diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5c04eb877..baff78c36 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,7 @@ straightforward as possible.
 ### Fixed
 
 - ENH: Parachute trigger doesn't work if "Apogee" is used instead of "apogee" [#489](https://github.com/RocketPy-Team/RocketPy/pull/489)
+- BUG: fin_flutter_analysis doesn't find any fin set [#510](https://github.com/RocketPy-Team/RocketPy/pull/510)
 - FIX: EmptyMotor is breaking the Rocket.draw() method [#516](https://github.com/RocketPy-Team/RocketPy/pull/516)
 
 ## [v1.1.4] - 2023-12-07
diff --git a/rocketpy/utilities.py b/rocketpy/utilities.py
index a1dfadaf5..bcdf2f658 100644
--- a/rocketpy/utilities.py
+++ b/rocketpy/utilities.py
@@ -217,7 +217,7 @@ def fin_flutter_analysis(
         The fin thickness, in meters
     shear_modulus : float
         Shear Modulus of fins' material, must be given in Pascal
-    flight : rocketpy.Flight
+    flight : Flight
         Flight object containing the rocket's flight data
     see_prints : boolean, optional
         True if you want to see the prints, False otherwise.
@@ -229,52 +229,52 @@ def fin_flutter_analysis(
     ------
     None
     """
+    found_fin = False
 
-    # First, we need identify if there is at least a fin set in the rocket
-    for aero_surface in flight.rocket.aerodynamic_surfaces:
+    # First, we need identify if there is at least one fin set in the rocket
+    for aero_surface in flight.rocket.fins:
         if isinstance(aero_surface, TrapezoidalFins):
             # s: surface area; ar: aspect ratio; la: lambda
             root_chord = aero_surface.root_chord
             s = (aero_surface.tip_chord + root_chord) * aero_surface.span / 2
             ar = aero_surface.span * aero_surface.span / s
             la = aero_surface.tip_chord / root_chord
+            if not found_fin:
+                found_fin = True
+            else:
+                warnings.warn("More than one fin set found. The last one will be used.")
+    if not found_fin:
+        raise AttributeError(
+            "There is no TrapezoidalFins in the rocket, can't run Flutter Analysis."
+        )
 
-    # This ensures that a fin set was found in the rocket, if not, break
-    try:
-        s = s
-    except NameError:
-        print("There is no fin set in the rocket, can't run a Flutter Analysis.")
-        return None
-
-    # Calculate the Fin Flutter Mach Number
-    flutter_mach = (
-        (shear_modulus * 2 * (ar + 2) * (fin_thickness / root_chord) ** 3)
-        / (1.337 * (ar**3) * (la + 1) * flight.pressure)
-    ) ** 0.5
-
+    # Calculate variables
+    flutter_mach = _flutter_mach_number(
+        fin_thickness, shear_modulus, flight, root_chord, ar, la
+    )
     safety_factor = _flutter_safety_factor(flight, flutter_mach)
 
-    # Prints everything
+    # Prints and plots
     if see_prints:
         _flutter_prints(
-            fin_thickness,
-            shear_modulus,
-            s,
-            ar,
-            la,
-            flutter_mach,
-            safety_factor,
-            flight,
+            fin_thickness, shear_modulus, s, ar, la, flutter_mach, safety_factor, flight
         )
-
-    # Plots everything
     if see_graphs:
         _flutter_plots(flight, flutter_mach, safety_factor)
-        return None
     else:
         return flutter_mach, safety_factor
 
 
+def _flutter_mach_number(fin_thickness, shear_modulus, flight, root_chord, ar, la):
+    flutter_mach = (
+        (shear_modulus * 2 * (ar + 2) * (fin_thickness / root_chord) ** 3)
+        / (1.337 * (ar**3) * (la + 1) * flight.pressure)
+    ) ** 0.5
+    flutter_mach.set_title("Fin Flutter Mach Number")
+    flutter_mach.set_outputs("Mach")
+    return flutter_mach
+
+
 def _flutter_safety_factor(flight, flutter_mach):
     """Calculates the safety factor for the fin flutter analysis.
 
@@ -291,25 +291,9 @@ def _flutter_safety_factor(flight, flutter_mach):
     rocketpy.Function
         The safety factor for the fin flutter analysis.
     """
-    safety_factor = [[t, 0] for t in flutter_mach[:, 0]]
-    for i in range(len(flutter_mach)):
-        try:
-            safety_factor[i][1] = flutter_mach[i][1] / flight.mach_number[i][1]
-        except ZeroDivisionError:
-            safety_factor[i][1] = np.nan
-
-    # Function needs to remove NaN and Inf values from the source
-    safety_factor = np.array(safety_factor)
-    safety_factor = safety_factor[~np.isnan(safety_factor).any(axis=1)]
-    safety_factor = safety_factor[~np.isinf(safety_factor).any(axis=1)]
-
-    safety_factor = Function(
-        source=safety_factor,
-        inputs="Time (s)",
-        outputs="Fin Flutter Safety Factor",
-        interpolation="linear",
-    )
-
+    safety_factor = flutter_mach / flight.mach_number
+    safety_factor.set_title("Fin Flutter Safety Factor")
+    safety_factor.set_outputs("Safety Factor")
     return safety_factor
 
 
@@ -331,7 +315,8 @@ def _flutter_plots(flight, flutter_mach, safety_factor):
     -------
     None
     """
-    fig = plt.figure(figsize=(6, 6))
+    # TODO: move to rocketpy.plots submodule
+    _ = plt.figure(figsize=(6, 6))
     ax1 = plt.subplot(211)
     ax1.plot(
         flutter_mach[:, 0],
@@ -362,8 +347,6 @@ def _flutter_plots(flight, flutter_mach, safety_factor):
     plt.subplots_adjust(hspace=0.5)
     plt.show()
 
-    return None
-
 
 def _flutter_prints(
     fin_thickness,
@@ -404,6 +387,7 @@ def _flutter_prints(
     -------
     None
     """
+    # TODO: move to rocketpy.prints submodule
     time_index = np.argmin(flutter_mach[:, 1])
     time_min_mach = flutter_mach[time_index, 0]
     min_mach = flutter_mach[time_index, 1]
@@ -427,8 +411,6 @@ def _flutter_prints(
     print(f"Minimum Safety Factor: {min_sf:.3f} at {time_min_sf:.2f} s")
     print(f"Altitude of minimum Safety Factor: {altitude_min_sf:.3f} m (AGL)\n")
 
-    return None
-
 
 def create_dispersion_dictionary(filename):
     """Creates a dictionary with the rocket data provided by a .csv file.
diff --git a/tests/fixtures/utilities/flutter_mach.txt b/tests/fixtures/utilities/flutter_mach.txt
new file mode 100644
index 000000000..675072670
--- /dev/null
+++ b/tests/fixtures/utilities/flutter_mach.txt
@@ -0,0 +1,544 @@
+0.00000,1.00482
+0.00141,1.00482
+0.00282,1.00482
+0.00564,1.00482
+0.00846,1.00482
+0.01128,1.00482
+0.03947,1.00482
+0.04086,1.00482
+0.04224,1.00482
+0.04502,1.00482
+0.04779,1.00482
+0.05057,1.00482
+0.05154,1.00482
+0.05250,1.00482
+0.05443,1.00482
+0.05637,1.00482
+0.05830,1.00482
+0.06067,1.00482
+0.06304,1.00482
+0.06541,1.00482
+0.08910,1.00482
+0.09281,1.00482
+0.09576,1.00482
+0.09871,1.00482
+0.10100,1.00482
+0.10329,1.00482
+0.10558,1.00482
+0.11016,1.00482
+0.11474,1.00482
+0.11932,1.00482
+0.13124,1.00483
+0.14316,1.00483
+0.14995,1.00483
+0.15419,1.00484
+0.15844,1.00484
+0.16268,1.00484
+0.17117,1.00484
+0.17966,1.00485
+0.18815,1.00485
+0.19448,1.00486
+0.20082,1.00486
+0.20568,1.00487
+0.21055,1.00487
+0.21542,1.00487
+0.22515,1.00488
+0.23488,1.00489
+0.24461,1.00490
+0.25434,1.00491
+0.35166,1.00503
+0.36325,1.00505
+0.36690,1.00505
+0.37055,1.00506
+0.37785,1.00507
+0.38516,1.00508
+0.39246,1.00510
+0.43464,1.00518
+0.47682,1.00526
+0.51901,1.00536
+0.56119,1.00547
+0.60478,1.00559
+0.64836,1.00573
+0.69195,1.00587
+0.73553,1.00603
+0.79677,1.00627
+0.85800,1.00653
+0.91924,1.00682
+0.98047,1.00713
+1.04171,1.00746
+1.05229,1.00752
+1.06287,1.00758
+1.07345,1.00764
+1.08402,1.00770
+1.12937,1.00797
+1.17471,1.00826
+1.22005,1.00855
+1.26539,1.00886
+1.27509,1.00893
+1.28478,1.00900
+1.29448,1.00907
+1.32865,1.00932
+1.36282,1.00957
+1.39699,1.00984
+1.43116,1.01011
+1.46533,1.01038
+1.49950,1.01067
+1.53368,1.01096
+1.56785,1.01126
+1.60202,1.01157
+1.63619,1.01188
+1.67927,1.01229
+1.72235,1.01270
+1.76544,1.01313
+1.80852,1.01357
+1.85160,1.01403
+1.89468,1.01449
+1.93777,1.01496
+1.98085,1.01545
+2.02393,1.01595
+2.06115,1.01639
+2.08798,1.01671
+2.11482,1.01703
+2.14165,1.01736
+2.16848,1.01770
+2.19531,1.01804
+2.22783,1.01845
+2.26036,1.01887
+2.29288,1.01930
+2.31902,1.01965
+2.34517,1.02000
+2.37131,1.02036
+2.39746,1.02072
+2.42360,1.02109
+2.44975,1.02146
+2.47589,1.02183
+2.50204,1.02221
+2.52818,1.02259
+2.55433,1.02297
+2.58047,1.02336
+2.60661,1.02375
+2.63276,1.02415
+2.65890,1.02455
+2.68505,1.02495
+2.71119,1.02536
+2.73734,1.02577
+2.76348,1.02619
+2.79375,1.02667
+2.82401,1.02716
+2.85427,1.02766
+2.88454,1.02816
+2.90971,1.02858
+2.93489,1.02901
+2.96007,1.02943
+2.98525,1.02987
+2.98903,1.02993
+2.99282,1.03000
+2.99660,1.03006
+3.00038,1.03013
+3.00795,1.03026
+3.01552,1.03039
+3.02308,1.03052
+3.03065,1.03065
+3.03980,1.03081
+3.04895,1.03097
+3.05810,1.03113
+3.06725,1.03129
+3.08355,1.03158
+3.09985,1.03187
+3.11615,1.03216
+3.13245,1.03245
+3.14875,1.03274
+3.16969,1.03312
+3.19063,1.03350
+3.21157,1.03388
+3.23251,1.03425
+3.25345,1.03464
+3.28027,1.03512
+3.30176,1.03552
+3.30506,1.03558
+3.30836,1.03564
+3.31166,1.03570
+3.31496,1.03576
+3.31825,1.03582
+3.32485,1.03594
+3.33145,1.03606
+3.33804,1.03618
+3.34464,1.03630
+3.35947,1.03657
+3.37429,1.03684
+3.38912,1.03712
+3.40394,1.03739
+3.41877,1.03766
+3.43360,1.03793
+3.44842,1.03820
+3.46573,1.03852
+3.48304,1.03884
+3.50035,1.03916
+3.51766,1.03947
+3.53497,1.03979
+3.56092,1.04027
+3.58688,1.04074
+3.61283,1.04122
+3.63879,1.04170
+3.66474,1.04217
+3.68617,1.04257
+3.70759,1.04296
+3.72902,1.04335
+3.75044,1.04374
+3.77187,1.04414
+3.79928,1.04464
+3.82669,1.04514
+3.85410,1.04564
+3.88151,1.04614
+3.90892,1.04664
+3.93633,1.04714
+3.95590,1.04749
+3.97548,1.04785
+3.99505,1.04820
+4.01463,1.04855
+4.03420,1.04891
+4.06760,1.04951
+4.10099,1.05011
+4.12663,1.05057
+4.15226,1.05104
+4.17789,1.05150
+4.20352,1.05196
+4.22916,1.05241
+4.25840,1.05294
+4.28764,1.05346
+4.31688,1.05398
+4.34613,1.05450
+4.37537,1.05502
+4.40461,1.05554
+4.43385,1.05606
+4.46310,1.05657
+4.49234,1.05709
+4.52158,1.05761
+4.55082,1.05812
+4.58451,1.05871
+4.61820,1.05930
+4.65189,1.05989
+4.68558,1.06048
+4.71927,1.06107
+4.75296,1.06166
+4.78665,1.06225
+4.82034,1.06283
+4.85403,1.06341
+4.88772,1.06400
+4.92141,1.06458
+4.96628,1.06535
+5.01115,1.06612
+5.04557,1.06672
+5.07999,1.06731
+5.11442,1.06789
+5.14884,1.06848
+5.18327,1.06907
+5.21769,1.06965
+5.26816,1.07051
+5.31863,1.07137
+5.35914,1.07205
+5.39965,1.07273
+5.44016,1.07341
+5.48067,1.07409
+5.52118,1.07477
+5.56168,1.07545
+5.61536,1.07634
+5.65989,1.07708
+5.70441,1.07782
+5.74893,1.07856
+5.79345,1.07930
+5.83798,1.08003
+5.88250,1.08076
+5.92702,1.08149
+5.97154,1.08222
+6.01607,1.08295
+6.06059,1.08367
+6.10511,1.08439
+6.14964,1.08511
+6.19416,1.08583
+6.23868,1.08655
+6.28320,1.08727
+6.32773,1.08798
+6.37225,1.08870
+6.42126,1.08948
+6.47027,1.09026
+6.51928,1.09104
+6.56829,1.09182
+6.61730,1.09259
+6.66631,1.09336
+6.72280,1.09425
+6.77929,1.09514
+6.83577,1.09602
+6.89226,1.09690
+6.94875,1.09778
+7.00523,1.09865
+7.07604,1.09975
+7.14685,1.10084
+7.21766,1.10192
+7.28846,1.10300
+7.35927,1.10408
+7.43008,1.10515
+7.50088,1.10622
+7.57169,1.10728
+7.64250,1.10834
+7.74261,1.10984
+7.81742,1.11094
+7.89222,1.11205
+7.96702,1.11315
+8.04182,1.11425
+8.11662,1.11534
+8.19143,1.11643
+8.26623,1.11751
+8.34103,1.11859
+8.41583,1.11966
+8.50693,1.12096
+8.59802,1.12226
+8.68911,1.12354
+8.78020,1.12483
+8.87130,1.12610
+8.97337,1.12752
+9.07544,1.12893
+9.17751,1.13034
+9.27958,1.13174
+9.39730,1.13334
+9.51501,1.13492
+9.63272,1.13650
+9.75043,1.13807
+9.88568,1.13986
+10.02093,1.14163
+10.15618,1.14339
+10.29143,1.14513
+10.42668,1.14686
+10.56193,1.14858
+10.69717,1.15028
+10.85200,1.15221
+11.00683,1.15413
+11.16166,1.15602
+11.31649,1.15789
+11.45719,1.15958
+11.59788,1.16125
+11.73857,1.16291
+11.87927,1.16455
+12.03717,1.16638
+12.19507,1.16818
+12.35298,1.16996
+12.51088,1.17173
+12.53835,1.17204
+12.56582,1.17234
+12.59329,1.17264
+12.64822,1.17325
+12.70316,1.17385
+12.75810,1.17446
+12.91464,1.17616
+13.07118,1.17784
+13.22773,1.17950
+13.38427,1.18115
+13.54081,1.18277
+13.69736,1.18438
+13.85390,1.18597
+14.01044,1.18753
+14.16699,1.18908
+14.32353,1.19061
+14.49866,1.19230
+14.67379,1.19396
+14.84892,1.19561
+15.02405,1.19722
+15.19258,1.19876
+15.36112,1.20027
+15.52965,1.20175
+15.69818,1.20322
+15.89510,1.20491
+16.09201,1.20656
+16.28892,1.20818
+16.48584,1.20978
+16.71249,1.21157
+16.88934,1.21295
+17.06620,1.21430
+17.24305,1.21562
+17.41990,1.21692
+17.66279,1.21866
+17.84823,1.21996
+18.03368,1.22124
+18.21912,1.22248
+18.40457,1.22370
+18.63691,1.22519
+18.81772,1.22632
+18.99853,1.22742
+19.17934,1.22849
+19.36014,1.22954
+19.57740,1.23077
+19.79465,1.23196
+20.01191,1.23311
+20.22916,1.23422
+20.44642,1.23530
+20.66367,1.23634
+20.88093,1.23734
+21.09818,1.23830
+21.31544,1.23922
+21.53269,1.24011
+21.79548,1.24113
+22.05827,1.24209
+22.32106,1.24300
+22.58385,1.24385
+22.84664,1.24465
+23.17773,1.24558
+23.50882,1.24641
+23.83991,1.24716
+24.17100,1.24782
+24.44426,1.24830
+24.71751,1.24872
+24.99077,1.24908
+25.26402,1.24937
+25.48785,1.24957
+25.71168,1.24973
+25.93551,1.24985
+26.15934,1.24993
+26.38317,1.24997
+26.48571,1.24997
+26.49203,1.24997
+26.49834,1.24997
+26.51097,1.24997
+26.52359,1.24997
+26.53622,1.24997
+26.66249,1.24996
+26.78876,1.24993
+26.91502,1.24990
+27.04129,1.24985
+27.22094,1.24975
+27.40059,1.24963
+27.58024,1.24949
+27.75989,1.24932
+27.93954,1.24913
+27.98571,1.24907
+28.00326,1.24905
+28.02081,1.24903
+28.05590,1.24899
+28.09099,1.24895
+28.12608,1.24890
+28.31218,1.24868
+28.49828,1.24845
+28.68439,1.24822
+28.87049,1.24799
+29.15129,1.24763
+29.43209,1.24726
+29.71289,1.24688
+29.99369,1.24650
+30.27450,1.24610
+30.75950,1.24541
+31.24450,1.24469
+31.72951,1.24396
+32.21451,1.24321
+32.69952,1.24244
+33.18452,1.24166
+33.82542,1.24062
+34.46632,1.23957
+35.10722,1.23851
+35.74812,1.23744
+36.38902,1.23637
+37.10961,1.23516
+37.83020,1.23395
+38.55080,1.23274
+39.27139,1.23152
+40.20139,1.22996
+41.13139,1.22841
+42.06139,1.22685
+42.99139,1.22530
+44.27285,1.22317
+45.55431,1.22105
+46.83578,1.21894
+48.11724,1.21684
+49.39870,1.21475
+50.35181,1.21319
+51.30492,1.21165
+52.25803,1.21010
+53.21115,1.20856
+54.20806,1.20696
+55.20498,1.20536
+56.20190,1.20377
+58.19080,1.20060
+60.17970,1.19746
+62.16861,1.19433
+64.15407,1.19123
+66.13953,1.18815
+68.12499,1.18509
+70.10805,1.18204
+72.09112,1.17902
+74.07418,1.17602
+76.05617,1.17303
+78.03817,1.17007
+80.02016,1.16712
+90.39343,1.15197
+92.98675,1.14826
+95.58007,1.14457
+98.17339,1.14092
+103.36002,1.13368
+108.54666,1.12656
+113.73329,1.11954
+118.91993,1.11262
+130.27132,1.09784
+141.62271,1.08351
+152.97409,1.06961
+164.32548,1.05614
+164.55238,1.05587
+164.67454,1.05573
+164.79671,1.05559
+166.05238,1.05412
+166.05481,1.05412
+166.05723,1.05412
+166.06209,1.05411
+166.06694,1.05411
+166.07179,1.05410
+166.09452,1.05408
+166.11724,1.05405
+166.13997,1.05403
+166.16269,1.05401
+166.19698,1.05398
+166.23126,1.05395
+166.26554,1.05393
+166.29982,1.05390
+166.33411,1.05388
+166.39386,1.05384
+166.45362,1.05380
+166.51338,1.05376
+166.57313,1.05373
+166.63289,1.05370
+166.69265,1.05367
+166.78997,1.05362
+166.88728,1.05357
+166.98460,1.05353
+167.08192,1.05349
+167.17924,1.05345
+167.27656,1.05341
+167.43378,1.05334
+167.59101,1.05328
+167.74824,1.05322
+167.90546,1.05316
+168.06269,1.05310
+168.28621,1.05302
+168.50974,1.05293
+168.73327,1.05285
+168.95679,1.05277
+169.18032,1.05269
+169.47144,1.05258
+169.76256,1.05247
+170.05368,1.05237
+170.34480,1.05226
+170.65364,1.05215
+170.96247,1.05203
+171.27130,1.05192
+171.58063,1.05181
+171.88996,1.05170
+172.19930,1.05158
+172.50867,1.05147
+174.11482,1.05088
+175.72096,1.05030
+177.32711,1.04971
+182.05305,1.04800
+186.77899,1.04629
+191.50492,1.04458
+206.83749,1.03910
+222.17005,1.03369
+237.50262,1.02835
+261.57709,1.02008
+285.65156,1.01198
+307.29931,1.00482
diff --git a/tests/fixtures/utilities/flutter_safety_factor.txt b/tests/fixtures/utilities/flutter_safety_factor.txt
new file mode 100644
index 000000000..d16f406a6
--- /dev/null
+++ b/tests/fixtures/utilities/flutter_safety_factor.txt
@@ -0,0 +1,544 @@
+0.00000,64.78797
+0.00141,64.78797
+0.00282,64.78797
+0.00564,64.78797
+0.00846,64.78797
+0.01128,64.78797
+0.03947,64.78797
+0.04086,64.78797
+0.04224,64.78797
+0.04502,64.78797
+0.04779,64.78797
+0.05057,64.78797
+0.05154,64.78797
+0.05250,64.78797
+0.05443,64.78797
+0.05637,64.78797
+0.05830,64.78870
+0.06067,64.79250
+0.06304,64.79970
+0.06541,64.80872
+0.08910,64.07620
+0.09281,63.57463
+0.09576,63.02247
+0.09871,62.29744
+0.10100,61.61289
+0.10329,60.84649
+0.10558,60.01939
+0.11016,58.21319
+0.11474,56.25412
+0.11932,54.19828
+0.13124,48.72230
+0.14316,43.50321
+0.14995,40.76230
+0.15419,39.16578
+0.15844,37.68120
+0.16268,36.30211
+0.17117,33.83169
+0.17966,31.69778
+0.18815,29.84870
+0.19448,28.62739
+0.20082,27.52171
+0.20568,26.73258
+0.21055,25.98188
+0.21542,25.26726
+0.22515,23.93750
+0.23488,22.72719
+0.24461,21.62231
+0.25434,20.61072
+0.35166,13.86414
+0.36325,13.32773
+0.36690,13.16685
+0.37055,13.00954
+0.37785,12.70534
+0.38516,12.41405
+0.39246,12.13490
+0.43464,10.72612
+0.47682,9.59273
+0.51901,8.66353
+0.56119,7.89146
+0.60478,7.22183
+0.64836,6.65328
+0.69195,6.16468
+0.73553,5.74038
+0.79677,5.23076
+0.85800,4.80096
+0.91924,4.43372
+0.98047,4.11643
+1.04171,3.84018
+1.05229,3.79617
+1.06287,3.75316
+1.07345,3.71112
+1.08402,3.67003
+1.12937,3.50382
+1.17471,3.35218
+1.22005,3.21328
+1.26539,3.08560
+1.27509,3.05962
+1.28478,3.03409
+1.29448,3.00899
+1.32865,2.92379
+1.36282,2.84337
+1.39699,2.76734
+1.43116,2.69535
+1.46533,2.62708
+1.49950,2.56226
+1.53368,2.50069
+1.56785,2.44224
+1.60202,2.38667
+1.63619,2.33379
+1.67927,2.27065
+1.72235,2.21115
+1.76544,2.15501
+1.80852,2.10194
+1.85160,2.05172
+1.89468,2.00413
+1.93777,1.95896
+1.98085,1.91605
+2.02393,1.87524
+2.06115,1.84161
+2.08798,1.81827
+2.11482,1.79563
+2.14165,1.77368
+2.16848,1.75238
+2.19531,1.73170
+2.22783,1.70745
+2.26036,1.68404
+2.29288,1.66143
+2.31902,1.64381
+2.34517,1.62666
+2.37131,1.60997
+2.39746,1.59372
+2.42360,1.57790
+2.44975,1.56248
+2.47589,1.54747
+2.50204,1.53283
+2.52818,1.51856
+2.55433,1.50461
+2.58047,1.49097
+2.60661,1.47763
+2.63276,1.46459
+2.65890,1.45184
+2.68505,1.43937
+2.71119,1.42715
+2.73734,1.41520
+2.76348,1.40350
+2.79375,1.39025
+2.82401,1.37733
+2.85427,1.36470
+2.88454,1.35238
+2.90971,1.34235
+2.93489,1.33256
+2.96007,1.32302
+2.98525,1.31373
+2.98903,1.31235
+2.99282,1.31098
+2.99660,1.30962
+3.00038,1.30826
+3.00795,1.30559
+3.01552,1.30299
+3.02308,1.30046
+3.03065,1.29800
+3.03980,1.29513
+3.04895,1.29236
+3.05810,1.28969
+3.06725,1.28713
+3.08355,1.28281
+3.09985,1.27880
+3.11615,1.27510
+3.13245,1.27170
+3.14875,1.26860
+3.16969,1.26505
+3.19063,1.26197
+3.21157,1.25936
+3.23251,1.25721
+3.25345,1.25551
+3.28027,1.25400
+3.30176,1.25330
+3.30506,1.25323
+3.30836,1.25316
+3.31166,1.25310
+3.31496,1.25305
+3.31825,1.25300
+3.32485,1.25291
+3.33145,1.25285
+3.33804,1.25281
+3.34464,1.25279
+3.35947,1.25282
+3.37429,1.25296
+3.38912,1.25321
+3.40394,1.25355
+3.41877,1.25395
+3.43360,1.25440
+3.44842,1.25489
+3.46573,1.25551
+3.48304,1.25618
+3.50035,1.25691
+3.51766,1.25770
+3.53497,1.25854
+3.56092,1.25991
+3.58688,1.26140
+3.61283,1.26301
+3.63879,1.26476
+3.66474,1.26662
+3.68617,1.26826
+3.70759,1.26999
+3.72902,1.27180
+3.75044,1.27370
+3.77187,1.27568
+3.79928,1.27835
+3.82669,1.28117
+3.85410,1.28413
+3.88151,1.28724
+3.90892,1.29047
+3.93633,1.29377
+3.95590,1.29612
+3.97548,1.29847
+3.99505,1.30081
+4.01463,1.30317
+4.03420,1.30552
+4.06760,1.30954
+4.10099,1.31356
+4.12663,1.31665
+4.15226,1.31974
+4.17789,1.32284
+4.20352,1.32595
+4.22916,1.32906
+4.25840,1.33261
+4.28764,1.33617
+4.31688,1.33974
+4.34613,1.34331
+4.37537,1.34690
+4.40461,1.35048
+4.43385,1.35408
+4.46310,1.35768
+4.49234,1.36129
+4.52158,1.36490
+4.55082,1.36853
+4.58451,1.37271
+4.61820,1.37690
+4.65189,1.38110
+4.68558,1.38531
+4.71927,1.38953
+4.75296,1.39376
+4.78665,1.39800
+4.82034,1.40224
+4.85403,1.40650
+4.88772,1.41077
+4.92141,1.41505
+4.96628,1.42076
+5.01115,1.42649
+5.04557,1.43089
+5.07999,1.43531
+5.11442,1.43974
+5.14884,1.44418
+5.18327,1.44862
+5.21769,1.45308
+5.26816,1.45964
+5.31863,1.46622
+5.35914,1.47152
+5.39965,1.47683
+5.44016,1.48216
+5.48067,1.48751
+5.52118,1.49286
+5.56168,1.49824
+5.61536,1.50538
+5.65989,1.51133
+5.70441,1.51730
+5.74893,1.52328
+5.79345,1.52929
+5.83798,1.53531
+5.88250,1.54135
+5.92702,1.54742
+5.97154,1.55349
+6.01607,1.55959
+6.06059,1.56570
+6.10511,1.57183
+6.14964,1.57798
+6.19416,1.58414
+6.23868,1.59032
+6.28320,1.59652
+6.32773,1.60274
+6.37225,1.60897
+6.42126,1.61586
+6.47027,1.62276
+6.51928,1.62969
+6.56829,1.63664
+6.61730,1.64362
+6.66631,1.65061
+6.72280,1.65871
+6.77929,1.66683
+6.83577,1.67499
+6.89226,1.68318
+6.94875,1.69140
+7.00523,1.69965
+7.07604,1.71005
+7.14685,1.72049
+7.21766,1.73099
+7.28846,1.74155
+7.35927,1.75215
+7.43008,1.76282
+7.50088,1.77354
+7.57169,1.78432
+7.64250,1.79516
+7.74261,1.81058
+7.81742,1.82218
+7.89222,1.83385
+7.96702,1.84558
+8.04182,1.85739
+8.11662,1.86927
+8.19143,1.88122
+8.26623,1.89324
+8.34103,1.90534
+8.41583,1.91751
+8.50693,1.93243
+8.59802,1.94747
+8.68911,1.96263
+8.78020,1.97790
+8.87130,1.99329
+8.97337,2.01069
+9.07544,2.02824
+9.17751,2.04595
+9.27958,2.06382
+9.39730,2.08464
+9.51501,2.10568
+9.63272,2.12695
+9.75043,2.14846
+9.88568,2.17347
+10.02093,2.19881
+10.15618,2.22448
+10.29143,2.25050
+10.42668,2.27687
+10.56193,2.30361
+10.69717,2.33071
+10.85200,2.36221
+11.00683,2.39423
+11.16166,2.42677
+11.31649,2.45986
+11.45719,2.49042
+11.59788,2.52145
+11.73857,2.55297
+11.87927,2.58500
+12.03717,2.62156
+12.19507,2.65880
+12.35298,2.69674
+12.51088,2.73539
+12.53835,2.74219
+12.56582,2.74901
+12.59329,2.75586
+12.64822,2.76961
+12.70316,2.78346
+12.75810,2.79741
+12.91464,2.83767
+13.07118,2.87872
+13.22773,2.92059
+13.38427,2.96331
+13.54081,3.00690
+13.69736,3.05141
+13.85390,3.09686
+14.01044,3.14328
+14.16699,3.19071
+14.32353,3.23918
+14.49866,3.29470
+14.67379,3.35163
+14.84892,3.41003
+15.02405,3.46996
+15.19258,3.52914
+15.36112,3.58987
+15.52965,3.65221
+15.69818,3.71622
+15.89510,3.79324
+16.09201,3.87276
+16.28892,3.95494
+16.48584,4.03989
+16.71249,4.14133
+16.88934,4.22333
+17.06620,4.30797
+17.24305,4.39539
+17.41990,4.48573
+17.66279,4.61484
+17.84823,4.71757
+18.03368,4.82413
+18.21912,4.93474
+18.40457,5.04964
+18.63691,5.20002
+18.81772,5.32232
+18.99853,5.44954
+19.17934,5.58197
+19.36014,5.71993
+19.57740,5.89350
+19.79465,6.07620
+20.01191,6.26874
+20.22916,6.47189
+20.44642,6.68648
+20.66367,6.91345
+20.88093,7.15380
+21.09818,7.40864
+21.31544,7.67916
+21.53269,7.96667
+21.79548,8.33915
+22.05827,8.74124
+22.32106,9.17584
+22.58385,9.64600
+22.84664,10.15485
+23.17773,10.85571
+23.50882,11.62791
+23.83991,12.47426
+24.17100,13.39282
+24.44426,14.19841
+24.71751,15.03405
+24.99077,15.87894
+25.26402,16.70184
+25.48785,17.33015
+25.71168,17.88741
+25.93551,18.34360
+26.15934,18.67019
+26.38317,18.84449
+26.48571,18.86954
+26.49203,18.86993
+26.49834,18.87019
+26.51097,18.87030
+26.52359,18.86989
+26.53622,18.86894
+26.66249,18.83017
+26.78876,18.73915
+26.91502,18.59816
+27.04129,18.41055
+27.22094,18.07178
+27.40059,17.66160
+27.58024,17.19538
+27.75989,16.68831
+27.93954,16.15447
+27.98571,16.01449
+28.00326,16.08442
+28.02081,16.15388
+28.05590,16.29229
+28.09099,16.42880
+28.12608,16.56338
+28.31218,17.24394
+28.49828,17.86823
+28.68439,18.43516
+28.87049,18.94468
+29.15129,19.60736
+29.43209,20.14822
+29.71289,20.57722
+29.99369,20.90697
+30.27450,21.15100
+30.75950,21.41023
+31.24450,21.51849
+31.72951,21.52921
+32.21451,21.48144
+32.69952,21.40267
+33.18452,21.31111
+33.82542,21.18884
+34.46632,21.07718
+35.10722,20.98154
+35.74812,20.90286
+36.38902,20.83991
+37.10961,20.78525
+37.83020,20.74438
+38.55080,20.71422
+39.27139,20.69224
+40.20139,20.67270
+41.13139,20.65995
+42.06139,20.65178
+42.99139,20.64664
+44.27285,20.64247
+45.55431,20.64042
+46.83578,20.63965
+48.11724,20.63915
+49.39870,20.63880
+50.35181,20.63880
+51.30492,20.63883
+52.25803,20.63886
+53.21115,20.63892
+54.20806,20.63901
+55.20498,20.63910
+56.20190,20.63919
+58.19080,20.63938
+60.17970,20.63958
+62.16861,20.63977
+64.15407,20.63996
+66.13953,20.64015
+68.12499,20.64033
+70.10805,20.64052
+72.09112,20.64070
+74.07418,20.64089
+76.05617,20.64107
+78.03817,20.64124
+80.02016,20.64142
+90.39343,20.64228
+92.98675,20.64249
+95.58007,20.64275
+98.17339,20.64303
+103.36002,20.64346
+108.54666,20.64383
+113.73329,20.64421
+118.91993,20.64460
+130.27132,20.64544
+141.62271,20.64624
+152.97409,20.64699
+164.32548,20.64772
+164.55238,20.64773
+164.67454,20.64774
+164.79671,20.64775
+166.05238,20.64783
+166.05481,20.77952
+166.05723,20.91102
+166.06209,21.17535
+166.06694,21.43890
+166.07179,21.70167
+166.09452,22.92118
+166.11724,24.12309
+166.13997,25.30649
+166.16269,26.47073
+166.19698,28.19017
+166.23126,29.86309
+166.26554,31.48771
+166.29982,33.06332
+166.33411,34.58900
+166.39386,37.12730
+166.45362,39.50943
+166.51338,41.73827
+166.57313,43.81483
+166.63289,45.74249
+166.69265,47.52632
+166.78997,50.13799
+166.88728,52.41218
+166.98460,54.38019
+167.08192,56.07366
+167.17924,57.52416
+167.27656,58.76154
+167.43378,60.37953
+167.59101,61.61653
+167.74824,62.55565
+167.90546,63.26560
+168.06269,63.80099
+168.28621,64.34231
+168.50974,64.70115
+168.73327,64.93912
+168.95679,65.09707
+169.18032,65.20148
+169.47144,65.28605
+169.76256,65.33552
+170.05368,65.36491
+170.34480,65.38195
+170.65364,65.39233
+170.96247,65.39784
+171.27130,65.40086
+171.58063,65.40263
+171.88996,65.40368
+172.19930,65.40428
+172.50867,65.40463
+174.11482,65.40537
+175.72096,65.40528
+177.32711,65.40516
+182.05305,65.40514
+186.77899,65.40517
+191.50492,65.40520
+206.83749,65.40529
+222.17005,65.40538
+237.50262,65.40547
+261.57709,65.40563
+285.65156,65.40568
+307.29931,65.40589
diff --git a/tests/unit/test_utilities.py b/tests/unit/test_utilities.py
index aeb374db6..68dbc3d7f 100644
--- a/tests/unit/test_utilities.py
+++ b/tests/unit/test_utilities.py
@@ -3,7 +3,7 @@
 import numpy as np
 import pytest
 
-from rocketpy import utilities
+from rocketpy import Function, utilities
 
 
 @pytest.mark.parametrize(
@@ -132,35 +132,77 @@ def test_liftoff_by_mass(mock_show, flight):
     assert f.plot() == None
 
 
-@pytest.mark.skip(reason="legacy tests")
-@patch("matplotlib.pyplot.show")
-def test_fin_flutter_analysis(mock_show, flight):
+def test_fin_flutter_analysis(flight_calisto_custom_wind):
     """Tests the fin_flutter_analysis function. It tests the both options of
     the see_graphs parameter.
     Parameters
     ----------
-    flight : rocketpy.Flight
+    flight_calisto_custom_wind : Flight
         A Flight object with a rocket with fins. This flight object was created
         in the conftest.py file.
     """
     flutter_mach, safety_factor = utilities.fin_flutter_analysis(
         fin_thickness=2 / 1000,
         shear_modulus=10e9,
-        flight=flight,
+        flight=flight_calisto_custom_wind,
+        see_prints=False,
         see_graphs=False,
     )
+    assert np.isclose(flutter_mach(0), 1.00482, atol=5e-3)
+    assert np.isclose(flutter_mach(10), 1.1413572089696549, atol=5e-3)
+    assert np.isclose(flutter_mach(np.inf), 1.0048188594647927, atol=5e-3)
+    assert np.isclose(safety_factor(0), 64.78797, atol=5e-3)
+    assert np.isclose(safety_factor(10), 2.1948620401502072, atol=5e-3)
+    assert np.isclose(safety_factor(np.inf), 65.40588722032527, atol=5e-3)
 
-    assert abs(flutter_mach(15) - 1.085461074199555) < 1e-3
-    assert abs(safety_factor(15) - 3.364511241274865) < 1e-3
+
+def test_flutter_prints(flight_calisto_custom_wind):
+    """Tests the _flutter_prints function.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : Flight
+        A Flight object with a rocket with fins. This flight object was created
+        in the conftest.py file.
+    """
+    flutter_mach = Function("tests/fixtures/utilities/flutter_mach.txt")
+    safety_factor = Function("tests/fixtures/utilities/flutter_safety_factor.txt")
     assert (
-        utilities.fin_flutter_analysis(
+        utilities._flutter_prints(  # pylint: disable=protected-access
             fin_thickness=2 / 1000,
             shear_modulus=10e9,
-            flight=flight,
-            see_graphs=True,
+            s=0.009899999999999999,
+            ar=1.2222222222222223,
+            la=0.5,
+            flutter_mach=flutter_mach,
+            safety_factor=safety_factor,
+            flight=flight_calisto_custom_wind,
         )
-        == None
-    )
+        is None
+    ), "An error occurred while running the utilities._flutter_prints function."
+
+
+@patch("matplotlib.pyplot.show")
+def test_flutter_plots(mock_show, flight_calisto_custom_wind):
+    """Tests the _flutter_plots function.
+
+    Parameters
+    ----------
+    mock_show : mock
+        Mock of the matplotlib.pyplot.show function. This is here so the plots
+        are not shown during the tests.
+    flight_calisto_custom_wind : Flight
+        A Flight object with a rocket with fins. This flight object was created
+        in the conftest.py file.
+    """
+    flutter_mach = Function("tests/fixtures/utilities/flutter_mach.txt")
+    safety_factor = Function("tests/fixtures/utilities/flutter_safety_factor.txt")
+    assert (
+        utilities._flutter_plots(  # pylint: disable=protected-access
+            flight_calisto_custom_wind, flutter_mach, safety_factor
+        )
+        is None
+    ), "An error occurred while running the utilities._flutter_plots function."
 
 
 def test_get_instance_attributes(flight_calisto_robust):