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Appendix 1 to ETSO-C117b - EASA Performance Standard for Airborne Wind Shear Warning and Escape Guidance Systems for Transport Aeroplanes

Available versions for ERULES-1963177438-18037

ED Decision 2020/011/R found in: CS-ETSO Amdt 17 - European Technical Standard Orders (Oct 2026)

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###### Appendix 1 to ETSO-C117b – EASA Performance Standard for Airborne Wind Shear Warning and Escape Guidance Systems for Transport Aeroplanes

*ED
Decision
2020/011/R*

1. PURPOSE

This Appendix establishes the minimum performance
standard (MPS) for airborne wind shear warning and escape guidance
systems for transport category aeroplanes.

2. SCOPE

The scope of this Appendix is to provide MPS for
airborne wind shear warning and escape guidance systems for transport
category aeroplanes. All the paragraph references cited herein are in
reference to this Appendix only.

This performance standard applies only to wind
shear warning systems which identify wind shear phenomena by sensing
an encounter with conditions that exceed the threshold values
contained in this performance standard. In addition to wind shear
warning criteria, this performance standard provides criteria that
are applicable to systems that provide optional wind shear caution
alert capabilities. Wind shear escape guidance is provided to assist
the pilot in obtaining the desired flight path during such an
encounter.

3. DEFINITION OF TERMS

a. Airborne wind shear warning system

A device or system which uses various sensor
inputs to identify the presence of wind shear once the phenomenon is
encountered, and provides the pilot with a timely warning. The system
may include both wind shear warning and wind shear caution alerts. A
warning device of this type does not provide escape guidance
information to the pilot to satisfy the criteria for warning and
flight guidance systems.

b. Airborne wind shear warning and escape guidance
system

A device or system which uses various sensor
inputs to identify the presence of wind shear once the phenomenon is
encountered, and provides the pilot with a timely warning and
adequate flight guidance to improve the probability of recovery from
the wind shear encounter. This system may include both wind shear
warning and wind shear caution alerts.

c. Airborne wind shear auto recovery system

A device or system which integrates or couples
autopilot and/or autothrottle systems of the aeroplanes with an
airborne wind shear flight guidance system.

d. Airborne wind shear escape guidance system

A system which provides the crew with flight
guidance information to improve the probability of recovery once a
wind shear phenomenon is encountered.

e. Failure

The inability of a system, subsystem, unit, or
part to perform within the previously specified limits.

f. False warning or caution

A warning or caution which occurs when the wind
shear warning or caution threshold of the system is not exceeded.

g. Nuisance warning or caution

A warning or caution which occurs when a
phenomenon is encountered, such as turbulence, which does not, in
fact, endanger the aeroplane because of the duration of the
subsequent change in the magnitude of the wind shear.

h. Recovery procedure

A vertical flight path control technique that is
used to maximise the potential for a recovery from an inadvertent
encounter with wind shear.

i. Severe wind shear

A wind shear of sufficient intensity and duration
that it exceeds the performance capability of a particular aeroplane
type. This would be likely to cause an inadvertent loss of control or
ground contact if the pilot did not have information available from
an airborne wind shear warning and escape guidance system which meets
the criteria of this ETSO.

j. Wind shear caution alert

An alert that is triggered by increasing
performance conditions, which is set at a wind shear level that
requires immediate crew awareness and probably subsequent corrective
action by the pilot.

k. Wind shear warning alert

An alert that is triggered by decreasing
performance conditions, which is set at a wind shear level that
requires immediate corrective action by the pilot.

4. GENERAL REQUIREMENTS

In addition to the performance requirements
provided in the main text of this Performance Standard and in the
Appendices to ETSO-C117b, the following general requirements and
equipment characteristics are defined below:

a. General standards

The following general requirements shall be met by
all wind shear warning and escape guidance systems:

(1) Airworthiness

The design and manufacture of the airborne
equipment shall provide for installation so as not to impair the
airworthiness of the aeroplane The material shall be of a quality
which experience and/or tests have demonstrated to be suitable and
dependable for use in aeroplane systems. The workmanship shall be
consistent with high-quality aeroplane electromechanical and
electronic component manufacturing practices.

(2) General performance

The equipment shall perform its intended function,
as defined by the manufacturer.

(3) Fire resistance

Except for small parts (such as knobs, fasteners,
seals, grommets and small electrical parts) that would not
significantly contribute to the propagation of fire, all the
materials that are used shall be self-extinguishing. One means to
show compliance with this requirement is contained in Part 25,
Appendix F.

(4) Operation of controls

Controls that are intended for use during flight
shall be designed to minimise errors, and when operated in any
possible combinations and sequences, shall not result in a condition
whose presence or continuation would be detrimental to the continued
performance of the equipment.

(5) Accessibility of controls

Controls that are not normally adjusted in flight
shall not be readily accessible to the operator.

(6) Interfaces

The interfaces with other aeroplane equipment
shall be designed such that the normal or abnormal operation of the
wind shear warning and escape guidance equipment does not adversely
affect the operation of other equipment.

(7) Compatibility of components

If a system component is individually acceptable
but requires calibration adjustments or matching to other components
in the aeroplane for its proper operation, it shall be identified in
a manner that will ensure its performance to the requirements
specified in this ETSO.

(8) Interchangeability

System components which are identified with the
same manufactured part number shall be completely interchangeable.

(9) Control/display capability

A suitable interface shall be provided to allow
data input, data output, and control of the operation of the
equipment. The control/display shall be operable by one person with
the use of only one hand.

(10) Control/display readability

The equipment shall be designed so that all the
displays and controls are readable under all cockpit ambient light
conditions, ranging from total darkness to reflected sunlight, and
are arranged to facilitate the use of the equipment. If limitations
are necessary on equipment installations to ensure that the displays
are readable, they shall be included in the installation
instructions.

(11) Effects of test procedures

The design of the equipment shall be such that the
application of the specified test procedures does not produce a
condition that is detrimental to the performance of the equipment,
except as specifically allowed.

(12) Equipment computational response time

The equipment shall employ suitable update rates
for the computation and display of detection and guidance
information.

(13) Supplemental heating or cooling

If supplemental heating or cooling is required by
system components to ensure that the requirements of this ETSO are
met, they shall be specified by the equipment manufacturer in the
installation instructions.

(14) Self-test capability

The equipment shall employ a self-test capability
to verify the proper operation of the system.

(i) Any manually initiated self-test mode of
operation shall automatically return the system to the normal
operating mode upon completion of a successful test.

(ii) Any automatically activated self-test feature
shall annunciate this mode of operation to the pilot if this feature
activates annunciation lights, aural messages, or displaces the
guidance commands in any way.

(iii) Use of the system self-test feature shall
not adversely affect the performance of operation of other aeroplane
systems.

(iv) A failure of the system to successfully pass
the self-test shall be annunciated.

(15) Independence of warning and escape guidance
functions

Irrespective of whether the warning and escape
guidance functions are in a combined system or are separate systems,
they should be sufficiently independent such that a failure of either
system does not necessarily preclude or inhibit the presentation of
information from the other. A warning system failure shall not result
in any ambiguous or erroneous guidance system mode annunciations.

(16) System reliability

(i) The probability of a false warning being
generated within the wind shear warning system or the wind shear
warning and escape guidance system shall be 1E-4 or less per flight
hour.

(ii) The probability of an unannunciated failure
of the wind shear warning system or the wind shear warning and escape
guidance system shall be 1E 5 or less per flight hour (reserved).

b. Equipment functional requirements — standard
conditions

The equipment shall meet the following functional
requirements:

(1) Mode annunciation

The mode of operation of the wind shear escape
guidance display shall be annunciated to the pilot upon activation of
the escape guidance during a wind shear encounter, and upon reversion
to a different flight guidance mode.

(2) Malfunction/failure indications

The equipment shall indicate:

(i) any inadequacy or absence of primary power;

(ii) equipment failures;

(iii) inadequate or invalid warning or guidance
displays or output signals; and

(iv) inadequate or invalid sensor signals or
sources.

These malfunction/failure indications shall occur
independently of any operator actions. The lack of adequate warning
displays, escape guidance information, or sensor signals or sources
shall be annunciated when compliance with the requirements of this
ETSO cannot be assured.

(3) Wind shear caution alert

If the equipment includes a wind shear caution:

(i) it shall provide an annunciation of increasing
performance shear (updraft, increasing headwind, or decreasing
tailwind) in accordance with the shear intensity curve shown in
Figure 1;

(ii) this caution alert shall display or provide
an appropriate output for display of an amber caution annunciation
dedicated for this purpose. An aural alert may be provided as an
option. The caution display (or output) should remain until the
threshold wind shear condition no longer exists (not less than 3
seconds) or a wind shear warning alert occurs; and

(iii) gust conditions
shall not cause a nuisance caution alert. Turbulence shall not cause
more than one nuisance caution alert per 250 hours (or 3 000 flight
cycles based on 1 hour/flight cycle) of system operation.

(4) Wind shear warning alert

(i) A wind shear warning
alert shall provide an annunciation of decreasing performance shear
(downdraft, decreasing headwind, or increasing tailwind) with a
magnitude that is greater than or equal to that shown in the shear
intensity curve shown in Figure 1.

(ii) This warning alert shall display or provide
an appropriate output for display of a red warning annunciation
labelled ‘wind shear’ dedicated for this purpose. The visual
alert should remain at least until the threshold wind shear condition
no longer exists, or for a minimum of 3 seconds, whichever is
greater. An aural alert shall be provided that annunciates ‘wind
shear’ for 3 aural cycles. The aural alert need not be repeated for
subsequent wind shear warning alerts within the same mode of
operation.

(iii) Gust conditions shall not cause a nuisance
warning alert. Turbulence shall not cause more than 1 nuisance
warning alert per 250 hours (or 3 000 flight cycles based on 1
hour/flight) of system operation.

(5) Wind shear alert with increased approach
sensitivity and reduced take-off sensitivity modes

(i) Increased approach sensitivity mode. If the
system separates the approach and take-off scenarios, the crew may
reduce the shear intensity level in the approach mode to increase the
probability of providing timely wind shear alerts. They may lower the
floor of the shear intensity curve ‘must alert’ curve in Figure 1
from 0.105 to 0.090. If they lower the floor, they may also modify
the turbulence rejection tests in paragraph 4(d)(7)(ii) such that an
alert in this region is not a failure of the turbulence rejection
test.

(ii) Reduced take-off sensitivity mode. If the
system separates the approach and take-off scenarios, the crew may
desensitise the take-off mode to reduce the probability of unwanted
alerts. They may raise the floor of the shear intensity ‘must
alert’ curve in Figure 1 from 0.105 to 0.120.

(iii) Additional reduced take-off sensitivity
mode. Some high performance jet aeroplanes receive unwanted wind
shear alerts after take-off when climbing at high rates through
atmospheric wind gradients. If these unwanted alerts risk
desensitising pilots to wind shear alerting, the crew may tailor the
floor of the shear intensity ‘must alert’ curve in Figure 1 to
reduce these unwanted alerts under the following conditions:

(a) The airborne wind shear warning and escape
guidance system can determine that the aeroplane is in the take-off
versus approach phase.

(b) The aeroplane is climbing at a high rate of
climb, the aeroplane continues to climb at a high rate, and the rate
of climb is known to create unwanted wind shear alerts.

(c) The aeroplane power setting is at or near a
level that is representative of the maximum for the segment of the
take-off; for example, maximum take-off thrust.

(d) The Figure 1 shear intensity ‘must alert’
curve shall be complied with after take-off.

(6) Alerting prioritisation

If alerting is prioritised in the presentation for
a wind shear warning and escape guidance system (reactive wind
shear), forward-looking wind shear system, terrain awareness and
warning system, ground proximity warning system, traffic collision
avoidance system, or when a simultaneous aural annunciation could
occur, sequencing shall be implemented that ensures that reactive
wind shear warning alerts are presented or annunciated first.
Reactive wind shear alerts that are cautions have a lower priority
than all terrain awareness and warning or ground proximity warning
system alerts.

(7) The reactive wind shear systems caution alert
should be disabled if a forward looking wind shear system is in
operation. It is acceptable to issue reactive wind shear caution
alerts if the forward-looking wind shear system is inoperative.

(8) Operating altitude range

The system shall be designed to function from at
least 50 feet above ground level (AGL) to at least 1 000 feet AGL.

(9) Wind shear escape guidance

Flight guidance algorithms shall incorporate the
following design considerations:

(i) At the point of the system warning threshold,
the available energy of the aeroplane shall be properly managed
through a representative number of wind field conditions. These
conditions shall take into account significant shear components in
both the horizontal and vertical axes, individually and in
combination.

(ii) The flight path guidance commands shall be
suitable for the dynamic response of aeroplane of the type on which
the system is intended for installation. The applicant shall
demonstrate that the flight guidance commands during a dynamic wind
shear encounter can be followed without resulting in pilot induced
oscillations.

(iii) If the magnitude of the shear components is
such as to overcome the performance capability of the aeroplane,
guidance commands shall be such that a ground impact will occur in
the absence of the ability to produce additional lift, an absence of
excessive kinetic energy, and without putting the aeroplane into a
stalled condition.

(iv) Flight guidance command information shall be
provided for presentation on the primary flight display/attitude
direction indicator (PFD/ADI) and any available head-up display
(HUD).

(v) Flight guidance displays which command the
flight path and pitch attitude should be limited to an angle of
attack that is equivalent to the onset of a stall warning or a
maximum pitch command of 27°, whichever is less.

(vi) Flight guidance commands and any auto
recovery mode (if included) may be automatically activated
concurrently with or after the wind shear warning alert occurs, or
may be manually selected. If manual selection is utilised, it shall
only be via the take-off/go-around (TOGA) switch or equivalent means
(i.e. a function of the throttle position, other engine parameters,
etc.).

(vii) Manual deselection of wind shear flight
guidance and any auto recovery mode (if included) shall be possible
by means other than the TOGA switches.

(viii) Systems that incorporate the automatic
reversion of flight guidance commands from wind shear escape guidance
to another flight guidance mode should provide a smooth transition
between the modes. Flight guidance commands shall not be removed from
the flight guidance display until either they are manually deselected
or until the aeroplane, following the end of the warning conditions,
has maintained a positive rate of climb and speed above 1.3 Vs1 for
at least 30 seconds.

***FIGURE
1 — SHEAR INTENSITY CURVE***

![](/static/files/file_jytjXw2lpRK/image037.png)

fav,x = average shear intensity to cause a warning at time
tx (resulting in a 20-knot wind speed change, bounded as
shown; applies to horizontal, vertical, and combination shear
intensities),

whereby f(*t*) = instantaneous shear intensity at time *t*.

![](/static/files/file_jytjXw2lpRK/image039.png)

c. Equipment performance —
environmental conditions

(1) The environmental tests and performance requirements described in
this subsection are intended to provide a laboratory means to
determine the overall performance characteristics of the equipment
under conditions that are representative of those that may be
encountered in actual operations. Table 1 defines the environmental
tests that are required for the equipment. It shows the section
numbers in ED-14G that describe the individual environmental tests.
Some of the environmental tests contained in this subsection do not
need to be performed unless the manufacturer wishes to qualify the
equipment for that particular environmental condition. These tests
are identified by the phrase ‘When required’ in Table 1. If the
manufacturer wishes to qualify the equipment to these additional
environmental conditions, then these ‘When required’ tests shall
be performed.

(2) Environmental requirements. The following subset of performance
requirements shall be met under the environmental conditions required
by paragraph 3.1.2 of this ETSO. Additionally, all the system
controls, displays, inputs and outputs shall perform their intended
functions when subjected to the ED-14G environmental conditions.

(i) Section 4.b(1) — Mode Annunciation

(ii) Section 4.b(2) — Malfunction/Failure Indications

(iii) Section 4.b(3) — Wind Shear Caution Alert, except paragraph
4.b(3)(iii)

(iv) Section 4.b(4) — Wind Shear Warning Alert, except paragraph
4.b(4)(iii)

(v) Section 4.b(5) — Wind Shear Alert with Increased Approach
Sensitivity and Reduced Take-off Sensitivity Modes

(vi) Section 4.b(9) — Wind Shear Escape Guidance

(3) The applicant shall conduct environmental qualification tests for
the following shear intensity (fav,x) and exposure time
(s) in Figure 1: 0.1050, 10; 0.1748, 6; and 0.2100, 5; and ensure
that the system generates and displays alerts when required. A single
representative wind shear waveform may be used for all the
environmental tests if the system design is such that different
waveforms will not affect the performance under environmental
conditions. Gust and turbulence rejection tests are not required
under environmental conditions.

***Table
1 — Required EUROCAE ED-14G Testing by Category***

<table bgcolor="#d9d9d9" cellpadding="7" cellspacing="0">
<col/>
<col/>
<col/>
<tr valign="top">
<td bgcolor="#808080">
Environmental
				Test 

</td>
<td bgcolor="#808080">
ED-14G
				Section
</td>
<td bgcolor="#808080">
Required
				Test
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Temperature
				and Altitude 

</td>
<td bgcolor="#d9d9d9">
4
</td>
<td bgcolor="#d9d9d9">
 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Ground
				Survival Low Temperature and Short-Time Operating Low Temperature
				

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Low
				Operating Temperature 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Ground
				Survival High Temperature and Short-Time Operating High
				Temperature 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
High
				Operating Temperature 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
In-Flight
				Loss of Cooling 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Altitude
				

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Decompression
				

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Overpressure
				

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Temperature
				Variation 

</td>
<td bgcolor="#d9d9d9">
5
</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Humidity
				

</td>
<td bgcolor="#d9d9d9">
6
</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Operational
				Shocks and Crash Safety 

</td>
<td bgcolor="#d9d9d9">
7
</td>
<td bgcolor="#d9d9d9">
 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Operational
				Shocks 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Crash
				Safety 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Vibration
				

</td>
<td bgcolor="#d9d9d9">
8
</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Explosion
				Proofness 

</td>
<td bgcolor="#d9d9d9">
9
</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Waterproofness
				

</td>
<td bgcolor="#d9d9d9">
10
</td>
<td bgcolor="#d9d9d9">
 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Condensing
				Water Proof 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Drip
				Proof 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Spray
				Proof 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Continuous
				Stream Proof 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Fluids
				Susceptibility 

</td>
<td bgcolor="#d9d9d9">
11
</td>
<td bgcolor="#d9d9d9">
 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Spray
				

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Immersion
				

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Sand
				and Dust 

</td>
<td bgcolor="#d9d9d9">
12
</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Fungus
				Resistance 

</td>
<td bgcolor="#d9d9d9">
13
</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Salt
				Spray 

</td>
<td bgcolor="#d9d9d9">
14
</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Magnetic
				Effect 

</td>
<td bgcolor="#d9d9d9">
15
</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Power
				Input 

</td>
<td bgcolor="#d9d9d9">
16
</td>
<td bgcolor="#d9d9d9">
 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Normal
				Operating Conditions (AC/DC) 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Abnormal
				Operating Conditions (AC/DC) 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Load
				Equipment Influence on Aeroplane Electrical Power System (AC/DC) 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Voltage
				spike 

</td>
<td bgcolor="#d9d9d9">
17
</td>
<td bgcolor="#d9d9d9">
 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Category
				A Requirements (If applicable) 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Category
				B Requirements (If applicable) 

</td>
<td bgcolor="#d9d9d9">
 

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Audio
				frequency conducted susceptibility 

</td>
<td bgcolor="#d9d9d9">
18
				

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Induced
				Signal Susceptibility 

</td>
<td bgcolor="#d9d9d9">
19
				

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
RF
				Susceptibility 

</td>
<td bgcolor="#d9d9d9">
20
				

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Emission
				of RF Energy 

</td>
<td bgcolor="#d9d9d9">
21
				

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Lightning-induced
				Transient Susceptibility 

</td>
<td bgcolor="#d9d9d9">
22
				

</td>
<td bgcolor="#d9d9d9">
				√ 
				
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Lightning
				Direct Effects 

</td>
<td bgcolor="#d9d9d9">
23
				

</td>
<td bgcolor="#d9d9d9">
When
				required 

</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Icing
</td>
<td bgcolor="#d9d9d9">
24
</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Electrostatic
				Discharge
</td>
<td bgcolor="#d9d9d9">
25
</td>
<td bgcolor="#d9d9d9">
When
				required
</td>
</tr>
<tr valign="top">
<td bgcolor="#d9d9d9">
Fire,
				Flammability 

</td>
<td bgcolor="#d9d9d9">
26
</td>
<td bgcolor="#d9d9d9">
				√
</td>
</tr>
</table>

d. Equipment test procedures

(1) Definitions of terms and conditions of tests. The following
definitions of terms and conditions of tests are applicable to the
equipment tests specified herein:

(i) Power input voltage. Unless otherwise specified, all the tests
shall be conducted with the power input voltage adjusted to the
design voltage ± 2 per cent. The input voltage shall be measured at
the input terminals of the equipment under test.

(ii) Power input frequency

(a) In the case of equipment that is designed for operation from an
AC power source of essentially constant frequency (e.g. 400 Hz), the
input frequency shall be adjusted to the design frequency ± 2 per
cent.

(b) In the case of equipment designed for operation from an AC power
source of variable frequency (e.g. 300 to 1 000 Hz), unless otherwise
specified, the test shall be conducted with the input frequency
adjusted to within 5 % of a selected frequency and within the range
for which the equipment is designed.

(iii) Wind field models. Unless otherwise specified, the wind field
models used for the tests shall be those specified in Appendix 2 to
ETSO-C117b.

(iv) Adjustment of equipment. The circuits of the equipment under
test shall be aligned and adjusted in accordance with the
manufacturer’s recommended practices prior to the application of
the specified tests.

(v) Test instrument precautions. Due precautions shall be taken
during the execution of the tests to prevent the introduction of
errors that result from the connection of voltmeters, oscilloscopes,
and other test instruments across the input and output impedances of
the equipment under test.

(vi) Ambient conditions. Unless otherwise specified, all the tests
shall be made within the following ambient conditions:

— Temperature: + 15 to + 35 °C (+ 59 to + 95 °F)

— Relative humidity: Not greater than 85 %

— Ambient pressure: 84–107 kPa (equivalent to + 5 000 to – 1
500 ft) (+ 1 525 to – 460 m)

(vii) Warm-up period. Unless otherwise specified, all the tests shall
be conducted after the manufacturer’s specified warm-up period.

(viii) Connected loads. Unless otherwise specified, all the tests
shall be performed with the equipment connected to loads which have
the impedance values for which it is designed.

(2) Test procedures. The equipment shall be tested in all the modes
of operation that allow different combinations of sensor inputs to
show that it meets both the functional and accuracy criteria.

Dynamic testing provides quantitative data regarding the performance
of wind shear warning and escape guidance equipment using a
simplified simulation of flight conditions. This testing, when
properly performed and documented, may serve to minimise the flight
test requirements.

It shall be the responsibility of the equipment manufacturer to
determine that the sensor inputs, when presented to the wind shear
warning and escape guidance equipment, will produce performance that
is commensurate with the requirements of this standard. Additional
sensor inputs may be optionally provided to enhance the capability
and/or performance of the equipment.

The equipment required to perform these tests shall be defined by the
equipment manufacturer as a function of the specific sensor
configuration of the equipment. Since these tests may be accomplished
in more than one way, alternative test equipment set ups may be used
where equivalent test functions can be accomplished. Combinations of
tests may be used wherever appropriate.

The signal sources of the test equipment shall provide the
appropriate signal formats for input to the specific system under
test without contributing to the error values that are being
measured. Tests need only be performed once, unless it is otherwise
indicated.

The scenarios that are established for testing wind shear warning and
escape guidance systems represent realistic operating environments to
properly evaluate such systems. The wind field models contained in
Appendix 2 to ETSO C117b should be used to evaluate the performance
of the wind shear warning and escape guidance systems. The
manufacturer may propose different wind field models provided that it
is shown that they represent conditions that are at least as severe
as those contained in this ETSO.

Note: The test waveform parameters provided in this ETSO are
sufficiently broad to cover the wind field parameters that were
observed in the known accident cases. However, the manufacturer is
encouraged to verify that the detection systems will actually detect
these wind shears by subjecting them to the wind field conditions
specified for use in evaluating guidance commands.

(3) Test set-up. Simulator tests shall be used to demonstrate the
performance capability of the wind shear warning and escape guidance
equipment. A suitable equipment interface shall be provided for
recording the relevant parameters that are necessary to evaluate the
particular system under test. The aeroplane simulator shall be
capable of appropriate dynamic modelling of a representative
aeroplane and of the wind field and turbulence conditions contained
in Appendices 2 and 3 to this ETSO, or other wind field/turbulence
models that are found to be acceptable by the administrator.

Note: This section requires testing in a single representative
aeroplane simulator. Approval of the installation will require system
testing in an aeroplane simulator that is representative of the
aeroplane. Thus, we recommend you to accomplish the paragraph 4(d)(3)
simulator testing in as many representative simulators as are
necessary to cover all the intended installations.

(4) Functional performance (paragraphs 4(b)(1) through 4(b)(5),
4(b)(8) and 4(b)(9)). Each of the functional capabilities identified
in paragraphs 4(b)(1) through 4(b)(5), 4(b)(7) and 4(b)(8) shall be
demonstrated with the wind shear warning and escape guidance
equipment powered. These capabilities shall be evaluated either by
inspection or in conjunction with the tests described in paragraphs
4(d)(5) through 4(d)(10).

(5) Mode annunciation (paragraph 4(b)(1)). With the equipment
operating, verify that the wind shear escape guidance display mode of
operation is annunciated to the pilot upon activation of the escape
guidance and upon reversion to a different flight guidance mode.

(6) Malfunction/failure indications (paragraph 4(b)(2)). Configure
the equipment for simulation tests as defined in paragraph 4(d)(3).

(i) With the system active (within the operating altitude range) and
inactive (outside the operating altitude range), remove one at a time
each required electrical power input to the equipment. There shall be
a failure indication by the equipment of each simulated failure
condition.

(ii) With the system active (within the operating altitude range) and
inactive (outside the operating altitude range), cause each sensor or
other signal input to become inadequate or invalid. There shall be a
failure indication by the equipment of each simulated failure
condition.

(7) Wind shear caution alert (paragraphs 4(b)(3) and 4(b)(5)(i)). For
equipment that incorporates a wind shear caution alert function,
accomplish the following tests:

(i) Configure the equipment for a simulation test as defined in
paragraph 4(d)(3). Subject the equipment to acceleration waveform
values that meet the following conditions (reference Figure 2). The
system shall generate an appropriate caution alert (or no alert)
within the time intervals specified when subjected to the following
average shear intensity (fav,x) values:

<table cellpadding="7" cellspacing="0">
<col/>
<col/>
<col/>
<tr valign="top">
<td>
fav,x
				(1)
</td>
<td>
Time
				of Exposure (t) (s)
</td>
<td>
Alert
				within (s) (3)
</td>
</tr>
<tr valign="top">
<td>
0.0200
</td>
<td>
20
</td>
<td>
no
				alert
</td>
</tr>
<tr valign="top">
<td>
0.0400
</td>
<td>
20
</td>
<td>
no
				alert
</td>
</tr>
<tr valign="top">
<td>
0.1050
</td>
<td>
10
</td>
<td>
10
</td>
</tr>
<tr valign="top">
<td>
0.1166
</td>
<td>
9
</td>
<td>
9
</td>
</tr>
<tr valign="top">
<td>
0.1311
</td>
<td>
8
</td>
<td>
8
</td>
</tr>
<tr valign="top">
<td>
0.1499
</td>
<td>
7
</td>
<td>
7
</td>
</tr>
<tr valign="top">
<td>
0.1748
</td>
<td>
6
</td>
<td>
6.2
</td>
</tr>
<tr valign="top">
<td>
0.2100
</td>
<td>
5
</td>
<td>
5.7
</td>
</tr>
<tr valign="top">
<td>
0.2700
				(2)
</td>
<td>
5
</td>
<td>
5
</td>
</tr>
</table>

Notes:

(1) The average shear intensity which shall result in a caution alert
after a time tx or less meets the definition of fav,x in Figure 1.
The maximum instantaneous shear intensity of the test waveform is
restricted to 0.075 or 100 % of fav,x above the average shear
value fav,x, whichever is less. The minimum instantaneous shear
intensity of the test waveform is zero. The test waveform rise and
fall rates shall be limited to a maximum of 0.1 per second. The shear
intensity before time 0 is zero for a sufficiently long time to allow
the system to settle to stable conditions.

(2) In order to achieve the test condition with the shear intensity
fav,x equal to or greater than 0.270, it is necessary to have an
initial rise of sufficient rate to achieve a shear intensity f value
that will allow subsequent rise and fall rates that are limited to
0.1 per second to achieve the required fav,x value.

(3) Account for latency due to the alert calculation and alert
annunciation display functionality when measuring the alert time

The test conditions specified above shall be repeated 5 times for
each axis (horizontal and vertical). A total of 90 runs are required
for verification of the detection (9 conditions × 5 for each axis)
for both performance increasing and performance decreasing wind
shears. A different waveform for fav,x will be utilised for each of
the 5 runs. An appropriate alert (or no alert) shall be generated for
each test condition.

Verify that the system displays or provides an appropriate output for
display of an amber caution annunciation that is dedicated for this
purpose. Verify that the visual caution display (or output) remains
at least until the threshold wind shear condition no longer exists,
or a minimum of 3 seconds (whichever is greater), or until a wind
shear warning occurs.

(ii) Subject the equipment to wind speeds that are defined by the
Dryden turbulence model contained in Appendix 4 to ETSO C117b. The
system shall be exposed to these conditions for a minimum of 50 hours
(or 600 flight cycles) at each altitude specified in Appendix 4 to
ETSO C117b for a minimum total test duration of 250 hours (or 3 000
flight cycles based on 1 hour/flight cycle).

No more than 1 nuisance caution shall be generated during this test.

An alternative test equipment set-up may be used to accomplish the
equivalent test function for the turbulence testing. A combination of
analysis, simulation and testing may be used to demonstrate the
performance of the equipment.

(iii) Subject the equipment to the wind speeds that are defined by
the discrete gust rejection model contained in Appendix 4 to ETSO
C-117b. No alert shall be generated as a result of this test.

(8) Wind shear warning alert (paragraphs 4(b)(4) and 4(b)(5)(ii)).

(i) Configure the equipment for simulation tests as defined in
paragraph 4(d)(3). Subject the equipment to acceleration waveform
values that meet the following conditions (reference Figure 2). The
system shall generate an appropriate warning alert (or no alert)
within the time intervals that are specified when it is subjected to
the following average shear intensity (fav,x) values:

<table cellpadding="7" cellspacing="0">
<col/>
<col/>
<col/>
<tr valign="top">
<td>
fav,x
				(1)
</td>
<td>
Time
				of Exposure (t) (s)
</td>
<td>
Alert
				within (s) (3)
</td>
</tr>
<tr valign="top">
<td>
0.0200
				

</td>
<td>
20
				

</td>
<td>
no
				alert 

</td>
</tr>
<tr valign="top">
<td>
0.0400
				

</td>
<td>
20
				

</td>
<td>
no
				alert 

</td>
</tr>
<tr valign="top">
<td>
0.1050
				

</td>
<td>
10
				

</td>
<td>
10
				

</td>
</tr>
<tr valign="top">
<td>
0.1166
				

</td>
<td>
9
				

</td>
<td>
9
				

</td>
</tr>
<tr valign="top">
<td>
0.1311
				

</td>
<td>
8
				

</td>
<td>
8
				

</td>
</tr>
<tr valign="top">
<td>
0.1499
				

</td>
<td>
7
				

</td>
<td>
7
				

</td>
</tr>
<tr valign="top">
<td>
0.1748
				

</td>
<td>
6
				

</td>
<td>
6.6
				

</td>
</tr>
<tr valign="top">
<td>
0.2100
				

</td>
<td>
5
				

</td>
<td>
6.2
				

</td>
</tr>
<tr valign="top">
<td>
0.2700
				(2) 

</td>
<td>
5
				

</td>
<td>
5.7
				

</td>
</tr>
</table>

Notes:

(1) The average shear intensity which shall result in a warning alert
after a time tx or less meets the definition of fav,x in Figure 1.
The maximum instantaneous shear intensity of the test waveform is
restricted to 0.075 or 100 % of fav,x above the average shear
value fav,x , whichever is less. The minimum instantaneous shear
intensity of the test waveform is zero. The test waveform rise and
fall rates shall be limited to a maximum of 0.1 per second. The shear
intensity before time 0 is zero for a sufficiently long time to allow
the system to settle to stable conditions.

(2) In order to achieve the test condition with the shear intensity
fav,x equal to or greater than 0.270, it is necessary to have an
initial rise of a sufficient rate to achieve a shear intensity f
value that will allow the subsequent rise and fall rates that are
limited to 0.1 per second to achieve the required fav,x value.

(3) Account for any latency due to the alert calculation and alert
annunciation display functionality when measuring the alert time.

Verify that the system displays or provides an appropriate output for
display of a red warning annunciation labelled ‘wind shear’ that
is dedicated for this purpose. Verify that the visual warning display
(or output) remains until the threshold wind shear condition no
longer exists, or a minimum of 3 seconds, whichever is greater.
Verify that an aural alert is provided that annunciates ‘wind
shear’ for 3 aural cycles.

(ii) Subject the equipment to the wind speeds that are defined by the
Dryden turbulence model contained in Appendix 4 to ETSO C117b. The
system shall be exposed to these conditions for a minimum of 50 hours
(or 600 flight cycles) at each altitude specified in Appendix 4 to
ETSO C117b for a minimum total test duration of 250 hours (or 3 000
flight cycles based on 1 hour/flight cycle). No more than 1 nuisance
warning shall be generated during this test.

An alternative test equipment set-up may be used to accomplish the
equivalent test function for the turbulence testing. A combination of
analysis, simulation, and testing may be used to demonstrate the
performance of the equipment specified in this paragraph 4(d)(8)(ii).

(iii) Subject the equipment to the wind speeds that are defined by
the discrete gust rejection model contained in Appendix 4 to
ETSO-C117b. No alerts shall be generated as a result of this test.

***FIGURE
2 — WIND SHEAR ALERT TEST***

![](/static/files/file_jytjXw2lpRK/image040.png)

(9) Operating altitude range (paragraph 4.b(8)). Configure the
equipment for the simulation tests as defined in paragraph 4(d)(3).
Simulate a take-off to an altitude of at least 1 500 feet AGL. Verify
the wind shear warning and escape guidance system is operational from
at least 50 feet AGL to at least 1 000 feet AGL. Simulate an approach
to landing from 1 500 feet AGL to touchdown. Verify the wind shear
warning and escape guidance system is operational from at least 1 000
feet AGL to at least 50 feet AGL.

(10) Wind shear escape guidance (paragraph 4.b(9)). Configure the
equipment for simulation tests as defined in paragraph 4(d)(3).
Subject the equipment to each of the wind field conditions contained
in Appendix 2 to ETSO C117b for each operating mode (take-off,
approach, landing, etc.) that is available. Each test condition shall
be repeated 5 times. Recovery actions for the fixed pitch method
comparison shall be initiated immediately upon entering the shear
condition.

Notes:

(1) Evaluate wind shear escape guidance commands using a simulation
that incorporates the necessary dynamic modelling of the
representative aeroplane (more than 1 representative aeroplane model
may be necessary) in which installation of the equipment is intended.
Dynamic modelling of the representative aeroplane should include
consideration of all the relevant effects, including but not limited
to pitch and roll rates, control authority, delays between control
inputs and aeroplane responses, display system leads and lags, etc.

(2) The simulator should provide for a pilot in the loop evaluation
of guidance flyability during simulated wind shear encounters. The
guidance command gains should be consistent with those incorporated
in the flight guidance system. While ‘fine-tuning’ of the
guidance commands to obtain the optimum performance for a specific
aeroplane may be accomplished, the use of unique tailoring for a
specific aeroplane may not be necessary. Evaluation through means of
a suitable engineering simulation may be acceptable to demonstrate
the suitability of the guidance commands for a representative
aeroplane. However, the equipment manufacturer should demonstrate
that the flight guidance commands during a dynamic wind shear
encounter can be followed without resulting in pilot-induced
oscillations.

(i) Verify that the flight path guidance commands manage the
available energy of the aeroplane to achieve the desired trajectory
through the shear encounter. These tests shall be performed with
vertical only, horizontal only, and a combination of vertical and
horizontal shear conditions. You may reduce the number of times you
repeat each of these tests conditions to less than 5. To reduce the
number of repetitions to less than 5, you shall have gathered
sufficient data to demonstrate that the flight path guidance commands
meet these requirements. You should also include aeroplane weight and
centre of gravity variations if applicable.

a. For the take-off case, verify that the flight guidance commands
produce a trajectory that provides a resultant flight path that is at
least as good (when considered over the entire spectrum of test
cases) as that obtained by establishing a 15° pitch attitude (at an
approximate rate of 1.5° per second) until the onset of a stall
warning, and then reducing the pitch attitude to remain at the onset
of a stall warning until the shear condition is exited. Evidence of a
significant decrement (considered over the entire spectrum of test
cases) below the flight path that is provided by the fixed pitch
method that results from the use of the guidance commands provided by
the system shall be adequately substantiated.

b. For the approach/landing case, verify that the flight guidance
commands produce a trajectory that provides a resultant flight path
that is at least as good (when considered over the entire spectrum of
test cases) as that obtained by establishing the maximum available
thrust and a 15° pitch attitude (at an approximate rate of 1.5° per
second) until the onset of stall warning, and then reducing the pitch
attitude to remain at the onset of stall warning until the shear
condition is exited. Evidence of a significant decrement (considered
over the entire spectrum of test cases) below the flight path that is
provided by the fixed pitch method that results from the use of the
guidance commands that are provided by the system shall be adequately
substantiated.

c. For shear conditions that exceed the available performance
capability of the aeroplane, verify that the flight guidance commands
result in a ground impact in the absence of the ability to produce
additional lift, an absence of excessive kinetic energy, and without
putting the aeroplane into a stalled condition.

Note: There is no requirement to perform the tests described in
paragraphs 4(d)(10)(ii) through (vii) with horizontal only, vertical
only, and a combination of vertical and horizontal shear conditions.
You may perform the tests described in paragraphs 4(d)(10)(ii)
through (vii) with only the combination vertical and horizontal shear
conditions.

(ii) Verify that the flight guidance command outputs are capable of
display on the associated flight displays. The interface
specifications shall be verified and determined to be appropriate for
the systems that are identified in the equipment installation
instructions.

(iii) Verify that the pitch attitude commands do not result in an
angle of attack that exceeds the onset of a stall warning or a
maximum pitch command of 27°, whichever is less.

(iv) For systems that incorporate manual activation of recovery
flight guidance commands, verify that the system is activated only by
the TOGA switches (or equivalent means). For systems that provide
automatic activation of recovery guidance, verify that the system is
activated concurrently with the wind shear warning alert.

(v) Verify that the wind shear recovery guidance commands and any
automatic recovery mode can be deselected by a means other than the
TOGA switches.

(vi) For systems that incorporate automatic reversion of flight
guidance commands from wind shear escape guidance to another flight
guidance mode, verify that the transition between the flight guidance
modes provides smooth guidance information.

(vii) Verify that flight guidance commands are not removed from the
flight guidance display until either they are manually deselected or
until the aeroplane, following the exit of the warning conditions,
has maintained a positive rate of climb and speed above 1.3 Vs1 for
at least 30 seconds.

[Amdt ETSO/16]