Page 10 AC 91-16 8/7/67 Bench Checks. Maintenance standards, practices, and limitations established in obtaining original equipment approval may be used for initial bench check and inspection standards. If it is determined later that these standards and practices will not maintain the equipment to Category II approval performance standards, the operator should establish additional tests, inspections and checks, more rigid calibration procedures and tolerances, etc., in order to retain these performance standards. All such changes which alter the approved maintenance program must be approved by the Federal Aviation Administrator.
Typical bench check procedures are shown in Attachment 1, Section VIII.
The equipment manufacturer's maintenance procedures may be incorporated in the bench check portion of the program by reference to the manufacturer's manual title and number if those procedures are found adequate to maintain the ability of the equipment to perform as approved for Category II operations. If exceptions to the manufacturer's maintenance procedures are required to meet Category II performance standards, they should be indicated as such in the maintenance program.
An example is shown in the bench check procedure for the Ajax Model 22-G glide slope receiver in Attachment 1, Section VIII, page 55.
f. Altimeter and Static System. If the 12-month altimeter bench check and static system test and inspection is entered in the airplane maintenance records, the requirements of FAR 91.170 will be met.
g. VOR Receivers. If the VOR receiving systems) are included in the approved maintenance program, the requirements of FAR 91.25(a) (1) will be met.
h. Repairs.
assuring that repairs performed on listed instruments and items of equipment will return the equipment to at least its original Category II approval condition before the airplane is used for Category Il operations. The procedure should include a positive means to notify the pilot in command when a listed instrument or item of equipment has not been so repaired. Examples of such forms and procedures have not been included in Attachment 1, Section V, because such procedures will have to conform to particular company organization.
i. Replacement. The Category II manual should contain a procedure to assure that equipment replaced with the same make, model, and design will provide system performance at least equal to Category II approval condition.
j . Alterations. All alterations to equipment that is required by FAR 91, Appendix A, Section 2, are approved by the FAA under the provisions of Section 3(b), (c), and (d) of that Appendix.
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AC 91-16 Page 11 8/7/67 Records. All tests, inspections, and bench checks performed on required equipment should be entered in the maintenance records required by FAR 43.9. Functional flight checks, although performed by pilots, must also be entered in the maintenance records in accordance with FAR 91, Appendix A, Section 4(a) (5). A separate record form for each item of equipment may be used if desired. Maintenance performed on this equipment at other than scheduled intervals must also be entered in the airplane maintenance records. In addition, an entry in the maintenance records is required showing the date, airport and reason for each discontinued Category II approach because of a malfunction of a listed instrument or item of equipment.
forms could also be used to record instrument and equipment malfunctions and failures occurring at times other than Category II operations if a means is provided to identify malfunctions occurring during Category II approaches. A method of recording scheduled inspections and bench checks, and discontinued Category II approaches is shown on pages 32 and 33 of Attachment 1, Section V. Space has been provided to identify the malfunctioning equipment and a description of the malfunction.
1. Maintenance Period Extensions. Operators may apply for extension of check, test and inspection periods after one 12-calendar-month maintenance cycle has been completed. In order to justify the extension, equipment performance and service history should show that the extension will not adversely affect the required level of performance of the Category II instruments and equipment. Application for extensions should be made by letter to the General Aviation District Office having jurisdiction of the area in which the operator is located. The following data should be made available:
(1) The currently approved maintenance program.
(2) Records of Category II approaches discontinued due to malfunctioning equipment.
(3) Number of actual and simulated Category II approaches completed during the past maintenance cycle, if available.
(4) Maintenance records of Category II equipment failures.
(5) Service history of known trends toward malfunctioning.
(6) Unit mean flight time between failures.
(7) Records of functional flight checks.
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Page 12 AC 91-16 8/7/67
m.. Time Increase.
by evaluation of the data submitted with the application for extension, will be major factors in determining the amount of maintenance period extension to be granted. Extension periods in most cases would be one calendar month for inspections and functional flight checks and four calendar months for bench checks.
Attachments 4
AC 91-16 Attachment 1 8/7/67 Page 1 (and 2)
A B C AIRWAYS
CATEGORY II MANUAL
AC 91-16 Attachment 1 8/7/67 Page 3 (and 4)
FOREWORD This Category II manual outline has been prepared as guidance material to assist in the preparation of the Category II manual required by FAR 91.34.
This manual, when approved by the FAA, completes one condition for the conduct of Category II operations. Compliance with its contents as approved is also required in order to conduct such operations.
Sections I through III provide for a statement of the applicability of the manual, the procedures and instructions for use of the CAT II airborne equipment and a description of the airborne systems and equipment.* Sections IV through VIll provide a partial example of a maintenance program designed to set forth the methods and procedures for maintaining and checking the Category II airborne equipment.
The guidance material contained herein does not preclude the development of Category II manuals by aircraft manufacturers, equipment manufacturers or those engaged in the installation and/or modifications of airborne equipment and systems intended for use in Category II operations.
*NOTE: Although not a manual requirement, operators may, if they desire, provide for copies of pilots' Category II letters of authorization as an item of content in the Category II manual.
AC 91-16 Attachment 1 8/7/67 Page 5 (and 6) Section I
APPLICABILITY
AC 91-16 Attachment 1 8/7/67 Page 7 (and 8) Section I - Applicability The Category II manual is required for the operation and maintenance of the listed Category II airplane and its instruments and equipment identified below. It must be available in the airplane at all times for use by the crew and to all persons performing maintenance on the listed Category II equipment.
An additional copy must be kept at the principal operations base and each copy must be kept current. Each page has been separately identified and approved by the Administrator.* No changes shall be made without the approval of the FAA Administrator except that additional copies of currently approved forms may be added.
The airplane to which this manual applies may be used to conduct Category II operations provided the instruments and items of equipment listed herein that are required for a particular Category II operation are:
1. Approved under Section 3 of Appendix A to FAR 91, and
2. Inspected and maintained in accordance with the approved maintenance program contained herein.
Aircraft N1234 Beech B-55 S/N 4255 * Date Inspector's Signature:
GADO (Identification) :
.... Attachment 1 AC 91-16 Page 9 (and 10) 8/7/67 Section II
OPERATING INSTRUCTIONS
AC 91-16 Attachment 1 8/7/67 Page 11 Section Il - Operating Instructions GENERAL• Statement concerning basic flight control guidance system or systems to be employed during Category II operation, such as a flight director system only or approach coupler system only or both systems when installed and approved for use.
2. CATEGORY II AIRBORNE EQUIPMENT - DESCRIPTION. Describe in this section of the Category ll manual the operational characteristics, capabilities and limitations appropriate to the airborne Category Il installed equipment:
a. The flight director system,
b. The automatic approach coupler (if applicable),
c. The approved system used to identify the decision height,
d. The instrumentation and display systems,
e. Automatic throttle control systems (if applicable),
f. Other systems and/or devices peculiar to the particular installation; i.e., computed go-around guidance equipment.
OPERATIONAL PROCEDURES AND INSTRUCTIONS - GENERAL. Set forth procedures and instructions developed by the operator to be used and adhered to by the crews which should include the following:
a. A procedure for determining the minimum runway length for use at destination airports (turbojet aircraft only).
b. Approach monitoring. Crewmember duties during a Category II approach should be clearly delineated.
c. Functional testing of the radar (radio) altimeter.
d. Resolution of the decision height. If operation is predicated on' the use of barometric altimeters, the errors determined to exist in the altimeter system, including correction for wheel height, are to be applied to the indicated altitude.
e. Use of RVR information.
f. Decision region. The region between the middle marker and the 100-foot point where the pilot must decide to either continue his approach or execute a go-around. Instructions to pilots should include the maximum raw ILS deviation which will permit a safe landing.
Attachment 1 AC 91-16 Page 12 8/7/67
g. Missed approach procedure. Crewmember duties during a missed approach should be clearly delineated in the Category Il manual.
h. Use of airborne low approach equipment including cross-over switching system, if provided for.
i. Instrument failure warning system
4. PROCEDURES FOR MANUAL APPROACH - FLIGHT DIRECTOR. Describe the procedures to be employed in the use of this equipment with respect to:
a. Mode selector (pilot and second in command).
b. Tuning of navigational receivers.
c. Course indicator check.
d. Course selection.
e. Pitch attitude setting.
f. Altitude hold.
g. Radio altimeter self-test (if appropriate).
h. Radio altimeter minimum altitude warning light and use of minimum decision altitude index (if appropriate).
PROCEDURES WHEN CLEARED FOR AN APPROACH WITH RESPECT TO:
a. Pilot-in-command's mode selector (heading to approach).
b. Second-in-command's mode selector (when appropriate).
c. Capture of localizer.
d. Capture of glide path.
e. Response of glide slope pointer approaching outer marker.
I. Glide slope capture indication and, if appropriate, appearance of runway symbol and status of pitch commands and V-bar commands.
g. Selection of missed approach heading and go-around pitch command.
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AC 91-16 Attachment 1 8/7/67 Page 13 (and 14)
h. Pilot-in-command and second-in-command flight director indicators, cross check for steering command and navigation displacement agreement.
Pilot-in-command and second-in-command duties and procedures as they relate to:
(1) Approach configuration of the airplane from outer marker to touchdown.
(2) Altitude and airspeed callout.
(3) Check for visual contact (specific phraseology).
(4) Indicating ground or lights.
j. Glide slope extension (if applicable).
k. Visual contact at 100 feet (second in command).
AUTOPILOT APPROACH. The same basic stabilized approach procedures should be established for the use of a coupled Category Il approach as those employed for a manual approach. If the performance of the autocoupler dictates a lesser flap setting, the pilot should not be required to upset the stabilized approach by making a configuration change to landing flaps during the approach.
7. MISSED APPROACH. Procedures and instruction regarding the use of the airborne equipment during the execution of a missed approach.
8. EMERGENCY OPERATION - WARNING FLAGS. A brief description of the purpose and function of the following warning flags:
a. Glide slope flag.
b. VOR/LOC flag.
c. Compass flag.
d. Computer flag.
e. Radio altimeter flag.
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AC 91-16 Attachment 1 8/7/67 Page 15 (and 16) Section III