t{ . , ....... 1,<."<4-~ A. N . \~ '- '( COMMONWEALTH OF AUSTRALIA I DEPARTMENT OF CIVIL AVl1\TION AVI A TION SAFETY DIGESlr No. 7 SEPTEMBER, 1956 Prepared by the Division of Published by Authority Printed by McBean Bros., 48 Rankins Road, Kensington. Accident Investigation and Analysis of the Director-General CONTENTS Page PART I-AVIATION NEWS AND VIEWS Misreading the Altimeter . 3 PART II-OVERSEAS ACCIDENTS DC-4 Fire in Flight . 5 DC-4 Ditching between Honolulu and Wake Island 6 Approach Accident, DC-6B, San Francisco Bay, California . 8 PART Ill-AUSTRALIAN ACCIDENTS Accident to DC-3 at Bourke, N.S.W. 10 I Accident to DC-3 on Instrument Approach to Cam- bridge (Hobart) Aerodrome 15 Take-off Accident near Stannum, N.S.W. 22 Helicopter Accident near Morehead, New Guinea 23 Collision with High Tension Wires . 23 DH-82 Mid-Air Collision near Werribee, Victoria 24 Fatal Stall in DH-82 . 25 Nose Heavy Norseman, New Guinea . 26 Proctor Lost in Cloud 26 DH -82 Take-off Accident . 27 Mid-Air Collision at Narromine, N.S.W. 2 7 PART IV-INCIDENT REPORTS Near Miss during l.F.R. Descent, Rome 29 The Need for Vigi lance in the Control Zone 29 V.F.R. and "Visual" Approaches . 30 Where you can assist AT.C. 31 • PART I AVIATION NEWS AND VIEWS Quiz Session pilots and non-pilot college students in r ead­ ing the 3-pointer altimeter. These persons Take a pencil, note the time, turn to page were allowed approximately 7 seconds for 32 and underneath each dial write the alti­ each reading. The types of errors, and the meter reading and then note the time you frequency of occurrence expressed as a per~ have taken to complete all readings. Check centage of the total readings, uncovered in your readings against those given on page 4. this analysis were- Now, perhaps, you will be interested to read the article which follows. (a) Reading to nearest numeral instead of lower adjacent numeral (reading 13,960 as 14,960 because of failure to consider the more sensitive pointer) Misreading the Altimeter -pilots 4.4 per cent, non-pilots 3.7 per cent. N accident report in this Digest con­ (b) Reading to the lower adjacent num­ cludes that a very experienced pilot eral when the nearest numeral is A probably misread the altimeter during correct (reading 28,020 as 27,020 an instrument approach. Although most because of failure to consider the more pilots are aware that the conventional sensi­ sensitive pointer)-pilots 0.3 per tive altimeter with three pointers has certain cent, non-pilots 2.3 per cent. inherent readability limitations, the high probability of misreading it is not generally (c) Displacement of digit in number appreciated. But only careless pilots would series (reading 16,080 as 10,680 be­ misread their altimeter, you think. Tests cause of interchange of digit with indicate that careful pilots also misread this adjacent zero )- pilots 4.0 per cent., instrument. non-pilots 5.5 per cent. In 1947, the United States Air Forces Aero (d) Misreading of scale or numeral (read­ Medical Laboratory analysed 270 errors ing 34,640 as 34,620) because of made by pilots in reading and interpreting erroneous value assigned to scale instruments. This analysis revealed, inter divisions)- pilots 5.8 per cent., non­ alia, that one of the most common errors was pilots 7.1 per cent. in int erpr eting multiple revolution instru­ (e) Omission of one pointer (reading ments such as the sensitive altimeter. The 10,700 as 700 because of failure to altimeter was misread more frequently than read 10,000 ft. pointer)-pilots 1.7 any other instrument and by far the most per cent., non-pilots 1.3 per cent. common error was that of reading the altitude exactly 1,000 feet too high. This (f) Pointer exchange (reading '25,420 as analysis also found that instrument reading 52,420 because of interchange of errors are not confined to any single class or 10,000 ft. and 1,000 ft. pointers)­ group of pilots. In these tests 97 pilots made pilots 0.3 per cent., non-pilots 2.3 per 12 readings each from conventional sensitive cent. altimeters and of the total of 1,164 readings 11.7 per cent. were in error by 1,000 feet or (g) Repetition of reading on one pointer (reading 28,020 as 28,820 because of more. repetition of 1,000 ft. pointer reading) In the following year the U.S.A.F. Aero - pilots 1.0 per cent., non-pilots 0.8 Medical Laboratory examined a number of per cent. 3 These errors are attributed to the fact that are read in digits through a window in the an exact numerical value is obtained from dial. An improved presentation of the baro­ data presented by a combination of pointers metric scale is also incorporated which PART II on a single dial. That is, the 3-pointer alti­ f eatu res a four digit type counter. Another meter by virtue of its method of presenta­ type of altimeter which is designed to tion affords opportunities for errors. The overcome the most sel'ious error in read­ most serious (hazardous) of these errors is ing the 3-pointer altimeter, i.e., reading OVERSEAS ACCIDENTS that referred to at (a), i.e. reading too high the 1,000 pointer to the nearest numeral, by one revolution of the sensitive pointer. is one in which the 1,000 pointer i·emains This error is demonstrated at F ig. 2, page pointing at the numeral indicating the 32, where the 1,000 ft. pointer is pointing to thousands of feet until the altitude changes 4 on the scale, but to read the setting correctly 1,000 feet when it jumps to the next appro­ DC.4 Fire in Flight it must be read as 3 or 3,000 feet. The priate numeral. An altimeter with one error comes from reading the 1,000 ft. pointer and a logarithmic scale, which it is pointer to the nearest numeral, whereas it claimed will considerably reduce the in­ (This su11irnary is based on the report of should be read to the next lowest number. cidence of reading errors, is currently being the Civil Aeronautics Board, U.S.A.) (18/ 27/ 43) evaluated in Canada and present indications The majority of cases of misreading of the are that it would be comparatively cheap to N 15th June, 1954, at 0320 hours a fire was seen to momentarily die down but altimeter have occurred during instrument produce. DC.4 made an emergency landing off the almost immediately to flare up again. descents when the pilot has been concentrat­ Orunway at Gag-e Airport, Okla­ ing on flight attitude instruments, radio The Department is currently examining homa. The emergency landing was made At approximately 0312 while the captain conversation and instrument procedures with the available improved types of altimeters because of an uncontrollable fire in the was performing these duties the first officer the result that the altimeter only gets a with a view to their suitability as replace­ number 3 engine nacelle. There were no called Gage and advised that the number glance. From studies of pilots' eye move­ ment for the 3-pointei· altimeter. REMEM­ injuries to the passengers or crew, but the 3 engine was on fire and that its propeller ments during instrument flying it is known BER, until the present type of 3iltimeter is aircraft was destroyed by fire. had been feathered. The Gage communicator that pilots spend an average of 4/lOths of replaced, the greatest danger is in reading immediately turned on the airport runway a second each time they read the altimeter this altimeter too high by 1,000 feet when lights for the north-south runway. There under these conditions. This is very short letting down in instrument conditions. THE FLIGHT were no other radio contacts with the flight. by comparison with the average time taken The aircraft was engaged on a flight from The captain, unable to extinguish the fire, in the above tests, 7 seconds per reading. Kansas City, Missouri to Burbank, Cali­ began a left descending turn toward the QUIZ ANSWERS: fornia. The flight was routine until, when airport. During this tum the number 3 As a result of the studies of errors in read­ in the vicinity of Gage, Oklahoma, the cap­ engine fell from the aircraft, at which time ing altitude, various aviation authorities 1 16,080 tain was requested to climb and maintain a complete failure of the electrical system and instrument manufacturers throughout 2 13,960 6,000 feet. Shortly after, the stewardess was experienced. The captain testified that the world have been engaged for some time 3 13,330 entered the cockpit and told the pilots that thrnughout the approach he was unable to in developing altimeters with improved pre­ 4 10,700 she had observed sparks trailing from see the runway lights on the airport, and, sentation. Quite a number of different types 5 84,640 number 3 engine. A check by the first officer not being able to use the aircraft landing of altimeters have now been developed and 6 25,420 failed to find anything amiss, and the lights, he headed in the general direction 6f are available for installation. 7 28,020 stewardess returned to the cabin. the airport beacon. Throughout the latter 8 1,100 stages of descent the first officer used a flash One type that appears to overcome most 9 11,000 Some two or three minutes later, when light so that he could observe and call out of the problems is the counter type.