[Federal Register Volume 61, Number 60 (Wednesday, March 27, 1996)]
[Rules and Regulations]
[Pages 13642-13644]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7429]




[[Page 13641]]

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Part VII





Department of Transportation





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Federal Aviation Administration



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14 CFR Part 23



Powerplant Instruments; Fuel Pressure Indication; Final Rule

  Federal Register / Vol. 61, No. 60 / Wednesday, March 27, 1996 / 
Rules and Regulations  

[[Page 13642]]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. 28011; Amendment No. 23-52]
RIN 2120-AF41


Powerplant Instruments; Fuel Pressure Indication

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This document amends the certification requirement for fuel 
pressure indicators on pump-fed engines of normal, utility, acrobatic, 
and commuter category airplanes to permit regulatory alternatives to 
fuel pressure indicators to warn pilots of fuel system problems. A fuel 
pressure indicator is not technically the only means available to the 
pilot of indicating a fuel system problem. The amendment allows 
airplanes to be certificated with a means that indicates fuel flow or 
that monitors the fuel system and warns the pilot of any fuel flow 
trend that could lead to engine failure. New technology incorporated as 
a means of compliance with the revised rule could improve engine 
operation and reduce airplane operating costs.

EFFECTIVE DATE: July 25, 1996.

FOR FURTHER INFORMATION CONTACT:
J. Lowell Foster, Aerospace Engineer, Standards Office, Small Airplane 
Directorate, Aircraft Certification Service, Federal Aviation 
Administration, 601 East 12th Street, Kansas City, Missouri 64106; 
telephone (816) 426-5688.

SUPPLEMENTARY INFORMATION: 

Background

Statement of the Problem

    The FAA proposed to amend Title 14 of the Code of Federal 
Regulations (CFR), Part 23, Sec. 23.1305(b)(4), which required a fuel 
pressure indicator for each pump-fed engine. The pressure indicator 
gives continuous fuel pressure readings to the pilot. This information 
provides an advance warning of engine failure only when a pilot notices 
the pressure reading has deviated from the norm and when the pilot can 
diagnose what those deviations mean in terms of potential engine 
failure. The change would allow the options of a fuel pressure 
indicator, a fuel flow indicator, or a means that continuously monitors 
the fuel system and warns the pilot of any fuel flow trend that could 
cause engine failure. A fuel flow indicator would give continuous fuel 
flow readings to the pilot. Fuel flow information presents the fuel 
system status to the pilot in a manner similar to the fuel pressure 
indicator, but it also allows the pilot to quickly assess the engine's 
performance during critical phases of flight, such as takeoff. A 
continuous fuel system monitoring device would alert the pilot to any 
fuel flow trend that could lead to engine failure.

History

    The Aircraft Owners and Pilots Association (AOPA) petitioned the 
FAA for new standards that would allow, on all pump-fed engines, a fuel 
flow system employing a differential pressure transducer to be accepted 
as a means of compliance equivalent to the current fuel pressure 
indicator requirements (55 FR 39299, September 26, 1990). The FAA 
requested that the Aviation Rulemaking Advisory Committee (ARAC) review 
the petition and recommend a course of action. In January 1992, the 
Fuel Pressure Indicators Working Group of the ARAC on General Aviation 
and Business Airplane Issues began a review of the AOPA's petition. As 
a result of the review, a Notice of Proposed Rulemaking (NPRM), Notice 
No. 94-37, was published on December 28, 1994 (59 FR 67114).

Discussion of Comments

General

    This amendment is based on the NPRM, Notice No. 94-37, published 
December 28, 1994 (59 FR 67114). Interested persons were invited to 
participate in the development of this final rule by submitting written 
data, views, or arguments to the regulatory docket on or before 
February 27, 1995. Four comments were received on the proposal, 
including a letter of support from the Air Line Pilots Association.
    The intent of the fuel pressure indicator requirement for pump-fed 
engines is to advise the pilot of a fuel pressure deficiency before 
total engine failure. The term ``indicator'' in Sec. 23.1305(b)(4) 
implies that the fuel pressure be constantly displayed.
    The FAA proposed a change to allow a fuel pressure indicator or a 
fuel flow indicator. The fuel flow indicator would constantly display 
information that the pilot could use to evaluate engine power, fuel 
mixture, and other engine performance factors in addition to fuel 
system status. It is technologically possible to have a microprocessor 
that monitors engine operation and triggers a warning if the fuel 
system operation does not match the other monitored engine trends; 
therefore, the FAA also proposed to change the rule to accept a means 
that monitors the fuel system and warns the pilot of any fuel flow 
trend that could lead to engine failure.
    Accordingly, the FAA proposed to adopt a performance standard, 
instead of a requirement for specific equipment. An applicant could 
show compliance with paragraph (b) of the proposal by using any design 
that monitors the fuel system and warns the pilot of any fuel flow 
trend that could lead to engine failure.

Discussion of Comments to Section 23.1305

    One commenter, a private individual, does not feel that 
Sec. 23.1305(b)(4) should be changed as proposed. The commenter 
believes that ``an accurate indication is necessary for the pilot to 
have a situation awareness of his operating environment.'' The FAA 
understands and agrees with the overall basis for the comment; however, 
the FAA does not agree with all of the commenter's arguments and will 
address them individually.
    First, the commenter believes the proposal implies that small 
airplane engines are ``antiquated'' using ``antiquated fuel flow 
means.'' The NPRM sections discussing the history of this rule focused 
on fuel pump reliability, radial engines, and diagnosing fuel pump 
failures, which were more frequent in the 1940's and 1950's than today. 
The FAA's intention in discussing the rule's history was to point out 
that the reliability of fuel pumps has improved since the 1940's. The 
FAA did not intend to imply that these engines were in some way 
``antiquated.'' In fact, as the commenter points out, the basic engines 
used on most small airplanes are derivatives of the engines designed in 
the 1940's. Civil Air Regulation 3 airplanes, which constitute over 85 
percent of the existing small airplanes flying today, have an excellent 
service history.
    The commenter also points out that ``continual reference to 
automobile monitoring systems is well taken, except that automobiles 
can have a problem and pull off to the side of the road.'' 
Additionally, ``[a]utomobiles may have indicator lights and warnings as 
to the state of fule consumption, but they also have a fuel quantity 
gauge so the driver can monitor the system in use to also determine an 
accurate fuel flow.'' The FAA used the reference to automobile 
technology to make the point that sophisticated engine monitoring is 
inexpensive enough to be mass produced for automobiles. Complex fuel

[[Page 13643]]
monitoring systems are available in business jets and recently-
certificated jet transport aircraft. This technology may soon be 
affordable to small airplane owners and manufacturers, and the FAA does 
not want to impede progress with rules offering no alternatives.
    The commenter believes that the proposal would allow ``idiot 
lights.'' On the contrary, the FAA stated in the NPRM, ``A light that 
comes on at the same time that the engine quits is useless. A warning 
light system that would comply with this proposal would be 
sophisticated enough to read transients and trends, and would give a 
useful warning to the pilot.'' Also, the rule as proposed would require 
that any warning light system continuously monitor the fuel system and 
warn the pilot of any fuel flow trend that could lead to an engine 
failure.
    Transport Canada questions the ability to show compliance with the 
requirement in Sec. 23,1549 to identify maximum and, if applicable, 
minimum safe operating limits as well as the normal operating range of 
the instrument. This commenter points out that the typical fuel flow 
meter is a digital type, and it would be difficult for the applicant to 
provide equivalent markings, Engine manufacturers provide the 
information required by Sec. 23.1549, which is then usually transcribed 
to the installed fuel pressure gauge. It appears that this information 
would not be presented through the use of typical digital fuel flow 
meters. The commenter offers the following suggestion: ``FAR 23.1549 
was written with a traditional dial instrument in mind where the engine 
limitations could be easily displayed on the face of the unit and 
monitored by the crew. To allow flow meters or other fuel system 
monitors to satisfy the requirements of Sec. 23.1549 where such a gauge 
no longer exists, compliance could be shown by (1) different colors to 
indicate changing trends in system performance (e.g., amber color for a 
low pressure/flow condition, red for impending engine failure), or (2) 
placarding, if appropriate, to indicate the normal and abnormal 
operating ranges.''
    The FAA agrees with the commenter's suggestions as an acceptable 
means of compliance with Sec. 23.1549. Suggested items (1) and (2) 
above offer the pilot a means to determine fuel flow limitations, which 
may be needed if a fuel flow meter is installed.
    A commenter from Australia supports the proposal; however, the 
commenter feels that the proposed text would require a monitoring 
system that provides a warning of any trend that could lead to engine 
failure, which is an extremely difficult compliance requirement. The 
commenter further states: ``The historic requirement, and the NRPM 
preamble, clearly addresses fuel pressure (as an indication of the 
availability of fuel flow) or fuel flow only. Such wording may stifle 
the development of monitoring instrumentation for small airplanes.'' 
The commenter suggests that, for clarification, the proposed text for 
Sec. 23.1305(b)(4)(ii), be amended to read as follows: ``That 
continuously monitors the fuel system and warns the pilot of any fuel 
flow trend that could lead to engine failure.''
    The FAA agrees with the commenter that the proposed wording may be 
too broad, making compliance difficult or the system unnecessarily 
complex. The FAA encourages ``smart'' systems; however, the intent of 
the proposal was to warn the pilot of any fuel flow trend and, for that 
reason, the final rule and the preamble adopt the commenter's language.
    Section 23.1305 is adopted with the change in paragraph (b)(4)(ii) 
to add the words ``fuel flow'' before the word ``trend.''

International Compatibility

    The agency has reviewed corresponding International Civil Aviation 
Organization international standards and recommended practices and 
Joint Aviation Authorities requirements for compatibility. The FAA has 
determined that this final rule, if adopted, would not present any 
differences.

Paperwork Reduction Act

    In accordance with the Paperwork Reduction Act of 1990 (44 U.S.C. 
3501 et seq.), there are no reporting or recordkeeping requirements 
associated with this rule.

Regulatory Evaluation Summary

Economic Evaluation, Regulatory Flexibility Determination, and Trade 
Impact Assessment

    Proposed changes to federal regulations must undergo several 
economic analyses. First, Executive Order 12866 directs Federal 
agencies to promulgate new regulations or modify existing regulations 
only if the potential benefits to society outweigh the potential costs. 
Second, the Regulatory Flexibility Act of 1980 requires agencies to 
analyze the economic impact of regulatory changes on small entities. 
Finally, the Office of Management and Budget directs agencies to assess 
the effects of regulatory changes on international trade. In conducting 
these analyses, the FAA has determined that this rule: (1) will 
generate benefits exceeding its costs and is not significant as defined 
in Executive Order 12866; (2) is not significant as defined in DOT's 
Policies and Procedures; (3) will not have a significant economic 
impact on small entities; and (4) will not affect international trade. 
These analyses, available in the docket, are summarized below.

Economic Evaluation

    The rule adopts a performance standard instead of requiring 
specific equipment. In this way, manufacturers can develop any design 
that monitors the fuel system and warns the pilot of any fuel flow 
trend that could lead to engine failure. The objective of imposing a 
performance standard could be met in this case by any means that 
``continuously indicates to the pilot fuel pressure or fuel flow, or 
that continuously monitors the fuel system and warns the pilot of any 
fuel flow trend that could lead to engine failure.'' This will maintain 
the level of safety intended by the original requirement, without 
imposing any additional costs. For example, a warning light system 
could possibly alert the pilot sooner than if the pilot relied on an 
instrument panel scan to notice a trend in the fuel pressure indication 
alone (as is currently the case).
    A fuel flow indicator offers additional benefits compared to a fuel 
pressure indicator in that it enables the pilot to monitor the engine's 
fuel consumption and compare it to fuel consumption listed in the 
airplane flight manual. Consequently, engine operation could be 
improved, resulting in reduced fuel consumption and operating costs. In 
addition, continual fuel flow readings are useful during critical 
phases of flight, such as takeoff and climb. Thus, flight safety could 
be enhanced. The other alternative, a means to continuously monitor the 
fuel system, will also enhance safety by alerting the pilot to any fuel 
flow trend that could lead to engine failure.
    Since the rule will permit but not require alternative means of 
warning pilots of fuel system problems, it is inherently cost-
beneficial. To the extent that it encourages the future development and 
utilization of comprehensive engine control, monitoring, and diagnostic 
systems, it will generate benefits in the form of enhanced safety, 
improved fuel efficiency, power output, and engine life.

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Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (RFA) was enacted by 
Congress to ensure that small entities are not unnecessarily and 
disproportionately burdened by government regulations. The RFA requires 
a Regulatory Flexibility Analysis if a proposed or final rule would 
have a significant economic impact, either detrimental or beneficial, 
on a substantial number of small entities. FAA Order 2100.14A, 
Regulatory Flexibility Criteria and Guidance, prescribes standards for 
complying with RFA requirements in FAA rulemaking actions. The Order 
defines ``small entities'' in terms of size, ``significant economic 
impact'' in terms of annualized costs, and ``substantial number'' as a 
number which is not less than eleven and which is more than one-third 
of the small entities subject to a proposed of final rule.
    The rule will affect manufacturers of future part 23 airplanes. For 
manufacturers, Order 2100.14A defines a small entity as one with 75 or 
fewer employees and a significant economic impact as annualized costs 
of $19,000 or more. The FAA has determined that the rule will not have 
a significant economic impact on a substantial number of small 
manufacturers since the annualized certification costs of the rule are 
less than $19,000.

International Trade Impact Assessment

    The rule will not constitute a barrier to international trade, 
including the export of U.S. airplanes and airplane parts to foreign 
markets or the import of foreign airplanes and airplane parts in the 
United States.

Federalism Implications

    The regulations 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 regulation will not have 
sufficient federalism implications to warrant the preparation of a 
Federalism Assessment.

Conclusion

    The FAA amends the airworthiness standards to allow airplane 
manufacturers to utilize new technology for fuel system monitoring to 
improve the operation and economy of part 23 airplanes powered by pump-
fed engines. The current rule requires a fuel pressure indication; 
thus, it limits the means of compliance. The advances in engines 
monitoring systems and electronics offer technology that should be 
utilized by the aviation community. By broadening this airworthiness 
standard, fuel flow indicators or new fuel system monitors may provide 
better information to the pilot.
    For the reasons discussed in the preamble, and based on the 
findings in the Regulatory Flexibility Determination and the 
International Trade Impact Analysis, the FAA has determined that this 
regulation is not significant under Executive Order 12866. In addition, 
the FAA certifies that this regulation will not have a significant 
economic impact, positive or negative, on a substantial number of small 
entities under the criteria of the Regulatory Flexibility Act. The 
regulation is not considered significant under DOT Regulatory Policies 
and Procedures (44 FR 11034; February 26, 1979). A regulatory 
evaluation of the regulation, including a Regulatory Flexibility 
Determination and Trade Impact Analysis, has been placed in the docket. 
A copy may be obtained by contacting the person identified under FOR 
FURTHER INFORMATION CONTACT.

List of Subjects in 14 CFR Part 23

    Aircraft, Aviation safety, Signs and symbols.

The Amendment

    In consideration of the foregoing, the Federal Aviation 
Administration amends 14 CFR part 23 as follows:

PART 23--AIRWORTHINESS STANDARDS; NORMAL, UTILITY, ACROBATIC, AND 
COMMUTER CATEGORY AIRPLANES

    1. The authority citation for part 23 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

    2. Section 23.1305 is amended by revising paragraph (b)(4) to read 
as follows:


Sec. 23.1305  Powerplant instruments.

* * * * *
    (b) * * *
    (4) For each pump-fed engine, a means:
    (i) That continuously indicates, to the pilot, the fuel pressure or 
fuel flow; or
    (ii) That continuously monitors the fuel system and warns the pilot 
of any fuel flow trend that could lead to engine failure.
* * * * *
    Issued in Washington, D.C. on March 21, 1996.
David R. Hinson,
Administrator.
[FR Doc. 96-7429 Filed 3-26-96; 8:45 am]
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