Exemption No. 11092 

UNITED STATES OF AMERICA 

DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRA TlON 

WASHINGTON, DC 20591 

In the matter of the petition of 

CIRRUS DESIGN 

CORPORATION 

for an exemption from § 23 .177(b) of 

Title 14, Code of Federal Regulations 

Regulatory Docket No. FAA 2014-0533 

GRANT OF EXEMPTION 

By letter dated July 23, 2014, Mr. Tom Engelmann, Certification Engineer, Cirrus Design 

Corporation (Cirrus), 451 5 Taylor Circle, Duluth, MN 55811 petitioned the Federal Aviation 

Administration (FAA) on behalf of Cirrus for an exemption from § 23.177(b) of Title 14, 

Code of Federal Regulations (14 CFR). The proposed exemption, if granted, would allow type 

certification of the Cirrus Model SFSO without a Rudder-Aileron Interconnect (RAJ). 

The petitioner requests relief from the following regulation: 

Section 23.177(b), in pertinent part, states: 

" (b )(1) The static lateral stability, as shown by the tendency to raise the 

low wing in a sideslip with the aileron controls free, may not be negative 

for any landing gear and flap position appropriate to the takeoff, climb, 

cruise, approach, and landing configurations. This must be shown with 

symmetrical power from idle up to 75 percent of maximum continuous 

power at speeds from 1.2 V s1 in the takeoff configuration(s) and at speeds 

from 1.3 V s 1 in other configurations, up to the maximum allowable 

airspeed for the configuration being investigated (V FE, Y LE, Y No, Y Fc/MFc, 

whichever is appropriate) in the takeoff, climb, cruise, descent, and 

approach configurations. For the landing configuration, the power must be 

that necessary to maintain a 3-degree angle of descent in coordinated 

flight. 

(2) The static lateral stability may not be negative at 1.2 Ys 1 in the takeoff 

configuration, or at 1.3 V s 1 in other configurations. 

ACE-14-409-E 
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(3) The angle of sideslip for these tests must be appropriate to the type of 

airplane, but in no case may the constant heading sideslip angle be less 

than that obtainable with a I 0 degree bank or, if less, the maximum bank 

angle obtainable with full rudder deflection or 150 pound rudder force." 

The petitioner supports its request with the following information: 

The petitioner states on the SR20 and SR22 the rudder aileron interconnect introduced a 

higher level of complexity into the flight control system and was the subject of several Service 

Bulletins as well as an Airworthiness Directive (AD) on the previous Cirrus Models SR20 and 

SR22. To avoid similar issues with the SF50, Cirrus is requesting an exemption to simplify 

maintainability without detrimental effect on operational safety. 

The FAA has determined that good cause exists for waiving the requirement for Federal 

Register publication because the exemption, if granted, would not set a precedent, and any 

delay in acting on this petition would be detrimental to Cirrus. 

The FAA's analysis is as follows: 

The FAA recognizes relief granted in another similar circumstance as presented in your 

petition. Exemption No. 10923 granted relieffrom § 23.177(b) to the SR20/22 Cirrus model 

series. This exemption yielded no comments when it was published in the Federal Register 

(75 FR 73919). The FAA has reviewed your reasons for requesting an exemption and frnds 

that1. Flight test results show the level ofsafety provided by§ 23.177(b) remains 

satisfactory. Cirrus has demonstrated the use of the electric roll trim control system, as 

part of the approved type design, for lateral control in the event the primary roll 

controls system becomes disconnected; 

2. Flight test show that with the RAI removed, all other subpart B rules remain 

compliant; 

3. The reasons stated by the FAA for granting the previous relief (Exemption l 0923) also 

applies to this Cirrus design; and 

4. A grant of exemption is in the public interest. 

The FAA's Decision 

In consideration of the foregoing, I find that a grant of exemption is in the public interest. 

Therefore, pursuant to the authority conta ined in 49 U.S.C. §§ 106(f), 40113 and 44701 , 

delegated to me by the Administrator, Cirrus Design Corporation is granted an exemption 

from 14 CFR 23 .177(b) to the extent necessary to allow Cirrus to remove the Rudder-Aileron 
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interconnect (RAI) from the Cirrus SF50 airplane, subject to the conditions and limitations 

listed below. 

Conditions and Limitations 

1. The Airplane Flight Manual (AFM) Limitations must show that the electric roll trim 

system must be operational for flight. 

Issued in Kansas City, MO, on October 23 , 2014 . 

ld~ Earl Lawrence 

Manager, Small Airplane Directorate 

Aircraft Certification Service