Discussion
What Events Have Caused this AD?
The FAA has received reports from Raytheon that indicate during maintenance on one of the affected airplanes, it was discovered that the airflow paths of the anti-ice system between the outer skin and inner leading edge skin of the wing were obstructed. The obstruction is caused by sealant that is applied to the wing leading edge during manufacture. This condition has been found on six other affected airplanes. Obstruction of the airflow paths prevents the hot air from the anti-ice system from properly distributing heat on the wing leading edge. Heat is necessary on the wing leading edge to prevent leading edge ice formation or runback ice.
What Are the Consequences If the Condition Is Not Corrected?
This condition, if not corrected, could result in ice formation on the wing leading edges and the upper and lower wing surfaces during flight in icing conditions. Ice formation on the wings could cause symmetric or asymmetric loss of lift, degradation of handling qualities, and increased drag of the airplane.
Is There a Modification I Can Incorporate Instead of Adding the Temporary Changes to the Airplane Flight Manual (AFM)?
The FAA has determined that long-term continued operational safety would be better assured by design changes that remove the source of the problem rather than by temporary changes to the AFM or other special procedures. With this in mind, we will continue to work with Raytheon in collecting information to determine whether a future design change may be necessary.
The FAA's Determination and an Explanation of the Provisions of This AD-What Has FAA Decided?
The FAA has reviewed all available information and determined that:
-The unsafe condition referenced in this document exists or could develop on other Raytheon Model 390 airplanes of the same type design; and
-AD action should be taken in order to correct this unsafe condition.What Does This AD Require?
This AD requires you to insert a temporary change into the FAA-approved AFM that adds a limitation for prohibiting flight into icing conditions and adds procedures for when an icing condition occurs.
In preparation of this rule, we contacted type clubs and aircraft operators to obtain technical information and information on operational and economic impacts. We did not receive any information through these contacts. If received, we would have included, in the rulemaking docket, a discussion of any information that may have influenced this action.
Will I Have the Opportunity To Comment Prior to the Issuance of the Rule?
Because the unsafe condition described in this document could result in ice formation on the wings, we find that notice and opportunity for public prior comment are impracticable. Therefore, good cause exists for making this amendment effective in less than 30 days.
Comments Invited
How Do I Comment on This AD?Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, FAA invites your comments on the rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date specified above. We may amend this rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether we need to take additional rulemaking action.
Are There Any Specific Portions of the AD I Should Pay Attention To?
We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closingdate of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of this AD.
How Can I Be Sure FAA Receives My Comment?
If you want us to acknowledge the receipt of your mailed comments, you must include a self-addressed, stamped postcard. On the postcard, write "Comments to Docket No. 2002-CE-19-AD." We will date stamp and mail the postcard back to you.
Compliance Time of This AD
What Is the Compliance Time of This AD?
The compliance time of this AD is "within the next 15 calendar days after the effective date of this AD."
Why Is the Compliance Time Presented in Calendar Time Instead of Hours Time-in-Service (TIS)?
Although ice formation on the wings is only unsafe during flight, this unsafe condition is not a result of the number of times the airplane is operated. The chance of this situation occurring is the same for an airplane with 10 hours time-in-service (TIS) as it would be for an airplane with 500 hours TIS. For this reason, the FAA has determined that a compliance based on calendar time should be utilized in this AD in order to assure that the unsafe condition is addressed on all airplanes in a reasonable time period.
Regulatory Impact
Does This AD Impact Various Entities?
These regulations 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. Therefore, FAA has determined that this final rule does not have federalism implications under Executive Order 13132.
Does This AD Involve a Significant Rule or Regulatory Action?
We have determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a significant regulatory action under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket (otherwise, an evaluation is not required). A copy of it, if filed, may be obtained from the Rules Docket.
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 Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. FAA amends Sec. 39.13 by adding a new airworthiness directive (AD) to read as follows: