Special Conditions: Cessna Aircraft Company, Model 525C; Single Point Refuel/Defuel System

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed special conditions.

SUMMARY:

This action proposes special conditions for the Cessna Model 525C airplane. This airplane will have a novel or unusual design feature(s) associated with a Single Point Refuel/Defuel system. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed 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:

We must receive your comments by May 15, 2009.

ADDRESSES:

Mail two copies of your comments to: Federal Aviation Administration, Regional Counsel, ACE-7, Attention: Rules Docket, Docket No. CE294, 901 Locust, Room 506, Kansas City, Missouri 64106. You may deliver two copies to the Regional Counsel at the above address. Mark your comments: Docket No. CE294. 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:

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 concerning these special conditions. You may inspect the docket before and after the comment period 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 your 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.

Background

On August 9, 2006, Cessna Aircraft Company applied for an amendment to Type Certificate Number A1WI to include the new model 525C (CJ4). The model 525C (CJ4), which is a derivative of the model 525B (CJ3) currently approved under Type Certificate Number A1WI, 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. The maximum takeoff weight is 16,650 pounds, the V_MO/M_MO is 305 KIAS/M 0.77 and maximum altitude is 45,000 feet.

The model 525C fuel system will incorporate a Single Point Refuel/Defuel system. The model 525C Single Point Refuel/Defuel system is used to pressure refuel and defuel the left and right wing fuel tanks from a single refuel/defuel adapter. The system is operated by fuel level and positive refuel or negative defuel pressure. This system is similar in design to other 14 CFR part 25 Cessna Citation airplanes and uses many of the same components that are used in these other airplanes. The components for the model 525C refuel/defuel system include a refuel/defuel adapter, a precheck valve, various other check valves, a high level pilot valve, a refuel valve, a defuel valve, and a positive/negative relief valve. Single point refueling is accomplished by connecting the refuel equipment to the refuel/defuel adapter and applying positive pressure. Fuel is directed through a common manifold to each wing tank's fuel shutoff (refuel) valve. Single point defueling is accomplished by connecting defuel equipment to the refuel/defuel adapter and applying negative pressure. Defueling is controlled by fuel level and negative pressure from the defuel equipment.

The incorporation of a pressure defueling system was not considered when 14 CFR part 23 was created; thus, there are no applicable certification requirements for this novel and unusual design feature. Pressure defueling systems are more common on part 25 airplanes, and the applicable certification requirements are contained in part 25, section 25.979(e), which states: “The airplane defueling system (not including fuel tanks and fuel tank vents) must withstand an ultimate load that is 2.0 times the load arising from the maximum permissible defueling pressure (positive or negative) at the airplane fueling connection.” With the pressure defueling system design incorporated on the model 525C it is necessary to apply a special condition to this novel and unusual design feature.

Type Certification Basis

Under the provisions of section 21.101, Cessna Aircraft Company must show that the model 525C meets the applicable provisions of the regulations incorporated by reference in Type Certificate Number A1WI or the applicable regulations in effect on the date of application for the change to the model 525B. The regulations incorporated by reference in the type certificate are commonly referred to as the “original type certification basis.” In addition, the certification basis includes exemptions, if any; equivalent level of safety findings, if any; and the special condition adopted by this rulemaking action.

If the Administrator finds that the applicable airworthiness regulations in part 23 do not contain adequate or appropriate safety standards for the model 525C because of a novel or unusual design feature, special conditions are prescribed under the provisions of section 21.16.

In addition to the applicable airworthiness regulations and special conditions, the model 525C 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.

The FAA issues special conditions, as appropriate, as defined in section 11.19, under section 11.38, and they become part of the type certification basis under section 21.101.

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, or should any other model already included on the same type certificate be modified to incorporate the same novel or unusual design feature, the special conditions would also apply to the other model under the provisions of section 21.101.

Novel or Unusual Design Features

The model 525C will incorporate the following novel or unusual design features:

A single point refuel/defuel system.

Applicability

As discussed above, these special conditions are applicable to the model 525C. Should Cessna 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.

Conclusion

This action affects only certain novel or unusual design features on one model of 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 23

• Aircraft
• Aviation safety
• Signs and symbols

Citation

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 Proposed Special Conditions

Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for Cessna Aircraft Company model 525C airplanes.

1. SC25.979(e)

The airplane defueling system (not including fuel tanks and fuel tank vents) must withstand an ultimate load that is 2.0 times the load arising from the maximum permissible defueling pressure (positive or negative) at the airplane fueling connection.