02-8989. Airworthiness Directives; Univair Aircraft Corporation Models (ERCO) 415-C, (ERCO) 415-CD, (ERCO) 415-D, (ERCO) 415-E, (ERCO) 415-G, (Forney) F-1, and (Forney) F-1A Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); Reopening of the comment period.

SUMMARY:

This document proposes to revise an earlier proposed airworthiness directive (AD) that would have superseded Airworthiness Directive (AD) 86-22-09 and would have applied to all Univair Aircraft Corporation Models (ERCO) 415-C, (ERCO) 415-CD, (ERCO) 415-D, (ERCO) 415-E, (ERCO) 415-G, (Forney) F-1, and (Forney) F-1A airplanes with the gascolator connected to the side of the carburetor. The earlier NPRM would have required you to replace any aluminum fuel line nipple with a brass or steel fuel line nipple, inspect for the existence of double support tubes on the gascolator, and install these tubes if they do not exist. Since issuance of the NPRM, we have determined that we should: supersede AD 46-38-03 and incorporate the actions of that AD into the proposed AD, require a one-time inspection of the fuel line fittings, incorporate revised service information into the AD, and reduce the compliance time. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these additional actions.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before May 30, 2002.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-79-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays. You may also send comments electronically to the following address: [e-mail]. Comments sent electronically must contain “Docket No. 2000-CE-79-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII text.

You may get service information that applies to this proposed AD from Univair Aircraft Corporation, 2500 Himalaya Road, Aurora, Colorado 80011; telephone: [phone]; facsimile: [phone]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Elizabeth Bumann, Aerospace Engineer, FAA, Denver Aircraft Certification Office, 26805 East 68th Avenue, Room 214, Denver, Colorado 80249; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? The FAA invites comments on this proposed 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. We may amend this proposed rule in light of comments received.

Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of this proposed AD action and determining whether we need to take additional rulemaking action.

Are there any specific portions of this proposed AD I should pay attention to? The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of this proposed rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each contact we have with the public that concerns the substantive parts of this proposed AD.

How can I be sure FAA receives my comment? If you want FAA to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2000-CE-79-AD.” We will date stamp and mail the postcard back to you.

Discussion

What is the background of the subject matter? Reports of fuel leakage due to cracked fuel line nipples on Univair 415 series and Models F1 and F1A airplanes caused FAA to issue AD 86-22-09, Amendment 39-5457. This AD requires you to accomplish the following on Univair Models (ERCO) 415-C, (ERCO) 415-CD, (ERCO) 415-D, (ERCO) 415-E, (ERCO) 415-G, (Forney) F-1, and (Forney) F-1A airplanes:

—Inspect the fuel line nipple between the gascolator and the carburetor for cracks or misalignment; and

—Replace any suspect part.

These actions are specified in Univair Service Bulletin No. 24A, dated August 22, 1986.

The FAA has received reports of failure of the aluminum fuel line nipple, part number AN911-2D, on airplanes that were in compliance with AD 86-22-09. In one instance, a Model (ERCO) 415-C made an emergency landing because the failure led to engine fuel starvation.

AD 86-22-09 requires a one-time inspection of the part number AN911-2D fuel line nipple. Since 15 years have passed since issuance of that AD, most of the affected airplanes have had this inspection accomplished. If the fuel line nipple was not suspect at the time of inspection, then final AD compliance was obtained. In 15 years, cracks could develop in the aluminum fuel line nipple on these airplanes in compliance with AD 86-22-09.

In addition, Univair Service Bulletin No. 24A, dated August 22, 1986, also specifies replacing any aluminum fuel line nipple with a brass or steel fuel line nipple and installing double support tubes on the gascolator for those airplanes with a gascolator connected to the side of the carburetor. AD 86-22-09 required the fuel line nipple replacement only if damage was found during the one-time inspection and did not require installation of the double support tubes.

What is the potential impact if FAA took no action? This condition, if not corrected, could result in failure of the fuel line fittings or the gascolator because of the current airplane design configuration (aluminum fuel line nipples, aluminum fuel line elbows, and/or no double support tubes on the gascolator). Such failure could result in a lack of fuel to the engine with consequent loss of control of the airplane.

Has FAA taken any action to this point? We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Univair (ERCO) 415-C, (ERCO) 415-CD, (ERCO) 415-D, (ERCO) 415-E, (ERCO) 415-G, (Forney) F-1, and (Forney) F-1A airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 4, 2001 (66 FR 50578). The NPRM proposed to supersede AD 86-22-09 with a new AD that would require you to accomplish the following on airplanes with the gascolator connected to the side of the carburetor:

—Replace any aluminum fuel line nipple with a brass or steel fuel line nipple; and

—Inspect for the existence of double support tubes on the gascolator and install these tubes if they do not exist.

The proposed AD would not affect those airplanes with the gascolator mounted on the firewall.

Was the public invited to comment? The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:

Comment Issue No. 1: Several ADs Already Address the Unsafe Condition

What is the commenter's concern? One commenter states that the proposed AD is unnecessary because the unsafe condition is already addressed in other AD actions and through manufacturer service memorandums and service bulletins. In particular, the commenter states that AD 86-22-09 requires replacement of the aluminum nipple because that is specified in Mandatory Service Bulletin 24A, dated August 22, 1986. The commenter further believes that AD 86-22-09 requires installation of the double support brackets because the installation is referenced in the service information. The commenter believes that FAA is proposing this AD to point out that owners and mechanics are not complying with existing ADs and service bulletins. The commenter recommends that we withdraw the NPRM.

What is FAA's response to the concern? We do not concur. AD 86-22-09 requires a one-time inspection of the aluminum AN911-2D fuel line nipples with replacement if necessary. After inspection or replacement, this AD requires no further action and, if the fuel line nipple was not found damaged, then the replacement was not required. We have received reports of failure of the aluminum fuel nipple on airplanes that are in compliance with AD 86-22-09. The only way we can mandate the actions of a manufacturer's service bulletin is through the issuance of an AD. Therefore, we are not withdrawing this NPRM.

After carefully reviewing all incident reports concerning this subject, we have also determined that we should add to the NPRM a requirement for a one-time visual inspection of the fuel line fittings between the carburetor and gascolator for cracks and misalignment (with any necessary replacement).

Since this addition to the NPRM increases the burden over that already proposed, we are issuing this action as a supplemental NPRM and reopening the comment period to allow the public the chance to comment.

Comment Issue No. 2: Include Actions To Address the Fuel Nipple and Elbow Between the Gascolator and Carburetor

What is the commenter's concern? Two commenters suggest that FAA address in the NPRM the areas of the fuel nipple and elbow between the gascolator and carburetor. This suggestion is based on service experience of both commenters' airplanes. Although one commenter recommends no specific action, we infer that this commenter wants us to consider the elbow when ensuring that no aluminum fuel line fittings are installed between the gascolator and carburetor.

What is FAA's response to the concern? We concur that the elbow and nipple aluminum fittings located in the area between the gascolator and carburetor are susceptible to the same failure and the proposed action should address both. AD 46-38-03 currently requires a one-time replacement of the aluminum elbow fittings for certain Univair (ERCO) 415-C, (ERCO) 415--CD, and (ERCO) 415-D airplanes. We have determined that the proposed action should supersede AD 46-38-03, should retain this one-time replacement for the above-referenced airplanes, and should extend the replacement to all airplanes affected by this proposed action.

Since this addition to the NPRM increases the burden over that already proposed, we are issuing this action as a supplemental NPRM and reopening the comment period to allow the public the chance to comment.

Comment Issue No. 3: Only Require Installation of Steel Fuel Line Elbows and Nipples

What is the commenter's concern? One commenter recommends that FAA only allow the installation of steel fuel line elbows and nipples. This commenter relates an experience where a brass elbow failed because brass does not have the same destruction resilience as steel under vibration conditions.

What is FAA's response to the concern? We do not concur. Although brass is softer than steel, FAA's analysis of the service history indicates that the installation of a brass fuel line elbow or nipple provides an acceptable level of safety when support tubes are installed and the fittings are properly aligned.

The support tube installation is proposed in this action and the proper alignment of the fittings is part of the installation procedures of the proposed AD.

Comment Issue No. 4: Require a Rubber Cushion Between the Adel Clamp and the Gascolator

What is the commenter's concern? One commenter communicates a problem with the rigid bracing at the far end of the gascolator. This commenter states that the only attach point for the entire assembly to the engine is the two studs that attach the spider manifold to the engine. This attachment is a shock mounting to the engine, which absorbs some vibration. The commenter states that, with this configuration, the gascolator at the end of the line is bound to have vibration, which is stopped by the rigid bracing. The commenter also states that the weak part of the gascolator system picks up this vibration load. The commenter recommends that FAA propose to require the installation of a rubber cushion between the adel clamp and the gascolator to absorb this vibration load.

What is FAA's response to the concern? We do not concur that a rubber cushion should be installed between the adel clamp and the gascolator on the affected airplanes. Our review of the service history of these airplanes indicates that the current configuration is an airworthy design.

We are not changing the proposed rule as a result of this comment.

Comment Issue No. 5: Reduce the Compliance Time to “Prior to Further Flight”

What is the commenter's concern? One commenter wants FAA to revise the compliance time from 50 hours time-in-service (TIS) to prior to further flight. This commenter states that the affected airplanes are not airworthy without gascolator support tubes because the only support is aluminum fuel line fittings. The commenter further communicates the following:

—If a failure is a complete breakage of one of the aluminum fittings, the fuel will drain into the engine compartment from the fuselage tank;

—The fuel pump will continue to pump fuel from the wing tanks into the fuselage tank, which will continue to drain into the engine compartment until the engine quits;

—The engine will quit within seconds and give the pilot very little time to find a safe landing place;

—Up to six gallons of fuel could drain into the engine compartment if the pilot fails to remember to shut off the main fuel valve; and

—If an aluminum fuel line fitting cracks and leaks fuel, then this fuel or vapors could come too close to the hot exhausts and create a fire.

What is FAA's response to the concern? The FAA partially concurs. Things we consider in determining the type of action to take include the nature of the problem, the service history, the way the airplanes are used, and the logistics of having the action accomplished on the entire airplane fleet. Based on this, we have determined that we do not have justification for a “prior to further flight” compliance time. However, because a significant percentage of the affected airplanes are used for personal recreation and accumulate an average of 35 to 40 hours TIS per year, we are proposing a change in the compliance time from 50 hours TIS to 25 hours TIS.

Since this change to the NPRM increases the burden over that already proposed, we are issuing this action as a supplemental NPRM and reopening the comment period to allow the public the chance to comment.

Comment Issue No. 6: Reference a Later Revision of the Service Information

What is the commenter's concern? Since issuance of the NPRM, Univair has revised the service information (Univair Service Bulletin No. 24B, dated January 29, 2002) for this action. This service bulletin revision includes detailed instructions for installing and adjusting the gascolator support braces, includes proper brace numbers for all affected airplane models, and specifies the option of replacing the existing glass bowl gascolator with an all-metal gascolator. Univair requests that FAA incorporate this service bulletin into the proposed AD.

What is FAA's response to the concern? We will incorporate this service bulletin into the proposed AD. However, we will not reference the all-metal gascolator optional installation since it is not the subject matter of this proposed AD.

Comment Issue No. 7: Make the AD Apply to All Aluminum Fuel Line Nipples

What is the commenter's concern? One commenter requests that we remove reference to the part number of the aluminum fuel line nipple. The commenter states that any fuel line nipple made from aluminum should be replaced with an AN911-2 fitting made of steel or brass. The commenter states that removing this reference would ensure that no aluminum fittings are installed between the gascolator and the carburetor

What is FAA's response to the concern? We concur and will change the proposed AD accordingly.

The FAA's Determination

What has FAA decided? After examining the circumstances and reviewing all available information related to the incidents described above, we have determined that the NPRM should be expanded to include:

—A one-time inspection of the fuel line fittings;

—Replacement of the aluminum elbow fittings;

—The incorporation of Univair Service Bulletin No. 24B, dated January 29, 2002; and

—A change in the compliance time from 50 hours TIS to 25 hours TIS.

The Supplemental NPRM

How will the changes to the NPRM impact the public? Proposing that the NPRM incorporate these additions and changes presents actions that go beyond the scope of what was already proposed. Therefore, we are issuing a supplemental NPRM and reopening the comment period to allow the public additional time to comment on the proposed AD.

What are the provisions of the supplemental NPRM? The proposed AD would supersede AD 86-22-09 and AD 46-38-03 and would require you to:

—Replace any aluminum fuel line nipple with a brass or steel fuel line nipple;

—Replace any aluminum elbow fitting with a brass or steel elbow fitting;

—Inspect for the existence of double support tubes on the gascolator, and install these tubes if they do not exist; and

—Inspect the fuel line fittings between the carburetor and gascolator for cracks or misalignment and replace as necessary.

Cost Impact

How many airplanes would this proposed AD impact? We estimate that this proposed AD would affect 2,500 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the proposed inspection, replacements, and installation:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
2 workhours at $60 per hour = $120.	$70	$190 per airplane	$475,000

Regulatory Impact

Would this proposed AD impact various entities? The regulations proposed herein would 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, it is determined that this proposed rule would not have federalism implications under Executive Order 13132.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed action (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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action has been placed in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

§ 39.13

[Amended]

2. FAA amends § 39.13 by removing Airworthiness Directive (AD) 46-38-03 and AD 86-22-09, Amendment 39-5457, and by adding a new AD to read as follows:

UNIVAIR Aircraft Corporation: Docket No. 2000-CE-79-AD; Supersedes AD 46-38-03 and AD 86-22-09, Amendment 39-5457.

(a) What airplanes are affected by this AD? This AD affects all serial numbers of Models (ERCO) 415-C, (ERCO) 415-CD, (ERCO) 415-D, (ERCO) 415-E, (ERCO) 415-G, (Forney) F-1, and (Forney) F-1A airplanes that:

(1) are certificated in any category; and

(2) have the gascolator connected to the side of the carburetor. This AD does not affect those airplanes with the gascolator mounted on the firewall.

(b) Who must comply with this AD? Anyone who wishes to operate any of the airplanes identified in paragraph (a) of this AD must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to prevent failure of the fuel line fittings or the gascolator because of the current airplane design configuration (aluminum fuel line nipples, aluminum fuel line elbows, and/or no double support tubes on the gascolator). Such failure could result in a lack of fuel to the engine with consequent loss of control of the airplane.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

Actions	Compliance	Procedures
(1) Visually inspect the fuel line nipple and elbow located between the carburetor and gascolator for cracks or misalignment, and replace as necessary.	Inspect within the next 25 hours time-in-service (TIS) after the effective date of this AD and replace prior to further flight after the inspection. You must inspect even if you have inspected previously	In accordance with Univair Service Bulletin No. 24B, dated January 29, 2002.
(2) Replace any aluminum fuel line nipple with one made of brass or steel.	Within the next 25 TIS after the effective date of this AD, unless already accomplished (compliance with AD 86-22-09 and/or Univair Service Bulletin No. 24A, dated August 22, 1986)	In accordance with Univair Service Bulletin No. 24B, dated January 29, 2002.
(3) Replace any aluminum fuel elbow fitting with one made of brass or steel. Manufacturer replacement parts numbers are referenced in this service information.	Within the next 25 hours TIS after the effective date of this AD, unless already accomplished (compliance with AD 46-38-03)	In accordance with Univair Service Bulletin No. 24B, dated January 29, 2002.
(4) Inspect for the existence of double support tubes on the gascolator and install these tubes if they do not exist, as follows: (i) For all affected airplanes except for (Forney) F-1 and (Forney) F-1A airplanes, install part numbers 48076 and 48096 (or FAA-approved equivalent part numbers) double support tubes; and (ii) For all affected (Forney) F-1 and (Forney) F-1A airplanes, install part numbers 48098 and 48099 (or FAA-approved equivalent part numbers) double support tubes.	Inspect within the next 25 hours TIS after the effective date of this AD and install the double support tubes prior to further flight after the inspection, unless already accomplished (compliance with Univair Service Bulletin No. 24A, dated August 22, 1986)	In accordance with Univair Service Bulletin No. 24B, dated January 29, 2002.
(5) Do not install, on any affected airplane, an aluminum fuel line nipple or aluminum elbow.	As of the effective date of this AD	Not Applicable.
(6) Do not install a gascolator on the side of the carburetor on any affected airplane, unless the double support tubes specified in paragraph (d)(4)(i) or (d)(4)(ii) of this AD are installed.	As of the effective date of this AD	Not Applicable.

(e) Can I comply with this AD in any other way?

(1) You may use an alternative method of compliance or adjust the compliance time if:

(i) Your alternative method of compliance provides an equivalent level of safety; and

(ii) The Manager, Denver Aircraft Certification Office, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager.

(2) Alternative methods of compliance approved in accordance with AD 46-38-03 and/or AD 86-22-09, which are superseded by this AD, are not approved as alternative methods of compliance with this AD.

Note:

This AD applies to each airplane identified in paragraph (a) of this AD, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Elizabeth Bumann, Aerospace Engineer, FAA, Denver Aircraft Certification Office, 26805 East 68th Avenue, Room 214, Denver, Colorado 80249; telephone: [phone]; facsimile: [phone].

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) How do I get copies of the documents referenced in this AD? You may get copies of the documents referenced in this AD from Univair Aircraft Corporation, 2500 Himalaya Road, Aurora, Colorado 80011; telephone: [phone]; facsimile: [phone]. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

(i) Does this AD action affect any existing AD actions? This amendment supersedes AD 46-38-03 and AD 86-22-09, Amendment 39-5457.

Issued in Kansas City, Missouri, on April 5, 2002.

Dorenda D. Baker,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.