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Regulatory Brief -- Changes in FAA certification standards could lead to new affordable technologies and improved safetyRegulatory Brief -- Changes in FAA certification standards could lead to new affordable technologies and improved safety

Regulatory Brief

Changes in FAA certification standards could lead to new affordable technologies and improved safety

The issue:

After years of effort the Federal Aviation Administration has issued a new advisory circular outlining the AOPA-advocated concept of multi-tiered airworthiness certification standards for avionics and other equipment. Advisory Circular 23.1309-1C explains to manufacturers of general aviation avionics and other equipment how to demonstrate compliance with existing certification regulations under the multi-tiered approach.

The importance to our members:

The aviation industry as a whole is on the threshold of a revolutionary change in the manner in which communication, navigation, and surveillance of aircraft operations is conducted. This complete overhaul of the National Airspace System (NAS) is intended to take advantage of new technology and will likely result in the long-term replacement of nearly all avionics equipment in the existing fleet as well as new production aircraft. If general aviation is to operate within a revised NAS system, it is imperative that new technologies be made available and affordable for general aviation aircraft.

Significant provisions:

  • Most general aviation avionics and equipment today is deemed to be critical to the safety of flight and must be certificated to a 10 -9 reliability level (one in a billion chance of failure).
  • The new advisory circular institutes a multi-tiered approach to certification standards.
  • The first step is to consider what failure conditions could exist for a given piece of equipment.
  • The second step is to consider what effect each of the failure conditions would have on the aircraft and crew.
  • Equipment such as a communication radio whose total failure would result in minimal danger to the aircraft and its occupants might be certificated to a 10 -3 level (on in a thousand).
  • More critical equipment such as attitude information display for IFR flight might be considered in several ways;
  1. A complete failure that can be readily identified by the pilot might be considered to have a major impact on the continued safe flight because it forces the use of partial panel procedures and dramatically increases pilot workload. This might require a certification level of 10 -4;
  2. A failure condition that gives misleading attitude information without ready means of identification by the pilot might be considered catastrophic under IMC and require a certification level of 10 -7.
  3. In-flight fire is almost always considered to be catastrophic.
  • The changes could significantly reduce certification costs allowing more complex technologies to filter into the general aviation marketplace.
  • There would not be reduction in safety because the certification standard more closely reflects actual reliability rates experienced in the field today.
  • Safety could actually be significantly enhanced over the long term by making equipment available to general aviation that could better address the major causes of GA accidents such as weather avoidance and ground proximity warning technologies.

AOPA position:

AOPA has strongly supported efforts to develop the concept of multi-tiered certification and institutionalize the new processes within the FAA. We believe that if future new equipment provides enough operational benefit at a reasonable cost, pilots will buy it. Those operational benefit derived from new technologies such as digital communications, data link, satellite based navigation, etc. could reduce pilot workload and provide critical information in the cockpit including real-time weather data and ground proximity warnings.


On September 8, 1998, the FAA published the long-awaited draft Advisory Circular 23.1309-1C for public comment. AOPA submitted comments in support of the draft AC on November 4, 1998. On March 12, 1999, the FAA published the final version of the AC incorporating some of AOPA�s comments in the text of the final AC. AOPA will continue to work on ways to ensure that new safety enhancing technologies can become available to general aviation in the most affordable manner possible.

Related documents:

AOPA comments to draft Advisory Circular 23.1309-1C, November 4, 1998.

Final AC 23.1309-1C, Equipment, Systems, and Installation in Part 23 Airplanes, March 12, 1999 (requires Adobe Reader).

AOPA Press Release 99-1-097