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### q AIR TRACTOR INC. P. 0. BOX 485 OLNEY, TEXAS 76374 Friday,April29,2016
Docket Operations M-30 US Department ofTransportation 1200 New Jersey Avenue SE 940-564-5616 940-564-5612 (FAX)

Room W12-140, West Building Ground Floor Washington, DC 20590-0001
Docket No.: FAA-2015-1621 Docket Name: Part 23 Reorganization
Mr. Lowell Foster, and the FAA,
We appreciate the intent oftheFAA'sproposed Part 23 Reorganization rules with respect to decreasing the costs ofcertification and enhanced safety. Nevertheless, the rule changes that are proposed are sweeping, affecting Parts 21, 23, 35, 43, 91, 121, and 135, and it is not possible for us to adequately review or address the proposed new rules for their potential impact to our industry (helpful or detrimental), or the general aviation industry as a whole, within the allocated comment period of60 days. Therefore, we request that you please extend the comment period for atleast another 180 days to provide time for adequate technical review and comment,on this complex subject. , The regulations and policies affected by these proposed changes are technical in nature. Therefore, we recommend that comments from the Designated Engineering Representative (DER) communitybepurposefully pursued and collected to the maximum extent possible.
As we have numerous comments to the proposed changes, we offer the following philosophical points as a basis from which a more positive solution-based discussion could begin,based on our : company's more than 50 years ofoperation and cooperation with the FAA in the design, certification, and manufacture ofmore than 3,000 airplanes that are currently operating all around the world. Philosophy: Current Impediments to Rapid and Economical Airplane Certification The primary factors that make the current certification process lengthy and expensive (and frustrating) are
... 1. The time and resources that must be spent negotiating with the FAA to obtain agreement/approval to proceed with certainty;
2. The time and uncertainty that is injected into the middle ofa project while waiting for the FAA to review/evaluate/approve submitted work, before further work canbe accomplished; andApril29, 2016 Part 23 Reorganization FAA-2015-1621
3. The difficulty ofthe qualification process for non-required ornon-safety-related equipment items. page2

The certification process is a gated process. Certain steps must be accomplished before other steps maybe carried out. Inthe current process the FAA controls the gates which allow the applicant to advance to the next step. This gated process is prominent at the beginning ofa project when the Project Specific Certification Plan (PSCP) is submitted. But then later in the project it is typical for the FAA to remain involved at various points in mostpieces ofthe certification effort. That is, there are lots ofgates throughout the overall process in which it is necessary to obtain FAA approval or acceptance. A significant disagreement at any one ofthese points causes the entireproject to stall. In most cases these potential pinch points are not foreseeable at the beginning ofthe project, despite ourbest efforts to plan appropriately when the PSCP is worked out. For example, theFAA typically reserves for itselfthe approval ofaerodynamic loads reports. TheFAA itself generally does not have aerodynamic loads experts on staffat each Aircraft Certification Office (ACO), but there are Designated Engineering Representatives (DERs) available that are experts inthis field, and are generally employed bythe applicant for this type ofwork. Still, the FAA local office holds up the approval ofthese documents until someone at the local officehas reviewed the DER's work. Theresults ofsuch loads definitions efforts are needed before significant structural design, analysis, and approvals can be obtained.
In another example, the FAA typically reserves for itselfthe approval oftestplans. Theproper planning oftests is important for the test results to be valid at the end oftheprocess, butit can delay the downstream test efforts bymonths while the FAA is brought up to speed onthe details ofa project and test, comments on the proposed test are discussed and debated, and the test plan is approved. In almost every case the test plan was already reviewed by a DER (an expert in that field, byjudgment ofthe FAA), who recommended approval ofthe plan, but still the FAA requires that it be involved in reviewing and approving the plan. There is uncertainty on the part ofthe applicant as to whether ornot test fixtures and equipment should be manufactured or procured ifthe test plan has not yet been approved (it could change), so the gated approval process slows the pace ofthe project. Ifthe FAArequires significant changes, theplanning process has to go back and address whatever changes the FAA felt were necessary, then go back through the review and approval process to move on. In one more example, the FAA typically reserves for itselfthe approval ofsystem safety analysis. Theprocess ofsystem safety analysis used in the design and development ofairplanes is complex, with many steps, and each step is subject to a significant degree ofsubjective · appraisal. The original plan to employ such analysis was to aid the designer in the design of systems that addressed the various safetypitfalls within anyparticulardesign, but as currently employed the safety analysis aspects ofa new airplane design typically start before theproject is kicked offand is one ofthe last things to be completedpriorto certification. There is so much required FAA review and approval that there are ample opportunities for disagreements that can delay or stall a project. There are other situations that occurin every airplane certification program which inject uncertainty and time into the process, all ofwhich are due to the need for direct FAA involvement and decision-making during theprocess.April29, 2016 Part 23 Reorganization FAA-2015-1621 page3

Although it has been considered significant that various Light Sport Aircraft (LSA) have achieved certification with rapidityusingASTM F2245 and its other associated standards, we believe that thereal improvement in the process is the minimization ofdirect FAA involvement.
It maybe that some rules should be changed in ways that would bemore ofa common-sense approach. And some rules probably should not be applicable to some kinds ofairplanes. But for the most part, the difficulties that our companyhas had with airplane certification has not been about the burden ofshowingcompliance to unreasonable rules. Rather, itis about the unreasonableness that is associated with the differences between onehuman being and another that represents the FAA. These differences add uncertainty and variance to the overall process, and in the end it takes longer and costs more. This whole rule change movement was originally about trying to reduce the time and expense associated with airplane certification. We completely agree that this is a problem that is critical to ourindustry, and that solving this problem is an objective worthy oftime and effort. But, for the mostpart, webelieve that the proposed rules will increase the time and costs associated with airplane certification.
From the review ofNPRM FAA-2015-1621 that we have conducted so far, we have the following comments. Page references correspond to the 283-page PDF version oftheNPRM that is referenced above. Representation 1. No person from the agricultural aircraft industry was represented onthe ARC (Aviation Rulemaking Committee, seep. 14). With regard to assessing the impact on small firms 

### (p. 173, Chapter VII, Regulatory Notices and Analyses, section B, Initial Regulatory Flexibility Determination, Item 5, Estimated Number ofSmall Firms Potentially Impacted), Air Tractor and Thrush were left out ofthe FAA's analysis. Both ofthese manufacturers use Part 23 as theprimaryportion oftheir certification bases. These manufacturers combined for 182 aircraft deliveries in 2014, totaling over $100 million in sales. Atleast one ofthese manufacturer's has an open project to certify an airplane to the existing Part 23 regulations. 2. Analysis concerningthe impact on small firms (p. 173) ultimately included data from only 5 firms, one ofwhich has not been in operation for 8 years (Adam Aircraft), and another that no longer exists, but is struggling to set up business under new ownership (Sino-Swearingen, then Emivest Aerospace, and now SyberJet). It would seem that the FAA should have knowledge ofevery companythat still has active manufacturing activities (active production certificates), and that the data that was included was exceptionally non-representative ofthe overall industry. Further, by eliminating from consideration all firms that are not US-owned a distorted view ofthe true impact on the general aviation industry in our country is presented.
In addition to American Champion, Maule, and Quest, several small companies that continue inbusiness, and have made aircraft deliveries, were not included inyourApril29, 2016 Part 23 Reorganization FAA-2015-1621 page4

analysis. Among these would be AirTractor (Texas), Angel Aircraft Corporation (Iowa), Cirrus Design (Minnesota), CubCrafters (Washington), Eclipse Aerospace (New Mexico), The King's Engineering Fellowship (Iowa), Mooney (Texas and California), PiperAircraft (Florida), and Thrush (Georgia). There are probablymore. Although some ofthese companies are no longerUS-owned, they all continue to operate within the United States for primary aircraft certification activities, to the certification standards of the United States, and are handled bythe FAA for certification support inthe same manner as anyUS-owned entity. Virtually all ofthem are actively designing new products, ormaking amendments to existing type designs, and therefore have a vested interest in this rule change.
It is noted thatjustbythe inclusion ofonlythe two companies that manufacture restricted category agricultural airplanes (AirTractor and Thrush), both US-owned companies, the number ofemployees and annual revenues represented inyour analysis would be doubled. Itis noted that Cirrus was represented on the ARC, but was excluded with respect to rule impact because ofits foreign ownership. The impact analysis seems to be significantly flawed.
3. A review oftheFAA's list ofType Certificate Data Sheets shows that there are hundreds or thousands ofTC Holders for Small Airplane products. Whether ornot these type designs are being actively manufactured, theymust still be supported bythe TC Holder. The scope ofaffected small businesses was not adequately addressed.
4. There are a large number ofSTC Holders that certifyproducts to the Part 23 rules, and are active manufacturers. The effect on these companies was not considered inyour analysis. 5. Itis noted that Tamarack Aerospace, who was represented onthe ARC (seep. 14), and who is in the business ofdesigning and certifying load alleviation devices, has secured accommodation for devices oftheir type in the regulations (see proposed §23.305). Considerable space was afforded in the discussion (pp. 81-84) to lobby for the inclusion ofsuch devices in a manner that maximizes theirutilityto the industry. We do not oppose the inclusion ofsuch devices, but it would appear that havinghad representation onthe ARC mayhave afforded directbenefit to its participants. Conversely, lack of representation mayprove detrimental for our company. 6. The effects on the certification ofrestricted category aircraft were not addressed and no workhas been done to establish an appropriate means ofcompliance standard. Today most agricultural or otherrestricted category airplanes are certified to the rules ofPart 23, with certain rules deemed not applicable per AC 21.25-1. 14 CFR §21.25 establishes the restricted category, but ourindustry continues to rely heavily on Part 23 to establish certification requirements. Is there still a home for restricted category aircraft under the proposed Part 23?April29, 2016

General Comments Part 23 Reorganization FAA-2015-1621 pageS

1. With respect, we find the following FAA comment (from the top ofp. 10) regarding costbenefit analysis to be vacuous: "Ifthe proposed rule saves only one human life, for example, by improving stall characteristics and stall warnings, that alone wouldresult in benefits outweighing the costs." Bythe standards ofthat statement the cost-benefit balance for outlawing all forms of motor vehicles (and bicycles, and skateboards) would bejustified.
Webelieve that ourindustryplaces a very high value on protectinghuman life, and expends enormous energy, talent, and resources to protect it. In thepastthe regulatory environmenthas made itdifficult to implementinnovative solutions, wherein the FAA certificationprocess was the impediment to progress (not necessarily the rules). The FAA needs to understand that mandating the changes that are contained in these proposed rules (such as departureresistance) generally will not help applicants achieve certification; they will instead make itmore difficult to obtain certification, and thereby impede the development and certification ofnew airplanes with these favorable characteristics.
2. Itis recommended that all references to alternate metric units be removed. Their existence opens the door to misinterpretations about precedence when the alternate value shown is not an exact conversion (and it almost never is). For example, takeoff performance data per §23.115(b) to an altitude of50 feet (15 meters). Use ofan exact 15-meterheight would round to 49 feet.
3. We don't see a bigdifference in the certification effort required for the different Levels and Speed classes. Maybe there is a big difference in required levels ofsafety for equipment, but that is impossible to tell because the FAA has not decided what those levels ofsafety will be (see proposed §23.1300).
It should be noted that the preamble material accompanying these proposed rules will not be given the weight oflaw. Uncodified good intentions stated in the preamble are ofno lasting value.
4. The new certification process will create a "hidden certification basis" for TC'dproducts, composed ofthe regulations and the means ofcompliance. A person who did not participate inthe certificationprocess will not know how that aircraft was certified, because those certification requirements that were previously disclosed inthe prescriptive regulations will now behidden behind private negotiations with the FAA in the means of compliance agreements. Imagine trying to obtain an STC for a TC'd product without knowing what maneuvering or gust load factors were deemed necessary for the product during its initial certification.
Itmaybe that the would-be STC holderhas no rightto know that information, buthiding such information will tend to stifle the approval ofSTCs apart from a cooperative TC holder, and thereby it will slow the approval ofthird-party STCs from whichmost electronics and safety-related innovationhas come.April29, 2016 Part 23 Reorganization FAA-2015-1621 page6

5. On p. 39 (lastparagraph) it says theproposed changes to 14 CFR §21.9 will allow manufacturers ofreplacement ormodification articles ofnon-required safety-enhancing equipment (whose failure would not cause a hazard) to obtain production approval from the FAAwithout obtaining an FAA design approval for that equipment. Historically, this emphasis offast-tracking non-required safety-enhancing equipment approvals has not applied to OEMs that want to install the same equipment. Will theproposed changes to §21.9 apply equally to a TCholder that wants to install this type ofequipment without design approval for the equipment? We believe that STC applicants and TC applicants should be treated equally.
Consensus Standards 1. We do not agree with the proposition that removing the prescriptive regulations will make for a simplified certification process (reference p. 20, the lastparagraph ofChapter III, Section C). For standard configuration aircraft, the prescriptive regulations are the simplestregulations to meetbecause there is a definite pass/fail criteria. Itis the vague and general regulations that are more often the regulations that require complex FAA involvement because there is no agreement on what the pass/fail criteriais.
2. Removing theprescriptive regulations is going to allow for much wider disparities concerning what is an acceptable showing ofcompliance. Some applicants will beheld to high standards, while others will berequired to meet a lesser standard, because ofthe combination of

... a) Whatthe applicant proposed; and b) What FAA local personnel felt was necessary. Both ofthe above are significant variables. Theformer depends significantly on the applicant's knowledge, sense ofprevailing expectations, and negotiating skills. The later depends on the reasonableness andknowledge ofthe specific FAApersonnel that are involved.
For airplanes ofstandard design the existing rules are generally adequate. When there are non-standard design features, orthe rules are deemed inadequate orinappropriate, our existing system has a means ofaddressing such things through the issuepaperprocess. This is a slow, tedious process that should rightly be avoided. Yet it would seem that the proposedplan to rely on consensus standards for showing compliance to mostrules will require the Applicant and the FAAreach an agreement on an acceptable means of compliance for every rule, even for airplanes ofstandard design. From page 24, the last sentence ofparagraph 1, "Theprocess for reviewing new means ofcompliance would not change substantially from the process inplace today." This has the potential to function like havinghundreds of"mini issue papers" for everynewproject.
Webelieve that the FAA alreadyknows about, and appreciates, the extra delay and drag thatwill be incurred duringthe process ofnegotiating a PSCP for a newproject, but under themandate from Congress to reduce the time and costto certification is willing to allow the prevailing optimistic philosophyto playout to reality. In the discussion for §23.10 regarding "Accepted Means ofCompliance" onp. 51, the FAA felt compelled to warn,April29,2016 Part 23 Reorganization FAA-2015-1621 page?

"Additionally, the FAAwants to ensure applicants understand that an applicantdeveloped means ofcompliance document would require FAAreview and acceptance by the Administrator."
For a sense ofhowtedious and obstructive this process can be, our company proposed a new airplane design to the FAA in October 2002, for which a G-1 issue paper was written to establish the certificationbasis. This issue paper was not completed until May 2010 7ih years! Even then, a smaller issue regarding compliance to three Part 23 rules needed to be worked out in an A-1 issue paperthat took another 2 years to resolve. This process ofrecorded back-and-forthbetween the Applicant and the FAA showed us that the FAA does not always have a good understanding ofits own rules orthe expertise at the local level to work out reasonable means ofshowing compliance. Ittook a lot ofnegotiating to work outrules that were even somewhatreasonable. When this negotiation occurs project-by-projectthe results will behighly variable, consume enormous time and resources from both the FAA and the Applicant, and make it impossible to design a new airplane with knowledge ofwhat is expected for certification. (Most airplanes are designed to a significant degree before their certifications are proposed to the FAA.)
Ifthese negotiations are handled by a single group ofpeople at the FAA there will likely be more parity between projects, but now there will be a bottleneck in theprocess as every company inthe countryneeds to negotiate through this one group. Wehave heard that ASTM standards, as well as some other standards, are going to be acceptable means ofshowing compliance. The assumption seems to be that the FAA will publish the list ofaccepted standards and that, as policy, FAA certification specialists should accept these standards without question. Butwe do not see a clearplan to implementthis as regulation orpolicy. We expect that during the negotiation process to set the certification basis for a product that each specific MOC that is proposed bythe applicant will need to be reviewed by the FAA local office to determine ifitis appropriate for the proposed product. Even ifthe applicant elects to usepieces ofFAAaccepted ASTM standards for everyproposed MOC, this review process will take more time, not less.
For aircraft ofnon-standard configuration that would already be subject to the issue paperprocess
- the new process maynotbe much different, even ifincreased flexibility is available. But most aircraft are not that unusual. Under the new process, for aircraft of standard configuration it will take almost as long to hammer out a certification basis as would be needed for an existing airplane ofnon-standard configuration. This doesn't seem like progress. The most time-consuming and frustrating aspect ofcertifying a new airplane is establishing the certification basis and obtaining approval ofthe PSCP (project specific certification plan). Ordinarily this is a negotiation between the applicant and the FAA for everyproject, which can last from several months to several years. Underthe new rules virtually everyrule will require that the language for the means ofcompliance must now benegotiated, which will increase the effort that is necessary to obtain an approved PSCPApril29,2016 Part 23 Reorganization FAA-2015-1621 pageS

by an orderofmagnitude. This is not movingin the right direction for most airplane certification efforts.
3. The FAA says on pp. 24 and 52 that switching to consensus standards would notbe biased in favor ofthe largermanufactures. We think that the largermanufacturers will have the manpowerto assign permanent personnel to work on developing standards with the ASTM while the smallermanufacturers do not have the resources ormanpowerto assign someone full-time to represent their interests in ASTM standard-writing activities.
4. The consolidation ofconsensus standards within the ASTM imposes an economic barrier for smaller companies. This move takes the currentprescriptive regulations, which are presentlyopen and free for any individual to view, and moves them to a hidden "pay for access" location. An example ofsimilarprivatization ofstandards was the move from MIL-HDBK-5 to MMPDS (Metallic Materials Properties Development and Standardization). This document is referenced injustabout every aircraft structural analysis everwritten. MILHDBK-5 was a government issued document, paid for byUS tax dollars, with free access to all interested parties. When this critical information was transferred to Battelle to serve as the custodian, only the first version (MMPDS-01) was free. Ifyou want to purchase a copy now (at MMPDS-09) you need to pay $679 for an electronic version, or $809 for a paper copy. Itprobably should bejust a cost ofdoingbusiness to buythe latest revision every couple ofyears or so, but a lot ofsmall companiesjustkeep referencing MMPDS-01, because it's what they can get. This seems to be the direction that this change is going, except with a lot ofcritical documents. It is not very difficult to imaginehow this change will save the FAA the expense ofmaintaining documents that are critical pieces ofthe certification process, but it is difficult to see how this change will do anythingbutincrease the costs ofcertification that must be bornebythe applicant. This new economicbarrier also removes transparency from the certification process, makingit difficult for the smaller company to evenknow what standards are available without purchasing all ofthem. Effectively, these new ASTM standards become rules that mustbe followed in order to show compliance to the proposed Part 23 rules. The FAA has stated that these will not be the only accepted means ofcompliance (just one accepted means), but to achieve FAA acceptance ofany other means ofcompliance will require a huge investment oftime and money- an undueburden for most small companies. (How is this going to save the applicant time and money?) It is apparent that for some significantperiod oftime the ASTM standards that are in work will bethe onlyrules available that are FAA accepted. Therefore, in the interest oftransparencyregarding the actual certification process (apart ofwhich will be veiled behind a pay-per-view barrier), and in the interest ofreducing the costs associated with achieving certification, wethink that the US government should be required to make all FAA-accepted consensus standards available to thepublic, free of charge, as is done with Advisory Circulars.April29, 2016 Part 23 Reorganization FAA-2015-1621
Are the proposed changes to the rule& supposed to be about reducing the costs of certification for the applicant, oronly for the FAA? page9

5. Itis likelythat larger companies with more sophisticated processes, and personnel that are dedicated to perform certain functions, will choose to develop their own applicantbased means ofcompliance. This will enable them to tailor the process ofshowing compliance to theparticularneeds orapproaches developed bytheir company, orthe airplane project in question. They will develop their own logic and rationale, based on negotiated interpretations ofthe words in the rules. But when this is done there is no incentive for them to work through the ASTM orotherpublically-accessible holders of consensus standards. They won'tneed the expertise ofthe ASTM, and why should they spend theirmoney to help other companies (including their competitors) have access to FAA-accepted means ofcompliance? They will considerthose FAA-accepted means of compliance documents to beproprietaryintellectual property. There is even thepossibility that portions ofthese documents could bepatented as a process, therebypreventing their competitors from using that process without proper licensing, which they would not allow.
We feel that the cause ofairplane certification for smaller companies, or start-up companies, will notbe advanced under this process. The barfor entry into this industry will beraised, making it more difficult to get started. Or, as the existing regulations are transferred into an ASTM specification that is FAA-approved as an accepted means of compliance, at a minimum the requisite effort will beno less than before.
6. It appears that ifthe actual wording ofPart 23 were to never change again, the rules of certification would continue to move. Consensus standards would continue to change without the benefit ofan NPRM to allow applicant review ofnew versions ofstandards. Itis unclear whetherthe FAA would continue to allow the use ofASTM standard :XXXX Revision A whenthe current released version has advanced to Revision F, butwe expect that it would not. They would probably say that you could propose it, but how would that be different than for today's process for asking to use an old amendment level for Part 23? Therefore, the barwould continue to move without recourse for the concerns of others that do not have input into the process. For example, can the ASTM decide that an earlier version ofan FAA-accepted standard has a shortcoming and put a clause in the new version saying earlier versions are hereby cancelled and are no longer acceptable for new design? Can wording like "this standard mustbe used in its entirety" bewritten into a consensus standard and ithave legal meaning? Rule Organization 1. None ofthe current Part 23 rule numbers remain the same except for §§23.1, 23.1457, and 23.1459- all other rule numbers have been changed. Although the present Part 23 rules will remain available (most ofthem) as acceptable interpretations ofcompliance for the proposed rules, because the proposed rules are not organized within the existing structural outline for content itwill not bepossible to list the old and the proposed rules together in numerical sequence without mixingup the rule topics.April29, 2016 Part 23 Reorganization FAA-2015-1621 page 10

2. Several existingrule numbers have been overwrittenbyproposed rules that no longer contain content pertinent to the existingrule. This will make it extraordinarily complex to reference the oldrules from a certification basis that is based on the proposed rules. This would be especially difficult if 14 CFR §21.101 is used to voluntarily certify some design change to one ofthe newly proposed rules withoutbeingrequired to change the certificationbasis regarding compliance to the old rule that had the same number. Potentially, a single certification basis could employ two completely differentrules that have the same number, but at different amendment levels, and both ondifferent subjects.
Rule numbers that have been "repurposed" for proposed rules ofcontent that is dissimilar to the rules that currently inhabitthoserule numbers are: §§23.305, 23.405, 23.505, 23.755, 23.905, 23.925,23.1310,23.1325,23.1335, and all ofAppendix A. This also applies significantly to §23.1305, which has only partially continued pertinence. Only one "repurposed" rule number, although changed, seems to have maintained its original contentpurpose: §23.1505. Appendix A to Part 23: This appendix (instructions for continued airworthiness) would over-write an existing appendix having a different purpose (simplified design load criteria) that was likely necessary for the certification ofsome earlier airplane. 

### It would seem unwise to do this, as it would be confusing to identifyrules having identical appendix rule numbers onlybythe era ofthe document (amendment level).
We suggest that proposed Appendix A should remain Appendix G.
3. Please consider callingthe proposed rules Part 22, or some otherpart, to ensure a clear distinction between the existingrules to date and theproposed rules. Historically, this was done when the CARs became theparts of 14 CFRthat we have today, which has helped to minimize confusion when referencing these predecessorregulations. We believe that the sweeping changes that are proposed deserve their own Part. Itwill soon become extraordinarily confusing to referto the old and new sections ofPart 23. The existing Part 23 must continue to exist1

, as it is the certification basis for most existing airplanes, and (per §21.101) will continue to be the certification basis for most amended TCs and STCs on those aircraft for many decades. In some ways the old rules will become obsolete like earlier amendments ofexisting Part 23, orthe CARs, which are inactive rules for new design, but valid for products for which they are the existing certificationbasis. Yetin other ways they all turn into advisory circulars, orpublicly accessible consensus standards, that are considered one acceptable interpretation of compliancel. And perthe discussion on p.162 (the last sentence in Item 6) regarding 14 CFR §21.101, the changed product rule,

1 Seep. 79, the first paragraph, and the last sentence, "Applicants would need to substantiate the level ofsafety for proposed means ofcompliance that deviate from the prescriptive regulations." 2 See p. 110, second paragraph, last sentence: "TheFAAexpects the current means ofcompliance would continue to be used for the traditional airplane designs under part 23."April29,2016 Part 23 Reorganization FAA-2015-1621 page 11

"This current provision would allow for compliance to the certification requirements at amendment 23-62 or earlier when compliance to the latest amendment ofpart 23 was determined by theFAA to be impractical." It would seem that almost any existingrule may form a portion ofthe certification basis for new airplanes for a long time to come. 4. Please consider calling the proposed rules Part 22 (or some otherpart number) and giving the Applicant the option ofcertifyingto Part 22 orthe existing Part 23.
Ifthe adoption ofthese rules will really reduce thetime and cost to achieve certification, the industry will choose Part 22 overPart 23. Or, ifindustry determines that these changes do not streamline the certification process, they will reject it and may continue to use the existing Part 23. There is significant risk (we feel a high probability) that the proposed changes will be determined to be detrimental to the Congress' stated objective, and we should not commit to the irreversible dismantling ofthe world's gold-standard for aircraft certification inpursuit ofa process thathas not been verified to be a success. 5. What is the FAA's plan concerning existing guidancematerial that references the Part 23 regulations by specific number? This affects a large number ofAdvisory Circulars (e.g. 21.25-1, 23-16, 23-17, 23-19, etc.) All ofthese ACs will be out ofdate when these new regulations are issued. Rule-specific Comments 1. 23.1: When there is only one category, and it is called "Normal", what is the point of usingthe term "category"?
The definition ofthe term "EmptyWeight" could use some clarification. Specifically, this weight does not include fuel that maybe consumed, butthepresent wording, "full operating fluids, and otherfluids required for normal operation ofthe airplane systems", might reasonably be interpreted to include fuel.
Wepropose that a definition beprovided for the "Minimum Flying Weight" for use with a revised wording to §23.300(c)(l). There is no pointto certifyingthat a structure is safe for operations below any weight atwhich it can be operated. The Minimum Flying Weight would include the weight ofthe pilot (ornecessary crew) and the minimum fuel required for legal operation for the lightest equipped airplane that complies with type design requirements.
2. 23.5(a): Whyis there a 19,000-lbupper limit concerningrule applicability? What is the basis for establishing this upper limit? Where does the 19,000-lb limit come from oris it just an arbitrary number? Throughout the preamble the FAA states that they realize that differentiating certification by weight categories was inappropriate and did not achieve the desired result. Whythen arbitrarily attach an upper weight limit to these regulations? This seems to be an inconsistent approach when the FAA has worked so hard onthis proposal to eliminate weight categories.April 29, 2016 Part 23 Reorganization FAA-2015-1621 page 12

We feel that it would be more consistent to differentiate by §23.5 Level and Speed categories only. There doesn't seem to be a basis for weight differentiation on the FAA's safety continuum. Itis imagined that there maybe some 

### "turfwars" regarding business jetsthat exceed 19,000 lb, but would otherwise fall well within the 19-passenger limit, that are currently regulated within the domain of 14 CFR Part 25. But is there any reason that this should remain? Itwould seem that the applicant should be free to decide ifthe greaterrigor ofPart 25 would be deemed an asset by their customers that is worthy ofthe extra certification expense. Airplanes have always followed propulsion technologies. In particular, airplanes are sized bythe availability ofpowerplant choices. There was a time when no one would have envisioned that an 800,000-lb airplane could bepowered byjusttwo engines, but the availability ofsuch engines made those airplanes a reality. Similarly, the prospect of a single-engine airplane that exceeds 19,000 lb is not far off.
So what is to be done with a single-engine airplane that exceeds 19,000 lb, but carries 0 to 1 passengers? Existingregulations have no home for this type ofairplane -noteven this proposed rule that seems to be questioning most ofthe arbitrary limits. Again, the 19,000-lb upper limit seems arbitrary, and technologicallylimiting.
This comment also applies to §21.35(b)(2) regarding function and reliability testing. Whyis there an arbitrary 6,000 lb weight limit to the exemption from this type oftesting?
We would propose that this be resolved byeliminatingthe need for function and reliability testing altogether. Themarket will sort out function and reliabilityissues by means ofnatural economic controls -theFAA should have no part in this.
3. 23.5(c): The insertion ofthe MMo limits inparentheses is confusing. Itis not clear if these values represent new absolute constraints, or ifthey were intended to provide an approximate context for what 250 KCAS mightmean at somehigher altitude.
As it happens, Mach 0.6 corresponds to 250 KCAS at about 23,400 ft in a standard atmosphere, but whatperformance level would be assigned to an airplane with a Vc = 250 kcas and an MMo = 0.65?
4. 23.10 Accepted Means ofCompliance: This new rule specificallymentions consensus standards, but then shouldn't this section also mention FAA Advisory Circulars as accepted means ofcompliance? The use of Advisory Circulars is almost completely ignored in this NPRM. This new rule seems to bemostly procedural, and is unnecessarily constraining. Whatis the intention ofrequiring by new rule that all means ofcompliance mustbe FAA accepted? Has there ever been a c"ase where an applicant successfully showed compliance (and receivedtype certification) by somemeans ofcompliance in which the FAA disapproved? There are alreadyFAA Orders which describe theprocedural details ofthe FAA certification process and discuss the setting ofexpectations regarding FAA acceptance ofcertification plans, test plans, and the like. So what failure ofthe existing system led to the creation ofthis new rule?Apri129, 2016 Part 23 Reorganization FAA-2015·1621 page 13

The existingrules are generally silent onthe means ofcompliance for most rules, butthis has notprevented airplanes from being certified. Where ithas been important to specify a particular means ofcompliance [Ref. §§23.307(b), 23.471 (f), 23.641, 23.683, 23.723(a), 23.725, etc.] ithas been speCified. When a particularmeans ofcompliance is not specified the applicanthas always been free to propose a suitable means ofshowing compliance. So what is gained bywritingthis down as a new rule? Itis not clear ifthe need to obtain FAA approval for each means ofshowing compliance is intended to apply at the beginning ofthe process (when the certification plan is negotiated) orjust sometimepriorto showing compliance. DraftAC 23.10, Section 5.2, seems to suggest thatthese MOCs will need to be included in the project specific certificationplan (PSCP).
What will be the role ofDERs, ifany, in finding compliance to proposed §23.10? Will compliance to this rule always be a retained finding for the FAA?
In the past PSCPs and Compliance Checklists have been administrative documents that were about ensuringunderstanding between the applicant and the FAA, and for the administrative purpose oftracking theproject to completion, but were not used to show compliance with anyrule. Itwould now seem that FAA approval ofan applicant's proposed means ofcompliance- normally contained within the compliance checklistwill become a substantiating document, a documentthat isused to show compliance with §23.10. Establishing an acceptable means ofshowing compliance duringtheprocess of negotiating the PSCP should be limited to picking one ormore ofthe following: Analysis, Tests, Design Review, Physical Inspection, etc. The details ofthe means of compliance for tests maybe covered in a test plan that theAdministratorwill approve, but for analytical methods, design reviews, orphysical inspections this generally would not betrue, and would add a new bureaucratic step in the process. AnyASTM type ofconsensus standard used to establish a means ofcompliance (such as therestatement ofthe existing Part 23 rules) would not be sufficiently detailed to function as a test plan, so obtaining FAA acceptance ofa means ofcomplianceby use ofthe previous prescriptive rules will nottake the place ofdetailed test plans, they will be additional non-value-added (relative to the prescriptive rules) documents and approvals. It sounds like this rule would require the FAA to review and approve ofparticular methods ofanalysis (classical vs. finite element, for example) before the analysis canbe presented. Thisrequirement would benew for mostrules, and would require a new level ofrequired response from the FAA that would drastically slow theprocess ofeither establishing the certification plan or showing compliance.
Oftentimes the details ofan airplane design (especially systems) are incomplete at the time that application for certification is made. Therefore, it is not always possible for the applicant to determine what means ofcompliance will be employed when the certification plan is worked out. At a minimum, it would benecessary for the FAAto acceptbroad, general statements from the applicant when the certification plan is workedApril 29, 2016 Part 23 Reorganization FAA-20 15-1621 page 14

out, and then move to specific means ofcompliance as the detailed design is completed and the need to show compliance approaches. But obtainingpre-approval is still an extra step for mostrules.
Inmost cases when compliance is shown by analysis a DER is authorized to approve that analysis directly, without further involvement by direct FAA personnel. It appears that this rule would re-insert the FAA into the approval process by requiring advanced approval ofthe analytical methods that are employed.
How does this new requirement square with the FAA and Industry Guide to Product Certification? Is that document still valid?
5. 23.215(b), Stall characteristics, stall warning, and spins: "Levels 1 and 2 airplanes and level 3 single-engine airplanes, not certified for aerobatics, must nothave a tendency to inadvertently depart controlled flight."
There is no explanation in the new regulations about what itmeans to "nothave a tendency to inadvertently depart controlled flight", but we can imagine that it will be difficult to prove an aircraft meets this requirement! One worrisome thing is the wording in Item 2 onp. 9: "Theproposed revisions would REQUIRE applicants to use new design approaches and technologies to improve airplane stall characteristics and pilot situational awareness to prevent such accidents."
It might seem possible that showing compliance to this regulation could be as simple as showing compliance to the current regulations (§§23.201, 23.203, 23.207, and 23.221), but perthe first sentence ofp. 28 this won't work. We won't know what this means until the ASTM specs are issued and approved bythe FAA. Our companymayhave problems complying with the intent ofthis revised regulation. Our airplanes are designed to operate and maneuver closeto the ground, and sometimes close to the stall. Adding some kind of"substantial departure resistance to prevent inadvertent stalls from resultingin a departure from controlled flight" (see the first paragraph ofp. 70) has thepotential to significantly increase pilot fatigue. Ifthe control forces are significantly increased as the stalling speed is approached, pilots flying agricultural or firefighting airplanes will be forced to work against these barriers constantly in an already physically demanding environment, potentially decreasing safety by adding to pilot fatigue and reducing maneuverability.
6. 23.300(a)(1): The establishment ofVA, the design maneuvering speed, should be clarified to prevent the possible misinterpretationthat this rule defines thepurpose ofthe design maneuvering speed, and to ensure that it applies at the design maximum weight. We would propose slight rewording, as follows:
The design maneuvering speed, VA, :whieh maybe no less than the airspeed at which the airplane will stall at [themaximum design weight and] maximum design maneuvering load factor;April29, 2016 Part 23 Reorganization FAA-2015-1621 page 15

The word "which" has been deleted, to avoid misleading the reader to misunderstand that the words that follow are the definition ofV A· In most airplanes the design maneuvering speed roughly correlates to the stalling speed at the design maneuvering load factor at the design maximum weight (VA is defined in §23.335(c)(l) as Vsfn), but itis not exactly that, nor is the purpose ofthis airspeed intended to protectthe overall structure from pilot-induced overloads. When the airplane is flown at this airspeed, but at reduced weight, it is possible to exceed the design maneuvering load factor without stalling. When this is done the flight surfaces may not be overloaded, but the increased load factors will increase the loads on structures that support items offixed mass (such as engines, landing gear, cargo, etc.), and these loads may even exceed those that occur at critical gust load factors. Therefore it is critical that VA notbe viewed as an airspeed limit that will prevent inadvertentpilot-induced overloads. Under the current regulations the pilot is advised ofthe need to reduce the speed at which abrupt control movements are made at reduced weights via the maximum operating maneuvering speed (Vo) established per §23.1507. This speed is reduced as a function of the operating weight.
The true purpose ofVA is a design airspeed that limits the structural loads that maybe applied to the flight control surfaces. IfV Awere trulybeing defined bythe wording that was proposed it would be at odds with the purpose that itis defmed for all other airplane certifications, and with otherpublished discussions about its use. Itis noted that there is no longer any method for reducing Vc to (0.9)VH. This will be a loss for airplanes that are exceptionally draggy (such as agricultural airplanes equipped with spray equipment), as they will berequired to be designed for loads that are beyond what they may experience under normal operations, thereby adding otherwise unnecessary structural weight, and reducing thepayload that maybe carried.
7. 23.300(b): Our company has had bad experiences3 when the FAA is tasked with establishing design maneuvering load factors without regard for the prescriptive formula established by §23.337(a). Ifyou have an unusual airplane design situation, there will be a protracted battle for any applicant to work outreasonable load factors underthe new rule. 8. 23.300(c)(l): The proposed inertia envelope covers weights from "emptyweight to maximum weight". Itis recommended that this range be changed to the "minimum flying weight to maximum weight". As defined throughout the regulations, the empty weight is applicable to a particular aircraft and includes the particular set ofoptions installed when that aircraft is manufactured. The term "minimum flying weight" {see comment for §23.1) would be more appropriate for aircraft certificationbecause it is not specific to a certain aircraft serial number and there would beno confusion between operational and certification

3 See the discussionregarding Issue Papers at the end ofp. 6.April 29, 2016 Part 23 Reorganization FAA-2015-1621 page 16

requirements. Seethe existing §23.25(b). We believe the actual intent ofthis regulation is to define the minimumpossible weight for certificationpurposes. Werecommend that you add a definition ofthe term "minimum flying weight" to the proposed §23.1(b).
9. 23.310(c): Formost new airplanes there is no "servicehistory". There is dangerhere that the FAA will require that "servicehistory" be collected before certification is granted for a new design. We recommend that the "service history" clause be deleted.
10. 23.315(a): Are the gust velocities from existing Part 23 or CAR 3 based onmeasured gust statistics? Maybe they are, but we've never seen that technical report. These values are quite different between Part 23 (from Arndt 23-7 on) and CAR 3. Would CAR 3 values be sufficient? Who's to say that the existing Part 23 values will be deemed sufficient?
The freedom that seems to be afforded here to "makeup your own requirements" should be viewed through the lens ofworking with a potentiallyuncooperative FAA counterpart. We'd all like to think that won'thappen, but most ofus have (on occasion) experienced that reality. The FAA also warns at the top ofp. 86, "Applicants who wish to propose alternate design loading conditions should note that extensive data collection, testing, and evaluationmaybe necessaryto substantiate their proposaL" 11. 23.320: Are the "groundhandling conditions" from (a) different from the "jacking and towing conditions" of(c)? Ifso, what does it mean? Are we talking about protection from "hangarrash"? Do we now need to define the structural loads associated with docking an airplane, or from wave motion causing scuffing where a seaplane is moored against a dock?
12. 23.405(d): Inthe existing regulations [§23.903(b)(1)].the effects ofa rotorburst are subject to a minimizationrule. That is, there may be somepiece ofstructure whose damage from a fragment would be catastrophic, but it is so small and positioned at such a distance from the rotor that the probabilitythat a fragment will hit it is so remote that the risk is acceptable. Itappears that this type ofrisk is no longer acceptable, and that redundant load paths will berequired for all principal elements within a rotorburst zone. 13. 23.41O(a)(l): "At all speeds within and sufficiently beyond the structural design envelope." What is "sufficientlybeyond"? The current regulations do not extend beyond the design envelope, although advisory material suggests evaluatingtheresponse for some distance outside ofthe approved envelope. But this new regulation will require that the structure be approved as free of flutter "sufficientlybeyond the structural design envelope." Will it now become prudent to evaluate theresponse some distancebeyond the point that is determined to be "sufficiently beyond the structural design envelope?"
14. 23.500(b): Therequirement that the design data must "adequately defme" the design is a welcome addition. This rule will add specificity to the existingrules for type designApril 29, 2016 Part 23 Reorganization FAA-2015-1621 page 17

(which presentlyreside in 14 CFR §21.31) in a location that maybe addressed byDERs during the review and approval oftype design drawings. (Compliance to Part 21 rules may not be found byDERs.)
15. 23.500(d): Werecommend thatthe FAA revise the wording ofthis regulation to specify that it applies to flight controls.
Itwould seem that the definition of"maximumpilot effort" has also been untethered from the existing definition afforded in §§23.397(b) or23.143(c). Itwill now be necessary for every applicant to re-invent the wheel.
16. 23.515(b): The existing regulation [§23.619(c)] addresses "uncertainties in manufacturingprocesses or inspection methods", as a general or global consideration. The new proposed regulation is worded such that the special factor must account for "each inspection method", making it specific to the inspection method, whether or not it is critical. Inspection methods are generally not defined in an approved type design unless they are critical.
The new wording goes on to include structural test requirements, sampling percentage, and process and material controls. Those considerations would be defined in a quality system that is approved under a production certificate, but would not be defined in the type design. A type certificate is a transferrable commodity (see 14 CFR §21.47), whereas a production certificate or an approved quality system are not transferrable (see §21.144). Therefore, it is necessary that a type design (which is the object ofa type certificate) be approved independently ofany quality system orproduction system requirements. Although most ofthenew rules are worded more generallythan the existing rules, this is a case where the new proposed rule has added unwarranted specificity. The general wording in §23.619(c) is preferable. 17. 23.600(a): It seems that we should expect future certification efforts to require more effort (and possibly full-scale crash testing ofthe fuselage) to meet these requirements. This rule does not specifically saythis, but thepreamble (Item 1 on p. 8) seems to allude to it. The "inertial loads likely to occur in an emergency landing" are now undefined, left to a yet undetermined consensus standard for definition. Itis presumed that the conditions defined in the existing §23.561 would be accepted, but doing that won't be any easier or faster orless expensive underthis new rule. Should some other "inertial loads likelyto occur in an emergency landing" beproposed the applicant should expect a protracted discussion with the FAA to defend any differences. Regarding the wording of(a)(l), we suggest rewording as follows: "Properlyusing safety equipment and features provided 

### ffif inthe design." That is, delete the word "for".
18. 23.600(d): There are an awful lot ofrequirements in this one requirement. We'd suggest that you break itup into parts.April29, 2016 Part 23 Reorganization FAA-2015-1621 page 18

19. 23.700(a): This regulation would require safety analysis for all flight control systems in order to properly classify any failures as major, hazardous, or catastrophic. Such analysis is appropriate for certain kinds offlight controls systems, such as powered or automatic flight control systems, but is not appropriate for simplemechanical flight control systems (cables, pulleys, chains, etc.). Historically, theprecept ofstructural integrity- or structural soundness- has not been subjected to the skepticism ofthe system safety specialists and their probabilistic numerations. This new rule will add cost and complexity for thevast majority ofnew projects, most ofwhich will not be "fly-by-wire", Bluetooth-integrated, autonomous flight-capable vehicles. · 20. 23.700(b)(3): The wordinghas changed compared to the current Part 23 rule. Currently this only applies to longitudinal controls. Theproposed rule would seem to apply to all three axes ofthe flight controls. We do not see how most airplanes will be able to handle the failure ofa singlepushrod on one aileron (which will progressively float upward during the landing flair), or how you can land a tailwheel airplane safely without directional control. For airplanes without 3-axis trim it maynot bepossible to certify. Or, this rule may drive redundant flight control surface interconnections (ala Ercoupe), which maybe "safe", but generally undesirable.
We are not aware that the loss ofprimary controls due to any single failure in the control system (apart from human errors inmaintenance) is a significant problem in this industry that needs to be fixed. Wewould recommend a return to the original wording ofthis rule.
21. 23.700(d): New increased complexity.
22. 23.810(b): "Airplanes approved only for visual flight rules must achieve lightning protection by following FAA accepted design practices." This regulation is extremely vague. Its wording doesn't even give an idea ofwhat the level oflightning safety is. It offers no real performance standard, nor any means ofcompliance. Effectively, this regulation makes all ofthose "FAA accepted designpractices" (read Advisory Circulars) required and regulatory. 23. 23.900(c): Inplace ofthe words "mustbe type certificated" we would suggest you use "mustbe type certified", or "must possess a type certificate." This comment applies to §23.905(a), too. The proposed rule is supposed to better support the new wave ofmodem airplanes, such as those with electric motors, orthermonuclear steam engines, or whatever "otherpower sources not yet envisioned"4 may come along. But a type certificate on those powerplants will still berequired. Is this new rule really going to help those folks? It would seem that eitherPart 33 would need to go through its own drastic changes (and be retitled "Aircraft Powerplant Units"), ornew regulatory Parts would need to be authored to cover each one ofthese new "powerplant units", when they arrive.

4 Seep. 123, last paragraph, end ofsentence 4.April29, 2016 Part 23 Reorganization**FAA~2015~1621** page 19

The FAA acknowledges onp. 124 that Part 33 will not apply to those alternative forms of powerplant units, and that they will need to obtain an equivalent level ofsafety (ELOS) exemption to this rule in Part 23, and produce a new set ofrules equivalent to Part 33 through the Special Conditions rulemakingprocess (Issue Papers). Would one ofthese new types ofpowerplant units receive a type certificate specific to that unit from within Part 23, apart from the airplane in which it resides? 

### IfSpecial Conditions to Part 23 were used, and the airplane was issued a type certificate that includes the new powerplant unit design, but not for the powerplant unit as a stand-alone product, would that powerplant unit be considered to carry a type certificate, ormerely exempt from the need tohave a type certificate? Or, would the FAA seek to find a wayto issue a type certificate for that powerplant unit under Part 33 perthe Special Conditions rulemaking process for that Part? Itwould seem to be a gross misuse ofthe Part 23 rules designed to regulate the airworthiness ofsmall airplanes

- to create a series ofrules for the purpose ofissuing a type certificate for anunconventional powerplant design. It seems that it was intentional bythe original rule makers to isolate the rules governing the airworthiness ofsignificant components ofan airplane (airframe, engine, propeller) such that the rules couldbe written to address the specific needs ofeach type ofmachine without resorting to overly generalized rules (such as, "Airplanes must be safe.") Webelieve that it would be a misuse ofthe flexibility that is being added to the Part 23 rules to try to applythem to the certification ofunconventional powerplant units.
24. 23.910: This rule says you cannothave a**single~point** failure that would preclude continued safe flight and landing. This would seem to rule out all**single~engine** airplanes.
This is about "powerplant system components and accessories", not about the engine itself. We'renot sure ifa fuel line orhose is considered to be a system component, but it would seem that the failure ofthe one fuel line that feeds the engine would certainly result in an engine failure. Itwould seem that there mightbe similarlyinsurmountable scenarios involving the controls for an engine.
Now speaking to the potential for conflict with the FAA in negotiating the meanings of rules, our companyhas had to defend the design of**single~engine** airplanes to FAA specialists who insisted that any loss ofthrust condition in a**single~engine** airplane would be a catastrophic event. Without clearly written rules, unforeseen interpretations ofrules like this have the potential to make the design and certification oflight airplanes much more difficult than they were previously, oreven impossible.
25. 23.920: "The airplane must be capable ofcontinued safe flight and landing under any available reversing system setting." It seems impossible to expect safe flight and landingwith full reverse thrust. It sounds like the FAA expects the airplane to "know" the difference between a pilot command for reverse when the airplane is on the ground, and one issued whenit is still in the air, and**over~**rule the pilot commandifthe airplane is still flying. This might seem tobe an easy control issue when combined with a squat switch, butmany airplanes with spring steelApril29, 2016 Part 23 Reorganization FAA-2015-1621 page 20

fixed landing gears do nothave squat switches. Our companyhas delivered over 3,000 airplanes that have spring-steel fixed landing gear, but also have turbine engines with reverse thrust capability. Other companies (such as Cessna, Quest Aircraft, and Thrush) also manufacture such airplanes.
We understand that reverse thrust can be a safety issue in some airplanes, but we do not believe that it has been a safety issue onthese types ofsingle-engine turboprop airplanes, all ofwhich employ multiple means to prevent inadvertent selection ofthe reverse range, and warning when that range is selected. This rule will be detrimental to our company and our customers, lacking the flexibility that is needed to address the needs ofsuch airplane designs.
26. 23.930(b)(2): We suggest that you add the word "significant" to the phrase, "

...prevent [significant] loss offuel

..." When fuel tanks are full, normal sloshing during taxi or takeoff, or when fuel expands as it warms from ground storage temperatures to air temperatures, can result in small amounts offuel being lost via the vent lines. This should bepermissible.
27. 23.935(b): The title ofthis paragraph suggests that it is intended to cover exhaust systems, but it reads specifically such that it applies to airinduction systems. The way that this paragraph reads now is that "the air induction system

... must provide a means to discharge potential harmful material."
This wording appears to mandate the use ofan inertial bypass particle separator. We do not think this is the intention and suggest making it clearthat this applies to exhaust systems. Ifthe intent was indeed to mandate an inertial separator, then this paragraph does not speakto exhaust systems at all.
28. 23.1000(t) and (g): We suggest adding the words "ifinstalled" after "fire detection system". Otherwise this maybe interpreted as a requirement to have a fire detection system. 29. 23.1300(a)(1): This regulation says that we have to meet the required level ofsafety for systems, but it does not define it. On the top ofp. 144, the FAA says "as the FAA determines which quantitative values satisfied the proposed performance standards, it would sharethat information inFAA guidance". Itis unacceptable to tell industry that it mustmeet a level ofsafety, but the FAAhasn't even decided what that level is. 30. 23.1300(b): Compare this wording to the existingregulation (§23.1309). This may make it easierto certifynon-required equipment. However, an FHA and SSA still seem to be required. Itwould be a much bigger improvement ifthere was a way to relieve the undue burden associated with such system safety analysis for non-required equipment and systems. 31. 23.1310(a)(l): This says that the instruments must show "parameters and trends". Does a round gauge instrumentproduce a trend? Webelieve it does, but will the FAA use this to tryto mandate electronic gauges?April29,2016 Part 23 Reorganization FAA-2015-1621 page 21

This new rule has repurposed the number from the existing §23.1310, which currently addresses a different subject matter. There is great potential for confusion.
32. 23.1330(b): It appears that this maybemorerestrictive than the current §23.1310 in regards to single point failures. This may require that there be no single failure points between thepower supply and the essential load bus.
33. 23.1335(d): "The applicant must design and install taxi and landing lights so they provide sufficient light for night operations." We don't see where the regulations require night operations so we think "ifinstalled" should be added after "taxi and landing lights".
34.23.1400: "Safety and survival equipment, requiredbytheoperatingrules ofthis chapter, must bereliable

..." This mayrequire somekind oftesting or certification offire extinguishers, etc. Would the current UL rating ofthe fire extinguishers be enough? 35. 23.1500(b): This regulation seems to add a lot ofextra requirements to monitor and perform ALL tasks associated with [ALL] systems and equipment. Surely this was not the FAA's intention. We would suggest that you change this to say "

...perform all [required] tasks associated with the intended functions ofsystems and equipment."
Nowregarding the second sentence, "The system and equipment design must make thepossibility that a flightcrew error could result in a catastrophic event highlyunlikely." Unlike a random failure, one cannot put a probability on the likelihood ofa human error. Therefore, any error that anyone can think ofwill be fair game. Additionally, theterm "highlyunlikely" is so vague that it could easilybeinterpreted to mean "that error won't happen". But there is a never-ending list ofways that a crewmember error could (not would) result in a catastrophic event. What ifhe forgets to tum on a needed system at justthe wrong time? (The system must not allow it.) What ifhe inputs the wrong setting atjust the wrong time? (The system must not allow it.) What ifhe goes too fast, goes too slow, banks too much, descends too far, or grabs the wrong control? (The system must not allow it.) Things that would usually be a minor mistake during most circumstances could result in a crash under the most adverse conditions (such as during single-pilot, night, IMC, turbulence, and when tired after a long day). Anyone who thinks that the FAA won'traise these kinds ofscenarios is kidding themselves, because they already do. Ifthe wording ofthis rule is not changed the complexityofsystems inPart 23 airplanes justincreased exponentially for this rule. 36. Appendix A to Part 23: This appendix would over-write an existing appendix (simplified design load criteria), having a different purpose, that was likely necessary for the certification ofsome earlier airplane. All ofthe other appendices are deleted now. It would seem that there will be a lot ofnew airplane projects that reference inactive rules for showing compliance to the new vaguerules. Or, there will be a lot ofwheelreinventing going on
...April 29, 2016 Part 23 Reorganization FAA-2015-1621 page 22

37. 91.323(b)(3): In the special rules that are applicable only to operators ofairplanes in the State ofAlaska, the automatic increase in approved maximumweight has been changed to reflect a maneuvering load factor that is now independent ofthe load factor defined in Part 23, butmatches the previous §23.337 definition.
Now there is increased likelihood that the load factor considered under this new rule will notmatch the load factors that were used inthe original certification ofthe design, because it is possible that some consensus standard will impose some other creative interpretation. Hypothetically, ifthe applicant and the FAA decided that somenew airplane design needed to have a design maneuvering load factor of4.5g to be safe, this regulation would happily give the operator the authority to operate it at a weight no less than 136% ofthe weight for which the manufacturer designed and tested the airplane, and possibly even more. It seems that safetywould be betterpreserved ifthe special Alaska rule was required to reference the load factors that were used in the original certification, whateverthose mightbe. But ofcourse, thepublic will not know that information underthe proposed rules, which will be shrouded inthe secrecy ofwhatever private negotiations for acceptablemeans ofcompliance occurred during the original certification.
This whole automatic gross weight increase thing has always been incongruent with reasonable concerns for safety, which webelieve is part ofthe FAA's mission. What is the purpose ofrequiring manufacturers to do fatigue testing on airplanes thatwill be operated in Alaska?
As a manufacturer ofrestricted category agricultural airplanes we understand the desire to make the most ofthe structural strength ofan airplane design. In ourindustrythe rules ofCAM 8 have beenused for a purpose that is in some ways similar to the results of §91.323 for Alaskan operators, but CAM 8 also imposes restrictions on the maximum maneuvering load factor, orthe limiting design airspeeds, to compensate for overweight operations. Additionally, our airplanes are certified for fatigue with consideration to the weights at which they are actually operated. §91.923 seems to provide no cOmpensating factors for its permitted operation atweights beyond its certified maximum weight.
In closing,
1. These changes are drastic, sweeping, and it is not at all clear that they will produce the positive effects that are desired. Itwould seem to be imprudent to make such changes without significant assurances ofsuccess, orprovide for the continued use ofthe existing rules in the event that the effect is not beneficial.
2. Itdoes not appear that any significantrules have been discarded, onlythat those requirements havebeen consolidated into fewer general orvaguely worded rules, for which acceptable means ofcompliance have not yetbeen established.
3. Ithas been ourconsistent experience that vaguely worded rules lead to more difficult and time-consuming discussions with the FAA, and delayed decisions, not expedited acceptance.April29, 2016 Part 23 Reorganization FAA-2015-1621 page 23

4. It has been ourconsistent experience that FAA acceptance ofpast applicant-based means ofcompliance does not guarantee continued acceptance today, or in the future.
5. Theuse ofconsensus standards maybring flexibility to these rules that will help them accommodate non-standard airplane designs, but itis doubtful that the process for developing such standards will be any more agile orless cumbersome than the existing issue paper system. 

### In fact, it is not clearthat the FAA will use anything other than the issue paperprocess to determine the acceptability ofnew consensus standards.
6. The use ofconsensus standards for most "normal" airplanes will greatlyretard the process ofdeveloping an approved certification plan. Themost expeditious path to achieving an approved certificationplan will be to adopt the means and rule interpretations from the current Part 23 rules (ifpermitted), exceptthat each adoption will now require a discussion (and new critical review) before each is accepted bythe Administrator. It is unclearhowthis repackaging ofthe requirements will be able to save the Applicant anytime ormoneyin achieving type certification.
7. Theuse ofconsensus standards that are developed independently ofanypreviously approved rules will be as time-consuming and expensive as anyotheroption. This is because the FAA will place theburden ofproofthat the means are appropriate on the Applicant, and such standards will require time for critical review and inputbyindustry peers and other experts inthe field priorto presentation to the FAA for acceptance. 8. Theuse ofapplicant-proposed means ofcompliance standards will inevitably lead to significant differences inthe standards that are imposed on different applicants for use on similar products. Such disparity in accepted means ofcompliance will naturally occur with greatervariance as different individuals within the FAA interpret these intentionally more flexible (but also more vaguelydefined) regulations.
9. Theuse ofapplicant-proposed means ofcompliance standards will lead to a significant loss inthe transparency ofthe certificationprocess as individual applicants may choose to make boththeresults and the process ofshowing compliance to anyparticularrule a matter ofproprietary intellectual property, with advantages for maintaining the confidentiality ofsuchprocesses. 10. The costs associated with the use ofconsensus standards that are housed andmaintained bythe ASTM (or some similar group) will deter small companies from accessing and using them. It seems that it will notbepossible to "shop" for the right standards, or study them for possible implementation, without first purchasing them. It is likely that a lot of standards will be purchased that will not get used, and that the best standards that are available will sometimes not be usedbecause they were overlooked orundiscovered due to the costs associated with their discovery.
11. Thenumerical organization ofthe new rules, beinginterleaved with the existing Part 23 rules, will beproblematic. The "decoderring" that will be issued to line up old rules with new rules, for use with hundreds orthousands ofAdvisory Circulars, Policy Statements, Orders, and the like, will soonbe unacceptably confusing.April29, 2016 Part 23 Reorganization FAA-2015-1621 page 24

12. Several rules and all ofAppendix A -havebeen overwritten with dissimilar content, repurposing existingrule numbers. This will lead to confusion.
While we appreciate the intent ofthese proposed changes, we stronglybelieve that these rules, if adopted, will nothave the desired effect on safety, orreduce the costs or time necessary to achieve FAA certification. In particular, these proposed rules

... 1. Will reduce the certainty that is needed to adequatelyplan for the design and certification ofa new airplane; and
2. Will increase the number and duration ofthe interfacing events that the applicant must have with the FAA.
In our opinion, the purposes ofreducing the costs and time necessary to achieve FAA certification would be better served by aprocess that accomplishes the following: 

### 1. Increase the certainty needed to adequately plan for the design and certification ofa new airplane. Retention ofthe current prescriptiverules are the best wayto do this for most airplane designs. For those airplanes ofnon-standard design the issue paperprocess is already in place, and would provide the equivalent ofapplicant-proposed means ofcompliance that this proposal is championing. 2. Reduce the number and duration ofthe interfacing events that the applicant must have with the FAA.
In general, time is spent debating requirements, means ofcompliance, waiting for FAA reviews and approvals oftestplans and analysis that the FAA's experts (DERs) have alreadyreviewed and for which theyhave recommended approval, and procedural steps regarding conformity inspections. The certification process would be the most dramatically improved ifthe FAA would delegate approvals for all substantiation documents to its DERs, including test plans, safety analysis, and flight testing, such that the FAA would onlybeinvolved at the beginning to set the certification basis and approve the certificationplan, during the process to assist and advise the DERs and the Applicant, and at the end to award the type certificate.

Sincerely,

## ~**~**

# cc~ Certification Manager, Air Tractor Inc.