Discussion
The Eclipse Model EA500 has experienced three instances of loss of primary airspeed indication due to freezing condensation within the pitot system. The loss of air pressure in the pitot system could cause the stall warning to become unreliable and the stick pusher, overspeed warning, and autopilot to not function. The concern is heightened by the aerodynamic characteristics of the Eclipse Model EA500 airplane, which relies on the stall warning and the stick pusher to alert the pilot prior to the loss of aircraft control. The standby airspeed is reliable and not affected by this failure mode. A temporary AFM revision prohibits operation in instrument meteorological conditions (IMC), requires two pilots, and limits the airspeed and altitude envelope if the event occurs in flight. The AFM limitations and FAA operational rules allow Model EA500 flight crews to file an instrument flight rule (IFR) flight plan even though the airplane is not approved for flight in IMC.
ATC has expressed that filing IFR flight plans and being unable to operate in IMC creates an undue workload burden on the controller workforce when the pilots have to refuse any instructions that take them into IMC. This burden (combined with the potential for the stall warning to become unreliable and the stick pusher, overspeed warning, and autopilot to not function) compromises the continued operational safety of the Eclipse Model EA500 airplanes.
There is precedent where the FAA used AD action to correct unsafe conditions within the National Airspace System (NAS). An example of this occurred in 1998 when workload and communication problems with ATC were addressed as an unsafe condition through AD action on ATC transponders and the Traffic Alert and Collision Avoidance System (TCAS). For example, the FAA issued AD 98-14-03, Amendment 39-10637, when misleading or inaccurate encoding altimeter information caused ATC transponders to interact negatively with ground-based ATC radar sites and nearby TCAS-equipped aircraft. The inability of the ground-based ATC radar sites to coordinate this information and communicate with nearby TCAS-equipped aircraft jeopardized the NAS and created an unsafe condition.
FAA's Determination and Requirements of This AD
An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because of:
ATC's ability to maintain traffic separation and maintain a safe NAS is compromised due to the undue workload burden on the controller workforce when the pilots have to refuse any instructions that take them into IMC; and
The potential for the stall warning to become unreliable and the stick pusher, overspeed warning, and autopilot to not function due to loss of air pressure in the pitot system compromises the continued operational safety of the Eclipse Model EA500 airplanes.
Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days.
This AD requires you to incorporate information into the Limitations section of the AFM that will require operation only in day VFR, allow only a VFR flight plan, and maintain operation with two pilots. The day VFR limitation will prohibit flight at night because it is more difficult to avoid inadvertent flight into IMC at night.
This is considered interim action. Eclipse is working on a modification to the pitot system. We will consider taking additional rulemaking action to supersede this AD and terminate the above limitations when Eclipse completes the design modification to the pitot system and the FAA approves it as addressing the unsafe condition.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and an opportunity for public comment. We invite you to send any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number "FAA-2007- 28462; Directorate Identifier 2007-CE-056-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive concerning 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
We determined that 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.
We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
Examining the AD Docket
You may examine the AD docket that contains the AD, the regulatory evaluation, any comments received, and other information on the Internet at http://dms.dot.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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 airworthiness directive (AD):