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I believe that the 707/DC8 fleet represents the greatest problem and is the main source of complaints (for such major airports as JFK and Los Angeles). The first attached noise footprint chart illustrates this problem. I am not aware of any practical way to retrofit their current engines by nacelle treatment alone to achieve FAR36 noise. NASA is now financing a technology program to test a redesigned fan section for these engines which might show the technical feasibility of retrofitting the 707/DC8 with these quieter engines plus new nacelles and reversers. While we believe that it might be technically possible for such substantially modified engines and nacelles to meet FAR36, we believe this approach will prove to be a very poor investment for the industry and the Government. These airplanes are already obsolete.

A much better and proven solution to the 707/DC8 noise problems already exists in the DC10/L1011/ and 747 series of wide-body jets. These modern aircraft, incorporating the latest in noise reduction and smoke reduction technology have already been certified at noise levels below FAR36. The aircraft types using the General Electric CF6 engine in the 1971-1976 time period including the DC10-10, DC10-30, 747-300, and A300B have noise levels ranging from 3 to 7 EPnL below FAR36 on a traded basis. This is a huge improvement over the 707/DC8, as shown in the second chart attached, and is much quieter than is possible with 707/DC8 engines retrofitted with new fans, nacelles, and reversers. I believe that it would be much more sensible for the Government to find ways to accelerate the retirement of these old aircraft in the 1973-1978 period and replace them with the modern quieter aircraft available.

The smaller aircraft such as the 727/DC9/737 can be approached in a different way. We believe it is possible for this class of aircraft to have their nacelles modified in such a way that FAR36 can be met and that their noise footprints could be reduced with proper consideration of takeoff and approach aircraft operating procedures (such as power cutback and 2 segment approaches). Whether engine retrofit of the existing aircraft fleet is sensible is another matter-particularly if the dominant 707/DC8 noise can be handled by replacement with available quiet wide-body transports, and if 727/DC9/737 noise footprint areas can be ameliorated by operating procedures alone. With regard to the retrofitting of the 727/DC9/737 fleet with their existing engines rebuilt with new larger fans (development of which is now funded by NASA) plus new nacelles and reversers, we believe that this approach will also prove to be a very poor investment for its incremental noise improvement. Here again, it appears to me that the wiser and more effective solution lies in the new aircraft types using high bypass turbofans such as the CF6 or the new 20-25 000# thrust turbofans now under consideration which will replace the 727/DC9/ 737 fleet. Typical noise levels for such new aircraft are shown on the third chart.

These new twinjets and trijets in the 150-180 passenger short to medium haul category certificated in the 1976-1978 period may be able to meet FAR 36 minus 10 EPnL. Although this has not yet been achieved in an economically attractive way, it is our goal and we are making progress toward it. We consider FAR36 minus 15 EPnL

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out of reach for the 1970's, and furthermore, doubt that there is a need to achieve this level when operating from current airports.

In summary, I would like to emphasize that I believe that the real problem of resolving the current noise situation with respect to meeting FAR36 on any accelerated time schedule such as you propose is primarily one of economics-not technological. This real problem is not being addressed, in my opinion. The DC10/L1011/ and 747's can solve most of the public problem-the question is how to get many more of them in service sooner. Revised aircraft operating procedures can help 727/DC9/737 noise now, newly manufactured 727/DC9/737 could have nacelle treatment added and new types of short and medium haul twinjet/trijet transports with high bypass turbofans will completely solve the noise problem posed by this class of aircraft in the post 1976 period. The U.S. Government should concentrate more on helping to modernize the U.S. fleet with new wide-body high bypass turbofan powered transports than on the modification and retrofit of obsolete engines and aircraft. If such a solution can be found, it would be the best solution for noise, pollution, passenger comfort, U.S. sales/jobs/balance of trade, and the general health of the aircraft and airline industry.

Sincerely,

GERHARD NEUMANN.

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Senator JOHN V. TUNNEY,
Committee on Public Works,
U.S. Senate,
Washington, D.C.

GILBERT, SEGALL & YOUNG, New York, N.Y., September 14, 1972.

DEAR SENATOR TUNNEY: I have your letter of September 8, 1972 concerning S. 3342. Unfortunately, this did not reach me until yesterday, after being forwarded through Washington and New Jersey. You will recall that your letter was addressed to me as President of Rolls-Royce, Inc., 45 Rockefeller Plaza, New York, New York, 10020. Rolls-Royce, Inc. has since 1969 had no connection with aviation, and is strictly an importer and distributor of Rolls-Royce and Bentley motor cars. It has not been located at 45 Rockefeller Plaza for some years, and I no longer have any association with it or its parent company in England.

I am, however, U.S.A. counsel for Rolls-Royce (1971) Limited, of London, Derby and Bristol, England, which is the successor to the gas turbine business of Rolls-Royce Limited, and for its subsidiary, RollsRoyce Aero Engines, Inc., of which I am also a Director. The address of Rolls-Royce (1971) Limited headquarters is 14-15 Conduit Street, London WIA 4EY, England. The address of Rolls-Royce Aero Engines, Inc. is 551 Fifth Avenue, New York, New York 10017.

Since receiving your letter yesterday I have learned from Mrs. Frank and Mrs. Deller that the time schedule has been speeded up so that you require comments by Friday, September 15, 1972, rather than Monday, September 18. I had hoped to make a truly useful reply to your inquiry, but unfortunately the time is really too short to do this.

Perhaps, however, I can respond in a general way to certain aspects of your inquiry.

1. It would appear to me that noise limitations upon the operation of aircraft should remain with the Federal Aviation Administration rather than the EPA. I say this because the nature of the problem requires careful consideration of problems far beyond the normal concerns of the EPA. From the nature of the matters to which your letter addresses itself I infer that, to some degree, you may agree. I suggest, therefore, that the bill should not vest sole authority in the EPA, but should leave it primarily in the FAA which is currently engaged in very comprehensive studies of all aspects of the problem.

2. I would not think that it would be wise to provide by statute that no aircraft can land at U.S. airports after a fixed date unless certain specific noise level standards are met. Rather, I think that the authority to fix and enforce noise level standards should be left primarily to the FAA. To impose a rigid statutory rule with rigid dates would, to my mind, lead to very unfortunate complications, both with respect to the entire aviation industry and all U.S.A. commerce, and with respect to the commercial relations between the U.S.A. and foreign countries into which U.S. carriers fly.

3. Similarly, because of the complexity of the problem I would not think that the imposition by statute of arbitrary noise limits would be desirable. Rather, I would think that the best results would be obtained by leaving the matter primarily to the FAA, which is the

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expert public agency capable of taking into account all of the necessary considerations. Further, the dates and standards the bill would set appears to me to be very optimistic on the basis of present knowledge, though I recognize that predictions in this area are very difficult.

4. As to your specific inquiries, it is not possible on such short notice for me to give you useful responses. Beyond that, I do not believe that there is sufficient data presently available concerning retrofit, the cost of retrofitting, lead times and procedures respecting specific types of aircraft. One can only be sure that retrofit of older aircraft, including, as you suggest, new front fan treatment, would be enormously costly and disruptive, but it would be premature to make any dependable estimate along these lines. Rolls-Royce, of course, like other engine manufacturers, is expending great efforts with respect to those of its engines which power commercial aircraft. These include the Spey engine on the BAC 111 and Gulfstream II (efforts concerning the Spey being the subject of an article in Aviation Week for September 4, 1972), the Dart, which powers various types of aircraft, including the FD27, the Grumman Gulfstream I, the Viscount and others. The Conway engine, which is installed on the VC-10 and certain models of the Boeing 707 and Douglas DC-8, is not in service with any U.S. airline. All of the aircraft powered by Rolls-Royce engines do, however, utilize U.S. airports in international travel. The RB 211, which is installed on the Lockheed L-1011, is, of course, a new technology high thrust engine with outstanding noise characteristics, and it does not, I believe, fall within the ambit of your inquiry.

In a nutshell then, aside from my being able to make the remarks above, I do not think that there has been time enough to collect reliable data and to put it in a usable form for you. I am not at all sure that even if more time were available I would be able to give you comparative costs of retrofit and retirement and replacement, nor do I believe that I could make informed comments concerning aircraft which are powered by engines other than Rolls-Royce. I regret that I cannot do more at this time. If developments are such and the time available is expanded so that we can be of assistance in the future, and if we can be given sufficient advance notice to permit the development of appropriate data, we shall certainly do our best to assist you in any way we

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DEAR SENATOR TUNNEY: We at Lockheed have been doing everything in our power to see that our new L-1011 transport has as low a level of noise as can practically be reached, and we are working hard with propulsion manufacturers and NASA seeking out any new ideas which will improve urban acceptability of future airplanes. I think

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