaped
symbol.
Earlier, there was a
two-cue system, which had
separate cross-pointers for those
attitudes.
The single-cue won out because of
its superior human factors.
HF
Radio
Antenna Installation
Q. I'm thinking of getting an HF radio
for my Ercoupe. I'm a ham operator and long
cross-countries get boring at 95 kts. My questions
are: how do external HF antennas work; what are
"reel" systems, what about antenna
tuners and what antennas and radios do people use
to ferry small aircraft across the ocean?
I also wondered about mounting a mobile ham
radio in my plane.
A. First,
how do external antennas for HF work.
The HF
antenna on large aircraft is usually
inside the vertical rudder fin, behind a
composite (non-metal) fairing. On the
Boeing 707, however, the HF antenna is a
horizontal mast that points forward from the
top of the rudder fin.
A "reel"
type HF antenna is very old and rarely used.
It is reeled out behind the airplane where
it trails in the air stream. It was,
in fact, used by Amelia Earhart in 1937
during her attempt at circling the globe. But
the lady was so impatient to take off, she didn't
wait for a replacement trailing wire for her most
dangerous leg over the Pacific. As a
result, the Coast Guard couldn't hear her
distress calls and the rest is tearful history.
You do need an antenna
tuner because HF waves are so long and aircraft
antennas so short. Because you're a
ham, you typically work one band at a time and
need only a simple tuner to resonate the
antenna to the frequency. During oceanic
flight in an airliner, however, pilots do a lot of
band-hopping to seek good propagation
conditions (skip angles) no matter where they are,
night or day. Because it is difficult
for the co-pilot, while half-way
across the ocean, to climb out
on the rudder fin to set taps on the
tuning coil, tuners are automatic. The
HF transceiver sends a low-level test signal
to the antenna and measures how much bounces
back. You probably recognize this as VSWR
(Voltage Standing Wave Ratio). The
tuner seeks the lowest VSWR, which is the point
where the antenna is resonant to the signal
from the transmitter. This automatic tuning
permits a relatively short aircraft antenna to be
used on a wide range of frequencies.
Installing an HF antenna on a puddle jumper
like your Ercoupe has been done by running
the antenna outside the fuselage, fastening it
with an insulated stand-off, then running
the wire to the top of the rudder fin, then out to
a wingtip. Although some have been
installed with an FAA 337 form, you might want to
consult with your avionics shop to see what
the FAA avionics inspector thinks about it. It
would seem that a better approach would be a
loaded vertical whip, using much the same
techniques hams have been using for years for
automobile mobile operation.
You ask how people
ferry small aircraft over the
ocean? Ferry pilots used to cross
oceans with little more than a compass, one
VHF radio and ferry tanks. Because VHF
communications are lost at about 100 miles
offshore, the pilots would get on 121.5 (which
everyone guards over water for emergencies) and
talk to the nearest airliner. (There are
always about 200 airliners strung out across the
Atlantic at any one time.) Airline pilots
are very obliging in using their HF radios
to relay the position of a small airplane.
The greatest ferry pilot of them all was Charles
Lindbergh. We at avionics.com don't
like to admit it, but Lindy had no radio at
all. (Radios in 1927 weighed nearly half as
much as the airplane.) What Lindy did was go
to his local library before the flight, lay a
string on a globe between New York and Paris and
figure out hourly changes in magnetic course
for a Great Circle route. After crossing the
Atlantic he hit the coast of Ireland within five
miles of his flight-planned route! (What
books about Lindbergh fail to mention, however, is
that he was driven off course by storms so many
times that all the errors cancelled).
For many years , ferry
pilots used ADF (if they had one), receiving
signals only during the beginning and end of the
trip. However, they often cross the
Atlantic via Greenland and Iceland, with 600 miles
as the longest overwater leg. About 20 years ago,
they began using Loran which has solid coverage
over the North Atlantic. Today, of
course, a $100 pocket GPS gives better
navigation than the triple laser gyro's on
jumbo jets.
For
communications, a ferry pilot may rent an HF
radio, which is often plunked down on
the co-pilot's seat or placed behind the front
seats. A temporary antenna is then strung on the
airframe, as mentioned above.
For your
installation, we suggest you consider the
well-known techniques of mobile HF ham
radio, that is, a loaded whip on one band.
Just be sure the local FAA will accept the
antenna and its mounting. Also, look into
using the same technique as the ADF sense antenna,
which is a long wire from a standoff on the cabin
roof to the tip of the rudder fin.
This would require an antenna tuner in the
cabin to resonate the wire.
