OSO 20 – Human Factors evaluation
AMC1 Article 11 Annex E. Operational Safety Objective 20
CAA ORS9 Decision No. 46
OSO 20 – A Human Factors evaluation has been performed and the HMI found appropriate for the mission
Level of integrity
| Criterion | Low (SAIL 2, 3) | Medium (SAIL 4, 5) | High (SAIL 6) |
|---|---|---|---|
| Criterion | OSO20.L.I |
OSO20.L.I |
OSO20.L.I OSO20.H.I |
Level of assurance
| Criterion | Low (SAIL 2, 3) | Medium (SAIL 4, 5) | High (SAIL 6) |
|---|---|---|---|
| Criterion | OSO20.L.A |
OSO20.L.A OSO20.M.A |
OSO20.M.A OSO20.H.A |
| Alternative FTB method | OSO20.FT.L.A | OSO20.FT.L.A (SAIL 4 only) | Not applicable |
Low level of robustness (SAIL 2 and 3)
OSO20.L.I
(a) The UAS information and control interfaces must be clearly and succinctly presented and must not confuse, cause unreasonable fatigue, or contribute to remote crew error that could adversely affect the safety of the operation.
(b) If an electronic means is used to support the remote crew members in their role to maintain awareness of the position of the unmanned aircraft, its HMI:
(1) Must be sufficient to allow the remote crew members to determine the position of the UA during operation.
(2) Must not degrade the remote crew members’ ability to scan the airspace visually where the UA is operating for any potential collision hazard.
(3) Must not degrade the remote crew members’ ability to maintain effective communication with the remote pilot at all times.
OSO20.L.A
(a) The Applicant must conduct a human factors evaluation of the UAS to demonstrate that the HMI is appropriate for the mission.
(b) The HMI evaluation must be based on inspection or analysis.
(c) If (a), (b) and Integrity requirements are complied with through a SAIL mark certificate, the Applicant must demonstrate that the HMI is appropriate for the intended operation.
(d) The Applicant must declare and provide evidence of compliance with the Integrity requirements. The detailed evidence of compliance may be assessed by the CAA.
OSO20.FT.L.A
The applicant must provide evidence of FTB flight hours proportionate to the risk/SAIL of the operation meeting one of the set of conditions described in the FTB policy.
(a) Within the full operational scope/envelope of the intended operation, and
(b) Following the operational procedures and the remote crew training referred to in the OA application.
AMC.OSO20.L.A
Annex E – AMC 1 Integrity and assurance levels for the Operational Safety Objectives (OSO) paragraph 1.5 provides further information about proposing a standard as an AMC.
Medium level of robustness (SAIL 4 and 5)
Lower robustness level requirements to be complied with:
• OSO20.L.I
Additional requirements to be compiled with:
OSO20.M.I
No additional requirements.
OSO20.M.A
(a) The Applicant must conduct a human factors evaluation of the UAS to demonstrate that the HMI is appropriate for the mission.
(b) The HMI evaluation must be based on demonstrations or simulations.
(c) If compliance evidence is provided through simulation, the validity of the target environment used in the simulation must be justified.
(d) If (a), (b), (c) and Integrity requirements are complied with through a SAIL mark certificate, the Applicant must demonstrate that the HMI is appropriate for the intended operation.
(e) The Applicant must provide evidence of compliance with Integrity requirements, which will be assessed by the CAA.
OSO20.FT.M.A
The Applicant must comply with the requirements of OSO20FT.L.A (SAIL IV only).
AMC.OSO20.M.A
Annex E – AMC 1 Integrity and assurance levels for the Operational Safety Objectives (OSO) paragraph 1.5 provides further information about proposing a standard as an AMC.
High level of robustness (SAIL 6)
Lower robustness level requirements to be complied with:
• OSO20.L.I
• OSO20.M.A
Additional requirements to be compiled with:
OSO20.H.I
The Human factors evaluation must include:
(a) An appraisal to verify that the remote crew workload remains acceptable in both normal and emergency situations.
(b) An appraisal of the efficiency of the emergency procedures in terms of efficacy of the actions and the expected potential latencies.
(c) An analysis to verify the correct prioritisation of alarms in an emergency situation.
OSO20.H.A
(a) The Applicant must provide evidence of compliance with the Integrity requirements, which will be assessed by the CAA. The CAA will validate continuing compliance through oversight.
(b) The CAA may request to witness the HMI evaluation.
GM1 Article 11 Annex E Operational Safety Objective 20
CAA ORS9 Decision No. 46
GM.OSO20.L.A (c)
This may take the form of a report explaining the rationale behind the choice of UAS and aspects of the HMI that make it suitable for the intended operation.
GM.OSO20.FT.L.A
The FTB method is an alternative means of compliance with OSO 20 assurance requirements.
Compliance with the requirement provides assurance that the operational procedures are adequate at the level corresponding to the SAIL being demonstrated by the FTB approach.
As an example, if the number of test cycles supporting the FTB flying hours is proportionate to the risk of a SAIL III operation (i.e. 3,000 FH), the assurance level for OSO 20 is satisfied at a low level of robustness.
GM.OSO20.M.A (d)
This may take the form of a report explaining the rationale behind the choice of UAS and aspects of the HMI that make it suitable for the intended operation.
GM.OSO20.H.I (c)
In an emergency situation, multiple failures may lead to multiple alarms that distract and prevent the remote pilot from determining the appropriate response. If this is the case, alarms of lesser importance might be minimised or ignored by design or procedure.