Communication problems

can be caused by a number of reasons

There are two types of communication failure- one-way communication failure and two-way communication failure.

One-way communication failureis a situation when either a pilot or a controller is unable to transmit or receive a message.

Two-way communication failureis a situation when both pilot and controller are unable to transmit and receive a message.

In the event of one-way communication failure (i.e. aircraft can receive only), the controller may request the aircraft to make identifying turns, flash its navigational lights, transmit codes or IDENT signals on the transponder, rock its wings, etc, to acknowledge clearances or instructions

When it is known that two-way communication failure has occurred, ATC shall maintain separation between the aircraft having the communication failure and the other aircraft based on the assumption that the aircraft will operate in accordance with VMC or IMC.

In the event of any (one-way or two-way) radio communication failures the pilot-in-command shall

1) use all available facilities, take measures to re-establish communication with the ATC directly or by means of other aircraft. In such cases, if necessary, the emergency frequency 121.5 MHZ may be used.

2) transmit position reports and intentions, assuming the aircraft transmitter is operating, and prefixing all transmissions with “TRANSMITTING BLIND”.

3) turn on landing lights, beacons, and strobe lighting.

Adherence to the appropriate RCF emergency procedures depends on the flight conditions - VMC or IMC.

In VMC:

Pilots shall

· set transponder to Code 7600

· continue to fly in visual meteorological conditions

· land at the nearest suitable aerodrome

· report the arrival by the most expeditious means to the appropriate air traffic control unit .

In IMC

1) Crew has to set squawk 7600, maintain the last assigned speed and level, or minimum flight altitude if higher, for a period of 7 minutes following the aircraft’s failure, to report its position over a compulsory reporting point and thereafter adjust level and speed in accordance with the filed flight plan;

2) In the event of radio communication failure directly after take-off, the pilot-in-command shall carry out approach according to the established pattern and land at the departure aerodrome.

3) If it is impossible to land at the departure aerodrome after take-off (due to meteorological conditions or if the aircraft mass exceeds the landing mass and fuel jettison is impossible etc.), the pilot-in-command has the right:

a) to proceed to the destination aerodrome according to flight plan. Complete a normal instrument approach procedure as specified for the designated navigation aid or fix; and

land, if possible, within 30 minutes after the estimated time of arrival

b) to proceed to the alternate aerodrome at the flight level assigned by the ATS unit or at proximate lower flight level (in accordance with vertical separation rules), but not below minimum safe flight level.

ATC will consider aircraft experiencing communication failure if the expected report is missing within 5 minutes.

Firstly, it is necessary to call the aircraft on definite frequencies (on current and previous sector frequencies) and identify whether it is one-way communication failure or two-way communication failure.

If an identified aircraft experiences a radio failure, the radar controller shall instruct the aircraft to make a turn(s) or set another transponder code. If movements of the plane or another code indicate that the aircraft receiver is operating the controller shall continue to pass instructions blind and twice. Supervisor has to be informed and engineer has to be invited to check the equipment.

After attempts to establish normal two-way radio communication have failed, controllers are to carry out the following standard radio failure procedures:

• Maintain separation between the radio failure aircraft and other known traffic;
• When operating in RVSM airspace, provide a minimum vertical separation of 2000

feet between the radio failure aircraft and any other aircraft;

• Give pertinent information about the movements of the radio failure aircraft to

other aircraft in the presumed vicinity;

• Ask aircraft in the presumed vicinity to establish communication with the radio

failure aircraft and relay messages;

• Use all means possible to monitor the aircraft’s progress;
• Transmit, on the appropriate frequencies:

• level, route and EAT (or ETA) to which the radio failure aircraft is assumed to be

adhering;

• the weather conditions at the destination aerodrome, a suitable alternate and, if

practicable, in areas suitable for a descent through cloud.

• When, in consultation with the operator, instructions to divert have been transmitted to the radio failure aircraft, inform the alternate aerodrome and request that they attempt to establish communication.

During flight without radio communication at night, the crew shall, if possible, indicate aircraft position by periodical switching on onboard landing lights or by onboard lights flashing.

In order to avoid miscommunication both pilots and controllers have to

• Pronounce each word clearly and distinctly
• Maintain an even rate of speech (not exceeding — typically — 100 words per minute)
• Make a slight pause preceding and following numerals; this makes them easier to understand
• Maintain the speaking volume at a constant level
• Be familiar with microphone-operating techniques (particularly in maintaining a constant distance from the microphone)
• Usage of standard phraseology (non-standard phraseology, garbled phraseology or the omission of key words may change completely the meaning of the intended message, resulting in potential conflicts)

The most significant example is the North American phrase “Taxi into position and hold.” It has the same meaning as the ICAO phrase “Line up and wait,” whereas the ICAO phrase “Taxi to holding position” is a clearance to taxi to and hold at a point clear of the runway. Always read back the necessary clearances:

√ ATC route clearances

√ Clearances and instructions to enter, land, take off, hold short of, cross or

backtrack on RW

√ Runway in use

√ Altimeter setting

√ ATC transponder code

√ Altitude or flight level instructions

√ Heading and speed instructions

√ Transition levels

· Undergo constant enhanced training as for communication for situational awareness

Miscommunication can cause RW incursion.

Runway incursion is called "Any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of a surface designated for the landing and take-off of aircraft".

We can speak about typical scenarios of RW incursion:

· Controller-related situation: not having visual contact with the aircraft due to poor visibility controller instructs one plane to clear the RW but pilots misunderstand the instruction or appear on the RW by mistake and without checking their position ATC clears another aircraft for take-off.

BIRD STRIKE

A BIRD STRIKE is a collision between a bird or flock of birds and an aircraft in flight or on a take-off or landing roll. The term usually covers other wildlife strikes - with bats or ground animals. It is a common threat to aircraft safety and has caused a number of fatal accidents.

Different factors can affect the likelihood of the bird strike:

1. Location of the airport (the risk of the bird impact is higher if the airport is located close

to the water surface - seas, rivers, lakes, residential area,

city rubbish dumps, breeding places, agricultural fields as these

places attract the birds)

1. Season of the year (there is high hazard during spring and autumn as it is migration time)
2. Time of the day (birds activity is more intensive in the morning when they rush to the

breeding place and in the evening when they come back)

The seriousness of the bird strike depends on

• The size of the bird (The bigger the bird, the bigger the damage it causes to the aircraft. Small birds simply die when they collide with the airplane, and the airplane moves on. Big birds can damage some parts of the airplane, which may endanger the flight.)

• The speed of the aircraft on impact (If it happens on the ground while taxing when the speed of the plane is low, the effect of the impact will be minimum, if the aircraft encounters the birds at cruising level or during rolling for take-off when the speed is higher, the damage of the plane will be more serious.)

• The phase of the flight (The majority of the strikes happen during take-off, landing or approach phase.)

Day to day flight altitudes for most birds are in the range from the ground to 500 feet. Though great number of bird strikes occur till 50 feet during landing or take-off. The risk decreases doubly till 500 feet. Outside that range, they rarely exceed 1000 feet except on long distance migration flights. These typically occur at a 5000 - 7000 feet altitude, but geese have sometimes been detected at over 20000ft.

• The place of impact

The most vulnerable parts of the aircraft are

• Windscreen
• Engine

In case of bird strike on windscreen it can cause windshield dirtiness that can lead to deterioration of view. In some cases the windshield can crack due to bird strike and it will lead to communication problems due to wind blast and sometimes pilots’ incapacitation or depressurization.

In case of bird strike on engine it can cause engine surge (as the blades may be distorted) or flame out (as bird’s feathers may ignite or crippled blades may be sucked into a compressor and damage it) and as a result impairing flying characteristics of the aircraft. Bird strike can also cause engine failure and create an emergency. Depending on how many engines are affected by the birds it may make levels and heading difficult to maintain or even forced landing outside the airport or ditching.

Another damage from the birds impact can be to extended landing gear assemblies in flight. It can lead to sufficient malfunction of brakes or nose gear steering systems and cause directional control problems during a subsequent landing roll.

Thus, the bird strike can result in

• Broken Windshield/Canopy
• Engine Failure (multi-engine)
• Engine Failure (single engine)
• Hydraulic Problems
• Handling Difficulties
• Electrical Problems
• Gear Problems

Birds that can pose risk to the aircraft in our region are

• Gulls
• Seagulls
• Sparrows
• Swallows
• Crows
• Geese
• Ducks
• Eagles
• Falcons
• Owls
• Pigeons
• Partridges
• Cranes
• Starlings
• Tomtits

The opportunities to mitigate the risk of hazardous bird strikes are centered on airports, because this is where the majority of strikes occur.

In order to prevent bird strikes different precautions can be used

1. Habitat management, including reduction or elimination of trees, shrubs and other plants which provide food, shelter or roosting sites for birds.
2. Cooperation with local authorities to ensure that landfill waste disposal sites are not operated so as to create an aircraft hazard.
3. Cooperation with local farmers to limit the attraction of birds to fields.
4. Use of bird scaring techniques at the airports such as:

• Usage of sound systems emitting high frequency sounds or cries of birds of prey
• Constant vigilance by special airport services which have to inspect the RW
• Switching on landing lights by pilots
• Usage of signal rockets for chasing the birds away
• Usage of cow scares
• Usage of specially trained falcons for scaring the birds away
• Keeping the grass near the RW cut so that birds can not settle there

DEPRESSURIZATION

Depressurization is a rapid loss of atmospheric pressure due to damage of fuselage construction when the air inside the aircraft becomes as thin as outside and thus not appropriate for breathing.

Pressurization problems can be caused by:

· Technical reasons (malfunctioning of the air-conditioning system, electrical system

failure, engine failure because engine supplies the work of air

conditioning system , metal fatigue, glass fatigue)

· Outside factor (bird strike on a windscreen at high level, detachment of engine that can

damage the fuselage, encountering adverse weather conditions, such as

severe turbulence, lightning strike that can cause significant damage of

the construction of the aircraft)

· Human factor (explosion of bomb, shooting, not properly closed door, poor

maintenance before departure)

Any damage to the system could result in a leakage and consequently a rapid loss of cabin pressure.

Pressurization problems can cause an immediate danger to the aircraft, as the reduction of the cabin pressure will affect the crew and the passengers. The time during which people can retain consciousness without oxygen depends on the altitude flown, the size of the oxygen leak and the dimensions of the fuselage . It can vary from 4 to 30 seconds.

There are two types of depressurization: rapid (explosive) and slow (gradual).

ENGINE FAILURE

Engine failure may be caused by:

· Technical reasons( √fuel system problems such as fuel contamination, fuel leak, fuel exhaustion, fuel control system malfunction, wrong fuel calculation;

√ hydraulic system failure;

√ electrical system malfunction;

√ high or low oil pressure

√ metal fatigue-demolishing of pylon which

attaches engine to the wing)

· Weather conditions(icing , hail storm that can impair the work of engine or lead to its stall; volcanic ash- volcanic pieces of rock get into engine, melt, stick to the compressor and cause flame out or failure, lightning strike )

· Human factor (pilot’s error- e.g. shutting down running engine by mistake due to stress or high work load; poor maintenance service on the ground)

· Outside factor (bird strike on the engine – depending on the size of the bird it can cause blades damage; overheating due to ingestion of a foreign object or debris on the RW)

There are various engine problems:

√engine cut off

√engine fire

√high vibration

There are two types of engine failure

- “contained” engine failure means failure when components might separate inside the engine but either remain within the engine or exit the engine through the tail pipe.

- “uncontained” engine failure canpose a greater risk as ejected debris from the engine exit it at high speeds in other directions, posing potential danger to pressurized aircraft structure.

Consequences.

The consequences of an engine failure depend on the number of engines the aircraft has.

Multi-engine aircraft. The loss of one engine on a multi-engine aircraft will reduce its power and the ability to fly normally:

• High altitudes, above FL 200, may not be maintained
• Turns to the side where the engine has failed need to be wider not to get into stall and are expected to be slower
• Propeller driven aircraft may descend to increase speed and maintain cabin pressure
• Heavy workload in the cockpit will restrict the pilot’s ability to communicate with ATC
• Long and high speed approach and landing (due to performance limitations attributed to the engine failure the approach speed might be higher than prescribed, which could consequently result in non-established approach, runway excursion and blocked runway)

Single-engine aircraft. The engine failure of a single-engine aircraft will be followed by

· loss of electrical power

· loss of navigational systems

· loss of communication systems

· loss of cabin pressure

· manual gear extension

In case of engine failure during rolling, take-off should be aborted if it occurred before V1 speed, and after a complete stop the situation should be reported to ATC.

If it happened after V1 speed the crew must

• ∙ perform take-off
• ∙ climb 400 feet minimum and apply ECAM procedure
• ∙ level off the aircraft
• ∙ retract slats and flaps
• ∙ set idle mode for affected engine
• ∙ set full power thrust for running engine
• ∙ make turn and perform landing.

Deviation from SID may be expected - if the engine failure occurs at take-off or after rotation, the crew might not follow the published SID and any associated noise abatement procedures.

It is possible to expect:

• Aircraft may not follow initial departure clearance - it may continue straight ahead or follow its own emergency turn procedure.
• A stepped climb may be required to retract high lift devices.
• A larger radius of turn can be expected due to reduced aircraft performance and maneuverability.
• The flight crew may experience other handling difficulties. For example, turns in one direction may be preferred.
• The flight crew may elect to dump fuel.
• A longer landing distance may be required.

In case of engine failure on multi-engine aircraft at cruising level the crew has to increase power on running engine, shut down affected engine, analyze the situation, attempt to restart the engine (if they are sure there is no fire) and decide whether to fly to the nearest alternative or to proceed to the destination (if fuel amount permits as they will fly at lower altitude and it will result in more fuel consumption).

The aircraft will maintain the lower levels in order to restart affected engine or APU. If the crew decided to restart the engine, necessary increase of speed is provided by descending. Sometimes total engine failure may result in depressurization as air conditioning system is supplied by engines. In this case emergency descent without notifying ATC may be expected.

In case of engine failure on single-engine or multiple engine failure on multi-engine aircraft pilots need to start gliding. The crew will seek the best glide ratio in order to attempt to restart the engine(s) and/or to reach next suitable aerodrome/airfield or a place suitable for emergency landing. In this case approach speed may be higher than prescribed, landing distance may be increased. So, this situation can cause

• RW excursion
• Rough landing

ATC has to

• Evaluate the situation (receive pilot’s report as for emergency: reason and consequences, remind pilots to set squawk 7700)
• Clear the air space below the affected aircraft
• Impose radio silence, if necessary
• Provide safe separation with the other aircraft in this sector
• Inform supervisor and military services
• Inform landing aerodrome, alert emergency services
• Inform the nearest to destination airport (in case the route is changed)
• Request the information concerning changes on board
• Clear RWY when ACFT 50 track kilometres from touchdown

• Keep safety strip clear

• Offer pilot extended final
• In case of emergency landing request if there is dangerous cargo and flammable goods on board and POB

• In case of forced landing outside the airfield, record last known position and time and alert rescue teams

If needed, inform the crew about next suitable aerodrome and provide alternate aerodrome details (RWY in use, length, surface, elevation, ILS- and NAV-frequencies) and weather information.

Inform landing aerodrome of the inbound traffic with engine failure

ATC has to keep in mind that due to engine failure on multi-engine aircraft work load on the crew increases, as they have to perform emergency procedures. So, controller may be informed with some delay and radio communication will be resumed after report of the crew.

FIRE ON BOARD

Fire is one of the most hazardous situations as it spreads rather quickly. According to statistics crew of affected aircraft has only 17 minutes to initiate emergency descent, to perform emergency landing and to evacuate the passengers. Otherwise,without aggressive intervention by the flight crew, the aircraft will burn out to ashes.

Causes

Fire may be caused by a number of reasons:

• technical problems (electrical system malfunction, electrical short circuit, ignition of dangerous easy-flammable goods during transportation)
• outside factor (lightning strike, hail, severe turbulence, bird or debris ingestion into the engine)
• human factor :

√ Passengers’ error. Most carriers prohibit smoking on board the aircraft. This, coupled with the use of fire resistant materials, has reduced the likelihood of fire caused by a cigarette. Nevertheless, despite it minority of passengers continue to smoke in the lavatories. Thus, not extinguished cigarette can pose risk to the safety. Explosion of bomb by terrorists can obviously lead to fire.

√ Cabin crew error. Airlines comment that most in-flight and ground fire/smoke events relate to the galley and involve some kind of electrical equipment. Oven fires may occur because of items (which are not heat resistant) being placed inside the oven by FAs (e.g. oven being used as storage place for folders or checklists, or to dry shoes) or because of overheating, or electrical overload/short circuit. In addition to ovens, there is a lot of equipment in the galley wrong usage of which can cause fire (e.g. coffee or water heaters on without any water in).

√ Airport security officers’ error. Overhead compartment fire is often caused by passengers’ hand luggage which was not thoroughly checked (e.g. nail polish remover, medicinal or toilet articles, matches, and other prohibited items).

√ Flight crew’s / loaders’ error. Loosely packed dangerous goods (which are not thoroughly controlled by pilots) by loaders can ignite due to friction.

The International Civil Aviation Organization defines Dangerous goods as “ articles or substances which are capable of posing risk to health, safety, property and the environment.”

Dangerous goods fall into 9 classes:

• Class 1: Explosives –Explosive substances, explosive articles, and pyrotechnic

devices, for example, ammunition, and fireworks.

• Class 2: Gases
• Class 3: Flammable liquids –Examples are petrol, alcohol, and perfume.
• Class 4: Flammable solids –Examples are matches, flammable metal powder.
• Class 5: Oxidizing Agents and Organic peroxides

These substances are sensitive to impact or friction, or may create a dangerous reaction when in contact with other substances. They may be explosive and burn rapidly. Some examples are fertilizers and chemicals.

• Class 6: Toxic (poisonous) and infectious substances

These substances can cause death or injury if swallowed, inhaled or absorbed through the skin. Examples are pesticides and poisons, mercury.

• Class 7: Radioactive materials
• Class 8: Corrosives.
• Class 9: Miscellaneous- Hazardous substances such as dry ice and magnets.

Dangerous goods fall into three types:

1. Goods that are acceptable on passenger and cargo aircraft
2. Goods that are acceptable on cargo aircraft only
3. Goods that are prohibited for air transportation

Goods which are strictly prohibited for transportation in the cabin are

• Explosives - fireworks, flares, toy gun caps

• Compressed gases - filled or partly filled aqualung cylinders

• Flammable liquids and solids - lighter fuel, matches, paints

• Oxidizers - some bleaching powders

• Poisons

• Irritating materials - tear gas devices

• Infectious substances - live virus materials

• Radioactive materials - medical or research samples which contain radioactive

sources

• Corrosives - acids, etc.

• Magnetized materials - instruments containing magnets

Consequences

Fire on board can result in

· High stress level in the cockpit

· Engine failure

· Pressurization problems

· Shortest high speed vector to land

· Poor R/T (due to oxygen mask) or loss of R/T

· Passengers’ evacuation

· RWY blocked

Types of fire

Engine fire.

Engine fire is normally detected and contained satisfactory by the aircraft fire detection and suppression systems. But there are such situations when fire can not be determined by onboard systems and it can spread to the wing and the fuselage. Even when engine fire was eliminated, the crew need to land the aircraft as soon as possible so that the fire will not break out again.

Cabin fire.

Cabin fire can be easily detected and put out by usage of fire extinguishes. It is also advisable to perform landing as soon as possible in order to investigate the problem.

Hidden fire.

Hidden fire can be detected by onboard systems or by passengers noticing smoke or fume. It is very hazardous as smoke can fill up the cabin and can reduce visibility and lead to suffocation and choking.

Effects

At the first indication, or suspicion, of smoke and fumes, or fire within the aircraft the flight crew will don smoke goggles and oxygen masks. The wearing of oxygen masks may make the voice messages more difficult to understand.

Secondly, the crew will attempt to find the source of the smoke or fire and eliminate it. Different emergency equipment may be used, such as smoke detectors, fire extinguishes, fire gloves, fire goggles, hoods, crash axe, emergency chutes for evacuation.

• Smoke detectors. Optical Smoke Detectors are installed in aircraft toilets and usually in cargo compartments as well. They are usually only activated by a significant reduction in visibility due to thick smoke from, say, a waste bin fire. Cigarette smoke will not usually activate them.
• Portable fire extinguishers. Portable extinguishers are to be found in the cockpit and in the cabin. They are designed to fight with small fires and thus their capacity is limited.
• Fire/crash axe. Fire axes are provided to obtain emergency access to areas and parts of the airplane which are not easily accessible (e.g. behind sidewall, electrical or ceiling panels).
• Fire protection gloves. These gloves are kept in the flight deck and/or in the cabin to protect the user against heat/fire. They can also be used to handle hot or sharp objects.
• Smoke hoods. It is a smoke protective device which incorporates a small oxygen generator, which provides the user with oxygen for a limited amount of time, typically 15-20 minutes.
• Smoke goggles. Smoke goggles may be found in the flight deck for use with smoke hoods. Some aircraft are equipped with oxygen masks with integral smoke goggles.
• Fire Blankets. Some operators have fireproof blankets on board which can be used to suffocate fire by cutting off the supply of oxygen.

When crew members manage to extinguish fire, the captain will evaluate the situation and make up his mind what further actions to take. But in the majority of cases he’ll give preference to land as soon as possible for further investigation if any systems were affected by fire.

If fire is uncontrollable and pilots will

-put oxygen masks on if there is smoke or fire in the cockpit

-initiate emergency descent without any delay (otherwise it will take an aircraft a few

minutes to burst into flames and burn fully)

-set squawk 7700

-declare Mayday

- proceed to the nearest suitable airport and request priority for landing or

- try to find an appropriate place for landing ahead of them (off-field landing or ditching)

- request fire brigade, ambulance, search and rescue team

- upon landing start immediate evacuation of passengers (After disembarkation for safety reasons they have to be removed on 100metres distance from a crippled aircraft.)

If there is engine fire, pilots need to

- increase the work of running engine

- shut down affected one

- activate fire extinguishing system

- stop fuel and hydraulic liquid supply

- close air conditioning supply from the engine

- start APU for auxiliary electrical power

- start emergency descend

- set squawk 7700

- declare Mayday

- proceed to the nearest suitable airport

ATCneeds to act quickly

• Evaluate the situation (receive pilot’s report as for emergency: reason, consequences)
• Provide safe separation with other aircraft in this sector
• Request pilots to set squawk 7700
• Impose radio silence if necessary
• Inform supervisor and military services, alert military services

• Give aircraft priority for landing
• Ask if dangerous goods are on board
• Ask for number of Persons On Board (POB)
• Inform landing aerodrome
• Clear RWY when ACFT 50 track kilometres from touchdown
• Keep safety strip clear
• In case of diversionary or forced landing, record last known position and time
• Alert emergency services

If needed, inform pilot about:

• Next suitable aerodrome
• Aerodrome details as soon as possible

RWY in use, length, surface, elevation, ILS- and NAV-frequencies

• Weather information of landing aerodrome
• Observe fire and/or smoke in order to help pilots to make decision from what side it is better to start evacuation of passengers (if required).

ATC has to be aware of:

1. In case of fire a flight crew does not have very long time for communication - time is critical. The crew will commence descent immediately and begin planning an emergency landing possibly without controller’s clearance

1. Putting an aircraft on the ground within 15 minutes of a fire being detected is a challenge for the pilot of a modern passenger jet at cruising altitude, so expect the descent to be rapid.

1. After the initial emergency call, and having declared their intentions, the crew will turn their attention to isolating and fighting the fire, and may therefore not respond to calls. The controller will need to be patient and try to anticipate the actions of the flight crew and not to press them with non-urgent questions.

FUEL PROBLEMS

Fuel system is of vital significance for the safe completion of the flight. Without fuel supply the engines will cease operating and without the power produced by the engines the aircraft can not be in the air. Thus, fuel system is of paramount importance.

Fuel problems may be caused by variety of factors:

• Adverse weather conditions

√unexpected severe headwind ( it reduces the speed and increases fuel consumption;

so, the fuel remaining may become critical and not enough for reaching the

destination)

√ encountering thunderstorm activity zones ( so, circumnavigation of the areas with

CB clouds and diversion to an alternate aerodrome may result in fuel shortage)

• Technical problems presuppose different system malfunctions

√ deficiencies in pipe and pump systems ( which can result in fuel leakage)

√ fuel gauge/ fuel measurement system failure

√ fuel consumption system failure

√ fuel contamination with ice, water or metal chips and as a result blocking of fuel

filters

√ metal fatigue (that can lead to fuel leak)

√ low pressure in the system

• Human factor contains

√ wrong fuel calculation (due to various measuring systems which use different

measuring units, e.g. litters, pounds, gallons)

√ fueling the aircraft with not appropriate quality of fuel

√ poor maintenance service on the ground (when the technical staff forgets to close

the fuel filler and pilots fail to check it; foreign objects appear in the fuel due to

negligence of ground personnel)

√ pilot’s error in feeding the engines with fuel during the flight

√ pilot’s mistake (e.g. going around due to missed approach)

√ ATC’s mistake (e.g. keeping the aircraft in holding pattern for considerable time,

for example due to government flights etc.)

Effects:

Fuel problems may occur due to any contingency and have multiple side effects, possibly impairing the pilots’ ability to fly and land the plane safely. Without fuel one or both engines can be expected to fail, which may in turn result in a forced landing short of the RW or short of the airport itself.

There are various fuel problems such as fuel leak, fuel starvation, fuel exhaustion, fuel contamination.

In case of fuel leak pilots need to stop fuel supply from the affected tank in order to prevent ignition. Fuel exhaustion can result in engine failure as it can’t operate without fuel. If there is exhaustion only in one tank, cross feed fuel procedure will take place (fuel from one tank will be transferred to another in order to eliminate fuel imbalance).

Fuel exhaustion- is situation when the aircraft runs out of fuel completely and the tanks are

empty that leads to engine failure. It is considered to be an emergency situation.

In this case forced landing outside the aerodrome(or ditching) is possible. Radio

vectoring to the nearest aerodrome is recommended.

Fuel starvation- is situation when there is fuel in the tank but there is a supply problem which

either fully or partially prevents the fuel from reaching the engine. Causes may

include a blocked fuel filter or more commonly water-contaminated fuel. In this

situation pilot is not sure that remaining amount of fuel will be enough for

safe completion of flight. He can switch off the fuel pumps on affected tank and

supply both engines from another tank.

Fuel imbalance – is the situation when the remaining of fuel in one fuel tank is bigger or

smaller than in another. In this case pilots have to assess the situation ( as the

the engines may consume different amount of fuel due to age or some other

parameters) . So, the crew checks the reason of imbalance. If there is no fuel

leak, cross-feed fuel procedure has to take place in order to equalize fuel

(the fuel from one tank is transferred to another). But if there is a suspect of fuel

leak, it is possible to supply both engines from one tank .

Fuel contamination- is a situation when there is water, metal chips or some other foreign objects

in the fuel. It can lead to engine failure, not stable work of the engine,

fuel system failure, possibly forced landing out of aerodrome or

ditching. There are different forms of contamination that can exist.

For example:

- bacterial

- microbial

- foreign object

- water

- dirt

- sand

- ice

In cases when maximum landing weight of the aircraft is exceeded, fuel dumping or fuel burning are required.

Fuel dumping (or a fuel jettison) is a procedure used by aircraft in certain emergency situations before a return to the airport shortly after take-off, or before landing short of its intended destination to lighten aircraft's weight.

Special dumping area should be requested and entered.

More sophisticated aircraft are not equipped with fuel dumping system. Thus, only fuel burning is possible.

Sometimes in-flight refueling may take place.

In-flight refuelling is also called air-refuelling, air-to-air refuelling or tanking, is the process of transferring fuel from one aircraft (the tanker) to another (the receiver) during flight.

This procedure allows the receiving aircraft to remain airborne longer extending its range or loiter time on station, it also gives opportunity to the aircraft to take off with bigger amount of cargo as less fuel is carried while take-off and the plane is topped up when in the air.

The first in flight refueling took place in 1949 when American plane B50 performed the first non-stop flight around the world which took 94 hours. It was possible due to air- refueling.

At this moment in-flight refueling is used only for military aircraft.

In case the crew faces with fuel exhaustion or fuel leak, pilots immediately have to identify the source of the problem and eliminate it, if it’s impossible - notify ATC, declare an emergency and request priority for landing at the nearest airport. If they can’t make it to the airport, they have to perform landing ahead of the aircraft at any suitable surface (ditching may be possible).

If critical fuel status is reported to the ATC, his actions include the following

• Ask if the crew declares emergency
• Clear the air space below the affected aircraft
• Provide safe separation with the other airplanes in this sector
• Impose radio silence ( if necessary)
• Keep ACFT high (in order to save fuel)
• Inform landing aerodrome and emergency services
• Ask if dangerous goods on board
• Ask for number of Persons On Board (POB)
• Offer out of wind landing if more expeditious
• Clear RWY when ACFT 50 track kilometres from touchdown
• Keep safety strip clear

If needed, inform pilot about:

• Next suitable aerodrome
• Aerodrome details as soon as possible

ATCs don’t have to press the crew with non-urgent questions at this time.

MEDICAL EMERGENCY

Onboard Medical Emergency is an acute health problem that can pose great risk to the occupant’s life. If the emergency is serious enough and can not be treated with onboard equipment and medical substances, immediate diversion is required.

The most common medical emergencies are

• Heat attack
• Cardiac arrest
• Epileptic seize
• Severe allergic reaction
• Diabetic episode
• DVT (deep vein thrombosis)
• Asthma
• Poisoning
• Decompression sickness
• Baby delivery
• Severe injuries/ limb fractures

Contributing factors to the development of medical emergency during a flight are

- travelling of elderly people (over 70-75)

- travelling of people with chronic diseases (heart problems, asthma, epilepsy, blood pressure problems. Time zone changes and altered meal times can result in insulin dependent diabetics becoming hypoglycemic, though diabetic meals can be provided. Passengers on other strict drug regimens, such as epilepsy, may also have problems, especially if they have packed their medication in the hold. )

- travelling of pregnant women ( in the late months of pregnancy)

- alcohol abuse

- long range flights (DVT can develop due to long time motionless sitting in restricted room )

- unexpected severe turbulence (falling objects from overhead storage bins can lead to injuries)

- fear of flying

- stress (the stress of getting through a modern airport security checks, stress due to flight delay)

Each aircraft is equipped with first aid kit and medical emergency kit.

The first-aid kit is accessible to the flight attendants and generally includes:

• Bandage
• Adhesive plaster
• Antiseptic swabs
• Thermometer
• Inhalers
• Blood pressure cuffs
• Arm and leg splints
• Iodine
• Light pain killers
• Ammonia spirit

The medical emergency kitis carried on the aircraft sealed and has to be used only by medical professionals as it contains serious drugs. It usually includes:

• Stethoscope
• Syringes
• Epipens
• CPR masks
• Nitroglycerin tablets for chest pain
• Dextrose solution for hypoglycemia
• Adrenalin for asthma or allergic reactions etc.

One more critical medical emergency is crew incapacitation – inability of a member of the crew to fulfill his/her duties due to physiological factors (sickness, injury, fever or intoxication et c.)

Crew incapacitation may occur as a result of:

• the effects of Hypoxia (insufficient oxygen) in case of depressurization
• the consequences of suffocation due to smoke or fumes in case of fire
• food poisoning
• being asleep
• a medical condition such as heart attack, stroke or seizure or transient mental abnormality
• a malicious or hostile act such as assault by an unruly passenger, terrorist action

Incapacitation generally falls into two groups:

1) Subtle or Incomplete

Skills or judgment may be lost with little or no outward sign.

The person may make illogical actions and decisions, or he/she can manipulate the controls in a hazardous manner.

Subtle incapacitation is most commonly caused by hypoxia, hypoglycemia, extreme fatigue, alcohol, drugs or other toxic substances. Neurological problems, such as stroke or brain concussion, may also be a cause.

2) Obvious or Complete

The first indication of illness may be loss of consciousness, seizures, severe pain or paralysis.

Heart attack or stroke are the most common causes of complete incapacitation. Warning signs include pallor, sweating, nausea, etc.

In case of passenger’s collapse it’s a duty of a flight attendant to assist him with all possible means applying the contest of first medical kit or oxygen mask if necessary. If his condition deteriorates, the cabin attendant reports to the captain and makes announcement if there is any doctor among the passengers. Meanwhile, the pilots have to evaluate the situation and taking into account the company’s policy make decision as for diverting to the alternative in order to save the passenger’s life.

In case of one flight crew member incapacitation a flight attendant should be invited into the cockpit in order to deal with him or her. While another pilot takes over the control of the aircraft, a steward assists a collapsed one. If the pilot fails to regain consciousness, the flight attendant has to move the victim's seat to its full aft position, to recline his seat, to remove his legs from the control pedals, fasten his seat belt with the hands tied up in order to restrain him. Some airlines oblige flight attendants to help the pilot-flying (e.g. reading the check list). So, emergency has to be declared and diversion has to be requested.

To the methods of crew incapacitation avoidance we can attribute:

• Correct use of the aircraft pressurization system and emergency oxygen supplies to prevent Hypoxia and protect the crew from the effects of Smoke and Fumes.
• Therapeutic Oxygen supplies can also alleviate the condition of a crew member or passenger suffering a medical condition.
• Staggering crew meal times and ensuring that each pilot eats different meals both prior to and during flight, will reduce the chance of both pilots becoming incapacitated due to Food Poisoning.
• Proper sleep before the flight.

Medlink

A recent innovation that is used by some airlines is Medlink, a direct communication between the flight crew and an organization where doctors are aware of in-flight medical emergencies and can give an instant help how to deal with this or that case. They also supply the crew with the list of the nearest available airports for diversion where qualified assistance can be provided. This service when being contacted relieves the responsibility from onboard doctor.

Date: 2015-12-24; view: 3583