(effective 2020/12/09)
Sections 1, 2 and 3 of this appendix specify the minimum assurance requirements and sections 4 and 5 the minimum performance specifications for the HOTDS.
(effective 2020/12/09)
1. Quality Management System
- 1.1 The Air Operator shall ensure that the service provider or manufacturer, establish, document, implement and maintain a quality management system that comprises procedures, processes and resources necessary to provide for the quality management of the HOTDS and reports to be supplied.
- 1.2 The quality management system required by Subsection 1.1 shall at a minimum:
- a) establish and maintain operational manuals and documentation;
- b) establish and maintain system commissioning protocols;
- c) establish and maintain system inspection requirements and methods;
- d) establish quality control and quality monitoring to include software integrity and data dissemination;
- e) specify qualifications and training requirements for personnel who commission, inspect or maintain the system, and
- f) ensure that action is initiated to determine and correct the cause if non-conformance is identified.
- 1.3 The documentation in Subsection 1.2 shall be made available to the Minister, upon reasonable notice by the Minister.
(effective 2020/12/09)
2. Training and Qualifications
- 2.1 The Air Operator shall ensure and document that the manufacturer or service provider maintains records to demonstrate that all persons providing installation, commissioning, inspection and maintenance services of a HOTDS are qualified persons who have received appropriate training and have demonstrated sufficient knowledge, skills and competence to perform their assigned duties.
- 2.2 The Air Operator shall ensure and document that the manufacturer or service provider has specified the minimum training requirements applicable to persons engaged in inspection and maintenance services of a HOTDS.
- 2.3 The Air Operator shall make a copy of the documentation referenced in 2.1 and 2.2 available to the Minister, upon reasonable notice by the Minister.
(effective 2020/12/09)
3. Installation, Siting, Operation & Maintenance of HOTDS
- 3.1 The Air Operator shall ensure that the service provider or manufacturer as applicable has established and followed practices, procedures and specifications for the siting, installation, commissioning, operation and maintenance of the HOTDS, including the co-ordination of activities with the aerodrome operator.
Note: Specifications concerning the siting and installation of equipment on aerodromes are contained in TP 312, Aerodrome Standards and Recommended Practices.
- 3.2 The input instruments shall be sited in sufficient proximity of each other to provide coherent sampling of meteorological inputs for holdover time determination in transitional weather conditions.
- 3.3 The Air Operator shall document the requirements of Subsection 3.1 and make a copy available to the Minister, upon reasonable notice by the Minister.
(effective 2020/12/09)
4. Accuracy of HOTDS Input Instruments and Holdover Time Determinations
- 4.1 The Air Operator shall verify that the manufacturer obtains test data and establish practices and procedures that demonstrate that the data inputs and holdover time determinations meet the accuracy requirements established for each element.
- 4.2 The Air Operator shall make the documentation required by Subsection 4.1 available to the Minister, upon reasonable notice by the Minister.
- 4.3 The Air Operator shall verify that the manufacturer has test data that demonstrates compliance of the data inputs and holdover time determinations with Subsection 4.1 in accordance with the following requirements:
- a) The test data shall be sufficiently complete to assure that the results are representative of the design and performance specifications of the system and include the following:
- i. For those instruments for which it is practical, the relationship between the value indicated by an instrument and the corresponding known value of a measure and;
- ii. The testing of instruments over a range that is representative of the expected environmental conditions (regardless of whether in a controlled environment or in the field); and
- iii. Testing of instruments in comparison with other instruments or human observations, in the outdoor operational environment, where practical.
- b) The test data shall consist of the following:
- i. Raw data collected during testing; and
- ii. The results of the reduction and analysis of the data.
- c) The Air Operator shall verify that the person verifying the test data in accordance with paragraph (d) confirms that the results of the reduction and analysis of the test data demonstrate that the data inputs and holdover time determinations meet the accuracy requirements set out in this Appendix under operational conditions encountered by the HOTDS;
- d) The Air Operator shall confirm that the manufacturer’s test data have been verified as meeting the accuracy requirements of this Appendix by a person who is:
- i. Independent from the manufacturer of the HOTDS and from the service provider and has a degree in the natural or applied sciences of mathematics from a recognized university and experience in: instrumental references, standards and traceability, methods of statistical analysis and an understanding of the operating principles and use of the instruments involved; or
- ii. A licensed professional engineer (P.Eng.) in Canada.
- e) The Air Operator shall verify that the manufacturer obtains a written confirmation of the verification of the test data from the person who verified the test data pursuant to paragraph (d) and shall, upon reasonable notice by the Minister, provide a copy to the Minister;
- f) The Air Operator shall ensure that the manufacturer demonstrates and confirms that the HOTDS has built-in fault detection checks that, in the event of system input/output failure (such as loss of an input instrument or corruption of data in a Holdover Time Determination Report (HOTDR) or other critical system hardware or software failure, prevent a misleading report from being issued. Demonstration shall be carried out on an end-to-end basis from input instruments in the field to delivery of HOTDR to the Air Operator.
- g) The Air Operator shall ensure that the manufacturer demonstrates initial and ensures ongoing quality assurance of the computational software, hardware and end to end data integrity as follows:
- i. The software must be designed, developed, produced and maintained in accordance with appropriate software assurance standards;
- ii. The hardware must be designed, developed, produced and maintained in accordance with appropriate hardware assurance standards; and
- iii. End-to-end data integrity shall include means of minimizing misleading data caused by all sources (ex: corrupted fluid coefficients, corrupted data transmissions) through the use of CRC checks or similar safeguards.
- h) The Air Operator shall ensure that the manufacturer confirms that the accuracy of the timing methods or device used to establish the time of the report is sufficient for the intended purpose; and
- i) The Air Operator shall ensure that the manufacturer documents the processes and procedures used to comply with the requirements of paragraphs (a) and (h) and shall make them available to the Minister, upon reasonable notice by the Minister.
- a) The test data shall be sufficiently complete to assure that the results are representative of the design and performance specifications of the system and include the following:
(effective 2020/12/09)
5. Technical Requirements for Data Inputs and Holdover Time Determinations
- 5.1 The Air Operator shall ensure that the manufacturer establishes and document practices and procedures for compliance with the provisions of Subsections 5.1.1 thru 5.1.23, which are applicable to the manufacturer’s HOTDS, and make a copy available to the Minister, upon reasonable notice by the Minister.
Wind
- 5.1.1 If required by the HOTDS, surface wind data inputs shall meet the following requirements:
- a) Wind instruments shall be ice resistant by design;
- b) The instruments shall be sited so as to provide representative input to any compensation factors that are generated to correct precipitation accumulation rates during high wind conditions; and
- c) The instruments shall function for winds up to 100 knots.
- 5.1.2 The accuracy of wind sensors and outputs shall be such that;
- a) The direction, if utilized, is correctly measured within ± 10 degrees; and
- b) The mean speed is correctly measured within ± 2 knots up to 20 knots and with 10% above 20 knots.
- 5.1.3 The accuracy of the wind instruments shall be established in accordance with Subsection 5.1.2, paragraphs (a) and (b), to at least a 95% confidence in wind tunnel testing.
Precipitation
- 5.1.4 Systems used for the determination of precipitation shall:
- a) Meet or exceed accuracy requirements as follows with reference to human observations:
- i. Correctly detect the presence of precipitation of a water equivalent rate of at least 2.0 g/dm2/h, other than drizzle, at least 90% of the time;
- ii. Correctly detect the presence of and distinguish between liquid or frozen precipitation, of a water equivalent rate of at least 2.0 g/dm2/h, at least 80% of the time; and
- iii. Correctly detect the presence of ice accretion or freezing precipitation, of at least 2.0 g/dm2/h, with at least a 90% probability.
- b) Differentiate between and, where applicable determine the intensity of: rain, freezing rain/freezing drizzle, and snow;
- c) Accurately detect the presence of fog, or freezing fog conditions;
- d) Indicate that type of precipitation is “unknown”, if the type cannot be determined; and
- e) In the event of unknown precipitation, the equipment shall report that a holdover time is unavailable.
- a) Meet or exceed accuracy requirements as follows with reference to human observations:
Temperature
- 5.1.5 Temperature measurements shall be accurate to within 1°C.
- 5.1.6 The accuracy requirements of Subsection 5.1.5 shall be demonstrated with at least a 95% confidence level during laboratory testing that is traceable to a reference standard.
Precipitation Rate
- 5.1.7 Precipitation rate measurements shall be analyzed in reference to simultaneously recorded glycol pan measurements for all precipitation types, excluding freezing fog.
- 5.1.8 The HOTDS precipitation rate measurements shall conform to the glycol pan measurements within the following tolerances:
a) From 0 to 10 g/dm2/h:
+/- 3.0 g/dm2/h
b) Above 10 g/dm2/h to 25 g/dm2/h:
+/- 6.0 g/dm2/h
c) Above 25 g/dm2/h:
+/- 14.0 g/dm2/h
- 5.1.9 The accuracy requirements of Subsection 5.1.8 shall be demonstrated with at least a 95% confidence level during comparative tests with the HOTDS and glycol pans.
- 5.1.10 The precipitation rate input for the purpose of computing fluid holdover time (Subsections 5.1.12 to 5.1.18) shall be:
- a) the precipitation rate determined by the HOTDS; plus
- b) the tolerance (within a 95% confidence level) that has been demonstrated for each precipitation type and range in 5.1.8, specific to that HOTDS.
- 5.1.11 Notwithstanding section 5.1.10, the precipitation rate input for the purpose of computing fluid holdover time (Subsections 5.1.12 to 5.1.18) shall not be less than 2.0 g/dm2/h.
Holdover Time Determinations
- 5.1.12 The HOTDS shall incorporate the most current regression curves and associated coefficients. These regression curves and associated coefficients are:
- 5.1.12.1 those obtained from or published by TC; or
- 5.1.12.2 those where traceability and validity has been demonstrated to be equivalent to those in 5.1.12.1.
- 5.1.13 Holdover time determinations from the system for all de/anti-icing fluids shall be computed using the regression curves and associated coefficients referenced in 5.1.12.
- 5.1.14 Holdover time determinations from the system, shall be verified, for each fluid, against known fluid dilution, precipitation type, rate and temperature inputs to ensure that regression curves and associated coefficients have been correctly implemented within the system.
As a minimum this verification will include:
- 5.1.14.1 normal range test cases; and
- 5.1.14.2 test cases outside the normal range to verify robustness.
- 5.1.15 Holdover time determinations for freezing drizzle or freezing rain conditions shall be based on computing the associated holdover time for each one of those precipitation conditions and using the resulting lowest value. The lowest precipitation rate input for this calculation will be 5 g/dm2/h unless a lower Lowest Use Precipitation Rate (LUPR) in freezing drizzle or freezing rain is published in the documents referenced in 5.1.12.
- 5.1.16 Holdover time determinations shall be inhibited in freezing precipitation (freezing fog, freezing drizzle or freezing rain) conditions exceeding 25 g/dm2/h.
- 5.1.17 Holdover time determinations shall be inhibited in snow conditions exceeding 50 g/dm2/h.
- 5.1.18 Holdover time determinations shall be inhibited in rain on cold soaked wing conditions exceeding 75 g/dm2/h.
- 5.1.19 In accordance with the currently accepted practice for HOT table development, holdover time determinations from the system for Type II, III and IV de/anti-icing fluids shall be capped as follows:
Freezing Fog
4 hrs;
Snow
2 hrs;
Freezing Drizzle
2 hrs;
Light Freezing Rain
2 hrs;
Rain on Cold Soaked Wing
2 hrs;
- 5.1.20 Where applicable, the notes, conditions, cautions incorporated into the annually published holdover time guidelines shall be respected in computation outputs by the HOTDS.
- 5.1.21 0°C must be input into the HOTDS regression calculation when measured temperature is above 0°C.
Holdover Time Determination Reports (HOTDR)
- 5.1.22 A HOTDR shall contain as a minimum de/anti icing holdover time(s) and fluid type. The report may contain additional items such as:
- a) Precipitation type;
- b) Precipitation intensity;
- c) Precipitation trend; and
- d) Fluid brand
These additional items shall be as agreed to with the service provider and/or the aircraft operator.
- 5.1.23 The air operator shall ensure that the service provider retains a copy of each HOTDR for at least 24 months.
- 5.1.24 The air operator provide a copy of a HOTDR as required by 5.1.22 to the Minister, upon reasonable notice by the Minister.
(effective 2020/12/09)