What data should be recorded by the accident data recording system from the TAWS?

The accident data recording system should record alerts from the TAWS and, where practicable, when FLTA or PDA is inhibited.

What altitude is generally acceptable for TAWS voice call-outs according to AMC1 ACNS.E.TAWS.010?

A predetermined altitude of 150 m (500 ft) is generally acceptable for TAWS voice call-outs. However, another altitude may be allowed if a call-out at 150 m (500 ft) would interfere with other operations.

AMC1 ACNS.E.TAWS.010 Required functions

Q: How do TAWS Class B equipment determine the altitude for voice callouts?

For Class B equipment, the predetermined altitude voice callout is based upon barometric height above runway elevation.

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ED Decision 2022/008/R

Note: An example of an acceptable TAWS installation is provided in Appendix B – Example of an acceptable TAWS installation. Guidance on testing a TAWS is provided in Appendix A – TAWS installations testing guidance material.

(a) For the voice call-out, a predetermined altitude of 150 m (500 ft) has been found acceptable. However, another altitude may be allowed when a call-out at 150 m (500 ft) would interfere with other operations.

(b) For Class B equipment the predetermined altitude voice callout is based upon barometric height above runway elevation.

Note: The nearest runway elevation may be used for this purpose.

(c) TAWS equipment may compute Barometric Altitude Rate using an Instantaneous Vertical Speed Indicator (IVSI) or an inertial smoothed vertical speed indicator. An alternative means, with demonstrated equal or better accuracy, may be used in lieu of barometric altitude rate (accuracy specified in ETSO-C10b, Altimeter, Pressure Actuated, Sensitive Type, or later revisions) and/or altimeter altitude (accuracy specified in ETSO-2C87 (Low range radio altimeters) - or later revisions) to meet the warning requirements described in RTCA Document No. DO-161A. In addition, ETSO-C106 for Air Data Computers may be used as an alternative means of compliance with this provision.

(d) An interface with the accident data recording system to record alerts from the TAWS and to record, where practicable, when FLTA or PDA is inhibited.

Note 1: It is not necessary to be able to distinguish between the Basic GPWS and the new FLTA and/or PDA alerts from the recording. The voice recorder will be used for this purpose.

Note 2: Where the data recorded by the Flight Data Recorder is modified, the document which presents the information necessary to retrieve and convert the stored data into engineering units, will need to be amended by the operator.

[Issue: CS-ACNS/4]

Details

Source-Title: AMC1 ACNS.E.TAWS.010 Required functions View latest amendments

Erulesid: ERULES-1963177438-15784 Compare versions

Domain: Air traffic management/Air navigation services

Amendedby: CS Issue 4

Applicabilitydate: 6 April, 2022

Entryintoforcedate: 6 April, 2022

Regulatorysource: ED Decision 2022/008/R Navigate

Regulatorysubject: CS-ACNS

Typeofcontent: AMC to CS (Acceptable means of compliance to certification specification)

Parentir: CS ACNS.E.TAWS.010 Required Functions and Interfaces

Origin: EASA

Category: EAR