05-122. Special Conditions: Raytheon Model 4000 Horizon; Side-Facing Single-Occupant Seats

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final special conditions; request for comments.

SUMMARY:

These special conditions are issued for the Raytheon Model 4000 Horizon airplane. This airplane will have a novel or unusual design feature associated with side-facing single-occupant seats. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards 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 22, 2004. Send your comments on or before February 22, 2005.

ADDRESSES:

Comments on these special conditions may be mailed in duplicate to: Federal Aviation Administration, Transport Airplane Directorate, Attn: Rules Docket (ANM-113), Docket No. NM297, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; or delivered in duplicate to the Transport Airplane Directorate at the above address. Comments must be marked: Docket No. NM297. Comments may be inspected in the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT:

John A. Shelden, FAA, Airframe/Cabin Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone], facsimile [phone].

SUPPLEMENTARY INFORMATION:

The substance of these special conditions has been subject to the notice and comment period in several prior instances and has been derived without substantive change from those previously issued. For this reason, and 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. We are requesting comments to allow interested persons to submit views that may not have been submitted in response to the prior opportunities for comment.

Comments Invited

We invite interested persons to participate in this rulemaking by submitting 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 concerning these special conditions. The docket is available for public inspection 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 in light of the comments we receive.

If you want the FAA to acknowledge receipt of your comments on these special conditions, 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.

Background

On August 1, 1996, Raytheon Aircraft Company, 9709 E. Central, Wichita, KS 67201, applied for a type certificate for their new Model 4000 Horizon airplane and reapplied on May 31, 2001. The Model 4000 Horizon is a twin-engine, pressurized executive jet airplane with standard seating provisions for 10 passenger/crew and allowance for baggage and optional equipment. This airplane will have a maximum takeoff weight of 36,000 pounds and will have two aft-mounted Pratt & Whitney PW 308A engines.

Type Certification Basis

Under the provisions of 14 CFR 21.17, the Raytheon Aircraft Company must show that the Model 4000 Horizon airplane meets the applicable provisions of part 25, effective February 1, 1965, as amended by amendment 25-1 through amendment 25-101.

If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the Raytheon Model 4000 Horizon airplane because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.

In addition to the applicable airworthiness regulations and special conditions, the Raytheon Model 4000 Horizon must comply with the fuel vent and exhaust emission requirements of part 34, effective September 10, 1990, as amended by any amendment in effect on the date of certification, and the noise certification requirements of part 36, effective December 1, 1969, as amended by any amendment in effect on the date of certification, and the FAA must issue a finding of regulatory adequacy pursuant to § 611 of Public Law 92-574, the “Noise Control Act of 1972.”

Special conditions, as defined in § 11.19, are issued in accordance with § 11.38 and become part of the type certification basis in accordance with § 21.17.

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 novel or unusual design feature, the special conditions would also apply to the other model under the provisions of § 21.101.

Novel or Unusual Design Features

The Raytheon Model 4000 offers interior arrangements, which include single-occupant side-facing seat installations. One arrangement includes an aft LH toilet installation, which will be approved for occupancy during taxi, takeoff, and landing. The belted toilet seat is a single-occupant side-facing seating system located directly behind the LH aft pocket door partition. It consists of a toilet assembly, toilet cabinet, forward partition, contact pad, and restraint system (lap belt).

Section 25.785(b) requires that “each seat * * * at each station designated as occupiable during takeoff and landing must be designed so that a person making proper use of these facilities will not suffer serious injury in an emergency landing as a result of the inertia forces specified in §§ 25.561 and 25.562.” Additionally, § 25.562 requires dynamic testing of all seats occupied during takeoff and landing. Side-facing seats, however, are considered a novel design for transport category airplanes that include amendment 25-64 in the certification basis, and were not considered when those airworthiness standards were established. Hence, the existing regulations do not provide adequate or appropriate safety standards for occupants of side-facing seats. In order to provide a level of safety that is equivalent to that afforded occupants of forward and aft-facing seats, additional airworthiness standards, in the form of special conditions, are necessary.

Discussion

The following special conditions are considered to provide occupants of single occupancy side-facing seats a level of safety that is equivalent to that afforded occupants of forward and aft-facing seats. These special conditions supplement part 25 and, more specifically, they supplement §§ 25.785 and 25.562.

Applicability

As discussed above, these special conditions are applicable to the Raytheon Model 4000 Horizon. Should Raytheon Aircraft Company apply at a later date 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 under the provisions of § 21.101.

Conclusion

This action affects only certain novel or unusual design features on the Raytheon Model 4000 Horizon airplane. It is not a rule of general applicability, and it affects only the applicant who applied to the FAA for approval of these features on the airplane.

List of Subjects in 14 CFR Part 25

• Aircraft
• Aviation safety
• Reporting and recordkeeping requirements

The authority citation for these special conditions is as follows:

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

The Special Conditions

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 the Raytheon Model 4000 Horizon airplane.

In addition to the airworthiness standards of §§ 25.562 and 25.785, the minimum acceptable standards for dynamic certification of Raytheon Model 4000 Horizon single-occupant side-facing seats are as follows:

Additional Injury Criteria

(a) Existing Criteria: All injury protection criteria of § 25.562(c)(1) through (c)(6) apply to the occupant of a side-facing seat. Head Injury Criterion (HIC) assessments are required only for head contact with the seat and/or adjacent structures.

(b) Body-to-Wall/Furnishing Contact: The seat must be installed aft of a structure, such as an interior wall or furnishing, that will support the pelvis, upper arm, chest, and head of an occupant seated next to the structure. A conservative representation of the structure and its stiffness must be included in the tests. It is recommended, but not required, that the contact surface of this structure be covered with at least two inches of energy-absorbing protective padding (foam or equivalent), such as Ensolite.

(c) Thoracic Trauma: The Thoracic Trauma Index (TTI) injury criterion must be substantiated by dynamic test or by rational analysis, based on a previous test or tests of a similar seat installation. Testing must be conducted with a Side Impact Dummy (SID), as defined in 49 CFR part 572, Subpart F, or its equivalent. TTI must be less than 85, as defined in 49 CFR part 572, Subpart F. TTI data must be processed as defined in Federal Motor Vehicle Safety Standard (FMVSS) part 571.214, section S6.13.5.

(d) Pelvis: Pelvic lateral acceleration must be shown by dynamic test or by rational analysis based on previous test(s) of a similar seat installation to not exceed 130g. Pelvic acceleration data must be processed as defined in FMVSS part 571.214, section S6.13.5.

(e) Shoulder Strap Loads: Where upper torso straps (shoulder straps) are used for occupants, tension loads in individual straps must not exceed 1,750 pounds. If dual straps are used for restraining the upper torso, the total strap tension loads must not exceed 2,000 pounds.

Additional Test Requirements

The above performance measures must not be exceeded during the following dynamic tests:

(a) Conduct a longitudinal test per § 25.562(b)(2) with a SID, undeformed floor, no yaw, and with all lateral structural supports (armrests/walls).

Pass/fail injury assessments: TTI and pelvic acceleration.

(b) Conduct a longitudinal test per § 25.562(b)(2) with the Hybrid II ATD, deformed floor, 10 degrees yaw, and with all lateral structural supports (armrests/walls).

Pass/fail injury assessments: HIC, upper torso restraint load, restraint system retention and pelvic acceleration.

(c) Conduct a vertical test per § 25.562(b)(1) with a Hybrid II ATD with existing pass/fail criteria.

Issued in Renton, Washington, on December 22, 2004.

Kevin Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.