u.s. Department 

of Transportation 

Federal Aviation 

Administration 

JUN 1 4 10Gl 

Mr. Craig Bolt 

Assistant Chair 

Transport Airplane and Engine Issues Group 

Aviation Rulemaking Advisory Committee 

Pratt & Whitney 

400 Main St. 

E. Hartford, CT 06108 

Dear Mr. Bolt: 

This letter is a follow-up to my letter to you of January 26, 2005. In that letter we 

promised to identify the alternative actions to the Aviation Rulemaking Advisory 

Committee CARAe) recommendations that were not listed in our Regulatory Program 

Review. Those alternative actions are on the attached list. If you have any question on 

the actions on this list please contact Mr. Brian A. Yanez at 202-267-5864. 

Once again we value your comments on how we address ARAC recommendations. We 

appreciate your support in developing these recommendations. 

Sincerely, 

John 1. Hickey 

Director, Aircraft Certification Service 
AVS "Do By Other Means" Projects Follow-Up 

Project Title "Other Means" 

Certification of New Propulsion Technologies Currently, FAA is able to offer airworthiness requirements for these 

technologies via Special Conditions. Industry is in agreement with this 

on Part 23 Airplanes aoproach. 

We have linked this rulemaking effort with the Part 135 Aviation 

Jet and High Performance Part 23 Airplanes Rulemaking Committee (ARC). Until this work is completed, FAA will 

continue the use of Special Conditions to establish airworthiness 

renuirements for the lanes. 

Standardization of Improved Small Airplane This rule ties In with the spin resistance of airplanes_ This rule would not Normal Category Stall Characteristics be relieving in nature. This rulemaking will proceed when rulemaking Requirements (23.777, 23.781, 23.1141, 

23.1309,23.1337,23.1305\ resources become available. 

(Beta) Reverse Thrust and Propeller Pitch The JAA and EASA have adopted this rule into change 16 of the JAR and 

Settings Below the Flight Regime (NPRM), CS-25, respectively. The FAA will recategorize this project as enveloping 

25.1155 rulemakinq. 

Since the ARAC HWG was unable to reach agreement on an acceptable 

Bird Strike rule revision, the FAA does not plan to implement this project through 

"other means". 

This ARAC recommendation may be voluntarily used as a basis for an 

Casting Factors, 25.621 equivalent level of safety finding reql~~.st (per Transport Airplane 

Directorate nolicv memo dated 1/4/01 . 

This ARAC recommendation will continue to be applied to new certification 

Fast Track Harmonization Project: Engine and projects as a Special Condition (the size, configuration and failure modes 

APU Loads Conditions, 25.3611.362 (ARAC) of jet engines has changed considerably from those envisioned when the 

oriainal enoine seizure rule was first adootedl. 

Fire Protection of Engine Cowling, This ARAC recommendation may be voluntarily used as a basis for an 

equivalent level of safety finding request (per Transport Airplane 25.1193(e)(3) (NPRM) Directorate oolicv memo dated 114/01 I. 

This ARAC recommendation will be removed from the Do By Other Means 

Flight Loads Validation (ARAC), 25.301 category because the recommendation only contained a draft AC (no 

rulemakino\. 

There IS no ARAC recommendation associated with this project as the 

Fuel Vent System Fire Protection tasking was withdrawn by the FAA on 6/15/04. Since the FAA will not be 

- Retrofit Rule for Part 121, 125, and 135 Only pursuing an operational rule, as originally planned, we will continue to 

(Final) issue ADs, as appropriate, to address existing fleet issues. The FAA will 

- Part 25 Rule also prevent certificatio~~~ an unsafe design feature/characteristic using 

the p'rovisions of 21.21(b (21-

The JAA and EASA have adopted this rule into change 16 of the JAR and 

Ground Gust Conditions (RPR), 25.415 CS-25, respectively. The FAA will recategorize this project as enveloping 

rulemakino. 

Harmonization of Airworthiness Standards The JAA and EASA have adopted this rule into change 16 of the JAR and 

Flight Rules, Static Lateral-Directional CS-25, respectively. The FAA will recategorlze this project as enveloping 

Stability, and Speed Increase and Recovery 

Characteristics'(NPRM\,25.177 

rulemaking. 

Use of AC 20-135 to demonstrate fireproof and fire resistant 

Harmonization of Part 1 Definitions Firep"oof characteristics results in an adequate level of safety. For cases where AC 

and Fire Resistant (RPR) 20-135 is used as a method of compliance, the FAA would not need to use 

the provisions of 21.21(b)(2). 

Loads and Dynamics - Continuous This ARAC recommendation may be voluntarily used as a basis for an 

equivalent level of safety finding request (per Transport Airplane Turbulence Loads, 25.341(b) Directorate DOlicv memo dated 1141011. 
For future certification projects, the FAA plans to revise the eXisting Issue 

Restart Capability (ARAC) Paper, based on the ARAC recommendation, to prevent certification of an 

unsafe feature/characteristiC under the provisions of section 21.21 (b)(2). 

The portion of the ARAC recommendation related to a lack of ATTCS onoff switch and performance credit with reduced take-off thrust, may be 

voluntarily used as a basis for an equivalent level of salety finding request 

Automatic Takeoff Thrust Control System (per Transport Airplane Directorate policy memo dated 114/01), 

The portion of the ARAC recommendation concerning <lddltionai (ATTCS), 25.904, App I certification requirements for go-arounds may be applied to new projects 

as a SpeCial Condition (Hle onginal rules related to ATTCS did not 

consider performance credit for go-around conditions). 

The references to 25,855 and 25 857 should not be associated with this 

project and will be removed. The FAA does have a rulemaklng project 

associated with the ARAC recommendation for 25.855 and 25,857 (Class 

Cargo Compartment Fire Exlingulshlflg or 

B and Class F cargo compartments). The 

ARAC recommendation associated with 25.851 (b) may be voluntarily used Suppression Systems, 25,851 (b), 25.855, 

as a basis for an equivalent level of safety finding request (per Transport 25.857 Airplane Directorate poliCy memo dated 1/4/01). The AC material 

associated with that ARAC recommendation would also be considered a 

method of direct compliance with the existing 25.851(b}, 

ThiS ARAC recommendation may be voluntarily used as a basis for an 

Proof of Structure, 25,307 equivalent level of safety finding request (per Transport Airptane 

Directorate poliCY memo dated 1/4/011. 

Since the ARAC HWG was unable to reach agreement on an acceptable 

rule rev'lsion, the FAA does not plan to implement this project through 

High Altitude Flight 25.365(d) "other means". However, the FAA Interim policy proVides gUidance for 

requesting an exemption until a final rule IS adopted. 

Damage-Tolerance and Fatigue Evaluation of This ARAC recommendation may be voluntarily used as a basis for an 

equivalent level of safety finding mquest (per Tra'lsport Airplane Structure, 25.571 Directorate policv memo dated 114/011. 

This ARAC recommendation will be removed from the Do By Other Means 

Material Properties, 25.603 category because the recommendation only contained a draft AC (no 

rulemakinq1. 

Fire Protection 33,17 See Note 1 Below 

Rotor Integrit Overs eed 33.27 See Note 1 Below 

Safet Anal SIS 33,75 See Note 1 Below 

Rotor Integrity - Over-torque 33.84 See Note 1 Below 

2 Minute/3~ Second One Engine Inoperative See Note 1 Below 

OEI) (33XX) -

Electrical and Electronic Engine Control See Note 1 Below 

S stems (33.28) 

Note 1: EASA CS-E certification specification can be vuluntarily used as an 

alternate to the corresponding 14 CFR Part 33 requirements under a 14 

CFR § 21.29(a){1 )(Ii) eqUivalent levet of safety frndlng However, it will be 

necessary for the E&PD to review each project on a case-by-case basis to 

ensure that there are no unique Circumstances that woutd invalidate the 

acceptability of this approach. If this approach IS accepted by the E&PD, 

the corresponding CS-E specification must be used in it's entirety.