Airworthiness Directives: Piper Aircraft Corporation PA31, PA31P, and PA31T Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-CE-57-AD; Amendment 39-8810; AD 93-24-02 R1]

Airworthiness Directives: Piper Aircraft Corporation PA31, PA31P,

and PA31T Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment revises Airworthiness Directive (AD) 93-24-02,

which currently requires inspecting the elevator control tube assembly

area for damage (cracks, separation, corrosion, wear, elongated holes,

etc.) on Piper Aircraft Corporation (Piper) PA31, PA31P, and PA31T

series airplanes, and replacing any damaged parts. An incident where

one of the affected airplanes experienced complete loss of elevator

control while in flight prompted that AD. Since issuance of that

action, the Federal Aviation Administration (FAA) has received reports

that the figure contained in the AD specifies an incorrect installation

of the elevator control tube assembly. This action maintains the

requirements of the previous AD, and corrects the figure to reflect the

correct installation. The actions specified by this AD are intended to

prevent elevator control problems caused by a damaged elevator control

tube assembly, which could result in loss of control of the airplane.

DATES: Effective February 15, 1994.

Comments for inclusion in the Rules Docket must be received on or

before March 31, 1994.

ADDRESSES: Submit comments in triplicate to the FAA, Central Region,

Office of the Assistant Chief Counsel, Attention: Rules Docket No. 93-

CE-57-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Information that relates to this AD may be examined at the FAA,

Central Region, Office of the Assistant Chief Counsel, Attention: Rules

Docket 93-CE-57-AD, room 1558, 601 E. 12th Street, Kansas City,

Missouri 64106.

FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer,

FAA, Atlanta Aircraft Certification Office, 1669 Phoenix Parkway, suite

210C, Atlanta, Georgia 30349; telephone (404) 991-2910; facsimile (404)

991-3606.

SUPPLEMENTARY INFORMATION: AD 93-24-02, Amendment 39-8751 (58 FR 63524,

December 2, 1993), currently requires inspecting the elevator control

tube assembly area for damage (cracks, separation, corrosion, wear,

etc.) on Piper PA31, PA31P, and PA31T series airplanes, and replacing

any damaged parts.

A report of an incident where a Piper PA31T series airplane

experienced a loss of elevator control while in flight prompted AD 93-

24-02. The pilot landed the airplane safely using the elevator trim

control. Investigation by the National Transportation Safety Board

(NTSB) and the FAA disclosed that the aft control rod end bearing, part

number (P/N) 49261-02, had separated into two pieces. This aft control

rod end bearing connects the elevator control tube to the elevator

horn. The elevator control was subsequently mechanically disconnected

from the pilot's control yoke and the elevator downspring. Further

investigation revealed a fatigue crack at the thread root, which

extended through the rod end cross section.

This incident prompted this operator to conduct an inspection of

the elevator control tube assembly area on all of the Piper PA31,

PA31P, and PA31T series airplanes in this particular operator's fleet.

The results were summarized in a Mechanical Reliability Report (MRR),

which was submitted to the FAA. This MRR specifies problems in the

elevator control tube assembly area on 21 of the 23 inspected

airplanes. The following briefly describes some of the discrepancies:

13 airplanes had incorrect push rod connecting bolts

installed in the forward or aft positions (or both);

12 airplanes had push rod connecting bolts with wear or

pitting corrosion (or both) in the shank area;

13 airplanes had excessive play in the aft rod end

bearings;

7 airplanes had aft rod ends with moderate to severe wear

or corrosion (or both) on the bearing ball; and

3 airplanes had binding in the rod ends, one of which was

completely frozen.

Since issuance of AD 93-24-02, the FAA has received several reports

that the figure contained in the AD specifies an incorrect installation

of the elevator control tube assembly area. In particular, the figure

depicts installation of the AN174-11A and AN174-12A bolts with a

castellated nut and cotter pin. This installation is actually

accomplished utilizing a MS20365-428C nut instead of a castellated nut

and cotter pin.

After examining the circumstances and reviewing all available

information related to the incidents described above, the FAA has

determined that AD 93-24-02 should be revised in order to prevent

elevator control problems caused by a damaged elevator control tube

assembly.

Since an unsafe condition has been identified that is likely to

exist or develop in other Piper PA31, PA31P, and PA31T series airplanes

of the same type design, this AD revises AD 93-24-02 by (1) maintaining

the requirement of inspecting the elevator control tube assembly area

for damage, and replacing any damaged part; and (2) correcting the

Figure contained in the AD to include the correct installation of the

AN174-11A and AN174-12A bolts.

Since a situation exists that requires the immediate adoption of

this regulation, it is found that notice and opportunity for public

prior comment hereon are impracticable, and that good cause exists for

making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves

requirements affecting immediate flight safety and, thus, was not

preceded by notice and opportunity to comment, comments are invited on

this rule. Interested persons are invited to comment on this rule by

submitting such written data, views, or arguments as they may desire.

Communications should identify the Rules Docket number and be submitted

in triplicate to the address specified above. All communications

received on or before the closing date for comments will be considered,

and this rule may be amended in light of the comments received. Factual

information that supports the commenter's ideas and suggestions is

extremely helpful in evaluating the effectiveness of the AD action and

determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the rule that might

suggest a need to modify the rule. All comments submitted will be

available, both before and after the closing date for comments, in the

Rules Docket for examination by interested persons. A report that

summarizes each FAA-public contact concerned with the substance of this

AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket No. 93-CE-57-AD.'' The postcard will be date stamped and

returned to the commenter.

The regulations adopted herein will not have substantial direct

effects 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, in

accordance with Executive Order 12612, it is determined that this final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency

regulation and 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, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends 14 CFR part

39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [AMENDED]

2. Section 39.13, is amended by removing Amendment 39-8751 (58 FR

63524, December 2, 1993), and adding a new AD to read as follows:

93-24-02 R1 Piper Aircraft Corporation: Amendment 39-8810; Docket

No. 93-CE-57-AD.

Applicability: PA31, PA31P, and PA31T series airplanes (all

models and serial numbers), certificated in any category.

Compliance: Required within the next 30 hours time-in-service

after the effective date of this AD, unless already accomplished.

To prevent elevator control problems, which could lead to loss

of control of the airplane, accomplish the following:

(a) Ensure that the elevator control tube assembly area is not

damaged by accomplishing the following inspections and procedures:

(1) Gain access to the elevator controls in the tail by removing

the bottom half of the tailcone and the fuselage side panels.

(2) Remove the long pushrod that connects the bellcrank and the

elevator horn.

(3) Secure the aft end of the bungee link to the elevator horn

with safety wire for removal and installation of the bungee attach

bolt.

(4) Inspect, using FAA-approved magnetic procedures, the rod end

shank and threads for cracks. If found cracked, prior to further

flight, replace the rod end with part number (P/N) 49261-02 or P/N

452-658.

(5) Visually inspect the bearing in the rod end for wear and

free movement. If wear is found or the bearing will not move, prior

to further flight, replace the rod end with P/N 49261-02 or P/N 452-

658.

(6) Inspect, using a 10X magnifying glass, the forward attach

holes in the pushrod for cracks, corrosion, or elongation. If

cracks, corrosion, or elongation is found, prior to further flight,

replace the pushrod with P/N 40847-00, 40847-04, or 40847-07, as

applicable.

(7) Visually inspect the forward and aft attach area to ensure

that both a forward bolt, P/N 402 311 (AN 174-12A), and an aft bolt,

P/N 402 317 (AN 174-11A), are installed. If either one of these

bolts is not installed, prior to further flight, install the

applicable bolt or replace the existing bolt with one of the

applicable part number.

(8) Remove the safety wire, reinstall the pushrod, check to

ensure that the elevator rigging is correct, and reinstall the

bottom half of the tailcone and the fuselage side panels.

Note 1: Figure 1 of this AD illustrates the elevator assembly

and the specific areas that are to be inspected.

TR01FE94.014

(b) Special flight permits may be issued in accordance with FAR

21.197 and 21.199 to operate the airplane to a location where the

requirements of this AD can be accomplished.

(c) An alternative method of compliance or adjustment of the

compliance time that provides an equivalent level of safety may be

approved by the Manager, Atlanta Aircraft Certification Office

(ACO), 1669 Phoenix Parkway, suite 210C, Atlanta, Georgia 30349. The

request shall be forwarded through an appropriate FAA Maintenance

Inspector, who may add comments and then send it to the Manager,

Atlanta ACO.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Atlanta ACO.

(d) Information related to this AD may be examined at the FAA,

Central Region, Office of the Assistant Chief Counsel, Room 1558,

601 E. 12th Street, Kansas City, Missouri 64106.

(e) This amendment (39-8810) revises AD 93-24-02, Amendment 39-

8751.

(f) This amendment (39-8810) becomes effective on February 15,

1994.

Issued in Kansas City, Missouri, on January 24, 1994.

Bobby W. Sexton,

Acting Manager, Small Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-2091 Filed 1-31-94; 8:45 am]

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