Federal Register / Vol. 61, No. 19 / Monday, January 29, 1996 / Rules and Regulations 2703

address the unsafe condition described in

this AD. Such a request should include an

assessment of the effect of the changed

configuration on the unsafe condition

addressed by this AD. In no case does the

presence of any modification, alteration, or

repair remove any engine from the

applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.

To prevent detonation due to low octane,

which can result in severe engine damage

and subsequent failure, accomplish the

following:

(a) For engines that are certified to operate

on only 91 or higher octane aviation gasoline

(avgas) within the next 2 hours time in

service (TIS) after the effective date of this

airworthiness directive (AD) perform an

engine teardown and analytical inspection,

and replace with serviceable parts as

necessary in accordance with the applicable

overhaul manuals.

(b) For engines that are certified to operate

on 80 octane avgas, within the next 2 hours

TIS after the effective date of this AD conduct

a differential compression test on all

cylinders in accordance with the applicable

maintenance manuals, and examine the oil

filter by cutting the oil filter apart and

spreading the filter paper out to look for

metal particles. If metal particles are present,

or if one or more cylinders shows

unacceptable compression as specified in the

applicable maintenance manuals, perform an

engine teardown and analytical inspection,

and replace with serviceable parts as

necessary in accordance with the applicable

overhaul manuals.

Note: Additional guidance for conducting

differential compression tests is contained in

paragraph 692 of Advisory Circular (AC) No.

43.13–1A, dated 1988.

(c) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Engine and

Propeller Standards Staff. The request should

be forwarded through an appropriate FAA

Maintenance Inspector, who may add

comments and then send it to the Manager,

Engine and Propeller Standards Staff.

Note: Information concerning the existence

of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine and

Propeller Standards Staff.

(d) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the aircraft to

a location where the requirements of this AD

can be accomplished.

(e) This amendment becomes effective

February 13, 1996, to all persons except those

persons to whom it was made immediately

effective by priority letter AD 94–11–10,

issued June 23, 1994, which contained the

requirements of this amendment.

Issued in Burlington, Massachusetts, on

January 11, 1996.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 96–1411 Filed 1–26–96; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 95–ANE–70; Amendment 39–

9489, AD 96–02–04]

Airworthiness Directives; Franklin

Model 6A4–150–B3 and 6A4–165–B3

Reciprocating Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to Franklin Model 6A4–150–

B3 and 6A4–165–B3 reciprocating

engines, installed on the following U.S.

registered aircraft: N6209M, N74231,

and N752C. This action supersedes

priority letter AD 94–14–11 that

currently requires engines certified to

operate on 91 octane or higher avgas to

undergo a teardown and analytical

inspection for detonation damage, and

engines certified to operate on 80 octane

avgas to undergo inspection for

evidence of possible internal engine

damage. This action revises incorrect

engine model numbers listed in the

priority letter AD. This amendment is

prompted by updated information that

has identified the correct engine model

numbers. The actions specified by this

AD are intended to prevent detonation

due to low octane, which can result in

severe engine damage and subsequent

failure.

DATES: Effective February 13, 1996.

Comments for inclusion in the Rules

Docket must be received on or before

March 29, 1996.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No.

95–ANE–70, 12 New England Executive

Park, Burlington, MA 01803–5299.

FOR FURTHER INFORMATION CONTACT:

Locke Easton, Aerospace Engineer,

Engine and Propeller Standards Staff,

FAA, Engine and Propeller Directorate,

12 New England Executive Park;

telephone (617) 238–7113, fax (617)

238–7199.

SUPPLEMENTARY INFORMATION: On June

23, 1994, the Federal Aviation

Administration (FAA) issued priority

letter airworthiness directive (AD) 94–

14–11, applicable to Franklin Model

6A4–150–B3 and 6A4–165–B3

reciprocating engines, installed on the

following U.S. registered aircraft:

N6209M, N74231, and N752C. That

action requires teardown and analytical

inspection for engines certified to

operate on 91 or higher octane aviation

gasoline (avgas), and differential

compression test and examination of the

oil filter for engines certified to operate

on 80 octane avgas. That action was

prompted by reports of reports of

aviation gasoline (avgas) being

contaminated by Jet A fuel. After

investigation, the source of the

contamination has been determined to

be the refiner of the avgas. Through its

distribution system, the refiner

inadvertently caused Jet A fuel to be

loaded into distribution tanks intended

for avgas. Contaminated avgas from

these distribution tanks was then

shipped to local fuel distributors. The

FAA has determined that aircraft with

certain Franklin engines installed were

fueled with this contaminated mixture

between May 22 and June 2, 1994, at

Sacramento Executive (SAC) airport, or

between May 18 and June 2, 1994, at

Sacramento Metro (SMF) airport. The

list of U.S. registered aircraft specified

in the applicability paragraph of this AD

is based on investigation of fueling

records secured from the two affected

airports, which the FAA has determined

to represent the population of affected

engines. That condition, if not

corrected, could result in detonation

due to low octane, which can result in

severe engine damage and subsequent

failure.

This AD requires engines certified to

operate on 91 octane or higher avgas to

undergo a teardown and analytical

inspection for detonation damage, and

engines certified to operate on 80 octane

avgas to undergo inspection for

evidence of possible internal engine

damage. Engineering analysis of

operating these engines with avgas

contaminated with Jet A fuel indicates

that actual damage to the engine may

range from unnoticeable to very severe,

according to the duration of run, engine

power level, and level of contamination.

Damage may be characterized by

increased operating temperatures

resulting in damaged intake valves and

burned pistons, and excessive loads

imposed by detonation. Since internal

damage may not be assessed by any

other method, engines certified to

operate on 91 octane or higher avgas

must undergo a teardown and analytical

inspection and any parts showing signs

of detonation damage must be replaced.
2704 Federal Register / Vol. 61, No. 19 / Monday, January 29, 1996 / Rules and Regulations

Investigation revealed the lowest octane

level of the contaminated fuel to be 83

octane, therefore engines certified to

operate on 80 octane avgas need not

undergo a teardown and analytical

inspection unless evidence of internal

engine damage is present by the

required differential compression test

and examination of the oil filter for

metal particles. The refiner has advised

the FAA that it may pay for any

reasonable expense associated with the

inspection and/or disassembly in

accordance with the mechanic’s and

manufacturer’s recommendations.

Since an unsafe condition has been

identified that is likely to exist or

develop on other engines of this same

type design, this AD supersedes priority

letter AD 94–14–11 to revise incorrect

engine model numbers listed in the

priority letter AD.

Since a situation exists that requires

the immediate adoption of this

regulation, it is found 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

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public 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

under the caption ADDRESSES. 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 Number 95–ANE–70.’’ 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

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. A copy

of it, if filed, may be obtained from the

Rules Docket at the location provided

under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Incorporation by reference,

Safety.

Adoption of the Amendment

Accordingly, pursuant to 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), 40101, 40113,

44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

96–02–04 Franklin: Amendment 39–9489.

Docket No. 95–ANE–70. Supersedes AD

94–14–11.

Applicability: Franklin Model 6A4–150–B3

and 6A4–165–B3 reciprocating engines,

installed on the following U.S. registered

aircraft: N6209M, N74231, and N752C.

Note: This airworthiness directive (AD)

applies to each engine identified in the

preceding applicability provision, regardless

of whether it has been modified, altered, or

repaired in the area subject to the

requirements of this AD. For engines that

have been modified, altered, or repaired so

that the performance of the requirements of

this AD is affected, the owner/operator must

use the authority provided in paragraph (c)

to request approval from the Federal Aviation

Administration (FAA). This approval may

address either no action, if the current

configuration eliminates the unsafe

condition, or different actions necessary to

address the unsafe condition described in

this AD. Such a request should include an

assessment of the effect of the changed

configuration on the unsafe condition

addressed by this AD. In no case does the

presence of any modification, alteration, or

repair remove any engine from the

applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously. detonation due to

low octane, which can result in severe engine

damage and subsequent failure, accomplish

the following:

(a) For engines that are certified to operate

on only 91 or higher octane aviation gasoline

(avgas) within the next 2 hours time in

service (TIS) after the effective date of this

airworthiness directive (AD) perform an

engine teardown and analytical inspection,

and replace with serviceable parts as

necessary in accordance with the applicable

overhaul manuals.

(b) For engines that are certified to operate

on 80 octane avgas, within the next 2 hours

TIS after the effective date of this AD conduct

a differential compression test on all

cylinders in accordance with the applicable

maintenance manuals, and examine the oil

filter by cutting the oil filter apart and

spreading the filter paper out to look for

metal particles. If metal particles are present,

or if one or more cylinders shows

unacceptable compression as specified in the

applicable maintenance manuals, perform an

engine teardown and analytical inspection,

and replace with serviceable parts as

necessary in accordance with the applicable

overhaul manuals.

Note: Additional guidance for conducting

differential compression tests is contained in

paragraph 692 of Advisory Circular (AC) No.

43.13–1A, dated 1988.

(c) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Engine and

Propeller Standards Staff. The request should

be forwarded through an appropriate FAA

Maintenance Inspector, who may add

comments and then send it to the Manager,

Engine and Propeller Standards Staff.

Note: Information concerning the existence

of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine and

Propeller Standards Staff.

(d) Special flight permits may be issued in

accordance with sections 21.197 and 21.199
Federal Register / Vol. 61, No. 19 / Monday, January 29, 1996 / Rules and Regulations 2705

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the aircraft to

a location where the requirements of this AD

can be accomplished.

(e) This amendment supersedes priority

letter AD 94–11–11, issued June 23, 1994.

(f) This amendment becomes effective on

February 13, 1996.

Issued in Burlington, Massachusetts, on

January 11, 1996.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 96–1410 Filed 1–26–96; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 95–NM–19–AD; Amendment

39–9501; AD 96–03–04]

Airworthiness Directives; General

Dynamics (Convair) Model 240 Series

Airplanes, Including Model T–29

(Military) Airplanes; Model 340 and 440

Series Airplanes; and Model C–131

(Military) Airplanes; Including Those

Modified for Turbo-Propeller Power

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to various General Dynamics

(Convair) airplanes, that requires

revising the Airplane Flight Manual to

require that the flight crew limit the flap

settings during certain icing conditions

and air temperatures. This amendment

is prompted by reports indicating that

incidents involving uncommanded

pitch excursions have occurred due to

ice contaminated tailplane stall (ICTS)

that occurred during or following flight

in icing conditions. If flap settings are

increased for landing when conditions

for ICT S are present, elevator control

could be affected adversely and the

airplane could descend uncontrollably.

The actions specified by this AD are

intended to ensure that the flight crew

is advised of the potential hazard

related to increasing the flap settings

when conditions for ICTS are present,

and the procedures necessary to address

it.

EFFECTIVE DATE: February 28, 1996.

ADDRESSES: Information pertaining to

this rulemaking action may be examined

at the Federal Aviation Administration

(FAA), Transport Airplane Directorate,

Rules Docket, 1601 Lind Avenue SW.,

Renton, Washington; or at the FAA, Los

Angeles Aircraft Certification Office,

Transport Airplane Directorate, 3960

Paramount Boulevard, Lakewood,

California.

FOR FURTHER INFORMATION CONTACT:

Andrew Gfrerer, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130L, FAA, Transport Airplane

Directorate, Los Angeles Aircraft

Certification Office, 3960 Paramount

Boulevard, Lakewood, California 90712;

telephone (310) 627–5338; fax (310)

627–5210.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to various General

Dynamics (Convair) airplanes was

published in the Federal Register on

June 16, 1995 (60 FR 31648). That action

proposed to require revising the FAAapproved Airplane Flight Manual

(AFM) to require that the flight crew

limit the flap settings during certain

icing conditions and air temperatures.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

One commenter supports the

proposed rule.

One commenter supports the

proposed rule, but believes that an

allowance should be made for using a

setting of greater than flaps 30 after

icing conditions have been encountered

if outside air temperatures in the

landing area are well above freezing.

The commenter indicates that icing

conditions may be encountered at

cruising altitudes, but the ground

temperatures could be much warmer.

The commenter believes that there is

virtually no chance that ice would

remain on the tail. From the

commenter’s experience, all ice that has

collected on the wing leading edges,

engine nacelles, windscreens, and

windshield wipers will have

disappeared by the time the indicating

outside air temperature has reached +5

degrees Celsius on descent.

In light of these remarks, the

commenter suggests that the AFM

revision required by paragraph (a) of the

proposed rule be reworded as follows:

‘‘Flap selection is limited to a

maximum of 30 degrees after icing

conditions have been encountered if the

indicated OAT on approach is +5

degrees Celsius or lower; or if icing

conditions are anticipated during

approach and landing; or when the

outside air temperature is +5 degrees

Celsius or below and any visible

moisture is present.’’

The FAA does not concur with the

commenter’s suggestion. Operators

cannot generally assume that accreted

ice will not be present on wings and

tailplanes if the outside air temperatures

are above +5 degrees Celsius on

approach. Ice sublimation, melting, and

shedding are not only functions of

temperature, but also are dependent

upon other factors such as the nature,

size, and extent of ice accretion;

operation of ice protection systems; time

of flight in temperatures above freezing;

and airplane speed.

The commenter’s concern regarding

incurring a flap extension limitation

after encountering, and then departing,

icing conditions has merit. However, the

airplane must be free of ice before the

flaps are extended to greater than 30

degrees. Since ice can accrete on

tailplanes with a small leading edge

radius when there is no evidence of ice

accretion on the wings, a method of

visual inspection of the wings,

tailplanes, and/or proven ice detectors

or ice evidence probes would be

necessary to assure clean surfaces.

One commenter requests that the

proposed AD be withdrawn. The

commenter states that the airplane can

be operated quite safely within the

environment to which it is certified

when the anti-icing system is

operational and functioning, and when

that system is used in the manner in

which it was intended.

The FAA does not concur with the

commenter’s request. Test pilots of

Convair Model 5800 series airplanes

actually experienced evidence of ice

contaminated tailplane stall (ICTS)

during pushover maneuver flight tests.

(Model 5800 series airplanes are similar

to Model 340 series airplanes equipped

with turbo-prop engines.) For this

reason the type certificate holder agreed

with the FAA that a flap extension

restriction during operation in icing

conditions is necessary. The specific

flight test used to determine

susceptibility to ICTS is a pushover

maneuver to generate an increased angle

of attack on the horizontal tailplane.

This maneuver is performed with ice

shapes on the tailplane and flaps in

approach and landing positions, at

speeds from near approach to maximum

for the configurations. The test

procedure requires a push force

throughout the maneuver to zero load

factor. A force reversal would be

indicative of an elevator hinge moment

reversal caused by airflow separation

due to accreted ice and an increased

angle of attack due to pitch rate, and

would define the aircraft as susceptible

to ICTS. Because all affected Convair

airplane models have tailplane designs

that are similar to the model tested, this

AD requires a flap limitation.

The FAA has revised this final rule to

clarify that the unsafe condition