[Federal Register: November 6, 2008 (Volume 73, Number 216)]
[Rules and Regulations]
[Page 65968-65971]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr06no08-3]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 29
[Docket No. SW022; Special Conditions No. 29-022-SC]
Special Conditions: Eurocopter France (ECF) Model EC225LP
Helicopter, Installation of a Search and Rescue (SAR) Automatic Flight
Control System (AFCS)
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 ECF Model EC225LP
helicopter. This helicopter will have novel or unusual design features
associated with installing an optional SAR AFCS. The applicable
airworthiness standards do not contain adequate or appropriate safety
requirements for this design feature. These special conditions contain
the additional safety standards the Administrator considers necessary
to show a level of safety equivalent to that established by the
existing airworthiness standards.
DATES: The effective date of these special conditions is October 30,
2008. We must receive your comments by December 22, 2008.
ADDRESSES: You must mail or deliver two copies of your comments to:
Federal Aviation Administration, Rotorcraft Directorate, Attn: Rules
Docket (ASW-111), Docket No. SW022, 2601 Meacham Blvd., Fort Worth,
Texas 76137. You must mark your comments: Docket No. SW022. You may
inspect comments in the Rules Docket weekdays, except Federal holidays,
between 8:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Jeff Trang, FAA, Rotorcraft
Directorate, ASW-111, Aircraft Certification Service, 2601 Meacham
Blvd., Fort Worth, Texas 76137; telephone (817) 222-5135; facsimile
(817) 222-5961.
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 design
approval and thus delivery of the affected aircraft. The FAA therefore
finds that good cause exists for making these special conditions
effective on issuance.
Comments Invited
We invite interested people to take part in this rulemaking by
sending written comments, data, or views. 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
about 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 document
between 8:30 a.m. and 4 p.m., Monday through Friday, except Federal
holidays.
We will consider all comments we receive by the closing date for
comments. We will consider comments filed late if it is possible to do
so without incurring additional expense or delay. We may change these
special conditions based on the comments we receive.
If you want us to let you know we received your comments on these
special conditions, send us a preaddressed, stamped postcard on which
the docket number appears. We will stamp the date on the postcard and
mail it back to you.
[[Page 65969]]
Background and Discussion
On March 27, 2006, ECF applied for a change to Type Certificate
(TC) No. H4EU to install an optional SAR AFCS in the Model EC225LP
helicopter. The Model EC225LP is a transport category helicopter
certified to Category A requirements when configured for more than nine
passengers and Category A or B requirements when configured for nine or
less passengers. This helicopter is also certified for instrument
flight under the requirements of Appendix B of 14 CFR part 29,
Amendment 29-47.
The use of dedicated AFCS upper modes, in which a fully coupled
autopilot provides operational SAR profiles, is needed for SAR
operations conducted over water in offshore areas clear of
obstructions. The SAR modes enable the helicopter to fly fully coupled
maneuvers, to include predefined search patterns during cruise flight,
and to transition from cruise flight to a stabilized hover and
departure (transition from hover to cruise flight). The SAR AFCS also
includes an auxiliary crew control that allows another crewmember (such
as a hoist operator) to have limited authority to control the
helicopter's longitudinal and lateral position during hover operations.
Flight operations conducted over water at night may have an
extremely limited visual horizon with little visual reference to the
surface even when conducted under Visual Meteorological Conditions
(VMC). Consequently, the certification requirements for SAR modes are
considered equivalent to operating under Instrument Meteorological
Conditions (IMC). While Appendix B to 14 CFR part 29 prescribes
airworthiness criteria for instrument flight, it does not consider
operations below instrument flight minimum speed (VMINI),
whereas the SAR modes allow for coupled operations at low speed, all-
azimuth flight to zero airspeed (hover).
Since SAR operations have traditionally been a public use mission,
the use of SAR modes in civil operations requires special airworthiness
standards (special conditions) to ensure that a level of safety
consistent with Category A and Instrument Flight Rule (IFR)
certification is maintained. In this regard, 14 CFR part 29 lacks
adequate airworthiness standards for AFCS SAR mode certification to
include flight characteristics, performance, and installed equipment
and systems.
Type Certification Basis
Under 14 CFR 21.101, ECF must show the EC225LP, as changed,
continues to meet the applicable provisions of the rules incorporated
by reference in TC No. H4EU or the applicable regulations in effect on
the date of application for the change. The regulations incorporated by
reference in the TC are commonly referred to as the ``original type
certification basis.'' The regulations incorporated by reference in
H4EU are as follows:
a. 14 CFR 21.29.
b. 14 CFR part 29 Amendments 29-1 to 29-25; plus Sec. 29.785
through Amendment 29-28; plus Sec. Sec. 29.963, 29.967, 29.973, 29.975
through Amendment 29-34; plus Sec. Sec. 29.25, 29.865 through
Amendment 29-42; plus Sec. Sec. 29.1, 29.2, 29.49, 29.51, 29.53,
29.55, 29.59, 29.60, 29.61, 29.62, 29.64, 29.65, 29.67, 29.73, 29.75,
29.77, 29.79, 29.81, 29.83, 29.85, 29.87, 29.307, 29.337, 29.351,
29.361, 29.391, 29.395, 29.397, 29.401, 29.403, 29.413, 29.427, 29.501,
29.519, 29.547, 29.549, 29.561(c), 29.561(d), 29.563, 29.602, 29.610,
29.613, 29.621, 29.625, 29.629, 29.631, 29.663, 29.674, 29.727, 29.755,
29.775, 29.783, 29.787, 29.803, 29.805, 29.807, 29.809, 29.811, 29.855,
29.861, 29.901, 29.903, 29.908, 29.917, 29.923, 29.927, 29.954, 29.961,
29.965, 29.969, 29.971, 29.991, 29.997, 29.999, 29.1001, 29.1011,
29.1019, 29.1027, 29.1041, 29.1043, 29.1045, 29.1047, 29.1093, 29.1125,
29.1141, 29.1143, 29.1163, 29.1181, 29.1189, 29.1193, 29.1305, 29.1309,
29.1323, 29.1329, 29.1337, 29.1351, 29.1359, 29.1415, 29.1521, 29.1549,
29.1557, 29.1587, A29, B29, C29, D29 through Amendment 29-47; plus
29.1317 through Amendment 29-49.
c. 14 CFR part 36 Amendment 21 (ICAO Annex 16, Volume 1, Chapter
8).
d. Equivalent Safety Findings:
(1) TC2899RD-R-F-01; Sec. 29.1303(j), Vne aural
warning.
(2) TC2899RD-R-F-02; Sec. 29.1545(b)(4), Airspeed indicators
markings.
(3) TC2899RD-R-F-03; Sec. 29.1549(b), Powerplant instruments
markings.
(4) TC2899RD-R-F-05; Sec. 29.173, 175, Static Longitudinal
Stability.
(5) TC2899RD-R-F-06; 14 CFR part 29, Appendix B, paragraph IV; IFR
Static Longitudinal Stability--Airspeed stability.
(6) TC2899RD-R-A-01; Sec. 29.807(d)(2), Ditching emergency exits
for passengers.
(7) TC2899RD-R-P-01; Sec. 29.923(a)(2), Rotor drive system and
control mechanism tests.
In addition to the applicable airworthiness standards and special
conditions, the ECF Model EC225LP 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.
Regulatory Basis for Special Conditions
If the Administrator finds the applicable airworthiness standards
(i.e., 14 CFR part 29) do not contain adequate or appropriate safety
requirements for the ECF Model EC225LP helicopter because of a novel or
unusual design feature, special conditions are prescribed under 14 CFR
21.16.
The FAA issues special conditions, as defined in Sec. 11.19, under
Sec. 11.38, and they become part of the type certification basis under
Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should the TC for that model be amended later to
include any other model that incorporates the same novel or unusual
design feature, or should any other model already included on the same
TC be modified to incorporate the same novel or unusual design feature,
these special conditions would also apply to the other model.
Novel or Unusual Design Features
The ECF Model EC225LP helicopter will incorporate the following
novel or unusual design features:
The SAR system is composed of a navigation computer with SAR modes,
an AFCS that provides coupled SAR functions, hoist operator control, a
hover speed reference system, and two radio altimeters. The AFCS
coupled SAR functions include:
a. Hover hold at selected height above the surface.
b. Ground speed hold.
c. Transition down and hover to a waypoint under guidance from the
navigation computer.
d. SAR pattern, transition down, and hover near a target over which
the helicopter has flown.
e. Transition up, climb, and capture a cruise height.
f. Capture and track SAR search patterns generated by the
navigation computer.
g. Monitor the preselected hover height with automatic increase in
collective if the aircraft height drops below the safety height.
These SAR modes are intended to be used over large bodies of water
in areas clear of obstructions. Further, use of the modes that
transition down from cruise to hover will include operation at
airspeeds below VMINI.
The SAR system only entails navigation, flight control, and coupled
AFCS operation of the helicopter. The
[[Page 65970]]
system does not include the additional equipment that may be required
for over water flight or external loads to meet other operational
requirements.
Applicability
These special conditions apply to the ECF Model EC225LP
helicopters. Should ECF apply at a later date for a change to the TC to
include another model incorporating the same novel or unusual design
feature, these special conditions would apply to that model as well
under the provisions of Sec. 21.101(d).
Conclusion
This action affects only certain novel or unusual design features
on one model of helicopter. It is not a rule of general applicability.
Normally, in adopting special conditions, we provide notice and an
opportunity for comment before issuing the final special conditions.
However, because the delivery date of the ECF Model EC225LP helicopter
is imminent, we find that it is impracticable to provide prior notice
because a delay would be contrary to the public interest. Therefore,
good cause exists to make these special conditions effective upon
issuance.
List of Subjects in 14 CFR Part 29
Aircraft, Aviation safety.
0
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.
The Special Conditions
0
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Eurocopter France EC225LP model
helicopters when the optional Search and Rescue (SAR) Automatic Flight
Control System (AFCS) is installed:
In addition to the part 29 certification requirements for Category
A and helicopter instrument flight (Appendix B), the following
additional requirements must be met for certification of the SAR AFCS:
(a) SAR Flight Modes. The coupled SAR flight modes must provide:
(1) Safe and controlled flight in three axes (lateral and
longitudinal position/speed and height/vertical speed) at all airspeeds
from instrument flight minimum speed (VMINI) to a hover.
(2) Automatic transition to the helicopter instrument flight
(Appendix B) envelope.
(3) A Go-Around mode that safely disengages any other coupled mode
in case of an aborted approach to a hover or SAR system failure.
(4) A means to prevent unintended flight below a safe minimum
height.
(b) SAR Mode System Architecture. To support the integrity of the
SAR modes, the following system architecture is required:
(1) A system for limiting the engine power demanded by the AFCS
when any of the automatic piloting modes are engaged, so FADEC power
limitations, such as torque and temperature, are not exceeded.
(2) A system providing the aircraft height above the surface and
final pilot-selected height at a location on the instrument panel in a
position acceptable to the FAA that will make it plainly visible to and
usable by any pilot at his station.
(3) A system providing the pilot-selected heading at a location on
the instrument panel in a position acceptable to the FAA that will make
it plainly visible to and usable by any pilot at his station.
(4) A system providing to any pilot the pilot-selected longitudinal
and lateral ground speeds used by the AFCS in the flight envelope where
airspeed indications become unreliable.
(5) A system providing wind speed and wind direction when automatic
piloting modes are engaged or transitioning from one mode to another.
(6) A system that monitors for flight guidance deviations and
failures, coupled with an appropriate and unmistakable alerting
function for the flight crew, unless it is shown that a deviation or
failure does not create a hazard.
(7) An alerting system that provides unmistakable visual or aural
alerts, or both, to the flight crew under any of the following
conditions:
(i) When the stored or pilot-selected minimum safety height is
reached.
(ii) When a SAR mode system malfunction occurs.
For normal transitions from one SAR mode to another, a single
visual or aural alert may suffice. For a SAR mode malfunction or a mode
having a time-critical component, the crew alerting system must
activate early enough to allow the crew to take timely and appropriate
action. The alerting means must be designed to alert the crew in order
to minimize crew errors that could create an additional hazard.
(8) The SAR system hoist operator control is considered a flight
control and must comply with the following:
(i) The hoist operator control must be designed and located to
provide for convenient operation and to prevent confusion and
inadvertent operation.
(ii) The helicopter must be safely controllable by the hoist
operator control throughout the range of that control.
(iii) The hoist operator control may not interfere with the safe
operation of the helicopter. Pilot and copilot flight controls must be
able to smoothly override the control authority of the hoist operator
control, without exceptional piloting skill, alertness, or strength,
and without the danger of exceeding any other limitation because of the
override.
(9) The reliability of the AFCS must be related to the effects of
its failure. The occurrence of any failure condition that would prevent
continued safe flight and landing must be extremely improbable. For any
failure condition of the AFCS which is not shown to be extremely
improbable:
(i) The helicopter must be safely controllable and capable of
continued safe flight without exceptional piloting skill, alertness, or
strength. Additional unrelated probable failures affecting the control
system must be evaluated.
(ii) The AFCS must be designed so that it cannot create a hazardous
deviation in the flight path or produce hazardous loads on the
helicopter during normal operation or in the event of a malfunction or
failure, assuming corrective action begins within an appropriate period
of time. Where multiple systems are installed, subsequent malfunction
conditions must be evaluated in sequence unless their occurrence is
shown to be improbable.
(10) A functional hazard assessment (FHA) and a system safety
assessment must be prepared and consider the catastrophic failure
conditions associated with SAR operations. For SAR catastrophic failure
conditions, changes may be required to the following:
(i) System architecture.
(ii) Software and complex electronic hardware design assurance
levels.
(iii) HIRF test levels.
(iv) Instructions for continued airworthiness.
The assessments must consider all the systems required for SAR
operations to include the AFCS, all associated AFCS sensors (e.g.,
radio altimeter), and primary flight displays. Electrical and
electronic systems with SAR catastrophic failure conditions (e.g.,
AFCS) must comply with the Sec. 29.1317(a)(4) High Intensity Radiated
Field (HIRF) requirements.
(c) SAR Mode Performance Requirements. (1) The SAR modes must be
demonstrated in the requested flight
[[Page 65971]]
envelope for the following minimum sea-state and wind conditions:
(i) Sea State: Wave height of 2.5 meters (8.2 feet), considering
both short and long swells.
(ii) Wind: 25 knots headwind; 17 knots for all other azimuths.
(2) The selected hover height and hover velocity must be captured
(to include the transition from one captured mode to another captured
mode) accurately and smoothly and not exhibit any significant overshoot
or oscillation.
(3) For any single failure or any combination of failures of the
AFCS that is not shown to be extremely improbable, the Minimum Use
Height (MUH) must result in a loss of height that is no greater than
half of the MUH with a minimum margin of 15 feet above the surface.
(4) The SAR mode system must be usable up to the maximum certified
gross weight of the aircraft or to the lower of the following weights:
(i) Maximum emergency flotation weight.
(ii) Maximum hover Out-of-Ground Effect (OGE) weight.
(iii) Maximum demonstrated weight.
(d) Flight Characteristics. (1) The basic aircraft must meet all
the part 29 airworthiness criteria for helicopter instrument flight
(Appendix B).
(2) For SAR mode coupled flight below VMINI, at the
maximum demonstrated winds, the helicopter must be able to maintain any
required flight condition and make a smooth transition from any flight
condition to any other flight condition without requiring exceptional
piloting skill, alertness, or strength, and without danger of exceeding
the limit load factor. This requirement also includes aircraft control
through the hoist operator's control.
(3) For SAR modes at airspeeds below VMINI, the
following requirements of Appendix B to part 29 must be met and will be
used as an extension to the IFR certification envelope of the basic
aircraft:
(i) Static Longitudinal Stability: The requirements of paragraph IV
of Appendix B are not applicable.
(ii) Static Lateral-Directional Stability: The requirements of
paragraph V of Appendix B are not applicable.
(iii) Dynamic Stability: The requirements of paragraph VI of
Appendix B are replaced with the following two paragraphs:
(A) Any oscillation must be damped, and any aperiodic response must
not double in amplitude in less than 10 seconds. This requirement must
also be met with degraded upper mode(s) of the AFCS. An ``upper mode''
is a mode that utilizes a fully coupled autopilot to provide an
operational SAR profile.
(B) After any speed deviation of 5 knots, the return to the initial
automatic hold condition must occur without oscillation within 10
seconds or less.
(4) With any of the upper mode(s) of the AFCS engaged, the pilot
must be able to manually recover the aircraft and transition to the
normal (Appendix B) IFR flight profile envelope without exceptional
skill, alertness, or strength.
(e) One-Engine Inoperative (OEI) Performance Information. (1) The
following performance information must be provided in the Rotorcraft
Flight Manual Supplement (RFMS):
(i) OEI performance information and emergency procedures, providing
the maximum weight that will provide a minimum clearance of 15 feet
above the surface, following failure of the critical engine in a hover.
The maximum weight must be presented as a function of the hover height
for the temperature and pressure altitude range requested for
certification. The effects of wind must be reflected in the hover
performance information.
(ii) Hover OGE performance with the critical engine inoperative for
OEI continuous and time-limited power ratings for those weights,
altitudes, and temperatures for which certification is requested.
These OEI performance requirements do not replace performance
requirements that may be needed to comply with the airworthiness or
operational standards (Sec. 29.865 or 14 CFR part 133) for external
loads or human external cargo.
(f) RFMS. (1) The RFMS must contain, at a minimum:
(i) Limitations necessary for safe operation of the SAR system to
include:
(A) Minimum crew requirements.
(B) Maximum SAR weight.
(C) Engagement criteria for each of the SAR modes to include MUH.
(ii) Normal and emergency procedures for operation of the SAR
system (to include operation of the hoist operator control), with AFCS
failure modes, AFCS degraded modes, and engine failures.
(iii) Performance information:
(A) OEI performance and height-loss.
(B) Hover OGE performance information, utilizing OEI continuous and
time-limited power ratings.
(C) The maximum wind envelope demonstrated in flight test.
(g) Flight Demonstration. (1) Before approval of the SAR system, an
acceptable flight demonstration of all the coupled SAR modes is
required.
(2) The AFCS must provide fail-safe operations during coupled
maneuvers. The demonstration of fail-safe operations must include a
pilot workload assessment associated with manually flying the aircraft
to an altitude greater than 200 feet above the surface and an airspeed
of at least the best rate of climb airspeed (Vy).
(3) For any failure condition of the SAR system not shown to be
extremely improbable, the pilot must be able to make a smooth
transition from one flight mode to another without exceptional piloting
skill, alertness, or strength.
(4) A failure condition that is not shown to be extremely
improbable must be demonstrated by analysis, ground testing, or flight
testing. For failures demonstrated in flight, the following normal
pilot recognition and recovery times are acceptable (normal pilot
recognition time is the time that it takes an average pilot to
recognize that a failure has occurred):
(i) Transition (Cruise-to-Hover/Hover-to-Cruise) and Hover: Normal
pilot recognition plus 1 second.
(ii) Cruise: Normal pilot recognition plus 3 seconds.
(5) All AFCS malfunctions must include evaluation at the low-speed
and high-power flight conditions typical of SAR operations.
Additionally, AFCS hard-over, slow-over, and oscillatory malfunctions,
particularly in yaw, require evaluation. AFCS malfunction testing must
include a single or a combination of failures (e.g., erroneous data
from and loss of the radio altimeter, attitude, heading, and altitude
sensors) which are not shown to be extremely improbable.
(6) The flight demonstration must include the following
environmental conditions:
(i) Swell into wind.
(ii) Swell and wind from different directions.
(iii) Cross swell.
(iv) Swell of different lengths (short and long swell).
Issued in Fort Worth, Texas, on October 30, 2008.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E8-26462 Filed 11-5-08; 8:45 am]
BILLING CODE 4910-13-P