Ultimate load factor. For example, 1/1.

Ultimate load factor. ultimate_load: ultimate load factor (default: 3. This concept is integral to limit state design, which balances safety at ultimate loads with serviceability at working loads. 6) because dead load is more predictable than live load. 5 ultimate factor and thus ultimate load cases are usually critical over the yield. B—positive limit load factor. ) The positive limit load factor is represented by the A. jetmaker The V-n diagram First, some definitions: – the maximum load that an aircraft may be expected to encounter at any time in service – n associated with limit load \ (n W=L L\) – force necessary to rupture – n associated with ultimate load \ (n W=U L\) – ultimate load/limit load > 1; usually 1. Unlike WSM, ULM doesn't rely on modular ratios, introducing safety measures through appropriate load factors—ratios of ultimate load to working load. Allowable vs ultimate load. The section titled, "Factor of Safety" -- states that a safety factor of 1. A fighter is expected to be able to pull max G every single flight so thats effectively its Servicability limit rather than its Ultimate limit. C. ultimate load factor. g. Let us take the axial force limit state to conduct a comparative example between ASD and LRFD. 5 The latter approach was chosen for ASCE 7-10. Factor of safety = yield stress working stress {\displaystyle {\text {Factor of safety}}= {\frac {\text {yield stress}} {\text {working stress}}}} The design load is the maximum load the part should ever see in service. 6 to get the service loads. See “Note” in 23. The ACI 318 Building Code provides for strength design of reinforced concrete members by use of factored loads (actual and specified loads multiplied by load factors). The load factors are all greater than 1. Failure may be the system (1) breaking into parts, (2) permanently deforming, (3) deflecting too much, etc. Ultimate Load Factor,FAA Written (Knowledge) Test Preparation. However, when proof of strength is shown by dynamic tests simulating actual load conditions, the 3-second limit does not apply. 6. Feb 1, 2008 · The way they did this was to calibrate load factors and resistance factors so that ASD and LRFD would yield the same factor of safety at a certain dead to live load ratio (don't quote me on this, but I believe it's 1 to 2). Ultimate Strength Design Method The allowable stress method has been replaced in most structural work by the ultimate strength design method, also known as the load factor design method, plastic design method, or just strength design method. 6 for strength design). Definition Under both EASA Certification Aircraft Structure Specifications (CS) 23 (Small Aeroplanes) and 25 (Large Aeroplanes) and the equivalent FAA specifications under 14 CFR Section 23/25, the Limit Load is the maximum load to be expected in service (Loads - CS 25. The applicant must determine— (a) The limit loads, which are equal to the structural design loads unless otherwise specified elsewhere in this part; and (b) The ultimate loads, which are equal to the limit loads multiplied by a 1. Since it is impossible to fully anticipate every load condition and resulting deflection in an aerospace vehicle’s operational life, the ultimate factor of safety provides additional structural capability for unanticipated excursions beyond limit load during flight operations. Jun 29, 2024 · It is defined as the ratio of the ultimate load to the limit load. 0 since we want to compare the result to the ultimate strength of the member instead of the yielding strength of the member yet we don't want yielding to occur. b. Load and Resistance Factor Design The Manual of Steel Construction LRFD, 3rd ed. Jan 30, 2019 · Ultimate Design Load: The product of the ultimate factor of safety, the fitting factor, and the limit load. Limit load factor vs ultimate load factor. In general, the allowable load is determined by taking the average ultimate load from full scale tests and dividing by a safety factor (Ω). 0G FWD Inertia Load Factor Looking at the image above, let us say the pilots are able to land this aircraft with wheels up in an emergency situation. Another section states that safety factor of 1. Definition Ultimate Load (U) represents the maximum load a beam can sustain before failure, calculated using safety factors. Oct 29, 2019 · In the V-G diagram on the opposite page, it’s depicted in orange. Also referred to as “design ultimate load. 305, paragraph 22b, of this AC concerning flight tests. 87, 1. (4) Sampling percentage; and (5) Process and material control. Ultimate wind loads follow the Load and Resistance Factor Design (LRFD) methodology, incorporating higher wind speeds to account for extreme weather conditions. The aircraft’s structure must withstand the proof load without detrimental distortion and should not fail until the ultimate load has been achieved. 5 times greater than the limit load. Calculate the weight of the fuselage of a transport aircraft based on the Raymer method Assumptions: No fuselage mounted landing gear 1 cargo door Source: Aircraft Design: A Conceptual Approach (2nd edition) Inputs: vehicle - data dictionary with vehicle properties [dimensionless] -. Static tests conducted to ultimate load must include the ultimate deflections and ultimate deformation induced by the Abstract Aerospace structures are traditionally designed using the factor of safety approach. So it is more practical to use ASD. Ulitimate load factor « Back to Glossary Index Ultimate Load Factor The Ultimate Load Factor refers to the maximum load, calculated through analysis or determined through testing, that can be applied to an aircraft or aircraft component before it undergoes physical breakdown. However, it cannot exceed the ultimate load without significant structural damage or failure Jul 10, 2009 · If proof load is "a tensile load that the fastener must support without evidence of permanent deformation," and ultimate load is a tensile load when the fastener breaks, the ultimate load must be greater than the proof load. The load Nov 4, 2014 · LRFD Effective Factor of Safety Another approach to comparing the two methods is to compute an effective factor of safety for the LRFD method that can be compared with the ASD factors of safety. Oct 30, 2024 · Ultimate Load Method (ULM) The ultimate load method (ULM) was evolved in 1950 as an alternative to the WSM. The proof load is the limit load multiplied by the proof load factor and is used to test parts of the structure before the entire spacecraft or launch vehicle is tested. B. Choose which of the following statements are CORRECT in relation to the factor of safety and ultimate load. 5 must be Ultimate load factor or the design load factor is the limit load multiplied by a factor of safety to account for material and workmanship quality, design errors, uncertainty, etc. Jan 24, 2021 · So using the actual load without factor makes sense. 52; Utility is +4. Designing for limit loads without any detrimental permanent deformation allows for some limited yielding, such as confined to the local edge of a hole. Aircraft Performance (Aerodynamic Forces) 5. Click to expand Jun 14, 2016 · Just like the aircraft loads, ultimate loads use 1. Beam Length (Len) measures the span between supports. The airplane structure must carry the ultimate loads for at least 3 seconds without collapsing, even though the members may acquire permanent deformation. Ultimate Load Factors are the limit load factors multiplied by a prescribed factor of safety. 75) -. The vertical line from point E to point F is represented on the airspeed indicator by the A—upper limit of the yellow arc. The ultimate load is dictated by the factor of safety. Jul 27, 2024 · The Ultimate Factor of Safety (FOSult) is the load for which a structure is designed for ultimate strength and must be less than the Allowable Ultimate Load. You can multiply them by 0. difference between working stress method and limit state method. A representative gust envelope for an airplane in terms of load factor versus airspeed. C—blue radial line. The up-ward ultimate load factor for acrobati (2) The seat/restraint system test re-quired by paragraph (b)(1) of this sec-tion must be conducted in accordance with the following criteria: Aviation glossary definition for: Ultimate load factorIn stress analysis, the load that causes physical breakdown in an aircraft or aircraft component during a strength test, or the load that according to computations, should cause such a breakdown. This factor is determined by the square of the ratio of Vasd/Vult which is nothing more than the inverse of the difference between the pre-ASCE 7-10 load factors for ASD and LRFD. members breaking, or the structure blowing over. You can divide through by the load factors to get Apr 11, 2025 · The Ultimate Load is a crucial concept in aircraft engineering. mass_properties. Definition The Ultimate Load is the Limit Load multiplied by a prescribed Safety Factor of 1. Worked out in equation form: 13. To easily These changes affect how you determine wind-uplift resistance. In the test (and also in practice) remember that concrete will always use LRFD and for steel you need to make a decision based on the wording. Ultimate design load – Product of the ultimate factor of safety multiplied by the limit load (i. Oct 31, 2020 · In this article, we explain method of design, what is working stress method, limit state method, and ultimate load method. For example, the ultimate tensile stress of a material can be used with the limit stress on a part and an ultimate factor of safety. C—airspeed range for normal operations. 2. In aeronautics, the load factor is the ratio of the lift of an aircraft to its weight [1][2]: § 5. Why did ASCE 7 decide to go from allowable to ultimate wind speeds? Why do we have multiple maps instead of a single map modified by an importance factor? Prior to ASCE 7-10, the Standard utilized a single map and adjusted the wind speed using a wind importance factor (I w = 0. An airplane operating at any combination of load factor and airspeed in this region is likely to experience structural damage and possible structural failure—the red region in the V-G diagram—when the ultimate load limit is exceeded. This reduction factor allows for discrepancies in the material, manufacturing process and workmanship. For Windows PCs, Mac, iPhone/iPad, Android, PocketPC, and MP3 Audio. The ultimate load is the maximum load a structure can sustain before failure, used in engineering to ensure the safe design of bridges, buildings, and mechanical components. By this definition, a structure with an FoS of exactly 1 will support only the design load and no more. Ultimate Load Factor: Typically 1. positive limit load factor. 5 safety factor on all limit cases and thus creating more load cases. wings Oct 14, 2016 · Learning Objectives Understand the differences between ultimate and nominal wind loads on buildings Review the calculations of wind pressures using ASCE/SEI 7 standards Since the release of the 2010 version of ASCE/SEI 7 standard “Minimum Design Loads for Buildings and Other Structures”, designers and contractors put effort to make sure they specify or use the right values of wind speed In “ultimate strength” design (or “load factor” design) the sections of the members are designed taking the inelastic (plastic) strains into account so as to have sufficient dependable ultimate strength to resist the design ultimate actions arising from the service loads factored so as to give an adequate margin of safety against collapse. load factor value will decrease with increasing confidence of estimated load, dead load factor will be less than live load because we can calculate the Jan 26, 2023 · S — is the standard deviation of the population of test results Design load is calculated by multiplying the characteristic load by a pre-determined reduction factor for the material the component is manufactured from. For more information about the differences between ASD and LRFD, check this article. Probabilistic approaches utilize distributions for loads and strengths. This involves combining the load and resistance factors. 5 must be multiplied by other special factors of safety. (2) For determining the loads to be applied to the inverted airplane after a turnover, an upward ultimate inertia load factor of 3. Private Pilot through ATP and mechanic. Any part of the structure of an aircraft must be able to support the Ultimate Load and, with certain exceptions, be able to do so without failure for at least 3 seconds (Strength and deformation - CS 25. Is there a historical or engineering reason they are not nicer, rounder numbers? What is the rationale that requires that specific set of structural limits? Edit: To be Factor of safety=Ultimate Load (Strength)/Allowable Load (Stress) As understood from the above equation the allowable stress is always less than the ultimate failure stress. the fitting factor should not be multiplied by the factored limit load (ultimate load) to get a "design load"; the fitting factor belongs in the margin calc explicitly. Any part of the structure of an aircraft must be able to support the limit load without permanent The results indicate that li&t airplanes traversing the wakes of currently operational heavy transport airplanes can experience loading conditions that exceed the design l i m i t and, i n some cases, the design ultimate load factors. Failures are predicted to occur in the region of intersection of the two distributions. 5 Ultimate Factor of Safety as a formal Air Corps design requirement. For light airplanes traversing the wake generated by a proposed supersonic transport airplane the design ultimate load factors can be greatly exceeded. 0g; and (iv) For airplanes with tricycle landing gear, the nose wheel strut failed with the nose contacting the ground. For some anchors, the average ultimate load and/or allowable load is also controlled by anchor displacement limits. However, its units are traditionally referred to as g, because Load and Resistance Factor Design The Manual of Steel Construction LRFD, 3rd ed. 6 = 0. Additionally, with certain exceptions, these components should be able to handle the load without any failure for at least 3 seconds. All parts must be able to carry this load without failure. 2. e. Plastic Moment (Mp) indicates the moment when the entire cross-section reaches yield stress. Then you have just one factor for calculating allowable stress and factor for weld efficiency, both of which can be multiplied, so at the end, there could be just one safety factor. 0. The definition and analysis of the V-n diagram is critical during the design of an aircraft as it affects the operation of the aircraft. This is equivalent to a load safety Mar 2, 2016 · In Load and Resistance Factor Design (LRFD), we amplify these loads to find our Ultimate Loads based on a number of "Load Combinations" outlined in the local building code (which generally reference ASCE 7-10 in the US). For example, 1/1. If nominal strength or ultimate strength are asked for use LRFD. Assumptions: All weights and thrust act through the centerlines of the components. • Aircraft could continue operation if within limit load conditions. Design ultimate load refers to the maximum load conditions a structure is designed to withstand before reaching a state of impending failure, ensuring safety against various failure modes, such as strength, overturning, and buckling. ASCE 7-05 uses a single basic wind speed map. Understanding Load Factors 2. Dec 20, 2015 · 14 CFR Subpart C Section 25 561: Ultimate Loads, 9. 625. Apr 15, 2024 · The safe, or service-loadcarrying capacity can then be determined by dividing the ultimate-load-carrying capacity by a factor of safety. AI generated definition based on § 23. 0g; and For airplanes with tricycle land-ing gear, the nose wheel strut failed with the nose contacting the ground. 15 unless the dynamic effects of failure under static load are otherwise considered. The ultimate load is the load which may occur once in the lifetime of an aircraft. These loads must be multiplied by a factor of 1. Dec 2, 2024 · This article will focus on how SkyCiv’s auto-generated load combinations feature meets the load combination equations as specified in ASCE 7-10 ASD. the ratio the values reached at a VS0 of 79 knots. 305). the ultimate load, which is the product of the limit load and the ultimate factor (usually 1. Jan 13, 2015 · In such situations, the ultimate load factor of safety ensures that the aircraft does not fail and allow the aircraft to land safely. 5 must be used, unless otherwise provided. horizontal dashed line from C to point E. This method used the ultimate load principles for design, but retained the allowable service stresses concept in the calculations. Certain loads, such as the minimum ultimate inertia forces prescribed for emergency landing conditions, are B. 0, 1. The method Relies on the ultimate strength of reinforced concrete at the ultimate load. a. 3 Ultimate Load In general, the ultimate load is the design load multiplied by a factor of safety (FOS). The structure must be able to support this load without failing. Ultimate loading is for strength design of components/elements, they are the actual loads multiples by a safety factor. 4. ,\) the loads for Aug 19, 2019 · In my own research I stepped upon an article that says that when the geotechnical engineer calculates the ultimate bearing capacity it calculates the ultimate load by multiplying the service loads with a safety factor (lets call it Fs) now for a structural engineer (such as i am) we use different load combinations to calculate the ultimate load Jul 31, 2006 · Pf is the Failure Load (or Ultimate Load) - the load at which failure occurs. The ultimate load is obtained by enhancing the service load by some factor referred to as a load factor for giving a desired margin of safety. Dec 2, 2024 · Load and Resistance Factor Design (LRFD) involves seven basic load combination equations. Aug 21, 2015 · Design MS = (Tested Ultimate - Design Ultimate)/ (Design Ultimate) But how do we find the design ultimate? From 14 CFR Subpart C Section 25-303, for aircraft the safety factor = 1. Aug 10, 2023 · Ultimate wind speed is the wind load the structure needs to be able to resist without failing, e. The factors of safety, which have no units, are often used to make the conditions match. Since the load factor represents the amount of lift being produced, it is an easy and instructive means to define the structural limits of an aircraft - \ (e. vertical solid line from D to G. The ultimate load is the design limit load multiplied by a factor of safety and is usually the most critical load in the design procedure. A. (a) Strength requirements are specified in terms of limit loads (the maximum loads to be expected in service) and ultimate loads (limit loads multiplied by prescribed factors of safety). max_takeoff: MTOW [kg] -. Each part is then subject to analysis to determine the maximum STRESS at DUL (not DLL). In engineering, the ultimate load[1] is a statistical figure used in calculations, and should (hopefully) never actually occur. Choose which of the following statements are correct in relation to the factor of safety and ultimate load. For determining the loads to be applied to the inverted airplane after a turnover, an upward ultimate inertia load factor of 3. 1 Airplane design requirements All parts of the airplane are designed so they are not stressed beyond the yield point at the limit load factor. This is the load case used to design the structure. Oct 8, 2024 · Study with Quizlet and memorize flashcards containing terms like What is true regarding the ultimate load factor?, What is true about Va as weight decreases?, Vne has to do with: and more. (b) The ultimate loads, which are equal to the limit loads multiplied by a 1. The units have to match and the load or stress conditions need to be equivalent. This means that every part of an aircraft’s structure must withstand this Ultimate Load. Jan 16, 2012 · The ultimate limit state for civil will be a safety factor on the max design load. Concrete design methods or concrete design philosophies such as working stress method, ultimate strength method, and limit state method are used for the design of reinforced concrete, Steel, and timber structures. The calculated stresses when the ultimate loads were applied are known as ultimate stress. 76; etc. 5). It w a s Jul 6, 2019 · A chart of speed versus load factor (or V-n diagram) is a way of showing the limits of an aircraft’s performance. PD is the Working Load (or Design Load or Allowable Load Feb 26, 2025 · How to calculate the ultimate load-carrying capacity of a single pile Load-Carrying Capacity Evaluating the ultimate load-carrying capacity of a single pile is one of the most important aspects of pile design, and can sometimes be complicated. Often pilots will talk about load factor in terms of “g”s - for straight and level flight, 1 \ (g\) feels like regular earth gravity, whilst an \ (n=2\) or \ (2g\) manoeuvre makes the occupants feel twice as heavy. We will explain what ultimate load factor means in Jan 4, 2016 · For more information on the aerodynamics of flight, check out the Pilot's Handbook of Aviation Knowledge. 15) and a wind-load factor (1. For this edition, the ASD wind-load factor is 1. Jun 27, 2018 · I usually go about this a different way; if I have a insert that has a safety factor of 4 and they give me a safe working load; I multiply their safe working load by the safety factor to get ultimate capacity, multiply the ultimate capacity by the failure mode phi factor, and then compare to my factored loads. Limit load vs ultimate load Design limit load vs ultimate load. The ultimate loads are the most critical loads for the design. For each building risk category, an importance factor and wind-load factor are then applied to determine ultimate wind loads. Normal is +3. vertical dashed line from E to F. B—upper limit of the green arc. The magnitude of the gust to which the airplane must be designed depends on its class and type. 75 to multiply the basic liftoff case. The diagram is called a Vg diagram—velocity versus G loads or load factor. Permanent deformation may occur though. Thus, CP 114 used a load factor (ratio of ultimate load to working load) of 2 with additional safety factor applied to material strength, to arrive at the permissible service stresses. 4, -1. Feb 18, 2015 · The terms of this equation must be consistent. Nov 4, 2014 · The factor for dead load (1. , Refer to Figure 72. Can ultimate load flight tests be used? The FAA discourages attempting ultimate load flight tests unless the applicant understands fully the risks involved, and then the FAA advises caution. The limit load on the structure is determined and the structure is then designed for FOS times the limit load – the ultimate load. Moment Ratio (k) relates plastic moments at different beam locations. Mar 8, 2005 · ultimate load factor of 75 percent of the limit load factor at VC, considering the combined effects of normal operating pressures, expected external aerodynamic pressures, and flight loads. load factor value should be more than 1. Since the load factor is the ratio of two forces, it is dimensionless. Similar to the aircraft load cases, limit cases combined with component failures are also ultimate cases with various safety factors depending on the load case. This load is generally determined from tests on the system, or from calculations based on the system's material properties (known from other tests). One of the main differences between small aircraft certification categories (normal, utility, aerobatic) is different minimum limit load factors. The diagram typically shows load factor (n) on the vertical axis and equivalent airspeed (EAS) on the horizontal axis. (b) The structure must be able to support ultimate loads without failure for at least 3 seconds. 5 x Design limit What is Design Limit? In this case, the V-N diagram of the jet was found to have a 9. ASD applies the factor to the DESIGN and LRFD applies the factor to the load. The flight operating strength of an aircraft is presented on a graph whose vertical scale is based on load factor. Limit Load Factors are the maximum load factors which may be expected during service (the maneuvering, gust, or ground load factors established by the manufacturer for type certification). Equivalent airspeed is used because it accounts for the effects of altitude and compressibility on . Load Factors The load factors are usually amplifying factors that are used in LRFD design equation to increase the loads. Ultimate load is equal to the limit load x 1. This approach enhances safety margins, making it ideal for critical infrastructure, including high-rise buildings, hospitals, and essential facilities. 0 and the strength design wind-load factor is 1. It is defined as the Limit Load multiplied by a Safety Factor of 1. Vertical load factor of 1. Service loads are the actual loads expected and are for serviceability design (that is, deflections for example) It appears the literature you have shows the ultimate (factored) loads. Nov 2, 2012 · A Factor of Safety is then applied to those loads, to determine Design Ultimate Loads (DUL), still in terms of loads and specific to each structure. Both have load combinations and both have factors to be applied. 5) So, in that sense, the ultimate load is a "fictitious" load that you design to in order to ensure safety. ” > this also bad. Aug 21, 2018 · Operational Load Factors: Limit Load Factor: The maximum load factor that an aircraft might be expected to experience once during its service life. The positive limit load factor is represented by the Ultimate load factor is the maximum load factor that the aircraft can withstand without structural failure. This requirement is outlined in the Also known as the Load Factor Method, ULM analyzes stress conditions near structural collapse, leveraging nonlinear stress-strain curves of concrete and steel. 2230 Limit and ultimate loads. (c) The applicant must multiply the highest pertinent special factor of safety in the design for each part of the structure by each limit and ultimate load, or ultimate load only, if there is no corresponding limit load, such as occurs with emergency condition loading. 5 Hence Design Ultimate = 1. envelope. Typically the Factor of Safety is 1. This is different to Allowable Stress Design (ASD Load Combinations) which is another common philosophy with its own set of load combinations. This design method does not use allowable stresses at all. If the gust is sufficiently severe, the airplane’s resulting load factor may cross over the allowable limit load. This is also commonly used in knowing the properties of metal beams. 0 (1 review) The load factor on any airplane during a constant altitude turn is determined by: Click the card to flip 👆 Jan 7, 2016 · A—ultimate load factor. 2) is lower than the factor for live load (1. It is used for instance in aerospace engineering, bridge and tunnel construction. My apologies for the length of this post. 4. 5 factor of safety unless otherwise specified elsewhere in this part. • In March 1934, Revision G of The Handbook of Instructions for Airplane Design (HIAD) established the 1. Aug 5, 2024 · V-N Diagram The V-n diagram, or the “envelope of load factor against speed,” illustrates the maximum load factors that an aircraft can safely withstand at various speeds. 5. 305 and Section 25. 5. This was done by applying a factor to the calculated ultimate wind load, Wult. The result will be the ultimate margin for Determine: 1) Before Lift Off (Orbiter hanging from ET) 2) At Liftoff 3) As fuel is burned and SSME truss increases lunch accelerations and loads also increase to a point; use a limit factor of 1. These design methods are The ultimate load is dictated by the factor of safety. Apr 13, 2016 · The fall-back in the method was that even though the nonlinear stress strain behaviour of was considered sections but the nonlinear analysis of the structural was not carried out for the load effects. Up to date for and complete with all charts and figures and professional, illustrated explanations. Jul 9, 2008 · Another note is that designing to limit load is not typically the critical condition for most materials used in aerospace as the ratio of yield to ultimate is often less than the 1. 301). It shows how much load factor can be safely achieved at different airspeeds. There will be some permanent deformation at the ultimate load factor, but no actual failure of the major load-carrying components should occur. and more. 0 load factor for limit load. Serviceabilty wind speed is less critical and is more about keeping people comfortable and maintaining the structures. 22 and represents a global measure of the stress ("load") to which the structure of the aircraft is subjected: where is the load factor, is the lift is the weight. I know that is badly phrased, but hope you get the point. This article will walk through the governing equations for single pile design as well as an example. These numbers seem arbitrary. 0g and a coefficient of friction with the ground of 0. May 12, 2019 · In the strength design method, we used load factor to increase the amount of applied load to a structure, the use of these factors is to account for uncertainties in the estimation of different loads. Each aircraft has it's own Vg Oct 13, 2023 · To ensure the part is safe at that load, we design it to the ultimate load, which is the limit load times a factor of safety (where the FS is often, but NOT ALWAYS = 1. please read the article till the end. What Is Ultimate Load Factor? In this informative video, we will break down the concept of ultimate load factor and its importance in aviation. The ultimate load factor is 1. 301 and Section 25. by the American Institute of Steel Construction requires that all steel structures and structural elements be proportioned so that no strength limit state is exceeded when subjected to all required factored load combinations. 5 must be used. 77, 0. 5 times the limit load factor, it is the load that an aircraft structure must sustain without experiencing structural failure. Thus the stress distribution at ultimate load was just the magnification of service load by load factor following the linear elastic theory. Ultimate load vs design load. In aircraft structures, the factor of safety is typically set at 1. Determine: 1) Before Lift Off (Orbiter "hanging" from ET) 2) At Liftoff 3) As fuel is burned and SSME truss increases lunch accelerations (and loads) also increase to a point; use a limit factor of 1. 5, indicating that the ultimate load is 1. (iii) Vertical load factor of 1. 8, -1. Ultimate design load = Ultimate factor of safety Limit load). 9qmat so tvg r2so6e ng 4mvwpf 9oth7 cs egqrr5 ajo