Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 309 / 1956

PAGE 13
Feb 28/07
2D7
21-30-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
WARNING: DO NOT OCCUPY CABIN DURING TESTS.
CAUTION: TEST STAND OPERATOR MUST CONTINUALLY MONITOR STAND
OPERATION DURING ALL TIMES THAT CABIN IS PRESSURIZED. DURING
INITIAL PRESSURIZATION, ENSURE BY INSPECTION THROUGH COCKPIT
WINDOW THAT AIRCRAFT AND CABIN ALTITUDE, AIRSPEED, AND RATE OF
CLIMB INDICATORS ARE STABLE AND UNAFFECTED BY CABIN PRESSURE.
ANY OF THE ABOVE INSTRUMENTS BEING AFFECTED INDICATES A LEAK
IN THE STATIC SYSTEM. CORRECT BEFORE PROCEEDING.
(8) Start airflow into fuselage slowly and at a rate not to exceed 1,500 feet per minute rate of
change in cabin altitude.
(9) When cabin differential gauge indicates one (1) pound per square inch differential (psid),
maintain only sufficient airflow to hold one (1) psid. Inspect complete cabin structure, bleed air
system, outflow and safety valves, etc. Identify major leaks for corrective sealing/repair.
(10) Continue to pressurize the cabin at a rate not to exceed 1,500 feet per minute until a maximum
cabin differential of 5.25 psid occurs. Determine airflow required to maintain 5.25 psid and
record. If airflow exceeds 40 SCFM*, or a major leak is occurring in one or more places, or if
excessive noise is found, identify for corrective sealing.
NOTE: If cabin will not pressurize above 1 psid due to excessive leakage:
(a) Disconnect cabin controller line at outflow valve.
(b) Pressurize to not more than 5.25 psid to identify all leaks.
(c) Repair leaks.
(d) When an acceptable leak rate is achieved, depressurize cabin.
(e) Connect cabin controller line to outflow valve.
WARNING: DO NOT EXCEED 5.60 MAXIMUM DIFFERENTIAL PRESSURE IN NEXT STEP.
EXCESSIVE PRESSURE CAN CAUSE STRUCTURAL DAMAGE OR
PERSONAL INJURY.
(11) Continue to pressurize the cabin at a rate not to exceed 1,500 feet per minute until either the
outflow or safety valve starts to relieve. Note differential pressure and which valve operated.
Correct operating range is 5.50 + 0.1, - 0.15 psid.
(12) Lower cabin pressure to 4.0 ± 0.2 psid.
(13) Plug the ambient sensing port of the valve which operated above.
*
SCFM = CFM obs
[( )( )]
P obs + 2 9 . 9 2
2 9 . 9 2
520 ˚F
T obs + 460 ˚R
Where: P obs = PSID observed x 2.036
T obs = Temperature (˚F) observed
CFM obs = Cubic Feet per Minute observed
SCFM = Standard Cubic Feet per Minute (flow)