Advisory Circular (AC) No. 500-021 Issue 1

Certification of a Change of Pilot-In-Command Seat for Single-Pilot Operations for Rotorcraft

File No.: 5009-32-4 AC No.: 500-021
RDIMS No.: 1885805-V2 Issue No.: 01
Issuing Branch: Aircraft Certification Effective Date: 2006-10-20

1.0. Introduction

1.1 Purpose
1.2 Applicability.
1.3 Description of Changes

2.0 References

2.1 Reference Documents
2.2 Cancelled Documents
2.3 Definitions and Abbreviations

3.0 Background

4.0 Applicable Certification Requirements

5.0. Aircraft Configuration

5.1 Traditional Certification Approach
5.2 Certification Requirements

6.0 Certification Tests

6.1 Cockpit Evaluation
6.2 Normal Procedures
6.3 Emergency Procedures

7.0 Rotorcraft Flight Manual

7.1 Limitations
7.2 Normal Procedures
7.3 Emergency/Abnormal Procedures
7.4 Performance

8.0 Contact office

1.0 Introduction

This Advisory Circular (AC) describes an acceptable means, but not the only means of demonstrating compliance with regulations and standards.  This AC in and of itself does not change, create, amend or permit deviations from regulatory requirements nor does it establish minimum standards.  The applicant may elect to follow an alternate method, which must be acceptable to Transport Canada.

1.1 Purpose

The purpose of this AC is to document a means of compliance in respect of the certification of a change of pilot-in-command seat for single-pilot operations for rotorcraft.

1.2 Applicability

This document is applicable to all Transport Canada Civil Aviation personnel, delegates and industry.

1.3 Description of Changes

Not applicable. 

2.0 References

2.1 Reference Documents

It is intended that the following reference materials be used in conjunction with this document:

  1. Chapter 513 of the Airworthiness Manual (AWM)—Approval of Modification and Repair Designs;
  2. Chapter 527 of the AWM—Normal Category Rotorcraft; and
  3. Chapter 529 of the AWM—Transport Category Rotorcraft.

2.2 Cancelled Documents

Not applicable.

2.3 Definitions

The following definitions and abbreviations are used in this document:

  1. Automatic Flight Control System (AFCS);
  2. Directional Gyro (DG);
  3. High Pressure Turbine Speed (N1);
  4. Horizontal Situation Indicator (HSI);
  5. Instrument Flight Rules (IFR);
  6. Left Hand (LH);
  7. Pilot-In-Command  (PIC)
  8. Power Turbine Inlet Temperature (T5);
  9. Power Turbine Speed RPM (NP);
  10. Radio Magnetic Indicator (RMI);
  11. Revolutions Per Minute (RPM);
  12. Rotor RPM (NR);
  13. Rotorcraft Flight Manual Supplement (RFMS); and
  14. Visual Flight Rules (VFR).

3.0 Background

  1. There has been a recent increase in requests to certify rotorcraft to be used for vertical reference external load operations using a minimum crew of one pilot seated in the left seat. The rotorcraft proposed for left seat vertical reference external load operations were originally certified for a minimum crew of one pilot seated in the right seat. The configurations proposed by the applicants generally did not meet all the requirements of the applicable certification basis.
  2. This guidance has been written assuming the original minimum crew was one pilot seated in the right seat and that the new certified configuration is one pilot seated in the left seat.  It can also be used for crew seat changes that are not related to vertical reference external load operations.
  3. The means of compliance documented herein, will help to ensure that the traditional approach is used consistently in future certification work on new and existing design approvals issued under Chapter 513 of the Airworthiness Manual.

4.0 Applicable Certification Requirements

The applicable certification requirements for transport category rotorcraft are found in Chapter 529 of the AWM and those for normal category rotorcraft are found in Chapter 527 of the AWM. Compliance with the certification requirements that could be affected by a change in minimum flight crew number, position or both, are listed below, with the 5XX indicating either Chapter 527 or 529 of the AWM as applicable.

  1. 5XX.141(b) Flight Characteristics, General;
  2. 5XX.151 Flight Controls;
  3. 5XX.161 Trim Control;
  4. 5XX.171 Stability: General;
  5. 5XX.671 Control Systems, General;
  6. 5XX.672 Stability Augmentation, automatic, and power-operated systems;
  7. 5XX.771 Pilot Compartment;
  8. 5XX.773 Pilot Compartment View;
  9. 5XX.777 Cockpit Controls;
  10. 5XX.785 Seats, berths, litters, safety belts, and harnesses;
  11. 5XX.1301 Function and installation;
  12. 5XX.1303 Flight and Navigation Instruments;
  13. 5XX.1305 Powerplant Instruments;
  14. 5XX.1307 Miscellaneous Equipment;
  15. 5XX.1309 Equipment. Systems and Installations;
  16. 5XX.1321 Arrangement and Visibility;
  17. 5XX.1329 Automatic Pilot Systems;
  18. 529.1333 Instrument Systems;
  19. 5XX.1335 Flight Director Systems;
  20. 5XX.1337 Powerplant Instruments;
  21. 5XX.1357(d) Circuit Protective Devices;
  22. 5XX.1381 Instrument Lights;
  23. 5XX.1383 Landing Lights;
  24. 5XX.1521 Powerplant Limitations;
  25. 5XX.1523 Minimum Flight Crew;
  26. 5XX.1525 Kinds of Operations;
  27. 5XX.1541 Markings and Placards, General;
  28. 5XX.1559 Limitations Placard;
  29. 5XX.1581 Rotorcraft Flight Manual, General;
  30. 5XX.1583 Operating Limitations; and
  31. 5XX.1585 Operating Procedures.

5.0 Aircraft Configuration

5.1 Traditional Certification Approach

The configuration changes generally proposed for vertical reference external load operations consist of the following:

  1. Bubble window installed in left door;
  2. Instrument cluster installed in the left door/floor that was visible to the pilot when performing vertical reference work with small head/eye movements. If the N1 and T5 indicators were not reproduced in the door/floor instrument cluster then a procedure was developed to ensure that the pilot was aware of what torque corresponded to the first engine limit reached under the prevailing atmospheric conditions. The instrument cluster included the following:

    1. Torque indicator;
    2. NR/NP tachometer;
    3. Fire annunciator; and
    4. Master caution/warning annunciator.
  3. Instruments/indicators on the instrument panel in front of the left pilot seat. It has been found to be acceptable to relocate the torque indicator and/or the dual/triple tachometer to the left door/floor instrument cluster for rotorcraft that are flown single pilot from the LH seat for vertical reference operations only:

    1. Attitude indicator;
    2. Airspeed indicator;
    3. Low rotor RPM warning indicator;
    4. Fire warning indicator(s);
    5. Engine out indicator(s);
    6. Master Caution/Warning indicator(s);
    7. Altimeter; and
    8. NR/NPtachometer.
  4. Primary external load release is to be mounted on either the left cyclic grip or the left collective grip, and the secondary external load release is to be accessible to the pilot without releasing the primary flight controls. It has been found to be acceptable not to relocate system switches and controls for rotorcraft that are flown single pilot from the LH seat for vertical reference operations only. These rotorcraft must have a serviceable force trim system installed.
  5. Rotorcraft certified using the traditional certification approach, and which do not comply with all the certification requirements applicable to the modification must be certified as restricted category rotorcraft. The limitations appropriate to restricted category depend on the extent of the non-compliances, and specific guidance should be sought from the Aircraft Certification Flight Test division. Some typical limitations imposed in the past were:

    1. Occupants restricted to flight crew, flight crew under training, and individuals essential to the load being carried;
    2. No passengers;
    3. Flight over built-up areas prohibited; and
    4. LH seat single pilot operations authorized for vertical reference external load operations only.

5.2 Certification Requirements

  1. The following must be available within the pilot’s primary field of view at the outer surface of the door and approximately lined up with forward end of the collective for the pilot to be able to effectively fly the rotorcraft while performing vertical reference external load operations:

    1. NR/NP tachometer;
    2. Torque indicator;
    3. N1 indicator;
    4. T5 indicator;
    5. Master caution/warning indicator; and
    6. Fire warning indicator.
  2. The following flight instruments/indicators are required on the instrument panel in front of the PIC seat for the pilot to be able to effectively fly the rotorcraft from the LH seat when not in the hover mode:

    1. Attitude indicator;
    2. Airspeed indicator;
    3. RMI/DG/HSI;
    4. Low rotor RPM warning indicator;
    5. Fire warning indicator(s);
    6. Engine out indicator(s);
    7. Master Caution/Warning indicator(s);
    8. Altimeter;
    9. Vertical Speed indicator;
    10. NR/NP tachometer;
    11. Engine/Transmission torque indicator;
    12. Slip-skid indicator; and
    13. Various placards.
  3. Various system switches and controls must be relocated to the left cockpit to allow the pilot to continue to hold the cyclic with his right hand while performing normal, emergency and abnormal procedures. Examples of switches that may need to be relocated are:

    1. Engine Fuel Control mode switches;
    2. Engine Fire Extinguisher switches;
    3. Hydraulic shut-off switches;
    4. AFCS disconnect switches;
    5. Throttle stop switches;
    6. Engine Starter switches; and
    7. Fuel Shut-off switches.
  4. The primary external load release is to be mounted on either the left cyclic grip or the left collective grip and the secondary external load release is to be accessible to the pilot without releasing the primary flight controls.
  5. The pilot restraint harness configuration must be assessed to ensure it allows the pilot the amount of movement necessary to repeatedly perform the operation without undue discomfort or fatigue over an extended period of operation.

6.0 Certification Tests

6.1 Cockpit Evaluation

The location of all the instruments, switches, indicators and displays will be reviewed to ensure that the proposed cockpit design is usable for the intended operation using the minimum certified crew. This assessment will be performed under day and night conditions.

6.2 Normal Procedures

All the normal procedures and intended functions of the rotorcraft will be assessed using the minimum certified crew. This assessment will be performed under day and night conditions, if applicable, including all certified types of operation, such as VFR, IFR, and Category A as described in section 500.02 of the AWM. The intent is to verify that the minimum crew can operate the rotorcraft safely without any system failures.

6.3 Emergency Procedures

All the rotorcraft emergency/abnormal procedures will be assessed using the minimum certified crew. The scope of this assessment is not limited to single failures or published procedures, but may also include any failure, or combination of failures, that are not considered to be extremely improbable. The assessment will be performed under day and night conditions, if applicable, including all certified types of operation, such as VFR, IFR, and Category A. The intent is to verify that the minimum crew can operate the rotorcraft safely while coping with system failures.

7.0 Rotorcraft Flight Manual

7.1 Limitations

  1. Changes to the minimum certified crew complement, PIC seat, and the types of operation must be documented in the limitations section of the RFMS.
  2. Equipment requirements that allow the change to minimum crew complement, and PIC seat must be documented in the limitations section of the RFMS.
  3. Other limitations that are required due to the change in PIC seat and minimum crew complement must be included in the limitations section of the RFMS. Limitations that are required to restrict the approved operations of the rotorcraft will be imposed on rotorcraft certified in the restricted category due to non-compliance with some of the applicable regulations.

7.2 Normal Procedures

Changes to the normal procedures that are required due to the change in PIC seat and minimum crew complement must be included in the normal procedures section of the RFMS.

7.3 Emergency/Abnormal Procedures

Changes to the emergency/abnormal procedures that are required due to the change in PIC seat and minimum crew complement must be included in the emergency/abnormal procedures section(s) of the RFMS.

7.4 Performance

  1. Changes to the performance of the rotorcraft due to the change in PIC seat and minimum crew complement must be included in the performance section of the RFMS.
  2. If the N1 and T5 indicators are not reproduced in the door/floor instrument cluster, for vertical reference operations, then a procedure or performance information, or both, will have to be developed. This is to ensure that the pilot is aware of what torque corresponds to the first engine limit reached under the prevailing atmospheric conditions throughout the approved flight envelope.

8.0 Contact Office

For more information please contact:
Policy Standards Coordinator (AARDH/P)
Phone:             613-990-8234
Facsimile:         613-996-9178
E-mail:             AARDH-P@tc.gc.ca

Original signed by Gilles Morin:

Gilles Morin
Chief, Regulatory Standards
Aircraft Certification

Date modified: