Page 279 - UK Air Operations Regulations (Consolidated) 201121

Part CAT - ANNEX IV - Commercial Air Transport Operations

air/fuel mixture in the tank being in the combustible range at ambient temperatures. The
extra precautions set out below are advisable to avoid arcing in the tank due to
electrostatic discharge. The risk of this type of arcing can be minimised by the use of a
static dissipation additive in the fuel. When this additive is present in the proportions stated
in the fuel specification, the normal fuelling precautions set out below are considered
adequate.
(c) Wide-cut fuel is considered to be ‘involved’ when it is being supplied or when it is already
present in aircraft fuel tanks.
(d) When wide-cut fuel has been used, this should be recorded in the technical log. The next
two uplifts of fuel should be treated as though they too involved the use of wide-cut fuel.
(e) When refuelling/defuelling with turbine fuels not containing a static dissipator, and where
wide- cut fuels are involved, a substantial reduction on fuelling flow rate is advisable.
Reduced flow rate, as recommended by fuel suppliers and/or aeroplane manufacturers,
has the following benefits:
(1) it allows more time for any static charge build-up in the fuelling equipment to
dissipate before the fuel enters the tank;
(2) it reduces any charge which may build up due to splashing; and
(3) until the fuel inlet point is immersed, it reduces misting in the tank and consequently
the extension of the flammable range of the fuel.
(f) The flow rate reduction necessary is dependent upon the fuelling equipment in use and the
type of filtration employed on the aeroplane fuelling distribution system. It is difficult,
therefore, to quote precise flow rates. Reduction in flow rate is advisable whether pressure
fuelling or over- wing fuelling is employed.
(g) With over-wing fuelling, splashing should be avoided by making sure that the delivery
nozzle extends as far as practicable into the tank. Caution should be exercised to avoid
damaging bag tanks with the nozzle.
CAT.OP.MPA.205 Push back and towing — aeroplanes
Push back and towing procedures specified by the operator shall be conducted in accordance with
established aviation standards and procedures.
CAT.OP.MPA.205 AMC1 Push back and towing — aeroplanes
BARLESS TOWING
(a) Barless towing should be based on the applicable SAE ARP (Aerospace Recommended
Practices), i.e. 4852B/4853B/5283/5284/5285 (as amended).
(b) Pre- or post-taxi positioning of the aeroplanes should only be executed by barless towing if
one of the following conditions are met:
(1) an aeroplane is protected by its own design from damage to the nose wheel steering
system;
(2) a system/procedure is provided to alert the flight crew that damage referred to in (b)
(1) may have or has occurred;
(3) the towing vehicle is designed to prevent damage to the aeroplane type; or
(4) the aeroplane manufacturer has published procedures and these are included in the
operations manual.
CAT.OP.MPA.210 Crew members at stations
(a) Flight crew members
(1) During take-off and landing each flight crew member required to be on duty in the
flight crew compartment shall be at the assigned station.
(2) During all other phases of flight each flight crew member required to be on duty in
the flight crew compartment shall remain at the assigned station, unless absence is
necessary for the performance of duties in connection with the operation or for
physiological needs, provided at least one suitably qualified pilot remains at the
controls of the aircraft at all times.
(3) During all phases of flight each flight crew member required to be on duty in the flight
crew compartment shall remain alert. If a lack of alertness is encountered,
appropriate countermeasures shall be used. If unexpected fatigue is experienced, a
controlled rest procedure, organised by the commander, may be used if workload
permits. Controlled rest taken in this way shall not be considered to be part of a rest
period for purposes of calculating flight time limitations nor used to justify any
extension of the duty period.
(b) Cabin crew members
During critical phases of flight, each cabin crew member shall be seated at the assigned
station and shall not perform any activities other than those required for the safe operation
of the aircraft.
CAT.OP.MPA.210 GM1 Crew members at stations
MITIGATING MEASURES — CONTROLLED REST
(a) This GM addresses controlled rest taken by the minimum certified flight crew. It is not
related to planned in-flight rest by members of an augmented crew.
(b) Although flight crew members should stay alert at all times during flight, unexpected fatigue
can occur as a result of sleep disturbance and circadian disruption. To cover for this
unexpected fatigue, and to regain a high level of alertness, a controlled rest procedure in
the flight crew compartment, organised by the commander may be used, if workload
permits and a controlled rest procedure is described in the operations manual. ‘Controlled
rest’ means a period of time ‘off task’ that may include actual sleep. The use of controlled
rest has been shown to significantly increase the levels of alertness during the later
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