Descent Charts
1. This chart is to be used as a starting guide for parachute selection for
low, mid and high power rockets only. See also Note 3.
2. No chart can be 100% effective in all cases and should not be relied on
without actual research.
3. This chart is to be used only with SPECTRAchutesÓ brand parachutes.
It is NOT compatible with other brands of parachutes.
** part number definition: 1st number - base diameter,
2nd number - across the 'chute flat,
3rd number - is over the top of the 'chute.
Descent Chart
Revision 10-2003
|
Density Altitude Equivalent
Sea Level - 0 feet
For an approx. 15-20 FPS descent rate
|
Size of chute in inches (feet)
|
** part
number
|
Minimum weight in ounces
|
Minimum weight in pounds
|
Maximum weight in ounces
|
Maximum weight in pounds
|
12 (1.0)
|
012-019-016
|
6.0
|
0.37
|
8.0
|
0.50
|
18 (1.5)
|
018-028-024
|
13.5
|
0.84
|
18.0
|
1.12
|
24 (2.0)
|
024-038-032
|
23.9
|
1.5
|
31.9
|
2.0
|
30 (2.5)
|
030-048-040
|
37.4
|
2.3
|
49.9
|
3.1
|
36 (3.0)
|
036-057-048
|
54.0
|
3.4
|
71.9
|
4.5
|
42 (3.5)
|
042-066-057
|
73.3
|
4.6
|
97.8
|
6.1
|
48 (4.0)
|
048-075-065
|
95.8
|
6.0
|
128
|
8.0
|
54 (4.5)
|
054-085-073
|
121
|
7.6
|
162
|
10
|
60 (5.0)
|
060-095-082
|
150
|
9.4
|
200
|
12
|
72 (6.0)
|
072-113-097
|
215
|
13
|
287
|
18
|
84 (7.0)
|
084-132-114
|
294
|
18
|
391
|
24
|
96 (8.0)
|
096-151-130
|
383
|
24
|
511
|
32
|
108 (9.0)
|
108-170-146
|
485
|
30
|
647
|
40
|
120 (10)
|
120-188-162
|
599
|
37
|
798
|
50
|
144 (12)
|
144-226-196
|
862
|
54
|
1150
|
72
|
SPECTRAchutesÓ is copyrighted 2000 - 2012 McBride AeroSpace. All rights reserved.
Descent Chart
Revision 10-2003
|
Density Altitude Equivalent
5,000 feet
For an approx. 15-20 FPS descent rate
|
Size of chute in inches (feet)
|
** part
number
|
Minimum weight in ounces
|
Minimum weight in pounds
|
Maximum weight in ounces
|
Maximum weight in pounds
|
12 (1.0)
|
012-019-016
|
5.1
|
0.32
|
6.8
|
0.42
|
18 (1.5)
|
018-028-024
|
11.5
|
0.72
|
15.3
|
0.95
|
24 (2.0)
|
024-038-032
|
20.3
|
1.3
|
27.2
|
1.7
|
30 (2.5)
|
030-048-040
|
31.8
|
2.0
|
42.4
|
2.7
|
36 (3.0)
|
036-057-048
|
45.9
|
2.9
|
61.1
|
3.8
|
42 (3.5)
|
042-066-057
|
62.3
|
3.9
|
83.1
|
5.2
|
48 (4.0)
|
048-075-065
|
81.5
|
5.1
|
109
|
6.8
|
54 (4.5)
|
054-085-073
|
103
|
6.4
|
137
|
8.6
|
60 (5.0)
|
060-095-082
|
127
|
7.9
|
170
|
11
|
72 (6.0)
|
072-113-097
|
183
|
11
|
244
|
15
|
84 (7.0)
|
084-132-114
|
250
|
16
|
333
|
21
|
96 (8.0)
|
096-151-130
|
326
|
20
|
434
|
27
|
108 (9.0)
|
108-170-146
|
412
|
26
|
550
|
34
|
120 (10)
|
120-188-162
|
509
|
32
|
679
|
42
|
144 (12)
|
144-226-196
|
733
|
46
|
977
|
61
|
SPECTRAchutesÓ is copyrighted 2000 - 2012 McBride AeroSpace. All rights reserved.
Descent Chart
Revision 10-2003
|
Density Altitude Equivalent
10,000 feet
For an approx. 15-20 FPS descent rate
|
Size of chute in inches (feet)
|
** part
number
|
Minimum weight in ounces
|
Minimum weight in pounds
|
Maximum weight in ounces
|
Maximum weight in pounds
|
12 (1.0)
|
012-019-016
|
4.2
|
0.26
|
5.6
|
0.35
|
18 (1.5)
|
018-028-024
|
9.4
|
0.59
|
12.6
|
0.79
|
24 (2.0)
|
024-038-032
|
16.7
|
1.0
|
22.4
|
1.4
|
30 (2.5)
|
030-048-040
|
26.2
|
1.6
|
34.9
|
2.2
|
36 (3.0)
|
036-057-048
|
37.8
|
2.4
|
50.3
|
3.1
|
42 (3.5)
|
042-066-057
|
51.3
|
3.2
|
68.5
|
4.3
|
48 (4.0)
|
048-075-065
|
67.1
|
4.2
|
89.4
|
5.6
|
54 (4.5)
|
054-085-073
|
85.0
|
5.3
|
113
|
7.1
|
60 (5.0)
|
060-095-082
|
105
|
6.5
|
140
|
8.7
|
72 (6.0)
|
072-113-097
|
151
|
9.4
|
201
|
13
|
84 (7.0)
|
084-132-114
|
206
|
13
|
274
|
17
|
96 (8.0)
|
096-151-130
|
268
|
17
|
358
|
22
|
108 (9.0)
|
108-170-146
|
339
|
21
|
453
|
28
|
120 (10)
|
120-188-162
|
419
|
26
|
559
|
35
|
144 (12)
|
144-226-196
|
604
|
38
|
805
|
50
|
SPECTRAchutesÓ is copyrighted 2000 - 2012 McBride AeroSpace. All rights reserved.
Here is a download able 1 page version of the Descent Chart in Adobe format.
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Adobe Reader version 4.0 or newer. Download your copy from the
Adobe web site.