Document ID: chunk:federal_register_of_legislation:F2021C01280:reg:500:p1
Version: federal_register_of_legislation:F2021C01280
Segment Type: reg
Provision Reference: reg 500 (pt 1/2)
Character Range: 72292–75364

500           995                  20
1 000         977                  20
1 500         960                  25
2 000         942                  30
3 000         908                  30
4 000         875                  35
6 000         812                  40
8 000         753                  60
10 000        697                  80
12 000        644                  90
14 000        595                  100
16 000        549                  110
18 000        506                  120
20 000        466                  130
22 000        428                  140
25 000        376                  155
30 000        301                  180
35 000        238                  205
40 000        188                  230
45 000        147                  255
50 000        116                  280

       (3)Hysteresis test
(a) The hysteresis test must begin within 15 minutes of the altimeter's initial exposure to the pressure corresponding to the upper limit of the scale error test in subclause (2). While the altimeter is at this pressure, the hysteresis test is to commence.
(b) Pressure must be increased at a rate simulating a descent in altitude at the rate of 5 000 to 20 000 feet per minute until within 3 000 feet of the first test point (50 per cent of maximum altitude).
(c) The test point is then to be approached at a rate of approximately 3 000 feet per minute. The altimeter must be kept at this pressure for at least 5 minutes, but not more than 15 minutes, before the test reading is taken.
(d) After the reading has been taken, the pressure must be increased further, in the same manner as before, until the pressure corresponding to the second test point (40 per cent of maximum altitude) is reached. The altimeter must be kept at this pressure for at least 1 minute, but not more than 10 minutes, before the test reading is taken.
(e) After the reading has been taken, the pressure must be increased further, in the same manner as before, until atmospheric pressure is reached.
(f) The reading of the altimeter at either of the 2 test points must not differ by more than the tolerance specified in Table 2 in subclause 2 (4) from the reading of the altimeter for the corresponding altitude recorded during the scale error test prescribed in subclause (2).

       (4)After effect test
       Within 5 minutes following the completion of the hysteresis test set out in subclause (3), the reading of the altimeter (corrected for any change in atmospheric pressure) must not differ from the original atmospheric pressure reading by more than the tolerance specified in Table 2.

Table 2 Test tolerances

Test                                                 Tolerance (feet)
Case leak test                                       ±100
Hysteresis test:
First test point (50 per cent of maximum altitude)   75
Second test point (40 per cent of maximum altitude)  75
After effect test                                    30

       (5)Friction test
(a) The altimeter is to be subjected to a steady rate of decrease of pressure approximating