Optional Equipment
Emergency Floats
CSP–520N–1
MD 520N (500N) ROTORCRAFT FLIGHT MANUAL
TM
Original
9–20
FAA Approved
PART IV
NORMAL PROCEDURES
Preflight checks:
Check condition and security of stowed float package.
Check pressure gauge in each float package. If the pressure vessel is at
70
°
F (21.1
°
C), the pressure should read within 3000 to 3500 psig (Ref.
Figure 9−7).
Indicated gauge pressure will increase (decrease) approximately, as tabu"
lated below, per 1
°
F (1
°
C) increase (decrease) in temperature of the pressure
vessel.
Charge
Pressure
Psig
°
F
Psig
°
C
3000
5.7
10.2
3100
5.9
10.5
3500
6.6
11.9
Set BAT−EXT switch in proper position (BAT when using rotorcraft battery.
EXT when using an external power source.)
Check FLOATS circuit breaker IN.
Press to test green float
FLOAT
P TEST
LH/RH
indicator. LH and RH indicator lamps
should illuminate indicating that each circuit is operational.
Landing:
Tail–low landings on hard surfaces should be avoided, as stress
damage to the float extensions may occur.
In−flight float inflation data:
Float inflation time and altitude required for deployment are presented be"
low. Time is affected by temperature. Deployment altitude is based on a sta"
bilized autorotational rate of descent of 1800 feet per minute. It was calcu"
lated using the tabulated float inflation time, and a two second increment
for pilot reaction time:
Float Inflation Time
9.0 sec Temps up to 21
°
C
6.3 sec Temps above 21
°
C
Altitude Required For Deployment
370 feet Temps up to 21
°
C
280 feet Temps up to 21
°
C
CAUTION
