1、Designation: F2355 10 F2355 12Standard Specification forDesign and Performance Requirements for Lighter-Than-AirLight Sport Aircraft1This standard is issued under the fixed designation F2355; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers design and performance requirements that apply for the manufacture of l
3、ighter-than-air light sportaircraft.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatoryrequir
4、ements prior to use.2. Referenced Documents2.1 ASTM Standards:2F2353 Specification for Manufacturer Quality Assurance Program for Lighter-Than-Air Light Sport AircraftF2354 Specification for Continued Airworthiness System for Lighter-Than-Air Light Sport AircraftF2356 Specification for Production Ac
5、ceptance Testing System for Lighter-Than-Air Light Sport AircraftF2427 Specification for Required Product Information to be Provided with Lighter-Than-Air Light Sport Aircraft3. Terminology3.1 Definitions:3.1.1 airshipengine-driven lighter-than-air aircraft that can be steered.3.1.1.1 DiscussionThis
6、 definition can include “and that sustains flight through the use of either gas buoyancy or an airborne heater, or both.”3.1.2 balloonlighter-than-air aircraft that is not engine-driven, and that sustains flight through the use of either gas buoyancyor an airborne heater, or both.3.1.3 design useful
7、 loadload (other than structure, engine, enclosure, and systems) that a lighter-than-air aircraft can carrywhile achieving the design defining performance requirements.3.1.4 gross weighttotaltotal aircraft system weight(s) at takeoff. The weight limits must be established so that it is: (1) thedesig
8、ned maximum weight at which compliance with each applicable structural loading condition is demonstrated, or (2) thehighest weight at which compliance at each applicable flight requirement is demonstrated.3.1.5 lighter-than-air aircraftaircraft that can rise and remain suspended by using contained g
9、as weighing less than the air thatis displaced by the gas.3.1.5.1 DiscussionAirships may include dynamic lift that derive as much as 30 % lift from other than buoyancy.1 This specification is under the jurisdiction of ASTM Committee F37 on Light Sport Aircraft and is the direct responsibility of Sub
10、committee F37.60 on Lighter than Air.Current edition approved Feb. 1, 2010Nov. 15, 2012. Published March 2010December 2012. Originally approved in 2005. Last previous edition approved in 20082010as F2355 05a (2008).F2355 10. DOI: 10.1520/F2355-10.10.1520/F2355-12.2 For referenced ASTM standards, vis
11、it the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM stan
12、dard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by AST
13、M is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.6 maximum takeoff weightgross weight limit as defined by the manufacturer, proven through compliance with thisspecification and placarded
14、on the aircraft as the not-to-exceed gross weight.3.1.7 thermal airshipcraft with airship using heated air for a portion of its lift, incorporating design features to prevent nosecollapse due to forward motion for which buoyancy is created or enhanced by heating of the gas in an otherwise unpressuri
15、zedenvelope.dynamic pressure and exempt from specific pressurized envelope requirements.3.1.8 vectored thrust ballooncraft that can move laterally, but is limited to lateral speed by its lack of thermal balloon withthrust capability that does not have design features to prevent forward envelope coll
16、apse due to forward motion.dynamic pressureand is therefore limited in its lateral speed capability.3.1.9 weight limitationsoperational weight restrictions (maximum/minimum) as defined by the manufacturer and proventhrough compliance with this specification to demonstrate controllability.4. Flight R
17、equirements4.1 Performance Requirements for Airships and Thermal Airships, except as noted:4.1.1 Proof of ComplianceEach of the following requirements shall be met at the maximum takeoff weight and most criticalcenter of gravity (CG) position. To the extent that CG adjustment devices may be adjusted
18、 for flight, these components will beevaluated in the least favorable recommended position as it affects either performance or structural strength.4.1.2 General PerformanceAll performance requirements apply in and shall be corrected to International Civil AviationOrganization (ICAO) defined standard
19、 atmosphere in still air conditions at sea level. Speeds shall be given in indicated (IAS) andcalibrated (CAS) airspeeds in knots.4.1.3 Flight PerformanceFor all flight operations it shall be shown that control sufficient to safely maneuver or land theairship, or both, can be maintained.4.1.4 ClimbT
20、he following shall be measured:4.1.4.1 Distance to clear a 15-m (50-ft) obstacle not to exceed 213 m (700 ft) from point of lift-off. Compliance with therequirements of this section must be shown at each extreme of altitude and ambient temperature for which approval is sought.4.1.4.2 Climb rates of
21、1.5 m/s (300 fpm) and 0.5 m/s (100 fpm) with one engine inoperable for multi-engine configurations.4.1.5 Controllability and ManeuverabilityThe aircraft shall be safely controllable and maneuverable during takeoff, climb,level flight (cruise), approach, and landing.4.1.5.1 Demonstrate a smooth trans
22、ition between all flight conditions shall be possible without excessive pilot skills norexceeding pilot forces of 59.1 kg (130 lb) for the foot-operated control, 9.1 kg (20 lb) prolonged application, or 29.5-kg (65-lb)hand controls, 4.5 kg (10 lb) prolonged operation.4.1.6 DescentThe following shall
23、 be measured.4.1.6.1 It must be shown that in the event of the most critical uncontrolled descent from either: (1) an engine or propellerfailure, (2) burner failure for thermal airship, (3) valve leak for either hot air or captive gas airship, or (4) the maximum permittedenvelope failure as specifie
24、d in 5.1.2.NOTE 1Procedures must be established for landing at the maximum vertical velocity attained and procedures must be established for arresting themaximum descent rate within the manufacturers specified altitude.4.1.7 LandingIt must be shown that a pilot of normal skill can achieve landing si
25、nk rates of no more than 0.77 m/s (2 ft/s).4.1.8 Stability and Control:4.1.8.1 Vertical Stability and ControlStability and control of the airship shall be determined at maximum gross weight, withminimum in-flight turbulence/wind for:(1) Maximum duration of envelope valve operation (if equipped), dur
26、ing which the airship must not enter into a dangerousdescent.(2) Minimum burner fuel pressures (if equipped), which will arrest the maximum descent rate as determined in 4.1.6 and climbas determined in 4.1.4.4.1.8.2 Longitudinal StabilityLongitudinal stability of the aircraft will be demonstrated by
27、 performing 2 min of flight withoutcontrol input for three conditions. In each case, the aircraft must not enter into dangerous or unusual altitudes. A test must beconducted at maximum gross weight, with a minimum of in-flight turbulence. The three conditions are ascent, descent, and levelflight.4.1
28、.8.3 Longitudinal ControlWith all engines operating at maximum power, the airship must be capable of:(1) A nose-down pitch from a stabilized climb with a 30 nose-up deck angle,(2) A nose-up pitch from a stabilized descent with a 30 nose-down deck angle, and(3) Longitudinal upset response shall be ev
29、aluated by analysis or test, or both, to show that it does not result in unsafeconditions.4.1.8.4 Lateral and Directional Stability:(1) Lateral stability will be demonstrated by maintaining the surface controls in a fixed position, which will initially give anunaccelerated level flight condition. Th
30、e aircraft must not enter into a dangerous altitude during the 2 min that the flight controlsurfaces are fixed. A test must be conducted at maximum operating weight, with minimum in-flight turbulence.F2355 122(2) Directional stability will be demonstrated by a separate and full deflection of each di
31、rectional flight control surfaces forthree full turns of 360 without the aircraft entering any dangerous flight altitude during the maneuver. A test must be conductedat minimum flight weight, with minimum in-flight turbulence. The demonstrated turn rate shall not be less than 6/s (60 s for a360 turn
32、) in either direction.4.2 Performance Requirements for Balloons:4.2.1 Proof of ComplianceEach of the following requirements shall be met at the maximum takeoff weight.4.2.2 General PerformanceAll performance requirements apply and shall be corrected to International Civil AviationAssociation Organiz
33、ation (ICAO) defined standard atmosphere in still air conditions at sea level.4.2.3 Flight PerformanceFor level flight, climbs, descents, and landing, it shall be shown that control sufficient to safely landthe balloon can be maintained.4.2.3.1 ClimbEach balloon must be capable of climbing at least
34、300 ft in the first minute after takeoff with a steady rate ofclimb. Compliance with the requirements of this section must be shown at each altitude and ambient temperature for whichapproval is sought.4.2.3.2 ControllabilityThe balloon shall be controllable during takeoff, climb, level flight, appro
35、ach, and landing.4.2.3.3 DescentThe following shall be measured. It must be shown that in the event of the most critical uncontrolled descentfrom either: (1) burner failure for hot air balloon, (2) valve leak for either hot air or captive gas, and (3) the maximum permittedenvelope failure as specifi
36、ed in 5.2.2. Procedures must be established for landing at the maximum vertical velocity attained andprocedures must be established for arresting the maximum descent rate within the manufacturers specified altitude.4.2.3.4 LandingIt must be shown that the pilot can achieve a landing sink rate of not
37、 more than 1 m/s.4.2.4 Stability and ControlStability and control of the balloon shall be determined at maximum gross weight, with minimumin flight turbulence/wind for:4.2.4.1 Maximum duration of envelope valve operation, during which the balloon must not enter into a dangerous descent.4.2.4.2 Minim
38、um burner fuel pressures that will arrest the maximum descent rate as determined in 4.2.3.3 and climb asdetermined in section 4.2.3.1.5. Structure Requirements5.1 Structure for Airships and Thermal Airships (except as noted):5.1.1 LoadsUnless otherwise specified, all requirements are specified in te
39、rms of limit load.5.1.1.1 Ultimate loads are limit loads multiplied by the factor of safety defined below. Loads shall be redistributed if thedeformations affect them significantly.5.1.2 Factors of SafetyThe factor of safety is 1.5, except as shown in the following:5.1.2.1 3.0 on castings,5.1.2.2 1.
40、8 on fittings,5.1.2.3 6.67 on control surface hinges,5.1.2.4 3.3 on push-pull control systems,5.1.2.5 2.0 on cable control systems, and5.1.2.6 5.0 on envelope structures (fibrous or non-metallic parts) and rigging.5.1.2.7 In applying factors of safety, the effect of temperature and other operating c
41、haracteristics, or both, that may affectstrength of the balloon must be accounted for.5.1.2.8 For design purposes, an occupant weight of at least 170 lb must be assumed.5.1.3 Strength and Deformation:5.1.3.1 The structure must be able to support limit loads without permanent deformation of the struc
42、ture.5.1.3.2 The structure must be shown by analysis, test, or analysis supported by test to be able to withstand ultimate loads withoutfailure.5.1.3.3 The structure shall be able to withstand ultimate loads for 3 s without failure when proof is by static test. When dynamictests are used to demonstr
43、ate strength, the 3-s requirement does not apply. Local failures or structural instabilities between limitload and ultimate load are acceptable if the structure can sustain the required ultimate load for 3 s.5.1.4 Proof of StructureEach critical load requirement shall be investigated either by conse
44、rvative analysis or tests, or acombination of both.5.1.5 Proof of StrengthEnvelope material, attachments, and car frame shall all be demonstrated by test to meet the load factorrequirement with the required factor of safety. This evaluation shall include suitable tear resistance testing for the enve
45、lope.5.1.6 Load Factor:5.1.6.1 Positive n = 1.5 (comprised of a maneuvering load multiplied by a gust load factor).5.1.6.2 Negative n = 0.5.1.6.3 Additional load considerations shall be evaluated for selected design airspeeds and resultant dynamic pressures.5.1.7 Design AirspeedsThe selected design
46、airspeeds are equivalent airspeeds (EAS) except as provided in specificrequirements.5.1.7.1 Design Stall Speed, V(SI)shall be calculated based on area, lift coefficient estimates, and maximum negative boyance.F2355 1235.1.7.2 Design Maximum Level Flight Airspeed, V(H)V(H) is the maximum speed obtain
47、able in level flight with all enginesoperating at maximum continuous power and the airship loaded to achieve minimum drag.5.1.7.3 Design Airspeed for Maximum Gust Intensity, V(B)V(B) shall not be less than 35 knots or 0.65 V(H), whichever isleast.5.1.7.4 Maneuver loads considering the maximum forces
48、 that can be generated by the envelope and surfaces at V(H) andmaximum control deflections, unless placarded to limit deflection at specific conditions.5.1.7.5 Gust loads of a discrete gust of 7.6 m/s (25 fps) at V(H) and 10.6 m/s (35 fps) at V(B).5.1.8 Control Surface LoadsControl surface loads on
49、the airship shall be evaluated at loads defined in flight tests of theenvelope by the envelope manufacturer.5.1.9 Ground Mooring Conditions (when equipped)An airship that is normally moored to a mooring mast when not in flight,such as overnight. The mooring mast system shall be adequate to allow the airship to swing around the mast 360 as wind directionchanges. The strength of the mast shall be sufficient to safely moor the airship in high or gust wind conditions as specified by themanufacturer. Accommodation shall be made to a
