1

U.S. Department of Transportation
FEDERAL AVIATION ADMINISTRATION Office of Aviat io n Policy and Plans Washington, D.C. 20591

INITIAL REGULATORY EVALUATION NOTICE OF PROPOSED RULEMAKING Airplane and Engine Certificat io n Requirements in Supercoo led Large Drop let , Mixed

Phase, and Ice Crystal

Icing Condit io ns 14 CFR PART 25 & 33 OFFICE OF AVIATION POLICY AND PLANS REGULATORY ANALYSIS DIVISION

Michael D. Lukacs June 1 6 , 201023

Executive Summary
................................ ................................ ................................ ..... 4 History
................................ ................................ ................................ ........................... 6 Regulatory Background

................................ ................................ ............................... 7 Assumptions
................................ ................................ ................................ ................. 8 Fleet

................................ ................................ ................................ ............................. 10 Smaller Part 25 Airplane Fleet

................................ ................................ ............... 10 Med ium Airplane Fleet

................................ ................................ .......................... 12 Total Fleet

– Medium and Smaller

................................ ................................ ........ 16 Larger Airplane Fleet

................................ ................................ ............................. 17 Benefits

................................ ................................ ................................ ........................ 20 Averting Events on Small erand Medium Airplanes

................................ ...... 20 Historical SLD Events

................................ ................................ ............................ 20 Estimated Cost Of An SLD Event

................................ ................................ ......... 22 Averting Injuries and Fatalities

................................ ................................ ......... 23 Averting Hull Loss and Accident Investigation Costs

................................ .... 23 Annual Risk

................................ ................................ ................................ ............. 24 Quantified Benefits for Smaller & Medium Airplanes

................................ ........ 25 Benefits from averting events involving larger airplanes

............................... 28 Quantified Benefits

- Large r Airplanes

................................ ................................ ... 29 Benefits from Engine Requirements

................................ ................................ .. 31 Benefit Summary

................................ ................................ ................................ .... 34 Costs
................................ ................................ ................................ ............................ 35 Smaller Airplane Certification Costs

................................ ................................ ........ 36 System Design, Certification & Analysis

................................ .............................. 37 Aerodynamic Wind Tunnel Tests

................................ ................................ ......... 38 Analysis

................................ ................................ ................................ ................... 39 Flight Testing

................................ ................................ ................................ .......... 39 Airplane Certification Cost

- International Impact

................................ .................. 42 New Larger Airplane Certification Cost

................................ ................................ .. 43 Engine Certifi cation Cost
................................ ................................ ........................... 44 Hardware Costs

– Smaller & Medium Airplanes

................................ .................... 46 Fuel Costs

– Smaller and Medium Airplanes

................................ .......................... 47 Smaller Airplanes Fuel Cost

................................ ................................ .................. 48 Medium Airplane Fuel Cost

................................ ................................ .................. 48 Other Airplane Operating Costs
................................ ................................ ............... 49 Cost Summary
................................ ................................ ................................ ............ 50 Benefit Cost Summary

................................ ................................ ............................... 514



## Executive Summary This Notice of

Proposed Rul emaking (NPRM) would amend the airworthiness standards applicable to certain transport category ai rplanes certificated for flight in icing condit io ns and the icing airworthiness standards applicable to certain ai rplane engines. The total
e stimated benefits are $ 40 5
. 6 millio n ($ 99. 5 millio n present value) , and exceed the total estimated costs of $ 71. 0 millio n ($ 54.0 millio n present value)

. On an annualized basis, fo r the time period 2012

- 2064, the benefits are $7.0 millio n, and the costs are $3.8 millio n. The benefits and costs are summarized below. Summary of Benefits and Costs

Nominal Benefits PV Benefits Smaller & Medium Airplanes $249,580,915 $69,994,259 Larger Airplanes $156,004,884 $29,498,469 Tota l Benefits $405,585,799 $99,492,728 ($7.0 million annually) Costs Nominal Cost PV Cost Engine Cert Cost $7,936,000 $6,931,610 Engine Capital Cost $6,000,000 $5,240,632 Total Engine $13,936,000 $12,172,242 Smaller Airplane Certification Cost $24,999,039 $21,835,129 New Larger Airplane Certification Cost $3,154,600 $2,755,350 Derivative Larger Airplane Certification Cost $10,438,800 $9,117,652 Hardware Costs $10,390,000 $5,842,024 Fuel Burn All $8,046,676 $2,261,941 Total Costs $70,965,115 $53,984,338 ($3.8 million annually)

Fi rst , we explain the accident history and background that led to this NPRM. Next , we provide the regulatory

b ackground

of the requi rements contained in the proposed rule. Thi rd , we det ail our assumptions and estimates of the fleetthat would be affected by the5

proposed requirements. Finally, we examine the estimated benefits and costs associated wi th the proposed rule, and follow it with the benefit/cost summary

. We have determined th at this proposed rule: (1) has benefits that justify its cost ; (2) i s not an economically “significant regulatory act io n” as defined in sect io n 3(f) of Execut ive Order 12866 ; (3) i s “significant” as defined in DOT ’ s Regulatory Policies and Procedures; ( 4) would not have a significant economic impact on a substant ia l number of small ent it ies; (5) would not create unnecessary obstacles to the foreign co mmerce of the United States; and (6) would not impose an unfunded mandate on state, local, or tribal gove rnments
.6



## History On October 31, 1994, an Avio ns de Transport Regio nal ATR 72 series airplane crashed in Roselawn, Indi ana, resul ting in the deaths of 68 passengers and crew members. After extensive invest igat io n, th e Nati onal Transportation Safet y Bo ard (NTSB ) concluded that freezing drizzle condit io ns created a ridge of ice on the wing’s upper surface aft of the dei cing boots and forward of the ailerons , and that th e ridge of ice contributed to an
unco mmanded roll of the airplane. The atmospheric co ndit io n th at con tributed to the Roselawn accident i s current ly outside the icing envelope for certificat io n of transport category ai rplanes

. The accident would not have occurred had the proposed requirements been in affect at the time of airplane design.

The certificat io n r equi

rements f or transport category

ai rplanes and engines do not address th e safe operation of airplanes in supercooled large drop let( SLD ) , mixed phase, or ice crystal i cing condi

ti ons , and the operating rules do not specifically proh ibit operations in th ese condit io ns. The proposed requirements contained in this NPRM are based on recommendat io ns by both the NTSB 1 and Aviat io n Rulemaking Advisory Committee (ARAC)

. 2 We estimate the benefits and costs associated with certifying designs to these requi rements in the fo llo wing sect io ns.

1 NTSB recommendations A

- 96

- 54, A

- 96

- 56, and A

- 96

- 58; available in the Docket and on the Internet at: http://www.ntsb.gov/Recs/letters/1996/A96_48_69.pdf.

2 Ice Protection Harm onization Working Group7



## Regulatory Back

ground Ti tle 14, Code of Federal Regulat io ns, part 25, a ppendix C , and p art 33 specify t he certification requirements for icing condit io ns . Icing condit io ns containing freezing drizzle and freezing rain are not currently considered during cert ificat io n of an airplane’s ice protection systems. These two co ndit io ns consti tute an icing envi

ronment known as SLD. E xposure to these condit i ons can result in ice accretion that impair s the safe ope ration of an ai

rplane

. Thi s rule would requi re airplanes to eit her safely exi t f ol lo wing th e detection of

any specifically

i dent ified a

ppendix O ic ing condit io ns, or safely operate wi thout restri ct io ns. Specifically, the proposed § 25.1420 would allo wthree options:

 § 25.1420(a)(1)

- detect a ppendix O condi

ti ons , and then operate safely while exit ing all icing condit io ns.

 § 25.1420(a)(2)

- safely operate in a selected portion of a ppendix O , detect when the airplane is operating in condit io ns that e xceed the selected portion, and then operate safely while exit ing all icing condit io ns.

 § 25.1420(a)(3)

- operate safely in all of the a ppendix O condi

ti ons .

Similarly, SLD condit io ns are not currently considered during engine certificat io n. Exposing engines and externally mounted probes to these condit io ns can result in hazardous ice accumulat io ns that may resul t in engine damage, power loss, and loss of or misleading airspeed indicat io ns.
The proposed regulat io ns would reduce th e ri sk of accidents by including certificat io n requi rements for ( 1 ) SLD i cing condi ti ons f or transport category

ai rplanes most affected by these icing condit io ns ; ( 2 ) mixed phase and ice crystal condit io ns fo r all transport8

category ai rplanes ; and ( 3 ) SLD , mixed phase, and ice c ry stal i cing condi

ti ons f or all turbine engines.

This regulatory

evaluat io n estimates the total addi ti onal incremental benefits and costs of t he proposed requirements contained in the rule. We obtained the basis of ourcost estimates f

rom th e industry

. The manufacturers based their est imates upon accompanying a dvisory c ir culars (AC) , which describe acceptable means for showing
com pliance. The com

pliance costs are analyzed in context of the part 25 and part 33 certification requirements

. We have evaluat ed the operational costs based upon estimates and analysis o f operators who routinely operate in SLD environments.

The FAA seeks co mments on its determination of the costs and benefits and requests that all co mments contain supporting data and addit io nal documentation. 

## Assumptions The soci etal

costs include th e overhead costs that are allocated to labor as well as the di rect cost. The basis for the labor rates are from the 200 9 data on th e mean burdened hourly l abor rates of aeronautical engineers usingdata principally from the Department of Labor ’s Bureau of Labor Statist ics. On that basis , we use $ 77 per hour as the burdened wage rate for engineers used in this regulatory evaluation.
For purposes of this evaluat io n , we conservatively assume that a ll certificat io ns are approved one year af

ter the rule is codified (2011) , and th at production/deliveries begin to occur the fo llo wing year (2012). The number of deliveries and the corresponding9

delivery y ears depend on the airplane t ype . We explain thes e numbers in the fleet section of thi s analysis

. This producti on and delivery profile creates a slowly

building fleet , until producti on stops. Once airplanes reach 25 years, they start to retire. 3 Because the producti on cycles and deliveries are customi zed to the various (and different) airplane ty pes, i t i s important for the reader to focus on present value benefit s and costs.

The est imated benefit s are larger than the estimated costs for the lifecycle o f ai rplanes th at are certificated , delivered, o perated , and retired; and th e rule will b e cost
- beneficial fo r all f uture certificated airplanes.
This analysis focuses on incremental benefit s and costs that accrue to cit izens and manufacturers in the United States. We acknowledge costs to foreign comp anies who might choose to comply

wi th the requi rements contained in this proposed rule. 4

The est imates in this evaluat io n contain both nominal and present values. For both the benefits and the costs, we use a discount rate of 7% as prescribed by OMB, a s this di scount rate reflects the time value of mo ney. Focusing on present values, allow s f

or a
com parison of benefits and costs over time.

3 BACK Associates Fleet Database 4 OMB Circular A

- 4, pag e 15.10



## Fleet This sect io n outlines the fleet methodology to estimate the number of designs, production rates , and delive ry

cycles of an ai

rplane that would be affected by this proposal . Our reasoning , and the underlying assumptions used in this analysis , are described below.

W e group airplane s int o three categori es: smaller ai rplanes , medi

um airplanes , and larger trans port airplanes , based primarily upon size

. The categories approximate business ai rplanes , regi onal ai

rplanes , and large r ai

rplanes

. The est imated number of certificat io ns and deliveries depend on th e ai rplane t ype . The number of production y ears depends on th e ai rplane category
. 

### SM ALL ER

PART 25 AIRPLANE FLEET To develop the estimated fleet for s ma ller part 25 airplanes , we analyzed histori cal data fo r th e ty pe cert ifications , producti on cycles , and deliveries of similar small er part 25 t ransport category airplanes. There are three U.S.

- owned ai rplane manufacturers ( Cessna, Rayt heon, and Gulfstream ) current ly producing small er part 25 ai rplanes. In addi ti on , Learjet, a subsidiary of Bombardi er, manuf

actures part 25 airplanes in this cate gory wi

thin the Uni

ted States. We analyzed

these manufacturers’ ty

pe designs and th ei r associ ated annual airplane deliveries result ing fro m new airplane certificat io ns fo r U.S. manufacturers from 1966 th rough 2007. The data is summarized in t able 1 below

. TABLE 1

– SMALLER CERTIFICATION SUMMAR Y

Years (1964 - 2007) Total Count of New Designs 11 Designs per Year 0.250 U.S. Deliveries 3122 U.S. Deliveries Per Period Per Ty pe Certificate ( TC ) 33 Estimated Number of Designs in 10 years 3 Annual Deliv eries To U.S. Per TC 9911

From 1964 th

rough 2007 , there were approximately 3.0 new ai rplane t ype certificates per 10

- year period for smaller airplane s . As detailed in table 2 , f or each ty pe design, on average, there are roughly 33 deliveries in the U nit ed States annually (3, 118 deliveries to th e U.S. / 95 TC ye ars 5 )

. For the total number of type certificates (3), we estimate 99 ai rplanes would be delivered annually

. TABLE 2

– SMALLER PART 25 DEL IVERIES

5 Number of Years of deliveries per new type certificate data sheet (TCDS). The average number of years produced is 10 years.12

Shown below is the affected fleet fo r smaller airplanes. It is based on three ty pe designs, 33 annual deliveries per ty pe design (which equates to 99 annual deliveries) , 1 0 year s of deliver ies per ty

pe design , and an airplane retirement of 25 years on average.
TABLE 3 - SMALL ER A IRPLANE FLEET Year Deliveries Retirements Net Fleet 2009 Effective Date of Rule 2010 3 Certifications Occur 2011 Deliveries Begin 2012 99 99 2013 99 198 2014 99 297 2015 99 396 2016 99 495 2017 99 594 2018 99 693 2019 99 792 2020 99 891 2021 99 990 2022 990 2023 990 2024 990 2025 990 2026 990 2027 990 2028 990 2029 990 2030 990 2031 990 2032 990 2033 990 2034 990 2035 990 2036 990 2037 99 891 2038 99 792 2039 99 693 2040 99 594 2041 99 495 2042 99 396 2043 99 297 2044 99 198 2045 99 99 2046 99 0 

### MEDIUM AIRPLANE FLEET The delivery and production data for similar medium transport category ai

rplane ty pe certificates are s ummarize d in t able 4
. To e st imate the affected potential fleet of med ium13

ai rplanes/regi onal ai

rplanes , we use available his tori cal data f or similar airplanes as suggested by

industry representatives

. TABLE 4 - MEDIUM AIRPLANE PROD UCTION Model Deliveries Producti on Years Jetstream J41 100 6 ATR 42

- 72 808 23 EMB
- 120 352 17 EMB
- 135/EMB

- 145 875 12 Dornier 328 66 8 DHC

- 7 111 12 CL600 1641 11 DHC

- 8 507 22 SAAB 340 430 14 SAAB 2000 63 5 Fokker 27/50 992 39 Fokker 28 241 20 BAE 146/AVRO RJ 391 19 To tal 6577 208
The data summarized in table 5, r epresents similar designs fo r the 1965

- 1999 time peri od

. 6 Based on this history, roughly 0.4 medium transport ai rplanes are certificated annually. Accordingly, w e est imate fo urmedium transport certificat i ons will occurover a ten year peri od , and

we conservatively assume all certificat io n approvals occur in 2011. TABLE 5 - MEDIUM AIRPLANE CERTIFICATION SUMMARY Years (1965

- 1999) Total Count of New Designs 13 Designs Per Year 0.4 Total Deliveries 6577 Deliveries Per Period Per TC 32 Estimated Number of Designs in 10 years 4 Annual Deliveries To U.S. Per TC 17 The approximate annual number of worldwide deliveries o f med ium ai rplanes per ty

pe certificate is 32 (6,577 airplanes/208 years). O f t hese , roughly 32 affected ai rplane s delivered annually

on a worldwide basis, 52% ( 1 7 ai rplane s per ty

pe design) are expected

6 Industry gave the FAA input in the analysis of the time periods used for the different categories of aircraft. The c ategories and time periods analyzed depended on several factors in coordination with industry input such as the original type certifications, historical delivery and production schedules (for both in production and out of production airplanes) for each spe cific category of aircraft.14

to be delivered and operated in the United States annually. For a 16

- year production peri od (the medium airplane average) , 68 med ium ai rplane s will

b e delivered annually to th e U.S. ( 4 certificat io ns x 17 ai rplane s ). We use the transport category ai rplane service life (25 years). Table 6 shows the estimated fleetover time wit h the corresponding ai rplane producti on, deliveries, and reti rements for medium

transport category ai

rplane s .15 TABLE 6

– MEDIUM AIRPLANE FLEET

Year Deliveries Retirements Net Fleet 2009 Effective Date of Rule 2010 2 Certifications Occur 2011 Deliveries Begin 2012 68 68 2013 68 136 2014 68 204 2015 68 272 2016 68 340 2017 68 408 2018 68 476 2019 68 544 2020 68 612 2021 68 680 2022 68 748 2023 68 816 2024 68 884 2025 68 952 2026 68 1020 2027 68 1088 2028 1088 2029 1088 2030 1088 2031 1088 2032 1088 2033 1088 2034 1088 2035 1088 2036 0 1088 2037 68 1020 2038 68 952 2039 68 884 2040 68 816 2041 68 748 2042 68 680 2043 68 612 2044 68 544 2045 68 476 2046 68 408 2047 68 340 2048 68 272 2049 68 204 2050 68 136 2051 68 68 2052 68 016



### TOTAL FLEET

– SM ALLER AND MEDIUM Aggregat ing the airplane sizes accounts for various sizes of ai rplanes that would be affected by

the proposed rul e. For purposes of this evaluat io n , we co nservat ively assume th at all cert ifications are approved one year after the rule is codified (2011) , and th at producti on/deliveries begin to occur the fo llo wing year (2012). The estimated number of certifications, deliveries , and producti on years depend o n ai rplane t ype. As detailed in
our previ ous fleet di scussi on, t he total annual affected fleetf or smaller and medium ai rplanes equals the total

annual net number of smal l eraffected ai rplane s plus the total annual net number of medium airplanes

. Table 7 shows the total affected fleet for smaller and medium airplanes. TABLE 7

– TOTAL SMALLER AND MEDIUM AIRPLANE FLEE T Smaller Deliveries Small er

Retirements Net Fleet

Smaller Airplanes Medium

Deliveries Medium

Retirements Net Fleet

Medium Total Net (Net

Smaller + Net Medium) 2012 99 0 99 68 0 68 167 2013 99 0 198 68 0 136 334 2014 99 0 297 68 0 204 501 2015 99 0 396 68 0 272 668 2016 99 0 495 68 0 340 835 2017 99 0 594 68 0 408 1002 2018 99 0 693 68 0 476 1169 2019 99 0 792 68 0 544 1336 2020 99 0 891 68 0 612 1503 2021 99 0 990 68 0 680 1670 2022 0 0 990 68 0 748 1738 2023 0 0 990 68 0 816 1806 2024 0 0 990 68 0 884 1874 2025 0 0 990 68 0 952 1942 2026 0 0 990 68 0 1020 2010 2027 0 0 990 68 0 1088 2078 2028 0 0 990 0 0 1088 2078 2029 0 0 990 0 0 1088 207817 Smaller Deliveries Small er

Retirements Net Fleet

Smaller Airplanes Medium

Deliveries Medium

Retirements Net Fleet

Medium Total Net (Net

Smaller + Net Medium) 2030 0 0 990 0 0 1088 2078 2031 0 0 990 0 0 1088 2078 2032 0 0 990 0 0 1088 2078 2033 0 0 990 0 0 1088 2078 2034 0 0 990 0 0 1088 2078 2035 0 0 990 0 0 1088 2078 2036 0 0 990 0 0 1088 2078 2037 0 99 891 0 68 1020 1911 2038 0 99 792 0 68 952 1744 2039 0 99 693 0 68 884 1577 2040 0 99 594 0 68 816 1410 2041 0 99 495 0 68 748 1243 2042 0 99 396 0 68 680 1076 2043 0 99 297 0 68 612 909 2044 0 99 198 0 68 544 742 2045 0 99 99 0 68 476 575 2046 0 99 0 0 68 408 408 2047 0 0 0 0 68 340 340 2048 0 0 0 0 68 272 272 2049 0 0 0 0 68 204 204 2050 0 0 0 0 68 136 136 2051 0 0 0 0 68 68 68 0 0 0 0 0 68 0 0



### LARGE R A IRPLANE FLEET The proposed design requirements contained in §§ 25.773, 25.903, 25.929, 25.1093, 25.1323, 25. 13 24 (angle of attack systems), 25.1325 , 25.1521, and 25 .1533 wo uld extend to all transport category ai rplane s . Table 8 summarizes th e certificat io ns fo r current U.S.
m anufacturer s of large r ai rplane s .18

TABLE 8

– LARGE R AIRPLA NE CERTIFICATIONS TC Model Total Production Years 1958 DC

- 8 310 14 1963 727 1287 22 1965 717, 1290 42 1967 737 2855 42 1967 G

- 1159 983 41 1970 747 296 40 1971 DC

- 10, 315 30 1982 757 730 23 1982 767 429 22 19 95 777 229 14

Total 8,724 290
We use summarized data in table 9 to estimate the number of future certificat io ns of large r ai rplane s . T he historical evidence shows that , on average, large r ai rf rame manufacturers in th e United States receive approval fo r 0.2 new ai rplane ty pe certificates per year , which equates to roughly 2 over a 10

- year period. Table 9 - Summary Data for Large r Airplane Certifications Years (1958

- 2006) Total Count of New Designs 10 Designs Per Year 0.2 U.S. Deliveries 8,724 U.S. Deliveries Per Period Per TC 31 Estimated Number of Designs in 10 years 2 The approximate annual number of deliveries to the U.S. of large rai rplanes per ty

pe certificate is 3 1 ( 8,724ai

rplanes/ 290 producti on ye ars) , and we estimate the approximate number of

producti on years is 29 . Table 10 shows the estimated fleet for large r ai rplanes

. There are 2 ty

pe certificates, followed by 2 9 year s of deliveries wit h 62 ai rplanes delivered annually . We use the same transport category ai rplane service life (25 years ).19

TABLE 10

– LARGER AIRPLANE FLEET Year Deliveries Retirements Net Fleet 2009 Effective Date of Rule 2010 2 Certi fications Occur 2011 Deliveries Begin 2012 62 62 2013 62 124 2014 62 186 2015 62 248 2016 62 310 2017 62 372 2018 62 434 2019 62 496 2020 62 558 2021 62 620 2022 62 682 2023 62 744 2024 62 806 2025 62 868 2026 62 930 2027 62 992 2028 62 1054 2029 62 1116 2030 62 1178 2031 62 1240 2032 62 1302 2033 62 1364 2034 62 1426 2035 62 1488 2036 62 62 1488 2037 62 62 1488 2038 62 62 1488 2039 62 62 1488 2040 62 62 1488 2041 62 1426 2042 62 1364 2043 62 1302 2044 62 1240 2045 62 1178 2046 62 1116 2047 62 1054 2048 62 992 2049 62 930 2050 62 868 2051 62 806 2052 62 744 2053 62 682 2054 62 620 2055 62 558 2056 62 496 2057 62 434 2058 62 372 2059 62 310 2060 62 248 2061 62 186 2062 62 124 2063 62 62 2064 62 020 BENEFITS As we will show, accidents in apparent SLD conditions tend to be associated wit h stalls, lo ss of control , and catastrophi c outcomes. The purpose of this proposed rule is to prevent such outcomes in the future. The industry and the FAA analyzed the histori cal SLD events fo r ai

rplanes cert ificated under part 25 and part 33

. We ev aluate d all the events f orapplicabilit y and preventabilit y in context of th e requi rements contained in this proposed rule. An event is defined as a n accidentor incidentthat might have been prevented had the requirements in this proposal been in effect during the certification process . We describe the event, provide the basis for benefits , and estimate the risk for th ree categori es of benefits that direct ly align with the proposed requirements.

 Benefit s f

rom avert ing events invo lving small erand mediu m airplanes

 Benefit s f

rom avert ing events invo lvinglarge rai rplanes

 Benefit s f

rom avert ing engine events



### A verting E vents on Small er and Medium A irplanes 

### HISTORICAL SLD EVENT S Below, we examine the histori cal related SLD events for small erand medium air planes. We have included so me basic informat io n on each accident and the j ustificat io n fo r applicabilit y.21

1 ) 4/ 29/1993 An Embraer EMB

- 120 was substant ia lly damaged when i

t collided wi

th rough terrain during an overrun fo llo wing a forced landing. The f orced landing was executed fo llo wing a stall and loss of control at 17,412 feet during climb , which resul ted in damage to the lef

t engine and propeller. Of the 3 crewmembers and 27 passengers aboard, 13 individuals received minor injuries. The NTSB found

that , i n co mbinat io n wi

th other factors , ice accretion led to an aerodynamic stall, loss of control , and a forced landing. Just ification for applicabilit y: The met eorologi cal report indicated the possibilit y of SLD i cing in the area of this accident. Proposed 14 CFR 25.1420 would require a means of detecting a ppendix O condi ti ons for which the manufacturer has not certificated the airplane and would also requi re that the airplane be capable of operating safely wi th in those condit io ns for the purpose of

exit ing those condit io ns.
2 ) 10/31/1994 An ATR

- 72 struck the ground after the flightcrew lost control of the airplane during an adverse roll event at 9,200 feet causing a total of 68 deaths
. The NTSB found that the probable cause of the accident was th e loss of control , attributed to a sudden and unexpected aileron hinge moment reversal that occurred after a ridge of i ce accreted bey

ond the deice boots while the airplane was in a holding pattern. It intermittently encountered supercooled cloud and driz zle/rain drops, the size and water content of which exceeded those described in the icing certificat io n envelope. Just ification for applicabilit y: A ft er encountering large droplet icing condit io ns , the ai rplane stalled and lost control, which may

h ave be en consistent wi

th a ppendix O . Proposed 14 CFR 25.1420 would requi re the ai rplane be able to safely operate in a ppendix O condi

ti ons or have a means of detecting a

ppendix O condi

ti ons and be capable of operating safely wit hin those condi ti ons for the purp ose of exit ing those conditions. 3 ) 12/30/1995 Two fatalities occurred as a result of a Cessna 560 colliding wit h the terrain at the Eagle River Airport, Eagle River, Wisconsin. The NTSB determined the probable cause of the accident was the pilot’s fa ilure to maintain airspeed while executing the circling approach. Factors were de s cent below minimum descental ti tude, fog, low ceiling , and icing condit io ns. Alt hough the ice accret io n was not described as consistent with large droplet icing, a sheriff’s d eput y reported freezing rain and sleet were falling at the time of the accident.22

Just ification for applicabilit y: Exist ing airplanes have not substant iat ed that they are capable of safely operating in a ppendix O (f

reezing drizzle and freezing rain) condi ti on s. Proposed 14 C FR 25.1420 would requi

re the ai rplane be able to safely

operate in a

ppendix O condi

ti ons or have a means of detecting a

ppendix O condi

ti ons and be capable of operating safely wi th in those condi ti ons for the purpose of exit ing those cond it io ns. 4 ) 01/09/1997 An Embraer EMB

- 120RT crashed while being vectored fo r approach to runway 3R at Detroi t Metropolitan Wayne Count y Airport , whi ch resul ted in 29 deaths
. The invest igation revealed that it was likely that the airplane gradually accumu lated a thin, rough glaze/mixed ice coverage on the leading edge deicing boot surfaces, possibly wi th i ce ridge format io n on the leading edge upper surface. The NTSB determined one of the probable causes was the failure to establish adequate ai rplane ce rtificat io n standards for flight in icing condit io ns. Just ification for applicabilit y: Exist ing airplanes have not substant iat ed that they are capable of safely operating in a ppendix O (f

reezing drizzle and freezing rain) condit io ns. Proposed 14 CFR 25. 1420 would requi

re th at newly certificated airplanes safely operate in a ppendix O condi

ti on s or have a means of detecting and exit ing a ppendix O condi

ti ons. 5 ) 3/19/2001 There was an accident invo lving an Embraer 120 , which resulted in neither deaths nor injuries . The NTSB determined the cause of the accident as the failure of the flightcrew to maintain airspeed during an encounter with severe icing condit io ns, which resulted in an inadvertent stall, loss of control, and structural damage to the airplane. Just ification for applicabilit y: The ai rplane encountered SLD i cing. The flightcrew delayed exit ing the condit io ns. Proposed 14 CFR would requi re a means of detecting a

ppendix O condi

ti on s f or which th e manufacturer has not certificated the airplane. It would f urther requi

re that the ai rplane be capable of operating safely within those condit io ns fo r the purpose of exit ing those condit io ns.


### ESTIMATED COST OF AN SLD EVENT As shown in the above events, SLD accidents tend to be asso ci ated wi th stalls , loss of control , and

catastrophic outcomes. We examine d the se histori cal events (that could have been prevented had the requirements of this proposal been in effect ) , and use them as a23

basis for the benefit of averting future events.

Our “ generic ” SLD event is based on the “average” SLD event , and w e find that the histori cal cost of an average SLD event is $ 126.9 millio n. 

### Averting Injuries and Fatalities The first category of benefits associated with an average SLD event is ave rting fatalit ies ($ 6.0 millio n per fatalit y) and averting injuries ($18,000 per injury )

.

For each histori calevent, we m

ul ti ply the average number of past fat alit ies by $ 6.0 millio n and the number of injuries by $18,000. As shown in the fourth colu mn of table 11 , f

or all SLD events, the average cost of averting injuries and fatalit ies is $ 118.9 millio n. 

### Averting Hull Loss and Accident Investigation Costs In addit io n to the injuries and fatalit ies , averting an SLD event would also spare the
a ccom panying hull lo ss and the cost of th e accident invest igat io n. The total est imate for avert ing hull loss and

accident invest igat io n costs is $20.0 millio n per fatal event. T he FAA uses the replacement cost of an airplane operating in scheduled commerc ial service to approximate the value of a destroyed ai

rplane . The replacement val ue f or a single ai rplane is $11.46 millio n 7 and the FAA conservatively assumes there would be no collateral damage. The estimated accident invest ig ation costs are $8.6 milli on . 8

7 “Economic Values for FAA Investment and Regulatory Decisions.” Table 5

- 1, column 3, calculates the weighted average estimated current market value for all airplanes. 8 Ibid24

Table 1 1 summarizes the total estimated cost of an average SLD event at $ 126.9 millio n. This blended event accounts for both the medium airplanes (where there are more seats and passengers) and smaller airplanes (where there are less seats and p assengers). 9


### TABLE 1 1 -AVERAGE SLD EVENT FOR SMALL ER AND MEDIUM AIRPLANES Date of Event Deaths Injuries Averting Injuries & Fatalities Accident

Investigation & Airplane Total

04/29/1993 0 13 $234,000 0 $234,000 10/31/1994 68 0 $408,000,000 $20,006,900 $428,006,900 12/30/1995 2 0 $12,000,000 0 $12,000,000 01/09/1997 29 0 $174,000,000 $20,006,900 $194,006,900 3/19/2001 0 0 $0 0 $0 Average $118,846,800 $8,002,760 $126,849,560 Benefit from averting death $6,000,000 Benefit from averting injury $18,000 

### ANNUAL RISK We estimate annual risk using the proj ected f leet in co mbination wit h the historical rate of preventable events. As shown in the previous section, we have examined therecent history of SLD events for the years 1993 though 2007 and found that there were at least five preventable SLD events during thi s t ime period

. Similarly, the tot al number of ai rplanes operating from 1993 through 2007 was 132,018 10 (see table 1 2 )

. T hese Form 41 numbers represent major, nat io nal , and regi onal carri ers who report commercial service.

9 Three of the events were catastroph ic in nature. 10 Form 41. There are no Form 41 business jet operations (primarily in the small category of aircraft.25

TABLE 1 2

– HISTORIC AL FLEET Year Fleet 1993 6 , 139 1994 6 , 455 1995 6 , 787 1996 7 , 187 1997 7 , 380 1998 8 , 067 1999 8 , 730 2000 8 , 935 2001 9 , 052 2002 11 , 727 2003 90 , 30 2004 10 , 509 2005 10 , 551 2006 10 , 764 2007 10 , 705 FleetYears 132 , 018

T o develop th e overall histori cal likelihood of an accident(f rom 1993

- 2007) , we divide th e minimum number of events ( 5 ) by the sum of the annual

n umber of airplanes in the fleet ( 132,018 )

. Assuming a uniform distributi on

over the analysis period , the annual r isk equals the average annual number of accidents per airplane mu lt iplied by the total net annual affected fleet. The result ( 0.0000378736233 ) is the historical average annual number of

accidents per affected small erand medium ai rplane in absence o f thi s proposed rule. 

### QUANTIFIED BENEFITS FOR SMALLER AND MEDIUM AIRPLANES Aggregat ing the airplane sizes accounts for various sizes airplane s that would be affected by the proposed rule. We calculate the annual est imated quant ified benefits for newly designed and produced smaller and medium airplanes by mult ip lying the ri sk of an accident per airplane by th e expected value of averting an SLD accident and then by th e annual affected fleet. As detailed in our fleet discussio n, the total annual affected fleet is26

th e total annual net number of smaller affected airplane s pl us the total

annual net number of medium ai rplanes. When summed over time, we arrive at the total quant ified benefit s.

Shown in t able 13 are benefit s fo r the period of analysis ending in 2051

. We mult ip ly the net affected fleet by

the annual

risk ( 0.0000378736233 per airplane) and by t he average cost ($ 12 6 .9 millio n) of averting an SLD event

. Again, as the period of analysis is different fro m smaller and medium airplanes versus largerai rplanes, the readershould fo cus th ei r attention on present values. The total estimated benefits are $ 249.6 millio n ( $ 70.0 millio n present value).27

TABLE 1 3

– QUANTIFIED BENEFITS SMALL ER & MEDIUM AIRPLANES Year Net Fleet

Smaller + Medium Annual Risk Per Airplane Nominal Values (risk x fleet x$ 12 6 .9 mil) Present Value

2012 167 0.0000378736233 $802,310 $654,924 2013 334 0.0000378736233 $1,604,620 $1,224,157 2014 501 0.0000378736233 $2,406,930 $1,716,108 2015 668 0.0000378736233 $3,209,241 $2,138,453 2016 835 0.0000378736233 $4,011,551 $2,498,192 2017 1002 0.0000378736233 $4,813,861 $2,801,711 2018 1169 0.0000378736233 $5,616,171 $3,054,825 2019 1336 0.0000378736233 $6,418,481 $3,262,830 2020 1503 0.0000378736233 $7,220,791 $3,430,546 2021 1670 0.0000378736233 $8,023,102 $3 ,562,353 2022 1738 0.0000378736233 $8,349,791 $3,464,866 2023 1806 0.0000378736233 $8,676,480 $3,364,889 2024 1 874 0.0000378736233 $9,003,169 $3,263,163 2025 1942 0.0000378736233 $9,329,858 $3,160,346 2026 2010 0.0000378736233 $9 ,656,547 $3,057,016 2027 2078 0.0000378736233 $9,983,237 $2,953,679 2028 2078 0.0000378736233 $9,983,237 $2,760, 448 2029 2078 0.0000378736233 $9,983,237 $2,579,858 2030 2078 0.0000378736233 $9,983,237 $2,411,082 2031 2078 0 .0000378736233 $9,983,237 $2,253,348 2032 2078 0.0000378736233 $9,983,237 $2,105,933 2033 2078 0.0000378736233 $9,983, 237 $1,968,161 2034 2078 0.0000378736233 $9,983,237 $1,839,403 2035 2078 0.0000378736233 $9,983,237 $1,719,068 2036 2078 0.0000378736233 $9,983,237 $1,606,606 2037 1911 0.0000378736233 $9,180,926 $1,380,832 2038 1744 0.0000 378736233 $8,378,616 $1,177,722 2039 1577 0.0000378736233 $7,576,306 $995,277 2040 1410 0.0000378736233 $6,773,996 $831,664 2041 1243 0.0000378736233 $5,971,686 $685,198 2042 1076 0.0000378736233 $5,169,376 $554,336 2043 909 0.0000378736233 $4,367,065 $437,664 2044 742 0.0000378736233 $3,564,755 $333,885 2045 575 0.0000378736233 $2,762,445 $241,812 2046 408 0.0000378736233 $1,960,135 $160,356 2047 340 0.0000378736233 $1,633,446 $124,888 2048 272 0.0000378736233 $1,306,757 $93,374 2049 204 0.0000378736233 $980,068 $65,449 2 050 136 0.0000378736233 $653,378 $40,778 2051 68 0.0000378736233 $326,689 $19,055 Total $249,580,915 $69,994,25928



### Benefits from averting events involving large r airplanes SLD al so poses a ri sk for large rai rplanes. Al

though the proposed § 25.1420 SLD requi rements would not extend to large rai rplanes, the other design requireme nt s contained in this proposal do not dist inguish based upon airplane weight and therefore extend to large rai

rplanes. French invest igators indicate that a recent Air France A330 accident where 228 people died could have been the result of airspeed indicators failing. Invest igators are considering the possibilit y th at the plane's pitot tubes may have iced over and given dangerously false readings to cockpit computers

. 11 Thi s rule would int roduce new SLD, mixed phase, and ice crystal icing requirements for pit ot tubes. 12

For large rai

rplanes, we assign a 30%

- 40% range of uncertaint y in order to assess the overall potenti al risk to this category of ai rplanes . We estimate 35% as the approximate proporti onal of

the requi rements contained in this rulemaking pa ckage th at wo uld be applicable to larger ai

rplanes . Further, we estimate that35% is the approximate risk th at a large rai rplane would be invo lved in an SLD event

. When mult ip lied, we arrive at 12.3% whi ch represents th e final overall SLD risk for large r ai rplanes. T o quantify the individual risk per airplane (for large rai rpl a nes), we m

ul ti ply th e est imated annual ri sk fo r smaller ai

rplanes ( 0.0000378736233 ) which we developed earlier, b y 12.3 %, whi ch equals 0.00000465845567 . Thi s resul ting value is the estimated annual risk for a large r ai rplane. We m

ul ti ply the est imated annual risk per affected large r ai rplane by the net affected fleet to arrive at the total annual risk for the fleet of large rai rplanes.

11 The accompanying news story can be found at http://www.cbsnews.com/stories/2009/06/09/world/main5074662.shtml 12 The Air France A

- 330 accident was not used in the in the calculations of quantitative benefits that would occur as a result of this proposed rule.29



### QUANTI FIED BENEFITS - LARGE R AIRPLANES The annual expected value o f a large rai rplane accident equal s the affected fleet mult iplied by the cost of an accident then mult iplied by the risk. 13 The total est imated quant ified benefits fo r large rai rplanes equal s the annual expected value of averting a n annualcatastrophic SLD accident summed over the analysis period.

The number of fatalit ies in a catastrophic accident for a large rai rplane equals the load factor m ul tiplied by the number of seats plus the crew(126). 14 Mult ip lying 126 averted fatalit ies by

$ 6.0 millio n (the estimated cost of averting a fatalit y) equals $ 756 millio n. When this total is added to the estimated cost of accident invest igat io n ($8.6 millio n), and th en added to the estimate of airplan e damage ($11.5 millio n) , the total cost of a large r ai rplane accident e qual s $ 776.1 millio n .

Shown in t able 14 are estimated annual and total la rge rai rplane benefit s f

or the period of analysis. We mu lt iply

the net affected fleet by

the annual risk ( 0.00000465845567 per ai rplane) and by

the average cost ($ 776.1 millio n) of averting an SLD eventon a large r ai rplane

. When summed over time, the total est imated benefits are $ 156.0 millio n ($ 29.5 millio n present value).

13 The affected fleet and methodology is shown earlier in the affected fleet discussion. 14 For large airplanes we use tables 9 and 6 of the 2009 Aerospace Forecasts. The average number of seats times the average load factor gives the approximate number of passengers on a large airplane (122). When added to the pilot, copilot, and two crewmembers, the total number of individuals on board would be approximately 126.30

TABL E 14

– LARGE R AIPLANE BENEFITS Year Net Fleet Annual Risk Per Airplane Nominal Values (risk x fleet x$ 776.1 mil) Present Value

2012 62 6 62 2 0.00000465845567 $ 224,145 $ 182,969 2013 124 0.00000465845567 $ 448,290 $ 341,998 2014 186 0.00000465845567 $ 672,435 $ 479,437 2015 248 0.00000465845567 $ 896,580 $ 597,429 2016 310 0.00000465845567 $ 1,120,725 $ 697,931 2017 372 0.00000465845567 $ 1,344,870 $ 782,726 2018 434 0.00000465845567 $ 1,569,015 $ 853,440 2019 496 0.00000465845567 $ 1,793,160 $ 911,551 2020 558 0.00000465845567 $ 2,017,305 $ 958,407 2021 620 0.00000465845567 $ 2,241 ,449 $ 995,230 2022 682 0.00000465845567 $ 2,465,594 $ 1,023,134 2023 744 0.00000465845567 $ 2,689,739 $ 1,043,127 2024 806 0.00000465845567 $ 2,913,884 $ 1,056,126 2025 868 0.00000465845567 $ 3,13 8,029 $ 1,062,959 2026 930 0.00000465845567 $ 3,362,174 $ 1,064,378 2027 992 0.00000465845567 $ 3,586,319 $ 1,061,062 2028 1054 0.00000465845567 $ 3,810,464 $ 1,053,625 2029 1116 0.00000465845567 $ 4, 034,609 $ 1,042,620 2030 1178 0.00000465845567 $ 4,258,754 $ 1,028,545 2031 1240 0.00000465845567 $ 4,482,899 $ 1,011,849 2032 1302 0.00000465845567 $ 4,707,044 $ 992,936 2033 1364 0.00000465845567 $ 4,931,189 $ 972,167 2034 1426 0.00000465845567 $ 5,155,334 $ 949,866 2035 1488 0.00000465845567 $ 5,379,479 $ 926,322 2036 1488 0.00000465845567 $ 5,379,479 $ 865,721 2037 1488 0.000004658455 67 $ 5,379,479 $ 809,086 2038 1488 0.00000465845567 $ 5,379,479 $ 756,155 2039 1488 0.00000465845567 $ 5,379,479 $ 706,687 2040 1488 0.00000465845567 $ 5,379,479 $ 660,455 2041 1426 0.0000 0465845567 $ 5,155,334 $ 591,529 2042 1364 0.00000465845567 $ 4,931,189 $ 528,795 2043 1302 0.00000465845567 $ 4,707,044 $ 471,737 2044 1240 0.00000465845567 $ 4,482,899 $ 419,881 2045 117 8 0.00000465845567 $ 4,258,754 $ 372,792 2046 1116 0.00000465845567 $ 4,034,609 $ 330,067 2047 1054 0.00000465845567 $ 3,810,464 $ 291,336 2048 992 0.00000465845567 $ 3,586,319 $ 256,260 2 049 930 0.00000465845567 $ 3,362,174 $ 224,527 2050 868 0.00000465845567 $ 3,138,029 $ 195,849 2051 806 0.00000465845567 $ 2,913,884 $ 169,963 2052 744 0.00000465845567 $ 2,689,739 $ 146,625 2053 682 0.00000465845567 $ 2,465,594 $ 125,613 2054 620 0.00000465845567 $ 2,241,449 $ 106,723 2055 558 0.00000465845567 $ 2,017,305 $ 89,767 2056 496 0.00000465845567 $ 1,793,160 $ 74,573 2057 434 0.00000465845567 $ 1,569,015 $ 60,983 2058 372 0.00000465845567 $ 1,344,870 $ 48,851 2059 310 0.00000465845567 $ 1,120,725 $ 38,046 2060 248 0.00000465845567 $ 896,580 $ 28,446 2061 186 0.00000465845567 $ 672,435 $ 19,939 2062 124 0.00000465845567 $ 448,290 $ 12,423 2063 62 0.00000465845567 $ 224,145 $ 5,805 2064 0 0.00000465845567 $

- $

- Total $ 156,004,884 $ 29,498,46931



### Benefits from Engine Requirements From 1988

- 2003, there were over 100 documented cases of ice c ry stal and mixed phase engine power loss events. These events are direct ly related to the proposed engine requi rements. Of these events, there were eleven total power loss events 15 f

rom flameouts. One of the events occurred when a Beechjet 400 with PWC J T15D engines had a total power loss at top
- of

- descent and could not relightthe engines. That event resul ted in a dead

- sti ck f

orced landing at Jacksonville airport. Clearly having to relight engines during a flight is a serious event , whi ch can result in an accident. The FAA has examined these historical events and has found that the historical events resulted in about a 12% diversio n rate. 16

Similar to the other design requirements contained in the proposed rule, we have included five of the most sign ificant recent events and include some basic informat io n on each accident and the ju stificat io n fo r applicabilit y. Each of these events could have been mit igated by

the part 33 requi

rements contained in this rule. 17 We also did not include engine damage ev ents where power loss did not occur, but there was core damage. We believe these damage costs would also be averted once the rule is in place. 1) Beechjet Incident

15 Total power loss events are events where all engines loose power at the same time 16 FAA Engine and Propeller Directorate

- This 12% di version rate comes from 17 known diversions out of 141 known power loss events. The list includes the following engine models: JT8D, JT15D, Tay 615/620, CF6

- 80C2, Trent, and ALF502 17 The proposed requirements contained in part 33 focus on mixed phase and ice crystals as the new feature, in additio n to having a ground based icing test that includes SLD. In addition to the events listed, there are also u nscheduled landings that are preventable with the proposed requirements. We conservatively do not estima te these additional benefits , but note that operators will realize cost savings whenever these events are averted.32

NTSB Identificat io n: ENG04IA021 14 CFR 91: General Aviat io n Incident occurred Monday, J uly 12, 2004 , in Sarasota, FL Probable Cause Approval Date: 12/20/2007 Airplane : Ray theon Corporate Jets Beechjet 400A, regi stration: N455CW Note: CAAM 3 due to loss of >3k feet with both engines out. see NTSB web site for narrative: ht tp://www.ntsb.gov/ntsb/brief.asp?ev_id=20040804X01143&key=1 Event Descri

pti on : The Hawker

- Beech Beechjet 400A was descending through flight level 390 when both of the engines flamed out and los t all power while operating in instrument meteorologi cal condi ti ons wi th convective storms in the area. The pilots, after several attempts, were able to get one engine restarted as the airplane was descending th rough 10,000 feet and diverted to a nearby a irport. High

- al ti tude ice crystals had accreted on the compressor vanes and were ingested into the high pressure co mpressor when the pilots retarded the power levers causing compressor surges and flameouts of both engines. Just ification for Revised Rule A pplicabili ty : Proposed revisio ns to 14 CFR 33, § 33.68 would requi

re turbine engines to demonstrate acceptable and safe operation in the proposed mixed phase and ice crystal icing environment of part 33, appendix D. 2) Beechjet Incident NTSB Identificat i on: DCA06IA007
. 14 CFR 91: General Aviat io n Incident occurred November 28, 2005 , in Jacksonville, FL Probable Cause Approval Date: 6/30/2008 Airplane : Ray th eon Corporate Jets Beechjet 400A, regi stration: N691TA Note: CAAM 4 due to forced landing wit h both engines out. S ee NTSB web site for narrative: ht tp://www.ntsb.gov/ntsb/brief.asp?ev_id=20060104X00004&key=1 Event Descri

pti on : The Hawker

- Beech Beechjet 400A was descending through flight level 380 in visual meteorological condit io ns in the vicinit y of cum ulonimbus buildups. Upon reducing power to init iate descent the crew heard a “popping ” noi se , and both engines rolled back. The crew declared an emergency, elected to d ivert to Jacksonville a ir port, and init iated emergency procedures. All attempts to restart the engines were unsuccessful. The crew executed a successful emergency dead

- st ick landing. Just ification for Revised Rule Applicabilit y : Proposed revisio ns to 14CFR 33, § 33.68 would requi

re turbine engines to demonstrate acceptable and safe operation in the proposed mixed phase and ice crystal icing environment of part 33, appendix D. 3) Beechjet Incident NTSB Identificat io n: ENG06IA020
. 14 CFR 91: General Av iat io n Incident occurred Wednesday, June 14, 2006 , in Norfolk, VA Probable Cause Approval Date: 1/31/2008 Airplane : Ray th eon Corporate Jets Beechjet 400A, regi stration: N440DS Note: CAAM 3 due to loss of >3k feet with both engines out.33

S ee NTSB web site f

or narrative: ht tp://www.ntsb.gov/ntsb/brief.asp?ev_id=20060712X00929&key=1 Event Descri

pti on : The Ray

th eon Beechjet 400A was cruising at flight level 380 when both of the engines flamed out after the pilots had reduced power prior to turning on the engine ant i

- ic e systems. The ai rplane was in visual meteorological condit io ns, but was approaching clouds that were known to be remnants of a tropical storm. The left and right e ngines restarted on their own as the airplane descended through flight levels 300 and 240, respectively. Just ification for Revised Rule Applicabilit y : Proposed revisio ns to 14 CFR 33, § 33.68 would requi

re turbine engines to demonstrate acceptable and saf e operation in the proposed mixed phase and ice crystal icing environment of part 33, appendix D. 4) MD - 82 Incident NTSB Identificat io n: CHI02IA151
. Scheduled 14 CFR 121: Air Carrier SPIRIT AIRLINES INC. Incident occurred Tuesday, June 4, 2002 , in Wic hita, KS Probable Cause Approval Date: 1/28/2005 Airplane : McDonnell Douglas MD

- 82, regi stration: N823NK Note: CAAM 3 due to loss of >3k feet with both engines out. S ee NTSB web site for narrative: ht tp://www.ntsb.gov/ntsb/brief.asp?ev_id=20020612X00866&key=1 Event Descri

pti on : The ai

rplane experienced a roll back of engine power on both engines and subsequent ly stalled while in cruise flight at flight level 330. The weathe r condi ti ons were consistent with the presence of ice crystals at the cruise alt it ude. The engine inlet probes became blocked due to the ice crystals , result ing in a false engine pressure ratio (EPR) indication and subsequent retarding of the throttles by the auto

- th

rottle system
. The NTSB stated that factors included the presence of ice crystals at alt it ude, and the icing of the engine inlet probes result ing in a false engine pressure ratio indicat io n. Just ification for Revised Rule Applicabilit y : Engine inlet probes and engine inlet systems are addressed in the proposed revisio ns to 14 CFR 33, § 33.68 , which would requi re turbine engines to demonstrate acceptable and safe operation in the proposed mixed phase and ice crystal icing environment of part 33 , appendix D. 5) Fokker 70 Accident Date: January

5, 2004 Location: N ear Munich Airport Ty pe of ai rplane : Transport Category Ai rplane Manufacturer / Model: Fokker Aircraft B.V. / F28 MK0070 (Fokker 70) Injuri es to persons: Three minor injuries Damage to ai

rplane : Airplane severely damaged Note: CAAM 4 due to forced landing off airport and damaged aircraft. S ee German BFU accident report at BFU web site for narrative: ht tp://www. bfu

- web.de/cln_007/nn_226462/EN/Publicat io ns /Invest igat io n_20Report/2004/Report__04__AX001

- 0__MUC__Fokker,templateId=raw,property =publicationFile.pdf/Report_04_AX001

- 0_MUC_Fokker.pdf34

Event Descri

pti on : A Fokker 70 with Rolls

- Ro yce Tay 620 engines depart ed from Vi enna for a scheduled flight to Munich. While in descent to Munich, at flight level90, heavy engine vibrat io ns were indicated. Thi s occurred after a prolonged t ime under mo derate mixed phase icing condit io ns (snow) and low engine thrust where i ce accreted on the rotors of the low pressure compressors of both engines. The accreted ice then shed and impacted the ice

- impact

- panels thereby dislodging them and blocking the fan bypass duct th at provides primary thrust. The crew declared an emergency due to engine problems and requested to be cleared for an immediate landing. The airplane was immediately

cl eared for a descent. Because the airplane could not maintain the glide slope i t was forced to land approximately 2.5 NM short of the beginning of the runway on a snow covered field with the landing gear partially extended. The fuselage undercarriage was heavily damaged. Just ification for Revised Rule Applicabilit y : This event occurred while operating in mo derate snow condi

ti ons. Part 33 currently does not address snow (mixed phase) condi ti ons. Proposed revisions to 14 CFR 33, § 33.68 would require turbine engines to demonstrate acceptable and safe operation in the proposed mixed phase and ice crystal icing environment of part 33, appendix D. Th e continued incidents, accidents, diversio ns , and power losses demo nstrate the need for th ese proposed engine requi rements. The above events are precursor events th at , if not addressed through rulemaking , could resul t in an unrecoverable power lo ss and
co nsequent fat al accident.


### BENEFIT SUMMARY As summarized in table 1 5 , the total est imated benefits are $ 405.6 millio n ($ 99.5 millio n present value ). Due to the peri od of analysis, the readershould f ocus on the present value benefit est imate of

$ 99. 5 millio n.

TABLE 15 - SUMMARY OF BENEFITS Nominal Benefits PV Benefits Small er & Medium Airplanes $ 249,580,915 $ 69,994,259 Large r Airplanes $ 156,004,884 $ 29,498,469 Total $ 405,585,799 $ 99,492,72835 

### COSTS This regulatory evaluat io n provides the est imated incremental soci etal costs and benefit s fo r the Uni

ted States that would result fro m thi s propo sed rule . Accordingly, we estimate costs to U.S. manufacturers and to U.S. operators. While we estimate costs to int ernat io nal manufacture r s separately, we do not include these costs in the overall United States com

pliance costs

.

Fi rst, we estimate the certificat io n costs to smaller, medium , and larger ai rplanes

. Second, we analyze the addit io nal cost for engine certification and hardware. Lastly, we estimate addit io nal fuel costs and other operating costs.

The total est imated costs of this proposed rule are $71.5 millio n ($54.1 millio n present value). Thi s section discusses how th ese costs are developed. We incorporate manufacturer cost estimates detailingcertification and testing costs . The est imates were based upon the manufacturer’s assessment of the labor hours, equipment , and materi als th at would be requi

red to com

ply wi th all the proposed requirements and are based upon th e accom

panying a dvisory c ir cular s (A C s ) describingan acceptable means for showing
com pliance. For thi s analysis, t he ma nufacturer ’s estimated costs were adjusted fo r inflat io n , our assumpt io ns , and specified labor rates.
The proposed rule would require evaluat ing the operation of newly certificated

ai rplanes in the SLD , mixed phase, and ice crystal i cing environmentand

developing a means to36

different iat e between different Super cooled Large Dropi cing condi ti on s, if necessary

. Specifically

parts 25 and 33 would be amended to address SLD, mixed phase, and ice crystal icing condit io ns. We propose to create a new:

 § 25. 13 24 , Angle of attack systems

 § 25.1420 , Supercooled large dro p i cing condi ti ons

 part 25, a

ppendix O (supercooled large drop i cing condi ti ons)

 part 33, a

ppendix C (this will

be intent io nally

l ef t blank as a placeholder)

 part 33, a

ppendix D (mixed phase and ice crystal icing condit io ns)

In addit io n, the requirements would :

 Expand the certification icing environment to include freezing rain and freezing drizzle.

 Requi re ai rplanes most affected by

SLD i cing condi

ti ons to meet certain safet y standards in the expanded certificat io n ic ing environment, including addi ti onal ai rplane performance and handling qualities requirements

.

 Expand the engine certificat io n regulat io ns , and some airplane component certification regulat io ns (for example angle of attack and airspeed indicating systems) , to include freezing rain, freezing drizzle, ice crystal , and mixed phase icing condit io ns.



## Sm all erA ir plane Certification Co sts Manufacturers provided th e FAA with hourly est imates for the certificat io n cost across th e summary categori es shown in table 16 . Based on their informat io n, the estimated co st37

fo reach small erai

rplane new design is $8.3 millio n. Mul ti plying this new certificat io n costby the number of smal ler ai rplane certificat io ns (3) , th e total new cost f or smaller ai rplane certificat io n is $25.0 millio n ($21. 8 millio n pres ent val ue). Following table 16 , each of the categories is discussed. T ABLE 16 - SMALLER AIRPLANE CE RTIFCATION COST

Smaller AirplaneSummary of Certification CostPer Program System Design $ 107,800 SLD Ice Det
. System Q ual / Certification $ 1 07,800 Supporting Analysis $1,162,971 Total System Design, Certification & Analysis $1, 378,571 Aerody namic Wind Tunnel Tests $1,19 2 ,366 Icing Tunnel Tests $ 43 8 ,868 Total Tunnel Testing $1, 63 1 ,234 Analysis $ 1,200 , 000 Artificial Ice Sh apes -Flight Test $ 725,570 Icing Tanker

- Flight Test $ 1, 676,778 Natural Ice

- Flight Test $2 , 920,960 Total Flight Testing $5, 323, 2 08 Total: $ 8, 334,113 

### SYSTEM DESIGN, CERTIFICATION AND ANALYSIS M anuf acturers expect to incur design, certificat io n , and analysis cost s totaling $ 1.4 millio n

per design

. They

provided detailed hourly estimates for design, certification , and analysis to be in co mp liance with this proposed rule. Table 17 shows t he se detailed estimates wi

th the system

design and cert ificat io n cost breakdown of what the manufacturer might do to showcompliance wit h the requirements contained in this proposed rule

.38

T ABLE 17

– SMALLER AIRPLANE CERTIFICATION COSTS Hours $/

hour 18 Cost System Design S ystem architecture / Integration 1,200 $77 92,400 System Safety Assessment 200 $ 77 15,400 Subtotal 107,800 SLD Ice Det System Qual / Certification SLD Ice detection qualif

ication 300 $77 23,100 SLD Ice detection system certification 1,100 $ 77 84,700 Subtotal 107,800 Supporting Analysis $1,162, 971 Total $1,378,571


### AERODYNAMIC W IND TUNNEL TESTS Wind and icing tunnel test are frequent ly done to reduce the amount of flight tests in natural i cing condi

ti on s because flight testing in general is cost ly. Wind and icing tunnel testing would be performed in order to demonstrate and cert ify to the proposed requi rements and confirm the analysis result s. The cost per design for wind tunnel tests is $1.2 millio n per design , and $0.5 millio n fo r i cing tunnel tests. The details for both sets of test s are shown

in Table 1 7
.

18 See earlier discussion on labor rates.39

T ABLE 1 8

– SMALLER AIRPLANE TUNNEL TESTING Aerodynamic Wind Tunnel Tests Hours US$/hour Cost Model rework $20,000 W ind tunnel rental $1,000,000 Test Proposal

- report 100 $7 7 $7, 7 00 Ice shapes fabrication

–

roughly 5 shapes to be tested 5 Units $2 ,326 $11,630 Conduct ice testing 600 $ 7 7 $46, 2 00 Data analysis 150 $7 7 $11, 550 Test Results

- report 150 $7 7 $ 11,550 Travel expenses $83,736 TOTALWind Tunnel Testing : $1, 192 ,366 Icing Tunnel Tests Model rework (assume available fromother tests) $20,000 Icing tunnel rental $300,000 Test Proposal 100 $ 77 $7, 700 Conduct ice testing 600 $7 7 $46 ,200 Data analysis 150 $7 7 $11 ,550 Test Results

- report 150 $7 7 $11, 550 Travel expenses (industry estimate of 6 people for 2 weeks at a total of $ 3, 489 per week) $41,868 TOTALIcing Tunnel : $ 438,868 Total Tunnel Testing $1,631,234 

### ANALYSIS There i s so me variabilit y in the various manufacture rs’ methods for certificat io n , and each manufacturer ty

pically uses a v ariet y of

analysis and test methods to optimize the ai rplane and ice protection systems design . The addi ti onal analysis f

or com pliance wi

th th e proposed requirements i s expected to cost an average of $1.2 millio n f or each design

. 

### FLIGHT TESTING M anufac turers wo uld perf orm flight testing to show compliance with the requirements contained in th is proposed rul e . The primary purpose of flight testi

ngi s to determine that th e design is effect ive and performs its intended funct io ns during flight as predicted by40

analysis. The flight testing is also used to evaluate any degradat io n in performance and flying qualit ies, to verify the adequacy o f th e flightcrew procedures and limitat io ns , and to confirm that the powerplant installat io n performs satisfactorily whi le in icing condi ti ons. The costs are based upon industry est imates for the approximate number of hours required to demonstrate compliance wit h the proposed requirements. We use the hourly cost of labor as an est imate when appropriate. For hourly unit c osts that differ fro m our standard labor rates, we have updated industry est imates to incorporate inflat io n. The details provided by the industry are shown below and comprise the largest estimated proportion of cert ificat io n costs because they requi re sev eral addi

ti onal it ems th at suppo rt the actual ai

rplane testing (such as but not limit ed to i cing tanker rental , rent ing a chase ai

rplane , and flying the ai

rplane to requi

red location). Table 19 l ists the estimated cost elements with thetotal est imated co st fo r the flight testing acco mpanying each certificat io n of

roughly $5.3 million .41

TABLE 19 - FLIGHT TESTING Hours H our Cost /Hr. Total Artificial Ice Shapes

-Flight Test Campaign Test Proposal

- report (ice shapes + perform.) 200 $7 7 $15 ,400 Ice shapes definition 320 $7 7 $24, 64 0 Ice shapes fabrication 500 $7 7 $ 38,500 Ice shapes installation 250 $7 7 $19, 250 Conduct artificial ice testing 30 $19,771 $593,130 Data analysis 150 $7 7 $11, 550 Test Results

- report 300 $ 77 $23, 100 TOTAL: $72 5,570 Icing Tanker

- Flight Test Campaign Test Proposal

- report 100 7 7 $7, 7 00 Icing tanker rental 20 27,617 $552,342 Cost and time to fly the airplane to tanker place 15 18,7 80 $281,694 "Chaser" rental (to document the tests) 20 4,41 9 $88,375 Conduct icing tanker tests 20 18,7 80 $375,592 Data analysis 150 7 7 $11, 550 Cost and time to fly the airplane back 15 18,7 80 $281,694 Test Results

- report 150 7 7 $11, 550 Flight crew (pilots / maintenance / eng) support $66,281 TOTAL: $1,67 6,778 Natural Ice

- Flight Test Campaign Test Proposal

- report 100 $7 7 $7, 7 00 Cost and time to fly the airplane to SLD area 15 $19,770 $296,550 Icing meteorological support 40 $125 $5,000 Speci fic icing instrumentation for SLD (rental) $160,000 Airplanepreparation (FTI, painting, cameras...) 200 $7 7 $15, 4 00 Conduct natural ice tests in SLD 100 $19,770 $1,977,000 Data analysis 150 $7 7 $11, 550 Cost and time to fly the airplane back 15 $19,770 $296,550 Test Results

- report 150 $7 7 $11, 550 Flight crew (pilots / maintenance / eng) support $139,560 TOTAL: $2, 920,860 Total Flight Testing $5,32 3 , 20842



## Airplane Certification Cost -International Impact Whi le we est imate internat io nal co mp liance costs, we do not include th ese cost s in the overall cost of co mp liance because regulatory evaluations assess the impact on the U.S. economy . As discussed in the flee t analysis, i t was necessary

to estimate the number of designs by foreign co mpanies to determine the number airplane deliveries fro m fo reign manufacturers to the United States.

Current ly there are no United States manufacturers of airplanes who make air planes in th e medium airplane category (primarily co mmercial passenger regi onal j ets). As analyzed in the certificat io n costs, we estimate th e total cost of each new ai rplane certification at $8.3 millio n. During a 10

- year certificat io n peri od, there wou ld be roughly 3 fo reign new medium ai rplane programs as ident ified by manufacturers

. As such, t he int ernat io nal cost to medium airplane foreign manufacturers would be roughly $24.9 millio n.
Based on historical data provided to the FAA from foreign large rai rplane manufacturers , over a period of 10 years, ma nufacturers ident ified 3 addit io nal programs at $1.6 millio n, 8 larger programs at $1.2 millio n and 17 less extensive programs wi th an average cost of $127,050. As such, the total est imated cost to large rai rplane manufacturers is $16.6 millio n. When we add the international cost of large r ai rplane manufacturers ($16.6 millio n) to th e internat io nal cost of medium airplane manufacturers ($24.9 million), t he total estimated cost to foreign fir ms is rough ly $41.5 millio n.43



## New Large r Airplane Certification Cost Some of the proposed certification requirements extend to large rai rplanes. Manufacturers provided the addit io nal amount of time requi

red to show com

pliance wi

th th e proposed rule. The addit io nal c ost per certificatio n equals the addit io nal co mp liance hours mult iplied by

the burdened hourly

cost f or engineers. For the larger airplanes costs are estimated at $1.6 millio n and the breakdown i s shown in table 20
. 19 TABLE 20 - LARGE R AIRPLANE CERTIFICATI ON Hours Cost Per hour Cost 25.773 Pilot compartment view System architecture / Integration 500 $ 7 7 $ 38,500 SSA 200 $ 7 7 $15, 4 00 25.903 & 25.1093 Engines/ Engine Installation Aero analysis 1800 $7 7 $ 138,600 System validation $1,200,000 25.1323 Airspeed indicating system Aero analysis 600 $7 7 $46, 2 00 System validation 600 $7 7 $46, 2 00 25.13xx Aero analysis 600 $7 7 $46, 2 00 System validation 600 $7 7 $46, 2 00 TOTAL: $1, 577,300 These costs equal th e cost per large r certificat io n mult iplied by the total number of
certifications for large r ai rplane s ( 2 certificat io ns) . T he total costof the se requi rements is $ 3.2 millio n ($ 2.8 millio n present value). Industry representatives also provided est imated addit io nal certificat io n costs for addi ti onal programs . The derivat ives cert ificat io n costs are expected to be less co mp lex overall than a new design. As such, manufacturers have provided a range based upon the
com plexi ty of the proj ect. New programs identified by the manufacturer would be the

19 This is a per design cost for each new TCDS.44

mo st expensive costing $1.6 millio n. For larger derivat ive certificat io n proj ects that might include a new engine inst allat io n costs would be $1.2 millio n per program. Less extensive derivat ive programs could be handled through analysis only wit h average cost of $127,050.
Based on historical data, over a period of 10 years , manufacturers ident ified an addi ti onal th ree p rograms (beyond the two new ty pe certificates), fourlarge rderivat ives at $1.2 millio n and 15 less extensive derivates with an average cost of $127,050. As such, th e total cost for derivatives is $10.4 millio n ($9.1 millio n present value).

When we add t he total larger airplane derivative cost of $10.4 millio n ($9.1 millio n present value) to the new larger airplane cost of $ 3.2 millio n ($ 2.8 millio n present value) , th e total estimated cost for large rai rplanes is $13.6 millio n ($11.9 million present value ). 

## Engine Certification Cost Proposed engine design and installat io n requirements would increase costs to engine manufacturers. As such, we analyze and evaluate the part 33 engine certificat io n costs separately . Manufacturers provided data based upon revi sed AC 20

- 147 , Turbojet, Turboprop, and Turbofan Engine Induction System Icing and Ice Ingestion , which shows acceptable compliance methods. As shown in table 21 , total addi ti onal costs f or part 33 designs are roughly

$14.0 millio n ($12.2 millio n present value).45

TABLE 21 - ENGINE COST SUMMARY Nominal Cost PV Cost Engine Cert Cost $7,936,000 $6,931,610 Engine Capital Cost $6,000,000 $5,240,632 Total Engine $13,936,000 $12,172,242 The proposed revisio ns fo r engine certificat io n would change th e environmental requi rements to eval

uat e engine protection and operation in icing condit io ns. The effect of the change would be to requi re an evaluat io n of safe operation in the revised icing environment. The proposed rules would require engines and engine installat io ns to operate safely throughout the SLD condit io ns defined in proposed new part 25, appendix O , and the newly

defined mixed phase and ice crystal condit io ns defined in proposed new part 33, a ppendix D.
Industry has provided data f

or several different engine “sizes , ” and we aggregate this data to determine an average cost per engine certificat io n. The data is further sub

- divided into certification and capi

tal costs
. Table 22 shows t he estimated certificat io n costs at $496,000 per program. These costs are expected to occur once for every new certification program.46

TABLE 22

– ENGINE COSTS PER CERTIFICATION Average Cert. Costs Engine Analysis (Mixed Phase Glaciated) $ 30,000 Engine Analysis SLD $ 50,000 Engine Icing Tests $ 300,000 Ice Slab Testing (Saved) $ (100,000) Soft Body Tolerance Analysis $ 116,000 Test Facilities $ 100,000 $ 496,000
Fr om 1996

- 2005 , there were 16 new part 33 turbine engines , or 1.6 engines per year. For thi s analysis , we assume all 16 engine cert ifications would occur in 2011

. Wit h certification costs of $496,000 per certification, th e total estimated engine cert ificat io n costs are $7.9 million

($7.0 million

present val

ue).

In addit io n to these certificat io n costs, there would be addit io nal capital costs to modify manufacturer facilit ies in orderto provide an ice crystal cloud (as way of showing
com pliance wi

th the proposed requirements) . The es timated cost i s $1 million per engine manufacturer

. We expect all 6 m anufacturers of part 33 engines to incur t his cost in 2011 , fo r a total cost of

$ 6.0 ($5.2 millio n present value)

.

T he capital cost of $6.0 ($5.2 millio n present valu e) pl us the certificat io n cost of $7.9 million

($7.0 million

present val

ue) equal s the t otal engine costs of $ 14.0 millio n ( $ 12.2 millio n present value). 

## Hardware Costs

–

Small er and Medium Airplanes The industry est imates there would be addit io nal SLD i ce detectors co st s at $10,000 for approximately

1⁄2 of the estimated affected deliveries of small erand medium airplanes.47

Industry est imates that roughly 50% of airplanes might be certified using visual cues and th e remaining mi ght be c ertified with detectors. When the ice detector costs of $10,000
are m ul tiplied by the est imated fleet per year and summed costover the period of analysis, the total estimated hardware costs are $ 10.4 millio n ($5.8 millio n present value). 

## Fuel Costs

–

S ma ll erand Medium Airplanes These proposed requirements w ould add operating costs from th e addi ti onal hardware and acco mpanying weight changes on each small erand med ium airplane. In thi s analysis, we incorporate the recent co st of fuel fo recast using dat a from the FAA Aerospace Forecast 2009

- 2025. We use this forecast along with the fuel consumpt io n methodology

as explained in F AA’s guidance, Economic Values for FAA Investment and Regulatory Decisions 20 , and the estimated average incremental fuel cost of 19 2 cents per gallo n 21 in order to estimate the addit io nal cost of fuel per affected airplane

. Again, w e use th e 50% factor to account fo rour fuel consumpt io n cost estimates as only 1⁄2 of the fleet would incur the cost of carrying the addit io nal SLD ice detectors. Fi rst, we estimate the additional fuel cost for small er ai rplanes f ol lo wed by the est imated costs for medium ai

rplanes

. 22

20 For the additional fuel consumption estimat es, the FAA uses 0 .005 gallons per flight hour per pound of additional weight. As shown in table 6

- 1 of Economic Values for FAA Investment and Regulatory Decisions , this is equivalent to a passenger B oeing Model 737

- 300 airplanewith a median stage lengthof 500 nm and an Emb

rae r Model ERJ
- 135 airplanewith a median stage length of 250 nm. 21 Cents expressed in 2009 dollars. 22 Industry

has informed us that there are no estimated additional costs for large airplanes.48



### SMALL ER

AIRPLANES FUEL COST The addi ti onal incremental

weight im

pact is first mult iplied by the fuel burn factor per ai rpla ne. The product mult ip lied by the flight hours and then by the cost of fuel equals th e annual addit io nal fuel consumpt io n cost.

For small erai

rplanes, we calculate the annual additional cost of fuel by m ul tiplying the estimated addit io nal hardware we ig ht of approximately 19 pounds by the fuel burn factor of 0 .005 gallo ns per hour per pound to arrive at 0.0935 gallons per hour per airplane. This product is then mult iplied by the annual flight hours per airplane o f 402 hours 23 and finally by the cost of

f uel ($ 1.92 /gallo n) to arrive at the fir st yearannual est imated addi ti onal cost of f uel f or each small erai

rplane of $ 7 3
.

Once we calculated th e estimated annual addit io nal fuel cost per smaller ai rplane, we mult iplied thi s addi

ti onal cost by the af fected fleet. The industry expects roughly one half o f th e estimated affected fleet would not incur such costs. When mult iplied by the affected annual fleet of

small er ai

rplanes th at would incur cost because of this proposal , and summed over the period o f analysis , the total small erai

rplane fuel

cost i s $ 0.9 millio n ($ 0.3 millio n present value).


### MEDIUM AIRPLANE FUEL COST Similarly, f

orthe category

of medium ai rplanes , we calculate the annual addi ti onal cost of f uel by m ul ti ply ingthe est imated addit io nal hardware weight of 19 .2 pounds by the fuel burn factor of 0 .005 gallons per hour per pound to arrive at 0.0935 gallons per hour

23 2007 GA Survey

–

Table 1.1 & 1.4 Tu

rb ojet Total (353,400 hours / 880 aircraft)49

per airplane. We m

ul ti plied 0.0935 by the 2,878 annual flight hours per airplane 24 and finally by the cost of fuel ($ 1.92 /ga llo n) to arrive at the total annual estimated addit io nal fuel cost of $ 525 fo r each med ium airplane operating in co mmercial service

. T he total estimated addit io nal

f uel cost equals $ 5 25 per ai rplane mult ip lied by fift y percent of the estimated affected fl eet th at would incur such costs . When summed over time, th e estimated addi

ti onal f uel consumpt io n costs f

or medi um airplanes are $ 7. 1 millio n ($ 2
. 0 millio n present value).


## OtherA irplane Operating Costs The FAA originally asked ARAC to estimate other operati onal costs b ey ond the addi ti onal hardware and fuel consumpt io n costs . Accordingly, ARAC provided this data to the FAA. However, a s we neared complet io n of ourcostanalysis for these requi rements , we queried individual operators and Chief Pilots informed us they were al ready in co mp liance and there were no a ddit io nal operati onal costs beyo nd fuel and hardware.

When asked about the exist ing operati ons in SLD , Chief Pilots referenced AC 91

- 51A , Effect of Icing on Aircraft Control and Airplane Dei ce and Anti

-Ice Systems , where:

“...Pilots can minimize the chance of a roll upset by being sensi

tive to cues that ident ify severe icing condit io ns before control or handling characterist ics of the ai rplane are degraded to a hazardous level

. ”

24 DOT, Form 4150

In addit io n t o the guidance document s and crew training , operators referenced airplane flight manual s that requi

re th e flightcrew to exit severe icing condit io ns ( which might include SLD icing condit io ns )

. They recognize the dangers of operating in SLD condi ti ons and avo id these condit io ns. O perators routinely, and on a regular basis , incur SLD operational costs from diversi on s by exit ing SLD condi ti ons, divert ingto al

ternate ai rport s , and cancelling flights

. O perators acknowledge th ese as exist ing cost s and agree t here might be only minimal incremental costs as a result of the certificat io n requirements contained in this proposal. 25 

## Cost Summary T he est imated total cost f or the period of

analysis is $ 71. 0 millio n ($ 54 .0 millio n present value). Table 22 details the costs by category
. The present value costs will be co mpared to the present value benefit s in the benefit/cost summary

.

25 Impacts on Dispatch

- Manufacturers believe compliance with the proposed rule would result in a decrease in passenger payload (of 5 passengers) during SLD conditions due to a decrease in medium airplane performance. This performance limitation is expected to occur only in SLD conditions (not ever y flight o r under normal operating conditions). When an operator takes off or plans to take off in SLD conditio ns, it is expected that it would offload 5 passengers (or equal weight) to offset performance limitations. This would equate to a revenue decrease of roughly $390 per flight. Data from the industry was used to estimate 0.09 as the performance limited flights taking off into SLD. When multipli ed by the estimated decrease in revenue per flight ($390), total annual costs are approximately $35, which we believe is minimal. For the affected fleet of medium airplanes, the total estimated impact on dispatch is $15,960 ($3,878 present value).51

TABLE 23 - COST SUMMARY Nominal Cost PV Cost Engine Cert Cost $7,936,000 $6,931,610 Engine Capital Cost $6,000,000 $5,24 0,632 Total Engine $13,936,000 $12,172,242
Small er Airplane Certification Cost $24,999,039 $21,835,129 New Large

r Airplane Certification Cost $3,154,600 $2,755,350 Derivative Large

rAirplane Certification Cost $10,438,800 $9,117,65 2 Hardware Costs $10,390,000 $5,842,024 Fuel Burn All $8, 046,676 $2, 261,941
Total $ 70,965,115 $ 53,984,338 

## Benefit Cost Summary The affected fleet and categories of benefits and costs are analyzed over different time peri od s and are c ustomized to the requirements of this proposal. It is important for the reader to focus on present valuebenefits and costs. As such, the total est imated benefits are $ 405.6 millio n ($ 99. 5 million present value). The total est imated costs are $ 71.0 millio n ($ 54.0 millio n present value). On an annualized basis, for the time period 2012

- 2064, the benefits are $7.0 millio n, and the costs are $3.8 millio n. Accordingly, the benefits of the rule just ify the costs, and the rule is cost beneficial.