2013-26406. Special Conditions: Learjet Inc. Model LJ-200-1A10; Airplane Fuselage Post-Crash Fire Survivability

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed special conditions.

SUMMARY:

This action proposes special conditions for the Learjet Inc. Model LJ-200-1A10 airplane. This airplane will have a novel or unusual design feature associated with advanced composite materials in the construction of its fuselage and wings. 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:

Send your comments on or before December 20, 2013.

ADDRESSES:

Send comments identified by docket number FAA-2013-0601 using any of the following methods:

• Federal eRegulations Portal: Go to http://www.regulations.gov/​ and follow the online instructions for sending your comments electronically.
• Mail: Send comments to Docket Operations, M-30, U.S. Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room W12-140, West Building Ground Floor, Washington, DC, 20590-0001.
• Hand Delivery or Courier: Take comments to Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 8 a.m. and 5 p.m., Monday through Friday, except federal holidays.
• Fax: Fax comments to Docket Operations at 202-493-2251.

Privacy: The FAA will post all comments it receives, without change, to http://www.regulations.gov/​,, including any personal information the commenter provides. Using the search function of the docket Web site, anyone can find and read the electronic form of all comments received into any FAA docket, including the name of the individual sending the comment (or signing the comment for an association, business, labor union, etc.). DOT's complete Privacy Act Statementcan be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/​.

Docket: Background documents or comments received may be read at http://www.regulations.gov/​ at any time. Follow the online instructions for accessing the docket or go to the Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except federal holidays.

FOR FURTHER INFORMATION CONTACT:

Alan Sinclair, Airframe/Cabin Safety Branch, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98057-3356; telephone [phone]; facsimile 425-227-1320; email [e-mail].

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 will consider all comments we receive on or before the closing date for comments. We may change these special conditions based on the comments we receive.

Background

On February 9, 2009, Learjet Inc. applied for a type certificate for their new Model LJ-200-1A10.

The Model LJ-200-1A10 is a business-class airplane with two high-bypass turbine engines and interior seating configuration for up to 10 passengers.

The Model LJ-200-1A10 is the first airplane manufactured by Learjet Inc. to utilize advanced composite materials in the construction of its fuselage and wings.

This proposed special condition is necessary to ensure a level of safety equivalent to that provided by 14 CFR part 25. Regulations applicable to burn requirements, including §§ 25.853 and 25.856(a), remain valid for this airplane but do not reflect the threat generated from toxic levels of gases produced from carbon-fiber/resin system materials following a post-crash fire scenario.

Type Certification Basis

Under the provisions of Title 14, Code of Federal Regulations (14 CFR) 21.17, Learjet Inc. must show that the Model LJ-200-1A10 meets the applicable provisions of part 25, as amended by Amendments 25-1 through 25-127.

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 Model LJ-200-1A10 because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.

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 under § 21.101.

In addition to the applicable airworthiness regulations and special conditions, the Model LJ-200-1A10 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 § 611 of Public Law 92-574, the “Noise Control Act of 1972.”

The FAA issues special conditions, as defined in 14 CFR 11.19, in accordance with § 11.38, and they become part of the type-certification basis under § 21.17(a)(2).

Novel or Unusual Design Features

The Model LJ-200-1A10 will incorporate the following novel or unusual design features:

The Model LJ-200-1A10 is the first airplane manufactured by Learjet Inc. to utilize advanced composite materials in the construction of its fuselage and wings. In accordance with § 21.16, fuselage structure fabricated from monolithic carbon-fiber reinforced plastic (CFRP) prepreg material (reinforcement fiber pre-impregnated with a thermoplastic or thermoset resin matrix) constitutes a novel and unusual design feature for a large transport-category airplane certificated under 14 CFR part 25.

Discussion

Existing regulations do not adequately ensure that composite structure offers passengers the same protection from an on-ground, post-crash fire condition as would a conventional aluminum structure. Learjet is introducing a new material that may have different toxicity characteristics than those of traditional materials. Service experience has shown that, in post-crash fires, traditional aluminum structural materials emit acceptable toxicity levels. Therefore, it is necessary to ensure that the material being utilized does not reduce the survivability of the passengers during a post-crash fire or provide levels of toxic fumes that would be lethal or incapacitating, preventing evacuation of the aircraft following a crash scenario. This proposed special condition is necessary to ensure a level of safety equivalent to that provided by 14 CFR part 25. Regulations applicable to burn requirements, including §§ 25.853 and 25.856(a), remain valid for this airplane but are not sufficient to address the potential hazard from toxic levels of gases that might be produced from carbon fiber/resin system materials during a post-crash fire.

Applicability

As discussed above, these special conditions are applicable to the Model LJ-200-1A10. Should Learjet Inc. apply at a later date for a change to the type certificate to include another airplane 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 airplanes. It is not a rule of general applicability.

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 Proposed Special Conditions

Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for Learjet Inc. Model LJ-200-1A10 airplanes.

The Learjet Model LJ-200-1A10 must show that toxic levels of gases produced from the composite-material system are in no way an additional threat to the passengers and their ability to evacuate when compared to an aluminum-constructed aircraft.

Issued in Renton, Washington, on October 18, 2013.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.