Normal Operations Safety Survey – NOSS

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Normal Operations Safety Survey – NOSS

44TH ANNUAL CONFERENCE, Melbourne, Australia, 17-22 April 2005

WP No. 161

Normal Operations Safety Survey – NOSS

Presented by PLC


1.1. This subject was added to the PLC agenda for the year 2004-2005 by Committee C, after a very comprehensive presentation on the same subject made by IFATCA Human Factor Specialist (HFS), Bert Ruitenberg.

1.2. The provision for systemic safety in the aviation industry, present in the Airlines since 1990, has been recently introduced, by ICAO Annex 11, in ATM. Many Air Navigation Service Providers (ANSPs) are still in process of establishing a Safety Management System (SMS), where Airlines already possess experience with it. Airlines greater experience has made evident the need for a proactive approach to safety, able to bring even low level threats and errors to the attention of Safety Managers. A powerful tool in this direction is the “Line Operations Safety Audit” (LOSA), based on Threat and Error Management (TEM) model, developed by the University of Texas and endorsed by ICAO through its “LOSA Manual” Doc 9803. The strategy behind systematic line observations is aimed to provide safety data on functioning of an airline’s flight operations system and diagnostic indicators of organisational strengths/weaknesses in flight operations. Since LOSA has showed to be beneficial, ICAO is now exploring an equivalent tool for the ATM environment, the Normal Operation Safety Survey (NOSS).

1.3. NOSS is, as well as LOSA, a safety management tool based on TEM. It is aimed to capture operational context data during everyday routine operations and provides a TEM profile of the organisation, with data not available from conventional methods.

1.4. The discussion following HFS presentation outlined the importance IFATCA tributes to all systems, methods and tools aimed to improve safety, and its support to their introduction. At the same time, it outlined a series of concerns on the use, or misuse, of the data initially recorded within the SMS frame.


2.1. IFATCA has policy on SMS (Safety Management Systems). IFATCA Manual, page 4 1 7 1, states:


7.1. Introduction and Training Policy

7.1.1. IFATCA supports the introduction of Safety Management Systems (SMS) for the purpose of ensuring a systematic Approach to the reduction of risk within the ATM system.

7.1.2. ATM providers should be encouraged from the outset to utilise the available operational expertise already existing within their organisations when developing SMS.

7.1.3. ATM providers should make available training in safety related subjects such as hazard analysis and risk assessment for selected operational personnel to maximise the effectiveness of the SMS processes. (Geneva 01.C.1)


2.2. NOSS is a new concept under development by the ICAO NOSS Study-Group (IFATCA HFS is member of this study group), and will see its first operational trials during 2005 (by NavCanada, Airservices Australia and Airways Corporation New Zealand). It will be presented at the ICAO Global Conference Q4 2005. Derived from LOSA, it will be conducted by trained observers, present defined operating characteristics and represent a powerful tool for ANSP Safety Managers.

2.2.1. Trained observers will:

  • Record and code potential safety threats,
  • Record how these threats are addressed,
  • Record and code errors generated by these threats,
  • Record how these errors are managed.

2.2.2. NOSS Operating Characteristics are expected to be:

  • Over-the-shoulder observations during normal shifts (i.e. not in OJT situations),
  • Joint management/controller association sponsorship,
  • Voluntary participation,
  • De-identified, confidential, and non-disciplinary data collection,
  • Targeted observation instrument,
  • Trained and standardised observers,
  • Trusted data collection sites,
  • Data cleaning process,
  • Targets for safety enhancement,
  • Feedback results to the controllers.


3.1. IFATCA tributes a great importance to all systems, methods and tools aimed to improve safety, and supports their introduction. NOSS can provide an overview of most pertinent threats and errors for an organisation and it is considered to be an integral element of a mature safety management system.

Draft Recommendation

4.1. It is recommended that the following be inserted in the IFATCA Manual on page 4 1 7 1 as policy:

7.3 Normal Operations Safety Survey

7.3.1 Monitoring Safety in Normal Operations must be seen as an integral element of a Safety Management System.

7.3.2 A safety tool such as NOSS, shall meet following conditions:

  • Joint management/controller sponsorship;

  • Voluntary participation;

  • Trained observers;

  • Set targets of safety enhancements;

  • De-identified, confidential, and non-disciplinary data collection; and

  • Adequate feedback of the results to the controllers.


Monitoring Safety in Normal ATC Operations – Bert Ruitenberg – Hong Kong 2004.

TEM and NOSS in ATC, A Briefing for SISG/15 – Bert Ruitenberg – Nice, France, 10 November 2004.

Last Update: September 29, 2020  

December 21, 2019   933   Jean-Francois Lepage    2005    

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