§ 2.37 p.m.
§ LORD OGMOREMy Lords, I beg to ask the Question which stands in my name on the Order Paper.
§ [The Question was as follows:
§ To ask Her Majesty's Government whether they are satisfied that any altimeter available for civil aviation gives accurate readings; what steps they are taking to ensure that altimeter dials are clear and are not liable to be misread by pilots, and what warnings to pilots have been given by the Ministry of Transport and Civil Aviation of the possibility of inaccuracy of altimeters and of error in altimeter readings.]
THE EARL OF GOSFORDMy Lords, altimeters fitted in United Kingdom registered aircraft are subject to the approval of the Air Registration Board. This approval ensures that the performance of the instruments is within acceptable tolerances and that the highest practicable standard of accuracy is achieved. The types of altimeter in current world use are operated by barometric pressure and have certain inherent limitations. But one of the requirements, prior to a pilot's obtaining a licence, is that he should have knowledge of the operating principles and 574 of the errors and limitations of all his instruments including altimeters.
As a result of urgent studies carried out by the Ministry of Transport and Civil Aviation and by the Air Registration Board, modifications to the dials of existing types of altimeters have been devised. As currently approved, these incorporate a low-level warning flag, and a distinctive white line to emphasise the position of the 10,000 feet pointer which together should help to reduce ambiguity. Photographs showing the modifications will be available in the Library. Air Registration Board Notice No. 54, issued on February 16, 1959, requires that modifications on these lines should be made by September 30 this year to altimeters used on Britannia, Comet and Viscount aircraft and on other aircraft operating above 20,000 feet.
Furthermore, a committee has also been set up by my right honourable friend the Minister of Transport and Civil Aviation to investigate the design of altimeter faces and mechanisms, including the use of special visual or audible signals, and this committee will make recommendations for the design requirements best suited to modern needs for quick and easy recognition of altitude readings. The committee comprises representatives of the principal interests concerned, including the Air Registration Board; the Air Ministry; the Ministry of Supply; the Society of British Aircraft Constructors; the Operators; and the Pilots' and Navigators' Associations.
The fact that care must be taken in reading altimeters has been well known to pilots for many years. However, since two more recent accidents have indicated that with present high flying and fast aircraft misreadings are more likely, Information Circular 20/1959 has been issued to re-emphasise the need for care. I should like to end by thanking the noble Lord, Lord Ogmore, for having postponed his Question until to-day, at my request, for medical reasons.
§ LORD OGMOREMy Lords, while thanking the noble Earl for that long and detailed Answer, may I ask him whether the Government are satisfied that the present altimeters give a correct indication of the height of aircraft at all times?
THE EARL OF GOSFORDMy Lords, the noble Lord has certainly posed me a 575 question there. As I said at the beginning of my Answer, altimeters as at present designed, which work on barometric pressure, are always subject to certain fluctuations of air pressure. But so far as I think the noble Lord is referring to the question of reading or, rather, the misreading of altimeters by as much as 10,000 feet, I would point out that their inaccuracies are certainly nothing of that order.
§ LORD OGMOREMy Lords, in view of the fact that nearly all air highways are based upon a height, is it not absolutely essential that all concerned in the aircraft industry should do their best to give the pilot an accurate indication of what his height is? That is my point.
THE EARL OF GOSFORDMy Lords, on that there is no doubt. A pilot is given the barometric pressure, and without going into long details (which I can explain to the noble Lord afterwards) I can say that he is accurate as to his height within 10 or 20 feet.
§ LORD SHEPHERDMy Lords, may I ask the noble Earl whether the modifications carried out on the altimeters for the civil airliners, Britannias and Comets, are also to be brought in far the Royal Air Force Training Command and for the bomber fleet?
THE EARL OF GOSFORDMy Lords, I regret to say that I have not the answer to that question. I will certainly find out and let the noble Lord know.
§ EARL HOWEMy Lords, may I ask the noble Earl whether we are to understand from his original Answer that the new regulations, or new instruments, will not come into force until September 30? What happens between now and then?
THE EARL OF GOSFORDMy Lords, we carry on as we have carried on for the last—is it fifty years of flying? After all, when we think of the millions of miles that have been flown by aircraft, and the number of aircraft flights that have taken place over all the years since flying started, the number of accidents which have, in fact, been caused by this 576 misreading of an altimeter is almost negligible
§ EARL HOWEMy Lords, while I appreciate that point, I think I am right in saying (indeed, I think the noble Earl said it) that there have been two serious accidents lately—one very serious one indeed, which might have resulted in the loss of the Turkish Prime Minister. Surely this defect, which has been well known for years, should be stopped, if possible, before September 30?
THE EARL OF GOSFORDMy Lords, I do not think the accident to the Turkish Prime Minister had anything to do with this particular argument. That occurred for a quite different reason. The misreading of an altimeter by the amount of 10,000 feet is really a new phenomenon, produced by the speed at which things happen nowadays in the cockpit of an aircraft.
§ LORD PETHICK-LAWRENCEMy Lords, can the noble Earl assure us that, although the date of September has been fixed as the date by which all these alterations are to be made, in the meanwhile, and as quickly as possible, a great many of the instruments will be altered to accord with the new regulations so that no unnecessary delay is involved?
THE EARL OF GOSFORDI have no doubt that these alterations are being made; but I should like to emphasise again that these pilots are all experienced men, who know and understand and fly by their instruments, day in and day out, hundreds of thousands of miles daily, and that these accidents are very rare occurrences indeed.
§ THE EARL OF LUCANThe noble Earl, in his original Answer, said that the measures proposed would reduce ambiguity. Surely the Government's object should be to remove all ambiguity?
THE EARL OF GOSFORDIf the noble Earl would like to meet me afterwards, I will try to explain to him exactly what the technical difficulties are, but I cannot possibly give him now a simple answer to his question on what is, in fact, a very complicated subject.