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1811D INSTRUCTION MANUAL
56-101-00164 Rev. F
SECTION 3
Apr / 19 / 13
Page 22 of 38
10. MACHMETER TEST
A. Test Procedure
(1) Set an altitude (in feet) as referenced in the following table. Set the corresponding
airspeed (in knots). Verify that the MACH value obtained is the same as listed in
the table for the settings. (For example, an altitude set to
10k
with airspeed of
277
kts
would give a MACH reading of .50.)
MACH NUMBER
.50 .60 .70 .75 .80 .82 .85 .90
Altitude
(In feet)
Airspeed
(In kts)
277 334 391 420 449 --- --- --- 10k
247 298 350 376 403 414 429 --- 15k
228 275 324 348 373 383 398 424 20k
205 248 292 315 338 347 361 384 25k
188 228 269 289 311 319 332 354 29k
172 207 246 265 285 292 304 324 33k
157 190 224 242 260 267 278 297 37k
142 173 204 220 237 243 253 277 41k
--- 157 186 201 216 222 231 246 45k
--- 143 169 183 196 202 210 225 49k
--- --- 161 174 187 193 201 214 51k
Airspeed vs. MACH Number
TABLE 1