K680-4, K1000-4,

 Zeta FX-61

 Operator’s Manual

 Version 1.0

 Revised 4/15/15

The latest version of this document shall be kept with the PIC at the ground control point.
The K680-4, K1000-4, and Zeta FX-61 Unmanned Aircraft System (UAS) are designed 

to lift compact digital still and video cameras for the purpose of photogrammetry, aerial 

photography and inspection. The aircraft are a fusion of off the shelf equipment, and 

prosumer digital cameras resulting in cost effective and reliable aerial data collection 

platforms that can carry camera payloads up to 8 oz (K680-4 and Zeta FX-61 UAS) or 

24 oz (K1000-4 UAS).

When using the UAS in public or civil operations in the USA, you are required to comply 

with the current regulations of the Federal Aviation Administration (FAA) regarding 

unmanned aircraft. Information related to unmanned aircraft systems is available at 

https://www.faa.gov/uas/. Operators are required to have at least a sport pilot certificate 

and US drivers license. Certificates of Waiver or Authorization (COAs) are required for 

each flight when performing public or civil work.

The UAS must be operated during daylight hours using visual line-of-sight (VLOS) and 

visual flight rules (VFR)

The UAS is not a toy and must be assembled, maintained and operated by qualified

personnel. Rotating propellers can cause severe injuries. Do not transport or handle 

the UA with the battery connected. Keep all body parts away from the propellers when 

the battery is connected.
Recommended Operator Requirements

A minimum crew of two is recommended for operating the UAS. A crew consists of a 

Pilot-in-Command (PIC) and Visual observer (VO). Both PIC and VO should be 

positioned at the takeoff and landing area.

Pilot In Command (PIC)

The PIC is responsible for flight planning and ensuring that the UA will be operating 

within the boundaries of the COA and in weather conditions that permit safe operation. 

The PIC is responsible for safe flight operation in both manual and automatic flight 

modes. In addition to FAA requirements the PIC must meet the training requirements 

below.

Visual Observer (VO)

The VO should be competent to observe a flight for the purpose of assisting the PIC. 

The PIC is responsible for determining the competency of the VO. The VO should be 

capable of assisting the PIC in avoiding air and ground obstacles as well as providing 

ground situational awareness to the PIC. The VO should be able to discern the 

direction and attitude of the aircraft to assist the PIC during flight. It is recommended 

that the VO have flying experience with RC aircraft. Being able to discern the aircraft’s 

distance, orientation and heading is a skill that comes with flying experience. If the PIC 

becomes disoriented or loses sight of the aircraft, the VO should be able to advise the 

PIC appropriately. The VO should be thoroughly familiar with the operation of the 

telemetry system. The VO should report UAS status throughout the flight. Status 

information includes battery capacity remaining, waypoint count and GPS precision. 

The Observer must be positioned next to the PIC to facilitate voice only

communications. The VO is responsible for keeping the immediate landing area clear 

of personnel.

Control Equipment

The UAS is controlled using a Spektrum DX9 Transmitter and triple diversity receiver. 

The Spektrum system operates in the 2.4 GHz band and complies with part 15 of the 

FCC rules. The Spektrum system uses proprietary DSMX modulation and is well 

proven in noisy RF environments.

Flight Modes

The aircraft has 5 operational modes which are summarized below. 

Stabilize
While in stabilize mode the aircraft will self level and hold current yaw heading. While in 

this mode the aircraft can drift horizontally or vertically. The Operator is required to 

manually position the aircraft while in stabilize mode.

Loiter

Multirotor:

While in loiter mode the aircraft will self level and hold current yaw heading. The 

aircraft will also hold position using a fusion of inertial, GPS, and barometric 

sensor data. If the control sticks are moved outside of their “dead band”, which is 

the approximate center position, the aircraft will move at a rate proportional to the 

stick movement. Upon release of the sticks, the aircraft will hold the new 

position, altitude and yaw angle.

Fixed wing:

While in loiter mode the aircraft will self level and maintain current altitude. The

aircraft will circle about a point at a user programmed radius using a fusion of 

inertial, GPS, and barometric sensor data. If the control sticks are moved outside 

of their “dead band”, which is the approximate center position, the aircraft will 

move at a rate proportional to the stick movement. Upon release of the sticks, 

the aircraft will hold the new position.

Auto

While in auto mode the aircraft will fly a pre-programmed path consisting of X,Y and Z 

waypoints. Additional commands such as camera shutter triggers can be programmed 

at specific waypoints or at regular intervals along the flight path.

Return to launch (RTL)

When a RTL command is received the aircraft will rise to the RTL altitude, return to the 

home coordinates and then loiter at the RTL final altitude.

Land

When a land command is received the multirotor aircraft will descend vertically until it 

senses that it has landed. The motors will then be automatically shut down. The fixed

wing UA utilizes operator configured parameters including altitude, airspeed and timers 

to achieve the desired glide slope and flare point for auto landing.
Flight Mode selection

Flight Mode selection may be selected through the RC transmitter or through telemetry 

commands. The following transmitter switch positions are used to select flight modes.

Lowest numbered positions are forward, or away from operator. 

Switch E Switch F Flight Mode

1 1 Stabilize

2 1 Stabilize

1 2 Loiter

2 2 Stabilize

1 3 Auto

2 3 RTL

Flight controller hardware, software and firmware

The UA can be equipped with DJI or 3DR flight controllers. Both control systems 

provide the necessary functionality to support manual and autonomous modes. 
Aircraft Fail Safe Procedures and lost link handling

The Pilot-in-Command (PIC) is responsible for safe operation of the aircraft. The 

following automatic failsafe modes provide additional safety features should contact with 

the aircraft be lost or sub-systems fail.

Radio Failsafe

Radio failsafe will trigger if the aircraft loses the signal from the radio control receiver. 

This mode can occur if the transmitter fails or is turned off, the aircraft travels outside 

the range of the RC system, or the connection between the receiver and flight controller 

fails. Radio failsafe will initiate a Return-to-Launch (RTL) if the aircraft has GPS lock 

and is more than 2 meters from the home position.

Radio failsafe will initiate a LAND command if there is no GPS lock or the aircraft is 

within 2 meters from the home position.

Battery Failsafe

Battery failsafe will trigger if the battery voltage drops below a preset voltage for more 

than 10 seconds. Battery failsafe will initiate a Return-to-Launch (RTL) if the aircraft 

has GPS lock and is more than 2 meters from the home position.

Battery failsafe will initiate a LAND command if there is no GPS lock or the aircraft is 

within 2 meters from the home position.

GPS Failsafe

GPS failsafe will trigger if the aircraft experiences a GPS glitch for 5 seconds while in a 

mode that requires GPS. GPS failsafe will initiate a LAND command if GPS failsafe is 

triggered.

Flight range

The control system and telemetry have a range that exceeds the pilots VLOS capability. 

It is not recommended that the aircraft operate beyond 2500 feet from the control point.

Geo Fence

The geofence will be breached if the aircraft flies outside the preset radius and altitude. 

The horizontal fence distance should be set for each job. The fence should be set to 

return the UAS to the launch point if it crosses outside of the operating area.
Flight testing and training area

A suitable flight testing area is required for flight testing and training.

The flight testing area must be located outside and away from structures that could 

interfere with GPS reception.

The flight testing area must be a controlled “sterile” environment not open to the public.

The PIC must have permission to use the area for UAS testing and training.

The flight testing area must be sufficiently large to permit testing of autonomous flight 

modes.

All testing and training flights must be flown below 200 feet above ground level (AGL).

All testing and training flights must be flown more than 500 feet from people not directly 

involved with the UAS activity.

The flight testing area should be located no more than:

 5 nautical miles (NM) from an airport having an operational control tower; or

 3 NM from an airport with a published instrument flight procedure, but not an 

operational tower; or

 2 NM from an airport without a published instrument flight procedure or an 

operational tower; or

 2 NM from a heliport with a published instrument flight procedure

UAS testing

A minimum of two, 15 minute test flights must be performed by a qualified PIC and VO

at a flight testing area to verify correct UAS operation before the aircraft is flown in 

public or civil operations if any of the following occur:

1. An electrical or electronic component, other than the battery, has been replaced 

or repaired

2. Propellers have been replaced with a different type

3. Flight controller hardware or firmware has been updated

4. Control, camera or sensor equipment has changed

5. Battery type or capacity has changed

6. Weight or balance has been altered

7. Motor mounting plates have been re-aligned
UAS flight training recommendations

All UAS training must be conducted within the flight testing and training area.

An instructor is required for all training flights. The instructor may serve as VO.

Before flying a UAS in training, the PIC must hold a current exemption from the FAA for 

the specific UAS being operated.

The instructor should meet the current FAA requirements for operating a UAS in 

addition to having extensive experience piloting similar unmanned or hobby RC aircraft. 

If the instructor cannot meet current FAA airman requirements or does not have a 

current exemption to operate the specific UAS, the instructor is not allowed to fly the 

UA. In this case, the instructor is limited to providing “ground school” training for 

maintenance and operations and is limited to verbally advising the PIC during flight 

training.

The PIC should be competent to manually fly the aircraft using only visual cues. The 

PIC should be capable of discerning the direction and attitude of the aircraft at normal 

flight distances. The PIC should be able to recover the aircraft to level flight from any 

attitude. The PIC should be able to take off, fly, and consistently land the aircraft in the 

landing area without the aid of autonomous control modes. It is recommended that 

initial flight competency be obtained through the use of RC flight simulators and hobby

quadrotors flown indoors.

The PIC should have a thorough understanding of the manual controller and be able to 

quickly switch the system into the correct modes. If a PIC has to pause to think about 

which switch to activate or which way to move the control sticks the PIC is not ready to 

operate the UAS outside of a test area. It is recommended that the same model of 

manual controller should be used for simulator, indoor and outdoor training. 

It is recommended that PIC log at least 6 hours of flight time or 20, 20 minute flights 

before operating the system outside of the training area. The PIC should be able to 

demonstrate evasive emergency maneuvers as directed by the instructor in order to 

maintain appropriate distances from persons, vessels, vehicles and structures.

The PIC should demonstrate a thorough understanding of the telemetry system. The 

telemetry system serves as a redundant controller for the aircraft. The PIC should be 

able to command the aircraft to navigate to specific areas and land using the telemetry 

software.

Before acting as PIC outside of the training area the PIC must demonstrate competency 

to operate the UAS to the satisfaction of the UAS instructor. The PIC must possess a 

written statement from the instructor that the PIC is competent before the PIC operates 

the UAS outside of the test area. This written statement must be retained with the 

operating documents and be available during UAS operations.
UAS ground training

It is recommended that an organization using the UAS develop a training program to 

ensure that all personnel involved with operations are capable of safely operating and 

maintaining the UAS. This training should supplement the FAA certification and UAS 

flight training requirements.

Recommended training topics include but are not limited to:

FAA regulations

Airspace classifications

Basic electrical concepts

Basic aerodynamics

Motor power and thrust

Sensors

Telemetry and GPS

Control theory concepts

Flight controller parameters

Airframe maintenance and repair

Soldering and connectors

Battery care and charging

Ground Control Station Operation

Weather

Operating procedures

Flight planning

Emergency procedures
Battery Care and Charging

The Lithium Polymer battery used in the UAS must be charged with an appropriate 

battery charger. The recommended charger is the Hitec X4 charger. Batteries must be 

charged in accordance with the battery manufacturers recommendations. Batteries 

must be charged out of the aircraft. Batteries should not be charged in an unsupervised 

area or near flammable materials.

Batteries should be labeled with a unique ID number and the date they are placed into 

service.

Before charging the battery, check the individual cell voltages using a battery tester that

simultaneously displays individual cell voltages with a resolution of 1/100 of a volt.

Batteries with dents, puffing or visible damage should be discarded. Batteries with any 

cell under 3.4V should be discarded. 

Batteries with a difference in cell voltages that exceed .05 volts should be balance 

charged in “LiPo Balance” mode. 

Batteries with a difference in cell voltages less than .05 volts should be charged in “LiPo 

Charge” mode.

If, after charging, a difference in cell voltage of more than .05 volts still exists, the 

battery should be discarded. A fully charged battery will have a voltage of 4.2 volts per 

cell.

Batteries should be charged before flight. When a battery will not be used for over a 

month, it should be stored with a partial “storage” charge.

The operator should keep a log of battery information with at least the following 

information. It is recommended that this information be stored electronically on the field 

computer so it is available to the PIC and VO.

Battery Log Data:

Battery ID number

Date of flight

Time of flight

Date recharged

mAH replaced
Flight times

Flight times will vary based on airframe type, payload, battery capacity and battery age. 

Telemetry should be monitored during the flight to determine when to land. The PIC

should land the aircraft when the under load battery voltage during the flight drops to 3.6

volts per cell. This under load voltage threshold will ensure the batteries are not 

discharged below 75% of working capacity. This practice prevents battery damage and 

provides a conservative power reserve sufficient to allow the UAS to return to the 

landing area from any point in the operating area and make a controlled landing. Once 

a baseline flight time has been established for a specific payload the transmitter’s timer 

should be set to one minute less to alert the PIC that the flight should be ended soon. 

Use of the transmitter timer is recommended as a redundant method of monitoring 

power reserves.
UAS maintenance

The UAS must be properly maintained for safe and reliable operation

Damage occurring from normal wear, handling or rough landings must be repaired and 

the system test flown at a flight testing area before the system is flown in production.

The battery should be disconnected during maintenance. If the UAS must be powered 

up for bench testing it must be thoroughly secured so that it cannot lift off. When 

conducting any maintenance where power is applied, personnel must stay well clear of 

the aircraft.

The UAS uses high quality brushless motors with sealed bearings. No lubrication or 

maintenance is required. Each of the four motors should be inspected before each day 

of flying by checking the following items:

1. Rotate the motor by hand to feel for rough bearings.

2. Pull the rotor upwards to check for worn washers or missing “c” clips

3. Check for loose motor mounting screws

4. Check for loose propeller mounting screws

5. Check for loose arms and loose or mis-alignment of the motor mounting plates

6. Determine the cause of any high temperatures noted after flight and correct

Motors with worn parts must be replaced or repaired and test flown for at least 30 

minutes. Motors should be carefully inspected during this “break in” period.

The propellers should be inspected before each flight. Propellers with chips, deep 

scratches or cracks must be replaced. All propellers must be from the same 

manufacturer and of the same model. If an identical replacement is not available the 

entire set of propellers must be replaced and a test flight conducted.

It is recommended that ESCs be directly soldered to the motor leads. The ESCs are 

sensitive to intermittent connections and eliminating 24 connector parts increases the 

reliability of the system. Soldering must be performed by a technician capable of

making good solder connections. All solder points must be insulated with heat shrink 

tubing. If an ESC requires replacement it must be of the same manufacturer, model, 

firmware and circuit design. If an identical replacement is not available the entire set 

must be replaced with an equivalent optically isolated non-BEC model with firmware 

optimized for multirotor use. Recalibration of all ESCs must be performed when any 

ESC is replaced.
Maintenance Log

UAS maintenance should be documented in an electronic maintenance log.

Maintenance information should include but is not limited to:

The date the UAS was placed into service

The date and type of maintenance performed

The manufacturer, model, cost and vendor of all replacement parts purchased

The date and the specific part replaced
Flight Operating Procedures

The procedures below are a recommended minimum and should be modified and 

documented as needed for specific types of work.

Flight planning checklist

 Develop and review flight plan

 Verify the flight plan conforms to FAA airspace regulations

 Create a flight data folder on field computer

 Fill out flight log with initial information

o Date, time, location, weather, PIC, VO

 Charge batteries and record data in battery log

 Check weather, NOTAMs and TFRs

 Adjust flight lines to align with current wind direction if possible

 Put on personal protective equipment as required by organizational policy

 Perform an on-site visual confirmation that the flight plan avoids obstructions.

 Set and verify the appropriate geofence radius for the flight plan

 Brief personnel on the ground on the upcoming flights and potential hazards.

Pre flight inspection checklist

 Inspect props for damage or loose screws

 Inspect airframe for damage

 Make a final test of battery voltage and cell balance

 Verify charged camera battery and available space on SD card

Pre launch checklist

 Clear the flight area of unnecessary and unauthorized personnel

 Power up ground telemetry system

 Power up the PIC controller

 Verify proper flight mode and stick positions on PIC controller

 Position aircraft at takeoff point

 Power up aircraft

 Connect Telemetry

 Verify altimeter relative altitude is reading zero

 Download flight plan to the flight controller

 Power up camera and set camera mode

 Check GPS for a minimum of 8 satellites, battery status, attitude and heading

 Visually verify that no other aircraft are nearby
Flying procedures

 Take off

 Verify aircraft stability and position holding performance

 Verify nominal telemetry readings

 Activate autonomous mode if necessary

 During the flight the Observer should report the following information to the PIC:

o Nearby aircraft

o Mission status and waypoint count

o Battery status

o Any deviation from the flight plan or other anomaly

 The Observer should ensure that the landing area remains clear of unnecessary 

or unauthorized personnel.

 Land

Post Flight checklist

 Disconnect the flight battery

 Place battery in discharged battery storage box

 Power down the PIC controller

 Disconnect telemetry

 Immediately check for excessive motor or ESC temperatures. Temperatures 

should only be slightly above ambient air temperature. Record any motors or 

ESCs running hot in the maintenance log

 Power down the camera

 Copy telemetry logs to flight log folder

 Retrieve images from camera

 Replace or recharge battery in camera

 Complete flight log folder

o Duration, document UA performance issues

In the event of a crash the PIC should investigate and document the flight conditions 

and suspected reasons for the crash. Documentation is important so the appropriate 

repairs can be made. In the event of injury to personnel or damage to property, the PIC 

must follow all FAA regulations regarding reporting of the incident as well as following 

organizational and OSHA requirements.

Any incident, accident, or flight operation that transgresses the lateral or vertical 

boundaries of the operational area as defined by the applicable COA must be reported 

to the FAA's UAS Integration Office (AFS-80) within 24 hours. Accidents must be 

reported to the National Transportation Safety Board (NTSB) per instructions contained 

on the NTSB Web site: www.ntsb.gov
K680-4 Specifications:

Airframe Type Quadrotor

Weight including battery 4.1 lbs

Weight with camera 4.5 lbs nominal

Frame size (motor circle) 27” (680mm)

Frame material Carbon fiber

Motor Type Brushless outrunner

Propeller Diameter 13”

Propeller Pitch 5.5” (140mm)

Battery Lithium Polymer

Cell Count 4

Voltage 14.4V

Capacity 3300 mAH

Flight Characteristics

Climb Rate 8.2 feet per second (firmware limited)

Decent Rate 13 feet per second (firmware limited)

Endurance 15 minutes

Reserve power 5 minutes

Control

Spektrum DX9

Frequency 2.4 GHz

Modulation DSMX

FCC compliance Part 15, unlicensed

Telemetry

Frequency 915 MHz

Modulation FSK

Output Power 100 mW

Sensitivity -117 dBm

Range 1 KM

FCC compliance Part 15, unlicensed

Camera Equipment

Camera Canon S110, GoPro Hero or similar
K1000-4 Specifications:

Airframe Type Quadrotor

Weight including battery 3.7 lbs

Weight with camera 4.8 lbs (with NEX7)

Frame size (motor circle) 39.5” (1000mm)

Frame Material Fiberglass reinforced EPP

Motor Type Brushless outrunner

Propeller Diameter 15”

Propeller Pitch 5.5”

Battery Lithium Polymer

Cell Count 4

Nominal Voltage 14.4V

Nominal Capacity 4000 mAH

Flight Characteristics

Climb Rate 8.2 feet per second (firmware limited)

Decent Rate 13 feet per second (firmware limited)

Endurance 15 minutes

Reserve Power 5 minutes

Control

Spektrum DX9

Frequency 2.4 GHz

Modulation DSMX

FCC compliance Part 15, unlicensed

Telemetry

Frequency 915 MHz

Modulation FSK

Output Power 100 mW

Sensitivity -117 dBm

Range 1 KM

FCC compliance Part 15, unlicensed

Camera Equipment

Camera Sony NEX 5/7 or similar
ZETA FX-61 Specifications:

Airframe Type Flying Wing

Flying weight 4.2 lbs with QX1

Wingspan 61”

Motor Type Brushless outrunner

Propeller Diameter 6”

Propeller Pitch 5.5”

Battery Lithium Polymer

Cell Count 3

Nominal Voltage 11.1 V

Nominal Capacity 3300 mAH

Flight Characteristics

Airspeed 28 mph

Climb Rate 25 feet per second

Decent Rate 15 feet per second

Endurance 25 minutes

Reserve Power 10 minutes

Control

Spektrum DX9

Frequency 2.4 GHz

Modulation DSMX

FCC compliance Part 15, unlicensed

Telemetry

Frequency 915 MHz

Modulation FSK

Output Power 100 mW

Sensitivity -117 dBm

Range approximately 0.75 miles

FCC compliance Part 15, unlicensed

Camera 

Canon S110, GoPro Hero, Sony QX1 or similar