Page:CAB Accident Report, Eastern Air Lines Flight 21.pdf/22

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the possibility that the instrument was not changed from the setting of 30.03 previously made at Washington. In that event the error would have amounted to approximately 1,200 feet and would probably have resulted in a crash at a much earlier stage of the instrument approach than that at which it actually occurred. Moreover, it is most improbable that some adjustment was not made in this instrument after the Atlanta Airport setting was broadcast to Trip 21 and correctly acknowledged by a member of the crew.

As evidence of a possible missetting it should be noted that the setting of the altimeter by which operations presumably were being conducted as found in the wreckage was 29.92 inches, which was .98 of an inch in error. This setting did not correspond with the barometric pressure at any point en route. Such an erroneous setting at prevailing temperature would have resulted in the altimeter showing an altitude of 883 feet greater than was actually the fact. As previously mentioned, this instrument may not have been set exactly as found in the wreckage, especially since the setting of the other, or route altimeter as found was so manifestly in error as to indicate that the crash had materially altered the setting. Nevertheless, a setting of this altimeter approximately as found could explain fully the conduct of operations preceding the crash, providing the pilots failed to check both instruments for their accuracy, and would also account for Captain Perry's absence of knowledge of the correct altitude, and his failure to realize that he was confronted by an emergency.

As heretofore pointed out, it is not clear from the evidence which member of the crew received the barometric setting from Eastern's radio