What measures can be taken to sufficiently decrease the amount of mid air collision

10 Strategies For Avoiding Mid-Air Collisions

1) Remember The Location Of Navigation Lights

Red is always on the left wingtip, and green is always on the right wingtip. A pulsing, red beacon light should be located on the tail of the airplane. If you can remember these lights, you’ll be able to tell which direction an airplane is headed in low light conditions.

For instance, if you see just the green nav light and beacon, you are to the right of the opposing traffic.

2) Verify Which Traffic You’re Following

If you’re flying in a busy traffic pattern, always be careful to ensure you’re following the correct traffic. Making a base turn too early could result in you cutting off another airplane on final if you’re following the wrong traffic.

3) Make Specific Radio Calls

Have you ever heard a radio call and wondered to yourself, «where on earth is that airplane?» Non-specific radio calls leave other pilots confused. Try to be as location-specific as possible by transmitting location, direction of flight, and intentions.

4) Be Careful When Flying To The Side Of Thunderstorms Or Rain Showers

If you’re forced to fly to the side of a heavy rain shower or thunderstorm, so is everyone else. Be extra cautious, as weather can create a funnel for aircraft just like the valleys of a mountain.

5) Always Monitor Local Traffic Frequencies

Traffic-heavy areas often have published advisory frequencies for aircraft to use. Always fly proper VFR altitudes and monitor these frequencies while giving occasional location reports.

6) Use Your Lights

Anything you can do to make yourself more visible to other aircraft is a good thing. While not required during the day, the expense of more frequently replacing a nav light is worth the added visibility. If anti-collision lights are installed, always use them unless you determine its unsafe. Landing lights and pulse lights are also great tools to utilize, especially during takeoff, climb, descent, and landing.

7) If ATC Radar Service Is Available, Use It

If available, requesting VFR Flight Following from ATC is another excellent way to get traffic information. Click here to learn how to use VFR Flight Following.

8) Study Local Traffic Procedures

If you know the local traffic procedures, you’ll have a much better understanding of where traffic density is coming and going.

9) Memorize Right-Of-Way Rules

FAR 91.113 lists out the right of way rules for aerial traffic. Memorizing these rules comes in handy, especially when you need to make a split second decision on which way to turn to avoid another aircraft.

10) If The Traffic Isn’t Moving, You’re Likely On A Collision Course

Have you ever had a close call? Tell us about it in the comments below.

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Mid-air collision

Mid-air collision
Computer-generated image of United Airlines Flight 718 and TWA Flight 2 colliding.

A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually results. The chance of surviving a major mid-air collision is virtually zero in the absence of ejector seats and parachutes, as indicated below, although occasionally this rule may be violated (as on 1965 Carmel mid-air collision).

The potential for a mid-air collision is increased by miscommunication, error in navigation, and deviations from flight plans. Albeit a rare occurrence due to the vastness of open space available, collisions often happen near or at airports, due to the large volume of aircraft and closer spacing compared to general flight.

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First recorded mid air collision

The first recorded collision between air-planes occurred at the ‘Milano Circuito Aereo Internazionale’ meeting held between 24 September and 3 October 1910 in the city of Milan, Italy. On 3 October Rene Thomas of France in an Antionette monoplane collided with Captain Bertram Dickson of the British army in a Farman biplane by ramming him in the rear. [ 1 ] Both pilots survived but Dickson was so badly injured he never flew again. [ 2 ] [ 3 ] [ 4 ]

Efforts to prevent military/civilian collisions in the United States

There are many types and causes of mid-air collisions. On some occasions, military aircraft conducting training flights inadvertently collide with civilian aircraft. Before 1958, civilian air traffic controllers guiding civilian flights and military controllers guiding military aircraft were both unaware of the other’s aircraft. [ citation needed ]

The 1958 collision between United Airlines Flight 736 and a fighter jet, as well as another U.S. military/civilian crash one month later involving Capital Airlines Flight 300, hastened the signing of the Federal Aviation Act of 1958 into law. The act created the Federal Aviation Agency (later renamed the Federal Aviation Administration), and provided unified control of airspace for both civil and military flights.

In 2005, as part of an effort to reduce such military/civilian mid-air collisions in U.S. airspace, the Air National Guard Flight Safety Division, led by Lt Col Edward Vaughan, used the Disruptive Solutions Process to create the See and Avoid web portal. In late 2006, the U.S. Defense Safety Oversight Council (DSOC) recognized and funded the site as its official civil/military midair collision prevention website, with participation by all the services. [ citation needed ]

List of notable civilian mid-air collisions

List of notable military mid-air collisions

See also

References

External links

Look at other dictionaries:

mid-air collision — A collision of aircraft, both of which are in flight … Ballentine’s law dictionary

2002 Überlingen mid-air collision — Bashkirian Airlines Flight 2937 DHL Flight 611 CGI rendering of DHL Flight 611 moments before colliding with Bashkirian Airlines Flight 2937 Accident summary Date … Wikipedia

Porthcawl mid-air collision — Left to right, top to bottom: Katie Jo Davies, Nikkita Marie Walters, Hylton Price, Andrew Marsh Accident summary Date … Wikipedia

1996 Charkhi Dadri mid-air collision — Saudi Arabian Airlines Flight 763 Kazakhstan Airlines Flight 1907 Accident summary Date 12 November 1996 Type Mid air collision caused by pilot error on Kazakhstan Airlines aircraft … Wikipedia

Northwood mid-air collision — Occurrence summary Date 4 July 1948 Type Mid air collision Site … Wikipedia

1972 Lake Winnebago mid-air collision — Accident summary Date 29 June 1972 Type Mid air collision Site … Wikipedia

1956 Grand Canyon mid-air collision — Infobox Aircraft accident name = United Airlines Flight 718 Trans World Airlines Flight 2 caption = Illustrated map of crash location date = June 30, 1956 type = Mid air collision site = Chuar Butte Grand Canyon, Arizona total fatalities = 128… … Wikipedia

First mid-air collision of airliners — Infobox Aircraft accident name = First mid air collision of airliners caption = date = 7 April 1922 type = Mid air collision in fog site = Thieuloy Saint Antoine, Picardie, France coords = coord|49|38|00|N|01|56|49|E|name=Thieuloy Saint… … Wikipedia

1976 Zagreb mid-air collision — plane2 origin = Split Airport Split, Yugoslavia plane2 destination = Cologne Bonn Airport Cologne, West Germany plane2 passengers = 108 plane2 crew = 5 plane2 survivors = 0The 1976 Zagreb mid air collision occurred on 10 September 1976 when… … Wikipedia

1955 Cincinnati mid-air collision — Infobox Aircraft crash date = January 12, 1955 type = Mid air collision site = Boone County, Kentucky total fatalities = 15 total survivors = 0 plane1 type = Martin 2 0 2 plane1 operator = TWA plane1 tailnum = N93211 plane1 passengers = 10 plane1 … Wikipedia

What measures can be taken to sufficiently decrease the amount of mid air collision

This study has been published and translated by the Bureau d’Enquкtes et d’Analyses pour la Sйcuritй de l’Aviation Civile (BEA) to make its reading easier for English-speaking people. As accurate as the translation may be, the original text in French is the work of reference.

OVERVIEW

This study covers mid-air collisions that occurred over French territory between 1989 and 1999, and which involved at least one civil aircraft.

Mid-air collisions involving patrol flights and flying demonstrations are excluded from this study because, in these cases, the pilots knew the position of other aircraft in the air. Collisions between gliders or which involved a parachutist are also excluded from the following study.

From 1 st January 1989 to 30 June 1999, seventeen mid-air collisions were reported.

These collisions caused a total of forty-two deaths and nine injuries. Twenty-seven aircraft were destroyed of the thirty-seven involved.

In three cases, both aircraft involved were able to be flown back to base by their pilots and, in two other cases, one of the aircraft remained flyable through the landing.

Of the seventeen cases studied:

1.1 Distribution by Year

On average, there were 1.5 mid-air collisions per year.

1.2 Pilot Information

1.2.1 Age

The accompanying bar graph shows the various age ranges of the pilots. All those in the cockpit were taken into account.

Note that all the age ranges are affected by mid-air collisions, with an increase up to the 40-50-age range.

1.2.2 Flying Licenses Held

The accompanying pie chart represents the different flying licenses held by the pilots who were in the cockpit during the mid-air collisions studied.

The collisions involved all pilots, regardless of the license they held. The great majority were private pilots. Of the pilots holding a commercial pilot’s license, three involved transport aircraft and the others were instructors.

1.2.3 Flying Experience

The accompanying pie chart shows the overall flying experience of the pilots involved in the collisions, the number of hours logged for each aircraft corresponding to the number of hours flown by the most experienced pilot in the cockpit.

Note that all types of pilots, experience notwithstanding, are involved in mid-air collisions, with a large number having more than 1,000 flying hours (50%)

1.2.4 Recent Flying Experience

Recent flying experience, covering the last three months of the pilot at the controls, was studied. The 90-hour sector corresponds to professional pilots or instructors. The 12-hour sector corresponds roughly to private pilots flying about one hour per week. In seven cases, the recent experience of the pilot at the controls was very low (about one hour per month).

The lack of recent experience, which lowers the outside monitoring of the pilot in the aircraft, is certainly a serious factor. Nevertheless, it is important to note that pilots who fly regularly are not immune to mid-air collisions.

1.2.5 Flight Duration

At the time of the collision, 56% of the planes had been flying for less than 30 minutes, 35% had been flying for between half an hour and two hours and 9% had been flying for more than two hours.

1.2.6 Vigilance

Most events contain factors that can cause a decrease in vigilance:

At this stage of the study, some conclusions can be drawn:

1.3 Information on the Environment

1.3.1 Weather Conditions

All the collisions studied occurred in daytime, while the meteorological conditions were appropriate for VFR flying. It is however necessary to note two cases where the pilots reported poor visibility conditions (end of the day and floating particles in the atmosphere). In six collisions at least one of the pilots had the sun in his face. In three cases the visibility conditions in the air could not be determined.

1.3.2 Aircraft Types

Six of the seventeen accidents took place between a high wing and a low wing airplane. In three of these cases the relative position of the wings (high / low wings) constituted a hindrance for the pilots. It is difficult to draw a general conclusion, but it is certain that dead angles caused by the wing, whatever its position, constitute an important hindrance.

1.3.3 Altitude of Mid-air Collisions

The listed collisions occurred at altitudes ranging from 150 to 8,000 feet.

The accompanying graph shows that these accidents occurred mainly below 3,000 feet. It is in this altitude range that most VFR flights are found. In fact, this corresponds to departures, arrivals and aerodrome circuits, as well as a large number of flights in VFR cruise.

1.3.4 Location of Collisions and Phases of Flight

Seven collisions occurred around an aerodrome. In six cases, one of the two planes was in the integration phase. The seventh accident occurred on the extended centerline. One collision occurred at a controlled aerodrome. Air-to air communication was in force at the other aerodromes.

Eight collisions took place in zones where the concentration of traffic is high (vicinity of aerodrome, overhead a radio navigation device, large number of gliders). Only two mid-air collisions took place during cruise.

1.3.5 Airspace

Twelve collisions occurred in uncontrolled airspace (UA). Three took place in controlled airspace (CA) in which radio contact was not compulsory. Finally, there were two accidents in controlled airspace where radio contact was compulsory.

In three cases, one of the two aircraft was passing from controlled airspace to uncontrolled airspace.

1.3.6 Radio

Of the thirty-four aircraft involved in the mid-air collisions, only one had no radio communication equipment.

We have seen that three collisions took place in controlled airspace in which radio contact was compulsory (two in controlled airspace, the third at controlled aerodrome with uncontrolled airspace). Two others took place at uncontrolled aerodromes reserved for aircraft equipped with radio. Problems were caused by:

Four other accidents took place at aerodromes where radio use was not compulsory. Three occurred during the integration phase. In two of these cases, one of the pilots did not use the radio. In the third accident one of the aircraft had no radio on board.

All these collisions occurred in daytime, in good weather conditions, most often at low altitudes and in zones with heavy traffic. Most took place in uncontrolled airspace or at uncontrolled aerodromes. And finally, radio use was not optimal.

2.1 The See-and-Avoid Rule

The standards and the recommended practices established in Annex 2 of the Chicago Convention, adopted as a national regulation, are applied in French airspace. One of these rules states that:

» Regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft. «

In certain classes of airspace, air traffic control can give information on traffic and clearance in order to prevent collisions, however see-and-avoid remains the basic rule, in VFR as in IFR flights. This rule was obviously not applied correctly in the seventeen cases studied. Several factors hindered its proper functioning.

2.1.1 Review of Sight and its Limitations

Man’s visual perception possesses unique characteristics. It is interesting to study the eye’s structure and function as well as its interaction with the brain in order to analyze possibilities and limitations of sight.

2.1.1.1 Description of the Eye

The front part of the eye is called the cornea, a transparent tissue protecting the eyeball. The iris is the colored part of the eye. In the center of the iris is the pupil that allows light to enter the eye. Behind the iris and the pupil is the lens that changes shape through muscle action. This action enables the lens to focus objects at varying distances on the retina.

The retina contains several million light-sensitive cells of two types:

While peripheral vision allows only the detection of objects that are strongly contrasted and in movement, central vision ensures identification.

The eye contains about 125 million light-sensitive cells (120 million rods, 5 million cones). The information from these cells is sent to the brain via the optic nerve. This optic nerve consists of around one million nerve fibers. Its function is the coding of the information before sending it to the brain. The optic nerve is connected to the retina at a point where there are no light-sensitive cells. This area is called the blind spot. It is centered, according to certain individuals, between 10 and 16° to the left of the optical axis for the left eye and 10 and 16° to the right of the optical axis for the right eye with each covering a square section of about 3°. No detection is possible in these monocular visual areas. To compensate for the lack of detection in the blind spot of one eye, the brain uses information collected from the other eye.

To demonstrate the eye’s blind spot the reader should refer to the following illustration. Cover the left eye and focus on the cross with the right eye. Holding the diagram at arm’s length, move it forwards until the plane disappears.

2.1.1.2 Eye Movements

The eye moves in two different ways:

2.1.1.3 Empty-field Myopia

In the absence of a visual stimulus for the eye, as in the case of empty airspace for example, it focuses on its rest position which is located at between 1 and 2 meters, thus hindering the detection of potential distant targets. This phenomenon is called empty-field myopia.

2.1.1.4 Contrast and Visual Acuity

The contrast perceived between an object and the background on which it appears is linked to the difference between the brightness of the object (or the quantity of light emitted by the object’s surface) and the brightness of the background.

Visual acuity, which determines the quality of an image passed on to the brain by the eye can be likened to the separating power of an optical system. Visual acuity is 10/10 if the eye can separate two points seen within a one-minute angle arc, and 1/10 if the eye distinguishes this detail within 10 minutes. Visual acuity decreases as one moves away from the central field of vision. It is a function of increasing contrast. For example a white glider in a milky sky will be difficult to distinguish.

The blind spot, jerky eye movement, empty-field myopia and the decrease in peripheral vision performance constitute obstacles to the detection of targets or potential conflicts. Furthermore, although the visual acuity of pilots is regularly checked, the eye’s capacities diminish with age, environment and fatigue.

2.1.1.5 Psycho-visual Stages

Central mechanisms of perception and memorization are used in the recognition of the shape and the trajectory of an aircraft.

Processing time for visual information is half-a-second for the transmission of the visual message to the central structures and two and a half seconds for brain recognition. The result is a three-second delay between the moment that an aircraft becomes perceptible and the moment that a pilot can identify it as such.

2.1.2 Characteristics of Mid-air Collisions

2.1.2.1 Convergence at a Constant Bearing

The pilots of two aircraft flying at a constant speed and altitude and having convergent trajectories will each see the other aircraft at a constant bearing. In other words, the converging traffic will be motionless for the pilot. This visual immobility is dangerous because detection is very often made through peripheral vision and, as seen previously, peripheral vision is mainly stimulated by movement.

2.1.2.2 Dead Angles

Binocular vision passes on two images from the eyes to the brain. For an object placed at infinity both images are similar. For an object moved closer (around one meter) it is observed by both eyes at different angles. This phenomenon allows terrain to be differentiated.

A dead angle corresponds to an area of the environment masked by an object and therefore not seen. So for each eye, which adjusts to infinity, an object placed nearby can constitute a different dead angle. The overlapping of these two areas creates a masked zone that can, according to the situation, stretch to infinity. In a plane a windshield post can create a particularly troublesome dead angle.

The outside visibility limitations are shown below for the C177, due to the dead angle caused by the door and windshield posts.

It is, in addition, possible to observe a coincidence between the blind spot of one eye and the dead angle of the other.

2.1.2.3 Increasing Size of the Target During Approach

When two planes are approaching, their pilots will obviously see the other plane get bigger. However this increase in size does not follow a law of linear variation. The following drawing illustrates this phenomenon. It represents the view that a pilot flying a plane at 100 kt has of another approaching plane also flying at 100 kt and with about a ten-meter wingspan. In order to better illustrate the drawing, place it at arm’s length.

2.1.2.4 Response Time

Response time cannot be considered as a constant. It depends on the pilot and on the aircraft. It includes the recognition of the target (aircraft), the analysis of a potential collision, the decision to avoid it, action on the controls and the time required to maneuver the aircraft. Some seconds are necessary to go through this sequence. Moreover, the element of surprise can delay or block the pilot’s response time.

The previous illustration shows the size of an aircraft approaching at low speed five seconds before impact. Detection of this small target, integrated into the workload of the pilot, is not easy.

Apart from the limits inherent in the visual system, conflicting trajectories present very particular characteristics:

The see-and-avoid rule can therefore be faulted due to the physiological limits of human sight, accelerated speeds and the ergonomics of aircraft. In a report on a collision between a public transport plane and a glider (in February, 1999) the BEA reached the a conclusion on «the inadequacy of the see-and-avoid concept, considering current characteristics of aviation.»

Two other factors can contribute to lessen outside vigilance:

2.2 Knowledge of Regulations

The classification of airspace, identified by a letter, has been in effect in France since April 2, 1992. This classification, corresponding to the stipulations of Annex 2 to the Chicago Convention, allows controlled airspace to be distinguished from uncontrolled airspace, and to associate them with the air traffic services offered. Controlled airspaces are of class A, B, C, D, and E. The uncontrolled airspace is of class F and G. In France, only airspace of classes A, D, E, G exist.

The lack of sufficient knowledge of the rules applying to these classes of airspace often leads pilots to make errors.

In the case of pilots having limited experience or flying little, the nuances between spacing, traffic and flight information are not always assimilated.

2.3 Use of Radio Communications

The use of radio, compulsory in certain airspace, is optional in others. Analysis of accidents shows that pilots can thus stay out radio contact, often through fear or habit. By behaving thus, they deprive themselves of the flight information that could be supplied to them. Furthermore, they do not inform the control tower or other aircraft of their presence in the zone.

On the other hand, it sometimes appears that radio use brings a false sense of security. Pilots believe that they are benefiting from traffic information or spacing while, in reality, only flight information is supplied to them. In this case, danger can come from an aircraft unknown to the controller. The latter is applicable to pilots flying under IFR.

2.4 Use of Transponder

As previously mentioned, air traffic control has several methods to identify, separate, and inform pilots. Radio is an information vector that works both ways. Radar also allows controllers to know the position of aircraft better. The first primary radars required no onboard device but radars used today only detect an aircraft if it is equipped with a transponder. Gradually more and more aircraft are equipped with one, as are all commercial airliners and planes flying IFR. Other planes are also often equipped with a transponder, gliders and home-built planes less so. This device, if it is switched on, allows the plane to be tracked on radar screens but it may also allow pilots of planes equipped with the TCAS system to have first-hand knowledge of potentially dangerous traffic. This TCAS system is becoming widespread among commercial airliners.

In the BEA accident report about the mid-air collision on July 30th 1998 off the coast of Quiberon, it is noted that «a certain number of users do not apply section RAC 1-05 of the Aeronautics Information Manual relative to the requirement made upon the pilot of a plane equipped with a transponder to use code 7000 with altitude showing in the absence of air traffic control instruction.» This requirement was included in the documentation given to pilots in a way that could be interpreted as optional, which explains why it is still very little known. Moreover, the transponder is sometimes perceived as a surveillance device used by air traffic organizations to track down offences.

In the last two collisions involving a public transport plane it was found that if the tandem TCAS/transponder had been used, the risks of the collision would have been minimized.

2.5 Mid-air Collisions Near Aerodromes

There are rules, procedures or recommended practices appropriate for decreasing the risk of collision, notably in sectors where the traffic density is high.

This is the case around aerodromes. Some are controlled and radio contact is compulsory, others can be on air-to-air communication and radio use may be optional. For landing, a traffic pattern must be followed and, at aerodromes where radio is not compulsory, an integration maneuver should be performed.

In every case of a mid-air collision near an aerodrome, the radio was not used correctly or, the integration procedure or the runway circuit was not respected. On this last point, there are cases where the pilots ‘shortened’ runway circuits with a concern for efficiency to the detriment of safety.

The non-use of radio, excessive confidence in flight information and misinterpretation of regulations are factors encountered in the accidents studied.

This study shows that all pilots whatever their age, their qualifications or the flight rules applied can be confronted with the risk of mid-air collision. The number of these accidents is low, but they often have serious consequences.

The increasing number of aircraft, the complexity of certain routes, the improved performances and ergonomics of cockpits should incite pilots to use all means available in order to detect and to be detected by others.

Finally, regulatory developments are indispensable because the see-and-avoid rule is often the only guarantee of avoiding a collision. This basic rule, in a context where there are more and more constraints, is no longer adequate.

In addition to the recommendations made by the BEA with regard to the accidents in Quiberon and Montpellier, several measures can be suggested on the basis of the preceding findings in order to reduce the risk of mid-air collisions. First of all, considering the limitations of human sight which makes it difficult to spot an aircraft on a collision course, that is to say on a constant bearing, it is advisable to favor everything which can improve perception:

Pilots in VFR, or flying IFR in airspace where there can be VFR flights, should be made aware of the existence of the real risk of collision and of the importance of being vigilant at all times. Especially:

Finally it would be advisable to improve the operation of the see-and-avoid rule, without underestimating the limitations. This comes about with good and regular training of private pilots in:

Note: the production of films or simulation programs intended for schools and training centers could contribute to the application of these points.

What are the chances of a mid-air collision? Threat to your flight REVEALED

Shocking moment Air Canada plane nearly lands on FOUR planes

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There are many unsettling aspects of flying, from waiting in airport queues to flight delays and less-than-pleasant turbulence once you’re on board.

But one factor many passengers might not consider is the task of avoiding other planes while soaring sky-high.

There have been many instances in recent years of aircraft coming into extremely close proximity with each other.

The military plane followed the commercial aircraft along its left wing, before eventually peeling off.

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In 1978 a Pacific Southwest Airlines (PSA) flight collided with a Cessna light plane over San Diego, killing 144 people.

The dangers of mid-air collisions have prompted aviation regulators to enforce strict standardised rules for the industry.

According to Civil Aviation Authority (CAA) regulations, large commercial aircraft must fly at least three miles apart horizontally and 1,000 feet apart vertically.

The CAA said: «Within controlled airspace there are strict rules on how far airliners must be apart. Close to airports the separation is a minimum of three miles horizontally or 1,000ft vertically.

«Once an aircraft is in an airway the horizontal separation normally increases to five miles.»

Jet2 passengers were shocked to see this fighter jet outside their windows

The task of avoiding other planes is left in the hands of pilots, air traffic control and the electronic equipment installed on commercial planes.

British Airways pilot Steve Allright explained: ”There are three things you should know. Firstly Air Traffic Controllers around the world are carefully selected, highly trained and rigorously tested and licensed.

“Their job is to create a protective bubble around the aircraft which increases in size as the aircraft climbs and gets faster.

“Secondly, pilots are selected and trained to have a high level of situational awareness and are the most highly regulated professionals in any industry.

Pasenger planes have to fly three miles apart horizontally and 1,000ft vertically

“Thirdly, all commercial aircraft are fitted with electronic equipment which allows them to talk to each other, which removes the human element and provides warning and guidance of any proximity to another aircraft.

“We practice using this equipment in the simulator.»

While the risk of mid-air collisions is extremely rare, there are other sky-high threats for passenger planes.

Bird strikes and drones have both proven problematic for pilots, but aircraft are built to withstand extreme force in the air.

2002 Überlingen mid-air collision

The 2002 Überlingen mid-air collision occurred at 23:35 UTC on 1 July 2002 between Bashkirian Airlines Flight 2937 (a Tupolev Tu-154M passenger jet carrying 57 passengers Template:Ndashmostly children Template:Ndashand twelve crew) and DHL Flight 611 (a Boeing 757-23APF cargo jet manned by two pilots) over the towns of Überlingen and Owingen in southern Germany. All 71 people on board the two aircraft were killed. [1]

On 24 February 2004, Peter Nielsen, the air traffic controller on duty at the time of the accident, was stabbed to death by Vitaly Kaloyev. [2] Kaloyev, an architect, had lost his wife and two children in the accident. [3] [4]

Contents

Flights involved [ ]

Bashkirian Airlines Flight 2937 was a chartered flight from Moscow, Russia to Barcelona, Spain, carrying sixty passengers and nine crew. Forty-five of the passengers were Bashkortostan schoolchildren on a school trip organized by the local UNESCO committee to the Costa Daurada area of Spain. [5] [6] [7] [8] Most of the parents of the children were high-ranking officials in Bashkortostan. [9] The aircraft, a Tupolev Tu-154M registered as RA-85816, was piloted by a Russian crew. The captain Alexander Mihailovich Gross (Александр Михайлович Гросс) and first officer Oleg Pavlovich Grigoriev (Олег Павлович Григорьев) flew the Tupolev. Grigoriev, the chief pilot of Bashkirian Airlines, used the trip to evaluate Gross’s performance. Murat Ahatovich Itkulov (Мурат Ахатович Иткулов), normally the first officer, did not officially serve on duty because of this. The crew valued the opinions and guidance of Itkulov, who was slated to be promoted to captain. Sergei Kharlov, a navigator, and a flight engineer joined the three pilots. [10]

DHL Flight 611, a Boeing 757-23APF cargo aircraft registered as A9C-DHL, had originated in Bahrain and was being flown by two Bahrain-based [6] [11] pilots, British captain Paul Phillips and Canadian first officer Brant Campioni. [8] At the time of the accident, it was en route from Bergamo, Italy to Brussels, Belgium.

Accident [ ]

The two aircraft were flying at flight level 360 (approximately 36,000 feet (11,000 m) above Mean Sea Level) on a collision course. Despite being over Germany, the airspace was controlled from Zürich, Switzerland by the private Swiss airspace control company Skyguide. The only air traffic controller handling the airspace, Peter Nielsen, was working two workstations at the same time. He did not realise the problem in time and thus failed to keep the aircraft at a safe distance from each other. Only less than a minute before the accident did he realize the danger and contacted Flight 2937, instructing the pilot to descend by a thousand feet to avoid collision with crossing traffic (Flight 611). Seconds after the Russian crew initiated the descent, however, their traffic collision avoidance system (TCAS) instructed them to climb, while at about the same time the TCAS on Flight 611 instructed the pilots of that aircraft to descend. Had both aircraft followed those automated instructions, it is likely that the collision would not have occurred. [BFU 1]

Flight 611’s pilots on the Boeing jet initially followed the TCAS instructions and initiated a descent, but could not immediately inform the controller due to the fact that he was dealing with Flight 2937. About eight seconds before the collision, Flight 611’s descent rate was about 2,400 feet per minute (12 m/s), not as rapid as the 2,500 to 3,000 ft/min (13 to 15 m/s) range advised by TCAS. The Russian pilot on the Tupolev disregarded the TCAS instruction to climb and instead began to descend, as instructed by the controller, thus both planes were now descending. [BFU 1]

Unaware of the TCAS-issued alerts, Nielsen repeated his instruction to Flight 2937 to descend, giving the Tupolev crew incorrect information as to the position of the DHL plane. Maintenance work was being carried out on the main radar system, which meant that the controllers were forced to use a slower system. [BFU 1]

The aircraft collided at almost a right angle at an altitude of 34,890 feet (10,630 m), with the Boeing’s vertical stabilizer slicing completely through Flight 2937’s fuselage just ahead of the Tupolev’s wings. The Tupolev exploded and broke into several pieces, scattering wreckage over a wide area. The nose section of the aircraft fell vertically, while the tail section with the engines continued, stalled, and fell. As the nose section of the Tupolev fell at such speed, the flight deck crew soon lost consciousness. The crippled Boeing, now with 80% of its vertical stabilizer lost, struggled for a further seven kilometres (four miles) before crashing into a wooded area close to the village of Taisersdorf at a 70 degree downward angle. Each engine ended up several hundred metres away from the main wreckage, and the tail section was torn from the fuselage by trees just before impact. All 69 people on the Tupolev, and the two on board the Boeing, died. [BFU 1]

Other factors in the crash [ ]

Only one air traffic controller, Peter Nielsen of ACC Zurich, was controlling the airspace through which the aircraft were transitioning. The other controller on duty was resting in another room for the night. This was against the regulations, but had been a common practice for years and was known and tolerated by management. Due to maintenance work, Nielsen had a stand-by controller and system manager on call. Nielsen was either unaware of this or he chose not to use either of the two additional air traffic controllers available to him. [BFU 2] When Nielsen realised that the situation had subtly increased beyond his span of control, it was too late to summon assistance.

In the minutes before the accident, Nielsen was occupied with an Airbus on a delayed Aero Lloyd Flight 1135 approaching Friedrichshafen Airport. [BFU 3] Handling two workstations at once, Nielsen struggled with the malfunctioning phone system that he was trying to use to call the Friedrichshafen airport to announce the approaching Aero Lloyd. The main phone lines at Skyguide were down due to maintenance work, and the backup line was defective. This caused Nielsen to spend more time than he anticipated coordinating the Airbus late arrival into Friedrichshafen, and to miss several calls from aircraft. The faulty phone lines also prevented adjacent air traffic controllers at Karlsruhe from phoning in a warning. Due to these distractions he did not spot the danger until about a minute before impact. Had he been aware of the dangerous situation earlier, he could have kept the aircraft at a safe distance from each other. They would have been separated and their collision avoidance systems would not have issued instructions.

Additionally, after Nielsen instructed the Russian crew to descend, he returned to the situation with the Airbus bound for Friedrichshafen, and did not hear the DHL aircraft TCAS report of its descent.

Another factor was that the ground-based optical collision warning system, which would have alerted the controller to imminent collisions early, had been switched off for maintenance; Nielsen was unaware of this. There still was an aural STCA warning system, which released a warning addressed to workstation RE SUED at 21:35:00 (32 seconds before the collision); this warning was not heard by anyone present at that time, although no error in this system could be found in a subsequent technical audit; whether this audible warning is turned on or not, is not logged technically. Even if Nielsen had heard this warning, he might have misinterpreted it until the next radar update 12 seconds later became visible or until the TCAS descent notice by the DHL crew came in; at that time finding a useful resolution order by the air traffic controller is difficult to impossible. [BFU 4]

Deviating statements in the official report [ ]

All countries involved could add additional «deviating» statements to the official report. The Kingdom of Bahrain, Switzerland and the Russian Federation did submit positions that were published with the official report. The USA did not submit deviating positions. The comments were published as an appendix to the report but were not commented upon by the German federal investigators. [12]

The statement by the Kingdom of Bahrain, the home country of the DHL plane, mostly agrees with the findings of the report. It says that the report should have put less emphasis on the actions of individuals and stressed the problems with the organisation and management more. Bahrain’s statement also mentions the lack of crew resource management in the Tupolev’s cockpit as a factor in the crash. [12]

The Russian Federation states that the Russian pilots were unable to obey the TCAS advisory to climb; the advisory was given when they were already at 35500 feet while the controller wrongly stated there was conflicting traffic above them at 36000 feet. Also, the controller gave the wrong position of the DHL plane (2 o’clock instead of the actual 10 o’clock). Russia asserts that the DHL crew had a «real possibility» to avoid a collision since they were able to hear the conversation between the Russian crew and the controller. [12]

Switzerland notes that the Tupolev was about 33 metres below the flight level ordered by the Swiss controller, and still descending at 1900 feet per minute. The Swiss say that this was also a cause of the accident. The Swiss position also states that in spite of the false information given (position and phraseology) by the Swiss controller the TCAS advisories would have been useful if obeyed immediately. [12]

The change in magnetic bearing of the Russian aircraft by cumulatively 20 degrees (from 254 to 274) during the upcoming conflict is not assessed in the official report.

Consequences [ ]

Skyguide memorial to the aviation accident and murder of Peter Nielsen.

Nielsen needed medical attention due to traumatic stress caused by the accident. [13] At Skyguide, his former colleagues maintained a vase with a white rose over Nielsen’s former workstation. [14] Skyguide, after initially having blamed the Russian pilot for the accident, accepted its share of the responsibility and asked relatives of the victims for forgiveness. [15] On 19 May 2004, the official investigators found that managerial incompetence and systems failures were the main cause for the accident, so that Nielsen was surely not the only one to be blamed for the disaster. As explained above, a series of coincidences of which Kaloyev and Nielsen were unaware precipitated the accident. Template:Citation needed

On 27 July 2006, a court in Konstanz decided that the Federal Republic of Germany should pay compensation to Bashkirian Airlines. The court found that it was illegal for the state to allow a foreign private company to provide air traffic control in German airspace. The government appealed the ruling, and a final decision is still pending as of 2008. [16]

In another case before the court in Konstanz, Skyguide’s liability insurance is suing Bashkirian Airlines for 2.5 million euro in damages. The case was opened in March 2008; the legal questions are expected to be difficult, as the airline has filed for bankruptcy under Russian law. [16]

TCAS and conflicting orders [ ]

The accident raised questions on how pilots must react when they receive conflicting orders from the TCAS and from air traffic control (ATC). The TCAS is programmed to assume that both crews will promptly follow the system’s instructions. The operations manual clearly states that TCAS should always take precedence over any ATC commands: If an instruction to manoeuvre is received simultaneously from an RA (resolution advisory, the command issued by the TCAS) and from ATC, the advice given by RA should be followed. [BFU 1]

It is not required to notify the ATC prior to responding to an RA. This manoeuvre does not require any ATC clearance since TCAS takes into account the position of all other aircraft with transponders in the surrounding area. Template:Citation needed

Prior incidents [ ]

About a year before the Bashkirian-DHL collision there had already been another incident involving confusion conflicting TCAS and ATC commands. During the 2001 Japan Airlines mid-air incident, two Japanese airliners nearly collided with each other in Japanese skies. Both aircraft had received conflicting orders from the TCAS and ATC; one pilot followed the instructions of the TCAS while the other did not. Disaster was only averted because one of the pilots made evasive manoeuvres based on a visual judgement. The aircraft missed each other by less than 100 metres (330 ft), and the abrupt manoeuvre necessary to avert disaster left about 100 occupants hurt on one aircraft, some seriously. As a consequence Japan called for measures to prevent similar incidents. However, the International Civil Aviation Organization (ICAO) did not take action until after the crash over Germany. [19] In addition four near misses in Europe occurred before the German disaster, because one set of pilots obeyed the air traffic controllers while the other obeyed TCAS. The ICAO decided to fulfill Japan’s request 18 months after the Japan Airlines incident. [10]

Unclear instructions for the Bashkirian crew [ ]

The Bashkirian pilots were using the Tu-154 Flight Operations Manual, which contained a section that emphasizes the role of the ATC and describes the TCAS as an additional aid: [BFU 5] Template:Cquote

The same flight manual, on a different page, also contains a passage that strictly forbids manoeuvers contrary to the TCAS under any circumstances. Nevertheless, the official investigation found that the pilots seemed unaware that the TCAS RA should take precedence. [BFU 6]

Technical solutions [ ]

Recommendations after the accident [ ]

The investigation report contains a number of recommendations concerning TCAS, calling for upgrades and for better training and clearer instructions to the pilots. [BFU 1]

Notable passengers on Flight 2937 [ ]

Fourteen-year old Kirill Degtyarev created paintings from age 4 to his death and had held two public exhibitions. After his death, Ufa hosted one exhibition and Überlingen hosted another exhibition. [10] The family of future deputy North Ossetian housing minister Vitaly Kaloyev all died. Kaloyev would later go on to murder Nielsen.

Murder of Peter Nielsen [ ]

Grieved by the loss of his family, Vitaly Kaloyev held Peter Nielsen responsible for their deaths. He stabbed Nielsen to death at his Kloten home, near Zürich, on 24 February 2004. [14] [21] Police arrested Kaloyev at a local motel not long after the murder, and he was subsequently convicted of the crime in 2005. He was released on 8 November 2007 because his mental condition was not sufficiently considered in the initial sentence. After his release, Kaloyev was infamously dubbed a «hero» in North Ossetia. In January 2008, he was appointed deputy construction minister of North Ossetia. [22]

Dramatization [ ]

The Discovery Channel Canada documentary series Mayday featured this accident in the episode titled Deadly Crossroads, which was released in 2004. [23]

The National Geographic Channel documentary series Seconds From Disaster featured this mid-air collision in the episode entitled Collision at 35,000 feet release in 26th September 2011.

Related Articles [ ]

External links [ ]

On conflicting orders [ ]

Template:Aviation incidents and accidents in 2002 Template:Lists of aviation accidents and incidents

Cite error: tags exist for a group named «BFU», but no corresponding tag was found