U.S. Department of Transportation 

FEDERAL AVIATION ADMINISTRATION 

Office of Aviation Policy and Plans 

Washington, D.C. 20591 

FINAL REGULATORY EVALUATION 

FINAL RULE 

FLIGHTCREW ALERTING 

14 CFR PART 25.1322 

OFFICE OF AVIATION POLICY AND PLANS 

REGULATORY ANALYSIS DIVISION 

George A. Euring, Jr. 

May 4, 2010 
Table of Contents

I. Introduction......................................................................1 

II. Changes From The Initial Regulatory Evaluation...........................2 

III. Overview of Assumptions and Analysis Period.............................3 

IV. Benefits...........................................................................4 

V. Costs...............................................................................8 

VI. Comparison of Benefits and Costs.............................................9 

 Endnotes...........................................................................10 

i 
I. Introduction

This Final Rule amends the flightcrew alerting airworthiness standards for newly 

certificated transport category airplanes. The purpose of alerting functions on airplanes is 

to gain the attention of the flightcrew, inform them of specific airplane system conditions 

and certain operational events that require their awareness, and make them aware of 

actions to address the condition. 

The current design requirements do not adequately address the flightdeck display 

technology in use today. The requirements in this final rule will enable certification of 

recent technological advances in the flightdeck. These new design requirements will 

address requirements for definitions, prioritization, color requirements, and performance 

for flightcrew alerting. 

The requirements contained in this Final Rule are based upon Aviation 

Rulemaking Advisory Committee (ARAC) recommendations. The changes to § 25.1322 

will expand and update the current § 25.1322 from addressing only visual alerting lights 

to including all flightcrew alerting functions. These flightcrew alerting functions include 

not only visual alerting lights but also aural, tactile, other visual display alerting methods, 

and integrated smart flightcrew alerting systems. The title of existing § 25.1322 will 

change from “Warning, caution, and advisory lights” to “Flightcrew alerting.” This new 

title encompasses all of the changes included in the final rule. 

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II. Changes From The Initial Regulatory Evaluation

The final rule was changed as a result of comments received on the proposed rule. 

However, the changes were not significant in terms of the Regulatory Evaluation. 

Therefore, the conclusions of the Initial Regulatory Evaluation were not changed as a 

result of comments received on the proposed rule. 

Comments were received on the Regulatory Flexibility Analysis and the 

Unfunded Mandates Assessment. The comments regarding the Regulatory Flexibility 

Analysis are addressed in the Final Regulatory Analysis. The Unfunded Mandates Act 

requires a written statement of any Federal mandate where such a mandate exceeds $100 

million or more in 1995 dollars. The FAA estimates the cost of this final rule to be less 

than $10 million and thus, the requirements of the Unfunded Mandates Act do not apply. 

No comments were received on the Initial Regulatory Evaluation. Therefore no 

changes were made to the Initial Regulatory Evaluation as a result of comments received. 

2 
III. Overview of Assumptions And Analysis Period

The FAA assumed that the requirements contained in the NPRM and this Final 

Rule would become effective in 2010. The requirements apply only to new type 

certificates, new amended type certificates, and new STCs for transport category 

airplanes. 

The analysis period for this final regulatory evaluation begins in 2010 and ends 

twenty years later in 2029. It is likely that new airplane designs will occur over time and 

we used a uniform distribution to estimate both costs and benefits during the analysis 

period. 

The FAA used twenty years of historical type certificate information to estimate 

the design costs for future new airplane certifications. For the benefits, the FAA 

examined the history of flightcrew alerting events. 

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IV. Benefits

The final requirements will increase flight safety by setting standards for alerting 

elements in future flightdecks, including cueing by more than one sense, information 

content, ease and immediacy of detection, and alert intelligibility. 

Industry representatives provided the FAA with examples of events that support 

the need for revising the current design standard. The representatives informed us that 

the final requirements (if implemented during the aircraft design) could have eliminated 

or mitigated these events. We have summarized below some of the events provided by 

industry. These accidents deal primarily with ineffective crew alerting. 

1. On February 19th, 1985, a Boeing 727 took off from Madrid-Barajas 

Airport and was scheduled to land at Bilbao Airport. There was a fatal accident that 

resulted in 141 passenger and 7 crewmember deaths. 

The investigations revealed that the cause of the accident was the altitude 

alert system and the misinterpretation of its warnings. [1] The requirements in this 

rule will clarify the warnings, thereby decreasing the probability of this type of 

accident occurring. 

2. On August 16, 1987, a DC 9-82 (flight 255) crashed shortly after taking 

off from Detroit Metropolitan Wayne County Airport, Romulus, Michigan. The 

aircraft was a regularly scheduled passenger flight en route to Phoenix, Arizona, 

with 149 passengers and 6 crew members. On board, 148 passengers and 6 crew 

members were killed; 1 passenger, a 4-year-old child, was injured seriously. On the 

ground, 2 persons were killed, 1 person was injured seriously, and 4 persons 

suffered minor injuries. 

The National Transportation Safety Board (NTSB) determined that one 

contributing factor was the airplane takeoff warning system, which failed to warn 

the flightcrew that the airplane was improperly configured for takeoff. This failure 

was due to the absence of electrical power. 

Specifically, the NTSB determined that the disabled warning system was a 

factor in the accident. Analysis led to a pulled, but not failed circuit breaker. The 

NTSB considered the possibility that the circuit breaker was used as a switch and 

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intentionally opened to disable the warning system. This might occur if the 

flightcrew were annoyed or distracted by nuisance alerts. 

During the public hearing, nearly every pilot witness testified that 

periodically throughout their careers, they had regained the use of a system or 

component by opening and resetting the applicable circuit breaker. 

The requirements contained in this Final Rule will require manufacturers to 

have a reliable alerting system and minimize nuisance alerts. These design 

requirements will also allow the crew to suppress an undue warning without 

deactivating the whole system. 

3. This rule will also mitigate the type of accident that occurred on February 

5, 1987, when a Learjet 55 crashed in Cameroon. 

An intermittent anemometric failure occurred in cruise and caused an undue 

overspeed warning. To silence this false but very intrusive warning, the crew 

reduced speed to maneuver the aircraft out of overspeed. When the aircraft slowed 

to the point of triggering a valid stall warning—a much less intrusive aural alert 

called a nudger—the crew failed to recognize or react to it. The airplane then stalled 

and crashed. 

The accident report showed that the crew was primarily focused on stopping 

an extremely intrusive warning alarm, which hampered their ability to correctly 

analyze the situation. Typically, overspeed is not considered a catastrophic failure 

condition, especially in cruise. 

4. On November 23, 1997, a serious incident occurred involving an MD83. 

[2] The pilot was not aware of the airplane’s very low altitude when he performed 

the go-around. During the descent, the pilot lost vertical positional awareness and 

did not hear the ground proximity warning system (GPWS), altitude and autopilot 

disconnect alarms. There were multiple warnings that occurred simultaneously 

during the descent and caused confusion in the cockpit. 

5. On August 14, 2005, the crew members of a Cypriot airliner near Athens 

became confused by a series of alarms as the plane ascended. At 10,000 feet, the 

cabin pressure warning went off as designed to indicate that the plane would not 

pressurize. However, officials said that the crew members had mistaken the alert to 

be a takeoff warning, which is triggered when the controls were improperly set for 

takeoff. Both conditions use the same alert. [3] This misinterpretation resulted in 

121 deaths. [4] 

Industry representatives familiar with the aforementioned events have indicated 

that these events could have been prevented if the requirements in this final rule had been 

effective during the design and certification of the accident airplanes. [5] 

5 
Although most events were catastrophic, there were also non-catastrophic events 

that could have been prevented with the requirements contained in this final rule. One 

such event occurred on September 20, 1999. 

A part 25 airplane operating in part 121 service executed an unnecessary escape 

maneuver after the GPWS inaccurately activated. The airplane was not damaged; 

however, 2 flight attendants received serious injuries and 2 others received minor 

injuries. The NTSB indicated that this airplane’s GPWS system had a long 

standing history of intermittent faults, nuisance warnings, and erratic behavior. 

Had the final requirements (specifically minimizing nuisance alerts) been in effect 

during initial certification and aircraft development, this event could have been averted. 

Although only four people were injured in this event, many more individuals could have 

been seriously injured or killed, depending on the phase of flight and other 

circumstances. 

By examining the historical data, we have demonstrated that both fatal and nonfatal events have occurred which could have been prevented by the requirements 

contained in this Final Rule. The potential severity of an event is demonstrated by the 

August 16, 1987 accident that resulted in 154 deaths. 

To quantify the benefits of this final rule, we performed a "threshold" analysis. 

Threshold or "break-even" analysis answers the question, "How small could the value of 

the benefits be before the rule would yield zero net benefits?" [6] 

Our threshold analysis demonstrates that these final requirements need only 

prevent a total of 10 serious injuries (valued at $830,000 per injury) over the analysis 

6 
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period. The total corresponding benefits would be at least $8.3 million ($4.4 million 

present value). Given the accident history presented above, the FAA has determined that 

at least 10 serious injuries are likely to be prevented by this rule. 
V. Costs

To estimate the certification costs, the FAA examined the number of new part 25 

airplane designs for the 20-year period 1987-2006. During this time frame, 11 new type 

certificates were issued to part 25 manufacturers. The FAA used this historical data to 

estimate the average annual number of new part 25 airplane designs. The eleven new 

designs over a 20 year period equated to 0.55 new airplane designs annually. [7] 

The FAA obtained compliance cost estimates from three part 25 airplane 

manufacturers and two designers of alerting systems. The two alerting system designers 

stated that there would be no additional cost. Although the manufacturers stated there 

were no additional manufacturing or operating costs that would occur as a result of this 

proposal, they indicated there would be additional design and certification costs. 

The FAA averaged the three estimates from the part 25 airplane manufacturers and 

arrived at an average cost estimate of $0.7 million per new aircraft. When the average 

cost per new aircraft certification ($0.7 million) is multiplied by the estimated annual 

number of new certifications (0.55), the FAA arrived at annual costs of $385,000. When 

summed over the analysis period the total estimated costs were $7.7 million ($4.1 million 

present value). 

In the event of future STCs, the FAA estimates that the STC cost would be less than 

$700,000 per airplane. Anyone who would purchase the STC would value the STC at 

$700,000 or more or there would be no transaction. 

8 
VI. Comparison of Benefits and Costs

 The FAA believes that these final requirements will prevent at least 10 serious 

injuries over the analysis period, resulting in estimated benefits of $8.3 million ($4.4 

million present value). The total estimated costs are $7.7 million ($4.1 million present 

value). Accordingly, the estimated benefits of the final rule justify the costs of the final 

rule. 

9 
ENDNOTES

1. Technical Report A-009/1985 

2. http://www.bea-fr.org/docspa/1997/f-mc971123a.pdf 

3. International Herald Tribune, September 7, 2005. 

4. http://aviation-safety.net/database/record.php?id=20050814-0 

5. In addition to these events that were provided by industry representatives, there 

were other accidents and incidents where the warning systems seemed to be 

working properly but the crew for some reason did not pay attention to the 

warning. It is possible that the alerts did not have the attention getting properties 

that would be required by the requirements contained in this final rule. There 

were other situations where alerts were triggered properly, but the crews did not 

understand the alerts. In these cases, the crews might have dismissed them as 

nuisance alerts. 

6. OMB Circular A-4, September, 2003 

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7. Annual Part 25Certifications 

Year Model 

1993 A340

1995 B777

1996 EMB 134-145

1996 Cessna750

1997 Lear 45

1998 A330

2003 A318-321

2004 Embraer 170

2004 Cessna 680

2006 ERJ-190

2006 A380

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