AC 27-1B, Chg 7 2/4/2016 Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 34-00-00 - NAVIGATION ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supportin g Material Verification Method Misleading indication and/or malfunction of attitude in IFR.
ALL The reduction in safety margins and functional capability in the system may prohibit continued safe flight and landing.
Analysis Misleading indication and/or malfunction of attitude in VFR – night.
ALL Aircrew workload may increase to a level such that they could not be relied upon to perform tasks accurately or completely.
Analysis and Test 3420 Heading Total loss of ALL heading indication in IFR.
ALL Aircrew workload significantly increases due to utilizing alternate methods to determine heading (NAV radios, ATC assistance, etc.).
Analysis and Test Total loss of ALL heading indication in VFR – night.
ALL Aircrew workload significantly increases due to utilizing alternate methods to determine heading (NAV radios, ATC assistance, etc.).
Analysis and Test Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 30
Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 34-00-00 - NAVIGATION ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supportin g Material Verification Method Misleading ALL Aircrew workload Analysis and indication substantially increases to Test and/or a level at which the crew malfunction cannot accurately of the complete tasks due to heading in utilizing alternate IFR. methods to determine heading (NAV radios, ATC assistance, etc.).
Misleading ALL Aircrew workload Analysis and indication substantially increases to Test and/or a level at which the crew malfunction cannot accurately of the complete tasks due to heading in utilizing alternate VFR – night. methods to determine heading (NAV radios, ATC assistance, etc.).
3400 Navigation System Total loss of all navigation information in IFR.
ALL Aircrew workload significantly increases to a level at which the crew cannot accurately complete tasks.
Analysis Total loss of ALL Aircrew workload all navigation significantly increases to information a level at which the crew in VFR – cannot accurately night. complete tasks.
Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 31
AC 27-1B, Chg 7 2/4/2016 Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 34-00-00 - NAVIGATION ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supportin g Material Verification Method Misleading indication and/or malfunction of the navigation in IFR.
ALL Continued safe flight is not guaranteed due to misleading navigation information resulting in terrain or obstacle impact.
Analysis and Test Misleading indication and/or malfunction of the navigation in VFR – night.
ALL Continued safe flight is not guaranteed due to misleading navigation information resulting in terrain or obstacle impact.
Analysis and Test Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 32
Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 63-00-00 – MAIN ROTOR DRIVE ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method 6310 Engine/ Transmission Coupling Provide torque Loss of TO Aircrew workload Analysis and and rotational engine to increases substantially Test speed to the transmission such that tasks cannot be rotor shaft (coupling) drive (single engine).
completed accurately.
Aircrew must conduct an autorotation.
Loss of TO Aircrew workload Analysis and engine to substantially increases to Test transmission handle an OEI (coupling) condition.
drive (dual engine).
Loss of TO Continued safe flight is Analysis and engine not guaranteed due to Test coupling seizure of free wheeling and loss of clutch results in loss of input MR rpm. Leads to module free- uncontrolled flight (no wheeling auto-rotation clutch capability.).
(single & dual engine).
6320 Main Rotor Gearbox Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 33
AC 27-1B, Chg 7 2/4/2016 Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 63-00-00 – MAIN ROTOR DRIVE ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method Provide torque and rotational speed to the rotor shaft.
Loss of lubrication to main transmission .
Cruise Aircrew workload increases substantially due to the need to conduct a landing as soon as possible.
Analysis and Test 6321 Main Rotor Brake Provide braking to the rotor Inadvertent activation of rotor braking system during flight.
ALL Continued safe flight is not guaranteed. For instance, engagement of the braking pad during high power to the main rotor could create a fire.
Analysis and Test 6340 Rotor Drive Indicating System Provide MGB chip detection Failure of chip detector system to detect and annunciate the existence of chips.
ALL Continued safe flight and landing is not guaranteed due to the degradation of gears below the required load capability.
Analysis and Test Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 34
Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 63-00-00 – MAIN ROTOR DRIVE ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method Provide MGB Loss of oil ALL A significant reduction Analysis and oil pressure pressure in safety margins would Test indication indication. exist due to the possible delay in crew action to an actual loss of oil.
Aircrew workload increases slightly due to changing the planned flight and the monitoring of secondary indications.
Erroneous ALL A substantial reduction Analysis and annuncia in safety margins would Test tion of low exist due to the delayed oil pressure reaction of the crew to warning. an actual loss of oil.
Slight increase in aircrew workload due to conflicting low oil pressure warning and oil pressure indicator.
Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 35
AC 27-1B, Chg 7 2/4/2016 Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 63-00-00 – MAIN ROTOR DRIVE ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method Loss of oil ALL Large reduction in the Analysis and pressure aircraft safety margin; Test indication cannot determine if and low oil adequate oil pressure is pressure present. Secondary cues warning. may be present to pilot (Increase oil temperature, vibration and noise levels, in case of actual loss of MGB oil).
Substantial increase in aircrew workload.
Misleading ALL Significant reduction in Analysis and oil pressure the aircraft safety Test indication. margin due to erroneous oil pressure indication (reads normal but actual oil pressure is low).
Substantial increase in aircrew workload.
Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 36
Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 63-00-00 – MAIN ROTOR DRIVE ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method Misleading oil pressure indication and loss of low oil pressure warning.
ALL Continued safe flight is not guaranteed due to loss of all indications of MGB oil pressure loss and ensuing gearbox seizure.
Analysis Provide Nr indication Loss of rotor RPM (Nr) indication.
ALL Slight increase in aircrew workload due to the need to monitor secondary engine instruments.
Analysis and/or Test Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 37
AC 27-1B, Chg 7 2/4/2016 Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 73-00-00 - ENGINE FUEL AND CONTROL ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method 7331 Fuel Flow Indicating Loss of fuel flow.
ALL The reduction in safety margins and functional capability in the system may prohibit continued safe flight and landing.
Analysis Malfunction and loss of fuel flow indication.
ALL The failure can delay crew action long enough to prevent continued safe flight and landing.
Analysis Misleading fuel flow alert failed.
ALL A large reduction in safety margins or functional capabilities.
Analysis 7332 Fuel Pressure Indicating Loss of fuel pressure.
ALL The reduction in safety margins and functional capability in the system may prohibit continued safe flight and landing.
Analysis Malfunction and loss of fuel pressure indication.
ALL A combination of a malfunction with a loss of indication in the system can delay crew action long enough causing a large reduction in safety margins or functional capabilities.
Analysis and Test Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 38
Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 73-00-00 - ENGINE FUEL AND CONTROL ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method Misleading fuel pressure indication.
ALL If the indication to the pilot is a warning, the likely requirement is to land immediately.
Worst case is ditching in poor conditions causing a large reduction in safety margins or functional capabilities.
Analysis Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 39
AC 27-1B, Chg 7 2/4/2016 Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 75-00-00 - AIR ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method 7510 Engine Anti- Icing (A/I) System Loss of a single engine A/I system on a multi-engine aircraft.
Cruise A significant loss of safety margin due to loss of a critical redundant system.
Significant increase in pilot workload.
Analysis and Test Loss of Cruise Results in a large Analysis and engine A/I reduction in aircraft Test system on a safety margin and a single large increase in pilot engine workload.
aircraft.
7532 Compressor Bleed Valve Malfunction
- valve is failed OPEN on one engine of a multi-engine aircraft.
Cruise May cause an engine stall or surge that leads loss of one engine.
Significant increase in pilot workload.
Analysis and Test Malfunction Cruise May cause an engine Analysis and
- valve is stall or surge that leads Test failed OPEN loss of the engine.
on one More than a significant engine on a increase in pilot single workload as the crew engine will likely have to land aircraft. as soon as possible.
Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 40
Note: Not all ATA chapters or subchapters have been included. Also, the italicized entries are not usually included in the failure condition description but in the systems description or assumptions section.
ATA 75-00-00 - AIR ATA Function Description Failure Condition (FC) Phase of Operation Effect of the Failure on the Aircraft, Crew and Occupants Classification of the FC Notes (assumptions) Supporting Material Verification Method 7540 Bleed Air Indicating System Loss of bleed air indication.
ALL A slight reduction in safety margins.
A slight increase in pilot workload.
Analysis and Test Misleading bleed air indication.
ALL Misleading indication may cause an inappropriate engine setting resulting in a significant reduction in system safety margins.
Analysis and Test Figure AC 27 MG 21-1. Generic Examples by ATA.
Page MG 21 - 41