K80041
Flight Recorder System Component Location 5C8
31-24-0 Figure 1 Feb 20/85
Page 2
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
C. The UFDR front panel contains a BITE indicator, test connector and an underwater locator beacon. The BITE indicator is yellow when the UFDR is faulty or power to the unit is off, black when the UFDR is operating properly. The test recorder connector allows connecting a tester to the recorder. The underwater locator beacon is a battery operated unit which transmits an ultrasonic signal when the unit is immersed in water.
D. The tape transport is a coplanar, peripheral belt driven device which contains tape, reel drive belt, two reel hubs, capstan/fly wheel, two belt idlers, tape guides and EOT/BOT (end of tape/beginning tape) sensors. Also, there are two interleaved four-channel erase heads, two interleaved four-channel read/write heads, and the primary drive belt. The primary drive belt passes through a hole in the wall of the transport to connect the drive motor with the capstan/fly wheel. A second hole is used by the wiring for the heads and tape sensors. The two holes are each lined with a feedthru, which become swollen and plug the holes in the event of fire.
E. The stepper drive motor, mounted outside of the crash-proof container, operates in a semi-slewing mode to drive the capstan/flywheel. The capstan/flywheel then drives a belt which passes over the two wheel hubs and the belt idlers. The EOT/BOT sensor switches the drive motor direction and switches tape tracks at each end of the tape. The read/write heads and the erase heads produce eight sequential tracks of recording. Tape speed is 6 inches per second with the stepper motor running either continuously or incrementally which gives a net tape speed of 0.48 inches per second.
F. The UFDR tape transport is located inside a crash proof container. The container consists of two halves with a steel outer shell and a fire insulation and fiberglass liner. A gasket is used between the two halves. Expanded material lines the belt and wire entry holes. The container is mounted to the front panel/chassis assembly with vibration isolators.
3. Accelerometer (Fig. 1)
A. The accelerometer is a self-contained sealed unit mounted on the aft side of the forward wall of the right wheel well at station 663, LBL50, WL194 and is accessible through the wheel well. On airplanes with single-axis accelerometer the accelerometer's sensitive axis is oriented to detect vertical acceleration forces with a range of -3 to +6 g's. On airplanes with 3-axis accelerometer, longitudinal acceleration forces are also detected. The unit supplies the recorder with a 400-Hz amplitude modulated signal which is a function of the acceleration of the airplane. A 26-volt, 400 Hz ac excitation voltage is provided to the accelerometer from the UFDR.
5C8
Jun 20/88 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 31-24-0 Page 3
4. Flight Recorder Test Module
A. The flight recorder control panel, part of the FLIGHT RECORDER AND MACH AIRSPEED WARNING MODULE, contains a TEST NORMAL switch and an OFF light.
B. The push to-test flight recorder OFF light, when illuminated, provides indication that the flight recorder is inoperative. A ground for the light is completed through a de-energized power relay in the flight recorder when flight recorder power is not available, or when ground is completed by a 15-second time delay circuit if the tape in the flight recorder is broken or fouled.
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