Aircraft Certification Policy Letter (ACPL)
Aircraft Certification Policy Letter (ACPL)
Subject: Satellite Communications (SATCOM) Equipment and Installation Approval
The purpose of this Aircraft Certification Policy Letter (ACPL) is to provide Aircraft Certification personnel, Including delegates, with procedural guidelines for the approval of Satellite Communications (SATCOM) installations.
2.0 Reference Documents
- AC 25-10 "Guidance for Installations of Miscellaneous Non Required Electrical Equipment";
- AC 25-16 "Electrical Fault & Fire prevention & Detection"; and
- RTCA -DO-160 document "Environmental Conditions and Test Procedures for Airborne Equipment", to the revision level applicable to the aircraft.
During the Transport Canada Avionics Workshop held in April 1997, it was decided to permit the installation of SATCOM equipment on aircraft, as "non-required, non-essential avionics equipment" for use by passengers as a voice communication system. Notwithstanding the above, concerns have been raised regarding the certification of these installations and the ability of some of these systems, such as land mobile satellite systems (MSAT), to meet the basic environmental conditions and compliance with test procedures required for the certification of airborne equipment.
In addition to the normal requirements pertaining to the installation of navigation/communication systems, the installation of a SATCOM system on an aircraft is subject to the following requirements:
- The equipment shall be installed in accordance with the manufacturer's installation instructions.
- Equipment which is capable of radiating radio frequency (RF) energy, shall display warning labels indicating the health hazards potentially resulting from such equipment.
- The equipment shall display a label clearly indicating that the equipment is not intended for use with the Air Traffic Control system.
- The installed equipment shall be isolated from the aircraft electrical system, in order to preclude any hazard to the aircraft in the event of system failure during any phase of the aircraft operation.
- Where an installation does not meet the applicable Equipment Performance Standards as specified in the RTCA DO-160 section 1 document, the equipment should then be housed in an enclosure capable to either contain an internal fire, or sufficiently airtight to preclude the sustained combustion.
- The installed equipment must be capable to withstand the shocks that may occur during normal aircraft operations. This requirement must be demonstrated by tests or analyses.
- Sufficient tests must be performed to demonstrate that the equipment will not interfere with the operation of any of the aircraft's systems, including navigation/ communication systems. These tests shall be completed for each first time installation on an aircraft type in order to ensure compatibility with the navigation/communication equipment installed thereon.
- Interconnecting harnesses supplied with ground use equipment must provide a level of protection to fire and toxic smoke hazards equivalent to that required for wiring usually used in an aircraft. The level of required protection should cater for both the aircraft temperature range parameters and material insulation requirements.
- The associated antenna installation, including the attachments points should be evaluated in terms of fatigue, damage tolerance, corrosion, proper grounding and aerodynamic loads. The evaluation report should outline the resultant forces and the flutter and vibration effects on the airframe for the entire aircraft flight envelope.
(a) The ACs outlined under section 2.0, items 1) and 2) should be used as reference materials.
(b) It is recommended that the installer obtain assurance from the Satellite operator (provider) that problems, such as
Doppler effect at ground speeds in excess of 200 knots will not occur as experienced with the MSAT systems. Certain manufacturers have designed their systems to compensate for Doppler effect and possible malfunction of the satellite network.
5.0 Power Source
Where the SATCOM installation does not include a self contained power source, it is recommended that the system be powered from a "non-essential bus or equivalent" of the aircraft electrical system as to permit the crew to shed the SATCOM system without loosing any essential equipment. It should be demonstrated by an electrical load analysis that the aircraft electrical system is still capable to supply the required power, and to remain within the safety margins defined during the aircraft type certification.
This ACPL will be cancelled upon the publication of a pertinent AMA on this subject.
Original signed by:
K. J. Mansfield
Director, Aircraft Certification
- Date modified: