1、AEROSPACE RECOMMENDED PRACTICEARP1107REV.BIssued 1971-07Reaffirmed 2006-08Revised 2001-10Superseding ARP1107ATail Bumpers for Piloted AircraftFOREWORDChanges in this Revision are format/editorial only.1. SCOPE:This recommended practice covers the fixed structure, or independent energy absorbing syst
2、em affixed to the airframe to afford protection to the control surfaces, engine and other portions during ground handling, take-off and landing.2. PURPOSE:This document provides recommended practices for the design, installation, qualification, and operational requirements of the tail bumper for pil
3、oted aircraft.3. DESIGN REQUIREMENTS:3.1 Functional:The tail bumper general arrangement and design should be such as to provide a minimum clearance of 6 inches between the ground and all parts of the aircraft, including externally mounted stores, exclusive of the tail bumper itself and the landing g
4、ear wheels. This clearance should be provided for all pitch attitudes and loading conditions defined in Section 4 with the aircraft rolled laterally five degrees about the fuselage centerline. Structural deflections under the specified dynamic loading conditions should be calculated or conservativel
5、y estimated. Flight control surfaces should be in the most critical positions obtainable under the conditions being investigated.During the takeoff the tail bumper should not restrict the aircraft attitude more than necessary, consistent with the clearance requirements defined above, when maximum el
6、evator deflection is applied prior to and during takeoff rotation.SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any
7、 particular use, including any patent infringement arising therefrom, is the sole 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 written comments and suggestions. Copyright 2006 SAE
8、International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-
9、606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org RATIONALE This document has been reaffirmed to comply with the SAE 5-year Review policy. Copyright SAE International Provided by IHS under license with
10、SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP1107 Revision B- 2 -3.1 (Continued):The tail bumper may be either fixed or retractable. If takeoff rotation would otherwise be unduly restricted, different positions of the tail bumper should be provided for
11、 landing and takeoff.Selection of the means for energy absorption should be based on expected usage with emphasis on serviceability, maintainability, reliability and safety considerations.3.2 Tail Bumper Actuation:A retractable bumper may be positioned by a suitable actuator. Actuator design require
12、ments should be subject to the approval of the procuring activity and should consider the effect of rapid compression of the tail bumper during ground contact.3.3 Tail Bumper Control:When a retractable tail bumper is used in conjunction with retractable landing gear, the bumper control should be int
13、egral with the landing gear control when practicable. A suitable indicator should be provided where the tail bumper is needed to make a safe landing, or if the extended tail bumper has an unsafe effect. Tail bumpers which contact during landing impact (including occasional contact) should have emerg
14、ency extension provisions and operate with emergency landing gear control. Where bumper operation other than with landing gear control is dictated (such as bumper retraction during carrier aircraft catapult), control should be integrated with prime control for that condition (such as launch bar exte
15、nsion).3.4 Mode of Failure:The tail bumper geometry or energy absorbing device should be such that in the event of an overload, links or struts will not pierce fuel tanks or critical aircraft components.3.5 Wear Surfaces:The tail bumper should have an easily replaceable hardened shoe or tire and whe
16、el assembly to absorb the wear and damage of impact. Selection of wheel or shoe for a particular design should be based on such factors as expected frequency of contact, contact velocity, surface roughness, and damage to arresting cables or landing surface.3.6 General Design and Quality:The tail bum
17、per system should be as simple, direct, and fool-proof as possible with respect to design, operation, inspection and maintenance. Materials and finishes should be of aircraft quality, and workmanship should be of sufficiently high quality to ensure satisfactory operation and adequate service life.Co
18、pyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP1107 Revision B- 3 -4. TAIL BUMPER LOADS:The tail bumper should be designed to accommodate the following load conditions:4.1 Ground Handling Loads
19、:The airplane should be rolling backwards on a level surface (down a five degree slope for carrier based aircraft) at a speed of five knots, and brakes should be suddenly applied. The airplane gross weight and center of gravity should be the most critical for the conditions. The tail bumper loads sh
20、ould be those resulting from a dynamic analysis of the aircrafts motion considering a tire coefficient of friction of 0.95.4.2 Landing and Takeoff Loads:4.2.1 Landing Loads (Carrier Based Aircraft, Fixed Wing): Tail bumper requirements for carrier landings and field carrier landing practice (FCLP) s
21、hould be established by dynamic analysis of the airplane motion using the structural landing criteria established in Reference (a). These criteria require investigation of initial landing conditions using a multivariate probability distribution of eight independent variables.For tail bumper loads th
22、e important parameters to be investigated are pitch attitude and sinking speed. Therefore, the landing criteria can be simplified to the following:(The probability of occurrence (Po) is 0.001; therefore, PT= Po 0.5 = 0.0005)where:Vv= Airplane sink speedVvi= Sink speed initial condition value= Mean s
23、ink speed valueVvmax= Maximum sink speed valuep= Airplane pitch attitudepi= Pitch attitude initial condition value= Mean pitch attitude valuepmax= Maximum pitch attitude valueIf this joint probability is plotted, the critical tail bumper conditions occur in that quadrant where . This is depicted in
24、Figure 1.For each airplane design there is potentially a region of tail bumper contact within the design envelope (see Figure 1). This region and the corresponding bumper loads must be determined by dynamic analysis.PTPVvVvi()P ppi() 0.0005, or = PVvPp 0.0005=Vvpppipmaxand VvVviVvmaxCopyright SAE In
25、ternational Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP1107 Revision B- 4 -4.2.1 (Continued):The equations defining sink speed, pitch attitude, and accompanying parameters to be used in the analysis are contained in
26、 Reference (a) or are defined by the procuring activity.Consideration should also be given, as specified by the procuring activity, to the loads resulting from tail bumper contact with an arresting cable at any time during the landing.4.2.2 Landing Loads (Land-Based, Fixed Wing Aircraft): Tail bumpe
27、r landing loads should be established by dynamic analysis of the motion of the aircraft. The analysis should be based on initial contact under the following conditions:Sink Speed = Design limit sink speed, as specified by the procuring activity, relative to the ground.Gross Weight = Landing Design G
28、ross WeightCenter of Gravity = Most aft permissibleCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP1107 Revision B- 5 -4.2.2 (Continued):True Airspeed = 1.1 for the specified gross weight and
29、center of gravity. is the minimum speed for level flight at sea level in the landing configuration with Intermediate Power.Flight Path = The glideslope that results from the specified sink speed and true airspeed in still air.Pitch Attitude = The nominal attitude that will result in steady state fli
30、ght along the flight path at the specified airspeed when in ground effect, plus a nose-up deviation of “C“ degrees. The value of “C“ should be determined statistically and specified by the procuring activity. In the absence of a specified value, a value of 3 deg should be used.4.2.3 Landing Loads (H
31、elicopter): Tail bumper landing loads should be based upon a dynamic analysis of the aircrafts motion for the sink speeds, attitudes and weights described below.Tail down attitude is defined as main wheels in contact with the ground (wheels unloaded) with the airplane at angle of pitch for maximum l
32、ift or at maximum angle permitting ground clearance of all parts of the airplane, except if fitted with tail bumper, the tail bumper should be completely compressed, whichever is the lesser angle.Autorotative flare attitude is defined as the maximum resultant angle of attack with which the aircraft
33、can safely descend in autorotation.4.2.4 Takeoff (Fixed Wing Aircraft): Tail bumper takeoff loads should be based on a dynamic analysis of the airplanes motion for the full range of takeoff gross weights, C. G. positions, and velocities. The bumper should be capable of absorbing the aircrafts rotati
34、onal energy produced by full elevator deflection for speeds up to 1.1 VSPA.Weight Attitude Sink Speed (Ft/Sec)Basic Structural Design Tail Down 10Gross WeightAutorotative Flare (15)12.25VSPAIntermediate Power()VSPAIntermediate PowerCopyright SAE International Provided by IHS under license with SAENo
35、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP1107 Revision B- 6 -4.2.5 Associated Loads: The tail bumper and aircraft structure should be designed for limit side loads equal to 20% of the simultaneous vertical load (50% for helicopters), and for limit aft d
36、rag load equal to 50% of the simultaneous vertical load. Side, drag, and vertical loads should be considered to act simultaneously with the bumper in all positions from fully extended to fully compressed. A forward acting (negative) drag load equal to 50% of the simultaneous vertical load should be
37、used in combination with the vertical loads determined per paragraph 4.1.5. TESTS:A test plan, based on loads derived as described above, should be developed to prove the structural integrity of the tail bumper and bumper attach structure and to demonstrate the functional consistency of the system.
38、This plan should be submitted to the procuring activity for approval6. QUALIFICATION OF COMPONENTS AND SYSTEMS:6.1 Components:Each component should be qualified in accordance with the applicable design document for each type of unit. Shock absorber units should be qualified by appropriate dynamic te
39、sts to demonstrate energy absorption capability. All structural components should be subjected to ultimate static load tests.6.2 System:The system should demonstrate within 10% the ability to perform within the specified design performance requirements. The system should demonstrate the ability to m
40、aintain 6 inches structural clearance through loading conditions.7. DATA REQUIREMENTS:Data to be submitted to the procuring activity should include at least the following:a. Complete drawingsb. Energy absorption analysisc. Fault analysis8. REFERENCES:a. MIL-A-8863A, “Airplane Strength and Rigidity G
41、round Loads For Navy Procured Airplanes,“ 12 July 1974.PREPARED UNDER THE JURISDICTION OFSUBCOMMITTEE A-5B, GEARS, STRUTS, AND COUPLINGS OFSAE COMMITTEE A-5, AEROSPACE LANDING GEAR SYSTEMSCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
