Descent - Piper PA 28-181 Manual

SECTION,I
NORMAL PROCEDURf,S
PIPER AIRCRAFT CORPORATION
PA.2&181, ARCHf,R II
Use of the mixture control in cruising flighl reduces luel consumption
significantly, especialiy at hisher altitudes. The mixture should be leaned
during cruising operation above 5000 ft. altitude and ar pilot\ discretion al
loweraltitudeswhenT5%powerorlessisbeingused.
Uanydoubt€xistsasto
the amount of power being us€d. the mixture should be in the full RICH
position for all operations under 5000 feet.
To lean the mixture, disengaSe the lock and pull the mixture conrrol
until the engine becomes rough, indicating that the l€an mixture limir has
been reached in the leaner cllinders. Then enrich rhe mix(u'e b! pu:hina the
control tosard\ rhe rnctrumenr panel unril engine operario; becornes
lf the airplane is equipped with rhe oprional exhaust gas remperarure
(EGn gauge. a more accurare means or leanina i' availdble ro lhe pilor. Be,t
economy mrxrure i\ oblained by moting the mr\lure control afl ünrrl peaI
LC I !i reached. Berr power mrxlure is obrained by leanrng ro peak FcTand
then €niich€ning until the EGT is 100'F. rich ofthe p€ak value. Under some
conditions of altitud€ and throule posirion, thi engine may exhibit
roughn€ss before peak EGT is reached. If this occurs, rhe EGT
co-rresponding to lhe onset of engine roughness should be us€d as the peak
Always remember that the electric fuel punp should be rürned ON
before switchingranks, and should beleftonforashorlperiodthereafter.
In
order to keep the airplane in besr lateral trim during cruising fligh! the fuel
should be used altemat€ly from eachtank. lt is recommended rhal onetank
be used for one hour after takeoff, thenrhe orherrank beus€dfortwohours:
then rerurn ro rhe firrl tank. $hich \aillbaveappro\rmälel)
oneand one hali
hours of fuel remaining ifthe tanks were full at takeoff. The second tank will
coniain approximately one half hour offuel. Do nor run lanks complet€ly
dry rn flrghr. The elec rc fuel pump,hould be normally OFI \orhär an!
malfunction of lhe engine dri!en iuelpump is immediatel) dpparenr lr sign,
snouro occur al dny ume dulng rghl, ruet exhaustlon
should be suspe€led, at which time lhe fuel selector should be immediately
positioned to lhe other tank and lhe elecrric fuel pump swirched to the ON
4.29 Df,SCENT
NORMAL
To achieve lhe performance on Figure 5-29 the power ondescenr musr
be used. The throttle should be set for 2500 RPM. mixlure full rich and
maintain an airspeed of 122 KIAS. ln cas€ carburetor ice is encounrered
apply full carbureror heat.
REPORT: YB-1120
+1E
ISSUED: JULY 2, 1979
REVISEDT JULY 5, l9ts