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GM2 ORO.AOC.130 Flight data monitoring — aeroplanes
ED Decision 2025/020/R
EXAMPLES OF FDM EVENTS
The following table provides examples of FDM events that may be further developed using operator and aeroplane specific limits. The table is considered illustrative and not exhaustive. Other examples may be found in the documents published by the European Operators Flight Data Monitoring (EOFDM) forum.
Event Group | Description |
Rejected take-off | High speed rejected take-off |
Take-off pitch | Pitch rate low or high on take-off |
Pitch attitude high during take-off | |
Unstick speeds | Unstick speed high |
Unstick speed low | |
Height loss in climb-out | Initial climb height loss 20 ft above ground level (AGL) to 400 ft above aerodrome level (AAL) |
Initial climb height loss 400 ft to 1 500 ft AAL | |
Slow climb-out | Excessive time to 1 000 ft AAL after take-off |
Climb-out speeds | Climb-out speed high below 400 ft AAL |
Climb-out speed high 400 ft AAL to 1 000 ft AAL | |
Climb-out speed low 35 ft AGL to 400 ft AAL | |
Climb-out speed low 400 ft AAL to 1 500 ft AAL | |
High rate of descent | High rate of descent below 2 000 ft AGL |
Missed approach | Missed approach below 1 000 ft AAL |
Missed approach above 1 000 ft AAL | |
Low approach | Low on approach |
Glideslope | Deviation under glideslope |
Deviation above glideslope (below 600 ft AGL) | |
Approach power | Low power on approach |
Approach speeds | Approach speed high within 90 seconds of touchdown |
Approach speed high below 500 ft AAL | |
Approach speed high below 50 ft AGL | |
Approach speed low within 2 minutes of touchdown | |
Landing flap | Late land flap (not in position below 500 ft AAL) |
Reduced flap landing | |
Flap load relief system operation | |
Landing pitch | Pitch attitude high on landing |
Pitch attitude low on landing | |
Bank angles | Excessive bank below 100 ft AGL |
Excessive bank 100 ft AGL to 500 ft AAL | |
Excessive bank above 500 ft AGL | |
Excessive bank near ground (below 20 ft AGL) | |
Normal acceleration | High normal acceleration on ground |
High normal acceleration in flight flaps up (+/- increment) | |
High normal acceleration in flight flaps down(+/- increment) | |
High normal acceleration at landing | |
Abnormal configuration | Take-off configuration warning |
Early configuration change after take-off (flap) | |
Speed brake with flap | |
Speed brake on approach below 800 ft AAL | |
Speed brake not armed below 800 ft AAL | |
Ground proximity warning | Ground proximity warning system (GPWS) operation - hard warning |
GPWS operation — soft warning | |
GPWS operation — windshear warning | |
GPWS operation — false warning | |
Airborne collision avoidance system (ACAS II) warning | ACAS operation — Resolution Advisory |
Margin to stall/buffet | Stick shake |
False stick shake | |
Reduced lift margin except near ground | |
Reduced lift margin at take-off | |
Low buffet margin (above 20 000 ft) | |
Aircraft flight manual limitations | Maximum operating speed limit (VMO) exceedance |
Maximum operating speed limit (MMO) exceedance | |
Flap placard speed exceedance | |
Gear down speed exceedance | |
Gear selection up/down speed exceedance | |
Flap/slat altitude exceedance | |
Maximum operating altitude exceedance |
[applicable until 31 December 2027 — ED Decision 2021/005/R]
EXAMPLES OF FDM METHODS
Table 1 of this GM provides examples of precursors of incidents that could be monitored through an FDM programme, by means of FDM events or FDM measurements. It is acknowledged that monitoring some of these example precursors may be very complex or the necessary flight parameters may not always be recorded. Methods to monitor these example precursors may be further developed using operator- and aeroplane-specific limits. Therefore, Table 1 is considered illustrative and not exhaustive.
Note 1: Key risk areas, as described in the Annex to Commission Delegated Regulation (EU) 2020/2034, correspond to the aviation occurrence categories defined by the Commercial Aviation Safety Team / International Civil Aviation Organization Common Taxonomy Team, as follows:
—‘excursion’ corresponds to ‘runway excursion’ (RE);
—‘aircraft upset’ corresponds to ‘loss of control in flight’ (LOC-I);
—‘terrain collision’ corresponds to ‘controlled flight into or toward terrain’ (CFIT);
—‘airborne collision’ corresponds to ‘aircraft proximity / TCAS alert / loss of separation / near midair collision / midair collision’ (MAC).
Note 2: Please refer to the European Operators Flight Data Monitoring forum (EOFDM) document Guidance for the implementation of flight data monitoring precursors for further details on methods to monitor the example precursors of incidents provided in Table 1.
Note 3 The far-right column of Table 1 only indicates the occurrence types directly related to the precursors of incidents among those listed in Annex I ‘Occurrences related to the operation of the aircraft’ to Commission Implementing Regulation (EU) 2015/1018. The precursors listed in Table 1 may also be used to detect occurrence types other than those indicated in the far-right column.
Note 4: In addition to the precursors of incidents in Table 1, operators may need to monitor caution and warning alerts displayed to the flight crew and other indications that the airworthiness of the aircraft may be affected. FDM events or measurements that monitor significant deviations from the standard operating procedures (SOPs) in all phases of flight, including when the aircraft is on the ground, are also advisable. For brevity, Table 1 does not include such events.
Table 1 — Examples of potential precursors of incidents that could be monitored through an FDM programme
No | Number and title of the precursor as per EOFDM documentation | Description of the precursor as per EOFDM documentation | Relevant key risk area as described in the Annex to Commission Delegated Regulation (EU) 2020/2034 | Occurrence types as defined in Annex I to Commission Implementing Regulation (EU) 2015/1018 that are directly related to the precursor |
1 | RE01 — Engine power changes during take-off | Develop means to detect engine power changes during take-off that may lead to a runway excursion | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
2 | RE02 — Inappropriate aircraft configuration | Develop means to detect inappropriate aircraft configuration (lifting devices, pitch trim) that could cause take-off and landing performance problems; not all aircraft are equipped with take-off configuration warning systems and some of these systems cannot detect all types of configuration errors | Excursion (at take-off and landing) | 1.3(6) Actual or attempted take-off, approach or landing with incorrect configuration setting |
3 | RE03 — Monitoring the centre-of-gravity (CG) position | Develop means to detect CG out of limits on take-off or not consistent with the pitch trim settings | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
4 | RE04 — Reduced elevator authority | Develop means to detect abnormal rotation in response to elevator inputs, reduced elevator movement or excessive force required to move the elevator surfaces | Excursion (at take-off and landing) | 2.1(7) Abnormal functioning of flight controls, such as asymmetric or stuck/jammed flight controls (e.g. lift (flaps/slats), drag (spoilers), attitude control (ailerons, elevators, rudder) devices) |
5 | RE05 — Slow acceleration | Develop means to measure the acceleration during the take-off roll and to detect abnormal values, taking into account the various factors that affect the take-off performance | Excursion (at take-off and landing) | 1.3(5) Inability to achieve required or expected performance during take-off, go-around or landing |
6 | RE06 — Aircraft malfunction | Develop means to detect aircraft malfunctions that are likely to cause rejected take-offs (e.g. ‘master warning’ and ‘master caution’ alerts and airspeed indication disagreements) | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
7 | RE07 — Late rotation | Develop means to detect rotations conducted after the rotation speed or beyond the expected distance (or time) after the start of the take-off roll | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
8 | RE08 — Slow rotation | Develop means to detect slow rotation | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
9 | RE09 — No lift-off | Develop means to detect late lift-off (in time and/or distance) after rotation or start of the take-off roll | Excursion (at take-off and landing) | 1.3(5) Inability to achieve required or expected performance during take-off, go-around or landing |
10 | RE10 — Rejected take-off | Develop means to identify rejected take-off | Excursion (at take-off and landing) | 1.3(4) Any rejected take-off |
11 | RE11 — Runway remaining after rejected take-off | Develop means to estimate the runway remaining ahead of the aircraft after the start of the rejected take-off and to estimate the ground distance spent during the rejected take-off | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
12 | RE12 — Inadequate use of stopping devices | Develop means to identify late or inadequate activation of thrust reverser, brakes, airbrakes or other stopping devices during rejected take-offs and landings | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
13 | RE13 — Insufficient deceleration | Develop means to detect slow deceleration after landing or rejected take-off, taking into consideration the various factors that affect the landing and the rejected take-off performance | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
14 | RE14 — Incorrect input performance data | Develop means to detect erroneous data entry or calculation errors that could lead to incorrect thrust settings, incorrect V speeds or incorrect target approach speeds | Excursion (at take-off and landing) | 1.1(1) Use of incorrect data or erroneous entries into equipment used for navigation or performance calculations that has or could have endangered the aircraft, its occupants or any other person |
15 | RE15 — Runway remaining at lift-off | Develop means to estimate the runway remaining ahead of the aircraft at the moment of lift-off and to detect abnormal values | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
16 | RE16 — Aircraft handling | Develop means to monitor the use of aircraft controls (rudder and nose-wheel steering) and brakes during take-off, rejected take-off and landing, and to detect non-standard cases. In addition, monitor simultaneous control inputs of both flight crew and analyse their potential negative influence on safety | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
17 | RE17 — Crosswind | Develop means to estimate the crosswind during take-off, approach and landing and to detect abnormal values | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
18 | RE18 — Forward thrust asymmetry | Develop means to identify forward thrust asymmetry during the take-off roll | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
19 | RE19 — Steering system malfunction | Develop means to identify problems with the steering system, which could affect lateral controllability | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
20 | RE20 — Lateral deviation | Develop means to identify excessive lateral deviations or oscillations during take-off, rejected take-off and landing, taking into consideration the runway width | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
21 | RE21 — Reverse thrust asymmetry | Develop means to identify reverse thrust asymmetry during a rejected take-off or landing | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
22 | RE22 — Braking asymmetry | Develop means to identify braking asymmetry during a rejected take-off or landing (possibly in combination with RE12 ‘Inadequate use of stopping devices’) | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
23 | (Reserved) | |||
24 | RE24 — Tailwind | Develop means to estimate the tailwind during take-off, approach and landing | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
25 | RE25 — Excessive engine power | Develop means to monitor the engine power reduction before touchdown and to identify abnormal engine utilisation in this phase of the flight | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
26 | RE26 — Unstable approach | Develop means to identify and quantify unstable approaches, regardless of whether they result in go-around manoeuvres | Excursion (at take-off and landing) | 1.3(8) Approach continued against air operator stabilised approach criteria |
27 | RE27 — High energy over the threshold | Develop means to estimate the height, airspeed and ground speed while crossing the runway threshold | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
28 | RE28 — Long flare | Develop means to detect the start of the flare and to estimate the ground distance the aircraft has covered from the start of the flare until touchdown | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
29 | RE29 — Deep landing | Develop means to estimate the distance from the runway threshold until the touchdown point and also the runway length available after touchdown | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
30 | RE30 — Abnormal runway contact | Develop means to identify and quantify bounced (main or nose wheels), off-centre, nose-first or asymmetrical landings as well as tail and wingtip strikes | Excursion (at take-off and landing) | 1.3(7) Tail, blade/wingtip or nacelle strike during take-off or landing 1.3(12) Hard landing |
31 | RE31 — Go-around | Develop means to identify go-arounds and balked landings | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
32 | RE32 — Excessive energy at touchdown | Develop means to correctly identify the touchdown instant, to measure airspeed and ground speed and to identify cases of excessive energy | Excursion (at take-off and landing) | No direct link to a specific type of occurrence) |
33 | RE33 — Wrong runway or wrong runway entry point used | The difference between actual and planned runway or runway entry point used should be monitored | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
34 | RE34 — Erroneous guidance | Develop means to detect cases of erroneous guidance during approach and landing | Excursion (at take-off and landing) | No direct link to a specific type of occurrence |
35 | LOC01 — Fire, smoke and fumes | Develop means to detect the presence of fire, smoke or fumes in the cabin, cargo compartment, engines and landing gear bay | Aircraft upset | 4(2) Any burning, melting, smoke, fumes, arcing, overheating, fire or explosion |
36 | LOC02 — Pressurisation system malfunction | Develop means to identify malfunctions of the pressurisation system that could cause crew incapacitation or discomfort. System malfunctions could cause abnormal or unexpected rates of cabin pressure, inability to cope with transients in engine regime, abnormal cabin altitude (not necessarily high enough to trigger alerts for the crew) or reversion from automatic control to manual. There might be scope for integration with the aircraft health monitoring systems and support for continued airworthiness | Aircraft upset | 4(7) Uncontrollable cabin pressure |
37 | LOC03 — Pressurisation system misuse | Develop means to identify the situations where the pressurisation system is not used correctly, for example failure to turn on the bleed pressure after take-off, failure to set the landing pressure altitude or inadequate use of the manual control mode | Aircraft upset | No direct link to a specific type of occurrence |
38 | (Reserved) | |||
39 | LOC05 — High cabin altitude | Develop means to identify situations of abnormal cabin altitude, including but not limited to values that would trigger cabin altitude alerts (possibly in combination with LOC02 ‘Pressurisation system malfunction’) | Aircraft upset | No direct link to a specific type of occurrence |
40 | LOC06 — Oxygen (O2) masks not deployed and not used by the crew | Develop means to identify situations where the crew failed to deploy and use the O2 masks in response to real or nuisance situations | Aircraft upset | 4(9) Any use of crew O2 system by the crew |
41 | LOC07 — Supplementary O2 system failure | Develop means to identify the failure of or leaks in the flight crew supplementary O2 system | Aircraft upset | 4(9) Any use of crew O2 system by the crew |
42 | LOC08 — Centre of gravity (CG) out of limits | Develop means to estimate the CG position and to detect situations where it is beyond the limits or not consistent with the pitch trim settings as a result of load shifts, incorrect loadings or fuel imbalance | Aircraft upset | No direct link to a specific type of occurrence |
43 | LOC09 — Abnormal operations | Develop means to identify operations at or beyond the edges of the operating envelope or not in compliance with SOPs. This should cover all airframe and engine limitations (as specified in the aircraft flight manual, including but not limited to indicated airspeed/Mach versus altitude, vertical speed, G limits, flap speed limits, speed brake limits, tyre speed limits, landing gear limits, temperature limits, manoeuvrability speeds, engine parameters, tailwind, crosswind, excessive rudder inputs) | Aircraft upset | 1.4(6) Exceedance of aircraft flight manual limitation 2.2(4) Engine operating limitation exceedance, including overspeed or inability to control the speed of any high-speed rotating component (e.g. auxiliary power unit, air starter, air cycle machine, air turbine motor, propeller or rotor) |
44 | LOC10 — Incorrect performance calculation | Develop means to detect erroneous data entry or calculation errors that could lead to incorrect thrust settings, incorrect V speeds or incorrect target approach speeds (to be reconciled with recommendation RE01 for runway excursions) | Aircraft upset | 1.1(1) Use of incorrect data or erroneous entries into equipment used for navigation or performance calculations that has or could have endangered the aircraft, its occupants or any other person |
45 | LOC11 — Overweight take-off | Develop means to identify overweight take-off situations that could have an adverse effect on the climb performance and obstacle clearance for performance-limited departures (possibly in combination with LOC10 ‘Incorrect performance calculation’) | Aircraft upset | No direct link to a specific type of occurrence |
46 | LOC12 — Envelope protection systems | Develop means to detect in-flight activation of the envelope protection systems of the aircraft | Aircraft upset | 1.4(4) Activation of any flight envelope protection, including stall warning, stick shaker, stick pusher and automatic protections |
47 | LOC13 — Inadequate aircraft energy | Develop means to identify situations of inadequate aircraft energy (speed and/or altitude and/or thrust) for each phase of the flight | Aircraft upset | No direct link to a specific type of occurrence |
48 | LOC14 — Inadequate aircraft attitude | Develop means to identify cases of excessive angles of pitch and roll. The identification should take into consideration the range of values acceptable for each phase of flight | Aircraft upset | No direct link to a specific type of occurrence |
49 | LOC15 — Loss of lift | Develop means to identify situations of actual loss of lift and cases of operation close to the edges of the lift envelope | Aircraft upset | 1.4(4) Activation of any flight envelope protection, including stall warning, stick shaker, stick pusher and automatic protections |
50 | (Reserved) | |||
51 | LOC17 — Electromagnetic interference | Develop means to identify cues that could suggest situations of electromagnetic interference (possibly in combination with LOC24 ‘Instrument malfunction’) | Aircraft upset | No direct link to a specific type of occurrence |
52 | LOC18 — Adverse weather | Develop means to identify the presence of adverse weather in the vicinity of the aircraft | Aircraft upset | 5(9) A lightning strike which resulted in damage to the aircraft or loss or malfunction of any aircraft system 5(10) A hail encounter which resulted in damage to the aircraft or loss or malfunction of any aircraft system 5(11) Severe turbulence encounter or any encounter resulting in injury to occupants or deemed to require a ‘turbulence check’ of the aircraft 5(12) A significant wind shear or thunderstorm encounter which has or could have endangered the aircraft, its occupants or any other person 5(13) Icing encounter resulting in handling difficulties, damage to the aircraft or loss or malfunction of any aircraft system |
53 | LOC19 — Wind shear | Develop means to identify situations of wind shear (reactive and predictive) | Aircraft upset | 5(12) A significant wind shear or thunderstorm encounter that has or could have endangered the aircraft, its occupants or any other person |
54 | LOC20 — Severe turbulence | Develop means to identify situations of severe turbulence caused by different sources (clear-air turbulence, wake vortex, mountain waves, etc.) | Aircraft upset | 5(7) Wake-turbulence encounters 5(11) Severe turbulence encounter or any encounter resulting in injury to occupants or deemed to require a ‘turbulence check’ of the aircraft |
55 | LOC21 — Icing conditions | Develop means to identify situations of extremely cold conditions or icing of the engines, nacelles, propellers, wings and airframe. Operation in cold or icing conditions is frequent for most aircraft operations; therefore, they should not be considered abnormal. The objective is to develop a set of measurements to enable a better understanding of such environmental conditions in order to assess the response of the aircraft ice detection systems and to support recommendation LOC22 ‘De-icing system failure’ | Aircraft upset | 5(13) Icing encounter resulting in handling difficulties, damage to the aircraft or loss or malfunction of any aircraft system |
56 | LOC22 — De-icing system failure | Develop means to identify failure, ineffectiveness or incorrect utilisation (e.g. late activation) of de-icing and anti-icing systems | Aircraft upset | No direct link to a specific type of occurrence |
57 | LOC23 — Engine failure | Develop means to identify situations of latent or active engine failure, including foreign object damage and hardware degradation and failure. There might be scope for integration with engine health monitoring and continued airworthiness | Aircraft upset | 2.2(5) Failure or malfunction of any part of an engine, power plant, APU or transmission resulting in any one or more of the following: (a) thrust-reversing system failing to operate as commanded; (b) inability to control power, thrust or rpm (revolutions per minute); (c) non-containment of components/debris |
58 | LOC24 — Instrument malfunction | Develop means to identify situations of instrument malfunction (possibly in combination with LOC17 ‘Electromagnetic interference’) | Aircraft upset | 2.1(6) Malfunction or defect of any indication system when this results in misleading indications to the crew |
59 | (Reserved) | |||
60 | LOC26 — Loss of thrust | Develop means to identify situations of unintended loss of thrust, or reduced engine performance, taking into consideration (but not only) the range of values acceptable for each phase of flight and fuel flow | Aircraft upset | 2.2(1) Failure or significant malfunction of any part or controlling of a propeller, rotor or power plant 2.2(3) Flameout, in-flight shutdown of any engine or auxiliary power unit when required (e.g. extended range twin engine aircraft operations, minimum equipment list) |
61 | LOC27 — Hardware failure | Develop means to identify cues that could suggest the existence of latent failures in safety-critical components (including but not limited to landing gears, doors, brakes, wheels and hydraulic systems). There might be scope for integration with the aircraft health monitoring systems and continued airworthiness | Aircraft upset | No direct link to a specific type of occurrence |
62 | LOC28 — Flight control failure | Develop means to identify cues that could suggest failure or ineffectiveness of the flight controls | Aircraft upset | 2.1(7) Abnormal functioning of flight controls such as asymmetric or stuck/jammed flight controls (e.g. lift (flaps/slats), drag (spoilers), attitude control (ailerons, elevators, rudder) devices) |
63 | LOC29 — Mismanagement of automation | Develop means to identify situations of inadequate or unexpected use of automation or unexpected disconnection of automation | Aircraft upset | 1.4(9) Misinterpretation of automation mode or of any flight deck information provided to the flight crew that has or could have endangered the aircraft, its occupants or any other person |
64 | LOC30 — Abnormal flight control inputs | Develop means to identify situations of abnormal inputs into thrust controls, control surfaces and lifting devices, taking into consideration the range of values acceptable for each phase of flight | Aircraft upset | No direct link to a specific type of occurrence |
65 | LOC31 — Fuel exhaustion | Develop means to identify situations of low fuel quantity — by comparison with the planned fuel quantity — as the flight proceeds to its destination | Aircraft upset | 4(8) Critically low fuel quantity or fuel quantity at destination below required final reserve fuel. |
66 | LOC32 — Incorrect aircraft configuration | Develop means to identify situations of incorrect or unusual aircraft configuration for each phase of the flight | Aircraft upset | 1.3(6) Actual or attempted take-off, approach or landing with incorrect configuration setting |
67 | CFIT01 — Poor visibility conditions | Develop means to identify present visibility conditions (e.g. instrument meteorological conditions or visual meteorological conditions | Collision with terrain | No direct link to a specific type of occurrence |
68 | CFIT02 — Wrong altimeter settings | Develop means to identify wrong altimeter settings | Collision with terrain | 1.4(7) Operation with incorrect altimeter setting |
69 | CFIT03 — Flight below minimum sector altitude | Develop means to identify situations of aircraft that fly below the minimum sector altitude | Collision with terrain | 1.3(9) Continuation of an instrument approach below published minimums with inadequate visual references |
70 | CFIT04 — Deviation below the glideslope | Develop means to identify (severe) deviations below the glideslope that increase the controlled flight into terrain risk | Collision with terrain | 1.3(8) Approach continued against air operator stabilised approach criteria |
71 | CFIT05 — Flight management system incorrectly set | Develop means to identify errors in the flight management system settings, especially those associated with close-to-terrain operations (e.g. approach in a mountainous area) | Collision with terrain | No direct link to a specific type of occurrence |
72 | CFIT06 — Inadequate vertical mode selections of the aircraft flight control system | Develop means to identify inadequate vertical mode selections of the aircraft flight control systems, especially those associated with close-to-terrain operations (e.g. approach in a mountainous area) | Collision with terrain | 1.4(9) Misinterpretation of automation mode or of any flight deck information provided to the flight crew that has or could have endangered the aircraft, its occupants or any other person |
73 | CFIT07 — Incorrect descent point | Develop means to identify incorrect descent points | Collision with terrain | No direct link to a specific type of occurrence |
74 | CFIT08 — Inadequate terrain awareness and warning system (TAWS) escape manoeuvre | Develop means to identify escape manoeuvres after a triggered TAWS alert that are non-compliant with the correct manoeuvre or airline SOPs. Approaches with repeated TAWS soft warnings (or just one TAWS warning) should be monitored. Repeated TAWS soft warnings during an approach can evidence that either the aircraft was not safe with regard to the terrain potentially due to the approach procedure design, or that the TAWS needs to be adjusted for that particular approach | Collision with terrain | 5(3) Activation of genuine ground collision system such as ground proximity warning system (GPWS) / terrain awareness and warning system (TAWS) ‘warning’. |
75 | CFIT09 — Inadequate missed approach and go-around flight path | Develop means to identify missed approach and go-around flight paths that are non-compliant with published information or airline SOPs | Collision with terrain | No direct link to a specific type of occurrence |
76 | CFIT10 — Loss of communication | Develop means to identify loss of communication | Collision with terrain, airborne collision | 3(2) Prolonged loss of communication with air traffic service or air traffic management unit |
77 | CFIT11 — Low-energy state during approach / unstable approach | Develop means to identify low-energy states during approach and unstable approach | Collision with terrain | No direct link to a specific type of occurrence |
78 | CFIT12 — Inadequate response to wind shear warnings | Develop means to detect inadequate response to wind shear warnings, especially in situations close to terrain (e.g. approach in a mountainous area) | Collision with terrain | 5(12) A significant wind shear or thunderstorm encounter that has or could have endangered the aircraft, its occupants or any other person |
79 | CFIT13 — Reduced horizontal distance to terrain | Develop means to identify scenarios of reduced horizontal distance to terrain | Collision with terrain | No direct link to a specific type of occurrence |
80 | CFIT14 — Reduced time to terrain impact | Develop means to identify scenarios of reduced time to terrain impact assuming the aircraft maintains current track and speed | Collision with terrain | No direct link to a specific type of occurrence |
81 | CFIT15 — Low climb gradient | Develop means to identify scenarios of a reduced climb gradient | Collision with terrain | No direct link to a specific type of occurrence |
82 | MAC01 — Incorrect altimeter setting or incorrect transition timing | Develop means to detect incorrect altimeter settings or incorrect transition timing, which could lead to situations of increased mid-air collision risk | Airborne collision | 1.4(7) Operation with incorrect altimeter setting |
83 | MAC02 — Lateral deviation | Develop means to detect situations where the actual flight trajectory deviates from the published, cleared or intended trajectory | Airborne collision | 1.4(5) Unintentional deviation from intended or assigned track of the lowest of twice the required navigation performance or 10 nautical miles |
84 | MAC03 — Flight-level bust | Develop means to identify flight-level busts, that is, situations where the cleared and intended altitude or flight level is overshot during climb or undershot during descent | Airborne collision | 1.4(3) Level bust |
85 | MAC04 — High rate of climb/descent | Develop means to identify climbs and descents with high rates. Due to the trigger logic of airborne collision avoidance system (ACAS) alerts, high rates can lead to the generation of nuisance alerts (see MAC08 ‘Airborne collision avoidance system (ACAS) alerts’) | Airborne collision | No direct link to a specific type of occurrence |
86 | MAC05 — Inadequate use of automation | Develop means to identify situations of inadequate use of automation related to the aircraft trajectory | Airborne collision | 1.4(9) Misinterpretation of automation mode or of any flight deck information provided to the flight crew that has or could have endangered the aircraft, its occupants or any other person |
87 | MAC06 — Automatic altitude control system OFF in reduced vertical separation minima conditions | Develop means to identify situations of inappropriate settings of the automatic altitude control system in reduced vertical separation minima conditions | Airborne collision | No direct link to a specific type of occurrence |
88 | (Reserved) | |||
89 | MAC08 — Airborne collision avoidance system (ACAS) alerts | Monitor all safety-relevant information with respect to the ACAS that is available within the FDM. In particular, resolution advisories should be identified and further investigated in detail | Airborne collision | 5(2) ACAS RA (Airborne Collision Avoidance System, Resolution Advisory) |
90 | MAC09 — Inappropriate airborne collision avoidance system (ACAS) settings | Develop means to monitor the settings of the ACAS and to verify their suitability | Airborne collision | No direct link to a specific type of occurrence |
[applicable from 1 January 2028 — ED Decision 2025/020/R]