1、 AEROSPACEINFORMATIONREPORTSubmitted for recognition as an American National StandardREPORT ON AIRCRAFT ENGINE CONTAINMENTSAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. Theuse of this report is entirely v
2、oluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is thesole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your
3、writtencomments and suggestions.Copyright 1996 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.Land Sea Air and SpaceFor Advancing MobilityThe Engineering SocietyINTERNATIONAL400 Commonwealth Drive, Warrendale, PA 15096-0001Issued 1977-10Revised 1996-08REV.AIR1537 AINTRODU
4、CTION AND BACKGROUNDOn April 23, 1973 the Safety Standardization Advisory Committee of the SAE Aerospace Councilrequested the Propulsion Division to initiate a technical study of aircraft gas turbine non-containment. This request was reviewed with the Aerospace Council and the Propulsion Division wa
5、s directed toestablish an Ad Hoc Committee.The committee was established on May 5, 1975 and a preliminary work statement was drafted. Thefirst meeting of the committee was held on July 31, 1975 and the work statement was agreed to asfollows:Committee Representation: The Committee shall be composed o
6、f individuals competent andauthoritative in the fields of airline operation, airframe and engine design, and able to make significantcontributions to this study.Committee Report: The Committee is to release the results of the study to the SAE Aerospace Councilafter approval of the Aerospace Propulsi
7、on Division. The Committee shall submit its report January 31,1977 to the Propulsion Division. An extension may be granted by the Propulsion Division if required.The committee decided that commercial helicopter operations were so small, in comparison to fixedwing aircraft operations, that their incl
8、usion in this study was not warranted. General aviation was notconsidered as it was beyond the scope of this committee.Committee Membership and Activity: As stated in the Statement of Work for the committee: “Thecommittee shall be composed of individuals competent and authoritative in the fields of
9、airlineoperation, airframe and engine design, and able to make significant contributions to this study.”The individuals forming the committee were selected from companies in the fields of airline operation(Pan American, Trans-World and United), airframe design (Beech, Boeing, Lockheed and McDonnellD
10、ouglas), engine design (AiResearch, Allison, General Electric, Pratt the details are given in the text. Penalties imposed on aircraft systems to achieve greater levels ofcontainment were evaluated in terms of weight. The committee concluded that the majority of non-containment occurrences which invo
11、lved significant or severe damage to the aircraft were due torelease of fragments of such size and energy as to make the additional mass required forcontainment impractical within the current state-of-the-art. Although the probability of major aircraftaccident caused by non-contained failure is remo
12、te, this must be considered an important elementof overall aircraft system safety and the committee therefore recommends continued effort toreduce this hazard.3. CONCLUSIONS, OBSERVATIONS, AND RECOMMENDATIONS:3.1 Conclusions:3.1.1 A total of 275 non-contained engine failures occurred in 417 million
13、engine hours resulting in arate of 0.66 events per million hours. Of these, 0.54 events per million hours caused minor orno damage to the aircraft; 0.11 events per million hours caused significant damage; and 0.01events per million hours caused severe damage.3.1.2 Engine non-containment was a factor
14、 in 0.33 percent of all fatalities, 2.62 percent of allaccidents and 1.05 percent1of all hull losses which have occurred in commercial aircraft fromall causes.3.1.3 Although the probability of a major aircraft accident caused by an engine rotor burst isextremely low, it must be considered an importa
15、nt element of overall aircraft safety andcontinued effort to reduce the hazard from engine rotor burst is warranted.3.1.4 Causes of failure were classified in 15 categories. No single cause contributed more than onequarter of the total failures. High-cycle fatigue, low-cycle fatigue and material def
16、ects togetheraccounted for one half of the total disk and spacer failures.3.2 Observations:3.2.1 The greatest potential for reduction of significant damage to the aircraft caused by non-contained rotor failures lies in continued major efforts by the engine manufacturer to improveengine design, manuf
17、acturing and quality control to reduce the number of rotor bursts and bythe airframe manufacturer to minimize the hazard to the aircraft of non-contained enginefragments.3.2.2 The majority of non-containment occurrences which involved significant or severe damage tothe aircraft were due to release o
18、f fragments of such large size and energy as to makecontainment impractical within the current state-of-the-art._1Corrected from “0.05 percent” to “1.05 percent” April 1978.SAE AIR1537 Revision A- 6 -3.3 Recommendations:Recommendations are made as follows that:3.3.1 A data retrieval system be set up
19、 to collect detailed data including failure cause (primary orsecondary) for non-contained rotor events.3.3.2 Continuing, and in some areas, augmented efforts to reduce the frequency of bird ingestion atairports be carried out.3.3.3 Research be carried out to provide better understanding of aerodynam
20、ic excitation, mechanicalexcitation and interactions of blade/rotor/stator systems leading to improved design criteria fornormal and off design engine operations. This research should also include the effect on theengine and the installed engine system of potential engine and system malfunctions and
21、external influences.3.3.4 Continued research and major efforts to improve the sensitivity and reliability of NDI (NonDestructive Inspection) methods be carried out.3.3.5 Research be carried out to provide an improved capability for understanding the dynamics ofengine rotor systems subsequent to blad
22、e loss, to permit establishing effective design criteriaand practice to minimize the effects of blade loss and to reduce the sometimes extensivesecondary damage that results.3.3.6 Continuing research and development on damage tolerant blade designs be carried out.3.3.7 Engine burst characteristics b
23、e better defined in terms of fragment sizes and energies,fragment population and dispersion angles.4. DEFINITIONS:4.1 Definition of Non-Containment:Non-containment failure of an aircraft turbine engine was defined for the purposes of this studyas any failure which results in the escape of rotor frag
24、ments through the nacelle cowling orthrough panels which isolate the propulsion installation from the remainder of the aircraftstructure. The term rotor includes rotating structural components such as disks, spacers, andblades. Rotor failures of primary importance in this study are those which relea
25、se fragments ofsufficient energy to constitute a potential hazard to the aircraft through damage to other systemsor structure outside the affected propulsion system. It should be noted that aircraft certified underF.A.R. Part 25 are capable of continued safe operation after loss of power/thrust from
26、 one engineduring any phase of flight.SAE AIR1537 Revision A- 7 -4.1 (Continued):Fragments of disks, spacers, and/or blades which are released from turbine engines canrepresent a hazard because of the potential for injury or damage to aircraft structures or systems.There is, however, a clear distinc
27、tion in the risk of aircraft accident associated with cases wherefragments are contained within the propulsion system/nacelle and the instances where fragmentshave enough energy to penetrate the propulsion system cowling or skins. This distinction isdrawn because the fragments contained within the p
28、ropulsion system do not represent a hazardto personnel, airframe structures or systems. The propulsion system is designed to confine thefire or damage which might result from such a failure.4.2 Definition of Aircraft Damage:The committee agreed that a hazard from a noncontained engine failure result
29、s when damageoccurs to critical aircraft structure or systems, other than the affected nacelle. To assess theresulting aircraft damage and to determine the areas of greatest concern, a means of classifyingthe severity of the damage was developed. The severity of aircraft damage, as judged from arela
30、tive standpoint, is based upon the consequence and the damage that actually occurred. Damage severity was classified into four categories and is defined as follows:Category 1. Damage limited to the affected nacelle.Category 2. Minor aircraft damage, defined as damage that has little effect on aircra
31、ftperformance, such as:a. Nicks, dents and small penetrations in aircraft structureb. Slow depressurizationc. Controlled firesCategory 3. Significant aircraft damage, as listed below, with the aircraft continuing flight andmaking a safe landing.a. Damage to primary structure or systemsb. Uncontrolle
32、d firec. Rapid depressurizationd. Loss of thrust on an additional enginee. Minor injuriesCategory 4. Severe aircraft damage, as listed below:a. Crash landingb. Loss of the aircraftc. Critical injuriesd. FatalitiesSAE AIR1537 Revision A- 8 -4.2 (Continued):It is apparent from these definitions that C
33、ategories 1 and 2 present no hazard to the welfare andsafety of the commercial airline passenger. Thus, in analyzing the service data, Categories 3 and4 were emphasized in order to determine the areas of greatest concern.5. ANALYSIS OF DATA:5.1 Data Base:The statement of work defined the committees
34、basic task as, “to gather and analyze availableservice data on aircraft propulsion turbine engine rotating part noncontained failures on publicrecord.” Service data was obtained from NTSB, FAA and United Kingdom CAA reports for thetime period of January 1, 1962 through December 31, 1975. In addition
35、, to provide more details,certain manufacturers data were used to supplement the information provided in the governmentreports.The committee considered those events where fragments exited the nacelle, because of thepotential damage to the aircraft. Thus, the data were limited to events that met the
36、committeesdefinition of non-containment as presented in 4.1. The data include non-contained rotor failureswhich occurred during 417 million engine hours of commercial airline service for aircraft poweredby Allison, General Electric, Pratt a discernible trend is not apparent. No Category 4events occu
37、rred in the period covered, and no particular significance is attributed to year 1968when a low rate occurred. There was inadequate information to establish a rate for 1975.FIGURE 1C - NON-CONTAINED LOW BYPASS TURBOFAN FAILURES - DISKS, SPACERS,AND BLADES:Figure 1C presents data for low bypass turbo
38、fans. One Category 4 event occurred in each of twoof the fourteen years covered. It should be noted that low bypass turbofan engines account for59% of the total engine hours included in the committees investigation.FIGURE 1D - NON-CONTAINED HIGH BYPASS TURBOFAN FAILURES - DISKS, SPACERS,AND BLADES:F
39、igure 1D presents data for the high bypass engines introduced since 1970 and is the only one ofFigures 1A through 1D which shows the introduction into service of an engine type over the timeperiod covered. An initial high rate seen in the first year is the result of one event and a smallnumber of en
40、gine hours. The number of engine hours per year for this engine class has grownfrom .58 to 5.73 million hours per year in the period shown, and the data sample available coverstoo short a period for any meaningful comment with respect to trends. One Category 4 eventoccurred in each of two of the six
41、 years covered.SAE AIR1537 Revision A- 20 -6.2 (Continued):FIGURE 2 - NON-CONTAINED ROTOR FAILURE EVENTS:Figure 2 shows the total number of events and the number of events attributed to disks andspacers only classified by severity category. In Categories 1 and 2, which represent virtually nohazard t
42、o the aircraft, the disks and spacers represent approximately one half of the total events.In Categories 3 and 4 it can be seen that the major portion of these events are the results of diskand spacer failure.FIGURE 3 - EFFECT OF INCREASED CONTAINMENT - SEVERITY CATEGORIES 3 AND 4:This chart shows t
43、hat the increased containment for three blades and two posts was judged to beincapable of containing the fragments of any of the five Category 4 events. The increasedcontainment was judged to be capable of containing the fragments of only one of the 43 Category3 events and possibly capable of contai
44、ning the fragments of eight additional Category 3 events. The basis for this evaluation is given in 5.3.FIGURE 4 - INVOLVEMENT OF NON-CONTAINED ROTOR FAILURES IN TOTALACCIDENTS, HULL LOSSES AND FATALITIES:Figure 4 shows the total number and percentage of fatalities, accidents, and hull losses for th
45、etime period of this study where there was engine rotor non-containment involved in the event. Out of 11,690 fatalities due to all causes, 39 fatalities occurred where non-containment wasinvolved. It should be noted that non-containment was not judged to be the cause of the accidentby the responsibl
46、e investigating agency in all of the cases where it was involved. However, thesecases are included because non-containment was reported to be a factor.SAE AIR1537 Revision A- 21 -FIGURE 1 - Non-Contained Failures - Disks, Spacers, and BladesFIGURE 1A - Non-Contained Turboprop Failures - Disks, Space
47、rs, and BladesSAE AIR1537 Revision A- 22 -FIGURE 1B - Non-Contained Turbojet Failures - Disks, Spacers, and BladesFIGURE 1C - Non-Contained Low-Bypass Turbofan Failures - Disks, Spacers, and BladesSAE AIR1537 Revision A- 23 -FIGURE 1D - Non-Contained High-Bypass Turbofan Failures - Disks, Spacers, a
48、nd BladesSAE AIR1537 Revision A- 24 -FIGURE 2 - Non-Contained Failures by Severity CategoryFIGURE 3 - Effect of Increased Containment Capability for Severity of Categories 3 and 4SAE AIR1537 Revision A- 25 -FIGURE 4 - Total Aircraft Accidents, Hull Losses and FatalitiesWhere Engine Non-Containment w
49、as InvolvedSAE AIR1537 Revision A- 26 -7. POTENTIAL FOR IMPROVEMENT:As shown in Figure 4, the probability of an aircraft accident caused by an engine rotor burst is low. This is, however, an important element of overall aircraft safety and continued major effort tofurther reduce the frequency and hazard of rotor failure is warranted. In addition to safetyconsiderations, the industry has substantial economic incentives to avoid the costs associated withrotor failure.7.1 Engine Design:While an improvement may be achieved, the probability of rotor failure ca
