Request for amendment to FAA 333 UAS exemption, Exemption No. 11530

Regulatory Docket No. FAA-2014-00346, dated May 7, 2015

Contact: Bill Reynolds, President and CEO

407-468-0008 

Leading Edge Associates (LEA)

Email: breynolds@leateam.com 

Website: www.leateam.com
Date: 

Re: Exemption No. 11530

Regulatory Docket No. FAA-2014-0346

Leading Edge Associates, Inc. (LEA) is requesting amendment to our existing 333, Exemption No. 

11530 Regulatory Docket No. FAA-2014-00346, dated May 7, 2015 as listed and described 

below. As stated in our original 333 Exemption, we request under 14 C.F.R §§ 61.113(a) & (b), 

91.7(a), 91.121, 91.151(b), 91.405(a), 91.407(a)(1), 91.409(a)(1) & (a)(2), and 91.417(a) & (b), to 

operate an Unmanned Aircraft System pursuant to Section 333 of the FAA Modernization and 

Reform Act of 2012 (FMRA). 

If this amendment is approved, we request FAA extend the date of expiration accordingly. This 

certificate FAA-2015-0346-333E is effective from May 9, 2015 to May 31, 2017.

1. Additional Aircraft

The purpose of this amendment request is to increase the flexibility of airframes offered to 

customers and to provide PrecisionVision 5 (PV5) with different flight characteristics than the 

PrecisionVision 10.

Unmanned Aircraft System: PrecisionVision 5 UAS

Leading Edge seeks an exemption to operate the Leading Edge PrecisionVision 5 UAS for 

compensation or hire within the NAS. The PrecisionVision 5 is a Vertical Take-Off and Landing 

(VTOL) Remote Piloted or Unmanned Fully Autonomous quad helicopter, which is batterypowered by four brushless motors with the option of two additional brushless motors (6 in all). 

An Autonomous Flight Control System (AFCS) is an integrated module mounted on the 

PrecisionVision 5. The AFCS receives commands from a ground control station via a wireless 

telemetry system and controls the actionable flight controls. The PrecisionVision 5 has a 

maximum gross weight of approximately 5.5 pounds, while having a length of 16 inches, width 

of 14 inches, height of 9.8 inches, and maximum speed of approximately 15 knots. The 

PrecisionVision 5 is equipped with a three cell battery, 802.11 Telemetry (2.4 GHz, 5.8GHz), 

Manual Controller 2.4 GHz line of sight range (LOS), climb rate 2 meters/sec., max. altitude 300 

feet and a 15-minute endurance. The PV5 will return to take off position when 25 percent of 

power remains.

The PrecisionVision 5 that will be operated by Leading Edge will be registered in accordance 

with 49 U.S.C. 44103, Registration of Aircraft, as well as 14 C.F.R Part 47, Aircraft Registration, 

and marked in accordance with 14 C.F.R. Part 45, Identification and Registration Marking. 

In consideration of the size, weight, speed, and limited operating area associated with the 

unmanned aircraft and its operation, Leading Edge’s operation of the PrecisionVision 5 meets 

the conditions of FMRA Section 333 and therefore, will not require an airworthiness certificate 

in accordance with 14 C.F.R. Part 21, Subpart H. 
Accordingly, Leading Edge requests relief from Sections 91.405(a), 91.407(a)(1), 91.409(a)(1) & 

(a)(2), and 91.417(a) & (b), as these sections set forth requirements for maintenance that only 

apply to aircraft with an airworthiness certificate.

Leading Edge submits that the requested relief is proper since an equivalent level of safety will 

be ensured. Leading Edge will use trained technicians to perform maintenance, alterations, or 

preventive maintenance on the UAS using the methods, techniques, and practices prescribed in 

the operating documents (i.e., the PrecisionVision 5 Operation Manual, Maintenance Schedule 

and Manual, Airframe Maintenance Manual, and Spectrum DX8 Instruction Manual). 

Furthermore, Leading Edge will document and maintain all maintenance records for the 

PrecisionVision 5.

Relief from certain requirements of Section 61.113(a) and (b), entitled Private pilot privileges 

and limitations: Pilot in command, is requested by Leading Edge to the extent necessary to 

allow a Pilot in Command (PIC) holding a private pilot, recreational or sport or higher level 

certificate and who has demonstrated, by meeting minimum flight- hour and currency 

requirements, that the PIC is able to safely operate the PrecisionVision 5 in a manner consistent 

with this exemption, including evasive and emergency maneuvers and maintaining appropriate 

distances from people, vessels, vehicles and structures.

Leading Edge seeks relief from Section 91.7(a), entitled Civil aircraft airworthiness, because the 

PrecisionVision 5 does not require an airworthiness certificate in accordance with 14 C.F.R. Part 

21, Subpart H. As such, Leading Edge submits that it will ensure that the PrecisionVision 5 is in 

an airworthy condition, prior to every flight, by determining that the system is in compliance 

with the operating documents (i.e., the PrecisionVision 5 UAS Operation Manual, Maintenance 

Schedule and Manual, Airframe Maintenance Manual, and Spectrum DX8 Instruction Manual), 

and that the aircraft is in a condition for safe flight. 

Leading Edge also seeks an exemption from the requirements of Section 91.121, entitled 

Altimeter Settings, as the PrecisionVision 5 will not have a typical barometric altimeter onboard. 

However, altitude information of the PrecisionVision 5 will be provided to the PIC via Global 

Positioning System (GPS) equipment and a radio communications telemetry data link, which 

downlinks from the PV5 to the GCS for active monitoring of the flight path, flight parameters, 

battery power level and other data sets. This altitude information, combined with Leading 

Edge’s operation of the PrecisionVision 5 within visual line of sight, at or below 300 feet AGL, 

will ensure a level of safety equivalent to Section 91.121.

Additionally, Leading Edge seeks an exemption from the requirements of Section 91.151(b), 

entitled Fuel requirements for flight in VFR conditions. Leading Edge submits that safety will not 

be affected by operation of the PrecisionVision 5 during daylight hours in visual meteorological 

conditions (VMC) under visual flight rules (VFR), with enough battery power to fly for a total 

duration of 13.5 minutes to the first point of intended landing and, assuming normal cruising 

speed, to fly after that for at least 4.5 minutes (i.e., 25 percent battery power remaining). 

In accordance with 14 C.F.R. § 11.81, Leading Edge provides the following information in 
support of its petition for exemption:

Name and Address of the Petitioner. 

The name and address of the Petitioner is: 

Bill Reynolds

Leading Edge Associates, Inc. 

702 Tulip Tree Court 

Fletcher, North Carolina 28732

Remote Piloted Aircraft (RPA) in support of LEA customers requires a mix of aircraft and will 

further enhance safety of lives by eliminating humans having to traverse through rugged 

terrain, swamps and marshes, yards, vacant lots and throughout the agriculture and mosquito 

areas. LEA customer base is rapidly expanding throughout the United States as illustrated by 

the map below and these additional RPA will permit us to adjust to various conditions and flight 

missions. The map below illustrates our broad customer base and to why we need a variety of 

platforms in a variety of terrain and weather conditions to carry out data acquisition missions.

According to most scientist, global warming, whether permanent or temporary, will cause an 

increase in vectors which carry diseases such as Zika, Chikungunya, Dengue and West Nile virus. 

All have been identified in one or more of the 50 states.

Under exemption 11530, FAA-2015-0346 LEA has flown PrecisionVision 10 missions for the 

Florida Keys Mosquito District located in the Florida Keys and provided data otherwise unable 

to be acquire by other means. We wish to expand this capability throughout the United States. 

The PrecisionVision 5 will be flown on similar missions
A grant of exemption is in the public health interest as the breeding grounds for mosquitos 

infected with the above mentioned viruses continue to expand throughout our nation.
Attachment A: Operations Manual 

Operation Manual PrecisionVision 5

Introduction Page 2

Features Page 2

Flight Modes Page 2-7

GPS Lost, Recovery Page 7,8

Operating Page 9

Pre-Flight Checklists Page 11

Temperatures Page 11,12

Fly Away Prevention Page 13

Takeoff and Landing Page 14

Autonomous Landing Page 16

Throttle Controls Page 17

Transitions Page 18, 19, 20

Data logs and Log viewer Page 20-21

Page 1
Introduction

 This PrecisionVision 5 operator’s manual is not intended to replace or replicate the information 

and training provided to you during the PrecisionVision 5 operators training period. This 

manual is intended as a reference for users who have successfully completed the flight systems 

course. Only trained operators should operate PrecisionVision 5 system and improper 

operation of the PrecisionVision 5 system can cause serious personal and/or property damage. 

This manual, including addendums, is complete and updated as of the date of systems training. 

Features

The PrecisionVision 5 capabilities include airspeed hold, altitude hold, turn coordination, GPS 

navigation as well as autonomous launch and recovery. Extensive data logging and manual 

overrides are also supported, as is a highly functional command buffer. All feedback loop gains 

and flight parameters are user programmable and feedback loops are adjustable in flight. 

• Altitude hold, airspeed hold, and GPS waypoint navigation 

• 1,000 programmable waypoints or commands 

• Powerful command set allows flexibility when describing your mission 

• Fully integrated—all sensors required for complete airframe stabilization are integrated into 

a single circuit board 

• Controls up to 24 servos or relays 

• Complete autonomous operation from launch to recovery 

• Supports manually directed and autonomous flight modes, as well as an integrated RC 

override 

• Extensive data log capability simplifies post flight diagnostics and analysis 

• Integrated POST (Power On Self-Test) ensures reliability and repeatability 

• Low battery warnings, both on the ground and in flight 

• User programmable error handlers for loss of GPS signal, loss of RC signal, engine failure, 

loss of data link, and low battery voltage 

• Extremely low 24-gram weight 

• Feedback loop gains are adjustable while in flight 

• Easy to use setup wizard simplifies system integration 

Helicopter Flight Control Modes 

The autopilot can control a helicopter in several modes.

Page 2
Pilot in Control (PIC) 

PIC mode allows the pilot to control the helicopter manually. This is normally with a Radio 

Control system (RC); this is similar to normal radio control, but all the mixing is performed by 

the autopilot. Alternatively, GCS-PIC allows control from the Ground Control Station (GCS), for 

example using the Joystick controller. 

Computer in Control (CIC) 

CIC mode gives control of the helicopter to the flight computer. There are three main subsets 

of CIC mode. UAV Mode gives all control of the helicopter to the autopilot; your helicopter 

follows a flight plan stored on board the flight computer. You can modify this flight plan at any 

time from the GCS. 

Arcade Modes are a set of hybrid control modes, which allow a pilot to control a helicopter’s 

higher level behavior without having to actually fly the helicopter. The autopilot stabilizes the 

helicopter and manages the helicopter’s flight controls based on the higher level inputs 

provided by the pilot. There are three main CIC arcade modes. 

• CIC Attitude Arcade 

• CIC Position Arcade 

• CIC Velocity Arcade 

In arcade modes, the stick inputs command either a rate of change proportional to the stick 

deflection or an absolute position. For example, when flying in CIC Attitude arcade mode, the 

rudder stick commands a rate of change of desired heading, the aileron stick commands a 

desired roll angle, and the elevator stick commands a desired pitch angle. In each of the three 

CIC Arcade modes, the pilot may control throttle/collective pitch manually to control altitude. 

Alternatively, a fourth arcade mode, the pilot then adjusts the desired altitude by using the 

‘throttle’ stick altitude Hold, may be enabled; and the autopilot will manage the throttle to 

maintain altitude as set by the pilot. All of the CIC arcade modes can be controlled by the RC 

transmitter’s joysticks. Also, a PC joystick device connected to the GCS may be used for all 

arcade modes except Altitude Arcade mode. RPV mode is similar to the CIC arcade modes, in 

that a pilot directs the desired behavior while the autopilot controls the helicopter to achieve 

that behavior. However, when in RPV mode, the autopilot flies the helicopter and the pilot 

commands changes in desired Speed, Altitude, and Heading from the GCS computer, using GCS

or the Joystick controller. No RC transmitter is used for this.

About Flight Control Modes 

This chapter explains how to control the autopilot in flight, which includes: 

• Explanations of the control algorithms used while hovering, flying forwards, and turning 

in flight in CIC (Computer in Control) mode, and the PID loops that are active in each 

case

Page 3
• A description of the various CIC arcade modes, which fly the helicopter using a 

combination of pilot input and autopilot feedback control, and the PID loops active for 

each mode 

• The algorithms used to control flight when dealing with a loss of GPS signal or low GPS 

signal strength 

• Controlling the autopilot via the ground control station PC using RPV (Remote Piloted 

Vehicle) mode 

Flying Through

Once it has established a hover at the waypoint, the autopilot turns the helicopter to face the 

next waypoint and then flies forward in a straight line towards the waypoint. 

When field (Fly through Waypoints in GCS): 

Hoverat commands will cause the helicopter to stop and hover at the waypoint. Flyto 

commands in the fly file will cause the helicopter to fly through the waypoints. Once the UAV

reaches a waypoint, instead of stopping, the UAV executes an in-flight turn towards the next 

waypoint. In-flight turns are used by the helicopter also when the destination waypoint 

changes during forward flight. The UAV will execute an in-flight turn when a waypoint is moved 

on the GCS map and also when... 

• Entering/exiting a pattern 

• Entering/exiting RPV mode 

• Regaining GPS lock after losing the GPS signal 

• Moving a pattern origin

Be aware that large velocities combined with the desired velocity slew limit and velocity gains 

can lead to overshooting a waypoint.

There are three state fields used by the autopilot to control turning in-flight as well as flying 

through waypoints. Their description provides the basic logic, which determines whether the 

helicopter is hovering in straight-line forward flight, or executing an in-flight turn, and thus 

which control strategy is used: 

• [heliFwdFlight], is set to ‘1’ when the helicopter is in forward flight and is set to ‘0’ when 

it is in a stationary hover. The autopilot sets this field based on the command being 

executed (for example. starting or completing a flyto command) and also based on the 

desired forward speed in RPV mode. The value of this field is checked when the 

helicopter must turn in order to determine if the turn will be in-place while hovering, or 

if it will be an in-flight turn. 

Page 4
• [heliWptChanged], is set to 1 by the autopilot when it detects that a waypoint has 

changed. A waypoint changes when the autopilot starts flying towards a new waypoint, 

or when the target waypoint is modified while [heliFwdFlight] indicates the HELI is in 

forward flight. The field [heliWptChanged] value is set back to ‘0’, when the helicopter 

has finished turning and is flying along a straight track towards the next waypoint. 

• [heliStopAtNextWpt], determines whether or not the autopilot will stop at the next 

waypoint. When [heliNavigationType] =1, the autopilot stops at each waypoint anyway, 

so [heliStopAtNextWpt] is ignored. The field value is set to ‘1’ or ‘0’ at the beginning of 

a new navigation command, based on the type of command. A flyTo command sets 

[heliStopAtNextWpt] value to ‘0’. A hoverAt command and the portion of the circuit 

command that flies towards the landing location sets [heliStopAtNextWpt] to ‘1’. As the 

autopilot flies towards a waypoint while turning, the track is constantly being 

recalculated from the current point to the destination waypoint to give a track heading. 

The desired heading changes at the configured slew rate until it matches the track 

heading. Once the desired heading matches the track heading, the in-flight turn is 

completed, and the autopilot maintains desired heading equal to the track from its 

current location to the destination waypoint. During the turn, the Roll from Crosstrack 

Velocity loop is set to maintain a zero Y-velocity. The desired X-velocity is kept constant 

from the start of the in-flight turn until the turn has completed. 

CIC Arcade Modes

The various CIC arcade modes allow the pilot to manually direct the helicopter’s flight at a high 

level, while the autopilot maintains stability of the helicopter. Though you might be directing 

the helicopter, remember that the helicopter is still being controlled by the autopilot in CIC 

mode at this stage, and these modes are called CIC Arcade modes. 

There are four CIC Arcade modes that may be selected on the autopilot. 

CIC Attitude Arcade Mode 

In CIC Attitude arcade mode, the pilot has direct control of the helicopter’s desired attitude–

desired pitch angle, desired roll angle and desired heading – via the RC transmitter or a joystick 

connected to the GCS. The throttle/collective is controlled by the transmitter throttle stick or a

joystick connected to the GCS. When flying in CIC Attitude arcade mode, the value of desired 

pitch (Longitudinal cyclic) is controlled by the elevator channel on your transmitter and varies 

between positive and negative 40°. The value of desired roll (Lateral cyclic) is controlled by the 

aileron channel and also varies between positive and negative 40°. 

• If the stick is centered, then both desired roll and desired pitch will be 0° 

• Full forward stick results in a desired pitch of negative 40° 

Page 5
• Full back stick results in a desired pitch of positive 40° 

• Full right stick results in a desired roll of positive 40° 

• Full left stick results in a desired roll of negative 40° 

Note that this assumes that your elevator and aileron channels are generating pulses in the full 

one to two millisecond range as per the requirement indicated in the Autopilot Configuration 

Wizard. If the end points of your transmitter have been reduced, then the range of desired 

pitch and roll will also be reduced. 

It is a good idea to setup some sensors on the GCS to view desired pitch, desired roll, and 

desired heading.

This will allow you to familiarize yourself with the operation of the autopilot in arcade mode 

while the helicopter is still on the ground. 

You may also find it useful to add sensors that display current pitch, roll and compass heading.

Since the rudder channel controls desired heading it is important that any external gyro is 

disabled when the autopilot is in both CIC mode and arcade mode. 

If possible, set your gyro so that it is enabled in PIC mode and disabled in CIC mode using the 

same channel on your RC transmitter/receiver that you use to switch the autopilot between PIC 

and CIC mode. S

CIC Position Arcade Mode

The autopilot holds current position at an imaginary waypoint while the control stick is 

centered. When the elevator/aileron stick of the transmitter is moved away from center, the 

stick deflection sets the desired velocity in that direction. The helicopter moves until you 

release the stick; then the autopilot slows down and adjusts position to hold at that position 

where the stick was centered. 

For example, moving the ‘Elevator’ stick forward switches the autopilot to velocity arcade 

mode and accelerates at the configured slew rate until it reaches the velocity commanded by 

the stick position. The helicopter will continue to move until you center the stick, then the 

helicopter slows down at the configured slew rate and adjusts position until it is holding at the 

point where you released the stick. 

When moving position at higher speeds, for better stopping accuracy it is wise to reduce the 

stick deflection as you approach the new position, so the helicopter arrives at the new position 

slowly; this will avoid overshoots. 

Page 6
CIC Velocity Arcade Mode

The autopilot commands a velocity in the front/back direction (X) or side to side direction (Y) 

proportional to the control stick deflection. The throttle/collective is controlled by the 

transmitter throttle stick or a joystick connected to GCS. 

NOTE: Velocity Arcade is used in part of Position Arcade mode but we do NOT recommend 

using this mode on its own; trying to hover in Velocity Arcade mode can lead to pilot-induced 

oscillations. 

CIC Altitude Arcade mode 

CIC Altitude Arcade mode may be combined with any one of the other arcade modes, so 

providing automatic altitude hold. The desired altitude may then be changed by moving the 

throttle control stick up or down from center. Centre position holds the currently set altitude. 

For all CIC Arcade modes when Altitude Hold Arcade is turned off, the throttle control stick 

adjusts the input throttle linearly, and translates to the power and collective throttles using the 

TLUs (Table Look-Ups)

All Arcade Modes 

In all arcade modes desired heading is set by the transmitter’s rudder stick. Be aware that 

there is a small dead-band around the center of each of the transmitter’s stick in all arcade 

modes except Attitude arcade. 

Helicopter Control when GPS is Lost 

When GPS is lost on a fixed wing plane, it can no longer navigate to specific locations unless 

dead reckoning is enabled. It can however level its wings and continue in a straight line until 

GPS is regained, or even hold a constant angle of roll and fly in an approximate circle so it does 

not fly too far away from its original location, in case of an extended GPS loss. A helicopter 

requires constant corrections in pitch and roll in order to stay at the same location, or continue 

to fly in a straight line or circle. When GPS is lost, the filter continues to estimate the position 

and velocity based on the accelerometers. However, without corrections from the GPS, the 

estimates will quickly diverge from the actual values. GPS loss impairs the controllability of a 

helicopter. Without the knowledge of the helicopter’s location and velocity, it is impossible for 

the autopilot to know what pitch and roll corrections must be applied in order to navigate or to 

hover. In order to cope with losing GPS, the autopilot constantly takes an average of the 

desired pitch and roll values when GPS is available, and sets the desired pitch and roll to the 

recorded values if GPS is lost. This strategy assumes that the average desired pitch and roll will 

be close to the values that will keep the helicopter stable. 

Page 7
GPS Loss- Recovery Method 

In addition, autopilot has the ability to allow the operator to control the desired pitch and roll 

during a GPS loss. If the operator cannot take control of the helicopter using an RC transmitter, 

the operator can use this feature to keep the helicopter stable until GPS is regained. It is best to 

have visual contact with the helicopter so that you can tell what desired pitch and roll 

corrections are necessary to keep the helicopter stationary, since the position of the helicopter 

on the map will not be updated when GPS is lost. If you cannot maintain visual contact with 

the helicopter, you can try to keep the artificial horizon in a level attitude. However, the 

helicopter could be in a level attitude and still have a high velocity due to wind or being out of 

trim. If you wish the operator to be able to control the helicopter’s attitude when GPS is lost, 

tick the “Popup roll control window when GPS failure is detected” option in the Comm tab of 

the GCS Settings dialog. 

GPS Signal Quality 

Sometimes, even though the GPS receiver is still generating fixes, the quality of the GPS signal 

degrades significantly for a brief period of time, causing the helicopter to suddenly go off-track, 

for no apparent reason. For numerous reasons, the GPS sometimes sends a few fixes in a row 

that have, for example, a very high velocity, or a position that suddenly jumps many meters 

away, when the helicopter is actually hovering in the same place. [GPS_ACCURACY_SPD], gives 

the estimate, from the GPS receiver, of the level of error in the velocity fixes that the GPS 

receiver is reporting. The larger the number is, the larger the estimated error in the GPS 

velocity, which correlates to the error in the GPS position. 

The filter estimates the helicopter’s position and velocity. It uses the value of the field 

[GPS_ACCURACY_SPD] to mitigate the effects of a temporary reduction in GPS signal quality. It 

does so by reducing the weight the filter gives to the GPS position and velocity data when 

estimating the position and velocity despite reducing the effect on the helicopter’s 

performance, it is impossible to completely eliminate the navigation errors caused by 

erroneous GPS fixes. Adding to your datalog will allow you to check if any navigation errors 

that you noticed during a flight can be ascribed to a loss in GPS quality, so that the possibility of 

other causes can be eliminated. An additional cause of reduced GPS signal quality occurs when 

a GPS receiver switches out of differential GPS (DGPS) mode. If you are sending corrections 

from a base station to the GPS receiver on your autopilot, and there is a sudden loss in the 

DGPS signal, the GPS receiver times out and stops using the out-of-date corrections and 

sometimes outputs a sudden “jump” in the position recorded in the position fixes 

Page 8
RPV Mode 

Remote Piloted Vehicle (RPV) mode is a partially autonomous CIC control mode that allows you 

to set the helicopter’s desired heading, altitude, and speed (forward flight velocity) in the GCS. 

You can switch between RPV mode, and UAV mode by clicking the green UAV button on the left 

side of the GCS screen, or by using the “Change Mode” item in the “Autopilot” menu. The MP 

Joystick Controller may also change to RPV mode. In RPV mode, the helicopter will maintain 

forward flight at the designated altitude, speed and heading; you may change these desired 

values by using the up and down arrows placed above the flight instruments at the bottom 

center of the GCS display or by using a joystick device. If the target speed is set to zero, the 

helicopter will slow down to zero speed and hover where it stops. Behavior when switching 

from UAV/RPV and RPV to UAV upon switching to RPV mode, the current target speed, 

heading, and altitude are maintained until they are changed using by the operator using the 

GCS. When switching out of RPV mode, the helicopter will resume the command it was 

executing in its fly file before switching to the RPV mode. If the target speed is zero the 

helicopter will simply turn to the next waypoint and hover; if target speed is more than zero, it 

will turn to reach the next waypoint while flying forward. 

Operating 

This chapter introduces you to the basic operation of your PrecisonVision 5, from power on, 

through pre-flight checks to take off and land. It describes the use of GCS (Ground Control 

Station) with your autopilot and also describes any fatal error messages that you may see 

during operation. The effects of temperature on your autopilot are then discussed and finally 

there is a basic guide on downloading a data log from your autopilot after a flight. 

Page 9
Power on 

When you apply power to your PrecisonVision 5 the autopilot starts an initialization process, 

loading the firmware into memory and then running it. You can monitor initialization by

connecting to your PrecisonVision 5 using a text terminal program; if you have a custom LCD 

display you may use that too. 

The autopilot will turn on two LEDs as the program loads then one turns off, leaving the power 

indicator LED on. A series of dots appears in a terminal program as the firmware is decrypted, 

finishing with the message ‘DONE!”; now the firmware runs and the startup report appears. 

The autopilot then zeroes sensors and waits for the GPS to lock. In a terminal program you will 

then see status information that consists of both servo and main battery voltages along with 

GPS status and any error messages. 

Once the GPS has locked and the gyros have stabilized, your PrecisonVision 5 will print the zero 

values of the various sensors. In the GCS, the READY panel will turn green.

Until your PrecisonVision 5 has finished its initialization, it will not allow you to switch between 

RC mode and CIC (computer in command) mode using channel 5 on your transmitter, but 

rather will leave all servos in their neutral position. Other GCS reports will also not provide 

data until initialization has completed. 

Faking GPS Lock

This feature is handy if you are working on your PrecisonVision 5 inside where there is no GPS 

signal or if either the GPS receiver or GPS antenna are disconnected. Note: You cannot fly with 

Faked GPS! 

To initialize your PrecisonVision 5 without waiting for the GPS receiver to lock, press the “f” key 

(for ‘Fake’) four times while running GCS, or double click the GPS box on the status bar at the 

bottom of the GCS window. 

If GCS is running, your PrecisonVision 5 will print a message acknowledging that it is no longer 

waiting for the GPS to lock. On the GCS, the GPS status panel will turn yellow. This is in effect 

only until your PrecisonVision 5 is powered down. The next time your PrecisonVision 5 is 

initialized it will wait for the GPS to lock as normal. 

Page 10
Fake GPS Behavior

When you fake a GPS lock the GPS position data is ‘faked’ with these rules: 

• If a current position is available from the GPS receiver (i.e. the receiver has previously 

locked and stored the last known position) the autopilot will use this position. 

• If no position is available, it will search the loaded fly file for an absolute waypoint and 

lock onto it. (Note: the waypoint in pattern 15 for the GoTo plug-in does not count) 

• If no position is found it will then lock to 0E, 0N. 

Once the GPS has been faked, the real GPS position will no longer be read from the receiver. 

The GPS data will no longer change—the velocity will always be zero, the altitude will always be 

0, and the GPS time will remain zero. This happens for all GPS types, including a user-defined 

one. Other Effects of Fake GPS 

• The geofence check will never result in a fence violation because the check Fence

Violation assumes the UAV can’t fly with a faked GPS. 

• The read gps function just generates the same GPS position over and over with all 0’s

• With PrecisonVision5, the Check HeliTakeoffErr function will not trigger an error if the 

world velocity in any direction exceeds 5 ft/s because the world velocity is not 

considered accurate without a GPS. 

• In the firmware, the filter isn’t given any GPS data. All 0’s are passed into the filter. 

• In the firmware, all body x/y velocities and hover x/y offsets are set to 0 (unless using an 

external position guide which provides velocity information)

Preflight Checks

Generally, you should initialize your PrecisionVision 5 in the direction of takeoff as well as at 

the position where you intend to takeoff. Moving the aircraft to the takeoff location after the 

autopilot is initialized can generate an incorrect location and heading.

Cold/Warm Soak

If you take your UAV from a building or vehicle to the outside where the temperature is quite 

different, you should leave your UAV to ‘soak’ in the new temperature before turning power 

on, to allow sensors to acclimate to the temperature.

If you do not do this, you may sometimes get the fatal error "Difference between accl 

temperatures is too large."

Page 11
The actual time you leave the UAV to soak depends upon the vehicle and the temperature 

change; fifteen minutes is a general guide but more time may be required for larger or more 

enclosed UAVs.

Such temperature differences are more likely to happen when outside temperatures are very 

cold but could also occur when moving from air conditioned space to a hot outside.

If you begin to experience such problems due to temperature changes you can try a pre-start of 

the autopilot on-site with GCS connected; like this, you can monitor raw temperature changes 

until the value becomes stable. Cycle the power for normal pre-flight tests.

In cold temperatures, ensure you have “cold-soaked” the UAV, as described above, before 

initializing. Once the initialization is complete, your PrecisonVision 5 is ready to fly. The READY 

panel in the GCS will be green and there should be no red warning messages. Before initiating a 

takeoff, perform the following preflight checks: 

1. In CIC (Computer in Control) mode, rotate the PrecisonVision 5 about its pitch, roll axis. 

Check that the elevator, ailerons and rudder move in the correct direction to 

compensate for these rotations. 

2. Make sure that the RC status panel in GCS indicates RC-PIC (Pilot in Control) in red.

3. Check that the battery voltages are acceptable (fully charged 59.4 volts). 

4. Check that the airspeed indicator is connected. Press your finger firmly on the pilot tube 

and verify that the airspeed value increases. 

5. Make sure that any LCD/Portable is disconnected and that all flight equipment is clear. 

6. Switch to PIC mode and confirm all controls respond correctly and that the RC status 

panel in GCS indicates RCON in green. 

7. Check that the engine does not stop running at idle and that the engine runs properly at 

full throttle. For electric drive, make sure that full power is available when you set full 

throttle and the motor stops when you command it. 

8. Perform a vibration test by putting your PrecisonVision 5 in CIC mode and advancing the 

throttle slowly to full. Verify that the elevator and rudder do not move significantly. 

Note that in CIC mode you can set full throttle either by initiating Takeoff or by first 

setting manual throttle override in the autopilot. If you have GCS connected, another 

good vibration check is to set PIC mode and slowly advance throttle to full and back to 

idle. Verify that the artificial horizon is stable during this check. 

9. Check that the elevator, ailerons and rudder are approximately in their neutral position 

in CIC mode. 

10. Check that wind speed does not exceed 50% of cruise speed. 

11. Turn off the RC transmitter and verify that your PrecisionVision 5 switches to CIC mode 

and the RC status panel in GCS indicates RCOFF in green. 

Page 12
Note: if you flash a flight file to your autopilot after it has initialized, you should cycle 

power and allow your autopilot to initialize again. This ensures all pattern locations are 

initialized correctly according to the new flight file. 

Temperature Effects 

Most of the sensors in your PrecisionVision 5 are sensitive to large changes in temperature 

therefore allow your PrecisionVision 5 time to adjust to large changes in temperature. For 

example, if your PrecisionVision 5 is brought outdoors from a warm building or car, allow ten to 

fifteen minutes for the sensors to cool/warm to the outdoor temperature. The airspeed 

transducer zero may require re-calibration if it was calibrated at a temperature that is different 

from its operating temperature.

Fly Away Prevention Measures 

Before you fly your UAV we strongly recommend that you put measures in place to prevent 

your UAV from flying away if something goes wrong. Ensure the fly file loaded on your 

autopilot has failure patterns defined for loss of RC, loss of GCS link, loss of GPS and any other 

appropriate events. You should also consider such steps as these when planning for safety 

before any flight: 

• Set up a GeoFence in the .vrs at the most extreme boundaries in which you can fly 

safely; this will stop the engine and force the UAV to descend if it passes the boundaries 

you have set up. (Note the geofence action will be effective in PIC also!) 

• Set up a maximum waypoint distance warning in your .vrs; this sets a limit which will 

trigger a fatal error if your autopilot initializes with a fly file containing any waypoint 

further than this distance. 

• Create an overlay for your test flying area map, using the GCS Map Selector tool. 

Configure an outer no-fly zone and an inner warning zone to allow your GCS operator to 

see when the UAV reaches the limits of your safe operating area and to take action. 

• Plan and discuss safety procedures with your safety pilot GCS operator so they can 

detect a problem early and know what action to take if the UAV should begin to fly 

away. If the UAV flies into the warning zone your RC pilot must take control and fly the 

UAV out of the warning zone. If the UAV flies into the no fly (red) zone the procedure 

must be to stop the engine and terminate the flight. 

• Use a thread in your .fly file, activated by a payload button, to stop the engine manually 

if necessary. Do not use a pattern for this; a user-defined pattern may not operate if 

another pattern, especially a failure pattern, is already active. 

It is better to be prepared and take action early than wait until it is too late.

Page 13
Takeoff and Landing

When the autopilot has passed all the preflight checks you can start a flight by initiating either a 

manual or an autonomous takeoff. Always initialize the autopilot at the location and in the 

direction in which you will be taking off. Moving the aircraft to the takeoff location after the 

autopilot is initialized can generate an incorrect location and heading

Takeoff Caution– before proceeding, please note: If you take off from the ground in PIC mode 

without Throttle Override turned ON, you MUST NOT switch to CIC in the air. Upon switching 

to CIC, the helicopter's throttle will immediately drop to zero because the throttle from altitude 

PID loop is only initialized when the takeoff command is run in CIC mode. If the takeoff is 

performed in PIC, there is no reliable way for the autopilot to recognize when the helicopter is 

off the ground and initialize the throttle from altitude PID loop. This is because AGL readings 

indicating the autopilot is ‘off ground’ could be generated by lifting the helicopter, and an RC 

transmitter throttle value above the heliMinHoverThrottle threshold value could be applied 

while the speed controller is physically disconnected or the engine is stopped. 

Details

An explanation of the takeoff command: If the off-ground state becomes active before you 

press takeoff, then the takeoff command will exit without starting the throttle-from-altitude 

loop. This means any subsequent switch into CIC will drop the throttle to zero. So long as you 

press arm and takeoff before the off-ground state becomes set, then the takeoff command will 

ramp up the CIC throttle as if it was actually controlling the throttle, and will switch on the 

throttle-from-altitude loop when the takeoff command terminates. The current “best practice” 

is to always press Arm and Takeoff in the GCS before liftoff in PIC, even if you don’t intend to 

ever transition to CIC or have throttle override enabled, with one caveat mentioned below. 

This is because even if you don’t intend to switch into a mode where the RC transmitter does 

not control the throttle, if an RC glitch occurs the throttle is no longer controlled by the RC and 

therefore the throttle is set to the output of the throttle loop. If the loop is not engaged the 

throttle will drop to zero, thus it would be beneficial to have the throttle loop engaged as a 

backup. The caveat is that if you lose RC control and don’t have the ability to control the heli 

via the GCS then you may have no way to kill the engine – in some cases, the preferred failure 

mode may be to crash into the ground instead of to unpredictably fly around under power but 

without control. This is relevant even more so if the autonomous loops have never been tuned. 

Another option in this situation may be to set the throttle to ‘throttle fixed’ with a small but 

non-zero throttle value, so that the failsafe throttle value will not be high enough to keep the 

heli aloft forever, but perhaps would ensure a somewhat softer landing. 

Page 14
Heli Status Monitor 

In the latest GCS version, the Heli Status Monitor should always be run before and during flight. 

The Heli Status Monitor will check your autopilot configuration and warn you about the throttle 

loop not being engaged. As soon as you start up the Heli Status Monitor, it will give a warning 

that the throttle is not engaged and remind you to press arm/takeoff before going off-ground. 

Once you’re in the takeoff command and you’ve pressed arm and takeoff, and/or if the throttle 

loop is engaged, the warning goes away. If you transition to off-ground while the throttle loop 

is not engaged, then the warning becomes an error and starts blinking and making noise. The 

sound can be disabled via a button if you’re doing ground tests and have the throttle physically 

disconnected. Also note that if the Throttle from Altitude PID loop initializes in PIC while the 

helicopter is not actually in the air, the throttle would jump up instantly upon a switch to CIC, 

creating a potentially dangerous situation. If you require the ability to take off in PIC and 

switch to CIC in air, you must have the Throttle Override field turned ON. 

Autonomous Takeoff 

The autopilot follows a specific internal procedure when commanded to perform an 

Autonomous Takeoff. The CIC Autonomous Takeoffs should not be attempted until ALL loops 

have been tuned to provide safe, stable and reliable flight.

The Takeoff command 

An autonomous takeoff is performed using the takeoff command. When the takeoff command 

begins, the throttle increases smoothly until the autopilot detects the ‘off ground’ state. This 

terminates the takeoff command and activates the next command in the fly file. The following 

description of the takeoff states gives more detail of these Sequence criteria and the takeoff 

steps.

Throttle Control during Takeoff 

1. Once you press the takeoff button in the GCS and the takeoff begins, the throttle 

increases at a constant rate set by [heliTakeoffThrottleRate]. This value is in units of 

fine servo per fifth of a second. 

2. If [heliTakeoffThrottleHold] is not zero, then the throttle will stop increasing once it 

reaches the value held in this field if the field has the value zero, then steps 3 and 4 are 

skipped and the throttle continues to increase. This field should be set to a value high 

enough that the helicopter rotor head has stabilized and ceased wobbling. 

3. In order to allow the helicopter to stabilize, the autopilot will hold the throttle constant 

for the amount of time specified in the [heliTakeoffThrottleHoldTime]. This hold time is 

required as many helicopters wobble as the rotor-blades start to spin and only stabilize 

once the blades are near operating RPM. 

Page 15
This wobble can affect the autopilot in two ways: 

a. It can result in large vibrations causing errors in the attitude estimate 

b. The autopilot may generate an error as it interprets this wobble as excess 

vibration caused by some mechanical failure. 

The hold time allows any wobble induced vibrations to dissipate and allows the autopilot time 

to correct any attitude errors that may have accumulated due to the wobble. If you notice 

attitude errors just before takeoff or the pilot generates a Sensor error on heli takeoff, then you 

may have to increase either [heliTakeoffThrottleHold] field or the 

[heliTakeoffThrottleHoldTime], or investigate and rectify the cause of the vibrations 

4. Once the hold time has elapsed the autopilot will begin to check for a sensor error. The 

throttle will remain constant for three more seconds while the autopilot checks for 

vibration induced sensor errors. Note that this is an important check as normal wear on 

a helicopter can cause an increase in vibrations to the point where they become 

unacceptable 

5. The throttle will then stay constant for another 3 seconds, while the sensor check is 

performed; then, as long as no errors are flagged, the throttle starts increasing at a 

constant rate set by [heliTakeoffThrottleFastRate]. This value is in units of fine servo 

per fifth of a second. If this field is 0 the rate used is the same as field 924. 

6. If there is an AGL sensor installed, the takeoff command will terminate once the 

helicopter is higher than the value specified in [hoverGndToAirAlt], above the ground. If 

there is no AGL installed, the takeoff command will terminate once the throttle reaches 

the value specified in [heliMinHoverThrottle]. Note that the throttle will not increase 

past [takeoffThrottle], even if the helicopter has not lifted off the ground yet. 

7. After state 5 is reached, the throttle increases for an additional second before the 

takeoff command ends and the next command in the fly file is executed. This additional 

throttle helps the helicopter to climb out of ground effect 

Autonomous Landing 

An autonomous landing is initiated when the circuit command is reached in the fly file. In order 

for autonomous landing to work, the autopilot can use data from AGL height, throttle position 

or landing gear switches. Depending on your helicopter type, size and weight you will have to 

choose one of these methods. The preferred method by default is to use both the AGL device 

AND throttle position; in this method the autopilot requires both values to be below configured 

threshold values before it decides it has landed. To use the AGL device, [aglMode] must be set 

to 1-DEM or 2DEM Pitch/Roll. In the absence of a non-zero value, the desired descent rate will 

be set to 0.625 feet/s until it reaches the ground, and will then turn off the throttle 

Page 16
Circuit Command 

The circuit command is similar to that is used in a fixed wing aircraft – although the altitude 

offset parameter is ignored at this time and must be 0. Circuit (waypoint), takeOffAgain, 

altitudeOffset must be 0}. The helicopter flies directly to the landing point using the same 

sequence of steps as defined in the hoverAt command. The landing altitude parameter is 

ignored at this point in time so the helicopter will descend in the circuit command expecting 

the landing altitude to be the same as the takeoff altitude. The pressure altitude may drift due 

to temperature or air pressure changes to make it too inaccurate to use for landing. Instead, 

once the helicopter reaches the waypoint it will descend at a fixed rate, checking for the AGL to 

start producing reliable readings. Once the AGL starts receiving reliable readings and they are 

lower than the AGL switch altitude, [aglSwitchAlt] , the helicopter will descend at a slower rate, 

determined by the altitude and the settings. Landing States are valid when the AGL is enabled 

and the value [aglMode] is set to non-zero.

Fly to landing point

Fly to the landing point specified by the command parameters, or runway fields, and move on 

to the next state when the flyTo command terminates. 

Descend

Desired Z Velocity is set to the descent rate in [heliCctDescentRate]. Alternatively, if the old 

altitude hold mode is being used, decrease the desired altitude at the rate specified in 

[heliCctDescentRate]. Do not decrease the desired altitude more than 25 x 

[heliCctDescentRate] below the current altitude so as to ensure that a large P and I term does 

not build up in the throttle from altitude PID loop due to the current altitude lagging behind the 

desired altitude. Monitor the AGL, and if readings are consistently below the [aglSwitch Alt) for 

1.5 seconds, then switch to the “Descend with AGL” state. 

Descend with AGL 

Desired Z Velocity is set to the lowest of either the descent rate in [heliCctSlowDescentRate] or 

the altitude AGL x ‘Desired body Z velocity gain from altitude error’ (field 971). Alternatively, if 

the old altitude hold mode is being used, decrease the desired altitude at the rate specified in 

[heliCctSlowDescentRate]. Monitor the AGL, and if it stops giving readings for 1.5 seconds, 

then switch back to the “Descend” state, in case the readings that triggered switching to this 

state were spurious, or if the helicopter’s altitude increases past the AGL threshold again. 

Continue until altitude reaches [heliCctLandAltitude]. 

Page 17
Reduce throttle

Decrease the throttle at the slow rate specified in the [heliLandThrottleRate] until altitude 

reaches [hoverAirToGndAlt].

Cut throttle 

Decrease the throttle at the fast rate specified in [heliLandThrottleFastRate]. If that rate is 

zero, then cut the throttle at the slow rate. Once throttle is less than

[heliMinHoverThrottleGnd] AND the AGL altitude is still less than [hoverAirToGndAlt] cut the 

throttle to zero and transition to the “Done” state. If no AGL device is enabled, the only 

criterion for completing the landing is when throttle is less than [heliMinHoverThrottleGnd]; 

the circuit command then cuts the throttle to zero and transitions to the ‘Done’ state. If 

landing Switches have been configured, then once the switch state indicates ON ground, the 

circuit command cuts the throttle to zero and transitions to the ‘Done’ state. 

Circuit Complete

The helicopter has completed the landing. The autopilot will remain in the circuit command 

indefinitely or until it is moved to a new command manually by a command from the GCS. 

 

Manual Engine Cut Control 

CAUTION – Avoid High Descent Rates near ground. Note that as a helicopter descends it can 

suffer from the ‘Vortex ring effect’. This state occurs when your descent rate is too fast and 

there is little or no wind; it results from the downwash of the rotor not being blown away. The 

turbulence from the vortex ring can result in the helicopter being unable to generate sufficient 

lift to stop the descent. The vortex ring effect can occur at any height but of course is much 

more serious closer to the ground. The effect is usually only a problem in hover descents; while 

the helicopter is flying forwards it is moving away from the downwash all the time. To avoid 

this state, it is best to limit your descent rate when hovering.

Page 18
Control Mode Transitions 

The autopilot can be switched from one control mode to another during flight. This section 

describes facts that you should be aware of when you command a change in control mode On / 

Off the ground. The hover pitch/roll from velocity feedback loops are always on, when the 

helicopter is grounded. While on the ground:

• The desired body x/y velocity is 0 

• The hover waypoint is held to the current location 

• The desired heading is continually set to the current compass heading. 

• The I-terms of the inner loops are turned off 

Ground to Air Transition 

The autopilot will switch from ground to air mode (Off Ground) when at least one of these 

conditions is met: 

a. If heliThrottle > heliMinHoverThrottle (field ID 775) 

b. If an AGL sensor is used, and the AGL altitude is more than hoverGndToAirAlt 

Upon switching from ground to air, the I-terms are enabled for Hover rudder from heading, 

Elevator from pitch, Aileron from roll, the Hover roll/pitch, and Throttle from Altitude (if in use) 

loops 

Air to Ground Transition 

The autopilot will switch from air to On Ground state when BOTH of these conditions are met: 

• When the heliThrottle setting becomes less than the minimum throttle. The minimum 

throttle setting is determined by [heliMinHoverThrottleGnd]; if this field is 0, then the 

minimum throttle is the same as the ground to air threshold, heliMinHoverThrottle. 

• If an AGL sensor is used, the AGL altitude must be less than hoverAirToGndAlt for 2 

seconds.

Configuring the Transition Thresholds 

Configuring these thresholds is critical because if they are not set properly, the I-terms may 

wind up while the helicopter is on the ground, or the helicopter may get far off the ground and

still have the control loops disabled! Note the transition throttle values are relative to 

heliThrottle and NOT the throttle output seen in the GCS. You can record heliThrottle in the 

datalog while flying manually to discover the throttle values you need for transitions and cruise 

speed etc. The autopilot enables the feedback loop I-terms if either the AGL sensor reaches the 

value set for (hoverGndToAirAlt), or if the (heliMinHoverThrottle) value has been reached by 

the throttle input. This means that when the autopilot is on the ground, it is important that the 

AGL sensor should read several inches less than what is set in field 917. 

Page 19
Set field 775 to the input throttle value just before the known lift off point of your airframe. 

This may require some research to determine the appropriate value. Note that the appropriate 

value will change if the lookup tables for collective pitch and throttle curves are changed or if 

the mass of the helicopter is changed. 

Once the AGL is installed correctly, and field 775 is set with an appropriate value, the autopilot

will turn on the feedback loop I-terms if either the AGL reaches the value set in

(hoverGndToAirAlt), or if the autopilot sees a heli-throttle value that meets or exceed that set 

in field 775. 

Other Transitions 

From RCPIC or CIC Arcade Mode to CIC UAV Mode or from RCPIC to CIC Arcade Mode, while in 

Air 

• The hover waypoint is set to the current location 

• The desired heading is set to the current compass heading 

• The desired altitude is set to the current altitude 

• The Throttle from Altitude loop is set to maintain same throttle 

• The desired altitude is set to the current altitude 

From Any Mode into Position Hold Arcade Mode while ‘In Air’ 

• The hover waypoint is set to the current location 

Switching from Altitude Hold to Attitude Arcade 

To avoid an unexpected drop or rise in the helicopter’s altitude, ensure that your transmitter 

throttle stick is physically positioned close to the normal hovering position before switching 

back to Attitude Arcade, from any of the Altitude Arcade, Velocity Altitude Arcade, or Position 

Altitude Arcade modes. Be ready to react in case of any sudden jumps in altitude

Datalog

It is important to download a data log after each flight, especially when first using your 

PrecisionVision 5. The data log is an important tool for resolving problems. You should also 

keep the matching .vrs file and .fly file that was used for each data log. 

Page 20
Logviewer

You download the datalog from your PrecisionVision 5 by using the Logviewer tool. Logviewer 

is a comprehensive program that both downloads the datalog from your autopilot and also 

displays the datalog in table form and graphically, for analysis. 

Basic points to remember are: 

• The datalog remains intact in your autopilot until the GPS locks again ready for a new 

flight. So after flight and turning power off, leave the autopilot turned off until the 

Logviewer is ready to receive data. 

• Start the Logviewer 

• Tell it to Read a log file from the autopilot. 

• Select Download Options when prompted 

• Turn on power to your autopilot when prompted 

• Normally the Logviewer will make contact in a few seconds and begin downloading 

data. Once datalog download begins, there is no possibility of the GPS locking and you 

losing the datalog. 

If you have any doubt about the GPS locking and clearing the datalog, you can cover the GPS 

antenna or disconnect it from the autopilot. 

Page 21
Attachment B: Maintenance Manual

Maintenance Schedule and Manual

PrecisionVision 5 by Leading Edge Associates, Inc. USA

Outline Page 1

Introduction, Flight Pre and Post Inspection 2

Maintenance Schedules 3

Adhesives and Lubricants 4

Tools Required 5

Conclusion 6

Introduction

This PrecisionVision 5 UAS Maintenance Schedule and Manual presents the information you 

need to successfully perform the scheduled maintenance and routine inspection on the UAS. 

At all times, please remember:

● Only trained personnel should perform the maintenance on a UAS. 

● Improper or lack of maintenance and inspecons can cause catastrophic failure to the UAS

● The use of proper tools is integral to successful maintenance operaons. Use only the tools 

provided or recommended

● Modifications made on the UAS should be done by trained and experienced personnel. 

The maintenance schedule for the PrecisionVision 5 UAS is focused on insuring proper 

maintenance and routine checks of the UAS with emphasis on problems that are caused by 

normal wear on airframe parts and electric connectors. Flight inspection should be done pre 

and post flights.

Flight Pre and Post Inspection

Getting yourself familiarized with the UAS is very important for spotting any unexpected wear 

or failure of any part. Routinely look over the UAS as much as possible.

● Check all electrical wiring and connectors. Remove the canopy and look for fraying or 

 rubbing of any kind on all wiring. Also, look to see if any connector might be possibly broken 

 or coming out. 

● Check baery connectors for any fraying or break in the connector or wires. Check the 

 batteries for any swelling, dents or punctures. 

● Check all carbon fiber props for cracks or splinters and make sure blades are cleaned

 and free of debris and bugs.

● Check all gearing for excessive wear, broken teeth or debris. This includes motor pinion,

 main and auto rotation black gears, front and rear tail black bevel gears.

Page 22
● Check main and tail rotor head and hubs. Look for any screws that might have started

 backing out and fatigue on any of the metal.

● Check all rod and linkages. This includes all servo linkages, main motor heads, rods 

 and linkages. Look for cracks or excessive wear from general use or debris.

● Check landing gear for cracks, screw backing out of any kind and general wear. Also check 

 carbon fiber boom supports for cracks or splinters.

Maintenance Schedules

Please Refer to Airframe Manual for Proper Installation

25 Hours

Check all Bearings and Blocks and Replace if not Smooth with Rotation 

50 Hours

25 Hour Maintenance

Replace Main Motor Controllers

Check Motor Shafts for Wear Around Bearings and Replace if Necessary

75 Hours

25 & 50 Hour Maintenance

Replace All Batteries and Motor Connectors

100 Hours

25 Hour Maintenance

50 Hour Maintenance

Replace all Black Gears 

Replace all Plastic Linkages and Threaded Metal Balls 

Replace Torque Tube, Radial Bearing and Rubber Cover

200 Hours

100 Hour Maintenance

Replace Main Motors

Replace all Servos

Adhesives and Lubricants

In the figure below are the Adhesives and Lubricants. It is VERY important to not only use the 

products, but use the correct ones for maintaining the UAS. Proper lubrication and adhesives 

are critical to the useful life of all parts on the UAS and safe flight operations.

The Loctite CA is used only when a metal screw, set screw or shaft is screwed or set into plastic.

The Loctite 242 Blue is used on EVERY screw, set screw or threaded ball on the airframe. This is 

done anytime a UAS is taking out of service operation for maintenance or replacement. VERY 

IMPORTANT!
The Loctite 641 is used only when replacing radial bearing. A single drop of the 641 adhesive on 

the outside face of the radial bearing is required before it is installed on the UAS. This will lock 

the bearing into its holder and keep the outside race from spinning.

Tools Required

Having the proper tools is essential for maintaining the UAS. It prevents improper maintenance 

due to stripping of screws, set screws, nuts and bolts. Use hardened steel tips for the metric 

Allen Wrenches. The list below details the tools necessary for maintaining the UAS.

Allen Wrenches:

1.5mm, 2.0mm, 2.5mm and 3.0mm

Nut Drivers

4.0mm, 4.5mm, 5.0mm, 5.5mm and 7.0mm

Screw Drivers

1 Small and 1 Large Phillip Ends

1 Small and 1 Large Straight Ends

Ball Link Pliers

The Ball Link Pliers are used to take the Links off the Balls without damaging them.

Needle Nose Pliers

Used for holding nuts that are not accessible with a nut driver.

Small C-Clip Pliers
Conclusion

Please refer to Airframe Manual for all Maintenance Parts and Assemblies. Leading Edge 

Associates, Inc. cannot emphasis enough how important it is to follow proper routine 

inspections, checklists, maintenance schedules and logging of all flights data. If at any time 

trained personnel are unsure of normal maintenance procedures or any questions that may 

arise, please do not fly the UAS. Call customer support at Leading Edge Associates, Inc. Every 

attempt has been made to include all of the information needed for maintenance excellence of 

the PrecisionVision 5 UAS.