11/17/2011 AC 23.1309-1EAppendix 2APPENDIX 2. SAMPLE FUNCTIONALHAZARD ASSESSMENT (FHA) FORMAT*Note: This sample FHA is intended to be a guide for formatpurposes only to illustrate what items should be considered whenperforming an FHA. Since other pertinent information regardingthe type of airplane and its features is not provided, the technicalcontent may not be appropriate for other airplanes.A2-1Function Failure ConditionHazard DescriptionPhase Effect of Failure Condition onAircraft/CrewClassification Reference toSupportingMaterialVerificationDisplay ofattitudeinformationto control rolland pitchLoss of primary meansof attitude informationused for control in rolland pitch.Information fromstandby or other meansstill available.All Crew would not be able to useprimary means of attitudeinformation and would have toresort to standby or other means.As long as it is clear that theprimary means cannot be reliedupon, then using the standby orother means would create anincrease in crew workload, butdoubtful anything more severe.Hypothetical cases where it is notclear as to the integrity of theinformation may come under the“Misleading attitude information”case below.Major AC 23.1311-1CQualitativeanalysis.May requireFTAMay use PSSAor SSADisplay ofattitudeinformationto control rolland pitchLoss of all means ofattitude information.All If certified for IFR operation, thecrew would not have sufficientinformation to maintain a properattitude and would likelyinadvertently exceed attitudelimits, which could result in theloss of control of the aircraft.Catastrophic AC 23.1311-1CQuantitativeFTA andQualitativeanalysis.May use PSSAor SSA11/17/2011 AC 23.1309-1EAppendix 2APPENDIX 2. SAMPLE FUNCTIONALHAZARD ASSESSMENT (FHA) FORMAT*Note: This sample FHA is intended to be a guide for formatpurposes only to illustrate what items should be considered whenperforming an FHA. Since other pertinent information regardingthe type of airplane and its features is not provided, the technicalcontent may not be appropriate for other airplanes.A2-2Function Failure ConditionHazard DescriptionPhase Effect of Failure Condition onAircraft/CrewClassification Reference toSupportingMaterialVerificationDisplay ofattitudeinformationto controlroll andpitchIncorrect attitudeinformation on onedisplay, but not on alldisplays (not misleadingin nature).AllGenerally, this condition would bethe incorrect attitude with warningon one means of attitudeinformation. For this condition,the crew would realize that thisinformation was incorrect. If thereis any chance this would not beclear, the scenario would have tobe considered “Misleading attitudeinformation” as described below.MajorAC 23.1311-1CQualitativeanalysis.May requireFTAMay use PSSAor SSADisplay ofattitudeinformationto controlroll andpitchMisleading attitudeinformation.Note: Failure conditionwith misleading dataprovided to the autopilotthat is handled with theautopilot failureconditions.AllIf certified for IFR operation, thecrew would unknowingly followincorrect attitude information, andinadvertently exceed attitude limitswhich could result in the loss ofcontrol of the aircraft.CatastrophicAC 23.1311-1CQuantitativeFTA andQualitativeanalysis.May use PSSAor SSADisplay ofpowerplantindicationoil pressureTotal Loss of oil pressuredisplayAll Assumes oil temperature is used asa backupMinor AC 23.1311-1CDesign andInstallationAppraisal(Nextfunction)(Next failure condition,and so on)