Comair, Inc.

These comments are submitted on behalf of Comair, Inc. Request to revise or supersede AD 2006-12-21. The preamble of this NPRM, and similar statement by Paragraph (i), contains the following statement under the paragraph entitled Method of Compliance With AD 2006-12-21: Installing flap actuators in accordance with paragraph (h)(5) of the proposed AD is acceptable for compliance with the installation of Number 3 and Number 4 flap actuators required by paragraph (h) of AD 2006-12-21, Amendment 39-14647 (71 FR 34793, June 16, 2006), for that actuator only. The remaining requirements of paragraph (h) of AD 2006-12-21 remain in effect. While such a statement is beneficial, there will still be no reference within AD 2006-12-21 indicating installation of these new Number 3 & 4 actuators part numbers are acceptable. Paragraph (h)(2) Note 1 and again in (h)(2)2 Note: The fuel burn factor (as per AFM TR/165) shall be… This reference should be changed to AFM TR/165-1. Paragraphs (f)(3), (g)(1) & (h)(3) Training requirements: This comment is to challenge whether an airworthiness directive is the proper mechanism to mandate specific flight crewmember and operational control/dispatch personnel training. Part 39.3 definition of airworthiness directives states “airworthiness directives are legally enforceable rules that apply to the following products: aircraft, aircraft engines, propellers, and appliances.” These paragraphs requiring training are issued against people and not against a product. It should be considered the FAA is issuing a requirement which is beyond the capacity or scope of an airworthiness directive. Paragraph (g)(3). In recent years it seems to have become common practice when an AD is superseded by another AD that the old requirements are restated as they appeared in the superseded AD. Paragraph (g)(3)(i) and (ii) of AD 2008-01-04 makes reference to “2,000 flight hours”. Paragraph (g)(3)(i) and (ii) of this NPRM now list “5,000 flight cycles”. If this is a new requirement, for consistency, it should fall under Paragraph (h). (h)(2) 4. Dispatch Following a Flap Failed Event - reasoning Language regarding the actions following a flap reset can be clarified for operational application: --Flight crew system tests: That there is no requirement to document the results should be clarified. --Flight crew system tests: The cycling of the flaps through five cycles applies only to the first flight following the flap reset. This distinction should be clarified. --Flight crew system tests: The term take-off, instead of dispatch, should be used for the following tests, to allow the crew to perform them during taxi out: --thrust reverse --ground spoiler -- brake system --The listing for conditions a/b/c/d can be clarified. Suggested Language: (h)(2) 4. Dispatch Following a Flap Failed Event If normal flap system operation can be restored after an on-ground system reset, continued revenue operation of that airplane is permitted. The following two paragraphs are applicable to operations following an on-ground system reset: The following actions must be performed by the flight crew following an on-ground circuit breaker reset: Note: No maintenance log entry is required for the following action. For the first flight following an on-ground circuit breaker reset, prior to dispatch, the flaps must be operated for five full extension/retraction cycles with no subsequent failures. For each flight following an on-ground circuit breaker reset, prior to take-off, the following checks must be performed: a. Thrust Reversers--cycle (Note: AFM Chapter 2 Limitations apply) b. Ground Spoilers--confirm operational (Note: Verify using MAN ARM position and FLIGHT CONTROLS EICAS page) c. Brake System--confirm operational (Note: Verify by confirming both pilots rudder pedal brakes are operational and HYDRAULIC EICAS page indicates normal pressures) Until a maintenance action can be performed as specified by (h)(3)(6), for each flight following an on-ground circuit breaker reset, either condition a. or b., below, must be satisfied: a. The Landing Distance Available on a useable runway at the destination airport is at least equal to the actual landing distance required for flaps zero. This distance shall be based on Bombardier performance data, and shall take into account forecast weather and anticipated runway conditions. b. The Landing Distance Available on a useable runway at the filed alternate airport, or other suitable airport is at least equal to the actual landing distance for flaps zero. This distance shall be based on Bombardier performance data, and shall take into account forecast weather and anticipated runway conditions. Note 1: If the forecast destination weather is less than 200 feet above DH or MDA, or less than 1 mile (1500 meters) above the authorized landing visibility (or equivalent RVR), as applied to the usable runway at the destination airport, condition b. above must be satisfied. Note 2: When conducting No Alternate IFR (NAIFR) operations, condition a. above must be satisfied. Paragraph (h)(4) Part IV. New Maintenance Action. Clarification on the intent of this paragraph. Many of the actuators at Comair fell into the category covered by Paragraph (g)(3)(i) and (ii) and no additional action for Paragraph (g)(3) was required. Is the intent of this new maintenance action to require a respective low temperature torque test even for those actuators for which no action was required under Paragraph (g)(3)? Request for a phase-in period. A number of actuators have compliance of SB 601R- 27-150 from as early as February 15, 2008. It is unlikely this NPRM will supersede AD 2008-01-04 before February 15, 2009 and some actuators will already have exceeded 12 months since last compliance. Since under AD 2008-01-04 Paragraph (g)(3) was only a one time compliance, and paragraph (h)(4) will now make that repetitive, a phase-in is necessary for actuators having early compliance. A suggested statement for Paragraph (h)(4) is “Within 12 months after doing the low temperature torque test specified in paragraph (g)(3) or 60 days after the effective date of this AD, whichever is later, do the low temperature torque test…….” Paragraph (h)(6)Part V. “Dispatch following a flap fail event: For airplanes on which a flap fail message occurs, prior to further flight, do all applicable maintenance actions in accordance with Section 27-50-00 of the Bombardier CRJ100/200/440 Fault Isolation Manual (FIM) CSP A- 009, Revision 38, dated January 10, 2008.” The FAA is setting Operators up for a noncompliance scenario by listing a specific Fault Isolation Manual revision. Operators have no control over Bombardier revisions. Paragraph (h)(6) and (7) Part V. Both of the above referenced paragraphs are listed as Part V and perhaps an editorial error. Paragraph (7) Part V. We request that a two year limit be placed on the reporting requirements of this AD. Enough data should be provided in a two year time period to support any fault monitoring.