Claude Skills by ashfordeOU

Use when you must assess the static speed stability of a fixed-wing transport from its trim drag balance: build the thrust required curve versus true airspeed from the drag polar, its zero lift drag and induced drag factor, derive the curve slope dT/dV, classify each level flight trim speed as speed stable or speed unstable on the back side of the curve, locate the minimum drag speed boundary where the slope crosses zero, and compute the slow flight stability margin between a proposed minimum...

Use when you must compute takeoff performance from the aircraft weight, wing area, and thrust: determine the stall speed from wing loading and density, apply the liftoff speed factor, and estimate the ground roll distance with rolling friction. Produces the stall speed, the lift off speed, and the ground roll distance that gate the takeoff field-length check. Trigger: takeoff, ground roll, lift off speed, stall speed, wing loading.

Use when you must compute the thrust required and power required curves for level unaccelerated flight from the drag polar: derive the total drag coefficient from the zero lift drag coefficient and the induced drag factor, compute the thrust required and the power required at a given equivalent airspeed, weight, wing area, and air density (for example the sea level density 1.225 kg/m^3), and locate the characteristic points: the minimum drag speed where the parasite drag equals the induced dr...

Use when you must compute sustained turn performance for a fixed-wing aircraft: derive the load factor from the bank angle or the bank angle from the load factor, compute the turn rate and turn radius at a given airspeed, and check whether the available thrust sustains the turn against the increased drag. Produces the load factor, bank angle, turn rate, turn radius, and the sustained verdict that gate the maneuvering performance assessment. Trigger: turn rate, turn radius, bank angle, load fa...

Use when you must resolve the wind triangle for a fixed-wing aircraft: decompose the wind into the headwind, tailwind, and crosswind components along the track, combine the true airspeed with the wind components to find the groundspeed, derive the wind correction angle needed to hold the track against the crosswind, and convert a leg distance into the enroute time at the resulting groundspeed. Produces the wind components, the groundspeed, the wind correction angle, and the enroute time that ...

Use when you must assess a low-altitude windshear or microburst encounter on fixed-wing aircraft performance and choose the escape response: compute the windshear F-factor from thrust, drag, weight and the along-track headwind shear rate, or from the headwind gradient and the downdraft; classify the shear severity against the typical escape-guidance thresholds; compute the energy height loss rate and the altitude loss over the encounter; check whether the aircraft can out-climb the downdraft ...

Use when you must assess the aileron control reversal of a wing from its torsional stiffness: compute the reversal dynamic pressure q_rev = k_t / (C_l_alpha * eta * S * c * e) from the torsional stiffness about the elastic axis, the lift curve slope, the aileron effectiveness factor, the wing area, the mean chord, and the elastic axis to aerodynamic center offset, convert it into the reversal true airspeed with V_rev = sqrt(2 q_rev / rho) at the flight density, evaluate the aileron effectiven...

Use when you must size and verify the elevator authority and hinge moment requirements of a transport-category airplane: compute the dynamic pressure and the hinge moment coefficient from the tab and angle derivative terms, the hinge moment from the elevator area and chord, the stick force from the gearing arm, the tail volume coefficient and the elevator pitching moment derivative, the elevator deflection needed to trim and to reach a maneuver load factor, the authority margin against the ma...

Use when you must assess whether a T-tail or aft-fuselage-mounted-tail airplane can enter a deep stall, a self-sustaining high-angle-of-attack trim beyond the stall sometimes called alpha lock, and whether the elevator retains pitch-down authority to recover. Compute the viscous stall angle from the wing lift slope, model the loss of horizontal-tail effectiveness in the wing or fuselage wake with a tail blanking factor, add the separated-flow wing-body pitch-up that rises after the stall and ...

Use when you must evaluate the dynamic stability of an aircraft: compute the longitudinal stability derivatives (pitch stiffness M_alpha, pitch damping M_q, vertical force Z_alpha), estimate the short period and phugoid natural frequency and damping ratio from those derivatives, classify the lateral-directional modes (Dutch roll, roll subsidence, spiral) from the eigenvalues, and check each dynamic stability criterion: the short period damping band, the minimum Dutch roll damping, the spiral ...

Use when you must assess the lateral-directional stability of an aircraft: compute the directional stability derivative Cn beta from the vertical tail volume coefficient, fin efficiency, and fin lift slope; compute the dihedral contribution to the roll stability derivative Cl beta from the wing dihedral angle and lift coefficient; and characterize the lateral-directional modes: Dutch roll frequency and damping ratio from the simplified yaw sideslip model, the roll mode time constant from the ...

Use when you must assess static longitudinal stability of an aircraft: compute the neutral point from the wing aerodynamic center, the tail volume coefficient, the lift slope ratio, and the downwash gradient; derive the static margin at the current center of gravity; and determine whether the aircraft is longitudinally stable for pitch stability. Produces the neutral point location, the static margin, and the stability verdict that gate the longitudinal stability analysis. Trigger: static mar...

Use when you must analyze the phugoid, the long-period longitudinal mode of an aircraft, with the Lanchester approximation from the cruise speed and the lift-to-drag ratio alone: compute the phugoid natural frequency omega_p = g0 * sqrt(2) / V and period, the drag-damping ratio zeta_p = 1 / (sqrt(2) * (L/D)), the damped frequency, the time to half amplitude, and the cycles to half amplitude of the airspeed oscillation, and check the small-damping validity floor of L/D 8. Produces the phugoid ...

Use when you must analyze the short-period longitudinal mode of an aircraft: convert the dimensionless stability derivatives C_m_alpha, C_m_q, C_m_alphadot, C_Z_alpha and C_Z_q to dimensional per-unit-mass derivatives with the aerodynamic timescale, compute the short-period natural frequency and damping ratio from the two-DOF pitch model, verify the phugoid separation assumption, and check the mode against the Level 1 flying qualities damping and frequency boundaries for the flight phase cate...

Use when the task is spin recovery, autorotation, spin modes, incipient spin, flat spin, or post-stall departure recovery. Analyze spin entry, developed spin modes, and recovery controls for a stalled aircraft: compute the post-stall autorotative band and stall penetration, estimate the spin descent rate and rotation rate from weight, wing area, and spin drag, classify the spin mode as steep or flat, and size the altitude lost and rotation stop time during spin-recovery. Trigger: spin recover...

Use when you must estimate the aerodynamic stability derivatives of an aircraft from its geometry in AVL style: estimate the wing and tail lift curve slopes from the planform aspect ratio, the quarter-chord sweep, and the Mach number; estimate Cm_alpha from the tail volume coefficient and the downwash gradient; estimate the lateral-directional derivatives Cn_beta, Cl_beta, Cl_p, Cl_r, Cn_p, and Cn_r from the vertical tail geometry, the wing dihedral, and the sweep contribution; and derive the...

Use when you must analyze the stick fixed trim condition of a fixed-wing aircraft: compute the trim lift coefficient from the weight, density, true airspeed, and wing area, derive the elevator deflection required to trim from the pitching moment coefficients and the elevator effectiveness, find the trim speed for a given trim lift coefficient in level flight, and check whether the total pitching moment closes at zero for the trimmed verdict. Produces the trim lift coefficient, the elevator de...

Use when a task concerns flight test operations: route to the flight-test-operations pack: envelope-expansion corner speed, load-factor-envelope load factor, v-speeds cert speeds, stall-speed-determination stall speed, stall-characteristics-testing stall behavior, accelerate-stop-distance rejected takeoff, takeoff-distance-determination takeoff distance, landing-distance-determination landing distance, glide-flight-test glide, flight-loads-survey strain calibration, flutter-testing flutter ma...

Use when you must plan and analyze the buffet boundary flight test for a transport airplane: schedule pull-up and steady-turn test points across a Mach sweep at constant altitude, detect buffet onset from the vertical accelerometer RMS rise above the 0.02 g threshold, convert the onset load factor to the boundary lift coefficient at each Mach, fit the buffet boundary line over the tested Mach band, and compute the buffet margin at the cruise Mach against the maneuver buffet target load factor...

Use when you must plan flight test envelope expansion: compute the corner speed (maneuvering speed VA) from the stall speed and the limit load factor, classify airspeeds into the flight test speed categories, and size the expansion steps against the load factor envelope. Produces the corner speed, the airspeed classification per test point, the per-step speed increment, and the load factor limit verdict that gate the expansion program. Trigger: envelope expansion, corner speed, airspeed class...

Use when you must build a flight test loads survey: calibrate strain gauge load stations against applied ground loads, compute the calibration factor and the measured load at each station, and reduce the load factor versus speed survey points (symmetric and rolling maneuvers) to lift coefficient and load factor for comparison with the predicted loads envelope. Produces the strain calibration factor, per-point measured loads, the survey load factor and lift coefficient, and the maneuver point ...

Use when the task is post-stall envelope definition, AoA instrumentation calibration, or deep stall testing. Plan and run the high angle of attack flight test: calibrate the angle of attack sensor position error against a tower fly-by or trailing cone reference, size the post-stall and deep stall test points across configurations and center of gravity conditions, estimate the stall warning margin against the required margin in the certification context, and judge the departure resistance and ...

Use when you must categorize an icing encounter and plan the icing certification flight test campaign for a transport airplane against the FAR/CS 25 Appendix C icing envelopes: judge the continuous maximum and intermittent maximum regime membership from liquid water content, median volumetric diameter and total air temperature, rate the icing encounter severity for the flight test log, screen the natural icing search conditions against the freezing level and the forecast liquid water content,...

Use when you must build the flight test load factor envelope (V-n diagram): compute the stall speed boundary from the wing loading and the maximum lift coefficient, derive the corner point speed at the positive limit load factor, compute the discrete gust line increment in the FAR 25.341 form, and judge the envelope against the placard speed and the transport positive and negative limit load factors. Produces the stall speed boundary, the corner point speed, the gust load factor increment, an...

Use when the task is spin flight testing, spin recovery, spin resistance, or recovery parachute planning. Plan and execute the spin flight test: build the spin test point matrix across configurations, center of gravity positions, weights, and altitudes, flag the points outside the approved CG envelope, classify the entry, incipient, and developed spin phases from the rotation, apply the recovery control procedure and check the recovery against the turn count and altitude loss limits, decide w...

Use when you must plan and gate the stall characteristics flight test: build the stall test matrix across configurations and power settings, pick the entry technique (gradual deceleration at one knot per second, power-on, turning, accelerated), compare the natural stall with the accelerated stall at the entry load factor, verify the stall warning onset (buffet or stick shaker) against the required margin, and judge the recovery characteristics (altitude loss, pitch-up, roll-off, departure res...

Use when you must assess the structural coupling of the flight control system with the airframe structural modes from measured frequency response data: compute the gain margin from the amplitude response at the phase crossing and the phase margin from the phase response at the gain crossing, plan the frequency response testing of the closed-loop control system with swept sine, chirp, or impulse excitation across the flight envelope, and judge the margins against the typical 6 dB gain margin a...

Use when you must compute the v-speeds set for a flight test: derive the vref reference landing speed as 1.3 times the vs0 stalling speed in landing configuration, the v2 takeoff safety speed as 1.2 times the vs1 stalling speed in takeoff configuration, and the vr rotation speed as 1.1 times vs1, then validate the speed ordering and check the vno normal operating limit and the vne never exceed speed. Produces the vref, v2, and vr speeds, a validated v-speeds dict, and the vne guard verdict wi...

Use when you must predict and check the minimum control speed Vmc of a multi-engine airplane for the engine-inoperative flight test: identify the critical engine from the engine-out yawing moment geometry, build the asymmetric yawing moment from the operating-engine thrust at the failed engine lateral arm plus the windmilling drag contribution, solve the rudder authority limited speed, apply the rudder pedal force criterion with the boost factor against the 150 lbf pedal limit, and apply the ...

Use when you must reduce the engine-failure ground roll demonstration runs of a transport airplane flight test to the ground minimum control speed Vmcg in the spirit of the FAR/CS 25.149 ground leg method, summary-only: build the asymmetric yawing moment from the failed engine thrust at its lateral arm, apply the nosewheel steering authority below the steering cutout speed, solve the steering-free rudder authority limited and 150 lbf pedal force limited ground speeds with the boost factor, cl...

Use when you must reduce the landing-configuration approach-cut demonstration runs of a multi-engine transport airplane flight test to the approach and landing minimum control speeds VMCL and VMCL-2 in the spirit of the FAR/CS 25.149(f)/(g) method, summary-only: build the asymmetric yawing moment of the critical-engine cut over the operating engine set, solve the rudder authority limited and 150 lbf pedal force limited airspeeds with go-around thrust, classify each run by the bank-5-degree an...

Use when you must reduce the takeoff rotation runs of a transport airplane flight test to the minimum unstick speed Vmu in the spirit of the FAR/CS 25.107(b) method, summary-only: classify each measured rotation run against the certified tail-strike rotation limit, correct each liftoff speed from the test weight, altitude, temperature, and flap setting to the reference conditions, and take the minimum corrected speed of the limit-reaching runs as the Vmu verdict with the no-unstick and premat...

Use when you must reduce an in-flight vibration survey: extract the per-rev order amplitudes from measured accelerometer time histories with a synchronous DFT over integer-revolution windows, compute the windowed total RMS survey level, combine the order components by root-sum-square, and gate each survey point against the declared vibration limit and the 1P trim limit. Produces the per-order amplitudes, the total level, the RSS check, and the pass or needs-trim verdicts for rotorcraft main-r...

Use when you must assess flutter clearance for a flight test: compute the required flutter speed V_F_required as 1.2 times the design dive speed V_D, extrapolate the measured flutter speed from the damping versus test speed trend with a linear least squares fit and its zero crossing, check the frequency separation between structural modes against the 10 percent minimum, and judge the flutter margin ratio and the damping margin at the maximum test speed. Produces the required flutter speed, th...

Use when you must plan or analyze a ground vibration test (GVT) for flutter clearance: estimate modal damping from the half-power bandwidth of the frequency response function (FRF) peak, judge whether an FRF peak qualifies as a mode candidate, compute the FFT frequency resolution for the test setup, and check the detected mode count against the pre-test expectation. Covers excitation methods (shakers, impact hammers, sine sweep, random), mode extraction (peak picking, circle fit, curve fittin...

Use when you must assess a limit cycle oscillation (LCO) during a flight test flutter clearance campaign: compute the damping ratio from the log decrement of the decaying oscillation, estimate the amplitude growth rate from the amplitude time history, judge whether the oscillation is sustained or diverging at a fixed airspeed, and compute the amplitude margin against the limit amplitude. Covers freeplay and nonlinear damping effects on LCO onset below the linear flutter speed, and the amplitu...

Use when you must compute the rejected takeoff accelerate stop distance for a flight test: accelerate the airplane to the decision speed V1, stop it with the braking deceleration, and check the total against the available runway length. Produces the accelerate distance, the stop distance, and the runway fits verdict that gate the rejected takeoff field length assessment. Trigger: rejected takeoff, V1 decision speed, braking deceleration, accelerate stop distance, runway length, balanced field...

Use when you must run a climb performance flight test on a fixed-wing aircraft: measure the rate of climb in feet per minute from the pressure altitude change over a timed steady climb segment, correct the measured rate of climb for the test weight and the density altitude to the reference condition, convert the pressure altitude rate to the geometric rate with the outside air temperature, determine the service ceiling and the absolute ceiling where the best rate of climb decays to the thresh...

Use when you must plan and reduce a cruise performance flight test: schedule level cruise points across a Mach sweep at constant altitude with stabilized fuel flow runs, correct measured fuel flow from the test weight to the reference weight with the square-root weight correction, convert corrected fuel flow and true airspeed into range performance, fit a quadratic range performance curve versus Mach, and read off the maximum range cruise Mach at the vertex and the long range cruise speed at ...

Use when you must reduce the engine-out takeoff flight test: locate the engine failure point in the measured ground run at the failure speed VEF, add the V1 recognition time segment, integrate the continued takeoff to the 35 ft obstacle at the measured engine out climb rate, and set the decision speed V1 at the balanced field intersection where the stop distance curve equals the continued engine out takeoff distance curve. Produces the engine failure distance, the recognition distance, the co...

Use when you must run an engine flight test to determine the installed thrust and verify the engine performance at altitude: derive the thrust from the rate of climb or the level acceleration and the measured drag, compute the fuel flow from the thrust specific fuel consumption, check the exhaust gas temperature margin against the limit, correct the EGT to the ISA temperature, scale the sea-level thrust to the test altitude with the density ratio, time the acceleration and deceleration transi...

Use when you must reduce a fuel jettison flight test demonstration: least-squares fit the telemetered fuel-weight-vs-time samples taken while the dump runs, read the measured average dump rate from the fitted slope, extrapolate the time from the takeoff weight down to the landing weight at that measured rate, judge the PASS or FAIL verdict against the 900 s limit, and check the measured rate against the design-side required rate. Produces the fitted slope, intercept and R^2, the measured dump...

Use when you must run a glide flight test at idle thrust to measure the sink rate and the lift to drag ratio of an airplane: derive the sink rate from the altitude loss and the segment time, compute the lift to drag ratio from the true airspeed and the sink rate, correct the results for the weight change, the air density, and the residual idle thrust, and locate the best glide speed. Produces the measured and corrected sink rate in m/s, the lift to drag ratio, and the best glide speed that ga...

Use when you must reduce an in-flight engine restart demonstration: fit the least-squares windmill N2 regression against true airspeed from the windmill survey, read the minimum relight airspeed where the fitted N2 line crosses the required relight threshold, summarize the starter-assisted relight time-to-idle samples against the type-data limit per altitude band, and combine the band verdicts with the airspeed into the overall restart-demonstration verdict. Produces the regression slope, int...

Use when you must determine the landing distance for a flight test: derive the approach speed Vref from the reference stall speed with the 1.23 factor, add the airborne flare segment and the braking ground roll, apply the 1.67 certification field length factor, and check the result against the available runway length. Produces the airborne and ground roll legs, the total demonstrated landing distance, the certified field length, and the runway fits verdict that gate the FAR 25.125 landing per...

Use when you must reduce an accelerated level flight run from a fixed-wing aircraft flight test: convert the calibrated airspeed samples to true airspeed with the ISA density at the test altitude, smooth the airspeed trace with a moving average, compute the acceleration from the smoothed trace with central differences, and evaluate the specific excess power by the total energy method, P_s = dh/dt + V a / g. Estimates the excess thrust at the test weight from P_s and, when the drag polar is pr...

Use when you must reduce a rotorcraft power-off autorotation demonstration flight test: least-squares fit the telemetered pressure-altitude samples against time over the steady autorotative descent, read the measured sink rate from the fitted slope, run the rotor-RPM checks across the entry decay, steady descent and flare recovery against the declared floor, band and recovery target, compute the altitude lost to the recovery from the flare-initiation and re-established level-flight altitudes,...

Use when you must reduce a rotorcraft forward-flight climb flight test from measured data: reduce the measured rate of climb from the least-squares pressure-altitude windows of the steady climb runs across the airspeed sweep, convert the calibrated airspeeds to true airspeed at the test density, correct the measured rate of climb to the reference weight and the standard day with the rho/weight ratio law, identify the best-rate-of-climb speed Vy at the peak of the corrected rate-of-climb curve...

Use when you must reduce a rotorcraft level-flight performance flight test from measured data: convert measured main rotor torque and rotor speed samples into shaft power across a forward-flight speed sweep, correct the measured power-required polar to a reference weight and standard day with the induced and profile power split, fit the corrected polar, and read off the best-endurance speed at the minimum-power point, the best-range speed at the tangent from the origin, and the maximum level-...

Use when you must reduce a rotorcraft height-velocity (dead-man-curve) demonstration flight test from the hover and low-speed engine-failure runs: measure the recognition delay, the height loss and time to establish autorotation and complete the flare or landing from the baro/radar altitude traces, apply the reaction time allowance, interpolate the dead-man-curve boundary height where height loss plus recovery altitude equals the starting height at each speed, build the avoid-region map over ...