**Executive Summary**
This Civil Aviation Requirement (CAR) document, effective immediately, outlines revised requirements for the installation and use of Ground Proximity Warning Systems (GPWS) based on amendments to ICAO Annex 6 and Indian experience with Controlled Flight Into Terrain (CFIT) problems. It specifies equipment mandates for different categories of aeroplanes and outlines operational requirements. Certain aeroplanes with a certificate of airworthiness first issued on or after January 1, 2026 have specific requirements.
**Key Points / Main Content**
* **Equipment Requirements:**
* Turbine-engined aeroplanes exceeding 5700 kg or carrying more than nine passengers must have GPWS with forward-looking terrain avoidance.
* Turbine-engined aeroplanes of 5700 kg or less, carrying between six and nine passengers must have GPWS that provides warnings of unsafe terrain clearance and forward-looking terrain avoidance.
* Turbine-engined aeroplanes of 5700 kg or less, carrying between six and nine passengers with a certificate of airworthiness first issued on or after January 1, 2026, must have GPWS that provides warnings of unsafe terrain clearance and forward-looking terrain avoidance.
* Piston-engined aeroplanes exceeding 5700 kg or carrying more than nine passengers must have GPWS that provides warnings of unsafe terrain clearance and forward-looking terrain avoidance.
* **Operational Requirements:**
* GPWS must provide warnings for excessive descent rate, excessive terrain closure rate, excessive altitude loss after take-off/go-around, unsafe terrain clearance, and excessive descent below the instrument glide path.
* Aeroplane flight manuals must include procedures for GPWS use, checklists, flight crew actions, deactivation for planned conditions, and mode 4 warning inhibition.
* GPWS deactivation is only permitted according to procedures in the aeroplane flight manual and must be recorded in the maintenance record.
* Operators are encouraged to consider additional warning modes for enhanced safety.
* Turbine-jet aeroplanes exceeding 5700 kg or carrying more than nine passengers may be equipped with forward-looking wind shear warning systems.
* **General Requirements:**
* GPWS must be of an approved type and meet specific technical standards (FAA TSO C-92 C or equivalent).
* Installation must be performed by an approved organization and maintained in serviceable condition.
* Engineers must hold appropriate licenses and training.
* Operations Manuals must be amended to reflect changes in operating procedures.
* **Database Management:**
* Operators must implement procedures for timely distribution and updates of terrain and obstacle data to the GPWS.
**Impact Analysis**
**Stakeholder: Aeroplane Operators**
* **Impact:** Must ensure aircraft are equipped with compliant GPWS and/or EGPWS based on aircraft type, passenger capacity and date of first airworthiness certificate issuance. Affected by operational procedure requirements and database management requirements.
* **Action Required:** Review aircraft fleet, procure and install compliant GPWS, update flight manuals and operating procedures, implement database management procedures.
**Stakeholder: Flight Crews**
* **Impact:** Must adhere to updated procedures for GPWS use and responses to warnings.
* **Action Required:** Familiarize themselves with updated flight manual procedures and GPWS operation.
**Stakeholder: Maintenance Personnel**
* **Impact:** Must maintain GPWS in serviceable condition according to approved procedures.
* **Action Required:** Obtain appropriate training and licensing for GPWS maintenance.
**Stakeholder: DGCA**
* **Impact:** Responsible for ensuring compliance with this CAR.
* **Action Required:** Oversee compliance and potentially update processes for certification and approvals.
Key Entities Referenced
Ground Proximity Warning System (GPWS): An equipment installed in an aeroplane for the purpose of providing automatically a timely and distinctive warning to the flight crew when the aeroplane is in potentially hazardous proximity to the earth's surface.
Aircraft Rules, 1937: Rule 57 and 133A are referenced for the installation and issuing of the Civil Aviation Requirements.
CIVIL AVIATION REQUIREMENTS: Document outlining the revised requirements for installation of GPWS.
ICAO Annex 6: The document refers to amendments in ICAO Annex 6 regarding GPWS.
Director General of Civil Aviation: Issuer of Civil Aviation Requirements.
GOVERNMENT OF INDIA
OFFICE OF THE DIRECTOR GENERAL OF CIVIL AVIATION
TECHNICAL CENTRE, OPP SAFDURJUNG AIRPORT, NEW DELHI
CIVIL AVIATION REQUIREMENTS
SECTION 2 - AIRWORTHINESS
SERIES 'I', PART VII
th
28 MAY, 1999 EFFECTIVE: FORTHWITH
F. No. DGCA-25012(07)/7/2021-AW
SUBJECT: GROUND PROXIMITY WARNING SYSTEM (GPWS).
1 INTRODUCTION
ICAO introduced Ground Proximity Warning System (GPWS) carriage
requirements in 1978 to alleviate the Controlled Flight Into Terrain (CFIT)
problem. A significant decline in the number of incidents was observed after
installation of GPWS. The CFIT, however, continued to be a critical flight safety
problem. ICAO has, therefore, amended the GPWS provisions in Annex 6. This
issue of CAR brings out the revised requirements for installation of GPWS
keeping in view the amendments to Annex 6 issued by ICAO and also the Indian
experience of CFIT problem.
Rule 57 of the Aircraft Rules, 1937 stipulates that every aircraft shall be fitted
and equipped with instruments and equipment, including radio apparatus and
special equipment, as may be specified according to the use and circumstances
under which the flight is to be conducted. This CAR is issued under the
provisions of Rule 133A of the Aircraft Rules, 1937.
2 DEFINITION
Ground Proximity Warning System (GPWS): An equipment installed in an
aeroplane for the purpose of providing automatically a timely and distinctive
warning to the flight crew when the aeroplane is in potentially hazardous
proximity to the earth's surface.
Rev. 5, Oct 2022 43 REQUIREMENTS
3.1 All turbine-engined aeroplanes of a maximum certificated take-off mass in excess
of 5 700 kg or authorized to carry more than nine passengers shall be equipped
with a ground proximity warning system which has a forward-looking terrain
avoidance function.
3.2 The operator shall implement database management procedures that ensure the
timely distribution and update of current terrain and obstacle data to the ground
proximity warning system.
3.3 All turbine-engined aeroplanes of a maximum certificated take-off mass of 5 700
kg or less and authorized to carry more than five but not more than nine
passengers should be equipped with a ground proximity warning system which
provides the warnings as para 4.1 a) and c), warning of unsafe terrain clearance
and a forward looking terrain avoidance function.
3.4 All turbine-engined aeroplanes of a maximum certificated take-off mass of 5 700
kg or less and authorized to carry more than five but not more than nine
passengers for which the individual certificate of airworthiness is first issued on or
after 1 January 2026, shall be equipped with a ground proximity warning system
which provides the warnings of 4.1 a) and c), warning of unsafe terrain clearance
and a forward looking terrain avoidance function.
3.5 All piston-engined aeroplanes of a maximum certificated take-off mass in excess
of 5 700 kg or authorized to carry more than nine passengers shall be equipped
with a ground proximity warning system which provides the warnings in para 4.1
a) and c), warning of unsafe terrain clearance and a forward-looking terrain
avoidance function.
3.6 A ground proximity warning system shall provide automatically a timely and
distinctive warning to the flight crew when the aeroplane is in potentially
hazardous proximity to the earth’s surface.
Note: The forward looking terrain avoidance warning equipment is commonly known
Enhanced Ground Proximity Warning System (EGPWS) or Ground Collision
Avoidance System (GCAS).
4 OPERATIONAL REQUIREMENTS
4.1 A ground proximity warning system shall provide, unless otherwise specified
herein, warnings under the following circumstances :
a) excessive descent rate ;
Rev. 5, Oct 2022 4b) excessive terrain closure rate ;
c) excessive altitude loss after take-off or go-around ;
i) unsafe terrain clearance while not in landing configuration gear not
locked down ;
ii) flap not in landing position ; and
e) excessive descent below the instrument glide path.
4.2 Prior to operation of the aeroplane fitted with GPWS as required by para 3, the
aeroplane flight manual shall contain appropriate procedures for-
a) the use of GPWS equipment;
b) amendment to the checklist to include GPWS;
c) flight crew action with respect to the warnings provided by GPWS
equipment;
d) de-activation for planned abnormal and emergency conditions;
e) inhibition of mode 4 warnings based on flap being in other than the
landing configuration if the system incorporates a mode 4 flap warning
inhibition control.
4.3 Deactivation of GPWS can only be in accordance with the
procedurescontained in the aeroplane flight manual.
4.4 Whenever GPWS is de-activated, an entry shall be made in the aeroplane
maintenance record that includes the date and time of the de-activation and
the deactivation properly placarded in the cockpit.
5. The operators are encouraged that in addition to the warning modes given in
para 4.1, the following modes may also be provided for the purpose of
enhanced safety of flight operations:
5.1 Forward-looking wind shear warning system - jet aeroplanesAll turbo-jet
aeroplanes of a maximum certificated take-off mass in excess of 5 700 kg or
authorized to carry more than nine passengers may be equipped with a
forward-looking wind shear warning system. A forward-looking wind shear
warning system should be capable of providing the pilot with a timely aural
and visual warning of wind shear ahead of the aircraft, and the information
required to permit the pilot to safely commence and continue a missed
approach or go-around or to execute an escape manoeuvre, if necessary.
The system should also provide an indication to the pilot when the limits
specified for the certification of automatic landing equipment are being
approached, when such equipment is in use.
5.2 Altitude call-out and excessive bank angle alert.
6. GENERAL REQUIREMENTS
6.1 The GPWS shall be of an approved type and meet the specifications given in
the FAA TSO C-92 C or any other specification acceptable to DGCA. In case
Rev. 5, Oct 2022 4of EGPWS and GCAS they should meet the specifications given in FAA
TSO-C151a or JAA JTSO C151a or any other specifications acceptable to
DGCA. The Forward looking Wind shear Warning Systems should meet the
requirements given in FAA TSO-C117a or any specifications acceptable to
DGCA.
6.2 The GPWS shall be installed in an approved manner by an approved
organisation/manufacture and shall be maintained in serviceable condition.
6.3 Engineers certifying the maintenance of GPWS should hold appropriate type
rated CAR 66 AME licence as applicable and should be adequately trained
on this equipment.
6.4 The Operations Manual shall be amended to reflect any change in the
operating procedures, where applicable.
(Arun Kumar)
Director General of Civil Aviation
Rev. 5, Oct 2022 4