AD 96-11-08 — Aircraft-logs.com

96-11-08 ROBINSON HELICOPTER COMPANY: Amendment 39-9633. Docket No. 95-SW-27-AD. Supersedes AD 82-23-51, Amendment 39-4645.

Applicability: Model R22 helicopters, serial numbers (S/N) 0002 to 2537, certificated in any category.

NOTE 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required within 30 days after the effective date of this AD, unless accomplished previously.

To minimize the possibility of pilot mismanagement of the main rotor (M/R) revolutions-per-minute (RPM), which could result in unrecoverable M/R blade stall and subsequent loss of control of the helicopter, accomplish the following:

(a) Adjust the A569-1 or -5 low-RPM warning unit so that the warning horn and caution light activate when the M/R RPM is between 96% and 97% rotor RPM in accordance with the procedures contained in the Model R22 maintenance manual.

(b) For Model R22 helicopters that do not have a governor currently installed, install a Robinson Helicopter Company KI-67-2 Governor Field Installation Kit in accordance with the kit instructions.

(c) For Model R22 helicopters that have a throttle/collective governor currently installed, upgrade the governor with a Robinson Helicopter Company KI-67-3 Governor Upgrade Kit in accordance with the kit instructions.

(d) Upon accomplishment of paragraphs (b) or (c) of this AD, revise the FAA-approved Robinson Helicopter Company R22 Rotorcraft Flight Manual (RFM) to include the following statement in the Flight and Maneuver Limitations section. This may be accomplished by inserting a copy of this AD into the RFM.

"Flight prohibited with governor selected off, with exceptions for inflight system malfunction or emergency procedures training."

(e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office, FAA. Operators shall submit their requests through FAA Principal Maintenance Inspectors, who may concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office.NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles Aircraft Certification Office.

(f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished.

(g) This amendment becomes effective July 2, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 82-23-51, Amendment 39-4645, (48 FR 21894, May 16, 1983), which is applicable to Robinson Helicopter Model R22 helicopters, was published in the Federal Register on December 14, 1995 (60 FR 64129). That action proposed to require installation of an improved throttle governor; an adjustment to the warning unit threshold to increase the RPM at which the warning horn and caution light activate; and, revisions to the R22 Rotorcraft Flight Manual.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Discussion of Comments

Eight commenters responded to the NPRM. These commenters are the National Transportation Safety Board (NTSB), Helicopter Association International (HAI), Helicopter Association of Australia, Civil Aviation Safety Authority Australia, the Robinson Helicopter Association, the manufacturer, and two helicopter operators. Comments were received on the proposal to increase the threshold of the low rotor RPM warning unit, the proposal to require installation of the improved throttle governor, the proposal to limit operations with the governor selected off, and proposed Rotorcraft Flight Manual (RFM) changes and other general comments. The commenters' positions and the FAA response to each of these positions are summarized as follows:

Increase in Threshold of Warning Unit

Three commenters support and no commenters object to the proposal to increase the low rotor RPM warning unit horn and caution light threshold from 95+1% RPM to between 96% and 97% RPM. Therefore, the proposal is adopted as proposed.

Installation of Improved Throttle Governor

Three commenters support and five commenters oppose the proposal to require installation of a throttle governor on all Model R22 helicopters. The two commenters from Australia oppose mandating installation of a throttle governor and state that although the throttle governor would reduce pilot workload and enhance public safety, mandatory installation of the governor is unnecessary since no conclusive evidence exists to indicate that a Model R22 accident in their country was caused by abnormally low RPM. Therefore, very few accidents would have been prevented with a governor installed. Additionally, these two commenters suggest that the FAA allow more time to determine whether implementation of Special Federal Aviation Regulation (SFAR 73) on March 27, 1995, mandating awareness training for low time pilots and special training requirements for flight instructors, will necessitate any further safety action.

Another commenter states that the improved throttle governor is not necessary based upon their analysis of the National Transportation Safety Board (NTSB) accident data for the Model R22 from January 1992 to December 1995. The commenter noted that the overall number of R22 accidents declined with the implementation of SFAR 73 and the issuance of Airworthiness Directive 95-11-09, effective July 14, 1995, prohibiting low "g" maneuvers.

Another commenter states that recent accident statistics show that no R22 accident in 1995 could be attributed to low rotor RPM. The commenter states that the awareness training has had a positive effect and that mechanical solutions should be deleted or put on hold until evidence is available which indicates that the proposed changes are necessary.

A fifth commenter states that the proposal to require installation of the improved throttle governor may not increase safety in any way and may cause additional accidents since some low time pilots may become too reliant on the governor and not realize other difficulties such as carburetor icing.

The FAA does not concur. Although accident data presented indicates that low rotor stall due to improper throttle management has not resulted in recent R22 accidents, several of the 31 fatal accidents in the period from 1981 to the present involving main rotor to fuselage contact have exhibited signs of low rotor stall due to low rotor RPM. Accident records provided by the NTSB indicate that there were 33 non-fatal accidents in a 10 year period, from June 1985 to June 1995, in which failure to maintain rotor RPM was a casual factor. These accidents all resulted in at least substantial damage to the airframe. The FAA's recently completed study indicates that the potential exists for these types of accidents due to throttle mismanagement. Installation of the improved throttle governor will reduce the possibility of throttle mismanagement.

Even with the improved training, as stipulated in SFAR 73, the possibility of M/R stall due to throttle mismanagement still exists. The current R22 fleet consists of helicopters that have no governors, and that have either throttle/collective governors or throttlegovernors. The FAA considers issuance of this AD to be necessary due to the different operating characteristics and associated safety implications of this mixed fleet, particularly in the training environment. The differences in flight operating characteristics between the governor configurations are significant and could cause confusion and an unsafe condition for students and low-time pilots, especially while operating in adverse flying conditions. Based on these safety concerns, the proposal to install or upgrade, as appropriate, a governor on the Model R22 helicopters is adopted as proposed.

Another commenter, although supportive of the proposal to require a throttle governor, states that installation of a governor caution light should be mandatory to indicate governor failure.

The FAA does not concur. A governor caution light is not necessary since the main rotor RPM gage and low rotor RPM warning horn and light should provide sufficient information to the pilot toindicate that a governor failure has occurred. This suggestion is beyond the scope of the proposal, is unnecessary, and is not adopted.

Operations with the Governor Selected Off

One commenter supports the proposed rule to prohibit flight with the throttle governor selected off, except for system malfunction and emergency procedures training with an instructor pilot. Three commenters oppose this action.

Two commenters state that pilots should be allowed to operate without the throttle governor during all dual training operations with a qualified helicopter flight instructor to ensure the continuing acceptance of the R22 helicopter as a generic piston helicopter trainer.

The FAA does not concur. The FAA considers flight with the governor off to be emergency procedures training and disagrees that the governor should remain off during all flight with a qualified flight instructor to support training for flight in other piston helicopters.

One commenter states thatthe proposed action is too restrictive and may have a negative impact on safety in that it precludes low-time pilots from continuing to reinforce their training through hands-on flying.

The FAA does not concur. The proposed action does not preclude a low time pilot from practicing flight with the governor selected off when that pilot is with an instructor. Therefore, there is still the opportunity to continue to reinforce flight training with the governor selected off.

RFM Changes and Other General Comments

The manufacturer comments that the R22 Rotorcraft Flight Manual (RFM) requires the governor be selected off for autorotations. It further states that a high time experienced pilot should be able to practice autorotations without an instructor.

The FAA concurs. Pilots should be able to reinforce their training by practicing maneuvers in which they have already demonstrated proficiency. Persons who have received an endorsement from a certified flight instructor to act as a pilot in command of a Robinson R22 helicopter should be allowed to practice emergency procedures training without the assistance of a flight instructor. This final rule is revised to require the Flight and Maneuver Limitations section of the R22 RFM to read "Flight prohibited with governor selected off, with exceptions for inflight system malfunction or emergency procedures training."

The manufacturer states that the cost estimate in the proposal is $1,000,000 too high, since only one-half of the 1, 014 helicopters will require the complete governor at a cost of $2,150 per helicopter.

The costs stated in the proposal are estimates. Since it is unknown how many Model R22's will require the upgrade to the throttle/collective governor, there are no data to support a change and therefore the estimated total cost in the proposal will remain unchanged.

The manufacturer also states that the reference to the July 6, 1995 date, the revision date of the Rotorcraft Flight Manual (RFM), in paragraph (d) of the NPRM should be omitted. Additionally, the manufacturer states that the requirement to add page 2-2 to the FAA approved R22 RFM is not appropriate since it is already in the earlier revision to the RFM and is not related to the proposed actions.

The FAA concurs. Changes to page 2-2 of the FAA approved RFM, revised July 6, 1995, do not pertain to the actions of this AD. Therefore, the reference to page 2-2 of the RFM is omitted in this final rule. Also, since the proposal indicated that page 2-7 would be inserted into the RFM, it was necessary to state the revision date, July 6, 1995, of that change. However, this final rule only requires that a specific statement be inserted into the Flight and Maneuver Limitations section of the RFM and not that the manufacturer's specific revised page be inserted into the RFM; hence, the revision date of July 6, 1995 is no longer needed. Therefore, with the exception of omitting the reference to page 2-2 and reorganization of the requirement to add a statement to the Flight and Maneuver Limitations section of the RFM, this action is adopted as proposed.

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rules as proposed except for revisions to paragraph (d) to delete the words "with an instructor pilot" from the requirement "flight prohibited with governor selected off, with exceptions for inflight system malfunction or emergency procedures training with an instructor pilot," deletion of page 2-2 as referenced, and deletion of the reference to page 2-7.

The FAA estimates that 1,014 helicopters of U.S. registry will be affected by this AD, that it will take approximately 8 work hours to install the improved throttle governor, or 7 hours to upgrade the throttle/collective governor, and approximately 0.2 work hour to accomplish the adjustment of the light/warning horn RPM, and that the average labor rate is $60 per work hour. Required parts will cost approximately $2,150 per helicopter to install the improved throttle governor, or approximately $500 for upgrading the throttle/collective governor per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,678,988. This cost estimate assumes that no helicopters are currently equipped with a governor and all will need the improved throttle governor installed.

The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by removing Amendment 39-4645 (48 FR 21894, May 16, 1983), and by adding a new airworthiness directive (AD), Amendment 39-9633, to read as follows:

AD Number	96-11-08	Status	Superseded
Effective Date	July 02, 1996	Issue Date	Not specified
Docket Number	95-SW-27-AD	Amendment	39-9633
Product Type	["Aircraft"]	Product Subtype	["Rotorcraft"]
CFR Part	--- - Part 39 [61 FR 26429 NO. 103 05/28/96]	CFR Section	N/A
Citation	Federal Register: May 28, 1996 (Volume 61, Number 103)

Manufacturer(s)	Robinson Helicopter Company
Model(s)	R22 R22 ALPHA R22 BETA R22 MARINER

AD 96-11-08 SUPERSEDED