1、CIRCULAR 213-AN/130 I G, CIRCULAR PILOT SKILLS TO MAKE “LOOK-OUT” MORE EFFECTIVE IN VISUAL COLLISION AVOIDANCE Approved by the Secretary General and published under his authority INTERNATIONAL CIVIL AVIATION ORGANIZATION MONTREAL o CANADA COPYRIGHT International Civil Aviation OrganizationLicensed b
2、y Information Handling ServicesICA0 CIRCULAR*213 t* = 4843436 0004569 366 Do you receive the ICA0 BULLETIN? The ICA0 Bulletin contains a concise account of the activities of the Organization as well as articles of interest to the aeronautical world. The Bulletin will also keep you up to date on the
3、latest ICAO publications, their contents, amendments, supplements, corrigenda and prices. Available in three separate editions: English, French and Spanish. Annual subscription: U.S.$20.00 (surface mail); U.S.$25.00 (air mail). - - - _ - - - -_I _ _- I - J _ - , Published in separate English, French
4、, Russian and Spanish editions by the International Civil Aviation Organization. All correspondence, except orders and subscriptions, should be addressed to the Secretary General. Orders for this publication should be sent to one of the following addresses, together with the appropriate remittance (
5、by bank draft or post office money order) in U.S. dollars or the currer-cy of the country in which the order is placed. Document Sales Unit International Civil Aviation Organization loo0 Sherbrooke Street West, Suite 400 Montreal, Quebec Canada H3A 2R2 Egypt. ICAO Representative, Middle East Office,
6、 16 Hassan Sabri, Frunce. Reprsentant de lOACI, Bureau Europe, 3 bis, villa mile-Bergerat, India. Oxford Book and Stationery Co., Scindia House, New Delhi Japon. Japan Civil Aviation Promotion Foundation, 15-12, 1-chome, Toranomon, Zamalek, Cairo. 92522 Neuilly-sur-Seine (Cedex). or 17 Park Street,
7、Calcutta. Minato-Ku, Tokyo. Kenya. ICAO Representative,-Eastern and Southern African Office, United Nations Mexico. Representante de la OACI, Oficina Norteamrica. Centroamrica y Caribe, Accommodation, P.O. Box 46294 Nairobi. Apartado postal 5-377, C.P. 11590, Mxico 5, D.F. Peru. Representante de la
8、OACI, Oficina Sudamrica, Apartado 4127, Lima 100. Senegal. Reprsentant de IOACI, Bureau Afrique occidentale et centrale, Spain. Pilots, Suministros Aeronuticos, S.A., C/Ulises, 5-Oficina Nm. 2, 28043 Madrid. Thailand. ICAO Representative, Asia and Pacific Office, P.O. Box 614, Bangkok. Bote postale
9、2356, Dakar. United Kingdom. Civil Aviation Authority, Printing and Publications Services, Greville House, 37 Gratton Road, Cheltenham, Gios., GL5O 2BN. COPYRIGHT International Civil Aviation OrganizationLicensed by Information Handling Services1. 2. 3. 4. 5. 6. 7. 8. ICA0 CIRCULARfZL3 ft m 484i14Lb
10、 0004570 O88 m TABLE OF CONTENTS Introduction Causes of mid-air collisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limitations of he eye . . . . . . . . . . . . . . . . . . . .-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Visual scannin
11、gtechnique . How to scan = Scan patterns The .time-sharing plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Collision avoidance checklist. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page COPYRIGHT
12、International Civil Aviation OrganizationLicensed by Information Handling ServicesICA0 CIRCULAR*233 tt m 4843436 0004573 T34 1. INTRODUCTION 1.1 The practice of “see-and-avoid” is recognized as the primary method that a pilot uses to minimize the risk of collision when flying as an uncontrolled flig
13、ht in visual meteorological conditions. “See-and-avoid” is directly linked with a pilots skill at looking about outside the cockpit or flight deck and becoming aware of the surrounding visual environment. Its effectiveness can be greatly improved if the pilot can acquire skills to compensate for the
14、 limitations of the human eye. These skills include the application of effective visual scanning, the ability to listen selectively to radio transmissions from ground stations and other aircraft to create a mental picture of the traffic situation, and the development of habit patterns that can be de
15、scribed as “good airmanship”. 1.2 This circular aims to make pilots aware of the skills required to make “look-out” more effective and is directed mainly towards those pilots who do most of their flying under.visual flight rules (VFR). The skills should be of interest to all pilots, however, regardl
16、ess of the type of aircraft they fly and the flight rules under which they fly since no pilot is immune to collisions. 1.3 A study of over two hundred reports of mid-air collisions showed that they can occur in all phases of flight and at all altitudes. It may be surprising that nearly all mid-air c
17、ollisions occur during daylight hours and in excellent visual meteorological conditions. While the majority of mid-air collisions occurred at lower altitudes where most VFR flying is carried out, collisions can and did occur at higher altitudes. Because of the concentration of aircraft in the vicini
18、ty of aerodromes, most collisions occurred near aerodromes when one or both aircraft were descending or climbing. Although some aircraft were operating as instrument flight rules (IFR) flights, most were VFR and uncontrolled. 1.4 The pilots involved in the collisions ranged in experience from first
19、solo to 15 O00 hours of flight time, and their reasons for flying that day were equally varied. In one case a private pilot flying cross-country, legally VFR, in a single-engine aircraft collided with a turboprop aircraft under IFR control flown by two long-time experienced airline pilots. In anothe
20、r case, a 7 000-hour commercial pilot on private business in a twin-engine aircraft overtook a single- engine aircraft on its final approach piloted by a young flight instructor giving dual instruction to a non-soloed student pilot. Two commercial pilots, each with well over 1 O00 hours, collided wh
21、ile ferrying a pair of new single-engine aircraft; and two private pilots with about 200 hours logged between them collided while on local pleasure flights in small single-engine aircraft. 1.5 There is no way to say whether it is the experienced or the inexperienced pilot who is more likely to be in
22、volved in a mid-air collision. While a novice pilot has much to think about and so may forget to maintain an adequate look-out, the experienced pilot, having flown through many hours of routine flight without spotting any hazardous traffic, may grow complacent and forget to scan. 1.6 If you learn to
23、 use your eyes and maintain vigilance through proper awareness, it will not be difficult for you to avoid mid-air collisions. The results of studies of the mid-air collision problem show that there are certain definite warning patterns. 1 -. - i COPYRIGHT International Civil Aviation OrganizationLic
24、ensed by Information Handling ServicesICA0 CIRCULAR*iX3 * 4B414Lb O004572 950 2 ICA0 Circular 213-A NI130 2. CAUSES OF MIDAIR COLLISIONS 2.1 What contributes to mid-air collisions? Undoubtedly, traffic congestion and aircraft speeds are part of the problem. In the head-on situation, for instance. a
25、jet and a light twin- engine aircra!t may have a closing speed of about 1 200 kmih (650 kt). It takes a minimum of 10 seconds for a pilot to spot traffic. identify it, realize it is a collision threat, react, and have the aircraft respond. But two aircraft converging at 1 200 kmlh (650 kt) will be l
26、ess than 10 seconds apart when the pilots are first able to see each other! 2.2 are, in some cases, overloaded and limited. These problems are compounded by the fact that air traffic control and radar facilities 2.3 These factors are all contributory causes, but the reason most often noted in the mi
27、d-air collision statistics reads “failure of pilot to see other aircraft” - in other words, failure of the see-and-avoid system. In most cases at least one of the pilots involved could have seen the other in time to avoid the collision if that pilot had been watching properly. Therefore, it could be
28、 said that it is really the eye which is the leading contributor to mid-air collisions. Take a look at how its limitations affect your flight. 3. LIMITATIONS OF THE EYE 3.1 The human eye is a very complex system. Its function is to receive images and transmit them to the brain for recognition and st
29、orage. It has been estimated that 80 per cent of our total information intake is through the eyes. In other words the eye is our prime means of identifying what is going on around us. 3.2 In the air we depend on our eyes to provide most of the basic input necessary for flying the aircraft, e.g. atti
30、tude, speed. direction and proximity to opposing air traffic. As air traffic density and aircraft closing speeds increase, the problem of mid-air collision increases considerably, and so does the importance of effective scanning: A basic understanding of the eyes limitations in target detection is p
31、robably the best insurance a pilot can have against col1 is ion. 3.3 The eye, and consequently vision, is vulnerable to many things including dust, fatigue, emotion, germs, fallen eyelashes, age, optical illusions, and the effect of alcohol and certain medications. In flight, vision is influenced by
32、 atmospheric conditions, glare, lighting, windshield distortion, aircraft design, cabin temperature, oxygen supply, acceleration forces and so forth. 3.4 Most importantly, the eye is vulnerable to the vagaries of the mind. We can “see” and identify only what the mind permits us to see. A daydreaming
33、 pilot staring out into space is probably the prime candidate for a mid-air collision. 3.5 One inherent problem with the eye is the time required for accommodation or refocusing. Our eyes automatically accommodate for near and far objects, but the change from something up close! like a dark instrume
34、nt panel two feet away, to a well lighted landmark or aircraft target a mile or so away, takes one to two seconds. That can be a long time when you consider that you need 10 seconds to avoid a mid-air collision. (See Figures 1 and 2.) COPYRIGHT International Civil Aviation OrganizationLicensed by In
35、formation Handling ServicesICAO CIRCULARtZL3 tt m 4841436 0004573 897 H ICAO Circular 213-ANI130 3 Focus point 1 m (compass) Focus point 500 m (aircraft) Figure I. Recognition of an aircraft depending on the eye accommodation Aircraft head-on, focus point straight ahead Aircraft on crossing track, f
36、ocus point 45O (right) Figure 2. Apparent size of light aircraft at 500 m distance 3.6 Another focusing problem usually occurs when there is nothing to specifically focus on, which usually happens at very high altitudes, as well as at lower levels on vague, colourless days above a haze or cloud laye
37、r when no distinct horizon is visible. Pilots experience something known as “empty-field myopia”, .e. staring but seeing nothing, not even opposing traffic entering their visuai field. 3.7 The effects of what is called “binocutar vision have been studied during investigations of mid-air collisions,
38、with the conclusion that this is also a causal factor. To actually accept what we see, we need to receive cues from both eyes. If an object is visible to only one eye, but hidden from the other by a windshield post or other obstruction, the total image is blurred and not always acceptable to the min
39、d. Therefore, it is essential that pilots move their head when scanning around obstructions. (See Figure 3.) COPYRIGHT International Civil Aviation OrganizationLicensed by Information Handling Services ICAO CIRCULAR*213 * 4841iYLh 0004574 723 4 ICAO Circular 213-ANI130 3.8 Another inherent eye probl
40、em is the narrow fleld of vision. Although our eyes accept light rays from an arc of nearly 2ooo, they are limited to a relatively narrow area (approximately 10-15O) In which they can actually focus on and classify an object. Although movement on the periphery can be perceived, we cannot identify wh
41、at is happening there, and we tend not to believe what we see out of he corner of our eyes. This, aided by the brain, often leads to “tunnel vision”. 3.9 Motion or contrast is needed to attract the eyes attentlon, and tunnel vision limitation can be compounded by the fact that at a distance an aircr
42、aft on a collision course will appear to be motionless. The aircraft wlll remain in a seemingly stationary position, without appearing to move or to grow in size, for a relatively long time, and then suddenly bloom into a huge mass, almost filling up one of the windows. This is known as the “blossom
43、 effect“. It is frightening that a large insect smear or dirty spot on the windshleld can hide a converging aircraft until it is too close to be avoided. 3-10 In addition to its inherent problems, the eye is also severely limited by environment. Optical properties of the atmosphere alter the appeara
44、nce of aircraft, particularly on hazy days. “Limited visibillty” actually means “limited vision”. You may be legally VFR when you have 5 km (3 NM) visibility, but at that distance on a hazy day you may have difficulty in detecting opposing traffic; at that range, even though another aircraft may be
45、visible, a collision may be unavoidable because of the high closing speeds involved. 3.11 Light also affects our visual efficiency. Glare, usually worse on a sunny day over a cloud layer or during flight directly into the sun, makes objects hard to see and scanning uncomfortable. An aircraft that ha
46、s a high degree of contrast against the background will be easy to see, while one with low contrast at the same distance may be impossible to see. In addition, when the sun is behind you, an opposing aircraft will stand out clearly, but if you are looking into the sun, the glare of the sun will usua
47、lly prevent you from seeing the other aircraft. Another problem with contrast occurs when trying to sight an aircraft against a cluttered background. If the aircraft is between you and terrain that is varicoloured or heavily dotted with buildings, it will blend Into the background untll the aircraft
48、 is quite close. 3.12 And, of course, there is the mind, which can distract the pilot to the point of not seeing anything at all, or cause cockpit myopia - staring at one instrument without even “seeing” it. 3.13 As can be seen, visual perception is affected by many factors. Pilots, like others, ten
49、d to overestimate their visual abilities and to misunderstand their eyes limitatlons. Since a major cause of mid-air collisions is the failure to adhere to the practice of see-and-avoid, it can be concluded that the best way to avoid collisions is to learn how to use your eyes for an efficient scan. 4. VISUAL SCANNING TECHNIQUE 4.1 To avoid collisions you must scan effectively from the moment the aircraft moves until it comes to a stop at the end of the flight. Collision threats are present on the surface, at low altitudes in the vicinity of aerodrome
