(1) This Chapter applies only for RPA operations of a certified RPA operator.
(2) Only a certified RPA operator may be granted an approval under paragraph 101.029 (2) (b) of CASR:
(a) for subparagraph 101.300 (4) (b) (i) — to operate an unmanned aircraft beyond the operator’s visual line of sight; or
(b) for subparagraph 101.300 (4) (b) (ii) — for a RePL holder who is a member of the operator’s personnel to operate an unmanned aircraft beyond the RePL holder’s visual line of sight.
Note An approval would be granted to the certified RPA operator only if the requirements of Chapter 5 are met — see paragraph 101.029 (2) (b) of CASR.
(3) Only a RePL holder:
(a) who is a certified RPA operator holding an approval for paragraph (2) (a); or
(b) who is a member of the personnel of a certified RPA operator holding an approval for paragraph (2) (b);
may be granted an approval under paragraph 101.029 (2) (b) of CASR for subregulation 101.073 (2) to operate an unmanned aircraft beyond the RePL holder’s visual line of sight.
Note An approval for a RePL holder would only be granted in association with the grant of a relevant approval for a certified RPA operator.
5.02 Requirements for RPA operations do not apply in certain approved areas
(1) Subject to subsection (2), this Chapter applies to any area that is an area approved by CASA for regulation 101.030 of CASR.
(2) This Chapter does not apply to an EVLOS operation if the area approval permits an EVLOS operation that is in accordance with alternative requirements specified in the approval.
5.03 Requirements for an approval to operate an RPA beyond VLOS
(1) For paragraph 101.073 (2) (a) of CASR, this Chapter prescribes the requirements for the grant of an approval by CASA under paragraph 101.029 (2) (b) of CASR (an approval), for a person to operate an RPA, other than a large RPA, beyond the person’s VLOS.
Note See also paragraph 101.300 (4) (b) of CASR.
(2) In this Chapter, the approval mentioned in subsection (1) is referred to as:
(a) an EVLOS operation approval; or
(b) an EVLOS operation class 1 approval; or
(c) an EVLOS operation class 2 approval.
(3) For the grant of an approval, the Certified RPA operator’s documented practices and procedures must:
(a) provide for the matters mentioned in this Chapter; and
(b) be in accordance with the requirements of this Chapter; and
(c) ensure that RPA operations are conducted in accordance with the approval.
5.04 Definitions for this Chapter
EVLOS means extended visual line of sight.
EVLOS operation class 1 means an RPA operation that is beyond VLOS, and in which:
(a) at least 1 trained visual observer class 1 (the observer) is used; and
(b) the location of the RPA, and the ground beneath and the airspace surrounding, the RPA, is:
(i) located within VLOS for each relevant observer throughout the operation; or
(ii) beyond VLOS but with the relevant observer knowing the exact location of the RPA; and
(c) the observer is in the same location as the remote pilot; and
(d) an FPV system may be used, but not as a substitute for any observer; and
(e) the observer’s duty is to:
(i) either:
(A) keep the RPA constantly within VLOS; or
(B) know the exact location of the RPA; and
(ii) maintain constant situational awareness of the airspace surrounding, and the ground below, the RPA; and
(iii) remain in continual, direct, verbal communication with the remote pilot without the use of any device; and
(iv) do the following:
(A) advise the remote pilot if the RPA is likely to become a hazard to any other aircraft, or any person or property;
(B) direct the remote pilot on the action required to ensure that the RPA does not become a hazard to another aircraft, person or property;
(C) immediately direct the safe termination of the operation if:
(I) the exact location of the RPA is lost to the relevant observer’s direct sight or knowledge; or
(II) the RPA becomes a hazard to another aircraft, person or property and termination of the operation is the only safe course of action.
Note 1 A flight may be ended by means of controlled flight into terrain, if this is possible without creating a hazard to other aircraft, people or property, and all other options are exhausted.
Note 2 An EVLOS operation extends the distance of operation of an RPA. However, by virtue of the definition, the remote pilot, while operating the RPA using FPV, cannot be the observer for an EVLOS class 1 operation.
EVLOS operation class 2 means an RPA operation that is beyond VLOS in which:
(a) at least 1 trained visual observer class 2 (the observer) is used; and
(b) the RPA, and the ground beneath and the airspace surrounding the RPA, is:
(i) located within VLOS for each relevant observer throughout the operation; or
(ii) beyond VLOS but with the relevant observer knowing the exact location of the RPA; and
(c) the observer is in a different location from the remote pilot; and
(d) an FPV system may be used, but not as a substitute for any observer; and
(e) the observer’s duty is to:
(i) either:
(A) keep the RPA constantly within VLOS; or
(B) know the exact location of the RPA; and
(ii) maintain constant situational awareness of the air space surrounding, and the ground below, the RPA operation; and
(iii) remain in continual direct, verbal communication with the remote pilot using an effective communication system; and
Note The system must use reliable modern technology that enables effective spoken communication.
(iv) do the following:
(A) advise the remote pilot if the RPA is likely to become a hazard to any other aircraft, or any person or property;
(B) direct the remote pilot on the action required to ensure that the RPA operation does not become a hazard to another aircraft, person or property;
(C) immediately direct the safe termination of the operation if:
(I) the exact location of the RPA is lost to the relevant observer’s direct sight or knowledge; or
(II) the RPA becomes a hazard to another aircraft, person or property and termination of the operation is the only safe course of action.
Note 1 A flight may be ended by means of controlled flight into terrain, if this is possible without creating a hazard to other aircraft, people or property, and all other options are exhausted.
Note 2 An EVLOS operation extends the distance of operation of an RPA. By virtue of the definition, the remote pilot may be the initial EVLOS class 2 observer provided that the remote pilot is not simultaneously using an FPV system.
EVLOS operation means:
(a) an EVLOS operation class 1; or
(b) an EVLOS operation class 2.
first person view system is a system that:
(a) uses a camera on an RPA to produce a video display of the flight as it would be seen if a pilot were notionally on board the RPA in order to assist the remote pilot to navigate, orient, and avoid obstacles to the RPA; and
(b) is sufficiently powerful, sensitive and robust to remain effective for the duration of the EVLOS operation; and
(c) is approved by CASA for the EVLOS operation.
Note Use of an FPV may assist a remote pilot but its use cannot transform the remote pilot into an observer for an EVLOS operation. A remote pilot cannot simultaneously use an FPV and be an observer.
FPV system means first person view system.
observer means:
(a) a trained visual observer class 1; or
(b) a trained visual observer class 2.
trained visual observer class 1 means a person who has been:
(a) trained by a certified RPA operator, in accordance with the requirements in its documented practices and procedures, to observe and communicate about an RPA in an EVLOS operation class 1; and
(b) certified by the RPA operator to have successfully completed the training in accordance with the documented practices and procedures.
trained visual observer class 2 means a person who has been:
(a) trained by a certified RPA operator, in accordance with the requirements in its documented practices and procedures, to observe, and communicate about, an RPA in an EVLOS operation class 1 or class 2; and
(b) certified by the RPA operator to have successfully completed the training in accordance with the documented practices and procedures.
VLOS means visual line of sight.
5.05 Documented practices and procedures for EVLOS operations
For an EVLOS operation approval, a certified RPA operator must have documented practices and procedures containing the following:
(a) for each matter, activity or requirement mentioned in this Chapter — procedures and requirements that comply with this Chapter;
(b) the operator’s statement to its remote pilots and observers that the procedures and requirements for relevant operations must be complied with.
Note See also the definition of documented practices and procedures in subsection 1.04 (2) which requires documented practices and procedures to be approved by CASA.
5.06 Remote pilots for EVLOS operations
Before conducting an EVLOS operation, the remote pilot:
(a) must have completed, in addition to the 5 hours’ experience required under paragraph 101.295 (2) (c) of CASR, at least the number of hours of flight time, as relevantly specified in the operator’s documented practices and procedures, operating in VLOS operations an RPA of the same type as the RPA that is to be used in the EVLOS operation; and
(b) must have been trained and certified by the RPA operator, in accordance with its documented practices and procedures, as competent to carry out the particular EVLOS operation; and
(c) must have successfully completed a proficiency check that was:
(i) conducted by:
(A) the chief remote pilot of the certified RPA operator; or
(B) a RePL holder of the certified RPA operator who is:
(I) is authorised under the operator’s ReOC to conduct the relevant proficiency check; and
(II) approved in writing for the purpose by the operator’s chief remote pilot; or
(C) CASA; and
(ii) undertaken not more than:
(A) 12 months before the EVLOS operation; or
(B) 24 months before the EVLOS operation, provided the remote pilot has completed at least 3 EVLOS flights in each of the 12-month periods before the EVLOS operation; and
(iii) carried out in accordance with the relevant certified RPA operator’s documented practices and procedures for proficiency checks under this section.
Note Under subregulation 101.300 (4), a RePL is subject to the condition that an RPA must be operated within VLOS unless the licence holder has met certain requirements set out in that subregulation.
5.07 Observers for EVLOS operations
(1) An EVLOS operation class 1 may only be conducted using a trained visual observer class 1 or class 2, certified by the RPA operator as competent to carry out the particular EVLOS operation in accordance with the documented practices and procedures.
(2) An EVLOS operation class 2 may only be conducted using a trained visual observer class 2, certified by the RPA operator as competent to carry out the particular EVLOS operation in accordance with the documented practices and procedures.
(3) An observer for subsection (1) or (2) must have no duties during the operation of an RPA, other than those mentioned in paragraph (e) of the definition of EVLOS operation class 1 or EVLOS operation class 2, as the case requires.
(4) An observer for subsection (1) or (2) must not be required to observe more than 1 RPA for more than 1 remote pilot in any EVLOS operation unless the operation is:
(a) approved in writing by CASA; and
(b) operated in accordance with any conditions of the approval.
(5) An observer for subsection (1) or (2) may use a device, for example, binoculars or a telescope, to assist in carrying out their duties, but must not use the device as the primary means of keeping the surrounding airspace and ground in sight.
(6) For subsection (4), the duties mentioned in paragraph (e) of the definition of EVLOS operation class 1 or EVLOS operation class 2 are to be read as also referring to more than 1 RPA or more than 1 remote pilot, as the case requires.
5.08 Handover procedures between 1 remote pilot and another remote pilot for EVLOS operations
(1) Control of an RPA must not be transferred (handed over) from the remote pilot (the handing-over remote pilot) to another person (the new remote pilot) unless:
(a) the other person is also a remote pilot who complies with section 5.06; and
(b) the handover is in accordance with the certified RPA operator’s documented practices and procedures.
(2) After a handover occurs, the new remote pilot is:
(a) the remote pilot of the RPA; and
(b) responsible and accountable for ensuring that the EVLOS operation complies with all requirements of the relevant civil aviation legislation as if the operation were first commencing from the time, date and location at which the new remote pilot assumes control of the RPA.
5.09 Pre-flight briefing for an EVLOS operation
The certified RPA operator must ensure that each remote pilot and each observer who is to be involved in an EVLOS operation is briefed, before the operation commences, on the emergency and collision avoidance procedures relevant to the operation.
5.10 Communications in an EVLOS operation class 2
For an EVLOS operation class 2, the communication system (the primary communication system) used by the remote pilot and each observer must be supported by an alternative or backup communication system (the secondary communication system) that can be immediately activated if the primary communication system fails.
5.11 Control and communication links must be maintained in an EVLOS operation
(1) In an EVLOS operation, an RPA may only be flown:
(a) while the control link performance from the remote pilot station to the RPA is reliably and consistently maintained; and
(b) while the communication link between the remote pilot and a relevant observer is maintained; and
(c) at a distance from the relevant observer that is the lesser of the following:
(i) 1 500 m;
(ii) the distance at which the relevant observer is able to perform all of their duties.
Note 1 The duties of a relevant observer are set out in paragraph (e) of the definition of EVLOS operation class 1, or paragraph (e) of the definition of EVLOS operation class 2, as applicable.
Note 2 For a CASA approval under subsection 5.03 (3), the operator’s practices and procedures would be assessed to determine how aviation safety margins were to be maintained and monitored; and whether reliable procedures were in place capable of identifying and addressing any degradation in control or communication links.
(2) An RPA operator who, immediately before the commencement of this section held an approval under section 5.03 for an EVLOS operation, may continue to operate the relevant RPA under the approval as if it continued in force for the duration of the approval (unless it is otherwise revoked by CASA).
5.12 Weather and visibility conditions for an EVLOS operation
(1) An RPA may only be flown in an EVLOS operation:
(a) if the remote pilot, and any observer, each has visual acuity (including when corrected) that complies with the Austroads standard for private motor vehicle licensing visual acuity, as in force from time to time; and
(b) in conditions with a visibility minimum of 5 000 m.
(2) If, during an operation, visibility falls below 5 000 m, the EVLOS operation must be terminated and the RPA landed, as soon as safely possible.
5.13 Controlled airspace and EVLOS operations
An approval of an EVLOS operation conducted in controlled airspace applies only if the operation is conducted in accordance with:
(a) the requirements of Part 101 of CASR and of this MOS; and
Note See, for example, Chapter 4 of this MOS and regulations 101.070, 101.072 and 101.075 of CASR.
(b) any other conditions in any approval from CASA, and any permission from the air traffic control service for the aerodrome, for operations in the relevant controlled airspace.
5.14 Night EVLOS operations
For an approval of an EVLOS operation to be conducted at night, the certified RPA operator must:
(a) be approved for night RPA operations under instrument CASA 01/17, or any replacement instrument in force from time to time unless the replacement instrument expressly applies otherwise; and
(b) satisfy CASA that they can and will comply with the conditions of the instrument.
Note Chapter 6 of this MOS is reserved for more general requirements relating to night operations.
5.15 If manned aircraft are active in the airspace
(1) If, during an EVLOS operation, a manned aircraft is:
(a) flying in the relevant airspace of the operation (the relevant airspace); or
(b) likely to be flying in the relevant airspace;
then, the remote pilot for the EVLOS operation must ensure that the operation does not become a hazard to the manned aircraft, by using, or, subject to subsection (1A), by directing a certified and appropriately trained visual observer to use, the relevant aeronautical VHF channel for:
(c) regular broadcasts; or
(d) direct radiocommunication with the pilot of the manned aircraft.
(1A) Despite a direction given under subsection (1), the remote pilot for the EVLOS operation is at all times responsible for ensuring that the operation of the RPA complies with regulation 101.055 — Hazardous operation prohibited.
(2) Without affecting subsection (1), a person who is a remote pilot for the EVLOS operation must take reasonable steps to make and keep in direct radiocommunication with the pilot of a manned aircraft while the RPA and the manned aircraft are in relevant airspace.
(3) In this section:
relevant airspace means any point of non-controlled airspace into which the manned aircraft is flying at a particular time that is both less than 3 NM in distance and less than 1 500 ft in height from any point of the airspace in which the RPA is flying at the same time.
5.16 Procedures for loss of control of an RPA in an EVLOS operation
(1) For an RPA in an EVLOS operation, the certified RPA operator’s documented practices and procedures must have procedures for the remote pilot to resolve a loss of control over the RPA.
(2) For subsection (1), the procedures must be such as to ensure that the remote pilot can:
(a) re-establish control over the RPA; or
(b) end the flight without creating an unreasonable hazard to another aircraft, or to people or property.
Note A flight may be ended by means of controlled flight into terrain, if this is possible without creating a hazard to other aircraft, people or property, and all other options for the continuation of safe, observed, flight are exhausted.
5.17 Procedures for loss of communications in an EVLOS operation class 2
(1) For an RPA in an EVLOS operation class 2, the certified RPA operator’s documented practices and procedures must have procedures for the remote pilot to resolve:
(a) any communication system failure relating to the observation of the RPA; or
(b) any breakdown in communication procedures relating to the observation of the RPA; or
(c) any loss of situational awareness by the relevant observer of the RPA for any reason.
(2) For subsection (1), the procedures must be such as to ensure that the remote pilot must:
(a) for a loss of communications with an observer — immediately use the secondary communication system; or
(b) for a loss of situational awareness by the relevant observer — immediately implement the certified RPA operator’s procedures for loss of situational awareness by an observer to return the RPA to VLOS or EVLOS; or
(c) end the flight without creating an unreasonable hazard to another aircraft, or to people or property.
Note A flight may be ended by means of controlled flight into terrain, if this is possible without creating a hazard to other aircraft, people or property, and all other options for the continuation of safe flight are exhausted.
5.18 Conflict between the requirements of this Chapter and the documented practices and procedures
(1) A certified RPA operator must ensure that there is no conflict or inconsistency between the requirements of this Chapter and the documented practices and procedures.
(2) If there is any conflict or inconsistency:
(a) the requirements of this Chapter must prevail; and
(b) the documented practices and procedures must be immediately revised and corrected.
Note See also the definition of documented practices and procedures in subsection 1.04 (2) of this MOS which requires documented practices and procedures to be approved by CASA.
CHAPTER 6 RESERVED
CHAPTER 7 RESERVED
CHAPTER 8 RESERVED
CHAPTER 9 OPERATIONS OF RPA IN PRESCRIBED AREAS
Division 9.1 RPAS operations at or near non-controlled aerodromes
9.01 Prescribed areas
(1) For regulation 101.066 of CASR, this Division prescribes the requirements relating to the operation of an RPA or a model aircraft in a prescribed area.
(2) For subsection (1), the no-fly zone of a non-controlled aerodrome is a prescribed area for this Division.
9.02 Definitions
In this Division:
area that is shaded black has the same meaning as in section 9.06.
area that is shaded grey has the same meaning as in section 9.06.
defined unmanned aircraft means any of the following:
(b) an unmanned aircraft operated in accordance with an authorisation (however called) or exemption, granted under CASR, that permits operation of the aircraft within the no-fly zone of a non-controlled aerodrome during a relevant event;
(c) an unmanned aircraft operated in accordance with an approval of an approved area under regulation 101.030 of CASR.
no-fly zone of an HLS means the area and airspace that is a cylinder:
(a) whose centre is the centre of the HLS; and
(b) which has a radius of 0.75 NM; and
(c) which has a vertical height of 400 ft.
no-fly zone of a non-controlled aerodrome means any areas and airspace that are:
(a) within 3 NM, in any direction, from the measurement point of any runway of the non-controlled aerodrome; or
(b) within the approach and departure paths referred to in section 9.06, whether or not they extend beyond 3 NM, in any direction, from the measurement point of any runway of the non-controlled aerodrome.
Note If the runway is a grass landing strip, the threshold centrepoint of the runway is the point on the threshold of the runway at which the notional centreline of the runway would intersect the threshold.
relevant airspace means each of the following:
(a) the no-fly zone of a non-controlled aerodrome;
(b) the no-fly zone of an HLS.
relevant event means that a manned aircraft is within relevant airspace, including when the aircraft is in the course of approaching, landing at, taking off from, or manoeuvring on the movement area of, the aerodrome.
9.02A Meaning of to become aware
In sections 9.03 and 9.04, to become aware that a relevant event is occurring, or is about to occur, is taken to mean the state of awareness that a reasonable person would have, in all the circumstances, that the relevant event was occurring, or was about to occur.
9.03 RPA flight in the no-fly zone of a non-controlled aerodrome
(1) A person may fly an RPA or a model aircraft, or conduct RPA operations, in relevant airspace provided that:
(a) the flight or operation does not occur during a relevant event; and
(b) if, during the flight or operation, the person becomes aware that a relevant event is occurring, or is about to occur — the person complies with section 9.04.
Note A remote pilot with a relevant radio qualification should monitor the aerodrome radio frequency and communicate with manned aircraft using the aerodrome frequency.
(2) Despite subsection (1), a certified RPA operator may conduct RPA operations in relevant airspace during a relevant event, but only if the RPA operation is exclusively:
(a) an indoors operation; or
(b) a tethered operation in accordance with section 9.05; or
(c) an operation using a defined unmanned aircraft; or
(d) an operation using a micro RPA.
Note A person must not operate an unmanned aircraft in such a manner as to create an obstruction to an aircraft taking off from, or approaching for landing at, a landing area or a runway of an aerodrome – see subregulation 101.075 (4) of CASR.
(3) Despite subsection (1), a person may fly an RPA or model aircraft in relevant airspace during a relevant event, but only if the flight is:
(a) an indoors operation; or
(b) both:
(i) the operation of a micro RPA, or a model aircraft that has a gross weight of not more than 250 g; and
(ii) outside the movement area, and the approach and departure paths referred to in section 9.06; or
(c) an operation using a defined unmanned aircraft.
Note See also regulation 101.075 of CASR for offences in relation to operations near aerodromes.
9.04 Action on becoming aware of a relevant event
(1) If the person who is flying an RPA or model aircraft within relevant airspace becomes aware that a relevant event is occurring, or is about to occur, the person must:
(a) if the RPA or model aircraft is airborne:
(i) act immediately to ensure that the RPA or model aircraft is safely manoeuvred away from the path of the manned aircraft; and
(ii) land the RPA or model aircraft as soon as safely possible; or
(b) if the RPA or model aircraft is on the ground, on water, or on any object or structure on the ground or water — not launch the unmanned aircraft.
(2) To avoid doubt, this section does not apply to an operation mentioned in subsection 9.03 (2) or (3).
9.05 Approval to operate an RPA in a no-fly zone of a non-controlled aerodrome — tethered operations
(3) For a tethered operation in the no-fly zone of a non-controlled aerodrome, the certified RPA operator must:
(a) use a tether that is no longer than 150 ft; and
(b) ensure that the RPA is not operated higher than 150 ft above the aerodrome elevation; and
Note The aerodrome elevation can be determined from the aerodrome obstacle limitation data (OLS data).
(c) conduct the tethered operation in accordance with the operator’s documented practices and procedures for operations under this Division; and
(d) ensure that:
(i) the RPA is flown within the area that is shaded grey for the non-controlled aerodrome; or
(ii) if the RPA is flown within the area that is shaded black for the non-controlled aerodrome, the RPA is not flown within 3 NM from the measurement point of any runway of the non-controlled aerodrome.
(4) For paragraph (2) (b), the requirements for the no-fly zone of an HLS are as follows:
(a) the tether must be no longer than 150 ft;
(b) the RPA must always be at least 465 m from the central axis of the no-fly zone of the HLS;
(c) the RPA flight must be conducted within VLOS;
(d) the RPA flight must be conducted in accordance with the certified RPA operator’s documented practices and procedures for operations under this Division.
9.06 Approach and departure paths — non-controlled aerodromes
(1) Figure 9.06 (1)-1 shows the approach and departure paths of a non-controlled aerodrome.
Note Figure 9.06 (1)-2 illustrates a cross-runways scenario to which the requirements in this Division apply in the same way as for a single runway. Application of the requirements does not affect the black-shaded areas but produces overlapping grey-shaded areas, and what would otherwise be a grey-shaded area becomes a black-shaded area because of the intersection of the runways.
(2) As shown in Figure 9.06 (1)-1, the approach and departure path is up to 400 ft, as follows:
(a) anywhere on or from the ground upwards in the area that is the runway or the runway strip;
(b) anywhere in the following areas which are the approach and departure paths for the non-controlled aerodrome:
(i) on or from the ground upwards in the area that is shaded black to a distance of 7 km from the end of the runway strip;
(ii) anywhere from 150 ft (45 m) above the ground (referenced to the aerodrome elevation) in the area that is shaded grey.
(3) The area that is shaded black, which shows the approach and departure paths and the ground below them, is described as comprising the following:
(a) a symmetrical trapezoids with the shorter side coincident with the ends of a nominal 100 m wide runway strip and extending out at an angle of 15 degrees on either side to a distance of 7 km;
(b) a rectangle extending 500 m on either side of the runway centreline and overlying the runway strip until it intersects the trapezoids of the approach and departure paths.
(4) The area that is shaded grey is an area that extends 3 NM in all directions from the measurement point.
Non-controlled aerodromes approach and departure paths (shows matters, but shape only illustrates matters)
Figure 9.06 (1)-1 Non-controlled aerodromes approach and departure paths (shows matters, but shape only illustrates matters)
configuration of an RPA mentioned in this Chapter is comprised of the particular RPA’s airframe, engines and motors, and all of the flight control system hardware for the RPA.
Note The configuration of an RPA for its unique identification mark does not include propellers, rotors or batteries.
medium excluded RPA means an RPA within the meaning of subregulation 101.237 (7) of CASR.
Note A medium RPA (that is not an airship) has a gross weight of at least 25 kg but less than 150 kg.
operation, for an RPA, means a single flight of the RPA, or a series of similar or related flights of the RPA on the same day.
record includes an electronic record but only when:
(a) the electronic record is created in a form that makes the record unalterable after the record has been made; and
(b) if an erroneous electronic record is created — the correction of the electronic record is in the form of an electronic record which identifies the error and corrects it.
small excluded RPA means an RPA within the meaning of subregulation 101.237 (4) of CASR.
Note A small RPA has a gross weight of at least 2 kg but less than 25 kg.
unique identification mark, for an RPAS for an RPA mentioned in this Chapter, is the number (and letters, if any) that the certified RPA operator or other operator, as the case may be, ascribes to each configuration of the RPA that the particular operator operates.