CONFIDENTIAL DOCUMENT

Author Document Title

SenseFly eBee: justification of airworthiness and safety assessment

Date Version

23.12.13 V1.0

Proprietary Information Submitted under 14 C.F.R. 11.35(b) Page 1/9

eBee maintenance procedures

 

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Version Date Description Author

V 1.0 23.12.2013 Technical documentation SenseFly
CONFIDENTIAL DOCUMENT

Author Document Title

SenseFly eBee: justification of airworthiness and safety assessment

Date Version

23.12.13 V1.0

Proprietary Information Submitted under 14 C.F.R. 11.35(b) Page 2/9

Table of content

1 INTRODUCTION ........................................................................................................................................ 3

2 REGULAR MAINTENANCE: CLEANING, AIRFRAME INSPECTION AND STORAGE............. 3

2.1 AFTER-FLIGHT CLEANING.......................................................................................................................... 3

2.2 STORAGE................................................................................................................................................... 3

2.3 AFTER-FLIGHT/ PRE-FLIGHT VISUAL INSPECTION ...................................................................................... 3

2.4 CORRECTIVE ACTIONS ............................................................................................................................... 4

2.4.1 Pre-flight errors................................................................................................................................. 4

2.4.2 Take-off vetos..................................................................................................................................... 5

3 PREVENTIVE MAINTENANCE: FULL AIRFRAME AND SENSOR INSPECTION...................... 7

3.1 CHECK 1: SERVOS ..................................................................................................................................... 7

3.2 CHECK 2: INERTIAL SENSORS .................................................................................................................... 7

3.3 CHECK 3: BAROMETRIC PRESSURE SENSOR ............................................................................................... 7

3.4 CHECK 4: AIR SPEED SENSOR .................................................................................................................... 8

4 CORRECTIVE MAINTENANCE ............................................................................................................. 8

5 MAINTENANCE OF THE FLIGHT MANAGEMENT SOFTWARE: CHECK THE UPDATES.... 8

6 REPORTING A PROBLEM WITH THE EBEE ..................................................................................... 9
CONFIDENTIAL DOCUMENT

Author Document Title

SenseFly eBee: justification of airworthiness and safety assessment

Date Version

23.12.13 V1.0

Proprietary Information Submitted under 14 C.F.R. 11.35(b) Page 3/9

1 Introduction

SenseFly is a Swiss company founded at the end of 2009. The company designs and produces very 

light (500-750 grams) autonomous fixed-wing mini-drones for mapping and aerial photography and 

develops also a very powerful software for flight simulation and flight management: eMotion.

SenseFly masters all aspects of mini-drone development (from hardware to software) and is 

therefore capable of reaching a very high level of integration.

2 Regular Maintenance: Cleaning, airframe inspection and storage

2.1 After-flight cleaning

After every flight, we recommend our operator to use a damp cloth to wipe off dirt from the eBee.

Be careful never to bring the eBee into direct contact with water, as this may damage the electronics 

within the eBee airframe.

2.2 Storage 

In order to avoid structural deformation of the wings, it is recommended to store the eBee either in 

its transport case or on a flat surface at room temperature. Avoid exposing the eBee to high 

temperature for prolonged periods of time. In particular, leaving the eBee exposed to the sun in a 

car should be avoided.

2.3 After-flight/ Pre-flight visual inspection

Before a new mission and after every flight, the operator shall make a visual inspection of the 

airframe, wings and the propeller, in order to look for cracks or damages.

Each operator shall inspect (where applicable) the following components of the UAV:

(a) Body: Fabric and skin - for deterioration, distortion, and other evidence of failure;

(b) Flight controls - for deterioration or improper installation;

(c) Batteries - for improper installation;

(d) Engine section - for improper installation;

(e) Propeller section (blades and rubber bands) - for cracks, nicks, binds or deterioration;

(f) All components of the wings, body-section assembly and flight surfaces for poor general 

condition, fabric or skin deterioration, distortion, evidence of failure, and insecurity of attachment;

(g) Camera system for improper installation, poor general condition, defects, and insecure 

attachment;

(h) Radio and electronic equipment, sensors (Pitot, optical ground sensor) - for improper installation 

and/or cracks/obstructions,

Besides, the autopilot will manage several pre-flight tests by itself in order to ensure that the flight 

will be conducted safely (see part D, corrective actions).
CONFIDENTIAL DOCUMENT

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SenseFly eBee: justification of airworthiness and safety assessment

Date Version

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Proprietary Information Submitted under 14 C.F.R. 11.35(b) Page 4/9

2.4 Corrective actions

The eBee can generate several types of error messages before flights. Some of these messages 

are minor and simply need to be acknowledged through eMotion 2, whereas others require more 

specific action from the user. As long as the eBee is connected to eMotion 2, error messages will 

appear in the Status Panel in the Map Area, as well as in the Drone Status panel of the Flight 

Monitoring tab.

Error messages are divided into two categories:

2.4.1 Pre-flight errors

As soon as the battery is connected to the eBee it performs a series of pre-flight checks to 

thoroughly test its on-board systems. The start-up process is described in detail in section 

‘Preparing the eBee for flight’ on page 25 of the user manual. If an error occurs during these preflight checks the status LED will blink red and a description of the error will appear in eMotion 2. In 

most cases, re-connecting the battery will suffice to remove the error. 
CONFIDENTIAL DOCUMENT

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SenseFly eBee: justification of airworthiness and safety assessment

Date Version

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Figure 1: Pre-flight tests

2.4.2 Take-off vetos

After successfully completing pre-flight checks the status LED becomes a solid green to indicate 

that the eBee is ready for take-off. At this point the eBee continues to monitor its sensors and battery

level. If at any point the eBee detects a condition that prevents it from beginning the automatic takeoff procedure it displays a Take-off veto in eMotion 2 and the status LED changes to a blue pulse. 

Once the Take-off veto is cleared the status LED returns to a solid green colour to indicate that the 

eBee is ready for take-off. 
CONFIDENTIAL DOCUMENT

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SenseFly eBee: justification of airworthiness and safety assessment

Date Version

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Figure 2: Take Off Vetos
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Date Version

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3 Preventive maintenance: Full airframe and sensor inspection

Beyond the general airframe inspection that is performed before every flight, SenseFly recommends 

that the operator performs a full airframe and sensor inspection regularly (every 10 hours, 3 times 

less than the calculated MTBF to have the same safety rate as for Manned Aircraft, see Annex 4) to 

keep the eBee in good operating condition. The inspection includes 4 steps:

3.1 Check 1: Servos

The servos are the two actuators connected through a servo connection mechanism to both 

ailerons. A servo failure may completely prevent suitable flight control. It is therefore important to 

check them properly.

To check the servos, follow these steps:

1. Make sure the left stick of the remote control is all the way down to keep the motor off. Remove 

the propeller to avoid any harm in case it suddenly starts spinning.

2. Switch the eBee on by connecting the battery.

3. Connect to eMotion 2. Ensure that the ‘Enable assisted manual control’ setting in the Flight 

Parameters tab is not selected.

4. Switch the remote control on.

5. Move the right stick on the remote control and check the aileron motion.

6. When done, switch the remote control off. The ailerons must smoothly and quickly follow the 

stick. When the stick is not moved, the ailerons must stay still. When travelling from one end to the 

other, fast or slow, the ailerons must smoothly follow without twitching. In case of doubt, take a short 

video and follow the instructions in section ‘Reporting a problem with your eBee’ on page 117 of the 

user manual for advice.

3.2 Check 2: Inertial sensors

The inertial sensors are used by the autopilot to compute the attitude (i.e. its orientation in space) of 

the eBee. The attitude is displayed by the artificial horizon in the Flight Monitoring tab of eMotion 2. 

To check the inertial sensors, follow these steps:

1. Switch the eBee on by connecting the battery and connect to eMotion 2.

2. Put the eBee on a flat surface (typically an office floor) and check that the artificial horizon is level.

3. Take the eBee with your hand and put it in different orientation. Make sure that the artificial 

horizon displays the corresponding orientation. The artificial horizon should follow smoothly the 

motion of the eBee and it should not drift when the eBee is not moving. In case of doubt, take a 

short video and follow the instructions in section ‘Reporting a problem with your eBee’ on page 117 

of the user manual for advice.

3.3 Check 3: Barometric pressure sensor

The barometric pressure sensor is used to measure the height from the take-off location altitude. To 

check it, follow these steps:

1. Switch the eBee on by connecting the battery and connect to eMotion 2.
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Author Document Title

SenseFly eBee: justification of airworthiness and safety assessment

Date Version

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Proprietary Information Submitted under 14 C.F.R. 11.35(b) Page 8/9

2. Move the eBee from your feet to above your head (about 2 m height variation).

3. Check the height on the vertical bar right of the artificial horizon or in the Status Panel next to the 

eBee icon on the map). 

The displayed height should follow the eBee motion, i.e. if the eBee is raised by 2 m, the height 

reading should increase by about 2 m. When the eBee is not moving, the height reading may slowly 

drift by up to ±10 m.

3.4 Check 4: Air speed sensor

The air speed sensor is connected to the Pitot probe by a pair of tubes. To check it, follow these 

steps:

1. Visually check the Pitot probe. Make sure that it is properly fixed to the airframe and that both 

tubes are properly attached and not damaged.

2. Switch the eBee on by connecting the battery and connect to eMotion 2.

3. Gently blow into the front opening of the Pitot tube. The airflow direction should match the natural 

flow experienced in flight.

4. Check the air speed displayed on the vertical bar left of the artificial horizon. At rest, the displayed 

air speed should be close to zero (it may drift up to about 2 m/s). When blowing in the Pitot probe, 

the air speed should shortly rise up to 8 to 14 m/s.

4 Corrective maintenance

1. Small repairs of cracks in the airframe can be done using contact glue such as UHU® POR glue. 

Take care to use only contact glues that are specifically designed for Expanded Polypropylene 

(EPP). If you have doubts about the extent of the damage, always contact your distributor to verify if 

the damage can be easily repaired by yourself or if you need to send your eBee in for repair to.

2. If you detect cracks in the propeller, change it by referring to the user manual.

5 Maintenance of the flight management software: check the updates

Occasionally, senseFly Ltd releases a software upgrade for the eBee to provide additional features 

to our users or to correct potential issues. When a new version is available an email is sent with 

download instructions to all users of a eBee. We recommend however that the operator checks the 

senseFly Ltd website regularly for updates to ensure he has the latest version of the software. To 

upgrade eMotion 2 or Postflight Terra 3D-EB to the latest version, the user has to download the 

installer from the senseFly Ltd website and follow the standard install procedure (see section 

‘Installing eMotion 2, Postflight Terra 3D-EB and the radio module drivers’ in the user manual). It is 

not necessary to uninstall the previous version of eMotion 2 before installing the new one. Every 

version of eMotion 2 is packaged with an accompanying firmware revision which must be installed 

on the eBee before it can be used. 
CONFIDENTIAL DOCUMENT

Author Document Title

SenseFly eBee: justification of airworthiness and safety assessment

Date Version

23.12.13 V1.0

Proprietary Information Submitted under 14 C.F.R. 11.35(b) Page 9/9

6 Reporting a problem with the eBee

If there is a problem with your eBee, whether it is a software malfunction, damaged airframe or any 

other problem, we recommend the following actions:

1. If there is an error message displayed in eMotion 2, begin by checking section ‘Troubleshooting’ 

on page 101 of the user manual to see if there is a solution to the particular message.

2. Check the on-line Questions & Answers section on SenseFly’s website to see if there is a solution 

to the problem: http://www.sensefly.com/faq.html

3. If the operator has still not found a solution, contact one eBee reseller. Please include the 

following information with the inquiry:

- The serial number of the eBee.

- A short description of the problem.

- The Drone Flight Log file of the flight that had a problem, if available.

- The eMotion Flight Log file of the flight that had a problem.