Discussion
We were notified of two software anomalies discovered in the Honeywell Primus EPIC and Primus APEX flight management systems (FMS): The first anomaly can occur when the destination runway is changed without an arrival or approach entered and the runway is the TO waypoint, which causes the destination runway to become the departure runway; the second anomaly can occur when crossing the 180 degree meridian, which causes the FMS longitude position calculation to move by approximately 180 degrees. These software anomalies can cause the FMS to generate misleading navigational guidance to the pilots and to the autopilot system of various airplanes having this same system software. These conditions, if not corrected, could result in an airplane departing from its scheduled flight path, which could result in possible collision with other aircraft or terrain.
Relevant Service Information
We reviewed the Honeywell service information letters (SILs) specified in the following table. The SILs describe the procedures necessary to recover from or to work around the identified software anomalies in the FMS described above.
Table--Honeywell Service Information Letters
Honeywell Service Information Letter
Revision
Model
Dated
D201002000007
Original
PC-12/47E airplanes
February 16, 2010
D201002000051
1
ERJ 170 and ERJ 190 airplanes
March 26, 2010
D201002000052
Original
ERJ 170 and ERJ 190 airplanes
March 3, 2010
FAA's Determination and Requirements of This AD
We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs. This AD requires accomplishing the actions specified in the service information described previously, except as discussed under "Difference Between the AD and the Service Information.''
Difference Between the AD and the Service Information
The SILs identified in the previous table do not specify revising the AFMs of the affected airplanes to include the information in the General Information section of the SIL; however, this AD requires revising the applicable AFM to
include that information in order to ensure that the flightcrew has the necessary procedures to recover from or work around the identified anomalies during flight.
Interim Action
We consider this AD interim action. The FMS manufacturer is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, we might consider additional rulemaking.
FAA's Justification and Determination of the Effective Date
Certain Honeywell FMS software anomalies, in certain situations, can cause the FMS to generate misleading navigational guidance to the pilots and to the autopilot system of various airplanes having this same system. This misleading navigational guidance to the pilots and to the autopilot system causes the airplane to depart from its scheduled flight path, which could result in possible collision with other aircraft or terrain. We have determined that it is imperative that we notify flightcrews of these anomalies and provide them with procedures to recover from or work around these anomalies during flight. Because of our requirement to promote safe flight of civil aircraft and thus the critical need to assure proper navigational guidance from Honeywell FMS, coupled with the short compliance time involved with this action, this AD must be issued immediately.
Because an unsafe condition exists that requires the immediate adoption of this AD, we find that notice and opportunity for prior public comment hereon are impracticable and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2010-0385; Directorate Identifier 2010-NM-068-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs,'' describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
Regulatory Findings
This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a "significant regulatory action'' under Executive Order 12866,
(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and
(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec.39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new AD: