Piper Arrow PA-28R-201 Pilot Operating Handbook page 464

Technology
4.5 Line of sight
Compatible FLARM
determined by the type, installation
aircraft. Under optimum conditions the internal a ntennae can give a head-on range of up to 5 km; normally,
range isabout 2 km. The radio signals can only be received by line of sight. There isno FLARM
between two aircraft on opposite sides ofthe same mountain.
4.6GPS
FLARM has to know its current position inorder to operate. For this reason, FLARM
presence of good quality three-dimensionalCF'S reception. GPS reception is greatly influenced by the
installation
closeto mountain slopes and inareas known for poor reception. If the installation is poor the GPS
quality may be reduced. In particular,
operation as soon as the GPS
4.7 Pressurized
FLARM use an internal pressure sensor to determine the pressure altitude. This isan important element to
verify the GPS
ina pressurized aircraft the FLARM
external static port.
4.8 Predicted
When close up, when two aircraft are atthe same or similar height, or GPS
bearing indication is imprecise and fluctuates.
calculates the predicted flight path of the aircraft towhich itisfitted forlessthan the next 30
FLARM
seconds. This prediction isbased on immediate past data, current position- and movement
movement
number ofuncertainties t hatincreasewith an extension ofthe forecast time.There isno guarantee thatan
sircraft will a ctually followthe predicted flight p ath. For this reason, the warning issued will notbe accurate in
all cases.
4.9 Effect of wind
Movements calculated by the GPS
may be a substantial d ifference between aircraft h eading and track, leading to a distortion ofthe threat
bearing, If the wind speed isone third ofTrue Airspeed (TAS) and the yaw-free aircraft Heading is
wind, then the threatindication displayed has an errorofabout 1 8. If the wind is very strong, the Track can
deviate up to180, from Heading. Under such circumstances and when circling, the warnings given are
unusable.
4.10 Data
The transmitter h as no effect on what the receiverinthe other aircraft does withthe data.Itis possible that
thisdata may be captured and stored by other aircraft, or by ground stations, or used forother purposes.
This opens up a range of possibilities,
generation of an sailplane launch loggingsystem, aircraft tracking, last position recovery), while others may
not be (e.g. detectingtailing ofother aircraft, airspace infringements, f ailure totake avoiding action prior to a
collision).
though this isnot recommended
atone-minute intervals, making a back-tracedifficult.
Swiss FOCA
Revision Orloinal
HB-PQY, Page: 9-520-(7)
ft
unitsmust be within range inorder to provide a warning. The range is very much
and position of the radio antennae, plus the relative p ositions o f the two
signal quality
and position ofthe antenna, and aircraft attitude. This is particularly true duringturns, when flying
there can be rapiddegradation of height calculations. FLARM
receptionquality is adequate.
cabin
positioning quality and to ensure an accurate and smooth altitude p rocessing. When
system will not Operate correctly u ntil itis property connected toan
flight path and
accuracy
prediction model thatis optimised forthe respective user.This forecastisassociated with 5
relatetoa fixed system ofterrestrial
protection
some ofwhich maybe
When FLARM makes a transmission, the signal also bears identification.
configure the unitso thatidentification
approved
Issued: MARCH 14, 2006
AIRCRAFT FLIGHT MANUAL
will onlyoperate inthe
reception is poor, the vertical
coordinates.In strong wind there
inthe pilots own interest, ( e.g. automated
The user can --even
is generated randomly and alters
SUPPLEMENT
signal
signal
resumes
installed
data, plus a
oo
out of
Date 14.03.06
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