# •• (



## I**~** 

### . .**~~·** 

### ..:'-, · ..**,~7**



### U.S. Department ofTransportation, Docket Operations West Building Ground Floor, Room W12-140 1200 New Jersey Avenue, SE

.. Washington, DC 20590 

# Fl3 !

# 0 A c1: ll
14-11.71(a)(1)

Reference

14-11.71(a)(2)

14-11.71(a)(3)

14-11.71(a)(4) Richard Terrill PO Box 2220 Saratoga, CA 95070-0220 richard@rt-aviation.com Doc. No. 18334, 54 FR 34292, Aug. 18, 1989, as amended by Arndt, 91-220, 55 FR 43310, Oct. 26, 1990; Arndt. 91-223, 56 FR 41052, Aug. 16, 1991; Arndt. 91-231, 57 FR 42672, Sept. 15, 1992; Arndt.**91~248;** 61 FR 5F1, Feb. 9, 1996; Arndt. 91-251, 61 FR 34560, July 2, 1996; Arndt. 91-285, 69 FR 77599, Dec. 27, 2004; Arndt. 91-296, 72 FR 31679, June 7, 2007; Arndt. 91-309, 74 FR 42563, Aug.21,2009 Commonly known as: Title 14: Aeronautics and Space Part 91- GENERAL OPERATING RULES Subpart C- Equipment, Instrument and Certificate Requirements § 

### 91.205• Powered civil aircraft with standard category U.S. airworthiness certificates: instrumentandequipmentrequirements. {a){11)- For small civil airplanes certificatedafterMarch 11, 1996, in accordance withpart23 ofthis chapter, an approved aviation red or aviation white anticollision lightsystem. In the eventof failure of any light ofthe anticollision lightsystem, operation ofthe aircraftmay continue to a location where repairs or replacementcan bemade. Reword a potentially ambiguous regulation that has been interpreted in such a way as to ground aircraft that are legally and practically airworthy. The clarification of 91.205(a)(11) will make it explicitly clear that an aircraft only requires a single, fully operational anticollision light system. It would further clarify that failure of a component in an anticollision light system only affects airw01thiness of aircraft with a single anticollision light system installed. Proposed change to the language ofthe regulation Reword this regulation as follows. In practical terms this is only a grammar change, and does not change the intent or safety impact. Bold emphasis shows the additional clarifying text. 

### (a}{11)- Forsmallcivil airplanes certificatedafterMarch 11, 1996, in accordance with part23 · ofthis chapter, an approved aviation red or aviation white anticollision lightsystem. 

### If an aircrafthastwo ormoreanticollision lightsystemsinstalled, onlyoneofthelightsystems mustbe fully operational for theaircrafttobeairworthy. In aircraft with.onlyone anticollision lightsysteminstalled, in the eventof failure of any light ofthe anticollision light system, operation ofthe aircraft maycontinue to a location where repairs or replacement can bemade. Explanation ofthe benefit to public interest This amended regulation will preclude misinterpretation that has lead to unnecessary canceling offlights. This will allow more flight operations in the GA fleet, and also prevent the frustration that results from cancelled practical flight tests due to ambiguous airworthiness criteria. 

### '

# I -' 14-1L71(a)(S) The above-referenced regulation, as written, permits an aircraft to have either a red or a white light system (the key word is "or" in the first sentence). The second sentence, however, has been interpreted by some pilots to mean that ifan aircraft hastwo anticollision lighting systems, and any ofthe lights in either system is not working, then the aircraft is notairworthy. The problem is the 2"dsecond sentence in the regulation with the phrase "failure

### of~ light

..." This issue is the word 'any' may be seen as all-inclusive if "the anticollision light system" is deemed to include all ofthe installed anticollision light systems. A red rotating beacon by itself is sufficient to provide traffic awareness to otheraircraft and ground personnel. A pair ofwhite strobe lights, one each located on the ends ofthe wings is equally sufficient for safety. Ifthe strobes were both working and the red beacon on thetail was notworking, safety is not compromised. Ifthe red beacon is working and one ofthe two strobes is not working, safety is not compromised. This is evidenced by the many aircraft that have only one anticollision light system installed and are operated without collision events. A practical example is the Cessna 172SP, with atype certificate approval of May 1, 1998**(http:fhj__w_w.airiNeb.faa.gov/Regulato_r:_y__anQ__Guidanc~** LibraryL_r:gMakeModel.nsf/0/a9c23e98'!Z**?4~Ji~!3.§257a£~_Q9_?709_?_f/_$._E.!_l,_~/lh1_LI3~!3~_p_Qf.).** This aircraft has both the red rotating beacon and the white strobe lights. Both items are listed as standard ("S") equipment in the Cessna 1725 approved flight manual, so Cessna did not provide more restrictive (than 91.205) equipment requirements. Another example is an older aircraft that did not have strobe lights as afactory option. Ifthey are added afterthe fact through an STC, then some conservative pilots (or examiners) may deem that the intent of 91.205(a)(11) is good and should apply retroactively. Or the STC may be considered to reset the airworthiness date ofthe entire ship to afterthe 1996 cutoff in the regulation. 14-11.71(a)(6) At ourflying club we have one aircraft for which the strobes will not always workon justthe battery power, they require the 14V ofthe alternator. They work fine once the engine is running, but during a preflight inspection they are intermittent. This aircraft has been rejected forflight many times by diligent pilots, when the airplane was in all practical regards airworthy. 14-11.71(b) There is no compliance cost or regulatory burden to operators and pilots. There are no changes to aircraft documentation, operation procedures or checklists. The cost will be limited to the effort required to review, receive comment and modify the regulation. Promulgation will be during the normal course of publishing updated regulations. About Me I hold a commercial instrument airplane pilot certificate, instrument flight instructor certificate, advanced ground instructor certificate. I am an aircraft owner, and chief pilot at aflight school.



### Thank you for considering this request.

P.S. 14-11.63(a)(1) references the URL 

### http://www.{aa.gov/regulations for online submission ofthese requests, but that is not a valid URL.



### cf: Paul King, San Jose FSDO 

# . :•