UBLIC HEARING: Director of Development ... - City of Glendale

Arup Acoustics
Ms. Ricarda Bennett
May 15, 1996
Page 3
PAST HELIPORT OPERATIONS
OPERATION INFORMATION
Historical flight operation information from Heliport Consultants shows that the Heliport at Crystal
Springs Site has been active since 1958 facilitating flight activities by Heliport Inc. and various
police departments. The actual flight information, however, is available only for the time period of
1974 through 1992. During this period the Los Angeles Police Department (LAPD) and the
combined Glendale/ Burbank Air Support Units used the heliport facility, for various helicopter
operations such as patrol, sUNeiliance and training. Table-2 presents the historical flight
operations classified into three time categories of daytime. evening time and night time to
correspond to the time categories associated with calculation of the CNEL noise metric.
These ,time classifications illustrate the number of takeoff and landings (noise events) associated
with the weekday use of the heliport during the daytime hours of 7:00 a.m.- 7:00 p.m., 7:00 p.m.­
10:00 p.m., and 10:00 p.m.- 7:00 a.m. In general, the heliport site was used more frequently
during weekdays than weekends. Thus, in order to represent the worst noise scenario, the
weekday operation volumes were used to calculate the previoUS CNEL values.
Table 2 - Historical Operation Flight-Events at Glendale Crystal Springs DWP Site
Operation Number of Events Per Day
Period (Year) Police Department (Per Time Category) Total
0700-1900 1900-2200 2200-0700 (Per Week Day)
1974-1977 LAPD 65 13 16 94
1978-1983 LAPD/Glendale/Burbank 105 28 26 159
1984-1988 Glendale/Burbank 40 15 10 65
1989-1992 Glendale 35 '10 4 49
TYPES OF HELICOPTERS
Different types of helicopters utilized the heliport site in connection with previous flight operations
by LAPD and Glendale/Burbank police departments. Information from Heliport Consultants
indicates that, during the "peak" years of operation (i. e. the highest number of helicopters per
year), LAPD employed a fleet of helicopters that included primarily the Bell 47 and Bell 206. The
Glendale/ Burbank air support fleet included mainly Hughes 300 helicopters.
Table 3 represents the fleet mixture for "peak" years and for both LAPD and Glendale/Burbank Air
Support units. A statistical analysis of the helicopter fleet mixture was carried out in order to
calculate the probability of a specific type of helicopter being used in a typical weekday flight
operation. Table 3 illustrates the estimated probability of occurrence of various helicopter types in
a typical operation. As can be seen, the results of the statistical analysis indicate that LAPD's fleet
operation used Bell 206 and Bell 47 helicopters more frequently than Bel! 204 and Hughes 500
helicopters.
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