Important CAA Safety Announcement Regarding TB50 & TB55 Batteries

1 Introduction
1.1 This Safety Notice provides updated information regarding the points detailed in Safety Notice
SN–2018/010, which is now canceled.

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 Following a small number of reported incidents where the TB50/55 series of batteries has
resulted in the complete loss of power of an Affected SUA whilst airborne, the manufacturer
released a firmware update to the battery management system on 16 November 2018 and is
working on a permanent fix to the issue.

1.4 The purpose of the Safety Notice is to draw the attention of SUA operators to:
a) the firmware update that has been released by the manufacturer in order to address the
power failure issues relating to the TB50/55 series of batteries.
b) the operating limitations associated with the firmware update.

1.5 SUA operators and remote pilots are reminded of their responsibility to be reasonably satisfied
that the flight can be safely made (Air Navigation Order 2016 (ANO) article 94(2)) and of the
requirements of ANO article 241 that a person must not recklessly or negligently cause or permit
an aircraft (ie. the Affected SUA) to endanger any person or property.

2 Compliance/Action to be Taken
2.1 SUA operators and remote pilots should follow the advice and guidance provided by the
manufacturer to install the full suite of firmware updates provided for users of the TB50 and
TB55 batteries. Guidance can be found at:

2.2 Depending on the status of the firmware update that has been installed, the following operating
limits apply:

a) If SUA operators and remote pilots of the Affected SUA are able to confirm that the full
suite of firmware updates that were released on or after 16 November 2018 have been
successfully installed, the Affected SUA may be operated in accordance with the
requirements of the ANO 2016 and any permission or exemption that has been issued
by the CAA.

b) If SUA operators and remote pilots of the Affected SUA cannot complete the firmware
updates or cannot confirm that the battery firmware has been updated:

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.

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; or
• over or within 150 metres of an open – air assembly of more than 1,000 persons;
is suspended. This does not affect the ordinary operation of Article 95 of the Air
Navigation Order.

iii) If, at any time while the aircraft is in flight, the indicated voltage is displayed as 3.7V
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 3.7V indicated (approximately 30% of full charge).

iv) Remote pilots must not rely on the state of charge only.
c) Emergency Services Operations
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.

Civil Aviation Authority Safety Notice SN–2018/011
Page 3 of 3
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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