[Federal Register Volume 74, Number 233 (Monday, December 7, 2009)]
[Rules and Regulations]
[Pages 63968-63970]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-29053]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE301; Special Conditions No. 23-241-SC]


Special Conditions: Embraer S.A., Model EMB-505; High Fuel 
Temperature

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Embraer S.A., 
Model EMB-505 airplane. This airplane will have a novel or unusual 
design feature(s) associated with high fuel temperature. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for this design feature. These special conditions contain the 
additional safety standards that the Administrator considers necessary 
to establish a level of safety equivalent to that established by the 
existing airworthiness standards.

DATES: The effective date of these special conditions is December 1, 
2009. We must receive your comments by January 6, 2010.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Regional Counsel, ACE-7, Attention: Rules 
Docket Clerk, Docket No. CE301, Room 506, 901 Locust, Kansas City, 
Missouri 64106. Mark comments: Docket No. CE301. You may inspect 
comments in the Rules Docket weekdays, except Federal holidays, between 
7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Peter L. Rouse, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust, Kansas City, Missouri, 816-329-4135, 
fax 816-329-4090.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected aircraft. In addition, the 
substance of these special conditions has been subject to the public 
comment process in several prior instances with no substantive comments 
received. The FAA therefore finds that good cause exists for making 
these special conditions effective upon issuance.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written data, views, or arguments as they may desire. The most 
helpful comments reference a specific portion of the special 
conditions, explain the reason for any recommended change, and include 
supporting data. We ask that you send us two copies of written 
comments.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
concerning these special conditions. You can inspect the docket before 
and after the comment closing date. If you wish to review the docket in 
person, go to the address in the ADDRESSES section of this preamble 
between 7:30 a.m. and 4 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.
    If you want the FAA to acknowledge receipt of the comments on this 
proposal, include with your comments a pre-addressed, stamped postcard 
on which the docket number appears. We will stamp the date on the 
postcard and mail it back to you.

Discussion

Background

    On October 9, 2006, Embraer S.A. applied for a type certificate for 
their new Model EMB-505. The Model EMB-505 is a commuter category, low-
winged monoplane with ``T'' tailed vertical and horizontal stabilizers, 
retractable tricycle type landing gear and twin turbofan engines 
mounted on the aircraft fuselage. Its design characteristics include a 
predominance

[[Page 63969]]

of metallic construction. The maximum takeoff weight is 17,967 pounds, 
the VMO/MMO is 320 KCAS/M 0.78 and maximum 
altitude is 45,000 feet.
    Fuel temperatures on the Embraer EMB 505 are higher than envisioned 
by 14 CFR part 23. The rule governing fuel system hot weather operation 
is 14 CFR part 23, Sec.  23.961, and the rule requires the following:

    Each fuel system must be free from vapor lock when using fuel at 
its critical temperature, with respect to vapor formation, when 
operating the airplane in all critical operating and environmental 
conditions for which approval is requested. For turbine fuel, the 
initial temperature must be 110 [deg]F, -0 [deg], +5 [deg] or the 
maximum outside air temperature for which approval is requested, 
whichever is more critical.

    During other airplane certification projects, the fuel system 
temperatures associated with the recently designed turbofan engines 
were much higher than those previously encountered on previous airplane 
certification projects. The engine oil/fuel heat fuel system includes 
an exchanger that cools the oil and heats the fuel. Consequently, the 
motive flow fuel that is returned to the airplane from the engine is 
hot and heats the airplane wing fuel and tank. As a result, on the 
PW535E, the engine inlet maximum fuel temperature was determined to 
reach up to 196.7 [deg]F (91.5 [deg]C) during design development 
testing.
    Initial concerns regarding the safe operation of the airplane with 
fuel temperatures significantly greater than 110 [deg]F are identified 
as:
     Fuel degradation with resultant byproducts at high 
temperatures.
     Operation with the higher vapor liquid ratios.
     Fuel system component qualification at the higher 
temperatures.
     Solubility of water in fuel.
     Microbial growth.
     Fuel tank material/surrounding structure compatibility 
with the elevated temperatures.
     Service and maintenance personnel susceptibility to burns.
    An initial review of FAA experience regarding airplane fuel 
temperatures identifies that for large part 25 aircraft, fuel 
temperature upper limits are characterized by Sec.  25.961 values, 
i.e., 110-120 [deg]F. Operationally, the buildup of vapor pockets 
within fuel lines has been an issue from this perspective for large 
transport category airplanes. A summary of the maximum engine inlet 
fuel temperatures for engines used in part 23 and part 25 business jet 
airplanes that are FAA certified follows:

------------------------------------------------------------------------
                                          Sea level maximum inlet fuel
             Engine model                          temperature
------------------------------------------------------------------------
PWC615F...............................  126 F (52 C) draft IM.
PWC615F...............................  172 F (78 C) Transport Canada.
PWC615F...............................  190 F (88 C).
530A, 535A............................  135 F (57 C).
545A..................................  135 F (57 C).
305A..................................  135 F (57 C).
308...................................  135 F (57 C).
JT15D-4, -4B, -4D.....................  135 F (57 C).
FJ44-3A...............................  200 F (93 C).
FJ44-2A...............................  135 F (57 C).
FJ44-1B...............................  135 F (57 C).
TFE731-2/-3...........................  135 F (57 C).
TFE731-20.............................  135 F (57 C).
------------------------------------------------------------------------

    CAR part 3, as amended to May 15, 1956, defined the maximum 
anticipated summer air temperatures in Sec.  3.583; ``The maximum 
anticipated summer air temperature shall be considered to be 100 [deg]F 
at sea level and to decrease from this value at the rate of 3.6 [deg]F 
per thousand feet above sea level.'' Concurrently, Sec.  3.438 required 
that ``* * * fuel system features conducive to vapor formation shall be 
demonstrated to be free from vapor lock when using fuel at a 
temperature of 110 [deg]F under critical operating conditions.'' 
Building from CAR part 3, 14 CFR part 23 envisioned maximum fuel 
temperatures at or near 110 [deg]F as set forth in 14 CFR part 23, 
Sec.  23.961. The turbine fuel temperature requirement for hot weather 
operation is 110 -0, +5 [deg]F, or the maximum outside air temperature 
for which approval is requested, whichever is more critical. Engine 
heat rejection such that the airplane fuel temperature is characterized 
by engine heat rejection rather than ambient air temperature is a new 
and novel design that was not envisioned by 14 CFR part 23.
    14 CFR part 23 certification experience to date has shown that hot 
weather certification testing with 110 [deg]F fuel temperatures is 
adequate for fuel system operations for fuel tank fuel temperatures 
characterized by ambient air temperatures including cooling as a result 
of the atmospheric temperature lapse rate. Heating that increases the 
airplane fuel system operational temperatures introduces several fuel 
system concerns. Each must be shown to be acceptable. Compliance by 
design (i.e., lack of ability to shutoff the engine motive flow) may be 
utilized although associated type certificate data sheet information 
may also be necessary to assure future system changes are compliant.
    A special condition for the higher fuel system temperatures of the 
Embraer EMB-505 airplane was proposed. The special condition requires 
the compliance to 14 CFR part 23, Sec.  23.961, fuel system hot weather 
operation test temperature to be commensurate with the highest fuel 
temperature expected at the maximum outside air temperature for which 
approval is requested.

Type Certification Basis

    Under the provisions of 14 CFR part 21, Sec.  21.17, Embraer S.A. 
must show that the Model EMB-505 meets the applicable provisions of 14 
CFR part 23, as amended by Amendments 23-1 through 23-55, thereto.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 23) do not contain adequate or 
appropriate safety standards for the Model EMB-505 because of a novel 
or unusual design feature, special conditions are prescribed under 
Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model EMB-505 must comply with the fuel vent and 
exhaust emission requirements of 14 CFR part 34 and the noise 
certification requirements of 14 CFR part 36, and the FAA must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as appropriate, as defined in 
Sec.  11.19, under Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17(a).
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model.

Novel or Unusual Design Features

    The Model EMB-505 will incorporate the following novel or unusual 
design features:
    High Fuel Temperatures.

Applicability

    As discussed above, these special conditions are applicable to the 
Model EMB-505. Should Embraer S.A. apply later for a change to the type 
certificate to include another model incorporating the same novel or 
unusual design feature, the special conditions would apply to that 
model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one model, Model EMB-505, of airplanes. It is not a rule of general 
applicability, and it affects only the applicant who applied

[[Page 63970]]

to the FAA for approval of these features on the airplane.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, because a delay would 
significantly affect the certification of the airplane, which is 
imminent, the FAA has determined that prior public notice and comment 
are unnecessary and impracticable, and good cause exists for adopting 
these special conditions upon issuance. The FAA is requesting comments 
to allow interested persons to submit views that may not have been 
submitted in response to the prior opportunities for comment described 
above.

List of Subjects in 14 CFR Part 23

    Aircraft, Aviation safety, Signs and symbols.

Citation

0
The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and 
21.17; and 14 CFR 11.38 and 11.19.

The Special Conditions

0
Accordingly, the Federal Aviation Administration (FAA) issues the 
following special conditions as part of the type certification basis 
for the Embraer S.A. Model EMB-505 airplanes.
    1. SC Sec.  23.961:
    Instead of compliance with Sec.  23.961, the following apply:
    Each fuel system must be free from vapor lock when using fuel at 
its critical temperature, with respect to vapor formation, when 
operating the airplane in all critical operating and environmental 
conditions for which approval is requested. For turbine fuel, the 
initial temperature must be the highest fuel temperature expected at 
the maximum outside air temperature for which approval is requested.

    Issued in Kansas City, Missouri, on December 1, 2009.
William J. Timberlake,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-29053 Filed 12-4-09; 8:45 am]
BILLING CODE 4910-13-P