Page:Aviation Accident Report, United Air Lines Flight 4.pdf/11

- 10 - properly during the approach of the trip.

Under United's standard instrument procedure for trips approaching Salt Lake City, the north leg of the Salt Lake Radio Range and the south leg of the Ogden Radio Range, which overlie each other, are used. As a supplement to the monitoring of these legs which is accomplished by personnel and instruments on the ground, the approach procedure includes provision for a check, by the pilot, of the alignment of each of the two legs. On trips approaching from the west, the pilot tunes the aural long wave receiver to the Ogden range while approaching the Salt Lake Range Station in order to check the alignment of the south leg of the Ogden Range. If that leg bears on the Salt Lake Range Station, the procedure into Salt Lake is started, using the south leg of the Ogden Range northbound as far the Layton Marker. Constant back bearings are taken with the ADF tuned to the Salt Lake Range. At the Layton marker the alignment of the south leg of the Ogden Range is compared with that of the north leg of the Salt Lake Range. If legs coincide, a procedure is made and the low approach into Salt Lake is completed with both the long wave receiver and the ADF tuned to the Salt Lake Range.