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Aviation History
1948
1948 - 1733.PDF
OCTOBER 14TH, 1948 FLIGHT 471 CORRESPONDENCE The Editor does not hold himself responsible for the views expressed by correspondents. The names and addresses of the writers. not necessarily for publication, must in all cases accompany letters. BROUGH Why is the t.T.S. Closed ?H AVING read about new Reserve recruiting drives, morebranches and centres of the V.R. open for volunteers, and of women being admitted to the V.R., I was astonished whenvisiting East Yorkshire recently to find the Brough E.F.T.S. closed down. The air which for more than ten years has re-sounded to the "roar" of B2S and Tigers was almost silent. The reason for this closing down, now of all times, I cannotimagine. Brough has good permanent buildings and hangarage, and a great deal has been spent on extensions andimprovements to the airfield since early war days. The area is quite good for flying, although admittedly there is a fairamount of morning mist at certain times of the year. Up the river there is a very convenient relief and forced landing field. It may be that the flying training school was closed downat the request of the Blackburn company who own it, but this I find hard to believe. The testing of Prentices now made atBrough, and of one or two Firecrests, could hardly constitute a hazard to flying instruction on the airfield, or vice-versa. No. 4 E.F.T.S., of which I have very happy memories, isone of the oldest and soundest of the original E. and R.F.T.Ss. I understand from one of two of the local V.R.-ists to whom Italked, that there are plenty of volunteer pilots in the locality to support a Reserve centre, and more in the "pipeline"(whatever that may be) even before the latest intensified drive. There will be very many pilots, in and ex-uniform, whoremember their "sprog" days at Brough, and will join me in hoping that No. 4 will soon be reopened and making its con-tribution to the band of young pilots which we again need so badly. SMITH, NO. 4, - Radlett, Herts. ' ; : AIR ACCIDENT INVESTIGATION Altimeter Settings, Control Services and CommunicationsT HE letter from the Deputy Master of the Guild of Air Pilotsand Air Navigators in your issue of September 16th, criticizing the report on the accident to a Viking aircraft atNortholt on January 6th, will earn him the gratitude of all " B " licence pilots. There are few people who have the abilityto view these things without bias, and to present their con- clusions with precision and clarity. As a personal friend ofthe captain involved in this accident, the imputations of the report rankled with me, and-I could not be sure that I hadnot read into the report either more or less than was actually there. Thanks to Mr. Cumming's letter I see now that Imissed the significance of certain points. I would like to add a few general remarks on the subject ofwhy captains make these so-called " Errors of Judgment." An error of judgment only appears as such when the informationon which an action is taken is identical with the information which afterwards appears to have been available. If one ormore items of information assumed to be available to the pilot (or the control officer) were in actual fact not available, thenthe case to be judged is different, and the judgment may have been perfectly logical. Let us take the altimeter setting as a case in point. Thepilot assumed that (a) he had been passed the latest QFE, and (b) that he had set it correctly. Assumption (a) was wrong, buthe had no means of knowing it. Assumption (b) may or may not have been wrong; there is no proof that he set it onemillibar high. Assuming that he did set it wrongly, the alti- meter then read approximately 30 feet of excess height. Thissetting of altimeters accurately is a thing which is practically impossible to do under adverse conditions, because when youare strapped back in your seat your altimeter setting knob may be only just within reach at full stretch of your arm. Inaddition, the position of it on the panel may involve a parallax error of one millibar or more. Then again, turbulence and thedistance of it from your eye may make accurate setting of the fine divisions of the sub-scale impossible, especially in a poorlylit cockpit. Next we read that the zero setting of the altimeter was" within limits." This means it may have been a further sixty feet out, so that the altimeter may have been showing aheight which was up to 90 feet in excess of the true height above airport level. This means that cloud height, reportedto the captain as 400 feet, found by him to be 150 feet, may B 27 have been as low as 60 feet at the time he thought it was150 feet. His mental reaction would be that "they" don't seem to have much of a clue as to the vital factor of cloudbaseheight. In addition, the altimeter is reported as having a leak 60 per cent outside the limits, which presumably nobody knewanything about. These errors alone could make the difference between hitting and missing a tree-top, and would appear tomost people to be sufficient to admit that the pilot could be free from blame. Let me now proceed to some generalizations on factors affect-ing the correctness of any particular judgment of a situation. What about the pilot's confidence in the controller? It is afact that some control officers appear to pilots to be "clots," just as no doubt some pilots appear to control officers to be"clots." There is justification for these viewpoints being held. Admittedly there is more panicking in foreign controloffices than there is in the United Kingdom. A pilot feeling lack of confidence in the control service will, in an emergency,make a different decision from that he will make if he is con- fident in the control. This has often been done, but it is onlycalled an "Error of Judgment" in the event of an accident happening. The Control Service itself, unfortunately, has often encour-aged this "no confidence" state of mind by its inefficiency. This has been shown more lately in the case of Northolt by thecollision between a York and a D.C.6, in which it became known that the control officers apparently thought that 500feet separation between aircraft was safe. I was appalled when I read that, and thanked the Lord that the same had not hap-pened to me. Any particular aircraft had only to be 250 feet out of its height to be in danger of collision with the next oneabove or below, and it is very easy to be that much out by reason of (a) incorrect altimeter setting; (b) faulty altimeternot yet found out; (c) temporary inattention while fiddling with knobs and switches in an effort to obtain better receptionof either Control R/T or navigational or landing aid; (d) tur- bulence in cloud; or (e) a combination of any or all of these.No sir! If they reckon 500 feet is enough, I quit flying in I.F.R. I think probably the most frequent failure of the ControlService is in the extremely vital matter of communication. H.F. R/T is very often useless, owing to its short range andatmospheric background noises. V.H.F. is good provided it is working well, but often in aircraft sets reception is so dis-torted that interpretation is difficult. The control officers have more efficient sets than the pilots have. Power is greater,and clarity of reception and transmission is better. The set in the aircraft is often working under adverse conditions. Oftenwater that has leaked through the joints in the cockpit drips on to the set or its remote controls, or into the headset jacksockets, producing a nose which I do not know how to tran- scribe on to paper, but which is far removed from intelligiblehuman speech. Control officers make this worse by gabbling off their instructions at high speed. Foreigners have thegreatest difficulty here, and if they would speak more slowly to all, their instructions would be less misunderstood, andsafety improved. On many aircraft sets one gets the impres- sion that the controller is sitting there at his desk eating hotchestnuts! To return to the subject of Accident Investigation, the otherweek in Malta I met an Accident Investigation Officer on his way to North Africa to investigate the loss of an aircraft losteleven months previously. This shows the organization wants pepping up more than somewhat. The M.C.A. costs us a lotof money—no wonder! Another Investigating Officer was heard to approach the wreckage of an aircraft with words tothe effect that this time we cannot blame the pilot. Normally, of course, they do. J. C. NEILAN. Sutton, Surrey. FORTHCOMING EVENTS Oct. 15th.—Second International Air Ball at London Airport. Oct. 15th.—Institute of Navigation : "Transverse Navigation, an Alter- native to the Grid System," W. A. W. Fox. Oct. 16th.—Wolverhampton Aero Club : The Siddeley Trophy Race. Oct. 21st.—Royal Aeronautical Society: "Cold Weather Operation of Aircraft,1' G. W. Wilson, A.F.R.Ae.S. and S/L E. P. Bridg- land, R.C.A.F., B Sc, A.F.R.Ae.S. Oct. 22nd.—Bristol and Wessex Aeroplane Club : Aviation Ball, Grand Spa Hotel, Bristol.
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