42364 Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 135

[Docket No. 28743; Amendment No. 135–

70]

RIN 2120–AG22

Commercial Passenger-Carrying

Operations in Single-Engine Aircraft

Under Instrument Flight Rules

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: The Federal Aviation

Administration (FAA) is amending the

conditions and limitations in part 135

for instrument flight rule (IFR),

passenger-carrying operations in singleengine aircraft. The rule will expand the

passenger-carrying provisions of the

current rule, add equipment

requirements, as well as maintenance

requirements to monitor engine

reliability, and remove the limited IFR

provisions of the existing rule for both

single and multi-engine aircraft. Visual

flight rules (VFR) flight into instrument

meteorological conditions (IMC) is the

most significant cause of fatal accidents

in Alaska and is a serious problem for

single-engine aircraft nationally. This

action will increase the safety of singleengine, passenger-carrying operations

by allowing planned instrument flight

in the IFR system and by imposing

certain other conditions and limitations.

DATES: The rule is effective May 3, 1998,

except for SFAR No. 81. Pending OMB

clearance on the paperwork

requirements, SFAR No. 81 is not

effective until the FAA publishes in the

Federal Register a document specifying

the effective date. Comments on the

clarification of §§ 135.163(f)(2),

135.411(c), and/or 135.421 (c) and (d),

including the paperwork requirements,

must be received on or before

September 5, 1997.

ADDRESSES: Comments on the

clarification of sections 135.163(f)(2),

135.411(c), and/or 135.421 (c) and (d),

including the paperwork requirements,

should be submitted to: Federal

Aviation Administration, Office of the

Chief Counsel, Attn: Rules Docket

(AGC–200), Room 915–G, Docket No.

28743, 800 Independence Ave., SW,

Washington, DC 20591.

FOR FURTHER INFORMATION CONTACT: Ms.

Katherine Hakala, Flight Standards

Service, Federal Aviation

Administration, 800 Independence

Ave., SW, Washington, DC 20591, (202)

267–8166/3760.

SUPPLEMENTARY INFORMATION:

Availability of Final Rule

An electronic copy of this document

may be downloaded, using a modem

and suitable communications software,

from the FAA regulations section of the

Fedworld electronic bulletin board

service (703) 321–3339), the Federal

Register’s electronic bulletin board

service (202) 512–1661), or the FAA’s

Aviation Rulemaking Advisory

Committee Bulletin Board service ((800)

322–2722 or (202) 267–5948). Internet

users may reach the FAA’s web page at

http://www.faa.gov or the Federal

Register’s web page a http://

www.access.gpo.gov/suldocs for

access to recently published rulemaking

documents.

Any person may obtain a copy of this

final rule by submitting a request to the

Federal Aviation Administration, Office

of Rulemaking, ARM–1, 800

Independence Ave, SW, Washington,

DC 20591, or by calling (202) 267–9677.

Communications must identify the

amendment number or docket number

of this final rule.

Persons interested in being placed on

the mailing list for future rules should

request from the above office a copy of

Advisory Circular No. 11–2A, Notice of

Proposed Rulemaking Distribution

System, which describes the application

procedure.

I. Background

Prior to October 10, 1978, passengercarrying, single-engine instrument flight

rule (SEIFR) operations were permitted

if an aircraft could descend to visual

flight rules (VFR) conditions in the

event of an engine failure. This

provision allowed operations in

instrument meteorological conditions

(IMC) or over-the-top of a ceiling, as

long as VFR conditions existed below

that ceiling (i.e., a buffer zone). In 1978,

part 135 was substantially revised for

passenger-carrying operations over the

top or in IFR conditions to require an

aircraft to be able to descend under VFR

if its engine fails (43 FR 46742; October

10, 1978). This revision also provided

for ‘‘limited IFR’’ operations which, if

VFR conditions were forecast within 15

minutes flying time, allowed flight in

IMC for the first 15 minutes of flight,

and thereafter only if those IFR

conditions were unforecast. Under the

current regulation, a pilot can operate in

IFR conditions if unforecast weather

conditions are encountered while en

route on a flight planned to be

conducted under VFR. The pilot can

make an IFR approach at the destination

airport if unforecast weather conditions

are encountered that do not allow an

approach under VFR. This rule had the

effect of eliminating the buffer zone

provisions, restricting planned flights

under IFR in IMC, and restricting VFR

over-the-top flights to scattered or

broken sky conditions. An exception to

the two pilot requirement, or autopilot

requirement, is provided for limited IFR

operations in § 135.103. Currently,

limited IFR can be conducted as a

single-pilot operation in aircraft with

nine or fewer passenger seats. Cargoonly, single-engine aircraft can operate

under IFR over the top without these

restrictions.

Since 1978, the FAA has received 12

petitions for exemptions from, or

amendments to § 135.181 to allow the

use of all or specific models of singleengine aircraft in passenger-carrying IFR

operations. Internationally, commercial

operators in several countries have

sought permission to conduct passenger

operations in IMC with single-engine

aircraft. Canada, following a cooperative

effort with the engine manufacturers,

aircraft manufacturers, and users that

produced a well-documented case, has

allowed SEIFR passenger-carrying

operations in turbine-powered airplanes

since February 1993, with a number of

specific requirements for equipment and

training. Other countries are also

considering permitting SEIFR

passenger-carrying operations.

In response to the petitions, the

Canadian action, and changes in

technology that have resulted in

increasingly reliable engines and aircraft

systems, the FAA asked its Office of

Integrated Safety Analysis to conduct a

study to determine if demonstrable

differences exist between single- and

multi-engine aircraft in visual

meteorological conditions (VMC) and

IMC. The study, Part 135 Single-Engine

Instrument Flight Rules Operations in

instrument Meteorological Conditions,

February 24, 1994, (available in the

docket) reviewed the basis for the

Canadian action and available data from

a number of sources on powerplant/

systems reliability and activity exposure

data.

In September 1994, the FAA asked the

Aviation Rulemaking Advisory

Committee (ARAC) to review the

Canadian policy on SEIFR, re-examine

FAA policies for commercial IMC and

night operations by single-engine

aircraft, determine conditions or

limitations that such operations should

meet, and recommend any changes. The

ARAC formed a working group that

included representatives of the FAA,

Transport Canada-Aviation, the

European Joint Aviation Authority

(JAA), Australian Civil Aviation, several

European national aviation authorities,
Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations 42365

aircraft and engine manufacturers, trade

associations, pilot unions, and

commercial operators. The committee

recommended that § 135.181 be revised

to permit SEIFR passenger-carrying

operations provided certain

requirements for equipment and

training were met. The ARAC proposal,

although not technically limited to a

particular type of aircraft, proposed

certain conditions that are met at

present only by turbine-powered

aircraft. The ARAC also recommended

approval of the Alaska Air Carrier

Association’s (AACA) petition for

exemption, which covers both turbinepowered and reciprocating engine

aircraft. Both the ARAC and the FAA

study focused on the issue of engine

reliability.

In 1995, the National Transportation

Safety Board (NTSB) completed a study

of operations in Alaska, Aviation Safety

in Alaska, (Safety Study NTSB/SS–95/

03, PB95–917006, November, 1995). The

NTSB noted that, unlike the rest of the

U.S., commuter airline service in Alaska

is ‘‘dominated by single-engine

airplanes powered by a reciprocating

engine operating under VFR and crewed

by one pilot.’’ After reviewing Alaska

aviation accidents from 1988 to 1993

(which include single and multi-engine

aircraft), the NTSB concluded that ‘‘VFR

flight into IMC that result in fatal

accidents continues to be the most

significant safety problem in Alaskan

aviation.’’ VFR flight in IMC in Alaska

accounted for 67 percent (6 of 9) fatal

commuter airline accidents and 47

percent (7 of 15) of the fatal air taxi

accidents. Overall, in Alaska, VFR flight

into IMC accounted for only 15 percent

of the total accidents, but 54 percent of

the fatal accidents. The NTSB

recommended that the FAA proceed

with rulemaking to allow SEIFR

passenger-carrying operations in

turbine-powered aircraft and evaluate

whether extending the rule to all singleengine aircraft would provide a positive

effect on safety.

Prior to the Alaska aviation study, the

NTSB conducted a study of emergency

medical service (EMS) helicopters

because their accident rate was twice

the rate experienced by part 135 on

demand helicopter operations and one

and one-half times the rate for all

turbine-powered helicopters. For the

report, Safety Study—Commercial

Emergency Medical Service Helicopter

Operations (NTSB 1988), the NTSB

investigated and evaluated 59 helicopter

accidents in the rapidly growing

commercial EMS helicopter industry.

The Board determined that marginal

weather conditions and inadvertent

flight into IMC remain the most serious

hazard that VFR helicopters encounter.

‘‘The Board believes that although the

IFR system is not designed optimally for

IFR helicopters and that the nature of

the EMS helicopter mission further

complicates this problem, the safety

advantages offered by IFR helicopters

flown by current and proficient pilots

are great enough that EMS programs

should seriously consider obtaining this

capability.’’

The Alaska Air Carriers Association

in its petition for exemption has stated,

and the NTSB study confirmed, that in

many areas, only single-engine aircraft

can be operated because of the

limitations of the landing strips, which

severely restrict the availability of air

transport in these areas. The petitioners

further stated that under the current

rule, unless clear weather is forecast

over the entire route from 15 minutes

from the departure airport to the

destination, passenger-carrying, singleengine commercial operations are not

permitted. In many areas, aircraft are the

only means of transportation; weather

forecasts, when available, rarely predict

continuing VFR conditions. Alaska, they

stated, was particularly disadvantaged

by the current rule.

The FAA reviewed accident data from

1983 to 1996 on both reciprocating and

turbine engines. Data indicated that

there were 67 accidents in on-demand

operations that involved VFR flight into

IFR conditions; single-engine aircraft

were involved in 75 percent of these

accidents. Although the number of such

accidents is known, the rate of such

accidents cannot be determined because

the FAA does not collect data on the

number of flights or flight hours for ondemand operations under part 135.

Based on its analyses, the FAA, on

December 3, 1996 (61 FR 64230), issued

a notice of proposed rulemaking

(NPRM) to amend part 135 to allow

passenger-carrying SEIFR operations

subject to the following conditions:

• Each certificate holder should

incorporate into their manufacturer’s

recommended maintenance program or

FAA-approved maintenance program an

engine trend monitoring program

including an oil analysis at each 100

hours interval and a record of the

findings; and

• Each aircraft should have two

independent electrical power generating

sources or a standby battery that can

maintain 150 percent of the minimum

electrical load for at least one hour to

operate navigation and communication

equipment.

The FAA proposed to eliminate the

limited IFR provisions, permitted under

the previous rule, for both single and

multi-engine aircraft. In addition, the

FAA sought comments on the need for

redundant power sources for gyroscopic

instruments. As the NPRM noted,

allowing SEIFR operations also imposed

on such operations all of the existing

requirements for IFR operations,

including additional equipment, an

autopilot or second pilot, increased

pilot experience, and more pilot

training.

In response to the NPRM, the FAA

received over 200 comments from

government entities, trade associations,

pilots, air carriers, manufacturers, and

individuals. Seven comments opposed

all or part of the proposed rule. Today’s

final rule reflects a consideration of the

comments received, which are

discussed in Section III.

II. Overview of the Final Rule

The rule promulgated today allows

SEIFR operations in both turbinepowered and reciprocating engines

subject to the following conditions:

• The certificate holder must

incorporate into its maintenance

program either the manufacturer’s

recommended engine trend monitoring

program, which includes oil analysis, if

appropriate, or an FAA approved engine

trend monitoring program that includes

an oil analysis at each 100 hour interval

or at the manufacturer’s suggested

interval, whichever is more frequent;

the certificate holder must maintain a

record of the results from these trend

monitoring programs in the engine

maintenance records.

• Each aircraft must have two

independent electrical power generating

sources each of which is able to supply

all probable combinations of continuous

inflight electrical loads for required

instruments and equipment; or in

addition to the primary electrical power

generating source, a standby battery or

an alternate source of electric power

that is capable of supplying 150% of the

electrical loads of all required

instruments and equipment necessary

for safe emergency operation of the

aircraft for at least one hour.

• Each aircraft must have two

independent sources of energy (with

means of selecting either), of which at

least one is an engine-driven pump or

generator, each of which is able to drive

all gyroscopic instruments and installed

so that failure of one instrument or

source does not interfere with the

energy supply to the remaining

instruments or the other energy source

unless, for single-engine aircraft in allcargo operations only, the rate-of-turn

indicator has a source of energy separate

from the bank and pitch and direction

indicators.
42366 Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations

Allowing SEIFR operations means

that any certificate holder conducting

such operations must meet all existing

requirements for IFR operations,

including those for equipment (e.g.,

vertical speed indicator, free-air

temperature indicator, heated pilot tube,

marker beacon receiver), crew (a second

pilot or autopilot), pilot training and

testing (proficiency check every six

months), and pilot experience (1,200

hours). The new requirements will

ensure that operators have an engine

trend monitoring program, as well as

written maintenance instructions. In

addition, the rule requires that aircraft

have redundant systems to provide

needed power to maintain critical flight

instruments as well as the necessary

navigation and communications

capability.

Because the FAA is deleting the

limited IFR provision, this rule will not

take effect until May 3, 1998. This will

allow operators the time to obtain the

required equipment, retrofit aircraft, and

revise their operations authority and

manuals. Limited IFR provisions will

remain in effect until that time. The

FAA is also adopting a Special Federal

Aviation Regulation (SFAR) No. 81 that

will allow operators who can meet the

requirements of the rule to begin SEIFR

operations prior to the effective date of

the rule, provided an information

collection is approved and an OMB

control number is assigned. Therefore,

the SFAR will not take effect until the

FAA has published a notice in the

Federal Register specifying the effective

date. It is anticipated that this notice

will be published within 60 days.

As explained in the NPRM, in the

past, the rationale against SEIFR

passenger-carrying operations centered

on the hazards of losing an engine.

Analysis indicates, however, a far more

significant accident category: Flight

under VFR into IMC. As discussed

above, a recent NTSB study of aviation

in Alaska indicated that VFR flight into

IMC caused a disproportionate number

of fatal accidents in part 135 operations

in that state. Multi-engine airplanes are

able to file and fly with passengers

under IFR, while single-engine airplanes

are only able (with few exceptions) to

carry passengers under VFR. Thus,

multi-engine airplanes have the

advantage of contact with ATC, position

following, en route and terminal

weather information, and the higher

altitude ensuring obstacle clearance and

radio reception in the IFR system.

Further, for IFR operations, part 135

requires additional fuel to be carried,

and more stringent weather reporting

requirements.

The FAA Administrator, in a

November 18, 1994 letter to pilots

(‘‘Winter Operations Emphasis Program

1994,’’ available in the docket),

expressed his concern about the number

of accidents that occur when pilots are

flying just below a low ceiling and

collide with the terrain. He stated that

one of the safest steps available was to

take advantage of the IFR system.

Aircraft flying at a published cruising

altitude that guarantees obstacle

clearance and radio reception have

considerably more time to glide to a

landing and maneuver to a safe landing

area, whether VMC or IMC, than those

flying below the ceiling.

The number of accidents involving

VFR flight into IMC is substantial. It is

concern with this safety hazard that

prompted the FAA to reconsider its

limitations on single-engine IFR flight

with passengers under part 135.

Additionally, the FAA has considered

the action of Canada that allowed

single-engine passenger-carrying IFR

under certain conditions, and the

petitions for exemption of the Alaska

Air Carrier Association and individual

operators. The FAA concluded that this

rule will reduce the number of accidents

by allowing operators to take advantage

of the IFR system and the significant

safety benefits it provides.

The FAA is aware that other nations

have either not allowed SEIFR or have

limited it to turbine-powered aircraft. In

the U.S., however, single-engine aircraft

are already allowed to conduct

passenger-carrying operations under

VFR in both day and night, and in IFR

conditions under the limited IFR

provisions, if they meet existing

requirements for IFR operations. Also,

single engine cargo operations are

presently authorized under IFR. The

limited IFR rules have created a

situation where pilots who encounter

IMC must either file an IFR flight plan

while en route or attempt to maintain

VFR by flying below the ceiling. The

FAA determined that safety would be

improved if operators could complete

adequate preflight planning and a file a

flight plan in advance, take advantage of

the IFR system while en route, and

maintain the obstacle clearance

provided by flying at higher altitudes.

Paragraph 5.1.2 of Annex 6, Part 1 of

the ICAO standard states, ‘‘Single

engine aeroplanes shall only be

operated in conditions of weather and

light, and over such routes and

diversions therefrom, that permit a safe

forced landing to be executed in the

event of engine failure.’’ The ability to

make such a safe landing will be

enhanced if the aircraft is in the IFR

system because it will be flying at a

higher altitude, which provides more

time to select a location and glide to a

landing. In addition, the aircraft would

be on an established route, with

guaranteed communications, with ATC

assistance readily available to select an

appropriate landing area, or advise/

direct search and rescue.

III. Discussion of Comments

The FAA received over 200 comments

on the SEIFR proposed rule. Seven of

the commenters oppose the rule; all of

these commenters propose changes to

the rule. The remaining commenters

state their support for the rule based on

the reasons given in the NPRM for the

proposal. A number of rule supporters

suggest changes to the rule, or requested

clarification of the technical

requirements.

A. General Opposition

The Air Line Pilots’ Association

(ALPA) and Raytheon Aircraft

Corporation both oppose the rule as a

whole on the grounds that VFR flight

into IMC is illegal and could be

prevented by other means. They state

that the FAA’s solution is inherently

unsafe. The commenters state that VFR

flight into IMC could be prevented by

increasing weather minimums or

imposing penalties for illegal

operations. They state that single-engine

aircraft will never be as safe as multiengine aircraft in the same operating

conditions. They further state that the

rule would increase the accident rate

and that FAA data indicate the accident

rate from propulsion system failure is

eight times higher for single-engine than

for multi-engine aircraft. A commenter

states that more than 18 percent of

single-engine propulsion failures occur

in IMC.

The FAA notes that the current VFR

standards represent a level of safety

which experience has shown to be

acceptable. Increasing VFR minimums

would not address the problem of VFR

flight into IMC. An increase in the

current VFR minimums could,

unnecessarily, restrict part 135

operators who are limited only to VFR

operations. Adequate penalties already

exist for violations of these regulations.

VFR flight into IMC is generally the

result of inaccurate weather reports or

unavailable forecasts. In deteriorating

conditions, pilots are forced to fly at

lower altitude to maintain VMC (or VFR

conditions). The FAA determined that

this rule will improve this situation by

requiring additional fuel reserves and

weather reporting necessary for IFR

operations; by providing immediate

assistance by ATC to the affected crew;

by guaranteeing radio communication
Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations 42367

from a minimum enroute altitude; by

providing quicker notification of search

and rescue assistance, all the while

having additional assistance in the

cockpit of another crewmember or

autopilot. Therefore, the FAA has

determined that this amendment will

create a safer flying environment than

the environment provided for in the

current rules.

The number of engines is only one

factor of many that leads to a successful

flight. The FAA is improving the total

operating environment with this

amendment. The single engine IFR

passenger-carrying operation will be a

planned operation (IFR preflight

planning of routes, weather, fuel, and

alternates), conducted in an ATC

controlled environment, with better

trained and qualified pilots, with

additional equipment (autopilot if not

two pilots, backup electrical and

pneumatic sources), and backed by an

improved maintenance program that

includes engine health monitoring. It

also is important to note that singleengine aircraft are already permitted

under the current regulations to carry

passengers during both day and night in

VFR conditions, and under limited IFR

conditions. Also, single engine cargo

operations are presently authorized

without having to meet the limited IFR

provisions. Thus, the FAA has already

endorsed the use of single-engine

aircraft in air transportation. This

amendment will make the total

operating environment for these aircraft

safer for the traveling public.

B. Turbine Versus Reciprocating

Engines

Although many commenters support

the extension of this rule to all singleengine aircraft, several commenters state

that the rule should be limited to

turbine-powered aircraft. These

commenters state that adequate data on

engine reliability exist only for turbinepowered aircraft. Transport Canada

states that the NPRM is ‘‘almost totally

lacking in the safeguards we included in

our rule to mitigate the risks inherent in

SEIFR.’’

Further, Transport Canada states that

it is not convinced that opening SEIFR

to all single-engine aircraft without

restriction will achieve the FAA’s safety

goals. Transport Canada also is not

convinced that trend monitoring for

reciprocating engines can provide the

same reliable information and warnings

that similar programs for turbine

engines provide. It states the belief that

only turbine-powered engines offer

sufficient reliability. The Joint Aviation Authority of

Europe (JAA) states that it has no

intention of including reciprocatingpowered engines in its proposal to allow

limited commercial travel and IMC

flight for single-engine aircraft. JAA’s

proposal will be limited to turbinepowered engines and require a flight

proficiency test, an area navigation

system, autopilot or two pilots, specific

approval on the air operator certificate,

a radio altimeter, airborne weather

equipment, a continuous ignition

system, a shoulder harness for

passengers, and supplemental oxygen

for pressurized aircraft. In addition,

terrain onto which a forced landing can

be made should be available at all

phases of flight. JAA states that ‘‘the

absence of any consideration of the

ability to carry out a forced landing in

the event of an engine failure seems to

the JAA not to accord with the Standard

in ICAO Annex 6, Chapter 5, Paragraph

5.1.2.’’

In response, the FAA understands the

concerns expressed by these

commenters, but upon consideration,

has determined that this amendment

should apply to both reciprocating and

turbine-powered aircraft. In examining

the types of accidents that were

occurring, the FAA determined that

there would be a positive benefit to

extending the rule to all properly

certificated airplanes. The amendment

addresses a number of factors, i.e.,

improved maintenance programs, more

detailed preflight planning, operations

in the IFR system, immediate assistance

from ATC, second pilot or autopilot,

and improved pilot training and

qualifications. When combined, the

FAA expects these improvements to

save lives. Additionally, in their

comment to the proposed rule change,

the NTSB supported the proposal

stating that the ‘‘Board accepts the

FAA’s conclusion that a positive effect

on safety would be obtained by

approving commercial, passengercarrying IFR operations in single-engine

airplanes powered by both turbine and

reciprocating engines, subject to the

additional equipment and operating

limitations.’’

SEIFR operations under part 135 are

not without restrictions. Operators who

choose to use single-engine aircraft in

part 135 passenger-carrying operations

must comply with all the additional

equipment and training requirements

that apply to IFR operations. In response to JAA’s concerns

regarding harmonization, the FAA fully

supports harmonization efforts with

JAA and Transport Canada, where

appropriate. JAA’s proposal is

concerned largely with a European

aeronautical and geographical

environment. The FAA has required in

this rulemaking many of the items

proposed by JAA; however, the FAA

believes that JAA’s full proposal would

have the effect of deterring participation

of operators of single-engine part 135

aircraft in the IFR system and by so

doing, contribute to the type of safety

situation that this rule seeks to improve.

Additionally, the FAA recognizes that

Transport Canada has taken the lead

with allowing operations with single

engine turbine aircraft. In fact, the FAA

considered Transport Canada’s work as

it developed its proposal. The FAA will

continue to support harmonization

efforts to the maximum extent

practicable; however, because of its

large aircraft population operating

under part 135 and its extensive IFR

system, the FAA will continue to

address aviation safety issues in the

United States in light of its unique

situation. The FAA notes, however, that

to the extent that Canada’s aviation

rules preclude the use of single-engine

aircraft powered by reciprocating

engines in IFR operations, then such

U.S. certificated single-engine

operations may not be able to conduct

single engine, passenger-carrying

operations in Canadian airspace.

Therefore, the FAA intends to file a

difference to the single-engine

operational standard of Annex 6,

Chapter 5, Paragraph 5.1.2. to become

effective upon the effective date of the

SFAR.

C. Equipment Requirements

Independent Generators/Second Battery

Requirement

A number of commenters state that it

would be too costly for electrical

systems to provide a second battery

capable of supplying 150 percent of the

minimum electrical load for a least one

hour, as proposed. One commenter says

that such a battery would weigh 30

pounds and result in a more complex

electrical system increasing the

probability of electrical failure. Another

commenter writes that he does not

know of such a system that is widely

available, reliable, and reasonable in

cost. Instead of requiring a standby

battery system, the commenter proposed

requiring an ‘‘easily noticeable warning

light,’’ which indicates immediately that

the power generating source is failing.

Several commenters suggest a

requirement to carry a handheld

transceiver, perhaps with an alkaline

battery pack, to address concerns about

the loss of the airplane battery or

alternator/generator. In general,

commenters who disagree with the

requirement for a backup power supply

argue that there is enough redundancy

currently required.
42368 Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations

In response to comments, the FAA, in

the final rule, requires either two

independent electrical generating

sources, or a standby battery or an

alternate electrical source to serve as a

second power source (as opposed to

specifying only a battery) if that source

can supply 150% of the electrical loads

necessary for emergency operations of

the aircraft for at least one hour. This

requirement introduces redundancy for

the generator and alternator and ensures

that, if a generator or alternator fails, the

aircraft will still be able to use certain

equipment for a period of time in which

to make a safe approach and landing.

A handheld transceiver is not on the

aircraft equipment list; because such

equipment is not permanently installed,

its presence on an aircraft could not be

assured and, therefore, it would not

meet the regulatory requirement. In

reference to the comment

recommending a warning light system,

the FAA has determined that such a

system provides no redundancy and

would only identify a failure as it is

happening rather than providing the

aircraft with electrical power for needed

equipment for at least one more

additional hour after the failure of the

primary system has occurred.

Further, the FAA believes that an

alternate electrical source, such as a

standby battery, that would be approved

for use in a single-engine IFR will be a

cost effective means of providing a level

of safety equivalent to an aircraft with

a dual electrical system. The FAA has

used the phrase ‘‘alternate source of

electric power’’ in this amendment.

Although the FAA envisions that

alternate source to be a battery or an

electrical storage unit, the wording

provides for future technology that may

replace a simple battery.

The NPRM proposed, as an alternative

to having two independent electrical

generating sources installed on the

aircraft, a single generating source and

a standby battery capable of supplying

150% of the minimum electrical load

for at least one hour to operate

navigation and communication

equipment. Commenters raised

questions as to what was meant by the

term ‘‘minimum electrical load’’ as it

pertains to the capacity of the standby

battery. Upon further review, the

Agency recognizes that the proposed

§ 135.163(f)(2) regulatory language did

not comport with its intent regarding

the electrical loads that the standby

battery must be capable of providing.

Therefore, in this final rule, the

Agency is clarifying its intent that the

standby battery be capable of supplying

150% of the electrical loads for all

required instruments and equipment

necessary for the safe emergency

operation of the aircraft for one hour.

This is consistent with the redundancy

requirements specified for multiengine

aircraft in § 135.163(g). The FAA further

recognizes that in an actual emergency

situation, the pilot will shed electrical

loads to the minimum required for safe

operation. Required instruments and

equipment could include single

navigation and communication

equipment, but could also include other

equipment necessary for the safe

operation of the aircraft in the actual

environment, such as pilot heat or

instrument lighting. The FAA is

therefore deleting both the phrase

‘‘minimum’’ and ‘‘to operate navigation

and communication equipment’’ from

the regulatory language to clarify that

the battery capacity is not limited solely

to the capacity needed to operate

navigation and communication

equipment, but other necessary

equipment as well. Thus, should an

operator choose not to install two

independent electrical power generating

sources on the aircraft, this alternate

minimum electrical power source will

provide the necessary system

redundancy for safe emergency

operation of the flight.

The FAA further finds that although

it did not propose this precise language

in the NPRM, it is unnecessary and not

in the public interest to delay the entire

single-engine IFR rulemaking on this

minor technical issue. Nevertheless, the

FAA invites comment on the final

regulatory language in § 135.163(f)(2).

Redundant Power Source for Gyroscopic

Instruments

The FAA specifically sought

comments on whether a redundant

power source for gyroscopic

instruments is needed. One commenter

responds that requiring dual enginedriven, pneumatic pumps would go a

long way to precluding loss of air-driven

gryos. If both pumps were lost because

the engine stopped, the battery should

last long enough to allow the aircraft to

glide to a landing. One commenter

states that French IFR rules achieve

redundant gyroscopic instruments with

one attitude indicator and a second

attitude indicator or a turn indicator and

a slip indicator powered by a source

independent of the first attitude power

source. Another commenter states that a

third attitude indicator should be

installed with at least 3-minute selfcontained electrical source independent

of the aircraft’s main electrical system.

The NTSB recommended a requirement

for a redundant source of power for

attitude gyroscopic instrumentation.

The Board stated that despite

requirements for partial panel training,

the fatal accident record indicates that

many pilots have experienced difficulty

maintaining aircraft control during

actual partial panel situations. Another

commenter, however, states that

because there are so few system failures

in IFR flight, redundant systems for

gyroscopes are unnecessary.

By this amendment, the FAA has

adopted the proposed requirement for

redundant power sources for gyroscopic

instruments to the final rule. Although

the NPRM did not contain the

regulatory language, the Agency

proposed the redundant power source

requirement in the preamble. The FAA

recognized that the failure of the

vacuum/pressure pump of the

pneumatic system during IFR in IMC

can lead to spatial disorientation of the

pilot and loss of aircraft control. The

redundancy or the pneumatic system

will put single-engine aircraft systems

on parity with existing twin-engine

aircraft. Because the FAA proposed

redundancy for passenger-carrying

operations, but not for all-cargo

operations, the final rule requirement

for redundancy of power source for

gyroscopic instruments is limited to

passenger-carrying operations.

Autopilot/Co-pilot Requirement

Several commenters state that the

proposed rule does not substantiate the

need for two pilots or a single pilot with

autopilot. There are concerns because

the vast majority of single engine

aircraft do not have an autopilot

installed that meets the requirements of

§ 135.105, and retrofitting such aircraft

may cost up to $20,000 and add up to

30 pounds to the empty weight of an

aircraft. In addition, according to the

commenter, if another crewmember is

added to comply with the regulation,

one less seat would be available on the

small planes, which would be a ‘‘severe

economic burden.’’ Another commenter

states that the FAA should allow twoaxis autopilots; a requirement for a

three-axis autopilot would eliminate

most single-engine aircraft currently

equipped with autopilots.

In response, the FAA disagrees that an

autopilot or second pilot is not needed.

The complexity and workload in IMC is

such that a three-axis autopilot as

opposed to a two-axis autopilot, or

second pilot is necessary for safety in air

transportation. Section 135.105

currently establishes a standard for an

autopilot capable of operating the

aircraft controls about three axes.

Concerning the comment on weight

penalty and the cost issue, the FAA has

determined that these requirements, as

well as the other requirements for
Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations 42369

equipment, training and checking,

operations, maintenance, etc., are based

on experience and are considered

necessary for safety. The FAA has

determined that they remain valid for

any air carrier involved in commercial

passenger-carrying operations.

Therefore, the FAA is adopting the

autopilot or second pilot as proposed.

Other Equipment

Commenters suggest other equipment

that should be required for SEIFR

operations. One commenter states that a

radar altimeter should be required

because it shows actual height above the

terrain. Another commenter states that

for planes with six or more passengers,

the FAA should mandate an emergency

cockpit checklist, a cockpit voice

recorder, and weather radar. For

turbine-powered airplanes, TCAS and

GPWS should be required when

carrying six or more passengers. Area

navigation systems provide an

additional margin of safety where radar

coverage is minimal. A third commenter

states that the NPRM does not

adequately address pitot system antiicing. Any flight where flight

temperatures will be below 40° F should

require dual heated pitot systems to

ensure that the pilot will have airspeed

and static system operation in IMC. Fuel

tank vents and stall warning systems

need to be ice protected. Windshield deice is needed for winter operations in

Alaska. The commenter also suggests

self-powered attitude indicators should

be added to single-engine aircraft used

for SEIFR operations.

To respond, the FAA notes that radar

altimeters are only required for Category

II and III operations. As for the

emergency cockpit checklist, a cockpit

voice recorder, weather radar, TCAS,

GPWS, and area navigation systems, the

FAA has decided that this equipment is

not necessary for the planned operations

affected by this rule.

Regarding the comment on icing,

flight into icing conditions is already

prohibited by § 135.227 unless the

aircraft is adequately equipped. This

rule does not change the equipment

requirements for flight into icing

conditions. Also, this rule does not

relieve an operator from having an

aircraft certified for flight into icing

conditions, if those operations are

anticipated.

D. Oil Analysis/Maintenance/Trend

Monitoring/Engine Health

Several commenters are concerned

about the oil analysis requirements.

Several letters mention that while oil

analysis as part of a maintenance

program may be justified, expensive

engine maintenance should not be

required based solely on this one

parameter. According to the commenter,

one ‘‘bad’’ sample is not sufficient

reason for maintenance until further

analysis is performed. Oil samples may

be misleading because it is possible to

have sample contamination; as the

commenter noted, a single operation on

a dusty day with the carburetor heat left

on accidentally allowing unfiltered air

into the engine may create a

contaminated sample. The commenter

suggests that other tools, such as

compression checks and borescopes,

should be used in conjunction with oil

analyses.

Another commenter states that oil

analysis has never enabled him to

predict, and therefore avoid, engine

problems. He gave an example of one

instance where a turbocharger broke

down, filling the engine’s oil screen

with metal. After contacting the oil lab

to find out why the oil analysis tests had

not predicted the failure, the lab

indicated to him that the particles of

metal in the oil were ‘‘too big’’ to be

detected by regular analysis.

One commenter says that those in the

oil analysis business are concerned

about their liability insurance if their

opinion is mandated rather than

advisory. Another commenter writes

that oil analysis should not be required

at each 100 hours of inspection, but

rather at 100 hours of operations

because not all oil changes are made at

100-hour inspections. Other

commenters suggest replacing ‘‘oil

analysis’’ with ‘‘trend monitoring and/or

oil analysis.’’ Finally, two commenters

suggest requiring ‘‘oil analysis’’ and an

oil and filter change every 50 hours

rather than 100 hours. Another

commenter states that spectrographic oil

analysis is not a predictor of fatigue

failures, which are the most common

cause of piston-engine power loss.

FAA has determined that engine

health trend monitoring can play an

important part in preventive

maintenance by providing an early

warning of potential problems. The final

rule gives operators the option of

adopting the manufacturer’s trend

monitoring program or an FAAapproved trend monitoring program that

includes oil analysis. The FAA is

currently updating its advisory

materials on trend monitoring programs

(AC 21–105A, ‘‘Engine Power Loss

Accident Prevention,’’ dated 11/20/80).

While the FAA recognizes that the

possibility exists for misleading oil

analyses, each laboratory analysis report

must be treated individually and in

conjunction with previous reports. If the

data indicate a possible problem exists,

further inspection and/or maintenance

is necessitated. This approach is

consistent with the current practice of

inspection if one of the engine’s

cylinders had a bad compression

reading because carbon deposits were

keeping a valve from properly seating.

FAA has determined that a

spectrographic oil analysis, properly

performed, provides the owner/operator

with a reliable, advance warning of a

potential failure based on the amount of

metal and bearing material in the oil

sample. Although contamination can

occur at any stage, in a comprehensive

maintenance inspection program, oil

analysis will provide useful trend

information. The FAA agrees with the

comment that oil analysis will not

always give advance warning of fatigue

failures, such as crankshaft separation,

but neither do other inspection

techniques, such as borescope

inspections and compression tests.

Regarding the recommendation to

change the interval of oil sampling from

100 hours to 50 hours, the FAA notes

that 100-hour interval is considered an

‘‘industry standard.’’ Under the final

rule, operators must follow the

manufacturer’s monitoring program

recommendations if they call for more

frequent checks.

The FAA also recognizes that oil

analysis may not be applicable to

certain engine types, e.g. Pratt and

Whitney PT–6. Therefore, in the final

rule, the operator is given the option to

choose between the manufacturer’s

published trend monitoring program,

which may or may not contain a

provision for oil analysis based on the

engine type and design, or the FAAapproved program that must include oil

analysis. Published manufacturer’s

trend monitoring programs are available

for turbine engines, however, the FAA

is not aware of any published trend

monitoring program for reciprocating

aircraft.

To clarify the recordkeeping

requirements, the FAA has added a new

§ 135.421(e) to require the recordation

and maintenance of the results of each

test, observation, or inspection required

by the applicable engine monitoring

program in the engine maintenance

records. Although the FAA proposed a

recordkeeping requirement for the

engine trend monitoring, the FAA

requests comment on the modification

to the recordkeepng requirement to be

codified in § 135.421(e). The required

recordation is subject to OMB approval,

as required by the Paperwork Reduction

Act. An information collection control

number will be assigned for it if and

when OMB approval is given; that
42370 Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations

number would be listed in part 11,

subpart F, of Title 14.

E. Training

One commenter suggests that training

should emphasize partial panel

operations and systems failure

recognition; such training could be

included in part 135 training manuals.

Another commenter states that an ATP

certificate should be required for SEIFR

operations. Commenters also suggest

that simulator training and a six-month

IFR check should be required.

The FAA agrees with the commenter

that additional emphasis and checking

in partial panel and system failure

recognition are necessary. Existing

regulations require training in systems

failures. The FAA will review and

update its handbooks and training

related material to ensure that partial

panel operations are evaluated on the

instrument competency checks for the

affected operators and that proper

attention is given when operators’

training programs are approved and

reviewed.

In addition, the FAA notes that an

ATP certificate is required for pilot-incommand positions on large airplanes

usually operated under part 121. The

experience and skill level required for

single-engine air transportation under

IFR are not equivalent to those required

for large transport category airplanes.

The FAA maintains that a commercial

pilot certificate and appropriate ratings

are sufficient qualification for

operations conducted under this rule;

part 135 requires 1,200 hours of flight

time for IFR operations. On simulator

training, the FAA notes that part 121

does not require simulator training.

Simulators are not available for most of

the types of aircraft that will operate

under this rule. For those aircraft that

have simulators available, operators are

encouraged to use them. Also, some

training may be accomplished in a

training device (§ 135.347). The FAA

does not believe that required simulator

training is necessary for adequate safety

for the anticipated operations. Last, a

six-month instrument proficiency check

is already required (§ 135.297) by the

existing regulations.

F. Removal of Limited IFR

Several commenters believe that the

elimination of the present ‘‘limited IFR’’

rules would not be in the best interest

of safety. They believe that operations in

limited IFR conditions allowed by

§§ 135.103 and 135.181 should still

apply to single-engine airplanes without

autopilots because the rules allow a

qualified pilot to make an approach if,

due to unforecast weather, the intended

destination goes below VFR minimums.

Another commenter does not favor

eliminating these sections because

pilots would lose the ability to climb

out of the low level fog layer that often

persists at some airports during the

morning hours of the day. One

commenter argues for maintaining the

‘‘limited IFR’’ rule because it is safer to

offer the ability to operate under limited

IFR rather than to force a pilot to scud

run in and out of an uncontrolled field,

or face delays at a tower controlled

field, all the while watching the weather

conditions worsen. Another commenter

suggested amending § 135.103 to

exempt the autopilot for this section.

Current data, as discussed in the

NPRM, for on-demand Part 135

accidents involving single-engine

aircraft indicate that poor inflight

planning and decision-making, and

other weather-related errors resulting

from attempts to maintain VFR flight are

the major causes of accidents. While the

possibility of a failure of the single

engine exists, the FAA has, it believes,

reduced that possibility further by

additional maintenance requirements.

The possibility of pilot mishandling has

also been reduced, in the judgment of

the FAA, by emphasizing training in

partial panel emergency procedures and

system failure recognition when

combined with equipment

redundancies.

As mentioned above, the FAA is

improving the total operating

environment with this amendment. A

single-engine passenger-carrying

operation will be a planned operation

(IFR preflight planning of routes,

weather, fuel, and alternates),

conducted in an ATC controlled

environment, with better trained pilots,

with additional equipment (autopilot if

not two pilots, redundant electrical and

vacuum systems), backed by an

improved inspection program that

includes engine trend monitoring.

Therefore, the FAA has not retained the

limited IFR rule because the FAA

concluded, based on available data, that

planned flight under IFR provides a

higher standard of safety than

unplanned flight under the limited IFR

rule.

G. Weather and Terrain Issues

Transport Canada states that flight

under IFR requires that the aircraft be

certified for flight into known icing for

at least the northern U.S.; few existing

single-engine aircraft in commercial

service are so certified. Another

commenter states that icing is a greater

problem than VFR flight into IMC. The

greater number of accidents due to

inadvertent encounters with icing will

more than offset any improvements in

the VFR to IMC accident rate.

Reciprocating engine aircraft

certification rules do not require a

demonstration of any ability to continue

to operate in icing conditions. In

addition, a few commenters state the

SEIFR over mountainous terrain should

be barred.

The FAA recognizes that authorizing

an aircraft to operate in IFR conditions

neither converts an aircraft to ‘‘allweather,’’ nor allows it to do anything

for which it is not certificated or

equipped. Under § 135.227, operators

using aircraft not certified for known

icing conditions may not operate in

those conditions. An aircraft that does

not meet the requirements for flying in

icing conditions may not be operated in

those conditions. Additionally, the FAA

notes that part 135 operators can already

operate under IFR in U.S. airspace using

aircraft that are not certified for known

icing as long as the operations

anticipated are outside of known icing

conditions.

Single-engine aircraft limited by

service ceiling or lack of pressurization

or oxygen will not be capable of using

the IFR system over some mountainous

terrain. In addition, the FAA notes that

finding a suitable landing place in

mountainous terrain, if a forced landing

is necessary, may not be very much

different from finding a suitable landing

place in a wide, densely populated area.

Single engine aircraft are not presently

restricted from either area. Thus, single

engine operations addressed in this

amendment will not be so restricted

either.

H. National Application of the Rule

A commenter suggests that the FAA

should limit all SEIFR operations to

only Alaska (turbine or reciprocating

engine) or, at least, limit SEIFR with

reciprocating-engine aircraft to only

Alaska. A commenter states that if

specific operations in remote areas

require exemptions, these should be

handled on a case-by-case basis, not by

adopting a national standard. Several

commenters state that this rule will

result in operators trading in multiengine aircraft and replacing them with

reciprocating engine, single-engine

aircraft.

The FAA considered the conditions of

weather and terrain in Alaska to be a

‘‘worst-case’’ operating environment.

Authorization in the regulations for use

of single-engine air transportation under

IFR in Alaska would justify singleengine air transportation under IFR in

the contiguous U.S. where operating

conditions are generally less severe. The

FAA’s regulatory evaluation indicates
Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations 42371

that this rule will create a net safety

benefit in the other 49 states as well as

Alaska. Exemptions are handled on a

case-by-case basis; however, the

rationale that the FAA would use to

justify an exemption would also apply

to all similarly-situated operators.

The FAA does not expect the

operators currently flying multi-engine

aircraft will switch to single-engine

aircraft simply because of this rule

change. Decisions about the type of

aircraft to operate are complex.

Operators must weigh numerous factors

when selecting aircraft, for example,

aircraft availability and age, customer

base, and geographical location.

Whatever choice operators make, the

FAA remains convinced that the rule

will increase safety of single-engine,

passenger-carrying operations.

I. Other Comments

Several comments support the ARAC

proposals. One commenter states that

the FAA received only 12 petitions for

exemptions since 1978, which is not a

significant number. Finally, one

commenter states the proposal would

result in slower, single-engine aircraft at

metropolitan airports, taxing the ATC

system, and in more inexperienced

pilots flying in hazardous conditions.

To overcome these problems, they

suggest that any aircraft that cannot

maintain 140 knots on final approach

should be excluded from Class B

airspace and that pilot qualifications

should include 2,000 hours of flight

time.

The FAA commends the ARAC for its

detailed work on the SEIFR proposal; as

is evident, the ARAC proposal formed a

basis for this action. In fact, the FAA

notes that this final rule incorporates a

number of the ARAC proposals. Other

ARAC proposals are not needed because

they duplicate existing requirements.

The ARAC proposals, although not

technically limited to a particular type

of aircraft, cited conditions that are met

at present by only turbine-powered

aircraft. The ARAC also recommended

that the FAA grant the Alaska Air

Carriers Association’s petition for

exemption, which covers all singleengine aircraft.

FAA rulemaking is not contingent

only upon public petition. In the case of

this rule, the petitions for exemption,

one of which was submitted by a trade

association, were only part of an overall,

growing awareness by industry and

FAA that the limited IFR rule was no

longer serving its original purpose and

that the better safety alternative would

be to allow all qualified part 135

operators to use the IFR system from

departure to termination of the flight.

Finally, the FAA is unaware of any

evidence that this rule would place an

excessive burden on the ATC system or

result in delays in the terminal area.

IV. Maintenance of Required

Equipment

Section 135.411 requires an operator

of an aircraft type certificated for 9 or

fewer passengers to have that aircraft

maintained, at a minimum, in

accordance with parts 91 and 43 of Title

14. The maintenance is performed on

the basis of 100-hour and annual

inspections, as those inspections are

described in part 43, appendix D. For an

aircraft type certificated for 9 or fewer

passengers, § 135.411 also accepts an

approved aircraft inspection program

(AAIP), as described in § 135.419.

Section § 135.419(a) provides that,

when the FAA finds that the aircraft

inspections required under part 91 are

not adequate to meet part 135, the FAA

may amend the operator’s operations

specifications to require an AAIP.

Section § 135.419(f) provides that, when

the FAA finds that revisions to an AAIP

are necessary for the continued

adequacy of the program, the operator

must, after notification from the FAA,

make the necessary revisions. Longstanding rules, therefore, enable the

FAA to make even major adjustments to

an operator’s maintenance program that

are necessary to maintain the level of

safety appropriate for carrying

passengers or cargo for compensation or

hire.

Section 135.421(a) describes

additional maintenance requirements

for each operator of an aircraft type

certificated for 9 or fewer passengers; it

requires the operator to comply with the

manufacturer’s recommended

maintenance program, or with an AAIP,

for each aircraft, engine, propeller, rotor,

and item of emergency equipment. In

Notice 96–14, the FAA proposed to add

paragraph (c) to § 135.421 to require the

single engine aircraft operator to

incorporate into its manufacturer’s

recommended maintenance program or

AAIP, an engine trend monitoring

program that includes a 100-hour oil

analysis and record of findings.

The equipment required under

§ 135.105 and new § 135.163 (f) and (h)

will frequently be installed in

accordance with a supplemental type

certificate (STC); the holder of that

certificate may be required by 14 CFR

§ 21.50 to furnish instructions for

continued airworthiness (ICAW), in

which case, it is important that the

operator maintain the equipment in

accordance with those instructions to

maintain the level of safety appropriate

for carrying passengers for

compensation or hire. It is imperative

for each part 135 operator, no matter

what the method of approval of the

installation, to have the equipment

required by this rule maintained to the

level of safety appropriate for carrying

passengers for compensation or hire.

Accordingly, the FAA has decided to

adopt new § 135.421(d). New

§ 135.421(d) will require the operator to

ensure that the equipment required by

§ 135.105 and new § 135.163 (f) and (h)

is maintained in accordance with

written maintenance instructions that

will provide a level of safety equivalent

to ICAW. If the manufacturer provides

ICAW, the operator may use those; to

deviate from the ICAW, the operator

will be required to obtain FAA

approval. New § 135.421(d) applies to

operators who have 100-hour and

annual inspection based programs, and

operators who have AAIPs. Therefore, if

operator does not utilize the applicable

manufacturer’s maintenance manual or

instructions for continued airworthiness

prepared by the manufacturer, then it

must have written maintenance

instructions, acceptable to the

Administrator, containing the methods,

techniques, and practices to maintain

the equipment required in §§ 135.105

and 135.163 (f) and (h).

Although this modification to the

maintenance requirements was not

explicitly stated in Notice 96–14, the

FAA has decided to adopt it in this final

rule. As explained above, long-standing

rules enable the FAA to make necessary

adjustments to an operator’s

maintenance program. Furthermore,

operators should realistically expect to

be required to properly maintain all

equipment that is critical to SEIFR

operations. The FAA has determined

that many operators already have the

items of equipment installed in their

aircraft, and are maintaining those items

in accordance with instructions that are

not stated in the amount of detail

necessary for the level of safety

expected for SEIFR operations. New

§ 135.421(d) will require those

instructions to be written and

acceptable to the Administrator.

Because the FAA did not explicitly

propose § 135.421(d), the FAA invites

comment on that section’s final

regulatory language. The required

written maintenance instructions are

subject to OMB approval, as required by

the Paperwork Reduction Act. An

information collection control number

will be assigned for them if and when

OMB approval is given; that number

would be listed in part 11, subpart F, of

Title 14.

Section 135.411 requires an operator

of an aircraft type certificated for 10 or
42372 Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations

more passengers to have that aircraft

maintained in accordance with a

program that meets the requirements of

§§ 135.415, 135.417, and 135.423

through 135.443. That program is

referred to as a continuous

airworthiness maintenance and

inspection program (CAMP). Section

135.425(c) requires that a CAMP ensure

that each aircraft released to service has

been properly maintained for operation

under part 135. Section 135.427(b)

requires the CAMP to include the

programs required by § 135.425 that

must be followed in performing

maintenance, preventive maintenance,

and alteration of the operator’s aircraft,

including the airframe, engines,

propellers, rotors, appliances,

emergency equipment, and parts.

Instructions for maintaining the

equipment required by §§ 135.105 and

135.163 (f) and (h) will be incorporated

into operators’ CAMPs.

V. Section-by-Section Discussion of

Changes

Special Federal Aviation Regulation

(SFAR) No. 81 is added to allow

operators who can meet the

requirements of this rule before the

effective date to begin SEIFR operations.

The SFAR is not effective until the FAA

publishes a notice specifying the

effective date in the Federal Register.

The SFAR terminates on the effective

date of the Commercial PassengerCarrying Operations in Single-Engine

Aircraft Under Instrument Flight Rules

rule.

As proposed, § 135.101 is revised to

eliminate the reference to § 135.103,

which is deleted, and to delete the word

‘‘conditions’’ after IFR. Deletion of the

word ‘‘conditions’’ clarifies that any

operation for which an IFR flight plan

is filed must have a second pilot or an

autopilot, even if the flight can be

conducted in VFR conditions.

As proposed, § 135.103 is deleted

because it is no longer needed.

Section 135.163 is revised to add, for

multi-engine aircraft, reference to

alternators. For single-engine aircraft, a

requirement is added for two

independent electrical power generating

sources or a standby battery or alternate

source of electric power. A requirement

is also added for a redundant energy

system for gyroscopic instruments; the

existing exception in paragraph (h) for

single-engine aircraft is not limited to

single-engine aircraft in all-cargo

operations.

As proposed, § 135.181 is revised by

dropping all of the limited IFR

conditions. Only the performance

requirements for multi-engine aircraft

and over-the-top requirements remain.

Section 135.411 is revised to add a

reference to § 135.421 as it pertains to

the maintenance requirements for single

engine passenger-carrying aircraft under

IFR.

Section 135.421 is revised to add the

requirement for engine trend monitoring

for aircraft used in passenger-carrying

SEIFR operations, and the requirement

for written maintenance instructions,

acceptable to the Administrator, for the

equipment required in §§ 135.105, and

135.163 (f) and (h).

Regulatory Evaluation Summary

The Federal Aviation Administration

(FAA) is updating and revising the

regulations to allow single-engine,

passenger carrying aircraft to operate

under the instrument flight rules. The

rule will reduce the incentive for

operators to conduct low altitude

operations under marginal weather

conditions. However, this rule will also

require operators to meet the more

stringent requirements for such flights

including additional aircraft equipment.

The cost of this final rule is estimated

at $170.3 million ($127.6 million,

discounted). The most costly provision

is on the requirement for an autopilot,

which is estimated at $94.9 million

discounted and represents about 74.3

percent of the total. The FAA concludes

that the expected quantitative benefits

will be $354.6 million or $249.1 million,

discounted. If the rule is 75 percent

effective in reducing fatalities and

injuries, then the expected quantitative

benefits will be $284.3 million or $199.5

million discounted over ten years. The

benefits estimate should be considered

low because the added equipment, etc.

required for single-engine aircraft

should result in fewer overall fatalities.

The benefits analysis does not take this

into account.

If fewer disruptions, cancellations,

etc. were considered a cost-savings

instead of a benefit, then both the

benefit estimate and the cost estimate

should be reduced by $156.9 million

($110.2 million discounted). The cost of

the rule, net of these costs savings, will

be $13.4 million or $17.4 million,

discounted, and the benefits of this rule,

namely safety benefits (assuming 75

percent effectiveness), will be $127.7

million or $89.3 million discounted

over ten years. While the discounted

costs and benefits are lower than the

undiscounted costs and benefits,

respectively, the discounted net costs

are higher than the undiscounted net

costs.

Under the guidelines presented in

FAA Order 2100.14A, the FAA has

determined that the final rule will not

have a significant economic impact,

positive or negative, on small operators.

This final rule is not expected to have

any impact on trade opportunities for

U.S. firms doing business overseas or

foreign firms doing business in the

United States. The final rule will

primarily affect U.S. operators of aircraft

for hire that provide domestic service.

This final rule does not contain any

Federal intergovernmental or private

sector mandate. Therefore, the

requirements of Title II of the Unfunded

Mandates Reform Act of 1995 do not

apply.

Regulatory Flexibility Assessment

The Regulatory Flexibility Act of 1980

(RFA) was enacted by Congress to

ensure that small entities are not

unnecessarily or disproportionately

burdened by Federal Regulations. The

RFA requires an analysis if a final rule

will have ‘‘a significant economic

impact on a substantial number of small

entities.’’ The definitions of small

entities and guidance material for

making determinations required by the

RFA are contained in the Federal

Register (47 FR 32825, July 29, 1982).

Federal Aviation Administration (FAA)

order 2100.14A outlines the agency’s

procedures and criteria for

implementing the RFA.

With respect to the final rule, a ‘‘small

entity’’ is an operator of aircraft for hire

with nine or fewer aircraft. A

‘‘significant economic impact on a small

entity’’ is defined as an annualized net

compliance cost for operators of aircraft

for hire which in 1996 dollars is

$126,100 for scheduled operators whose

aircraft have more than 60 seats. It is

$70,490 for scheduled operators whose

fleets have aircraft with seating

capacities of 60 or fewer seats (other

scheduled operators) and $4,960 for

unscheduled operators. A substantial

number of small entities is defined as a

number that is 11 or more and which is

more than one-third of small operators

subject to the final rule.

The FAA estimates that the

annualized cost of the final rule is about

$4,708 per aircraft and that the

annualized cost savings to the operator

is about $2,142 per aircraft. Therefore,

the net annualized cost is about $2,566

per aircraft.

The FAA has initially determined that

if every operator were defined as

unscheduled, then operators with two

aircraft or more will incur a significant

impact.

The cost for an operator with two

aircraft is slightly over the threshold of

$4,960 by approximately three and a

half percent. However, in the regulatory

evaluation and the above regulatory
Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations 42373

flexibility analysis, the FAA has made

conservative assumptions that could

result in costs per aircraft being

overestimated. For example, the FAA

has assumed that none of the aircraft are

in partial compliance with any of the

equipment requirements of this

regulation. To the extent that some

operators have aircraft that are in partial

compliance, then costs per aircraft have

been overestimated and the FAA

believes that compliance costs per

aircraft are overestimated by more than

five percent. An example of this are the

weight penalty costs. The FAA assumed

that a battery and related hardware

would add 30 pounds to the weight of

the aircraft. A Gill 25 amp battery

weighing 22 pounds plus hardware

would be adequate and weighs about 25

pounds. Therefore, the difference in

weight (5 pounds × 15 gallons/pound ×

$2.32/gallon=$174) would result in

aircraft being under the threshold.

Consequently, operators with two or

fewer aircraft would not likely to be

significantly impacted. The FAA has

concluded that this is the case and,

therefore, the rule will not affect a

substantial number of small entities. In

addition, many operators that the FAA

considered as being potentially

impacted may choose not to carry

passengers under IFR. For these reasons,

the FAA has determined that a

substantial number of operators will not

be positively or negatively impacted in

a significant way.

International Trade Impact Statement

This final rule is not expected to have

any impact on trade opportunities for

U.S. firms doing business overseas or

foreign firms doing business in the

United States. The final rule will

primarily affect U.S. operators of aircraft

for hire that provide domestic service.

Unfunded Mandates Reform Act

Assessment

Title II of the Unfunded Mandates

Reform Act of 1995 (the Act), enacted as

Pub. L. 104–4 on March 22, 1995,

requires each Federal agency, to the

extent permitted by law, to prepare a

written assessment of the effects of any

Federal mandate in a proposed or final

agency rule that may result in the

expenditure by State, local, and tribal

governments, in the aggregate, or by the

private sector, of $100 million or more

(adjusted annually for inflation) in any

one year. Section 204(a) of the Act, 2

U.S.C. 1534(a), requires the Federal

agency to develop an effective process

to permit timely input by elected

officers (or their designees) of State,

local, and tribal governments on a

proposed ‘‘significant intergovernmental

mandate.’’ A ‘‘significant

intergovernmental mandate’’ under the

Act is any provision in a Federal agency

regulation that will impose an

enforceable duty upon State, local, and

tribal governments, in the aggregate, of

$100 million (adjusted annually for

inflation) in any one year. Section 203

of the Act, 2 U.S.C. 1533, which

supplements section 204(a), provides

that before establishing any regulatory

requirements that might significantly or

uniquely affect small governments, the

agency shall have developed a plan that,

among other things, provides for notice

to potentially affected small

governments, if any, and for a

meaningful and timely opportunity to

provide input in the development of

regulatory proposals.

This final rule does not meet the cost

thresholds described above.

Furthermore, this final rule will not

impose a significant cost on small

governments and will not uniquely

affect those small governments.

Therefore, the requirements of Title II of

the Unfunded Mandates Reform Act of

1995 do not apply.

Paperwork Reduction Act of 1995

The proposed recordkeeping

requirements for the engine trend

monitoring (new § 135.421(e)) and the

written maintenance instructions (new

§ 135.421(d)) are subject to OMB

approval, as required by the Paperwork

Reduction Act. Pending OMB clearance

on the paperwork requirements, SFAR

No. 81 is not effective until the FAA

publishes in the Federal Register a

notice specifying the effective date. An

information collection control number

will be assigned if and when OMB

approval is given; that number would be

listed in part 11, subpart F of Title 14.

Conclusion

For the reasons discussed in the

Preamble, and based on the findings in

the Regulatory Flexibility Assessment

and the International Trade Impact

Analysis, the FAA has determined that

this rule is not a ‘‘significant regulatory

action’’ under Executive Order 12866. In

addition, the FAA certifies that this

regulation does not have a significant

economic impact, positive or negative,

on a substantial number of small entities

under the criteria of the Regulatory

Flexibility Act of 1980. This amendment

is not considered significant under

Order DOT 2100.5, Policies and

Procedures for Simplification, Analysis,

and Review of Regulations. A regulatory

evaluation of the regulation is available

in the docket.

List of Subjects in 14 CFR Part 135

Air carriers, Air taxis, Air

transportation, Aircraft, Airmen,

Airworthiness, Aviation safety, Ondemand operations, Pilots, Rotorcraft,

Safety, Single-engine aircraft, Singleengine airplane.

For the reasons set out in the

preamble, 14 CFR part 135 is amended

as set forth below:

PART 135—OPERATING

REQUIREMENTS: COMMUTER AND

ON-DEMAND OPERATIONS

1. The authority citation for part 135

continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701–

44702, 44705, 44709, 44711–44713, 44715–

44717, 44722.

2. Special Federal Aviation

Regulation No. 81 is added to read as

follows:

SFAR No. 81—PASSENGER-CARRYING

SINGLE-ENGINE IFR OPERATIONS.

1. Purpose and Eligibility.

(a) This Special Federal Aviation

Regulation provides for the approval of

single-engine passenger-carrying operations

under instrument flight rules (IFR) during the

month prior to the effective date of the

Commercial Passenger-Carrying Operations

in Single-Engine Aircraft Under Instrument

Flight Rules rule.

(b) This SFAR terminates on May 3, 1998.

(c) Only those single-engine, passengercarrying operations meeting all the

applicable requirements of part 135 and

those requirements set forth in paragraph 2

of this SFAR may operate under IFR.

2. Contrary provisions of §§ 135.103 and

135.181 notwithstanding, a person may

conduct passenger-carrying operations under

IFR in single-engine aircraft if the following

conditions are met:

(a) The aircraft has two independent

electrical power generating sources each of

which is able to supply all probable

combinations of continuous inflight electrical

loads for required instruments and

equipment; or in addition to the primary

electrical power generating source, a standby

battery or an alternate source of electric

power that is capable of supplying 150% of

the electrical loads of all required

instruments and equipment necessary for

safe emergency operation of the aircraft for at

least one hour;

(b) The aircraft has two independent

sources of energy (with means of selecting

either), of which at least one is an enginedriven pump or generator, each of which is

able to drive all gyroscopic instruments and

installed so that failure of one instrument or

source does not interfere with the energy

supply to the remaining instruments or the

other energy source;

(c) The aircraft meets the autopilot

requirements of § 135.105 or has a second in

command;

(d) The certificate holder’s maintenance

inspection program incorporates either the

manufacturer’s recommended engine trend
42374 Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 / Rules and Regulations

monitoring program, which includes an oil

analysis, if appropriate, or an FAA approved

engine trend monitoring program that

includes an oil analysis at each 100 hour

interval or at the manufacturer’s suggested

interval, whichever is more frequent.

(e) The results of each test, observation,

and inspection required by the applicable

engine trend monitoring program are

recorded and maintained in the engine

maintenance records; and

(f) Written maintenance instructions

containing the methods, techniques, and

practices necessary to maintain the

equipment specified in paragraph 2 (a), (b),

and (c) are prepared.

3. Section 135.101 is revised to read

as follows:

§ 135.101 Second in command required

under IFR.

Except as provided in § 135.105, no

person may operate an aircraft carrying

passengers under IFR unless there is a

second in command in the aircraft.

§ 135.103 [Removed and reserved]

4. Section 135.103 is removed and

reserved.

5. Section 135.163 is amended by

revising paragraphs (f), (g), and (h) to

read as follows:

§ 135.163 Equipment requirements:

Aircraft carrying passengers under IFR.

* * * * *

(f) For a single-engine aircraft:

(1) Two independent electrical power

generating sources each of which is able

to supply all probable combinations of

continuous inflight electrical loads for

required instruments and equipment; or

(2) In addition to the primary

electrical power generating source, a

standby battery or an alternate source of

electric power that is capable of

supplying 150% of the electrical loads

of all required instruments and

equipment necessary for safe emergency

operation of the aircraft for at least one

hour;

(g) For multi-engine aircraft, at least

two generators or alternators each of

which is on a separate engine, of which

any combination of one-half of the total

number are rated sufficiently to supply

the electrical loads of all required

instruments and equipment necessary

for safe emergency operation of the

aircraft except that for multi-engine

helicopters, the two required generators

may be mounted on the main rotor drive

train; and

(h) Two independent sources of

energy (with means of selecting either),

of which at least one is an engine-driven

pump or generator, each of which is

able to drive all gyroscopic instruments

and installed so that failure of one

instrument or source does not interfere

with the energy supply to the remaining

instruments or the other energy source

unless, for single-engine aircraft in allcargo operations only, the rate-of-turn

indicator has a source of energy separate

from the bank and pitch and direction

indicators. For the purpose of this

paragraph, for multi-engine aircraft,

each engine-driven source of energy

must be on a different engine.

* * * * *

6. Section 135.181 is amended by

revising paragraphs (a)(1) and (c) to read

as follows:

§ 135.181 Performance requirements:

Aircraft operated over-the-top or in IFR

conditions.

(a) * * *

(1) Operate a single-engine aircraft

carrying passengers over-the-top; or

* * * * *

(c) Without regard to paragraph (a) of

this section, if the latest weather reports

or forecasts, or any combination of

them, indicate that the weather along

the planned route (including takeoff and

landing) allows flight under VFR under

the ceiling (if a ceiling exists) and that

the weather is forecast to remain so

until at least 1 hour after the estimated

time of arrival at the destination, a

person may operate an aircraft over-thetop.

* * * * *

§ 135.411 [Amended]

7. Section 135.411 is amended by

adding paragraph (c) to read as follows:

* * * * *

(c) Single engine aircraft used in

passenger-carrying IFR operations shall

also be maintained in accordance with

§ 135.421 (c), (d), and (e).

8. Section 135.421 is amended by

adding paragraph (c), (d), and (e) to read

as follows:

§ 135.421 Additional maintenance

requirements.

* * * * *

(c) For each single engine aircraft to

be used in passenger-carrying IFR

operations, each certificate holder must

incorporate into its maintenance

program either:

(1) the manufacturer’s recommended

engine trend monitoring program,

which includes an oil analysis, if

appropriate, or

(2) an FAA approved engine trend

monitoring program that includes an oil

analysis at each 100 hour interval or at

the manufacturer’s suggested interval,

whichever is more frequent.

(d) For single engine aircraft to be

used in passenger-carrying IFR

operations, written maintenance

instructions containing the methods,

techniques, and practices necessary to

maintain the equipment specified in

§§ 135.105, and 135.163 (f) and (h) are

required.

(e) No certificate holder may operate

a single engine aircraft under IFR,

carrying passengers, unless the

certificate holder records and maintains

in the engine maintenance records the

results of each test, observation, and

inspection required by the applicable

engine trend monitoring program

specified in (c) (1) and (c) (2) of this

section.

Issued in Washington, DC on July 31, 1997.

Barry L. Valentine,

Acting Administrator.

[FR Doc. 97–20641 Filed 8–1–97; 11:49 am]

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