UK CAA – SN-2018/010 – DJI Battery TB50 and TB55

Notice To DJI Drone Operators

SN-2018/010: Small Unmanned Aircraft – DJI Battery TB50 and TB55 In-Flight Power Failures

For ease the original Safety Notice is extracted below but should be confirmed on the latest document available on the UK CAA website

1 Introduction

1.1 This Safety Notice provides updated information regarding the points detailed in Safety Notice
SN–2018/009, which is now cancelled.
1.2 This Safety Notice applies to operators of multi-rotor small unmanned aircraft utilising
DJI battery model TB50 or TB55, including all DJI Matrice 200 series (which includes the 200,
210 and 210 RTK platforms) and the DJI Inspire 2 (the Affected SUA).
1.3 A small number of incidents have been recently reported where the aircraft has suffered a
complete loss of power during flight, despite indications that there was sufficient battery charge
still remaining. In each case, this resulted in the aircraft falling directly to the ground due to the
immediate loss of lift with the remote pilot unable to control its subsequent flight path. The small
unmanned aircraft were damaged upon impact, but the CAA has not received any reports of
injuries to people or other property.
1.4 Investigation by the manufacturer has stated that this issue is related to the battery firmware in
the TB50/55 series of batteries. Although the issue is still under review, the CAA has received
a technical update from the manufacturer which has enabled a review of the previously imposed
1.5 The purpose of thisSafety Notice is to highlight the requirement for the SUA operator and/or
remote pilot to be reasonably satisfied that the flight can be safely made (Air Navigation Order
2016 (ANO) article 94(2)), restrict overflight of persons at any height, to temporarily limit the
scope of certain operational authorisations issued to operators of the Affected SUA, and to
provide updated information regarding battery management requirements while the Affected
SUA are airborne.

2 Compliance/Action to be Taken

2.1 This Safety Notice requires the following actions to be taken:

a) Provisional Suspension of Operations
i) In accordance with Air Navigation Order article 257 operators of Affected SUA are
hereby directed not to permit any flight that involves overflight of any persons, whether
or not they are under the control of the operator or remote-pilot, at any height until further
ii) In accordance with Air Navigation Order article 253, any element of any permission
or exemption based on an Operating Safety Case, issued by the CAA to an SUA
operator which permits the operation of an Affected SUA to be operated:
• within 50 metres of any person;
• within 50 metres of any, vessel, vehicle or structure which is not under the control
of the SUA Operator or remote pilot of the SUA;
• over or within 150 metres of an open – air assembly of more than 1,000 persons;
is provisionally suspended until further notice. This does not affect the ordinary operation
of Article 95 of the Air Navigation Order.
Note: The previous suspension of permissions and/or exemptions involving operations
over or within 150 metres of a congested area (e.g. as stated within a Standard
Permission), or when employing Extended Visual Line of Sight techniques, are now
iii) These limitations will be subject to regular review. As soon as further updates have
been obtained from the manufacturer, and the CAA is satisfied that this has been
addressed in a satisfactory manner, the CAA will then issue a further update via the
SkyWise alerts portal on the CAA website.

b) Battery Management Guidance/aircraft operating limitations
i) SUA Operator and remote pilots must refer to the guidance and instructions
provided by the manufacturer on its website:
ii) If, at any time while the aircraft is in flight, the indicated voltage is displayed as 3.7
V or lower, the aircraft must be landed immediately, as recommended by the
manufacturer. Remote pilots should therefore plan their flights so that they can land
with a minimum of 3.7 V indicated (approximately 30% of full charge).
iii) Remote pilots must not rely on the state of charge only.

c) Emergency Services Operations
i) Due to the unique nature of emergency services operations, the privileges contained
within General Exemption E 4506 (ORS4 No. 1233) may continue to be exercised whilst
using the Affected SUA, provided that the potential risks highlighted in this Safety Notice
have been considered within the decision to proceed and the overflight of uninvolved
persons is minimised.

d) Occurrence Reporting.
Operators or remote pilots experiencing further occurrences, or related issues, should
report these directly to both the manufacturer and the CAA. Guidance on how to provide
reports to the CAA can be found at

3 Queries

3.1 Any queries as a result of this communication should be addressed to the following e-mail
address:, with the subject line ‘Safety Notice – DJI Battery TB50 and
TB55 In-Flight Power Failures’.
3.2 Technical advice should be sought directly from the manufacturer.

4 Cancellation

4.1 This Safety Notice will remain in force until further notice.


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