Feasibility Study Rule Based Safety Target Groups

Feasibility Study Rule Based Safety Target Groups Targeting safety by operational rule part M. Campbell Safety Analyst Airworthiness Updated September 2004 DW1079719-0 Civil Aviation Authority

Table of Contents Introduction... 1 Background... 1 Summary... 1 Analysis... 2 Introduction... 2 The Proposal... 2 New Rule Structure... 2 STGs for the new rules... 2 Size of the new STGs... 3 Benefits and Drawbacks... 4 Aircraft Operations Statistics reporting (Form 605)... 4 AQD... 4 IT system... 5 Aircraft type records... 5 Required rule changes... 5 Non-Registered Aircraft... 5 Microlights and Gliders... 5 CTO... 6 ICAO reporting... 6 CAA Safety Reporting... 6 Conclusion... 7 Appendices... 8 Table 1 Proposed STG coverage of eisting STGs... 8 Epected activity in new STG s... 8 Table 2 Form 605 vs new STG structure... 9 Options which have been considered and rejected or not followed up... 10 24 September 2004 Page i

Introduction Background CAA Senior Management (SMT) met with the Safety Analysis Unit (SAU) on 26 November 1998 to determine the nature of safety outcome targets for the year 2005. The SMT and SAU agreed after the meeting that the SAU would investigate the possibility of the CAA using Safety Target Groups (STGs) based on the operational rules parts. This report has been updated in September 2004 as background information for the setting of Safety Targets for 2010. Summary STGs based on operational rule parts are feasible. The main advantage of rule based STGs is close identification of each safety target with the rule covering that type of operation. There are no major disadvantages. A system of 13 rule based STGs is proposed in this report. These STGs divide the industry by operational rule (Parts 91, 115 (proposed), 121, 125, 135, 137) and by aircraft type (fied wing, helicopter, other (for Part 115 commercial operations by non-registered aircraft such as hang gliders and parachutes)). A rule based system would require changes to etend eisting statistical reporting requirements to include: commercial transport commercial adventure aviation operations (including gliders and microlights on adventure aviation) under the proposed rule Part 115 non-registered aircraft flown on commercial adventure aviation activities by operators unde the proposed rule Part 115 (eg parachutes, paragliders and hang gliders). The CAA information system would require rewriting to implement rule based STGs. The Management Information Services (MIS) Manager estimated in 1999 that rewriting for rules based STGs would take 30 developer/days. He also estimated that the rewrite would take approimately 6 months elapsed time. The report envisages little etra compleity for most operators. Part 135 operators would have a requirement to report CTO and ATO operations separately if the proposed structure was implemented. Other eisting operators would have no additional requirements. The Technical Director for Superstructure Developments Ltd. believes changes to AQD to implement this system would be minor, and the upgrade would be covered by the annual maintenance charge which most users pay. The proposed system would not affect the eisting formats of CAA Safety Plan and Reports, or reports to ICAO. 24 September 2004 Page 1

Analysis Introduction This report presents a specific structure for rule based STGs. Having a structure makes it easier to visualise what the consequences, benefits and advantages of a rule based structure might be. There are other possible structures, and some of the options not adopted are discussed in the Appendices. Most of the comparison between the eisting and proposed structures would also be valid for any other rule-based system. The Proposal New Rule Structure There are 6 rules covering aircraft operations other than sport aviation. These are: Part 91 General operating and flight rules Part 115 Commercial Adventure Aviation. Part 115 is a proposed rule at this time, and this paper assumes that it, or something similar, will be created within the time frame being considered. Part 121 Air transport operations Large Aircraft Part 125 Air operations medium aircraft Part 135 Air transport operations small aircraft and helicopters Part 137 Agricultural aircraft operations. STGs for the new rules The proposed STGs, their populations and measures required are: STG Population Measures Part 121 Part 125 Part 135 ATO Fied Wing Air Transport operations by fied wing aircraft with 30 seats or more. Air Transport operations by fied wing aircraft with 10-29 seats. Air Transport operations by fied wing aircraft with less than 10 seats. Part 135 ATO Helicopter Air Transport operations by helicopters. Part 135 CTO Fied Wing Part 135 CTO Helicopter Commercial Transport operations by fied wing aircraft. Commercial Transport operations by helicopters. Part 137 Fied Wing Agricultural Operations by fied wing aircraft. hours Part 137 Helicopter Agricultural operations by helicopters. hours 24 September 2004 Page 2

STG Population Measures Part 115 Fied Wing Part 115 Helicopter Commercial adventure aviation operations by registered aircraft other than helicopters (includes gliders and microlights). Commercial adventure aviation operations by helicopters. Part 115 Other Adventure Aviation by non-registered aircraft. Part 91 Fied Wing Other hours flown by fied wing aircraft. hours Part 91 Helicopter Other hours flown by helicopters. hours The new STG structure was developed by: dividing all parts into separate groups for helicopter and fied wing operations, ecept for Parts 121 and 125, and further dividing Part 135 into groups for Commercial Transport and Air Transport Operations (CTO and ATO). The Part 115 group for unregistered aircraft is discussed later. All eisting STGs are covered by at least one new STG (see Table 1 in Appendices). Most STGs are for various types of smaller commercial/air transport operations, with 9 of the 13 covering this sector. The Adventure Aviation operations (AAO) groups and Agricultural operations groups account for 5 of these 9. The other 4 cover Part 135, and there are 2 groups each for private use and heavy/medium air transport. The overall effect is to give more detailed oversight of the small aircraft commercial operations. Size of the new STGs Part 91 Helicopter (private operations) is epected to have a low level of activity. This may lead to highly variable accident rates from year to year, but this group is eactly the same as the current Helicopter non-revenue group, so there is no change epected to be required. There is no means of estimating the activity levels for the Part 115 groups. It is assumed they will have relatively low hours, but may have considerable numbers of flights, since activities such as bungy jumping and eternal human loads are usually short duration flights. It may be more appropriate that the targets for these STGs are epressed per flight rather than per hour. The means of estimation and activity estimated are given in the appendi. 24 September 2004 Page 3

Benefits and Drawbacks The eisting system and proposed rule based system have a number of advantages and disadvantages compared to each other: Advantages Disadvantages Retaining current system Is familiar, and has already been negotiated with Industry. Provides a continuous record of aviation activity to the present day. Most STGs do not identify the rule(s) appropriate to them. Does not include new types of operation (CTO, AAO) requires etensive changes to incorporate. Cannot record commercial operations by non-registered aircraft requires etensive changes to incorporate. Adopting rule-based system Operating rules and safety targets are directly linked. Provides more detailed picture of commercial operations involving small aircraft. Breaks the continuity of record, although a limited comparison with eisting system is possible. Some STGs have low activity, so are likely to have highly variable accident rates. Software will require 30 developer/days to write. Aircraft Operations Statistics reporting (Form 605) Form 605 will soon be inadequate for recording aviation statistics regardless whether rulebased STGs are adopted or not. It does not have any provision for recording either CTO or AAO, nor can it record commercial activities carried out by non-registered aircraft such as hang gliders and parachutes. Both scheduled and unscheduled CTO will need to be recorded. Scheduled CTO and Unscheduled CTO will each require lines for A-A, A-B and Freight only operations. This will allow easier comparison of ASMS data with that from overseas authorities, who usually make a distinction between scheduled and unscheduled operations. AAO will require a new line on the form. The eisting Other Revenue: Other line is meaningless in the new rule structure, so must be redefined or replaced. AQD Changes to Form 605 will require matching changes to AQD. This was discussed briefly with the Technical Director of Superstructure Developments Ltd., who believed that the changes to AQD would be fairly simple to make. Customers paying the annual service charge would receive an updated version at no etra cost. 24 September 2004 Page 4

IT system IT developers and management advised me that the changes required to implement this proposal were feasible. The MIS Manager estimated that 30 developer/days will be required for analysis and consultation. Development would take approimately 6 months elapsed time. Aircraft type records The proposal requires that the certified seating capacity of each aircraft be recorded on ASMS. CAA MIS automatically sorts aircraft into the correct STGs by using the aircraft type and weight from the aircraft file. The new STGs will be created in a similar manner, using the number of seats and aircraft type from the aircraft file. The CAA database has provision for recording the certified number of seats for each aircraft type in the AC Aircraft Model Manufacturer table, but entering the data is currently optional. Completing this field must become compulsory when a first of type is certified to ensure the system will assign the aircraft s data to the proper STG. The seating capacity is to be that recorded on the Type Certificate Data Sheet or equivalent, as this is the criteria for determining which operational rule the aircraft falls under for air transport. The Manager Aircraft Certification agreed that this is desirable, and most eisting aircraft types have had this field completed. Required rule changes Several rule changes would be required for this proposal to be implemented. Non-Registered Aircraft The proposal includes a STG for non-registered aircraft carrying out Adventure Aviation operations (AAO), such as hang gliders, paragliders and parachutes. Recording the activities of these aircraft would be achieved by a change to Rule Part 12, to require Part 115 certificate holders to report their operations statistics as a single block. These aircraft would have a separate STG - Part 115 Other. It is assumed that it is desirable to record statistics for these aircraft because they will be carrying out a commercial operation. They would be required to report both flights and hours, as do other commercial operations. The eisting system has no provision for recording operational statistics for these aircraft. Microlights and Gliders Rule 12 currently eempts Microlights and Gliders from the reporting requirements: microlights because they do not hold standard or restricted airworthiness certificates (refer 12.151(a)), and gliders per 12.151(c). Rule 12 would require a change to require all aircraft involved in AAO to report the number of flights and hours flown, regardless of type. 24 September 2004 Page 5

CTO CTO flights will be recorded in addition to the number of hours. This will require a change to Rule 12.151 (a)(3) to include CTO operations. ICAO reporting The eisting format for reports to ICAO can be maintained with the proposed system. CAA Safety Reporting The eisting si-monthly Safety Report format can be retained under this proposal, with aircraft divided by weight break for reporting purposes. The proposal would allow a change to rule based divisions, if that is found to be desirable at some time in the future. 24 September 2004 Page 6

Conclusion STGs based on operational rule parts are feasible. The main advantage of rule based STGs is close identification of each safety target with the rule covering that type of operation. There are no major disadvantages. The reporting requirements for Part 135 operators would become more comple because of the requirement to report CTO and ATO operations separately. Other operators would have no additional requirements and it is considered that the overall increase in compleity to be minimal. A rule based system would require changes to etend eisting statistical reporting requirements to include: commercial transport commercial adventure aviation operations (including gliders and microlights on adventure aviation) non-registered aircraft flown on commercial adventure aviation activities by Part 115 certificate holders (eg parachutes, paragliders and hang gliders). The CAA information system would require rewriting to implement rule based STGs. The MIS Manager estimated in 1999 that rewriting for rules based STGs would take 30 developer/days. He also estimated that the rewrite would take approimately 6 months elapsed time. 24 September 2004 Page 7

Appendices Table 1 Proposed STG coverage of eisting STGs (F = Fied wing, H = Helicopter, O = Other) New Group: 91 115 121 125 135 ATO 135 CTO 137 F H F H O F H F H F H Eisting group: 13608 kg and above 5,670 to 13,608 kg 2,721 to 5,670 kg Below 2,721 kg rev pa & freight Below 2,721 kg rev other Below 2,721 kg non rev Heli rev pa & freight Heli rev other Heli non rev All eisting STGs are covered by 1 or more of the proposed STGs. Epected activity in new STG s An approimate activity level has been estimated for each of the proposed STGs based on simple analysis of the 2003 operating statistics: 121 220,000 hours (Air transport 13,608 kg and above) 125 105,000 hours (Air transport 5,670 to 13,608 kg) 135 ATO Fied Wing 50,000 hours (Pa & Frt, Below 5,670 kg) 135 ATO Helicopter 36,000 hours (Scheduled air transport helicopter) 135 CTO Fied Wing 180,000 hours (Aerial work other than Ag, Below 5,670 kg) 135 CTO Helicopter 70,000 hours (Aerial work other than Ag, helicopter) 137 Fied Wing 55,000 hours (Agricultural, all fied wing) 137 Helicopter 40,000 hours (Agricultural helicopter) 115 Fied Wing unknown 115 Helicopter unknown 115 Other unknown 91 Fied Wing 47,000 hours (All other fied wing) 91 Helicopter 7,500 hours (All other helicopter). 24 September 2004 Page 8

Table 2 Form 605 vs new STG structure Proposed rule part: 91 115 121 125 135 135 137 CTO ATO Form 605 operation type: Air transport international Pa Freight Air transport dom sched A-B A-A Freight Air transport dom unsched A-B A-A Freight Other revenue Agricultural Other Training/instruction Dual Solo Non-revenue Business/eecutive Test & ferry Other private The eisting format for Form 605 cannot differentiate between Part 135 ATO and Part 135 CTO, since both include part of the eisting Air Transport category. 24 September 2004 Page 9

Options which have been considered and rejected or not followed up A number of features were considered for the proposal but not included: Record Part 115 statistics by activity type, eg bungy jumping, rappelling, etc. Not fully considered yet. This would provide more detailed information on Part 115 activities, at the epense of etra complication on the reporting form and for the operator. This option should be more fully considered if the SMT decides to proceed with rule based STGs. Combine Part 135 CTO with Part 135 ATO into 2 generic Part 135 STGs, one for fied wing and one for helicopter. The difference between ATO and CTO is roughly comparable to the current difference between revenue passenger and freight and revenue other. Ii is believed this is a desirable difference to retain, as it allows the safety performance of the two types of operation to be assessed separately. Include a Part 133 STG, Helicopter Sling Loads. Part 133 is not a general flight or certification rule. Operations under 133 will also be under one of the general or certification rules included, so will be recorded under the appropriate flight rule. A Part 133 STG would probably have had a low level of activity, and would have weakened other STGs by reducing the activity recorded in them. Obtain operating statistics of non-registered aircraft by requiring the aircraft to be registered, or by requiring the pilots to report. It is assumed that registering nonregistered aircraft would be an unwanted complication, and that requiring pilots to report would prove unreliable as a data source. 24 September 2004 Page 10