Midcontinent 3300 Series Technical Document

INSTALLATION MANUAL AND
OPERATING INSTRUCTIONS
3300 Series Directional Gyro
Mid-Continent Instruments and Avionics Manual Number 9016481
9400 E 34th Street N, Wichita, KS 67226 USA Rev C, December 6, 2007
Phone [phone] Fax [phone]

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 2 of 12
FOREWORD
This manual provides information intended for use by persons who, in accordance with current
regulatory requirements, are qualified to install this equipment. If further information is required,
please contact:
Mid-Continent Instruments and Avionics
Attn: Customer Service Dept.
9400 E. 34th ST North
Wichita, KS 67226 USA
Phone [phone] Fax [phone]
We welcome your comments concerning this manual. Although every effort has been made to
keep it free of errors, some may occur. When reporting a specific problem, please describe it
briefly and include the manual part number, the paragraph/figure/table number, and the page
number. Send your comments to:
Mid-Continent Instruments and Avionics
Attn: Technical Publications
9400 E. 34th ST North
Wichita, KS 67226 USA
Phone [phone], Fax [phone]
[email protected]
www.mcico.com
Copyright 2007
Mid-Continent Instruments and Avionics

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 3 of 12
Table of Contents Page
Section 1 General Description 5
1.1 Purpose of Equipment 5
1.2 Physical and Functional Description 5
1.3 Gyro Warning Flag 5
1.4 Specifications 5
Section 2 Installation 7
2.1 General 7
2.2 Pre-Installation Inspection 7
2.3 Parts 8
2.3.1 Included Parts 8
2.3.2 Installer Supplied Parts 8
2.4 Equipment Location 8
2.5 Installation 8
2.6 Continued Airworthiness 9
Section 3 Operation 11
3.1 General 11
3.2 Starting Procedures 11
3.3 In-Flight Procedures 11
3.4 Equipment Limitations 11
Figures
1.1 Typical Directional Gyro Display Detail 6
2.1 Outline Drawing 10
2.2 Panel Cutout Dimensions 10
2.3 Voltage Control Switch Position 10
Tables
1.1 Physical Characteristics 5
1.2 Performance 6
2.1 Connector Pin Callout 10
Appendices
A DO-160E Environmental Qualification Form 12

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 4 of 12
Revision Detail
ECO Rev. Date Detail
A 1/25/07 Initial Release.
4811 B 2/27/07 Correct Typo on Append A & Sec 1.4: Temp. Variation “S2” was “C2”.
4943 C 11/29/07 Add comments for unit lighting in sections: 1.2, 1.3, 1.4, 2.5.B, 2.5.D,
2.5.G, 3.2.A. Change figure 2.1 and table 2.1. Add figure 2.3.

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 5 of 12
Section 1: General Description
1.1 Purpose of Equipment
The Model 3300 Directional Gyro (DG) is a gyroscopic directional indicator. This short-term
directional reference is used in conjunction with a magnetic compass. The directional gyro excels
in providing a direction indication during maneuvers when the magnetic compass develops
errors.
1.2 Physical and Functional Description
The 3300 Directional Gyro incorporates a spinning mass rotor. This rotor is gimbaled so the rotor
is free to move in all directions. The rotor, housed in the inner gimbal, incorporates an air
erection mechanism to keep the rotor spin axis perpendicular to the outer gimbal for optimum
performance. The outer gimbal is linked with a precision gear drive mechanism to the display
dial. The dial has five-degree graduations with numerals every thirty degrees. Every ninety
degrees is a cardinal reference letter (N, E, S, W). The display glass has a symbolic airplane for
quick heading reference as well as index marks every 45 degrees. The Push To Cage knob brings
the inner gimbal to level position, which is used primarily for startup. This Push To Cage knob is
also used to set the heading to agree with the magnetic compass. When the rotor speed is too
low for proper operation or if the unit is not receiving sufficient power, a warning flag drops into
view. The directional gyro requires 10 to 32 VDC input voltage. The 3300-11 incorporates internal
LEDs that operate on a user selectable 5V, 14V or 28V input from the aircraft lighting bus. For
the 3300-11, in addition to the warning flag coming into view, the dial (numeral) lighting will also
turn off to indicate invalid rotor speed or insufficient voltage. The symbolic airplane will remain lit
as long as sufficient voltage is present.
1.3 Gyro Warning Flag
A power warning circuit monitors rotor speed as well as the input voltage. Valid rotor speed is
determined as 70% of full speed and represents the minimum requirement for full functionality of
the unit. If either rotor speed or input voltage is insufficient (less than 10VDC), the gyro warning
flag comes into view. For 3300–11 only: In addition to the warning flag coming into view, the
dial (numeral) lighting will also turn off to indicate invalid rotor speed or insufficient voltage. The
symbolic airplane will remain lit as long as sufficient voltage is present.
1.4 Specifications
Physical Characteristics:
Qualification: FAA TSO-C5e
Environmental Qualification: RTCA DO-160E Environmental Category
D1S2AER(B1)XXXXXXZZAZ[ZC][WW]M[A3C3X]XXAX
Weight: 3300-10: 1.9 lbs
3300-11: 2.0 lbs
Dimensions: Length behind panel (not including connector)
4.65 inches long maximum.
3.28 inches high maximum.
3.28 inches wide maximum.
Mating Connector: MS3116F8-4S or equivalent (MCI P/N 9015514)
Cover Glass HEA (anti-reflective) coated
Instrument Mounting: Rear panel mount
Table 1.1

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 6 of 12
Performance:
Reliability 2500 Hour Mean Time Between Failure (MTBF)
Caging and Heading
Set Knob The "PUSH" knob will erect the gyroscope to case horizontal and engage the gear mechanism to set the heading position.
Drift Rate When the gyro is mounted to a rotating scorsby test stand tilted
to 3-degrees and set at 5 to 7 oscillations per minute the drift
shall be less than 4° in 10 minutes.
Warning Flag A gyro warning circuit provides for continuous monitoring of input
voltage and rotor speed. If either of these is insufficient, the red
warning flag will appear. In 3300-11, the dial lighting will turn off.
Operating Angle Limit
Heading: No Limit (360°) Pitch and Roll: 55° (all headings)
Lighting
(3300-11 only) Internal white LED with backlit dial. Lighting control voltage is user selectable for 5, 14 or 28VDC and has adjustable brightness.
Power Rating:
Starting
Will not exceed 1.4A at 14 VDC.
Will not exceed 0.6A at 28 VDC.
Running
0.37-0.51 at 14 VDC. 0.18-0.25 at 28 VDC.
Table 1.2
Warning
Flag On startup the warning flag will
show until the input
voltage and rotor
speed are sufficient
for proper operation.
If either of these
becomes insufficient
the warning flag will
come into view.
Symbolic
Airplane The symbolic airplane serves as a
heading reference
indicator. The point
at the nose indicates
the precise heading.
Index
Marks The index marks at 45-degree
increments are
provided for heading
reference.
Caging
and
Heading
Set Knob
Pushing this knob will
erect the gyroscope
for proper operation.
When the knob is
pushed and turned
the heading
indication can be
adjusted.
Typical Directional Gyro Display
Figure 1.1

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 7 of 12
Section 2: Installation
2.1 General
This section contains mounting, electrical connections and other information required for
installation. After installation of cabling and before installation of the equipment, ensure that
power is applied only to the pins specified in the Table 2.1 Connector Pin Callout.
The conditions and tests required for the TSO approval of this article are minimum performance
standards. It is the responsibility of those installing this article either on or within a specific type
or class of aircraft to determine that the aircraft installation conditions are within the TSO
standards. TSO articles must have a separate approval installation in an aircraft. The article may
be installed only if performed under 14 CFR Part 43 or the applicable airworthiness requirements.
CAUTION: GYROS ARE DELICATE INSTRUMENTS! THE FOLLOWING PRECAUTIONS
MUST BE OBSERVED!!
A. A high failure rate for gyroscopes can be directly related to rough or improper
handling.
Gyros are delicate and cannot withstand the shock of being dropped, jarred, or
struck by pieces of equipment. Do not place gyros on any hard surface. Pad with
generous foam. Handle like eggs!
B. To prevent damage to a gyro, the instrument should be transported to and from the
aircraft in its original shipping container. If this is impractical, the gyro should be
hand-carried carefully in an upright position.
C. A gyro should never be removed while it is spinning or running down. The instrument
normally operates at high RPM and may take 10 minutes or longer to run down. If it
is removed while running and tilted more than 20 degrees, the gyro can develop a
gimbal lock. The gimbal will tumble and start to spin. If gimbal lock occurs while the
rotor is turning, the gimbal may spin fast enough to damage the gimbal bearings,
requiring overhaul.
D. A malfunctioning gyro should be handled with the same care given a new
instrument. Most malfunctioning instruments can be repaired and returned to
service. Using proper handling procedures during removal prevents additional
damage and helps ensure possible reuse.
2.2 Pre-installation Inspection
A. Unpacking
Carefully remove the directional gyro from shipping container. The shipping
container and packing materials should be retained for use should the gyro
require future shipment.
B. Inspect for Damage
Inspect the shipping container and directional gyro for any signs of damage
sustained in transit. If necessary, return the directional gyro to the factory using
the original shipping container and packing materials. File any claim for damages
with the carrier.

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 8 of 12
2.3 Parts
2.3.1 Included Parts
A. Model 3300-( ) Directional Gyro
B. Mating Connector, MS3116F8-4S or equivalent (P/N 9015514)
C. Installation Manual (P/N 9016481)
2.3.2 Installer Supplied Parts
A. Mounting Screw, 6-32UNC-2A. Three (3) required. (3/4” long screws are suggested
for panel thickness between 0.05 and 0.19, but may not be optimum in some
installations. The installer will need to determine what is correct for a particular
installation.)
CAUTION: Do not exceed 0.75” screw depth into bezel!
2.4 Equipment Location
The directional gyro should be located within the aircraft in accordance with the following
considerations:
A. The gyro is ideally located in the instrument panel directly within the pilot’s normal
line of sight. The "PUSH" knob should be within easy reach. Installations that result
in viewing angles in excess of 30 degrees may reduce display readability.
B. Compare the space requirements of the gyro with the installation area being considered.
C. The power cable should not run adjacent to heaters, engine exhausts, or other heat
sources. Also, take care to route and tie the cable away from aircraft controls and
cables.
2.5 Installation
Install the Directional Gyro in accordance with the aircraft manufacturer’s instructions and the
following steps:
A. Refer to Figure 2.1 and Table 2.1 for installation dimensions and electrical information.
The recommended circuit breaker size is 2A. The minimum wire size is 22 AWG.
B. For 3300-11 only: Locate the lighting voltage switch on the side of the unit. If
required, switch the lighting voltage to the aircraft lighting bus voltage. Using a small
pointed object, push the switches to select the lighting voltage per Fig 2.3. A
brightness level adjustment is also located near the voltage switch on the side of the
unit. The brightness level should be set for comfortable viewing at night.
C. Ensure the available instrument panel cutout meets the requirements of the gyro.
See Fig 2.2 for details.
D. Attach aircraft electrical system cable to the instrument’s connector per connector pin
callout on Table 2.1 and insert the gyro into the instrument panel cutout. For 3300-
10, as indicated on the connector pin callout, either pin B or C may be used for
power input. The pins are connected internally and are provided for ease of
installation. There is NO need to apply power to both pins B and C. For 3300-11,
lighting power should be applied to pin B since pin B and C are not internally
connected. Only Pin C should be used for power input.

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 9 of 12
E. Secure the gyro to the instrument panel using the screw sizes called out in the
mounting instructions. Length of screws will be determined by aircraft instrument
panel thickness. The aircraft manufacturer or the installation facility is responsible for
supplying appropriate installation hardware. For ease of installation, the caging knob
may be removed. This is accomplished without tools by pulling straight out. To
reinstall the knob, align the flats on the knob and shaft and push the knob in until it
is seated.
F. Apply the correct input power to the gyro.
G. The Warning Flag shall be out-of-view within 5 minutes of startup.
NOTE: For 3300–11 only:The dial lighting (text, numerals, and grads) will not
function until the rotor is near full speed. The symbolic airplane will be lit when
power is applied to the unit.
H. Verify that the caging shaft is not rubbing on the panel, which can cause the knob to
stick.
2.6 Continued Airworthiness
No periodic scheduled maintenance or calibration is necessary for continued airworthiness of the
3300 series Directional Gyro. If the unit fails to perform to specifications, it must be removed and
serviced by a qualified service facility.

Mid-Continent Instruments and Avionics, Wichita, KS
Rev C, December 6, 2007 Manual Number 9016481 Page 10 of 12
Figure 2.1 Outline Drawing
Fi
g
ure 2.2: Panel Cutout Dimensions
Connector: MS3112E8-4P
A Ground (DC)
B Lighting Input (-11 Only)
C +10VDC to 32VDC Input*
D Reserved
* For –10: Supply power to pin B or C
Table 2.1: Connector Pin Callout
Figure 2.3:
Lighting Control
Switch Position