Propel RC Air Recon User manual

I NDOOR HELICOPTER WITH CAMERA
USER MANUAL
WARNING AIR RECON 1s an 1ndoor 1nfrared hel1copter Infrared Signals cannot
functiOn 1n daylight due to mterference from the sun In add1t1on, your AIR RECON
helicopter 1s not su1ted to handle wmd or other outdoor enVIronmental cond1t1ons
Anemptmg to fly th1s helicopter outdoors may lead to severe damage
THIS PACKAGE CONTAINS :
Colors and styles may slightly vary .

TABLE OF CONTENTS
Feature s ..
Remote Battery Installation .. ....•......•.. •.
Charging the Helicopter ......... ....•......,..•..
H
elicopter diagram, Remote Cont rol diagram . . ..•......•..•... ,..•. . ....... 3
Preparing for Flight ........ ................ .. ..... 4
Ho w to Sy nc your Helicopter. .... .. ..... .. ....... . ....... 4
Demon st r atio n Mode ... . ..... 4
Flying Tips ......... .. ............ .. .... ... 4
Und erstan ding He li copte rT ri m Adjustments ............ .... ....... . ...... . ...... . .. . ...... 5
Basic Flight Control s.. ........ ..... ........... .. . .. . ...... 5
Turbo And Light Buttons .......................... . .......... 5
Advanced Flight Contro ls ............ . ................ 6
Us
ing Yo ur on Board Ca m era an dVid eo R ecor de r. .. ...... ... ..... ...... . ......... 7
H elicopter Warni ng And Safety Precautions.... ............. .. ............. ....8
Part Replacement In st ru ctions ... .. ........ .. ... .. ..... .. .. ... .. ........... .. .... .. 9
Contents . ..... ... .................................. .. 9
Air recon Propeller System. ... .... ........ .............................. .. ..... . ..... 9
Replacing the Upper Propeller Blade .............•..• .. .. .•......• .. •...• .. •......•......•. .. . 10
Replacing the Bottom Propeller Blade ... . ........ .........................................10
Battery Warning s ................ ................ . .. ................. 11
Care and Maintenance .............•.... .................... .. .. 11
FCC Informa ti on . .................................. . .. ....................... 11
Thank you for purcha s ing the AIR RECON ™3 Channei iR Gyro Helicopter . Please read this in s truct ion booklet
ca refully as it contai ns valuable information on how to properly fly an d ca re for your helicopter .
FEATURES
• Built-in gyroscopic chip for ext r eme stabi lity and co ntrol .
•
Turn s like ar eal helicopter - even hovers in mid - air .
• 3 Channel : fly up , down ,l eft, right , foiWard , backward .
• Full - function i nfr ared r emote al so charges h elico pt er.
• Mu l ticolored blinking LEOs ca n be turned on / off remotel y.
• Two speeds beginner and Turbo for accelerated fun .
• Records video footage on Micro SO cards
• Tak es sti ll Photo shots
• Included de monstrat ion mod e sh ow s the flight function of th eh elicopter

REMOTE CONTROL BATTERY
INSTALLATION
1. Pull the battery cover off of the remote cont r ol.
1.1nsta ll 6" AA' ' alkaline batteries as shown in the diagram .
3. Replace the battery cover.
CHARGING THE HELICOPTER
0
A: FROM THE CONTROLLER:
l.Openupthechargercovertotheopenpositiononthe rightsideofremote
control(seediagramB).
2.Makesuret heh elicop t erpowerswi t chisset t otheOFF po si ti on (see
diagram A&(). All l ightsand propel! eo s hould be off.
3.Connectthechargingplugo n theremotecontro lt othechargingsocketon
thesideofthehelicopter{seediagramA&D). "
4. Turn the controller power swi tch to the ON position (set diagram E ).
T he green charging indicator light on upper right side of the controller
will illuminate to indicate c harging is in prog r ess.
5. The gr ee n charging indicator light will s hut-off when the helicopter is
fully charged .
6. L ength of c harg ing time will vary depending on percentage of
helicopter battery already charged and the condition of the batteries in
the controller . Average charging time is 25 -3 0 minutes with new
batteries. The heli co pter o perat es for app r oximately 6-8 minutes
per charge .
B: FROM THE USB CABLE:
1. Plug the included USB charging cable into a USB port on yo ur
com puter .Pl ease make su re that yo ur com puter is turned on .
2. Make sure the heli co pter Power Switch is in the " OfF • position (see
diagramA&D ).
3.Whenthehelicopterischargingtherewillbenolighto nt opofthe
USB body that connects to you r compute r. When charg ing is comp l ete a
red LED l ight will appear on top of the USB body that connects to your
computer (see d iagram F). USB c harging time may vary depending on th e
amount of charge needed to fill the h elico pter battery . The average USB
chargingtimeis1S-30minutes .
Battery Compartment
(6 " AA "b atteries)
IMPORTANT : ALWAYS DIS<ONNECT CHARGER CORD AFTER CHARGING . NEVER LEAVE CHARGER CONNECTED TO HELICOPTER
OVERNIGHT OR FOR EXTENDED PERIODS OF TIME .
(.
E.
NOT£ Chargmg socket 1slocatedonthebacks1drofthrhehcoptrr Chargmgcordconnrctsas
1nd1cated lndlcatorhghtonchargerstaysonuntllchargmglscomplrtrd

HELICOPTER DIAGRAM
Below is a basic list offeatures and part s on the helicopt er.
REMOTE CONTROL DIAGRAM
Be lo w is a basic li st of features on the infrared wireless remote control.
Throttle Control
-- Stabilizer bar
Charging
Cord Cover
Camera S nap - +-- --- ----' ~- !?'
'is;;~'- --- -++ - Trim Controls
Shot Button
Start / Stop
+t- -'r --- Video Recording
Button
-!+ - +- --- Helicopter
Demonstration
NOTE When fly1ng your A1r Recon w1th other mfrared helicopters make sure that each helicopter IS set to operate on a
dlfferentmfraredchanneltoavoldlnterferencewhenflymg Seebackpanelforaddl!lonalprecautlons

PREPARING FOR FLIGHT
• Verify that there are 6 "AA'' batteries inside the infrared remote control unit and the helicopter has been fully cha rg ed.
·Make sure your helicopter is turned on and properly synced to your controller. (See "SYNC YOUR HELICOPTER " below)
·Make s ure to be in a large room with an open radius of at l east 25 feet. Cl ose all windows and doors, turn off fans and
close air duct s or any other openings that may cause drafts in the room.
·Make s ure the room has no obstacles and the highest ceil ing pos sible. DO NOT A TTEMPT TO FLY YOUR HELICOPTER
OUTDOORS. Set your helicopter on a dean flat s urfac e before t ake-off.
HOW TO SYNC YOUR HELICOPTER
Your AIR RECON™ utilizes an automatic multi -c hann el se l ection system that allows up to 3 people to fly side by side
inthesamewirel essrange.
FOR ONE PERSON PLAY:
1. Before starting, make su re that both your controller and helicopt er are in the power " OFF " position .
2. Se l ect the desired flight channel (a, b or c) from the controller and turn the controller on (see diagram Eon page 2).
Make su re your t hrottl e stick is all the way down and in the off position.
3. Next, turn on the helicopter and set it on a table or hold it in your h and from underneath . Make sure your hands and
body are away from the helicopter blades. ~
4. There will be slight delay and then the helicopter multi ~ colored "s ide body lights " will begin to flash. When the side
body lights begin to flash your helicopter is synced and yo u are r eady to fly.
6. Note: if you turn your h elicopter off or the battery runs out, you will need to re ~sy nc the helicopter and controller.
FOR MULTI PERSON PLAY:
7. Before starting, make sure that All the helicopters and controllers are in the power " OFF " position.
8. Each individual player must select a different flight chan nel (a, b or c) on his / her own controller. If more than one
person is on the same flight channel, there will be interference .
9. Only one person at a time should sy nc their helicopter by following ste ps3 thru 5 above. Remember to make sure
that each player chose a different channel befo re anyone begi ns to sync their h elicopters. If a mistake is made when
" pairing " helicopte rss imply turn off all the helicopters , make sure all players are set to different cha nnel s and start
again, one by one.
10. When apl ayer's helicopter is synced and wo rking it shou ld be l eft on while the next player's sync their helicopters.
11 . Note if you turn your helicopter off or the battery runs out, you will need to re ~s ync the he l ico pter and controller.
DEMONSTRATION MODE
Your AI R RECON™ wi rel ess infrared remote contro l helicopt er has a unique demonstration mode that sh ows you
some of the basic maneuvers and flight functions that your helicopter is capable of. To activate the demonstration
simply hover your AIR RECON ™ helicopter slightly above eye-leve l in the centre of clear open room with no
obstacles and press the " DEMO " button on the front of your contro ll er (See " CONTROLLER DIAGRAM " on page 3).
NOTE : once the demo button is depressed do not move I touch the Throttle or Direction Control sticks.
To exit demonstration mode simp ly move the Throttl e stick or Direction Control stick.
FLYING TIPS
·It is recommended that you operate the helicopter in a wide indoor space. You shou ld allow at least a 25~foot radiu s
range. The helicopter is designed for INDOOR USE ONLY .
·Par
ental guidance or adult supervision is suggested at all times .
·If you are flying the helicopter with others, make sure all spectators are behind you.
·For best performance , it is recommended that you operate the helicopter in zero wind conditions. Close all open doors
or windows, and turn off any nearby fans. Wind can greatly affect the performance of the helicopter .
NOTE Beforeactlvatmgdemonstratlonmodeyoushouldmakesurethatyourhehcopterlsfullychargedandthat
youhaveaclear25footradluswl thnoobstacles

UNDERSTANDING HELICOPTER TRIM ADJUSTMENTS
If you rhe licopt er nose rotat es to the left or right uncontro ll ab l y, yo u may n eed to utili ze the T RIM button s. If you r
helicopt er over rotate s CLOCKWISE (to the right), pu sh and re l ease the LEFT si de ofT rim bu tton repeatedly until th e
turning stops and proper flight is maintained. If you r helicopter over r otates COUNTER -CL OCKWISE (to the l eft), push and
re leas e the RIGHT side ofT rim button in the same manner un ti l the prob l em isr esolved. Fr om time to time you may have
to adjust the left and right trim to ensu re the helicopter will fly straight and respond accu r ately to cont rol com m ands.
Trim Controls
lf overrotatestotheright...
{g(V Pushlefttrim.
('g[YPu sh r ighttrim.
BASIC FLIGHT CONTROLS
Below is a list of basic flight functions for your Ai r Recon ™ wire l ess infrared remot e control he li copter. While
learning to fly your heli co pter it is best to start with a large room until you get u sed to the basic co n trols. As you
m as ter flying your he li copter you can move to more advanced maneuvering technique s.
t
Move the Throttle froward to increase the speed
of the main rotor and the helicopter will ri se up .
Move the Direction Control l eft and the helicopt er will
turn l eft.
Move the Direction Control forward and the helicopter
will move forward.
TURBO AND LIGHT BUTTONS
~
Move the Thro ttle backwards to decrease the s peed of
the main rotor and the helicopter w ill descend .
~
Move the Direction Cont rol right and the he li copter w ill
tu rn right.
Move the Di r ection Control backward s and the
he licopter will mov e backward .
Press the TURBO button on the front of the controller {see CON TROLLER DIAGRAM pg 3) and you r AIR RECON TM helicopter wi ll
change into high -s peed mode . Press the TURBO bun on a secon d time to go back to the original s peed . Press the LIGHT button on
the face of the controller (see CONTROLER DIAGRAM pg 3) to r emotely sw it ch helicopter lights off and on.

ADVANCED FLIGHT CONTROLS
Once you have mastered the basic flight controls of your AIR RECON TM Infrared Indoor Helicopter its time to try your
hand at some more advanced flying techniques like forward and reverse sweeping turns .
1. To make a forward sweeping turns , first push the Direction Control straight s tick all - the - way forward until the
control stick touches the upper edge of the controller . (see Diagrams A and 8, step 1 below) . You s hould be
moving straight forward at this point.
l. Secondly begin to slowly roll the Directional Control stick along the outer edge towards One O' Clock to sweep
right or Counter - Clockwise along the outer edge towards Ten O'Clock to sweep left ( see Advance Flight Maneuvers
diagrams A and 8 below steps 1 and 2) .
3. To do reverse sweeps simply reverse the Control Stick by moving first directly to the lower or backwards edge of the
controller, then begin to roll the control stick slowly along the outer edge in the direction that you want the
hel icopter to sweep in reverse. Remember you must first h ave reverse momentum before attempting a sweep or you
will sim pl y turn in place .
4. Once yo u get familiar wit h flying your AIR RECON rM helicopter you can begin to fly higher and faster , making
quicker turns and practicing new tricks .
.-------:-- A_o_v_A_N_C_E_D -, FLIGH J MA r- N- EU _V_E_R_s _______ ~
NOH To make mce sweep1ng moves you will need to first be movmg forward at a decent pace In order to ach1eve th1s you
should depress the TURBO button on the front of your controller and make sure you are m fast Speed mode before you brgm

USING YOUR ON BOARD CAMERA AND VIDEO RECORDER
Your AIR RECON TM Indoo r wireless helicopter comes equipped with an on boa rd digital camera that takes both Video
and still Photographs. Now you can have hou11 of fun creating aerial photography an d videos for family and frie n ds.
WHA T YOU WI LLN EED TO GET STARTED US I NG YO UR CAMERA
1. One M icr o SO ca rd {i ncl u ded)
2. One Micro SO card rea d er (inclu d ed)
3. One Computer wi th USB po rt and Windows Media Playe r or other Media player that ca npl ay AVI files (not in cl u ded).
FORMATTING Y OUR MICRO SO CARD
Before you can be(] in to take videos or digital photographs you must first fonnat your Micro SO card. To format yo ur
Micro SO card simply place the Micro SO card into the included USB SO card reader and pl ug it into your computers USB
port (See diagram 1 and 2 below). After a few moments an icon will appear on your Desktop. Right dick on the Icon
and follow instructions to format your Micro SO card.
INSTALLING THEMI CRO SO CARD IN YOUR AIR RECON '" HELICOPTER
·Make sure helicopter is in the powe r "OFF" posit i on.
• Place the fo r matted SO card in to the back of the helicopters digital camera port. ( see diag r am 3 below) Push gently
and consistently until you hear and feel the micro SO card ~ dick" into the digital camera slot
·Tum the helicopter on and make sure that it is both fully charged and properly synced to the Controller (see HOW TO
SYNC YOUR HELICOPTER on page4) .
·When you have successfully installed you r micro SO card and your helicopte r is in the power ~ ON " position , you will
see a solid green l ight on the helicopter cameras belly. This green light is accompanied bya sepa r ate fl ashing r ed light
on its side. Th is r ed l ed light sho uld flash 5 times and then go off. This i ndicates you are ready to take bot h
ph
otograp hs and videos. (see ca m era in d icator light diag r am 4 below). NO TE :If you see a co n tinuous flas h ing red
l
ight th is mea ns yo u have not insta ll ed your Micro SO card corrertly or there is ap ro blem wit h your SO car d. If this
happens first make sure that t he pr oduct is not in Video Record mode and if not , th en please r eformat and try again. If
you continue to encounter problems call ou r customers service l ine at 949 . 566.9573 Ext 1 for assistance .
TAKING DIG I TAL PHOTO S
To take photographs simply press the PHOTO button on the face of the controller (refer to CONTROLLER DIAGRAM on pg
3) the red l ight on the belly of the camera will flash RED 3x. As this r ed light is flashi ng it is taking one still photo. When
the camera r eady l ight becomes green again you arer eady for your n ext photog ra ph .
RECORDING V IDEOS
To reco rda video firs t make sure that your helicopter is fully char ge dand that yo uh ave co rr ertly ins ta ll ed the micro SO
card in theH elicopters camera port . Begin recordi nga video by pressing the VIDEO RECO RDb utton on the fron tle ft side
of the controller (see CONTROLLER DIAGRAM on page 3) . The red indicator light will continuously flash RED indicating
that VIDEO recording is in progress . To stop the video recording , press the RECORD button a second time . The red
indicator light on the belly of the camera will tum OFF indicating that video recording has stopped and the Camera is in
ready mode again.
Diagram 1
Diagram 2 Diagram 3 Diagram 4

REMOVING YOUR MICRO SO CARD
To remove your Micro SO Card push in gently on the back of the SO card with your thumb or forefinger until you hear
and feel a" clicking sound ". The Micro SO card will " pop out" slight ly and is ready for removal . Simply grab and pull
gently away from the helicopter camera port to remove the card. Always store your Micro SO card in a dean, safe and
cool environment
DOWNLOADING AND CLEARIN G SPACE ON YOUR MICRO SO CARD
Plug your micro SO ca rd into micro SO card reader and conne<t to your computer . It is best to always download all your
videos and pictures on to your computer and not store this data on your Mic ro SO ca rd.
After downloadi ng you r photos and videos , follow your computers instructions to " delete " files on your Micro SO card.
IMPORTANT NOTICE : When yo ur Micro SO ca rd is full t he i nd ica tor lig ht on the bon om of your helicopter will become
solid REO. This i ndicates that its time put a new SO card in yo ur helicopter or down l oad files and clear s pace for futu re
photos and videos.
NOTICE When record1ng v1deo footage the AIR RECON
1
~' helicopter automatiCally goes 1nto slow mot1on mode
th1s allows steady controlled record1ng of v1deo footage that would not be poss1ble 1n faster fiy1ng modes
HELICOPTER WARNING AND SAFETY PRECAUTIONS
The helicopter blades revolve at hig h speeds and can cause damage to the user , spectators and animals. Stand
away from the helicopter to reduce the risk of getting into the flight path . Warn spectators that you will be flying
your helicopter so that they are aware of its position. Before flight , inspect the rotor blades to make certain that the
blades are securely fastened to the helicopter.
WARNINGS
·Choking / Cutting Hazard . Small Parts/Sharp Rot or Blades.
• Keep han d s, h air andl oose clothing away fr om the prope ll er when the power switch is turned to the ON position .
• Turn off the transmitter and he l icopter powe r switc h es when not in use.
·The remote contro lchar ge r is bui lt sp ecifica ll yfor th eh elic o pters li-P oly b attery. Do not u se it to charge any othe r
b
attery.
·New alkali nebatter ies arer ecommended form ax im um p erfo r mance.
·Par ental supervision r ecommended when fly in ghe li copter.
IMPORTANT : ALWAY SDI SCONNECT CHARGER CORD AFTER CHARGING . NEVE R LEAVE CH A RGER CONNECTED TO
HELICOPTER OVERNIGHT OR FOR EXTENDED PERIOD S OF TIME . INFRARED MULTI CH ANN EL CONTROL SYSTEM

PART REPLACEMENT INSTRUCTIONS
CONTENTS : 0
(3)4screws (1) 1 upper propeller blade
(2) 1 bottom propeller blade
a
xl
xl (4)4 connecting rods
x4
x4
AIR RECON PROP E LLER SYSTEM
Your AIR RECON propeller system isa precision instrument that may need repair or replacement from time to time for
optimal flight function . Crash landing from high -s peed aerial flight s may cause damage to your AIR RECON propeller
or propeller connecting rod s.
TRO UBL ESHOOTING:
If your AIR RECON loses it s ability to fly co rrectly , please inspect the propeller sys tem carefully for the following five
c ommon issues:
1.R eplacing the Connecting Rod : The connecti ng rod is a small ~ hand c uff' style device that stabilizes the " upper"
propellers . There is one connecting rod on the upper propeller. Please see Diagr am 1.
Ifa connecting rod is broken or mi s sing s imply replace it by " peeling ~ o ff the exis ting broken unit and r ep l aci ng it
with a new one . You may have tou se sli ght pr ess ure whe n reattaching both ends of the new connecti ng rod . Make
s ur e that the new connecting rod is sec ured and loded in pla ce . S« Diagram 2. For cha nging connecting rod , make
s ure there is no damage to the actual blade or arm that holds the connect ing rod in pla ce. If there is yo u mu st replace
the entire blade system.
2. Replacing the Upp er and Bottom Propeller : The propeller iss ubje ct to damage as you learn to properly fl y and
co ntrol your AIR RECON.If after ac ra sh your he li copte r has loss of co ntrol orfli es erratically you s hould ca refully
inspect you rentire prop eller sys tem for any s ign of damage . Mo st common are: cracked or c hipped bl ade, broken
~co nnecting rod", frozen b alance bar (thisis when the b alancing bar and bl ade are jamm ed and can not mov e freely
up and down ). To replace the propell er blades follow diagram s3 through 12 .
REPLACING CONNECTING ROD
Diagram1
Th ere are two propell er connecting
r ods on the upper propeller .
Diagram2
Broken con necti ng rod
~niE9
~~
Rep la cing connecting r od
Proper co nnection
Broken co nn ecting rod

REPLACING THE UPPER PROPELLER BLADE
Diagram
l
Using a S<rewdriver turn counterclockwise
to r emovethescrew.
Diagram
5
Using the screwdriver turn clockwise
totightenthescrew.
Pl ease note the design
oftheupperblade.
Diagram
7
Remove the broken blade and
carefully replace with a new one.
When you tighten the screw you s hould t6t the blade to make
su reth:t it still has free movement. If the blade cannot move
freely , slightly loosen the screw.
REPLACING THE BOTTOM PROPELLER BLADE
Diagram
8
U si ng a sc r ewd r ive r turn co unt er clockwise
toremovethescrew .
Di
agram
10
Using the screwdriver turn clockwise
to tighten the screw.
tG
\a
Bottom Blade
Pl ease not e th edesig n ofthe
bottom blade .
Diagram
12
Diagram
9
Remove the broken blade and
ca r efully replace with a new one.
~Diagram
111!!11 11
When you tighten the screw you should test the blade to
make sure that it still has free movement. If the blade cannot
move freely, slightly loosen the screw.
10

BATTERY WARNINGS
RECHARGEABLE BATIERY:
This helicopter uses an internalli-Poly rechargeable battery and is not replaceable . If battery no longer stays
charged, dispose of battery properly according to local disposal requirements.
CONTROllER BATIERIES :
Remote control require s6" AA' ' batteries (not included). Please read the important battery safety warning below.
·Do not mix alkaline, s tandard (carbon-zinc) and rechargeable batterie s (Nickel Metal Hydride) .
• Do not mix old and new batteries.
·Non-rechargeable batterie s are not to be recharged.
·Rechargeable batteries are to be removed from the item befor e being ch arged (if removab l e).
·Rechargeable batterie s are on ly to be charged under adult supervision.
·Exh austed batteries should be r emoved immediately and must be recycled or disposed of properly according to
state or local government ordinances and regulations.
·The supply terminals are not to be short-circui t ed.
·Only batteries of the same or equivalent type as r ecommended are to be used .
·Batteries are to be inserted with the correct polarity (see inside booklet for diagram).
·Do not dispose batteries in a fire- batteries may leak or explode.
CARE AND MAINTENANCE
·A lways remove the batteries from the wireless infrared remote co ntrol when it is not being used for an extended
period of tim e.
·To clean, gently wipe the remote control and helicopter with a dean damp doth.
· Keep the toy away from direct heat or sunlight.
·Do not s ubmerge the toy into water. This can damage the unit beyond repair.
·Parental guidance recommended when installing or replacing the batteries .
FCC Part 15 8 Notice
CAUTION: Changes or modifications not expressly approved by the party re s pon sib le for
compliance could vo id the u sers authority to operate the equipment.
NOTE: This equipment has be en tested and found to comply with the limits for aCl ass B digita l
device, pur suantto Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation . Thi s equipment generates,
uses and can radiate radio frequency energy and, if not installed and used in accordance with the
instruction s, may cause harmful interference to radio communications. However ,there is no
guarantee that interference will not occur in a particular in sta llation .If this equipment doe s cause
harmful int erfe ren ce to radio or television reception , which ca n be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one or more of
the following measures:
Reorient or relocate the receiving antenna.
• Increase the sepa ra t ion between the equipment and receiver .
• Connect the equipment into an outlet ona circuit different from that to which the r eceiver is connected.
• Consult the dealer or experienced radio/TV technician for help.
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) th is device may not cause harmful interference, and
(l) this device must accept any interference r eceived, including interference that may cause undesired
operation.
Conforms to safety requirements of ASTM, CPSIA and FCC.
PROPEL RCTM and AIR RECQNTM are trademarks of Rooftop Brands.
<C> 2012Rooftop8rands™ Allrightsreserved
Tel :+ 01 949·566 · 9573 • WWN . rooftopbrands . com
Made in China
11
& WARNING!
CH O KIN G HAZA RD - Small parts.
Nolsuilablelorchildrenunder3years .