4.7 General Guidance on the Use of Aircraft

Written by David Jardine-Smith. Posted in C4 - Command, Control, Coordination & Communications (

Date Written
Wednesday, 08 June 2016
International Maritime Rescue Federation
Type of Paper
  • Guidance Paper
  • English



This paper discusses:

o   types of aircraft that may become involved in an MRO
o   fixed-wing aircraft roles in an MRO
o   rotary-wing aircraft roles in an MRO, in addition
      delivery of specialist personnel, equipment or supplies
      the rescue of people who would otherwise hinder the operation
      medical evacuation of urgent cases from other rescue units
o   keeping aircraft on stand-by / in reserve
o   matching aircraft capabilities to the circumstances and tasks required

1 Overview

1 Overview

1.1 For a general introduction to the IMRF's mass rescue operations (MRO) guidance, please see MRO guidance paper 1.1 'Complex incident planning – the challenge: acknowledging the problem, and mass rescue incident types'. The guidance in this section focuses on various aspects of the coordination question. Guidance paper 4.1 introduces the subject.

1.2 Specific issues relating to the coordination of aircraft involved in an MRO are covered in guidance papers 4.3 (on SAR mission coordination) and 4.5 (aircraft coordination). Issues relating to the retrieval of people in distress are discussed in guidance paper 2.4; accounting for everyone involved in guidance paper 2.5; and the transfer of survivors to places of safety in guidance papers 2.6 & 2.7. Providing on-board support as well as, or instead of, rescue is discussed in guidance paper 3.3. The use of surface units is discussed in guidance paper 4.6, and the efficient communications necessary to overall success are considered in guidance paper 4.9.

1.3 All of these are aspects of, or relate to, the use of aircraft in an MRO, and the reader is referred to the relevant guidance papers listed above – and to the guidance in the International Aeronautical and Maritime Search and Rescue (IAMSAR) Manual. Volume II of the Manual provides the main international guidance on the coordination of SAR, including MROs; and Volume III, which is carried by most ships and aircraft trading internationally, is the main reference document for these SAR facilities.

1.4 In this guidance paper we consider some aspects of the use of aircraft in MROs not covered elsewhere.

1.5 A significant amount of additional guidance on multiple aircraft SAR operations has been added to all three volumes of the IAMSAR Manual in its 2016 edition. In particular, procedures and principles are described in a new chapter 7 added to IAMSAR Volume II and a new section 5 added to Volume III. This guidance should be referred to by MRO planners. Significant points drawn from this new text are included in this paper and in guidance paper 4.5.

2 Types of Aircraft that May Become Involved in a MRO

2 Types of Aircraft that May Become Involved in an MRO

2.1 While any type of aircraft might become involved in an MRO, most military, commercial and general aviation aircraft – especially fixed-wing aircraft – are unlikely to have more of a role than, perhaps, initial communications and locating and standing by people in distress until rescue units can arrive, as discussed in general in the IAMSAR Manual. For our purposes here, then, we will focus on aircraft which are designated SAR units or specialist support aircraft such as transport helicopters used by the offshore industries.

IAMSAR defines a 'SAR Unit' or 'SRU' as "a unit composed of trained personnel and provided with equipment suitable for the expeditious conduct of search and rescue operations".

2.2 Not all helicopters are suitable for operations over water; not all are winch-fitted; and in many cases landing on ships to pick people up or to drop them off will be too unsafe to be attempted. On the other hand, winch-fitted maritime SAR helicopters are, of course, a major aid to maritime rescue generally, being able to transit quickly to the scene of distress, to deliver specialist assistance, to retrieve people who may not be accessible by surface rescue units, and to deliver them rapidly to a place of safety. If available, helicopters will certainly have a place in an MRO – but it is worth considering how they can best be used: see below.

2.3 Fixed-wing aircraft cannot conduct rescues (except in highly specialised circumstances unlikely to be relevant here) but also have rapid transit times – more rapid than helicopters in most cases – and the ability to deliver supporting equipment and, sometimes, specialist assistance. SAR aircraft are able to cover search areas rapidly and effectively, and they make good communications platforms. They can reach remoter areas and/or remain on-scene longer than most helicopters; their height can enable them to act as communications relays; and – if they and the relevant ground stations are suitably equipped – they can stream back imagery and other on-scene data, of considerable use to the Rescue Coordination Centre (RCC) and other remote responders. Finally, as discussed in guidance paper 4.5, if the area of SAR action is not within the coverage of an Air Traffic Services (ATS) unit, a fixed-wing aircraft with a SAR-trained crew is likely to be the best choice as Aircraft Coordinator (ACO).

2.4 SAR aircraft of all types can be very effective search units, combining a 'bird's-eye view' and, ideally, remote sensing equipment with good area coverage. Radar, emergency beacon detection, infra-red cameras etc are life-saving aids – particularly in the event of an uncontrolled evacuation leaving people in the water or when search objects are scattered.

2.5 At the time of writing, Remotely Piloted Aircraft or Unmanned Aircraft Systems are being widely discussed in the maritime SAR context. It is possible to envisage their use in all the ways briefly discussed above. They have the additional benefit of being able to be used, if necessary, in circumstances which would be too hazardous for an aircraft with crew aboard. They are often cheaper to operate than a manned aircraft and can stay airborne longer: crew fatigue is dealt with at the controlling station, not by having to return the aircraft to base for a crew change. They are likely to bring significant benefits to the communications, surveillance and search aspects of maritime SAR, and it is not too far-fetched to envisage equipment delivery and even rescue roles for them in the future.

3 Aircraft Roles in an MRO

3 Aircraft Roles in an MRO

3.1 A mass rescue operation is likely to be very complex and to involve a wide mix of maritime, aeronautical and land SAR facilities. While, as discussed in guidance paper 4.5, there have been cases in which helicopters have played a leading role in the rescue, it will more usually be the case that aircraft play supporting roles. In the case of fixed-wing aircraft these will be in coordination, search and surveillance, as discussed above. Helicopters are probably best thought of as 'specialist' rescuers in MROs.

3.2 A helicopter is an excellent piece of SAR equipment – but there is no denying that it needs space, is noisy, it creates both downwash and distraction, and it cannot rescue very many people at once.

Also known as 'rotor wind' or 'down-draught', this is the downward rush of air generated by the rotors of a hovering helicopter. It can move unsecured items, to the hazard of people in the vicinity – and potentially to the aircraft itself if it sucks loose material into its engines – and has been known to blow liferafts etc aside; even to capsize them.

Its use should therefore be carefully planned in an MRO, where there are many people in distress and other things going on. The noise of a nearby helicopter can very severely disrupt communications, both face-to-face and by radio, and has been known to disorientate people, especially frightened survivors. The downwash can cause injury and/or interfere with other SAR action. And, for flight safety reasons, only one aircraft is usually able to operate at once in a small area such as the winching areas available on all but the biggest ships. (It should be noted, however, that in specific circumstances such as the evacuation of an offshore installation, with a helideck still operable and experienced controllers and aircrew, helicopter evacuation will be preferable.)

3.3 In general, helicopters are better reserved in MROs for what they are best at: rapid transits and 'surgical' delivery and extraction.

3.4 If specialists and/or specialist equipment or supplies are needed to be placed aboard the casualty (see guidance paper 3.3) or aboard rescue units to support their crews (see guidance papers 2.4 & 4.6) a helicopter will often be the best way to do it – able to move material and personnel rapidly to the scene and to winch them aboard if landing-on is not an option.

3.5 Similarly, helicopters are good for the rescue of 'difficult' cases. As discussed in guidance paper 2.4, it is likely to take a significant amount of time and effort to extract an injured or disabled or very elderly person using standard evacuation methods and equipment, and then to transfer them from survival craft into rescue units. If such people are given priority, others will be held up. To be blunt, more – perhaps many more – able-bodied people can be rescued in the same time by standard means than those who are less able.

3.6 A solution to this problem is to use helicopters to remove those who will delay the standard evacuation procedure. It is an added benefit that this will usually also mean that these vulnerable people can be transferred to appropriate care more rapidly because they will already be aboard the helicopter.

3.7 Similarly, helicopters may be used to take urgent medical cases off rescue units as they are identified by triage (see guidance paper 2.6) and on medical advice, transferring them more quickly to specialist medical care and easing the load on the rescue units' crews.

3.8 It follows that aircraft should be deployed wisely in an MRO. The SMC should move them to forward bases in the early stages, to have them ready for use, but should not send all available air assets straight to the scene as a first reaction – and certainly not before an ACO is appointed. There is no point in having aircraft – helicopters in particular – 'on hold' in the area, burning fuel and causing difficulties for other rescue workers if they come close before there is specific work for them to do. Better, if circumstances permit, to move them to forward bases – including offshore installations – where they can shut down and wait for taskings.

3.9 In all cases regarding aircraft deployment, the SMC should seek the advice of aeronautical SAR experts as necessary, especially the ACO. The ACO is also responsible for offering unsought advice to the SMC and/or OSC if SAR aircraft taskings are inappropriate or the aircraft can be better used. See guidance paper 4.5.

4 IAMSAR Guidance

4 IAMSAR Guidance

4.1 As noted above, the IAMSAR Manual, especially Volumes II & III, is the primary source of guidance on SAR aircraft operations. IAMSAR Volume II says , in the context of mass rescue operations, that:

Chapter 6.15.24-25.

“Helicopter capabilities should be used if available, especially for retrieval of weak or immobile survivors. Lifeboat crews should be trained in helicopter hoist operations. Lowering a rescue person from the helicopter to assist survivors may be viable.

“Ship companies should be encouraged to equip large passenger ships and possibly other types of vessels with helicopter landing areas or clearly marked hoist-winch areas to facilitate direct transfers.”

4.2 While landing areas may be limited, marked winching areas, clear of obstructions, should be prepared and joint training opportunities should be encouraged, to the benefit of both ships’ and helicopter crews. IAMSAR Volume III should be consulted as regards all aspects of ship / helicopter operations. See also guidance papers 5.1 & 5.3 as regards training and exercises.

4.3 IAMSAR includes the following comment on the number of SAR aircraft required:

Volume II, chapter 7.1.3.

“In any SAR operation, SMCs should consider the capabilities and the number of aircraft required. Too few aircraft in an operation might prove fatal for persons in distress, while too many can be difficult to organize and increase the risk of collisions. Other factors that might affect the number of aircraft required include the number of casualties, the carrying capacity of participating aircraft, weather conditions on scene, the distance of persons in distress from rescue facilities, the number of evacuation points, the speed at which an evacuation can take place, the speed of participating aircraft, the availability of refuelling facilities, the duration of an operation, aircrew fatigue and other operational factors. Where more aircraft than needed are available some can be held in reserve.”

4.4 On aircraft capabilities and SAR planning IAMSAR says:

Volume II, chapter 7.1.4 & 7.1.6 and Volume III, Section 5.

“SMCs should consider how to match different aircraft capabilities to the circumstances and tasks required. For instance, fixed-wing aircraft might be excellent communications platforms and able to carry out searches and ACO duties, but are not capable of rescue hoist operations. SAR helicopters are flexible in their operations, but usually cannot fly as fast, as far, or as high as fixed-wing aircraft and generally need to refuel more often. Remotely Piloted Aircraft (RPA) might have useful reconnaissance and communications capabilities and be able to remain on scene for long periods of time, but some RPA also have a limited radius of operations. In general, for safety reasons, aircraft flown by aircrew and RPA should be kept well apart. [...]

“SMCs should consider the abilities of the crew and aircraft when planning and during operations, so that no tasks are beyond their abilities.”

If tasks are given that would require aircraft and aircrew to conduct flying activities “beyond their abilities or their approved types of operations [...] the pilot-in-command shall inform the RCC/OSC/ACO immediately.”

4.5 The SMC, working closely with the OSC and ACO,

“should aim to achieve the most effective blend of aircraft and surface unit capabilities for the situations that are anticipated. The operation should aim to achieve continuous or efficient use of aircraft on scene when needed, while minimising the situations in which aircraft are airborne without a mission.” Aircraft held in reserve “can provide additional resources if needed, or relieve other aircraft involved in the operation for reasons related to aircrew fatigue or maintenance requirements.”

IAMSAR Volume III, Section 5.

4.6 Good communication and understanding between SMC, OSC and ACO, and between the ACO and the pilots-in-command of the aircraft responding to the incident, are essential to flight safety and operational success. The coordination of multiple aircraft responding to an MRO is a specialist subject which the text added to IAMSAR deals with in detail, and for which potential ACOs should be specifically trained. See guidance paper 4.5.

4.7 The new IAMSAR text also includes guidance on the reporting necessary to the ACO’s and aircraft commanders’ situational awareness; on refuelling; and on entering and leaving ‘areas of SAR action’.

IAMSAR Volume III, Section 5 defines an ‘area of SAR action’ as “an area of defined dimensions that is established, notified or agreed for the purposes of protecting aircraft during SAR operations and within which SAR operations take place”.

“SAR aircraft intending to enter an area of SAR action should normally first contact the ACO. They should not enter the area until the ACO gives them permission and provides them with sufficient information to safely join the flow of SAR aircraft involved in the operation. [...]

“Aircraft that are not involved in a SAR operation should normally not fly within areas of SAR action. However, if such aircraft need to enter an area of SAR action, they should do so only with the approval of a SMC, ACO or coordinating ATS unit and are subject to the rules of the area or the relevant class of airspace. If a SMC or coordinating ATS unit is giving approval, the ACO should first be consulted.”

5 Summary

5 Summary

o   Winch-fitted maritime SAR helicopters are a major aid to maritime rescue generally and will certainly have a place in a mass rescue operation – but their best use should be carefully considered. They are probably best thought of as 'specialist' rescuers in MROs, providing 'surgical' delivery and extraction services.
o   Fixed-wing SAR aircraft may be able to deliver support; can cover search areas rapidly and effectively, and make good communications and surveillance platforms. A fixed-wing aircraft with a SAR-trained crew is likely to be the best choice as ACO in areas not covered sufficiently by Air Traffic Services.
o   The SMC, working with the OSC and the ACO in particular, should aim to achieve efficient use of aircraft on scene when needed, minimising situations in which aircraft are airborne without a mission. Where more aircraft are available than are needed immediately, some can be held in reserve at forward bases.
o   Good communication and understanding between SMC, OSC and ACO, and between the ACO and the pilots-in-command of the aircraft responding to the incident, are essential to flight safety and operational success. All aircraft intending to enter the area of SAR action should do so only with the agreement and under the control of the ACO.
o   The IAMSAR Manual should be consulted, and other guidance papers in this series considered, as regards different parts of the operation; search, rescue, support, coordination and communications.

6 Further Reading

6 Further Reading

6.1 For further reading on command, control, coordination and communications in mass rescue operations, follow this link.

6.2 The reader is also referred to the other guidance papers mentioned in the 'Overview' above and, in turn, to the further reading they recommend.

6.3 In general, the IAMSAR Manual provides the main international guidance on the use of SAR facilities; Volume II as regards their choice and coordination, and Volume III as regards their operation.

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