S = 101 + 0.0112 * L + 0.0202 * P + 50
Where S = Safe drop height in feet
L = Load size in gallons
P = Peak flow rate in gallons per second.

The additional 50 feet are a safety factor. The formula does not accurately represent constant-flow tanks and single-engine airtankers. The data table uses actual measurements for these airtankers.

Table 1 lists each type of fixed-wing airtanker approved by the Interagency Airtanker Board and the safe drop height for full and partial loads. The safe drop height for trail drops depends on the interval between releases. To determine the safe drop height for trail drops treat the total volume being released as if it were a single release.

Airtankers are listed by the manufacturer of the tank and gating system rather than by the operator of the airtanker. Airtanker numbers are shown to help determine the type of tank on each airtanker.

				Safe drop height (feet above impact)
Airtanker type	Airtanker numbers	Tank volume	Flow setting	Full Load	1/2 Load	1/3 Load	1/4 Load	1/6 Load	1/8 Load	1/16 Load
ARDCO Aero Flite DC-4 ARDCO Aero Flite DC-4	65, 119, 151, 152, 160,161, 166 65, 119, 151, 152, 160,161, 166	2000 2000	High Low	319 231		192 170	192 170		172 161
Aero Union Corp. C-130 Aero Union Corp. C-130 Aero Union Corp. C-130 Aero Union Corp. C-130 Aero Union Corp. C-130 Aero Union Corp. C-130 Aero Union Corp. C-130 Aero Union Corp. C-130	30, 31, 63, 64, 67 30, 31, 63, 64, 67 30, 31, 63, 64, 67 30, 31, 63, 64, 67 30, 31, 63, 64, 67 30, 31, 63, 64, 67 30, 31, 63, 64, 67 30, 31, 63, 64, 67	3000 3000 3000 3000 3000 3000 3000 3000	1/2 1 2 3 4 6 8 9	130 137 145 150 169 185 190 249	130 137 145 150 169 185 190		130 137 145 150 169 185		130 137 145
Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion Aero Union Corp. P3 Orion	00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21 00, 22, 23, 25, 26, 27, 21	3000 3000 3000 3000 3000 3000 3000 3000	1/2 1 2 3 4 6 8 Max	140 149 166 175 204 223 253 310	140 149 166 173 200 215 242 244	140 149 166 173 194 204 196		140 149 166 166 192
Aero Union Corp. SP2H Aero Union Corp. SP2H Aero Union Corp. SP2H Aero Union Corp. SP2H Aero Union Corp. SP2H Aero Union Corp. SP2H Aero Union Corp. SP2H	01, 03, 16, 18 01, 03, 16, 18 01, 03, 16, 18 01, 03, 16, 18 01, 03, 16, 18 01, 03, 16, 18 01, 03, 16, 18 01, 03, 16, 18	2000 2000 2000 2000 2000 2000 2000 2000	1/2 1 2 3 4 5 6 ED	128 135 143 156 169 196 215 234	128 135 143 150 169 173 173 173		128 135 143 150		128 135 143
Aero Union Conventional C-54 - DC-4 Aero Union Conventional C-54 - DC-4	14, 15 14, 15	2000 2000	High Low	260 202	207 180		180 171		169 161
Aero Union Conventional DC-7 Aero Union Conventional DC-7	33, 60, 62, 66 33, 60, 62, 66	3000 3000	High Low	284 219	221 188		189 171		170 163
Hawkins & Powers C-130 Hawkins & Powers C-130	81, 83, 88, 130, 131, 133 81, 83, 88, 130, 131, 133	3000 3000	High Low	287 241	219 196		185 173		168 163
Hawkins & Powers KC-97 Hawkins & Powers KC-97 Hawkins & Powers KC-97	97 97 97	3200 3200 4000 4000	High Low High Low	323 290 348 298	237 219 257 228		196 186 204 190		174 169 178 171	162 160 164 160
Hawkins & Powers SPB4Y2 Hawkins & Powers SPB4Y2 Hawkins & Powers SPB4Y2 Hawkins & Powers SPB4Y2	121, 123, 124, 126, 127 121, 123, 124, 126, 127 121, 123, 124, 126, 127 121, 123, 124, 126, 127	2200 2200 2000 2000	High Low High Low	265 235 254 223	208 193 203 187		180 172 177 169		165 162 164 160
Marsh Turbo Thrush 60/40 Door Marsh Turbo Thrush 60/40 Door Marsh Turbo Thrush 60/40 Door		380 380 380	40% Door 60% Door Both Doors	80 90 100
Minden Air Inc. P2V-7 Minden Air Inc. P2V-7 Minden Air Inc. P2V-7 Minden Air Inc. P2V-7	55, 99 55, 99 55, 99 55, 99	2450 2450 2000 2000	High Low High Low	288 231 283 228	221 170 217 162	199 145 196 139		176 123 175 121
Neptune, Inc. P2V-7 H & P P2V-7 Neptune, Inc. P2V-7 H & P P2V-7	08, 09, 10, 11, 139, 140 08, 09, 10, 11, 139, 140	2450 2450	High Low	288 215	219 183	199 172		175 162
Neptune Inc. P2V-5 Neptune Inc. P2V-5	05, 06, 07 05, 06, 07	2450 2450	High Low	291 214	221 182	201 173		178 163
Pierce Turbo Thrush		450		80
Snow Airtractor 802 Snow Airtractor 802 Snow Airtractor 802 Snow Airtractor 802 Snow Airtractor 802 Snow Airtractor 802	181, 182 181, 182 181, 182 181, 182 181, 182 181, 182	800 800 800 800 800 800	1/2 1 2 3 4 Max	92 102 123 151 179 186	92 102 123 151 179 186		92 102 116 151 144 144
Western Pilot Services Dromader – Melex gate		500		140
Western Pilot Services Dromader – Transland		500		100