Claude Skills by ashfordeOU

Use when you must capture the system requirements from stakeholder needs and operational scenarios per ARP4754A: document the stakeholder needs, convert each operational scenario into candidate requirement statements, and record every candidate in the requirements elicitation log with its source. Assess each requirement statement against the quality criteria: atomicity (one shall clause), verifiability (measurable acceptance bound and an assigned method), unambiguity (no weasel words such as ...

Use when you must build or validate a Goal Structuring Notation (GSN) safety argument for a certification claim: decompose the top goal into sub-goals through a strategy, attach safety assessment evidence as solution nodes, record context, assumptions and justifications, and run the argument validity checks (acyclicity, exactly one top goal, every leaf goal supported by a solution, no dangling references, strategies decomposed, away-goal justification). Produces the validated argument graph w...

Use when a task concerns aircraft or vehicle conceptual design and sizing: guide the router to the vehicle-design pack: tow-estimation takeoff gross weight, weight-estimation class-I weights, payload-range-diagram payload-range trade, fuselage-sizing cabin layout, tail-sizing tail volume coefficients, landing-gear-sizing strut loads, ws-tw-trade wing loading and thrust-to-weight, fuel-tank-sizing fuel volume and ullage, inertia-estimation moments of inertia, cg-envelope static margin, mass-bu...

Use when you must run the aircraft constraint analysis matching chart in conceptual design: compute the stall constraint wing loading from the maximum lift coefficient and the stall speed, the takeoff distance constraint thrust to weight curve, the climb gradient constraint from the excess thrust and the lift to drag ratio, the cruise constraint, and the maneuvering constraint from the load factor, then assemble the feasible design region lower bounds that gate the conceptual design trade. Pr...

Use when you must build the parametric aircraft geometry in the OpenVSP style for conceptual design: define the wing planform from the span, the root and tip chords, the sweep, the dihedral and the twist, define the fuselage from its length and stationwise radii, and add the tail surfaces and nacelles, then compute the derived geometry quantities: the wing area, the aspect ratio, the mean aerodynamic chord, the wetted areas, the component volumes and the component centroids that feed the mass...

Use when the task is the payload versus range trade-off, max payload, max fuel, design range, ferry range, or reserve fuel sizing in conceptual aircraft design. Build the payload-range diagram for a conceptual transport aircraft: compute the range at the maximum payload point, the range at the maximum fuel point, the ferry range, and the payload available at the design range from operating empty weight, maximum payload, maximum takeoff weight, and fuel capacity using the Breguet range equatio...

Use when defining the design mission profile and estimating block fuel and block time for conceptual aircraft sizing: model mission segments (taxi, takeoff, climb, cruise, descent, loiter, reserve) with their distinct fuel models, compute cruise fuel from the Breguet range equation and loiter and hold fuel from Breguet endurance, model climb and descent on fuel flow and time, apply reserve fuel rules (45 minute hold at 1500 ft plus 5 percent, or FAR 121 alternate plus hold), sum segment fuels...

Use when you must estimate the takeoff gross weight in conceptual aircraft sizing: apply the fuel-fraction method to payload and class-based empty and fuel fractions, iterate the estimate to convergence, and check the weight breakdown balances. Produces the takeoff gross weight estimate, the convergence verdict, and the breakdown check that gate the sizing iteration. Trigger: takeoff gross weight, conceptual sizing, fuel fraction, empty weight fraction, sizing iteration.

Use when you must estimate the total life-cycle-cost of an aircraft program: structure the estimate into the RDT&E, production, operations and support, and disposal phases, apply a power-law CER to a phase cost driver, apply the learning curve to get the Nth unit cost and the cumulative average unit cost, escalate costs for inflation, discount future year costs to present value at the discount rate, and bound the result with an uncertainty range. Produces the phase costs, the present value of...

Use when you must estimate the direct operating cost of the aircraft: compute the block fuel cost from the fuel price, the crew cost from the crew complement, the maintenance cost from the man-hours per flight hour, the insurance cost from the annual rate and utilization, and roll the elements into the cost per flight and the cost per flight hour. Produces the DOC breakdown and the per flight hour cost that gate the operating economics assessment. Trigger: direct operating cost, block fuel co...

Use when you must compute parametric cost estimates for an aircraft development and production program: derive the learning curve exponent from a learning curve percentage, apply the learning curve to get unit cost and cumulative production cost, estimate development cost from airframe mass with a weight-based cost estimating relationship, and roll the recurring and non-recurring pieces into a total program cost. Produces the unit cost, the cumulative learning factor, the production total, an...

Use when you must analyze the center-of-gravity envelope of a vehicle: derive the cg station from component weights and arms, check the operating cg against the forward and aft limits, test an operating point against the envelope polygon in the cg versus weight plane, compute the static margin from the neutral point normalized by the mean aerodynamic chord, and track the cg excursion as the fuel burns between loading states. Produces the cg station, the limit verdict, the polygon membership w...

Use when you must estimate mass properties for vehicle design: compute moments of inertia from masses and radii of gyration, move inertia between axes with the parallel axis theorem, and check the gyration radius against the component dimension. Produces the inertia estimates, the parallel axis transfers, and the gyration sanity verdict that feed the loads analysis. Trigger: mass properties, moment of inertia, radius of gyration, parallel axis theorem, inertia estimation.

Use when you must build the vehicle mass budget for the conceptual design: allocate the subsystem masses, apply the growth allowance and the contingency margin policy, roll up the total estimated mass, and check the margin-backed total against the MTOW target. Produces the mass breakdown, the total mass with margin, and the within-target or over-target verdict that gate the weight control plan. Trigger: mass budget, growth allowance, contingency margin, MTOW target, mass breakdown.

Use when you must plan a design of experiments (DOE) for an aircraft or spacecraft conceptual design study and analyze the runs: build the coded design matrix with a full factorial, a fractional factorial two-level half-fraction with its defining relation and alias structure, a seeded latin hypercube sample, or a central composite design around the baseline point, then compute the per-factor main effects, the two-factor interaction effects, and the factor screening ranking. Produces the coded...

Use when you must set up a multidisciplinary optimization (MDO) loop for an aircraft or spacecraft: define the design variables, the objective function, and the constraints, identify the coupled disciplines (aerodynamics, structures, propulsion, trajectory), choose a monolithic or distributed architecture, and run the analysis loop that iterates the coupling variables to convergence with a fixed-point scheme and a sensitivity check. Produces the converged coupled state, the constraint feasibi...

Use when you must build and validate an approximation model of an expensive aerospace analysis from sampled design data: assemble the full quadratic basis, fit a ridge-regularized quadratic response surface, fit a Gaussian radial basis function interpolant, predict the response at new design points, run a leave-one-out cross validation on both models, and recommend the surrogate with the lower estimated prediction error. Produces the fitted coefficients or weights, the cross-validation and in...

Use when you must size the bootstrap air-cycle cooling pack thermodynamics for the ECS cooling load: compute the compressor exit state from the pack-inlet bleed condition, pressure ratio and isentropic efficiency, cool the discharge through the ram-air heat exchanger at a given effectiveness, expand through the cooling turbine to cabin pressure, close the two-wheel ACM shaft balance, and turn the turbine exit temperature into delivered cooling against the cabin design temperature. Produces co...

Use when you must analyze the aircraft electrical power system load: roll up consumer apparent power (kVA) with each consumer duty cycle into the continuous load, apply the diversity factor for the coincident peak, total the essential load from the named essential consumers at full steady power, check the generator rating against the single-generator-out case where remaining capacity must cover the essential load, and report the load fraction against the installed capacity. Produces the conti...

Use when you must size the aircraft supplemental oxygen system: computing passenger continuous-flow chemical generator demand and unit count, crew diluter-demand gaseous oxygen requirement, converting standard-litre demand volumes to oxygen mass at standard conditions, and sizing crew gaseous oxygen bottle volume from the ideal gas law at the service pressure and storage temperature. Produces the passenger and crew oxygen demands, the generator count, the crew bottle volume and the stored oxy...

Use when you must compute the APU fuel burn: take the generator electrical output and the bleed mass flow at a fixed load point for a conceptual aircraft or rotorcraft auxiliary power unit, convert the electrical output into generator shaft power through the generator efficiency, convert the bleed mass flow into its load-compressor pumping-power equivalent with the adiabatic compressor work relation at the stated pressure ratio, sum both into the total equivalent shaft load, and convert that ...

Use when you must size the cooling airflow for the avionics and equipment bay: rolling up the bay heat load from the LRU heat dissipations, sizing the bay cooling mass flow from the allowable cooling air temperature rise so the bay exhaust temperature stays at or below the LRU inlet air temperature limit, converting the mass flow to the volumetric flow and to cubic feet per minute, and checking each LRU case temperature against its case limit from the dissipated power and the case to air cond...

Use when you must size the traction battery pack of an electric aircraft or eVTOL from the mission energy and power requirements: convert the mission draw into the required pack energy with the depth of discharge limit and discharge efficiency, add the reserve, lay out the series and parallel cell counts for the target pack voltage, check the discharge C-rate against the cell limit, verify the minimum cell voltage under peak load against the cutoff with the cell internal resistance, and estim...

Use when you must size the aircraft bleed air system: roll up the total bleed offtake mass flow from the fixed consumer demands (ECS pack flows, wing anti-ice flow, pressurization trim flow), split the offtake per engine, compute the bleed thermal budget the precooler must reject between the bleed supply temperature and the consumer supply temperature, and size each engine bleed duct diameter from compressible pipe flow at a fixed design Mach number. Produces the total and per-engine offtake ...

Use when you must size the aircraft wheel brake system from the kinetic energy it must absorb: compute the rejected-takeoff (RTO) brake energy at the decision speed and the landing-stop brake energy at the touchdown speed, divide the total energy over the braked wheels, estimate the required carbon heat sink mass per brake from the allowable temperature rise and the specific heat, check the temperature rise of the selected heat sink, and estimate the braking distance at the design deceleratio...

Use when you must size the cabin outflow valve: compute the choked-flow mass flux G = p sqrt(gamma/(R T)) (2/(gamma+1))^((gamma+1)/(2(gamma-1))) at the cruise cabin condition, divide the governing pack inflow by that flux for the outflow valve effective area, and size the pressure-relief valve effective area to dump the same pack flow at the 8.9 psi differential pressure clamp ceiling. Produces the choked-flow mass flux, the effective area and equivalent diameter for the outflow and relief ca...

Use when you must size the canard of a canard-configured aircraft: compute the required canard area for a target canard volume coefficient from the canard arm and the wing reference geometry, derive the trim lift share carried by the forward canard from the longitudinal geometry, resolve the canard and wing lift coefficients at the trim condition, and run the stall precedence check that the canard reaches maximum lift before the wing so the nose drops instead of pitching up. Produces the cana...

Use when you must size a freight cargo compartment and its cargo door around standard unit load devices: look up public ULD envelope dimensions from the module catalog, check whether a ULD cross-section passes through a cargo door with the rotated orientation tried, pick the largest-volume ULD that fits a door, lay out ULD positions with a deterministic 2D strip layout and aisle allowance, compute the required cargo volume from payload mass and density, and report the adequacy verdict. Produc...

Use when you must predict the airframe structural group weights at the class-II level from geometry and design loading: evaluate the statistical wing-group-weight regression on the planform area, aspect ratio, sweep, thickness ratio and design load factor, the horizontal-tail-group-weight and vertical-tail-group-weight regressions on the tail planforms, and the fuselage-group-weight regression on the wetted area, fineness ratio and design gross weight, with the limit load factor scaled to ult...

Use when the task is control surface sizing, aileron sizing, elevator area, rudder area, roll rate requirement, pitch moment authority, yaw authority, hinge moment, or deflection limits. Size the aileron, elevator, and rudder control surfaces of a fixed-wing aircraft from control power: the aileron area from the roll rate requirement with the roll damping derivative, the elevator area from the pitch moment requirement with the elevator effectiveness, the rudder area from the yaw moment requir...

Use when you must size an aircraft electrical wire run: select the smallest conductor gauge whose bundled ampacity at the ambient temperature meets the continuous load with the bundle and temperature derating applied, check the round-trip voltage drop over the run length at the load current against the bus tolerance, compute the percentage drop, and report the selected gauge, its ampacity margin, the voltage drop and the percent-drop verdict. Produces the conductor gauge selection and the dro...

Use when you must configure passenger emergency exits against the discrete exit-type rules: look up each exit type's minimum rectangular opening and per-exit seating credit from the constant table, verify that the exits on each side of the fuselage alone cover the passenger capacity, check the capacity-band minimum exit counts and minimum types, apply the two-C-or-larger rule when a type-a, type-b or type-c exit is installed, check the 60-foot adjacent-exit spacing rule on the same side with ...

Use when you must size the propulsion system for the transport aircraft: compute the sea level static thrust from the design thrust to weight ratio and the takeoff gross weight, lapse the thrust to the cruise and top of climb altitude through the ISA density ratio, apply the installed thrust loss for the takeoff thrust, check the thrust margin against the cruise drag, estimate the engine weight from the engine thrust to weight ratio, and split the total thrust across the number of engines. Pr...

Use when you must size the environmental control system of a transport aircraft: compute the cabin ventilation fresh air flow from the occupant count and per-occupant rate, roll up the cabin heat load from occupants, solar, equipment and skin with a design margin, derive the pack cooling airflow from the heat load and the supply air temperature rise, take the pack airflow as the governing maximum of fresh and cooling flow, and build the cabin pressurization schedule that holds the design cabi...

Use when you must size the aircraft fire protection extinguishing agent: fix the protected zone (Class C cargo compartment or powerplant fire zone), take zone free volume and agent concentration by volume, compute total-flooding agent mass and closure check from agent vapor specific volume at discharge temperature, roll up installed agent from bottle and shot count, and set discharge nozzle count from zone coverage. Produces the required agent mass per shot, the installed agent mass, the clos...

Use when you must size the aircraft fuel feed system between the tank and the engine: the per-engine feed flow from the takeoff fuel flow demand, the feed line velocity and Reynolds number, the line pressure loss from the Darcy friction factor (laminar 64/Re, turbulent Blasius) with the major loss over the line length and the minor losses from the fitting loss coefficient, the static head gain from tank to pump, and the net positive suction head available at the engine-driven pump inlet again...

Use when you must size the fuel jettison system: from the maximum takeoff weight and the maximum landing weight, compute the fuel mass that must be dumpable and the required average jettison rate to reach the landing weight within the 15-minute limit of FAR 25.1001, apply the design margin to the required rate, split the design flow over the dump mast count, and verify the resulting time to landing weight against the 900 s limit. Produces the dumpable fuel mass, the required and design jettis...

Use when you must predict the fuel system group weight at the class-II level for the weight statement: evaluate the statistical fuel system weight regression of the transport integral-tank fuel system on the total fuel weight and the tank arrangement, the fixed 80 lb count allowance per tank and engine unit plus the 15 lb volume term scaling with the square root of the tank count and the cube root of the fuel quantity at the published fuel specific weight, and sum the terms into the fuel syst...

Use when you must size the fuel tank inerting system at the conceptual level: model the ullage as a well-mixed volume washed by nitrogen-enriched air (NEA), compute the required NEA flow from the exponential oxygen decay C(t) = C_NEA + (C0 - C_NEA) exp(-Q t / V), and solve the flow that reaches a target oxygen fraction within a required time Q = (V/t) ln((C0 - C_NEA)/(C_tgt - C_NEA)). Produces the required NEA flow in m3/s and in SCFM, the ullage oxygen fraction at the required time, the wash...

Use when you must size the fuel tanks for the aircraft: convert the fuel mass to the fuel volume with the fuel density, add the ullage allowance to get the required tank volume, and check it against the available volume in the wing and fuselage tanks. Produces the usable fuel volume, the required tank volume with ullage, and the fits verdict that gate the fuel system sizing. Trigger: fuel tank sizing, ullage, fuel volume, usable fuel, tank capacity.

Use when you must size a transport fuselage from the payload: compute the cabin length from the seat count and the seat pitch, compute the cabin width and the fuselage diameter from the seats-abreast layout and the aisle width, judge the overall fuselage length to diameter ratio against the typical transport band, and check the underfloor cargo volume against the required baggage volume. Produces the cabin length, fuselage diameter, and cross-section layout that feed the conceptual sizing loo...

Use when you must size a hydraulic actuator: the piston area and bore diameter from the actuator load and system pressure with the pressure-margin factor and mechanical efficiency, the rod-side annulus area and retract capability, the rod diameter from Euler column buckling over the extended rod length with the design factor, the nearest preferred bore and rod diameters at or above the requirements, and the actuator mass estimate. Produces the bore and rod diameters, the annulus area, the buc...

Use when you must size the aircraft hydraulic power system from actuation demand: actuator flow from piston area and rod speed, worst-case simultaneous demand, pump flow and drive power from system pressure, flow and efficiency with leakage make-up, the emergency accumulator gas volume between charged and depleted pressure from the adiabatic gas law given the usable volume, and the reservoir volume from leakage make-up over a hold time with margin. Produces the per-actuator flow, the simultan...

Use when you must size the thermal ice protection system for an aircraft surface in FAR/CS 25 Appendix C continuous maximum icing: choose evaporative anti-icing, running-wet anti-icing or cyclic de-icing, compute the protected area from the icing-critical geometry, estimate the droplet catch efficiency from MVD and airspeed, compute the evaporative heat flux and running-wet surface temperature with the freezing fraction, size the electrothermal power or bleed air mass flow, and return the pro...

Use when you must select the vertical landing gear geometry of a tricycle-gear aircraft at the conceptual level: solve the static-ground-line from the tail-cone-clearance margin at the design rotation attitude about the main gear contact, compute the main-gear-height and the nose-gear-height that level the cabin waterline over the wheelbase, verify the nacelle and propeller clearances at the level and rotated attitudes, and check the nose gear static load share at the design CG. Produces the ...

Use when you must lay out the landing gear arrangement of an aircraft against its center-of-gravity envelope: compute the tipback angle at the aft CG limit about the main gear contact, the tail strike clearance angle at rotation, the lateral turnover angle from the wheel track at the forward CG limit, and the nose gear load fraction band across the CG travel. Produces the three layout angles in degrees, the nose gear load fraction at the forward and aft CG limits with band verdicts, and the m...

Use when you must size the landing gear retraction mechanism: the gear moment about the retract pivot from gear weight and CG arm, the retraction actuator force from that moment and actuator arm with a design factor, the actuator stroke from the four-bar linkage geometry between down-locked and up-locked positions via the law of cosines, the down-lock and up-lock hold loads at their lock arms, and the gear bay stowage fit of the wheel and folded strut envelope. Produces the retraction moment,...

Use when you must size the landing gear for an aircraft at the sizing level: split the maximum landing weight over the struts, compute the nose and main gear loads from the CG position and the wheelbase, size the shock absorber stroke from the sink speed and the landing load factor, and check the tire rating margin. Produces the static loads, the required stroke, and a gear sized or tire overloaded verdict that gate the landing gear configuration. Trigger: landing gear, strut load, wheelbase,...

Use when you must predict the landing gear group weight at the class-II level for the weight statement: evaluate the statistical main-gear-group-weight regression on the design landing weight, the ultimate landing load factor and the main gear strut length with the wheel, strut and stall speed terms, evaluate the nose-gear-group-weight regression on the design landing weight, the ultimate landing load factor and the nose gear strut length with the nose wheel count, with the limit landing load...

Use when the task is nacelle geometric sizing, inlet capture and highlight sizing, cowl thickness, wetted area, or nacelle drag bookkeeping for a high bypass turbofan. Size the engine nacelle geometry for a turbofan: derive the fan face area and diameter from the fan mass flow, density, Mach number and temperature; enlarge the fan face to the inlet highlight area with the lip area ratio; compute the free stream capture area and the A0/A1 capture area ratio at the flight Mach number; scale the...