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U.S. Department of Transportation

FEDERAL AVIATION ADMINISTRATION

Office of Aviation Policy and Plans

Washington, D.C. 20591

FINAL REGULATORY EVALUATION

FINAL RULE

Airplane and Engine Certification Requirements in Supercooled Large Drop, Mixed 

Phase, and Ice Crystal Icing Conditions

14 CFR Parts 25 & 33

OFFICE OF AVIATION POLICY AND PLANS

REGULATORY ANALYSIS DIVISION

December 2013
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Table of Contents

Executive Summary......................................................................................................... 3

History............................................................................................................................... 4

Regulatory Background .................................................................................................. 5

Assumptions ..................................................................................................................... 7

Fleet.................................................................................................................................... 8

Benefits ............................................................................................................................ 20

Costs................................................................................................................................. 41

Benefit Cost Summary................................................................................................... 60

Appendix......................................................................................................................... 62
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Executive Summary 

The FAA is adopting this final rule to revise certain regulations in Title 14, Code 

of Federal Regulations (14 CFR) part 25 Airworthiness Standards: Transport 

Category Airplanes and part 33 Airworthiness Standards: Aircraft Engines 

related to the certification of transport category airplanes and turbine airplanes

engines in icing conditions. The following table shows the estimated total

benefits exceed the estimated costs.

* Details may not add to row or column totals due to rounding.

These values are over the lifetime of the affected airplanes. As the lifetimes of 

large and small part 25 (commercial airplanes and private jets) are different we 

will also provide the present values over their analysis period. Clearly, however 

we express the benefits and costs, preventing icing related accidents has 

substantial benefits relative to the costs. Viewed from a breakeven analysis using 

only preventable fatalities, with each fatality valued at $9.1 million, this rule has 

benefits exceeding costs with only 7 fatalities prevented. 

First, we explain the regulatory background of the requirements contained in the 

final rule. Next, we detail our assumptions and the accident and incident history 

that led to the final rule. Then, we estimate the fleet that will be affected by the 

final rule requirements. Finally, we examine the estimated benefits and costs 

associated with the final rule, and follow with a benefit/cost summary. 

We have determined that this final rule: (1) has benefits that justify its cost; (2) is 

not an economically “significant regulatory action” as defined in section 3(f) of 

Executive Order 12866; (3) is “not significant” as defined in DOT’s Regulatory 
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Policies and Procedures; (4) will not have a significant economic impact on a 

substantial number of small entities; (5) will not create unnecessary obstacles to 

the foreign commerce of the United States; and (6) will not impose an unfunded 

mandate on state, local, or tribal governments. 

History 

On October 31, 1994, an Avions de Transport Regional ATR-72 series airplane 

crashed in Roselawn Indiana, resulting in the deaths of 64 passengers and four 

crew members. After an extensive investigation, the National Transportation 

Safety Board (NTSB) concluded that freezing drizzle conditions created a ridge of 

ice on the wing’s upper surface aft of the deicing boots and forward of the 

ailerons. This ridge of ice on the wing contributed to an uncommanded roll of 

the airplane. The atmospheric condition that contributed to the Roselawn 

accident is currently outside the icing envelope for certification of part 25

airplanes. 

On June 1, 2009, an Airbus A330 series airplane operated by Air France crashed 

in the Atlantic Ocean, resulting in the deaths of 216 passengers and 12 crew 

members. After an extensive investigation, the Bureau d'Enquêtes et d'Analyses 

pour la Sécurité de l'Aviation Civile (BEA) concluded that the accident resulted 

from a succession of events: temporary inconsistency between the airspeed 

measurements, probably following obstruction of the pitot tubes by ice crystals, 

that caused the autopilot to disconnect; inappropriate control inputs that 

destabilized the flight path and led to a stall; and the pilot misunderstanding of 

the situation. The atmospheric condition that contributed to this accident is also 

outside the icing envelope for certification of part 25 airplanes. 

We have concluded that these accidents would not have occurred had the 

requirements of this final rule been in affect at the time of the airplane design.
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The current certification requirements for part 25 airplanes and engines do not 

address the safe operation of airplanes in supercooled large drop (SLD), mixed 

phase, or ice crystal icing conditions, and the operating rules do not specifically 

prohibit operations in these conditions. The requirements contained in this final 

rule are based on recommendations by both the NTSB1 and Aviation Rulemaking 

Advisory Committee (ARAC)2, and incorporate the public’s comments from the 

notice of proposed rulemaking (NPRM)3 where appropriate. We estimate the 

benefits and costs associated with certifying designs to these final rule 

requirements in the following sections. 

Regulatory Background

Title 14, Code of Federal Regulations, part 25, part 25 Appendix C, and part 33

specify the certification requirements for airplanes and airplane engines 

operating in icing conditions. Icing conditions containing freezing drizzle and 

freezing rain are currently not considered during certification of an airplane’s ice 

protection systems (IPS). These two conditions constitute an icing environment 

known as SLD. Exposure to these conditions can result in ice accretion that 

impairs the safe operation of a part 25 airplane or airplane engine. This final rule 

will require part 25 airplanes to either safely exit following the detection of

specifically identified appendix O icing conditions, or safely operate without 

restrictions in these SLD conditions. 

 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 Harmonization Working Group (IPHWG).

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Accessible at: 

http://www.regulations.gov/#!docketDetail;dct=FR%252BPR%252BN%252BO%252BSR%252BPS;rpp

=25;so=ASC;sb=docId;po=0;D=FAA-2010-0636
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Similarly, SLD conditions are not currently considered during part 33 engine 

certification. In addition, mixed phase and ice crystal icing conditions are not 

considered for certification of airplane engines or externally mounted probes. 

Exposing engines and externally mounted probes to these conditions can result 

in hazardous ice accumulations that may cause engine damage, power loss, and 

loss of airspeed indication.

The final rule requirements will reduce the risk of accidents by including 

certification requirements for:

(1) SLD icing conditions for part 25 airplanes most affected by these icing 

conditions;

(2) Mixed phase and ice crystal conditions for all part 25 airplanes; and 

(3) SLD, mixed phase, and ice crystal icing conditions for all turbine 

engines installed on part 25 airplanes.

This regulatory evaluation estimates the total incremental benefits and costs of 

the requirements contained in the final rule. Since the NPRM, we have updated 

the fleet, costs and benefits to reflect the most recent data and comments 

submitted. The benefits are based on the expected value of reducing icing 

related accidents. One of the preventable accidents was the 2009 Air France 

A330 accident which we did not quantify in the initial regulatory evaluation as 

the cause had not been determined. Now we know this rule could have 

prevented the sequence of events leading to the 2009 Air France A330 accident. 

We obtained the basis of our cost estimates from industry. The manufacturers 

based their estimates upon accompanying advisory circulars (AC), which 

describe acceptable means for showing compliance. The compliance costs are 

analyzed in context of the new part 25 and part 33 certification requirements. We 

have also re-evaluated the operational costs based upon estimates and analysis 
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from operators who routinely operate part 25 airplanes in SLD environments. 

These costs remain small relative to the substantial benefits.

Assumptions

The benefits and costs are driven by past accidents, industry cost information, 

and the projected future fleet. The benefits are based on past accidents which 

are evaluated as preventable fatalities valued at $9.1 million per prevented 

fatality (2013 Department of Transportation guidance)4, cost of investigation, and 

the value of the airplane. The societal costs include the overhead costs that are 

allocated to labor as well as direct costs. As in the NPRM, we use $77 per hour as 

the burdened wage rate for engineers.5

The fleet forecast affects both the benefits and costs. For purposes of this

evaluation, we conservatively assume that all certifications are approved one 

year after the rule is codified (2014), and that production/deliveries begin to 

occur the following year (2015). The number of deliveries and the corresponding 

delivery years depend on the airplane type and size. We develop and explain

these numbers in the “Fleet” section of this analysis. The production and 

delivery profile created in the “Fleet” section shows a slowly building fleet until 

production stops. Because the production cycles and deliveries are customized 

to the various (and different) airplane types, it is important for the reader to 

focus on present value benefits and costs.

This analysis focuses on the incremental benefits and costs that accrue to U.S. 

operators and manufacturers. We also acknowledge costs to foreign 

 4 "Revised Departmental Guidance 2013: Treatment of the Value of Preventing Fatalities and Injuries in 

Preparing Economic Analyses" http://www.dot.gov/regulations/economic-values-used-in-analysis.

5 Department of Labor; Bureau of Labor Statistics, 2009 mean burdened hourly labor rate of aeronautical 

engineers. Recent BLS data suggests that this burdened hourly labor rate for aeronautical engineers may 

be somewhat overstated, thus the use of the $77/hour figure provides a conservative estimate of the labor 

cost attributable to the rule.
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manufacturers who choose to comply with the requirements contained in this 

final rule by delivering airplanes to U.S. operators.6

To ensure consistency between the costs and benefits of this final rule, these 

values are expressed in 2012 dollars. Current year dollars were adjusted using 

the Bureau of Economic Analysis’ Implicit GDP price deflator.7 For both the 

benefits and the costs, we use a 7% discount rate as prescribed by OMB to reflect 

the time value of money. 

Fleet

This section outlines the methodology which estimates the number of designs, 

production rates, and delivery cycles of airplanes that will be affected by the final 

rule. Our reasoning and the underlying assumptions used in this analysis are 

described below. 

First, we updated the U.S. fleet deliveries to reflect the current year of available 

data (2012). Next, the NPRM regulatory evaluation (RIA) grouped airplanes into 

three categories, small, medium, and large; and then estimated the costs and 

benefits of the small and medium airplane category as one. The RIA for the final 

rule groups the airplanes into two categories; large transport category part 25 

airplanes and all other part 25 airplanes. These two categories are based 

primarily on the size of the airplane. They have been grouped in this way for the 

purposes of estimating the costs and benefits to manufacturers and U.S. 

operators. This methodology differs slightly from the proposed rulemaking 

because we believe this approach improves transparency.

 6 OMB Circular A-4, page 15. 

7 The implicit price deflator is the ratio of nominal GDP over real GDP. The nominal and real GDP values, 

taken from the Bureau of Economic Analysis for 2002 to 2012 and IHS Global Insight Jan 2013 U.S. 

Economic Forecast for 2012, and were originally expressed in 2005$. To express the implicit price 

deflator in in 2012 dollars, we divided the ratio of nominal and real GDP by the 2012 value.
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The large transport category airplanes have a maximum takeoff weight (MTOW) 

greater than or equal to 60,000 pounds and include part 25 turbojet airplanes 

manufactured by Airbus, Boeing, Convair, McDonnell Douglas Aircraft 

Company, and the Lockheed Company. 

The other category approximates business jets, regional jets and turboprops

manufactured by Avions De Transport Regional, Avions Marcel Dassault, Beech

Aircraft Corporation, Bombardier, British Aerospace, British Aircraft 

Corporation, Canadair LTD, Casa, Cessna Aircraft Corporation, Dassault 

Aviation, De Havilland of Canada, Dornier, Embraer, Fairchild, Fokker, 

Grumman Aircraft Corporation, Gulfstream Aerospace Corporation, Hawker

Beechcraft Corporation, Hawker Siddeley Aviation, Israel Aircraft Industry, 

Lear Jet Corporation, Mitsubishi, North American, Raytheon Aircraft Company, 

Rockwell, Saab, and Shorts Brothers.8

We estimate the average life and production run of these U.S.-operated part 25 

airplanes by analyzing the ages of retired airplanes and the airplanes delivery 

schedule using the OAG Aviation Solutions Fleet database. 

Large Transport Category Part 25 Airplane Fleet 

Based upon historical delivery data, this section presents the methodology to 

estimate the average production run, the average life of an airplane, and the 

methodology that generates the affected future newly certificated large transport 

category part 25 fleet. The affected large transport category part 25 airplane fleet 

estimated in this section forms the basis for the benefit and cost analysis.

 8 Duplication results from corporate name changes, mergers or acquisitions.
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To fully account for the life cycle benefits and costs of this part 25 rule, the 

analysis period for large airplanes is based on the life of an airplane plus the 

length of an airplane’s production run. The analysis indicates the average life of 

a large transport part 25 airplane is 28 years and a 19 year production run. The 

resulting analysis period becomes 47 years (19 + 28 = 47). We now discuss the 

derivation of these estimates.

We calculate a weighted average for the average life of U.S.-operated large 

turbojet transport category part 25 airplanes by analyzing the ages of retired 

airplanes operated by part 121 certificate holders using the OAG Aviation 

Solutions Fleet iNet database9 beginning with the Boeing 707 certificated in 

1958.10 To calculate the weighted average, we first multiply the number of 

retired airplanes (by equipment type) by their retirement age. Next, we sum this

series and divide it by the total number of retired airplanes. The results of this 

calculation shows that, on average, U.S. part 121 certificate holders operate their 

airplanes for 28 years before retiring them. Appendix 1 shows the data for this 

calculation.

We estimate the average production run time for newly part 25 certificated 

airplane models by analyzing the start and end delivery dates from U.S. 

operated, out-of-production part 25 (or CAR 4b, which preceded part 25) 

airplanes since 1958. 11 We look at airplanes that are currently out of production 

because a closed production line enables us to account for the number of years of 

 9 http://www.oagaviation.com/, OAG Aviation Solutions Fleet iNet Database - May 2012.

10 In most cases, the retired airplanes were out-of-production, although in some cases, part 121 certificate 

holders retired airplanes still in production.

11

http://active.boeing.com/commercial/orders/index.cfm?content=displaystandardreport.cfm&pageid=m25

062&RequestTimeout=10000 Boeing website (Commercial Airplanes U.S. Delivery Summary By Year) 

- May 2012; http://www.oagaviation.com/ OAG Aviation Solutions Fleet iNet Database - May 2012; 

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFra

meSet FAA Type Certificate Data Sheet database – May 2012.
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airplane production by equipment group. On average, each airplane type was

delivered over a period of approximately 19 years. Appendix 2 shows the start 

and end U.S. delivery dates for the following airplane type: Airbus A300/310; 

Boeing B-707, 720, 727, and 757; Convair CV-880/990; Lockheed L-1011; 

McDonnell Douglas DC-8, DC10/MD11, and DC-9.12

In order to calculate the growth of the affected large transport category part 25 

fleet delivered to U.S. operators, we analyze annual airplane deliveries resulting 

from out-of-production and currently-in-production FAA part 25 transport 

category airplane certifications for U.S. and foreign manufactures.13 Appendix 3 

shows the number of annual airplane deliveries to part 121 certificate holders for 

the following models: Airbus A300, 310, 318, 319, 320, 321,and 330; Boeing B-707, 

720, 727, 737, 747, 757, 767,and 777; Convair CV-880/990; Lockheed L-1011; 

McDonnell Douglas DC-8, DC-9, and DC10/MD11.

Table 1 shows the year that each U.S. manufacturer’s airplane group received its

part 25 type certification (TC), the U.S. deliveries, and years in production from 

1958 to 2011. We believe these models are representative of the industry and use

this data to estimate the number of future certifications and deliveries. 

 12 Note: Each equipment group contains every airplane series along with derivatives. For example, the 

DC-9 equipment group contains every series of DC-9s, MD-80s, MD-90s, and B-717s.

13 Boeing website (Commercial Airplanes U.S. Delivery Summary By Year), OAG Aviation Solutions 

Fleet Database, FAA Type Certificate Data Sheet database.
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TABLE 1 – LARGE TRANSPORT CATEGORY PART 25 U.S. MANUFACTURED 

AIRPLANE TYPE CERTIFICATIONS AND DELIVERIES TO U.S. OPERATORS

Based on Table 1 data we estimate the number of future part 25 large airplane 

certifications and deliveries associated with new large transport category part 25 

certifications (see Table 2 for summary information) over a 10-year certification 

period. 

TABLE 2 - SUMMARY DATA FOR LARGE U.S. MANUFACTURED AIRPLANE 

CERTIFICATIONS

* Details may not add to row or column totals due to rounding.

The historical evidence shows that, on average, U.S. large transport category part 

25 airplane-producing manufacturers receive approval for 0.2 (13 New TCs / 54

Production Years) new airplane type certificates per year, which equates to 

roughly two over a 10-year period. The approximate annual number of U.S. 
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produced large transport category part 25 airplane deliveries to U.S. operators

per type certificate is 27 (7,221 airplanes/271 production years).

Consistent with OMB guidance, a Benefit-Cost Analysis (BCA) conducted on a 

national basis should not consider costs attributed to foreign entities.14 

However, we do estimate the number of foreign part 25 deliveries to U.S.

operators to estimate the added operational costs and the resulting safety 

benefits. Based on past deliveries, Table 3 shows foreign manufacturers will 

deliver 16 large transport category part 25 airplanes annually to U.S. operators. 15

TABLE 3 – LARGE AIRPLANE FOREIGN MANUFACTURED AIRPLANE 

CERTIFICATIONS

Lastly, we add 16 airplanes (produced internationally but delivered to the U.S.) 

to the 27 U.S. produced large transport category part 25 newly certificated 

airplane deliveries estimated above and arrive at 43 annual deliveries from U.S. 

and foreign manufacturers. We use 28 years as the service life and 19 years for 

the average production run time for these newly certificated future airplane 

deliveries (see Table 4).

 14 OMB Circular A94 states “Analyses [BCAs] should focus on benefits and costs accruing to the citizens 

of the United States in determining net present value. Where programs or projects have effects outside 

the United States, these effects should be reported separately.”

15 OAG Aviation Solutions Fleet Database, FAA Type Certificate Data Sheet database, Appendix 3.
14

TABLE 4 – FAA FORECAST OF FUTURE U.S. NEWLY CERTIFICATED LARGE 

TRANSPORT CATEGORY PART 25 AIRPLANE DELIVERIES AND THEIR 

RETIREMENTS
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Other Part 25 Airplane Fleet 

In a similar manner, this section discusses the estimation of the average 

production run and the average life of other part 25 airplanes. This methodology 

generates the affected future newly certificated deliveries for the other part 25 

airplanes not covered in the “Large Transport Category Part 25 Airplane Fleet”

section. To develop the estimated deliveries for these other part 25 airplanes, we

analyzed historical data for the type certifications (TC), production cycles, and 

deliveries for these other part 25 airplanes. 

To fully account for the life cycle benefits and costs of this part 25 rule, the 

analysis period for the other part 25 airplanes is based on the life of an airplane 

plus the length of an airplane’s production run. Based on past history, the 

average life of the other part 25 airplanes is 30 years and has a 15-year horizon 

for the production run of newly certificated airplanes. The analysis period 

begins when the first airplane is delivered and ends when the last airplane from 

the first production is retired. The period of analysis equals 45 years (15 + 30 = 

45). We will now discuss the derivation of these estimates.

We estimate the average life of the U.S.-operated other part 25 airplanes by 

analyzing the ages of retired airplanes using the OAG Aviation Solutions Fleet 

database.16 On average these other part 25 airplanes were operated by U.S. 

operators for 30 years, then retired. We use the same methodology in computing 

a weighted average for the retired other part 25 airplanes as we discussed for the 

large transport category part 25 airplanes. Appendix 5 shows the data for this 

calculation.

 16 http://www.oagaviation.com/, OAG Aviation Solutions Fleet iNet Database - May 2012.
16

We estimate the production run time for other part 25 airplanes by analyzing the 

start and end delivery dates of U.S. operated out-of-production part 25 (or CAR 

4b) airplanes from 1958 to 2011.17 

In order to not introduce bias into estimating the average future certifications

and deliveries, some of the other part 25 airplane models were not included in 

this analysis because only a small number of airplanes from these models were 

delivered to U.S. operators over only a couple of years and this would have 

biased the averages. These are airplane models with only a few U.S. deliveries, 

such as: the Canadair C-44, DeHavilland DHC-7, Fokker F-28, IPTN CN-235, 

British Aerospace 146 and 4100, and Dornier 328 turboprop and turbojets. 

After removing these airplanes, we estimate, on average, the other part 25

airplane production run time was approximately 15 years. We use the same 

methodology in estimating the production run time for other part 25 airplanes as 

we discussed above for the large transport category part 25 airplanes. Appendix 

6 shows the start and end delivery dates of the out-of-production other part 25 

U.S. airplane deliveries used in the 15 year calculation.

In order to calculate the growth of the affected fleet of other part 25 airplanes 

delivered to U.S. operators, we analyze annual airplane deliveries resulting from 

all (out-of-production and currently-in-production) airplane certifications for 

U.S. and foreign manufactures.18 Appendix 7 shows the number of annual other 

part 25 airplane deliveries to U.S. operators. As mentioned above, in order to not 

introduce bias into estimating the future affected fleet for this analysis, we have 

removed the sparsely-delivered airplanes from the delivery of other part 25 

airplane calculation.

 17 OAG Aviation Solutions Fleet Database, FAA Type Certificate Data Sheet database.

18 Ibid.
17

Table 5 shows the year that U.S. manufacturer’s airplane group received their 

part 25 type certification, the U.S. deliveries, and years in production from 1959

to 2011.19 We use this data to estimate the number of future certifications and

deliveries associated with a new part 25 certification for the other airplanes. 

TABLE 5 – OTHER U.S. MANUFACTURED AIRPLANE CERTIFICATIONS

Table 6 summarizes the data from Table 5 to estimate the number of future other 

part 25 airplane certifications and deliveries associated with new other part 25 

certifications over a 10-year certification period. 

TABLE 6 - SUMMARY DATA FOR OTHER U.S. MANUFACTURED AIRPLANE 

CERTIFICATIONS

* Details may not add to row or column totals due to rounding.

 19 Due to the extensive mergers and acquisition history of the other part 25 airplane manufacturers; we 

determined a U.S. manufacture by their headquarters being located within the U.S.
18

The historical evidence shows that, on average, the other U.S. part 25 airplaneproducing manufacturers receive approval for 0.2 (12 New TCs / 53 Years) new 

airplane type certificates per year, which equates to roughly two over a 10-year 

period. The approximate annual number of U.S.-manufactured other part 25

airplane deliveries to the U.S. operators per type certificate is 21 (6,904

airplanes/328 production years).

As discussed above, we do not estimate the certification cost to foreign 

manufacturers, but we do need to estimate the number of foreign deliveries to 

U.S. operators for the benefit and cost impact. Table 7 shows foreign 

manufacturers will deliver 12 other part 25 airplanes annually to U.S. operators.20

TABLE 7 – OTHER FOREIGN MANUFACTURED AIRPLANE CERTIFICATIONS

* Details may not add to row or column totals due to rounding.

 20 OAG Aviation Solutions Fleet Database, FAA Type Certificate Data Sheet database, Appendix 7.
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Lastly, we add 12 airplanes (produced internationally but delivered to the U.S.) 

to the 21 other parts 25 newly certificated future airplane deliveries and arrive at 

33 annual deliveries from U.S. and foreign manufacturers. We use 30 years as 

the other part 25 airplane service life and 15 years for the average production run 

time for these newly certificated future other part 25 airplane deliveries. Table 8

shows these results.

TABLE 8 – FUTURE OTHER PART 25 AIRPLANE DELIVERIES TO THE U.S.
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Benefits

Accidents in icing conditions tend to be associated with stalls, loss of control, and 

catastrophic outcomes. The purpose of this final rule is to prevent such 

outcomes in the future. Without a new rule, it is likely that future icing related 

accidents will occur on part 25 airplanes similar to what has happened in the 

past. The industry and the FAA analyzed the historical icing related events for 

airplanes certificated under part 25 and engines certificated under part 33. The 

FAA evaluated all events (accidents plus incidents) for applicability and 

preventability in context with the requirements contained in this final rule. An 

event is defined as an accident or incident that could have been prevented had 

the requirements in this final rule been in effect during the certification process.

The FAA describes each event, provides the basis for benefits, and estimates the 

probability of a future event for three categories of benefits that directly align 

with the requirements. 

• Benefits from averting events involving large transport category part 

25 airplanes,

• Benefits from averting events involving other part 25 airplanes, and

• Benefits from averting part 33 engine events.

Benefits from Averting Large Transport Category Part 25 Airplane Events

Based on previous in-service experience, SLD poses a smaller risk to large 

transport category part 25 airplanes, when compared to smaller, other transport 

category part 25 airplanes. Due to the lower risk, the FAA has removed the 

requirements proposed in the NPRM for large airplanes to demonstrate 

performance and handling in Appendix O SLD conditions. The final rule will 

only include system design requirements for large transport category part 25 

airplanes. Although large airplanes have less risk in SLD, an accident to a large 

transport category airplane did occur following operation in ice crystal icing 

conditions, and could have been prevented by this rule. On June 1, 2009, an Air 
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France A330 crashed. Two hundred and twenty eight people died and the 

airplane was destroyed.

On July 5, 2012, France’s aviation accident investigation bureau (BEA) released 

its final report for this accident. According to the BEA, the accident resulted 

from a succession of events that began with “Temporary inconsistency between 

the measured airspeeds, likely following the obstruction of the pitot probes by 

ice crystals that lead in particular to autopilot disconnection and a 

reconfiguration to alternate law,” and “inappropriate control inputs that 

destabilized the flight path”.21

The benefit analysis for this rule is based on the fact that large transport category 

part 25 airplanes have a positive risk of an icing event. This section of the benefit 

analysis discusses the FAA’s quantitative estimate for preventing an accident like 

the Air France A330 accident on future newly certificated large transport 

category part 25 U.S.-operated airplanes. Appendix 4 shows our estimate of the 

total expected benefits for newly certificated large transport category part 25 U.S.

operated airplanes. While the historical lives and property loss are a public 

record, determining the rate of future annual risk is subject to a wide range of 

possible outcomes. However, given the catastrophic A330 accident, all mitigated 

outcomes have substantial potential benefits. Appendix 4 shows the present 

value when we estimate benefits with the date the A330 accident occurred and 

spread this risk over the future United States fleet. We now discuss the 

derivation of the final rule benefits for large transport category airplanes.

In the NPRM the FAA discussed the Air France A330 accident, but did not 

include this accident in the quantified benefit analysis. Upon further review and 

 21Final BEA Report,http://www.bea.aero/en/enquetes/flight.af.447/flight.af.447.php.
22

with more information from the BEA final report of the accident, the FAA now 

believes this rule would prevent a similar accident from occurring in U.S. 

operations. The Air France A330 accident likely occurred because of an icing 

obstruction in the pitot tubes causing the cockpit instruments to malfunction. 

The crew apparently had difficulty understanding the malfunctioning 

instruments which led to an improper response and ultimately resulted in the 

catastrophic accident. The sequence of events leading to the accident began with 

icing in a pitot tube which this final rule will resolve. This final rule adds new 

SLD, mixed phase, and ice crystal requirements for pitot tubes.

All large part 25 airplanes have pitot tubes, which have not been qualified to 

operate in the ice crystal and mixed phase conditions described in part 33, 

Appendix D of this final rule. While this accident did not occur to a U. S.

operator, currently there are about 5,000 large part 25 airplanes flown by U.S. 

part 91, 135, and 121 operators.22 The FAA expects that accidents similar to the 

2009 A330 will continue to occur on large part 25 airplanes unless this final rule 

is in effect. 

We now discuss the component benefit of an averted accident which forms the 

quantitative bases for future benefits.

In estimating benefit values for avoided fatalities and injuries, the FAA follows 

the Department of Transportation’s (DOT) recently-issued document “Revised 

Departmental Guidance 2013: Treatment of the Value of Preventing Fatalities 

and Injuries in Preparing Economic Analysis.” That document estimates the 

value for preventing a fatality in 2012 at $9.1 million (in 2012 dollars), while 

preventing a serious injury in 2012 is valued at $1,264,900 (assumed to be the 

 22 http://www.oagaviation.com/, OAG Aviation Solutions Fleet iNet Database - May 2012.
23

average of economic costs for severe, serious, and moderate injuries), and 

preventing a minor injury in 2012 is estimated to have an economic value of 

$27,300. As recommended in the recent DOT guidance document identified 

above, these values are then escalated at 1.07 percent per year to reflect the effect 

of growth in real income levels on the value that society collectively places on 

avoiding accidental fatalities and injuries. 23 See Appendix 9 for more details.

The FAA estimated the average airplane replacement for a destroyed large part 

25 two-engine wide body at the airplane’s weighted average market value of 

$46.3 million.24 The BEA accident investigation reports provided the number of 

fatalities. The FAA estimates the average value of avoiding an icing-related

accident, where a large transport category part 25 A330 airplane is destroyed, to 

be about $2.1 billion. 

We believe this final rule could have prevented a similar large part 25 airplane

accident in the U.S. Further, we expect future accidents in conditions conducive 

to icing could also occur. Herein, the methodology is presented to substantiate 

the basis for increasing the value of preventing icing related accidents that could 

occur over the analysis interval to all newly certificated large transport category 

part 25 U.S. operated airplanes in the absence of the final rule: 

1. Based on the casualty losses from the 2009 A330 accident, we calculate 

three separate accident and casualty rates. These accident and casualty rates are 

calculated by dividing the total losses per category (fatality, investigation and 

 23 "Revised Departmental Guidance 2013: Treatment of the Value of Preventing Fatalities and Injuries in 

Preparing Economic Analyses" http://www.dot.gov/regulations/economic-values-used-in-analysis

24 Aircraft values used in the analysis are estimated per the discussion found in Appendix 8 and are 

subsequently expressed in 2012$.
24

airplane accident) from the 2009 A330 accident by the total number of large 

transport category part 25 airplanes delivered worldwide from 1998 - 2011. 25 

The results of this derivation are exhibited in Table 4-1 in Appendix 4. 

2. The historical accident and casualty rates calculated in step 1 are 

multiplied by the annual number of projected newly certificated large transport 

category part 25 affected U.S. operated deliveries from 2015 through 2060. Table 

4 above shows that 43 newly certificated large transport category part 25 

airplanes will be delivered annually to U.S. operators. We use 28 years as the 

airplane’s service life and 19 years for the average production run time for these 

newly certificated airplane deliveries. 

3. After totaling the estimated number of future accidents and casualties 

over the analysis period, we use the averted event values discussed above, and 

shown in Appendix 9, to quantify the total potential benefits of the final rule. 

The FAA estimates that the total benefits of avoiding one large transport 

category part 25 airplane accident from newly certificated deliveries over the 

2015 through 2060 analysis interval are shown in Table 9. The details are shown 

in Table 4-2 in Appendix 4.26 

 25 OAG Aviation Worldwide Inc.’s Fleet data product shows 1998 as the first A330 delivery.

26 The FAA notes that we rounded up the value of the number of investigations and accidents but used the 

quantified fractional value to quantify these benefits.
25

TABLE 9 – ESTIMATED BENEFITS – 2012 $

* Details may not add to row or column totals due to rounding.

Although the FAA is not aware of any other accidents of this type involving 

other large part 25 transport category airplanes, there is no reason to believe that 

the risk of such accidents is limited to Airbus airplanes. 

Benefits from Averting Other Part 25 Airplane Events

The FAA now examines historical related SLD events for the other part 25 

airplanes. Based on past accidents the accident risk to the other part 25 airplanes 

is higher than the large category transport airplanes. The FAA includes some 

basic information on each accident and the justification for applicability. Since 

the NPRM, there has been a final report issued on another preventable icingrelated event and accordingly, this event has been added. 

1) Embraer 120 Accident

NTSB Identification: FTW93MA143

Event Description: On 4/29/1993 an Embraer EMB-120 was substantially 

damaged when it collided with rough terrain during an overrun following a 

forced landing. The forced landing was executed following a stall and loss of 
26

control at 17,412 feet during climb, which resulted in damage to the left engine 

and propeller. Thirteen individuals received minor injuries.

Probable Cause: The NTSB found that, in combination with other factors, ice 

accretion led to an aerodynamic stall, loss of control, and a forced landing. 

Justification for Revised Rule Applicability: The meteorological report indicated 

the possibility of SLD icing in the area of this accident. 14 CFR 25.1420 will 

require a means of detecting appendix O conditions for which the manufacturer 

has not certificated the airplane and will also require that the airplane be capable 

of operating safely within those conditions for the purpose of exiting when 

conditions are encountered which are beyond which the airplane has been 

certified.

2) ATR-72 Accident

NTSB Identification: DCA95MA001.

Event Description: On 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 fatalities.

Probable Cause: The NTSB found that the probable cause of the accident was the 

loss of control, attributed to a sudden and unexpected aileron hinge moment 

reversal that occurred after a ridge of ice accreted aft of the deice boots while the 

airplane was in a holding pattern. The airplane intermittently encountered 

supercooled cloud and drizzle/rain drops, the size and water content of which 

exceeded those described in the icing certification envelope. 
27

Justification for Revised Rule Applicability: The stall and loss of control after 

encountering large droplet icing conditions may have been consistent with 

appendix O. 14 CFR 25.1420 will require the airplane to be able to safely operate 

in appendix O conditions or have a means of detecting appendix O conditions 

and be capable of operating safely within those conditions for the purpose of 

exiting when conditions are encountered which are beyond which the airplane 

has been certified.

3) Cessna 560 Accident

NTSB Identification: CHI96FA067.

Event Description: On 12/30/1995 two fatalities occurred as a result of a Cessna 

560 colliding with the terrain at the Eagle River Airport, Eagle River, Wisconsin. 

Although the ice accretion was not described as consistent with large droplet 

icing, a sheriff’s deputy reported freezing rain and sleet were falling at the time 

of the accident. 

Probable Cause: The NTSB determined the probable cause of the accident was 

the failure of the pilot to maintain airspeed while executing the circling 

approach. Factors were the descent below minimum descent altitude, the fog, the 

low ceiling and the icing conditions.

Justification for Revised Rule Applicability: Existing airplanes have not 

substantiated that they are capable of safely operating in appendix O (freezing 

drizzle and freezing rain) conditions. 14 CFR 25.1420 will require the airplane be 

able to safely operate in appendix O conditions or have a means of detecting 

appendix O conditions and be capable of operating safely within those 
28

conditions for the purpose of exiting when conditions are encountered which are 

beyond which the airplane has been certified.

The FAA notes that during the comment period, the validity of this accident in 

the benefit analysis was brought into question because the stall warning system 

of the Model 560 has since been modified to provide greater stall warning 

margin in icing. The FAA reviewed the request and we determined that the 

Cessna Model 560 Eagle River event should be included in the benefit analysis 

because this rule will require that the new conditions (SLD) be considered when 

designing the stall warning system, as well as other systems, to ensure the 

airplane can be safely operated following encounters with SLD conditions.

4) Embraer 120 Accident

NTSB Identification: DCA97MA017

Event Description: On 01/09/1997 an Embraer EMB-120RT crashed while being 

vectored for approach to runway 3R at Detroit Metropolitan Wayne County 

Airport, which resulted in 29 deaths. 

Probable Cause: The NTSB attributes the probable cause to the FAA’s failure to 

establish adequate aircraft certification standards for flight in icing conditions, 

the FAA's failure to ensure that FAA-approved procedures were implemented at 

Centro Tecnico Aeroespacial for the accident airplane's deice system operation, 

and the FAA's failure to require the establishment of adequate minimum 

airspeeds for icing conditions, which led to the loss of control when the airplane 

accumulated a thin, rough, accretion of ice on its lifting surfaces. Contributing to 

the accident were the flightcrew's decision to operate in icing conditions near the 

lower margin of the operating airspeed envelope (with flaps retracted) and 

Comair's failure to establish and adequately disseminate unambiguous 
29

minimum airspeed values for flap configurations and for flight in icing 

conditions.

The investigation revealed that it was likely that the airplane gradually 

accumulated a thin, rough glaze/mixed ice coverage on the leading edge deicing 

boot surfaces, possibly with ice ridge formation on the leading edge upper 

surface. 

The NTSB determined one of the probable causes was the failure to establish 

adequate airplane certification standards for flight in icing conditions.

Justification for Revised Rule Applicability: Existing airplanes have not 

substantiated that they are capable of safely operating in appendix O (freezing 

drizzle and freezing rain) conditions. 14 CFR 25.1420 requires newly certificated 

airplanes safely operate in appendix O conditions or have a means of detecting 

and exiting appendix O conditions.

5) Embraer 120 Accident

NTSB Identification: DCA01MA031

Event Description – The accident occurred on 3/19/2001 which resulted in 

neither deaths nor injuries. 

Probable Cause: The NTSB determined the cause of the accident as the failure of 

the flight crew to maintain airspeed during an encounter with severe icing 

conditions, which resulted in an inadvertent stall, loss of control, and structural 

damage to the airplane.
30

Justification for Revised Rule Applicability: The airplane encountered SLD icing. 

The flightcrew delayed exiting the conditions. This final rule will require a 

means of detecting appendix O conditions for which the manufacturer has not 

certificated the airplane. It will further require that the airplane be capable of 

operating safely within those conditions for the purpose of exiting when 

conditions are encountered which are beyond which the airplane has been 

certified.

6) Jetstream 41 Event 

Event Description: On 1/24/05 the flight declared an emergency due to an icing 

condition that would not allow the airplane to maintain altitude. The emergency 

landing did not result in fatalities or injuries. 

Justification for Revised Rule Applicability: The icing conditions exceeded the 

capabilities of the airplane and appendix O defines conditions (freezing drizzle 

and freezing rain) that are more severe than current certification standards. 14

CFR 25.1420 will require that newly certificated airplanes safely operate in 

appendix O conditions or have a means of detecting and exiting appendix O 

conditions.

7) SAAB-340 Incident

NTSB Identification: LAX06IA076

Event Description: On 1/2/2006 the flight encountered icing conditions. The 

airplane was at 11,700 feet mean sea level (msl) when it departed controlled 

flight, and descended to an altitude of about 6,500 feet msl. The pilots recovered 

control of the airplane, and continued to their scheduled destination. The two
31

flight crew members, one flight attendant, and 25 passengers were uninjured, 

and the airplane did not sustain substantial damage.

Probable Cause: An in-flight loss of control due to ice accreted in SLD conditions, 

and the flight crew's failure to maintain the specified minimum airspeed in icing 

conditions. Contributing to the accident was the flight crew's decision to climb 

the airplane in known and forecast icing conditions using an autopilot mode 

contrary to that specified in the operator's Airplane Operations Manual for 

climbs during periods of ice accretion or when ice was present on the airframe.

Justification for Revised Rule Applicability: Reports have shown that there were 

icing conditions present which likely exceeded those for which the airplane was 

originally certificated. Had the airplane been certified in accordance with this 

final rule, it would have had a means of detecting appendix O conditions and 

would have been capable of either operating safely within those conditions or 

exiting when conditions are encountered which are beyond which the airplane 

has been certified.

8) ATR 42-320 Accident 

NTSB Identification: CEN09MA142

Event Description: On 1/27/09 Avions de Transport Régional ATR 42 320, 

N902FX, operating as Empire Airlines flight 8284, was on an instrument 

approach when it crashed short of the runway at Lubbock Preston Smith 

International Airport, Lubbock, Texas. The captain sustained serious injuries, 

and the first officer sustained minor injuries. The airplane was substantially 

damaged. The airplane was registered to Federal Express Corporation and 

operated by Empire Airlines, Inc., as a 14 Code of Federal Regulations Part 121 

supplemental cargo flight. The flight departed from Fort Worth Alliance Airport, 
32

Fort Worth, Texas, about 0313. Instrument meteorological conditions prevailed, 

and an instrument flight rules flight plan was filed.

Probable Cause: The flight crew's failure to monitor and maintain a minimum 

safe airspeed while executing an instrument approach in icing conditions, which 

resulted in an aerodynamic stall at low altitude. Contributing to the accident 

were 1) the flight crew's failure to follow published standard operating 

procedures in response to a flap anomaly, 2) the captain's decision to continue 

with the unstabilized approach, 3) the flight crew's poor crew resource 

management, and 4) fatigue due to the time of day in which the accident 

occurred and a cumulative sleep debt, which likely impaired the captain's 

performance.

Justification for Revised Rule Applicability: It has not been substantiated that 

existing airplanes are capable of safely operating in freezing rain and freezing 

drizzle as described in appendix O. This final rule will require that airplanes be 

capable of safe operation in appendix O conditions or have a means of detecting 

appendix O conditions and safely exiting when conditions are encountered 

which are beyond which the airplane has been certified. 

Table 10 summarizes the above other part 25 airplane events and their fatalities 

and injuries.

TABLE 10 - OTHER PART 25 AIRPLANE ACCIDENTS
33

As shown in the above historical events, SLD accidents tend to be associated 

with stalls, loss of control, and catastrophic outcomes. We examined these

historical events that could have been prevented with the requirements in this 

final rule. We acknowledge that some SLD events have not resulted in passenger 

deaths. However, narrowly averting a catastrophic SLD event with an airplane 

that has not been certified to the appropriate standards in this final rule puts 

passengers and crew at risk. 

FAA icing certification experts also estimate the risk of an accident on other part 

25 airplanes is positive. We now discuss the component benefit of an averted 

accident on other part 25 airplanes.

The benefit of avoiding an accident includes averted fatalities, injuries, aircraft 

replacement or repair, and accident investigation costs. To estimate benefit 

values, the FAA uses the same fatality values, injury values, and accident 

investigation costs as we did for large transport category part 25 airplanes above. 

The FAA estimated the average airplane replacement for a destroyed other part 

25 at the airplanes weighted average market value of about $9.2 million. 27 The

NTSB accident investigation reports provided the number of fatalities and 

injuries. The FAA estimates the average value of avoiding an icing-related 

accident, where the airplane is destroyed, to be about $122.2 million. Table 11

shows the results of this calculation.

 27 Aircraft values used in the analysis are estimated per the discussion found in Appendix 8 and are 

subsequently expressed in 2012$.
34

TABLE 11 – AVERAGE BENEFIT OF PREVENTING ONE SLD ACCIDENT TO 

AN OTHER PART 25 AIRPLANE

* Details may not add to row or column totals due to rounding.

We believe this final rule could have prevented similar icing-related accidents on 

other newly certificated part 25 airplanes in the U.S. Further, we expect future 

accidents in conditions conducive to icing to also occur. Herein, the 

methodology is presented to substantiate the basis for increasing the value of 

preventing icing related accidents that could occur over the analysis interval to 

other part 25 airplanes in the absence of the final rule: 

1. Based on the 1993-2009 casualty losses listed in table 10, we calculate three 

separate accident and casualty rates. These accident and casualty rates were 

calculated by dividing the average losses per category (fatality, investigation and 

accident) by the average number of other part 25 airplanes operating in the U.S. 

since 1993.28 The results of this derivation are exhibited in Table 12.

 28 We use the average number of other part 25 airplanes operating in the U.S. because all of the events on 

other part 25 airplanes occurred in the U.S.
35

TABLE 12 – DERIVATION OF ACCIDENT AND CASUALTY RATES

2. The historical accident and casualty rates, calculated in step 1, are 

multiplied by the annual number of projected affected other U.S.-operated part 

25 future deliveries from 2015 through 2058. Table 8 above shows that 33 other

part 25 airplanes will be delivered annually to U.S. operators. We use 30 years as 

the service life and 15 years for the average production run time for these newly 

certificated airplane deliveries as discussed in the “Fleet” section above. 

3. After totaling the estimated number of future accidents and casualties 

over the analysis period, we use the accident event values from Table 11 to 

quantify the total potential benefits of the final rule. 

Table 13 shows the benefit calculations, estimated from 2015 to 2058, produce 

approximately one avoided accident with 18 fatalities and two minor injuries on 

newly certificated other part 25 airplanes. 
36

TABLE 13 – DERIVATION OF BENEFITS FOR OTHER PART 25 AIRPLANES

* Details may not add to row or column totals due to rounding.

Benefits from Averting Engine Events

As examined in the NPRM, from 1988-2003, there were over 100 documented 

cases of ice crystal and mixed phase engine power loss events. These events are 

directly related to the engine requirements contained in this final rule. Of these 

events, there were eleven total power loss events from flameouts.29 The FAA 

views these events as accident precursors. One of the events occurred when a 

Beechjet 400, with PWC JT15D engines, had a total power loss at top-of-descent 

 29 Total power loss events are events where all engines lose power at the same time.
37

and could not relight the engines. That event resulted in a dead-stick forced 

landing at Jacksonville airport. Having engines flameout during a flight is a 

serious event, which can result in an accident. The FAA has examined these 

historical events and has found that they resulted in about a 12% diversion rate.30 

Similar to the other design requirements contained in the final rule, we have 

included five of the most significant recent events and include some basic 

information on each event and the justification for applicability. Each of these 

events would have been mitigated by the part 33 requirements contained in this 

rule had they been in affect at the time of certification.31 We did not include 

engine damage events where power loss did not occur, but there was core 

damage. We believe these damage costs will be averted once the final rule is

effective. 

1) Beechjet Incident

NTSB Identification: ENG04IA021

14 CFR 91: General Aviation

Incident occurred Monday, July 12, 2004, in Sarasota, FL

Probable Cause Approval Date: 12/20/2007

Airplane: Raytheon Corporate Jets Beechjet 400A, registration: N455CW

Note: Continued Airworthiness Assessment Methodologies (CAAM) 332 due to 

loss of >3k feet with both engines out.

 30 FAA Engine and Propeller Directorate- The 12% diversion 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.

31 Part 33 focuses on mixed phase and ice crystals as the new feature, in addition to having a ground based 

icing test that includes SLD. In addition to the events listed, there are also unscheduled landings that are 

preventable with the requirements. The FAA conservatively does not estimate these additional benefits,

but notes that operators will realize cost savings whenever these events are averted. 

32 CAAM ENGINE HAZARDOUS LEVEL 3 - SERIOUS CONSEQUENCES

a. Substantial damage to the aircraft or second unrelated system. 
38

See NTSB web site for narrative:

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20040804X01143&key=1

Event Description: The Hawker-Beech Beechjet 400A was descending through 

flight level 390 when both of the engines flamed out and lost all power while 

operating in instrument meteorological conditions with convective storms in the 

area. The pilots, after several attempts, were able to get one engine restarted as 

the airplane was descending through 10,000 feet and diverted to a nearby airport. 

High-altitude ice crystals had accreted on the compressor vanes and were 

ingested into the high pressure compressor when the pilots retarded the power 

levers causing compressor surges and flameouts of both engines.

Justification for Revised Rule Applicability: Revisions to 14 CFR 33.68 will 

require turbine engines to demonstrate acceptable and safe operation in the

mixed phase and ice crystal icing environment of part 33, appendix D.

2) Beechjet Incident

NTSB Identification: DCA06IA007. 

14 CFR 91: General Aviation

Incident occurred November 28, 2005, in Jacksonville, FL

Probable Cause Approval Date: 6/30/2008

Airplane: Raytheon Corporate Jets Beechjet 400A, registration: N691TA

Note: CAAM 433 due to forced landing with both engines out.

 

b. Uncontrolled fires.

c. Rapid depressurization of the cabin. 

d. Permanent loss of thrust or power greater than one propulsion system. 

e. Temporary or permanent inability to climb and fly 1000 feet above terrain. 

f. Any temporary or permanent impairment of aircraft controllability.

g. Malfunctions or failures that result in smoke or other fumes, delivered through the ECS system that 

result in a serious impairment.

33 CAAM ENGINE HAZARDOUS LEVEL 4 - SEVERE CONSEQUENCES 

a. Forced landing. 

b. Loss of aircraft (hull loss). 
39

See NTSB web site for narrative:

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20060104X00004&key=1

Event Description: The Hawker-Beech Beechjet 400A was descending through 

flight level 380 in visual meteorological conditions in the vicinity of 

cumulonimbus buildups. Upon reducing power to initiate descent the crew 

heard a “popping” noise, and both engines rolled back. The crew declared an 

emergency, elected to divert to Jacksonville airport, and initiated emergency 

procedures. All attempts to restart the engines were unsuccessful. The crew 

executed a successful emergency dead-stick landing.

Justification for Revised Rule Applicability: Revisions to 14 CFR 33.68 will 

require turbine engines to demonstrate acceptable and safe operation in the 

mixed phase and ice crystal icing environment of part 33, appendix D.

3) Beechjet Incident

NTSB Identification: ENG06IA020. 

14 CFR 91: General Aviation

Incident occurred Wednesday, June 14, 2006, in Norfolk, VA

Probable Cause Approval Date: 1/31/2008

Airplane: Raytheon Corporate Jets Beechjet 400A, registration: N440DS

Note: CAAM 3 due to loss of >3k feet with both engines out.

See NTSB web site for narrative:

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20060712X00929&key=1

Event Description: The Raytheon 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 anti-ice systems. The airplane was in visual 

meteorological conditions, but was approaching clouds that were known to 

contain remnants of a tropical storm. The left and right engines restarted on 

 

c. Serious injuries or fatalities.
40

their own as the airplane descended through flight levels 300 and 240, 

respectively.

Justification for Revised Rule Applicability: Revisions to 14 CFR 33, § 33.68 will

require turbine engines to demonstrate acceptable and safe operation in the 

mixed phase and ice crystal icing environment of part 33, appendix D.

4) MD-82 Incident 

NTSB Identification: CHI02IA151. 

Scheduled 14 CFR 121: Air Carrier SPIRIT AIRLINES INC.

Incident occurred Tuesday, June 4, 2002, in Wichita, KS

Probable Cause Approval Date: 1/28/2005

Airplane: McDonnell Douglas MD-82, registration: N823NK

Note: CAAM 3 due to loss of >3k feet with both engines out.

See NTSB web site for narrative:

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20020612X00866&key=1

Event Description: The airplane experienced a roll back of engine power on both 

engines and subsequently stalled while in cruise flight at flight level 330. The 

weather conditions were consistent with the presence of ice crystals at the cruise 

altitude. The engine inlet probes became blocked due to the ice crystals,

resulting in a false engine pressure ratio (EPR) indication and subsequent 

retarding of the throttles by the auto-throttle system. The NTSB stated that 

factors included the presence of ice crystals at altitude, and the icing of the 

engine inlet probes resulting in a false engine pressure ratio indication.

Justification for Revised Rule Applicability: Engine inlet probes and engine inlet 

systems are addressed in the revisions to 14 CFR 33.68, which will require 

turbine engines to demonstrate acceptable and safe operation in the mixed phase 

and ice crystal icing environment of part 33, appendix D.
41

In addition on January 5, 2004, a Fokker 70 accident occurred near Munich 

(Germany) Airport, causing three minor injuries and severe airplane damage 

after a prolonged exposure to moderate mixed phase icing conditions. 

The continued incidents, accidents, diversions, and power losses demonstrate the 

need for the engine requirements in this final rule. The above events are 

precursor events that, if not addressed through rulemaking, could result in an 

unrecoverable power loss and consequent fatal accident. 

Benefit Summary

Table 13 shows the other part 25 airplane benefits for both the nominal and 

present value cases. Similarly, Appendix 4 shows the large part 25 transport 

category airplane benefits. In the “Benefits from Engine Requirements” section, 

we discuss qualitative benefits for engines. Table 14 summarizes these results.

TABLE 14 - SUMMARY OF BENEFITS

* Details may not add to row or column totals due to rounding.

Costs

This section provides the estimated incremental societal costs for the United 

States that will result from the requirements contained in this final rule. 

Accordingly, we estimate costs to U.S. manufacturers and to U.S. operators. 

International manufacturer costs are not included in the overall compliance costs

of this regulation because these costs are not incurred in the United States. 

The total estimated costs of this final rule are $61.3 million ($42.3 million present 

value). This section discusses how these costs are developed. We first discuss 

the final rule revisions and new regulations to part 25 and 33. Next we discuss 
42

the cost-related industry comments to the NPRM and the changes the FAA has 

made, based on those comments, to the final rule. Then, we estimate the fixed 

(certification) costs and recurrent (fuel) costs to part 25 large transport category 

airplane manufacturers and operators. Next, we estimate the fixed costs and 

recurrent costs to the other part 25 airplane manufacturers and operators. The 

FAA defined the large part 25 transport category airplanes and the other part 25

airplanes in the “Fleet” section above. Lastly, we analyze the additional costs for 

engine certification and hardware. 

We incorporate manufacturer cost estimates detailing certification and testing 

costs and, where appropriate, we incorporate changes in the costs of compliance 

as a result of the public comments to the NPRM. For the analysis, the 

manufacturer-estimated costs were adjusted for inflation, our assumptions, and 

the specified labor rates.

The FAA is adopting this final rule to revise certain regulations in Title 14, Code 

of Federal Regulations (14 CFR) part 25 (Airworthiness Standards: Transport 

Category Airplanes) and part 33 (Airworthiness Standards: Aircraft Engines) 

related to the certification of transport category airplanes and turbine engines in 

icing conditions. 

To improve the safety of part 25 transport category airplanes operating in 

supercooled large drop (SLD), mixed phase, and ice crystal icing conditions, 

these regulations will: 

• Require airplanes most affected by large drop icing conditions to 

meet certain safety standards in an expanded certification icing environment 

that includes freezing drizzle and freezing rain. These safety standards 

include airplane performance and handling quality requirements.
43

• Expand the engine and engine installation certification, and some 

airplane component certification regulations (for example, angle of attack and 

airspeed indicating systems), to include freezing drizzle, freezing rain, mixed 

phase and ice crystal icing envelope (deep convective clouds).

Several commenters to the NPRM stated that available engineering tools (icing 

wind tunnels and tankers, ice accretion prediction codes, and other analysis 

methods) are inadequate for showing compliance with the new rule. The FAA 

recognizes that the current engineering tools available to show compliance with 

the new SLD rule have not been validated in every aspect and have some 

limitations. At the request of industry members of the Aviation Rulemaking 

Advisory Committee, the Ice Protection Harmonization Working Group 

(IPHWG) evaluated the current capabilities of these tools during a review in 

2009. The FAA recognizes that reliance upon available simulation methods 

combined with engineering judgment will be required for finding compliance 

with these final requirements. For freezing rain conditions, engineering 

judgment may allow for other methods of compliance, even though not 

validated, when used in a fashion similar to that recommended for freezing 

drizzle. In February 2012, Flight Global reported that EADS recently opened a 

dedicated cryogenic wind tunnel for anti-icing studies. The wind tunnel has the 

capacity to investigate the crystallization process of supercooled liquid droplets 

and find ways to minimize in-flight ice buildup.34 The FAA concludes that even 

with the limitations to the engineering tools, there is enough capability to 

demonstrate compliance to the new and revised requirements of this final rule. 

The FAA has concluded that analytical methods used to determine SLD ice 

accretions on radomes have shown considerably higher ice mass accretions than 

 34 http://www.flightglobal.com/news/articles/eads-opens-dedicated-cryogenic-windtunnel-for-anti-icingstudies-367673/.
44

past experience has indicated for other icing conditions. For the § 25.1093 

compliance of affected airplanes, analysis may be used for the radome as a 

potential airframe ice source. Applicants may use qualitative analysis of the 

design supported by similarity to a previous design that has shown successful 

service history to demonstrate confidence that the historical methodology for 

certification is appropriate. 

Some commenters questioned the validity of the high costs to large airplanes and 

their low risk due to the large droplet icing accident history. The FAA requested 

clarification of these comments from the manufacturers of large airplanes. In 

response, the FAA eliminated future newly part 25 certificated large airplanes 

from considering Appendix O SLD conditions for compliance with the § 25.1093 

NPRM engine induction system ice protection requirements. This action 

significantly reduced the fixed system design certification costs of this final rule 

and the recurrent fuel costs to newly certificated large transport category part 25 

airplanes.35 While large airplanes will not need to consider Appendix O SLD

conditions for compliance with engine inlet or performance and handling 

requirements, the final rule will still add some costs due to system design 

certification requirements for newly certificated large part 25 airplanes delivered 

to the U.S.

We now discuss the costs to the large transport category part 25 airplane 

manufacturers. 

Large Transport Category Part 25 Airplane Certification Costs

During the comment period, we received comments from large airplane

manufacturers that claimed an additional cost not included in the NPRM RIA. 

The industry cost estimates were partially based on assumptions that an ice 

 35 § 25.1093(b)(3).
45

protection system was required for the radome and an accompanying change to 

the ice detection system would be necessary. We do not agree with the 

assumption that either a radome ice protection system is required or that changes 

to an ice detection system are necessary in consideration of the icing conditions 

defined in part 25, appendix O for large airplanes. As such, the cost estimates of

a radome ice protection system and associated ice detection system provided by 

large airplane manufacturers should not be attributed to requirements contained 

in this final rule. As noted in the preamble for the final rule and in the response 

to comment, to demonstrate compliance, analysis may be used for the radome as 

a potential airframe ice source. Applicants may use qualitative analysis of the 

design supported by similarity to a previous design that has shown successful 

service history to have confidence that the historical methodology for 

certification. As a result of these comments guidance material has been revised 

which clarifies the use of in-service experience, similarity, and breakup of inflight ice accretions. 

In addition, the FAA eliminated the large transport category part 25 airplane 

requirements from § 25.1093. This significantly lowered the certification and 

operating costs for future newly certificated large part 25 airplanes. While large 

airplanes will not need to consider Appendix O SLD conditions for compliance 

with engine inlet or performance and handling requirements for newly 

certificated large part 25 airplanes, the final rule will add system design 

requirements for these airplanes delivered to the U.S. Therefore, the final rule 

will only add certification costs for system design requirements to large part 25 

airplane manufacturers who deliver airplanes to U.S. operators. 

Ice detection technology to distinguish between various icing conditions will 

likely be developed for airplanes required to demonstrate safe operation 

following encounters with SLD conditions in accordance with § 25.1420. 
46

Specifically, airplanes with a maximum takeoff weight less than 60,000 pounds 

or equipped with reversible flight controls. Changes to existing ice detection 

technology are not necessary for large transport category part 25 airplanes since 

§ 25.1420 does not apply. 

In response to the public comments and conversations with industry, we 

incorporate the additional estimated large transport category part 25 airplane 

certification cost the final rule adds. Initially a manufacturer indicated a total of 

$35-$49 million per large airplane certification. Technical and cost clarifications

were obtained and ranges were provided. As a result, we use point estimates 

within the ranges that were provided and have adjusted and removed the 

approximate cost related to the radome ice protection system, the ice detection 

system, and the flight and wind tunnel tests. Table 15 shows the estimated cost 

to be in compliance with these final requirements. 

TABLE 15 –FIXED CERTIFICATION COSTS PER AIRPLANE TYPE

For the NPRM, manufacturers provided the additional amount of time required 

to show compliance with the rule. Manufacturers informed the FAA that 

additional amount of time required by the rulemaking is for system architecture, 

integration, and analysis so that the pilot is given information on the speed of the 

airplane, the angle of attack and the ability to safely operated the airplane in 

icing conditions. The additional cost per certification equaled the fixed 
47

validation cost plus the additional compliance hours multiplied by the burdened 

hourly cost for engineers. Table 16 summarizes these costs. 

TABLE 16 –CERTIFICATION COSTS PER AIRPLANE TYPE NOT INCLUDED 

IN THE NPRM

For the NRPM, industry representatives provided estimated additional 

certification costs for derivative airplane programs. A certification cost for a 

derivative airplane program is expected to be less because, overall, the derivative 

process is less complex than for a new design. As such, manufacturers have 

provided a range based upon the complexity of the project. For the final rule, the 

FAA adjusted the certification cost for derivative airplanes by removing the 

approximate costs related to the radome ice protection system, the ice detection 

system, and the flight and wind tunnel tests and estimated a total cost for a large 

airplane derivative of about $1.5 million per certificate.

When the additional cost of roughly $1.6 million is added to the previously 

estimated large part 25 airplane certification cost of $4.0 million, the total cost is 

about $5.6 million per large aircraft certification. Derivative airplanes are not 

included in our estimate of new airplane certifications. To account for 

derivatives and produce a conservative estimate, we front-loaded the $1.5 

million airplane certification cost of future derivatives of new airplanes by

adding it to the $5.6 million per large airplane certification. This brings the total 

costs the final rule adds to the certification of large transport category part 25 

airplanes to about $7.1 million per certificate.
48

We then multiply the total cost of a large transport category part 25 airplane 

certification by 2 certifications we estimated in the Large Transport Category Part 

25 Airplane Fleet” section. The results of these calculations equal about $14.1 

million over the 10-year certification period.

Recurrent Hardware and Fuel Costs – Large Airplanes

A significant cost factor received during the comment period involved the 

additional hardware and recurring cost that manufacturers would incur on large 

airplanes as a result of this final rule. 

The commenter estimated the total additional costs with assumptions that the 

addition of radome ice protection and increased engine inlet ice protection, as 

well as new ice detection systems would be required to comply with the final 

rule. As discussed earlier, the commenter incorrectly assumed that design 

changes associated with a new radome ice protection system as well as changes 

to the ice detection system would be necessary to comply with this rule for large 

airplanes. Not all of these costs are attributable to this final rule because 

applicants may show compliance by using qualitative analysis of the design 

supported by similarity to a previous design with a successful service history.

We also received comments regarding fuel consumption costs for large airplanes, 

which our initial analysis did not include. Since the NPRM, the manufacturers 

have identified additional weight associated with the design changes for the 

engine inlet anti-ice protection system. In response to comments, the FAA 

revised § 25.1093(b) to remove consideration of appendix O icing conditions for 

large airplanes. This eliminated the requirement for additional hardware on 

future newly part 25 certificated large airplanes. As such, there will be no 

additional weight on large airplanes because of the elimination of the hardware, 

and therefore, no additional fuel costs. 
49

As such, for this final rule, there are no additional recurrent costs for large 

airplane operators. 

We now discuss the fixed and recurrent costs to manufacturers and operators of 

other part 25 airplanes. 

Other Part 25 Airplane Certification Costs

We use the same costs for the other part 25 airplane certifications as we did in the 

NPRM for the small and medium airplane certifications. For the NPRM, 

manufacturers provided the FAA with hourly estimates for the certification cost 

across the summary categories shown in table 17. For the final rule, we have 

combined the small and medium fleet analysis into one category, other part 25 

airplanes, for transparency and clarity. Based on their information, the estimated 

cost of this rule for each new other part 25 airplane design is shown in table 17. 

Commenters stated these costs are somewhat low but sufficiently accurate for the 

purposes of this evaluation. Multiplying this new certification cost by the 

number of other part 25 airplane certifications calculated in the “Fleet” section (2)

yields the total new cost for other part 25 airplane certifications. 

TABLE 17 – TOTAL OTHER PART 25 AIRPLANE CERTIFICATION COSTS
50

We now discuss the derivation for each of the cost categories from Table 17.

Other Part 25 Airplane System Design, Certification and Analysis Costs

As shown in table 18, manufacturers expect to incur design, certification, and 

supporting analysis costs per design. They provided detailed hourly estimates 

for design, certification, and analysis to be in compliance with this final rule. 

Table 18 shows these detailed estimates with the system design and certification 

cost breakdown of what the manufacturer might do to show compliance with the 

requirements contained in this final rule. 

TABLE 18 – OTHER PART 25 AIRPLANE SYSTEM DESIGN, CERTIFICATION 

AND ANALYSIS COSTS

Other Part 25 Airplane Aerodynamic Wind Tunnel Tests Costs

Wind and icing tunnel tests are frequently done to reduce the amount of flight 

tests in natural icing conditions because flight testing in general is costly. Wind 

and icing tunnel testing would be performed in order to demonstrate and certify 

to the requirements and confirm the analysis results. The costs per design for 

wind tunnel tests are shown in Table 19. 
51

TABLE 19 – OTHER PART 25 AIRPLANE TUNNEL TESTING

Other Part 25 Airplane Analysis Cost

There will be some variability in the various manufacturers’ methods for 

certification, and each manufacturer typically uses a variety of analysis and test 

methods to optimize the airplane and ice protection systems design. The

additional analysis cost for compliance with the requirements is shown as 

“Analysis Subtotal” in Table 17. 

Other Part 25 airplane Flight Testing Costs

Manufacturers expect to perform flight testing to show compliance with the 

requirements contained in this final rule. The primary purpose of flight testing is

to determine that the design is effective and performs its intended functions 

during flight as predicted by analysis. The flight testing is also used to evaluate 

any degradation in performance and flying qualities, to verify the adequacy of 

the flightcrew procedures and limitations, and to confirm that the power plant 

installation performs satisfactorily while in icing conditions. The costs are based 

upon the initial industry estimates for the approximate number of hours required 

to demonstrate compliance with the requirements. As in the NPRM RIA, we use 

the hourly cost of labor as an estimate when appropriate. An airplane 
52

manufacturer commented that they found the hourly costs of flight testing to be 

somewhat low, but sufficiently accurate for the purposes of his final rule 

evaluation. For hourly unit costs that differ from our standard labor rates, we 

have updated industry estimates. The details provided by the industry are 

shown below and comprise the largest estimated proportion of certification costs 

because they require several additional items that support the actual airplane

testing (such as but not limited to icing tanker rental, renting a chase airplane, 

and flying the airplane to required location). Table 20 lists the estimated cost 

elements with the total estimated cost for the flight testing accompanying each 

certification of roughly $5.3 million.

TABLE 20 - FLIGHT TESTING
53

Other Part 25 Airplane Hardware Costs

As in the initial regulatory evaluation, we continue to use the industry-provided 

SLD ice detector cost estimate of $10,000. Approximately 50% of the affected 

deliveries of other part 25 airplanes will need SLD ice detectors because we 

estimate roughly 50% of airplanes would be certified using visual cues and the 

remaining would already be certified with detectors. When the ice detector costs 

of $10,000 are multiplied by the estimated fleet per year and summed cost over 

the period of analysis, table 21 shows the total estimated hardware costs. 

TABLE 21 – OTHER PART 25 AIRPLANE HARDWARE COSTS

* Details may not add to row or column totals due to rounding.

Other Part 25 Airplane Fuel Costs

This rule will result in additional operating costs, from the hardware required by 

this final rule, and accompanying weight changes on each of the other part 25

airplanes. In this analysis, we incorporate the recent cost of fuel forecast using 

data from the FAA Aerospace Forecast from 2011. We use this forecast along 

with the fuel consumption methodology as explained in FAA’s guidance, 

Economic Values for FAA Investment and Regulatory Decisions,36 the annual flight 

 36 http://www.faa.gov/regulations_policies/policy_guidance/benefit_cost/
54

hours per airplane,37 and the annual FAA fuel cost forecast per gallon38 in order 

to estimate the additional cost of fuel per affected other part 25 airplanes.

 

Again, as in the NPRM we use the 50% factor to account for our fuel 

consumption cost estimates as only that portion of the other part 25 fleet will

incur the cost of carrying the additional SLD ice detectors. 

For the other part 25 airplanes, the additional incremental weight impact is first 

multiplied by the average fuel burn factor per airplane. This product is then 

multiplied by the flight hours and then by the cost of fuel to estimate the annual 

additional fuel consumption cost.

 

As in the NPRM, we calculate the annual additional cost of fuel by multiplying 

the estimated additional industry-provided hardware weight of approximately 

19 pounds by the fuel burn factor of 0.005 gallons per hour per pound to arrive at 

0.095 gallons per hour per airplane. This product is then multiplied by the 

annual average weighted flight hours per airplane of 2,245 hours and finally by 

the annual FAA fuel cost forecast per gallon to arrive at the annual estimated 

additional cost of fuel for each of the other part 25 airplanes.

 

The estimated annual additional fuel cost per airplane, is multiplied by the

affected other part 25 fleet. The industry expects roughly one half of the 

estimated affected fleet will not incur such costs. When multiplied by the 

affected annual fleet of airplanes that will incur cost because of this final rule, 

 37 http://www.faa.gov/data_research/aviation_data_statistics/general_aviation/CY2010/ 2010 GA Survey -

Business Turbo Jet Table 1.1 and 1.4, http://www.oagaviation.com/, OAG Aviation Solutions Fleet iNet 

Database - May 2012.

38 http://www.faa.gov/about/office_org/headquarters_offices/apl/aviation_forecasts/aerospace_forecasts/

FAA Aerospace Forecasts 2011-2031, Table 18.
55

and summed over the period of analysis, table 22 shows the total airplane fuel 

cost. 

TABLE 22 – OTHER PART 25 AIRPLANE FUEL COSTS

* Details may not add to row or column totals due to rounding.

Engine Certification Costs

The engine requirements contained in this final rule will increase costs to engine 

manufacturers. Similar to the NPRM RIA, we analyze and evaluate the part 33 

engine certification costs separately. Manufacturers provided data based upon 

revised AC 20-147, Turbojet, Turboprop, and Turbofan Engine Induction System Icing 

and Ice Ingestion, which shows acceptable compliance methods. The part 33 
56

engine manufacturers did not object to the costs estimated in the NPRM RIA. As 

such, we use the same cost estimates that were originally provided. The total 

additional costs for part 33 designs are shown in table 23. 

TABLE 23 - ENGINE COST SUMMARY

We now discuss the derivation for each of the cost categories from table 23.

The final revisions for engine certification will change the environmental 

requirements to evaluate engine protection and operation in icing conditions. 

The effect of the change will require an evaluation of safe operation in the 

revised icing environment through either test or analysis. The rules will require 

engines and engine installations to operate safely throughout the SLD conditions 

defined in new part 25, appendix O, and the newly defined mixed phase and ice 

crystal conditions in new part 33, appendix D.

Industry has provided data for several different engine “sizes,” and we 

aggregated this data to determine an average cost per engine certification. The 

data was further sub-divided into certification and capital costs. Table 24 shows 

the estimated certification costs per program. These costs are expected to occur 

once for every new certification program. 

TABLE 24 – ENGINE COSTS PER CERTIFICATION
57

From 1996-2005, there were 16 new part 33 turbine engines, or 1.6 engines per 

year. For this analysis, we conservatively assume all 16 engine certifications will 

occur at the end of the first year of analysis. With certification costs of $496,000 

per certification, the total estimated “Engine Certification Cost” is shown in 

Table 26.

 

In addition to these certification costs, there will be additional capital costs to 

modify manufacturer facilities in order to provide an ice crystal cloud (as way of 

showing compliance with the requirements). The estimated cost is $1 million per 

engine manufacturer. We expect all 6 manufacturers of part 33 engines to incur 

this cost in 2015. The total estimated “Engine Capital Cost” is shown in Table 26

 

The capital cost plus the certification cost equals the”Total Engine Costs” shown 

in Table 26.

Additional Airplane Operating Costs

In the NPRM RIA, the FAA originally asked ARAC to estimate other operational 

costs beyond the additional hardware and fuel consumption costs. Accordingly, 

ARAC provided this data to the FAA. However, as we neared completion of our

cost analysis for these requirements in the NPRM, we queried individual 

operators, and the Chief Pilots informed us they were already in compliance and 

there were no additional operational costs beyond fuel and hardware. 

When asked about the existing operations in SLD, Chief Pilots and operators 

referenced AC 91-51A, Effect of Icing on Aircraft Control and Airplane Deice and 

Anti-Ice Systems, where:
58

“...Pilots can minimize the chance of a roll upset by being sensitive to cues that 

identify severe icing conditions before control or handling characteristics of the 

airplane are degraded to a hazardous level.”

In addition to the guidance documents and crew training, operators referenced 

airplane flight manuals that require the flightcrew to exit severe icing conditions; 

which could include SLD icing conditions. Everyone in the industry that was 

queried recognizes the dangers of operating in SLD conditions and intends to 

avoid these conditions. Operators routinely, and on a regular basis, incur SLD 

operational costs from diversions by exiting SLD conditions, diverting to 

alternate airports, and cancelling flights. Operators continue to acknowledge 

these as existing costs and agree there might be only minimal incremental costs 

as a result of the certification requirements contained in this final rule. An 

airplane manufacturer disagreed and commented that there would be additional 

costs. An association indicated that one operator would incur operational costs 

but did not give specifics. We made several attempts to validate these claims but 

were not able to do so. Similar to the NPRM, we do not attribute these 

operational costs to the rule because operators are already incurring them and 

there will not be significant costs beyond what operators currently incur. 

Airplane Certification Costs - International Impact

While we estimate international compliance costs, we do not include these costs 

in the overall cost of compliance because these costs occur outside the U.S. As 

discussed in the fleet analysis, it was necessary to estimate the number of designs 

by foreign companies to determine the number airplane deliveries from foreign 

manufacturers to the United States.

 

As described earlier in the “Large Transport Category Part 25 Airplane 

Certification Costs” section, the cost per large airplane certification is about $4.0

million, plus about $1.6 million as described by industry in the NPRM 
59

comments, plus the $1.5 million cost for large airplane derivatives. We assume

one new certification over the next ten years. The total estimated international 

impact to large part 25 airplane foreign manufacturers is shown in table 25. 

As estimated earlier in the “Other Part 25 Airplane Certification Costs” section, 

each new other part 25 airplane certification will be about $9.5 million. During a 

10-year certification period, there will be roughly 3 foreign new other part 25 

airplane programs as identified by manufacturers. As such, table 25 shows the 

international cost to the other part 25 airplane foreign manufacturers.

We then add the cost of large transport category part 25 airplanes to foreign 

manufacturers to the international cost to the other part 25 airplane 

manufacturers, and table 25 shows the total estimated future cost to foreign 

manufacturers over the 10-year analysis interval.

TABLE 25 – INTERNATIONAL PART 25 AIRPLANE CERTIFICATION COSTS

Cost Summary 

Table 26 shows the estimated total costs for the period of analysis by category. 
60

TABLE 26 - COST SUMMARY

* Details may not add to row or column totals due to rounding.

The present value costs are compared to the present value benefits in Table 27 in 

the “Benefit Cost Summary” section. 

Benefit Cost Summary 

The affected fleet and categories of benefits and costs are analyzed over different 

time periods due to different production and life cycle and are customized to 

each fleet and to the requirements of this final rule. Due to the different life 

cycles it is important to focus on present value benefits and costs. Just averting 

one fatal accident with seven averted fatalities is sufficient to justify this rule. 

The accident risk is high enough that the estimated benefits for both the large 

and other transport category airplanes has increased since the publication of the 

NPRM.

Table 27 shows the breakout of the benefits and costs by large transport category 

part 25 airplanes and other part 25 airplanes; clearly the benefits exceed the costs.
61

TABLE 27 –BENEFITS AND COSTS BY AIRCRAFT TYPE

* Details may not add to row or column totals due to rounding.
62

Appendix
63

Appendix 1

U.S. Operated Retired Large Turbojet § 25 Airplanes
64

Appendix 1 (continued)
65

Appendix 2

U.S. Operated Large Turbojet § 25 Airplane Average Production Run
66

Appendix 2 (continued)
67

Appendix 3

U.S. Operated Large Turbojet § 25 Airplane Annual Number of Deliveries
68

Appendix 3 (continued)
69

Appendix 4

TABLE 4-1 – DERIVATION OF ACCIDENT AND CASUALTY RATES 

* Details may not add to row or column totals due to rounding.
70

Appendix 4 (continued)

TABLE 4-2 – DERIVATION OF BENEFITS 

* Details may not add to row or column totals due to rounding.
71

Appendix 5

U.S. Operated Retired Other § 25 Airplanes
72

Appendix 6

U.S. Operated Other § 25 Airplane Average Production Run
73

Appendix 6 (continued)
74

Appendix 7

U.S. Operated Other § 25 Airplane Annual Number of Deliveries
75

Appendix 7 (continued)
76

Appendix 8

Estimated Market Value of Air Carrier Aircraft

In August 2008, APO updated the 2003$ aircraft residual values in Table 5-1 from 

the “Economic Values for FAA Investment and Regulatory Decisions, A Guide”39 

because the FAA wanted a more current estimate of aircraft values based on 

2008 economic market conditions.

The FAA updated Table 5-1 using two proprietary industry databases. The first 

industry database was the OAG Aviation Solutions Fleet database 40 and 

reported the number of aircraft operated in the U.S. The second industry 

database was the Airliner Price Guide41 and provided aircraft values by 

equipment type. We aggregated the aircraft values into the aircraft value 

categories from Table 5-1 and calculating a weighted average for each economic 

value category using the number of aircraft operated in the U.S.

The following table shows the updated of values for passenger and cargo air 

carrier aircraft by economic value category. 

 39http://www.faa.gov/regulations_policies/policy_guidance/benefit_cost/media/ECONOMICVALUESFOR

FAAINVESTMENTANDREGULATORYDECISIONS10032007.pdf. 

40 OAG Aviation Solution, 3025 Highland Pkwy, Suite 200, Downers Grove, Il 60515, July 2008

41 Airliner Price Guide, 568 Waterloo Road, Suite 102, Warrenton, VA 20186, July 2008
77

Appendix 9

Value of Statistical Life
78

Appendix 9 (continued)