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Safety Recommendation Details

Safety Recommendation A-70-009
Details
Synopsis: MIDAIR COLLISION DC-9, PIPER PA-28 OVER FAIRLAND, INDIANA ON 9/9/69, INVESTIGATIONS INTO THE FACTS AND CIRCUMSTANCES OF THE ABOVE MIDAIR COLLISIONS,THAT OCCURRED IN RADAR TERMINAL AREAS BETWEEN LARGE, HIGH PERFORMANCE AIR CARRIER AIRCRAFT AND SMALL GENERAL AVIATION AIRCRAFT REVEALED THAT IN ONE CASE THE SMALL AIRCRAFT WAS NOT DETECTED BY THEAIR TRAFFIC CONTROLLER, AND IN THE OTHER, IT WAS DETECTED AND SUBSEQUENTLY LOST.
Recommendation: BOARD HAD RECOMMENDED THAT PARTS 21 AND 23 OF THE FAR BE MODIFIED TO REQUIRE ALL AIRCRAFT UNDER 12,500 LBS., MANUFACTURED AFTER SOME APPROPRIATE DATE, TO POSSESS A RADAR CROSS SECTION SUITABLE FOR PRIMARY TARGET DETECTION. THE BOARD WAS NOW OF THE VIEW THAT A MORE APPROPRIATE REGULATORY APPROACH WOULD BE TO AMEND PART 91 OF THE FAR'S TO REQUIRE ALL AIRCRAFT OPERATING IN RADAR SERVICE ENVIRONMENTS TO HAVE A MINIMUM LEVEL OF RADAR CROSS SECTION. SUCH ACTION WOULD MAKE IT POSSIBLE FOR SOME OPERATORS, NEVER INTENDING TO OPERATE IN RADAR ENVIRONMENTS, TO AVOID THE NECESSITY OF REFLECTIVE AUGMENTATION.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Unacceptable Action
Mode: Aviation
Location: Fairland, IN, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA70A0004
Accident Reports: Allegheny Airlines, Inc., DC-9, N988US, and a Forth Corporation Piper PA-28, N7374J
Report #: AAR-70-15
Accident Date: 9/9/1969
Issue Date: 1/23/1970
Date Closed: 1/11/1974
Addressee(s) and Addressee Status: FAA (Closed - Unacceptable Action)
Keyword(s):

Safety Recommendation History
From: FAA
To: NTSB
Date: 3/22/1972
Response: -From K.M. Smith, Acting Administrator: You will recall our exchange of correspondence with respect to the accident report adopted by the National Transportation Safety Board regarding the Allegheny Airlines DC-9 and Piper Cherokee midair collision of 9 September 1969 near Fairland, Indiana. Since those letters, our further investigation of the circumstances of this accident has disclosed additional facts which we believe should be considered by the Board with a view towards an appropriate reinvestigation of the accident and revision of the accident report. In determining that the probable cause of this accident was the deficiencies in the collision avoidance capability of the Air Traffic Control system, including "the inadequacy of the see-and-avoid concept under the circumstances of this case," the Board relied on the apparent fact that the DC-9 was descending through clouds just prior to the collision so that neither the Piper Cherokee pilot nor the Allegheny crew had sufficient time to see and avoid the other aircraft. The Board Report referred to a consensus of several studies that "15 seconds is the absolute minimum time for detection, evaluation, and evasive action. Your 9 November 1970 letter stated that the total time available to the Allegheny crew and the Piper Cherokee pilot was 14 seconds. We are enclosing copies of written statements by 15 eyewitnesses to the flight of the DC-9 prior to the collision. Most of these eyewitnesses were located at the Triton High School which is approximately 1.9 miles east of the collision point. The DC-9 was on a westerly heading. The unanimous observations of these witnesses is that the DC-9 was being operated in full view, below any clouds, prior to the collision. Their observation points and their recollections of the amount of time they were able to observe the DC-9 compel the conclusion that the DC-9 crew should have seen the Piper Cherokee for at least 30 seconds prior to the collision. In view of the above, we request that the Board conduct a reinvestigation and appropriately revise its report in the light of the results obtained in that reinvestigation. That revision should include a correction of the basic finding that "there was insufficient opportunity for either crew to reasonably be expected to see and avoid the other's air-craft" and an amendment of the determination of probable cause. You may also wish to delete the erroneous finding that the Piper Cherokee was operating with a VFR clearance and, also, to clarify the references to "positive radar control", "passive control" and "active control." Thank you for your consideration of this matter.

From: FAA
To: NTSB
Date: 11/23/1970
Response: -From J.H. Shaffer, Administrator: Upon reading the 9 November 1970 reply of the National Transportation Safety Board to our analysis of the Fair-land accident report, I thought it was a fairly responsive reaction until I refreshed my memory by reviewing our 10 September 1970 and 2 October 1970 letters to you. Your letter concludes by stating that a copy, together with a copy of our 2 October 1970 letter, will be entered into your docket in this investigation. Since you have already placed a copy of our 10 September 1970 letter in the docket, the docket will now contain a full statement of our position with respect to the Board accident report and anyone reviewing the docket will be in a position to make his own judgment regarding the fairness and adequacy of the Board response to the FAA position. Thank you for your courtesy in giving us an opportunity to present our detailed views in this matter.

From: FAA
To: NTSB
Date: 10/2/1970
Response: -From Oscar Bakke, Acting Administrator: This is in response to your September 15 denial of our request for a postponement of the public release of the Board accident report on the midair collision near Fairland, Indiana. You base your denial on the absence of any provision in the Board procedures for postponing the report. Your reason for denying our request is surprising since your predecessor Board granted an earlier request by FAA of an identical nature under the same procedural regulations, with respect to the 8 February 1965 accident near Jones Beach, New York. Upon recalling that report prior to publication, the Board granted the FAA a hearing on the matter and then issued a revised report. Your letter suggests that we analyze in depth the Fairland report and the "other Board reports referred to" in our letter, and then formally request reconsideration of the Board conclusions and probable cause. While we are pleased to accept your suggestion, we cannot resist noting that it conflicts with your denial of our initial request since the Board procedural regulations similarly lack any provision for the Board entertaining such a request for reconsideration. Prior to making our postponement request, we had compared the Fairland report with the only other Board report referred to in our letter, the one on the Urbana, Ohio midair collision of 9 March 1967. Accepting the facts as they are stated in the two Board reports, we offer the following comparison accompanied by our comment: AIRCRAFT Urbana: Air carrier DC-9 and a Beech Baron BE-55. Fairland: Air carrier DC-9 and a Piper Cherokee PA-28. (Comment: No substantial differences in the aircraft involved in the one accident as compared to the other.) WEATHER Urbana: Clear visibility six or seven miles, a haze layer, snow coverage of 80% to 90%. Fairland: Visibility in excess of 15 miles, no haze, no Snow coverage. (Comment: Weather conditions in the Fairland accident were more favorable for the detection of other aircraft.) FLIGHT PATHS Urbana: The DC-9 was descending at 3500 feet per minute for 20 seconds, and overtaking and converging on the Beech Baron from the left. The Baron was level at approximately 4500 feet MEL. Fairland: The DC-9 was descending at approximately 2400 feet per minute and converging from the left while the Cherokee was converging from the right. The Cherokee was level at approximately 3500 feet MSL. (Comment: The rate of descent of the DC-9 in the Fairland accident was substantially less than the rate of descent of the DC-9 in the Urbana accident.) SPEED Urbana: The DC-9 was operating at 323 knots while the Baron was operating at approximately 193 knots. Fairland: The DC-9 was operating at a gradually increasing airspeed from 236 knots to 256 knots with the Cherokee operating at 107 knots. (Comment: The speed of the DC-9 in this accident was substantially less than the DC-9 in the Urbana accident.) COLORS Urbana: The DC-9 had a white top, a red stripe on the fuselage, a black radome, the rest unpainted aluminum. The Baron's wings and lower half of the fuselage were painted red and the upper half painted white. Fairland: Aircraft colors are not mentioned in the report. (Comment: The absence of any reference to aircraft color in the Fairland report indicates that no study was made nor consideration given to the conspicuity aspects of the aircraft colors in this accident.) AIR CARRIER CREW Urbana: The Copilot was flying the DC-9 from the right seat and the Captain was handling the communications in the left seat. Fairland: The Captain was flying the aircraft from the left seat and the Copilot was handling communications. (Comment: In the Fairland accident, the individual with the greatest freedom to observe was in the seat closer to the other air craft.) APPROACHING ANGLE Urbana: The Baron was approximately 300 to the right of the DC-9 path and closer to the Copilot flying the aircraft from the right seat. The DC-9 was approximately 950 to 1000 to the left of the Baron's path requiring a turn of the head beyond 900 to see the DC-9. Fairland: The Cherokee was approximately 190 to the right of the DC-9 path and closer to the Copilot who was not flying the airplane. The DC-9 was approximately 550 to the left of the Cherokee's path. (Comment: In the case of the Fairland accident the angles of convergence were far more favorable for observation of the other aircraft than in the Urbana accident where, however, the DC-9 pilots had received a traffic advisory on the Beech Baron.) TURNS Urbana: The DC-9 could have been in the process of making a 100 left turn while the Baron was on a constant heading. Fairland: Both aircraft were on constant headings for at least 22 seconds prior to impact. (Comment: A turning situation was not involved in this accident but apparently was in the Urbana accident. The Board notes in the Fairland report that a turning situation will diminish a pilot's ability to locate other aircraft.) PILOT ACTION Urbana: There was no evidence of attempted evasive action by either crew. Fairland: There was no evidence of attempted evasive action by either crew. AVAILABLE TIME Urbana: A period of 14 seconds was available for the observation of the other aircraft and the accomplishment of evasive action. Fairland: A period of 14 seconds was available for the observation of the other aircraft and the accomplishment of evasive action. (Comment: In the Urbana report, the Board concludes that approximately 5 seconds would have been sufficient for the DC-9 crew to detect the other aircraft and initiate a change in direction of the DC-9,and that the DC-9 response time would have been approximately 3 seconds.) While the above comparison of the pertinent facts of the two midair collisions demonstrates that the pilots involved in the Fairland accident had more opportunity to detect and avoid the other aircraft than the air carrier pilots in the Urbana accident, the Board nevertheless concludes that no pilot was responsible for the Fairland accident, after having concluded the air carrier pilots were responsible for the Urbana accident. The reasoning presented in the Fairland report does not provide persuasive support for the absolution of the pilots from responsibility for this accident. The Board report baldly states that the DC-9 Captain's ability to observe the other air craft was "virtually nil." This conclusion is apparently based on the cockpit visibility study which used the Douglas design eye position for the Captain and found the Cherokee obscured by the aircraft structural member between the Captain's front windshield and the center windshield. No evidence of the Captain's physical characteristics is provided to show that his eye position would correspond to the design eye position. The Board conclusion also assumes the continued maintenance of a dummy-like posture by the Captain throughout the 14-second period and is thus contrary to the normal reaction expected of a pilot upon emerging from clouds while descending. In such circumstances, we submit it is more realistic to conclude that the Captain should have immediately initiated a comprehensive scan of his area of operation, detected the Cherokee within 5 seconds, and had the DC-9 responding to evasive action within another 3 seconds. The Board's excuse for the first officer's failure to observe the Cherokee, i.e. the air carrier requirement that he call the altitude as the aircraft passed through 3500 feet, is based on the conclusion that he was thereby "required to monitor the altimeter for a few hundred feet prior to reaching the altitude in order to note passage" and that the airspace involved for high rates of descent in approach areas should, accordingly, be protected by "positive air traffic control procedures." This reasoning, and the conclusion it supports, does not give proper consideration to the surveillance that a reasonably prudent pilot should perform upon emerging from clouds. In addition, it means that any crew member charged with the responsibility of calling out an altitude is excused from maintaining a surveillance outside the aircraft and that the aircraft must be protected completely by air traffic control. I believe the mere statement of this proposition accurately demonstrates the extent to which the Board is reaching in this report to excuse pilots from the responsibilities placed on them by the Federal Aviation Regulations. The Board's conclusion here with respect to the "see-and-avoid" responsibilities under the FARs would apparently also apply to instructions given the pilots by the employing air carrier. An excerpt from the Flight Operations Manual of the carrier was included in Exhibit 2A, the Operations Group Chairman's Factual Report of Investigation. That excerpt emphasizes the responsibility of pilots to maintain surveillance for other traffic. It reads as follows: "Prior to and during the takeoff and climb, as well as throughout flight operations, pilots shall maintain a sharp watch for other traffic. This is especially true when operating in VFR conditions. The fact that a flight is operating under Instrument Flight Rules does not alleviate pilots from the responsibility of observing Visual Flight Rules when in VFR conditions. VFR responsibility is geared to the type of condition, not the type of flight plan. As little cockpit paper work as practicable shall be done during climb or descent." The Board's analysis of the operation of the Cherokee is somewhat scanty. It notes that the pilot, operating "only 500 feet below the clouds," would be unable to see the DC-9 until it emerged from the clouds. The Board then proceeds to the finding that there was insufficient opportunity for the Cherokee pilot "to reasonably be expected to see and avoid" the DC-9. This reasoning assumes that an operation conducted in marginal compliance with the FARs and without regard to other circumstances must be judged in every case to be a safe and proper operation. The reasoning also omits any consideration of the judgment of the pilot in selecting and pursuing an operation which would have his aircraft only 500 feet below the clouds in an area where other aircraft would be descending to a major airport. The other exercise of judgment by the Cherokee pilot which appears relevant and material to this accident but yet was not given any consideration by the Board was his failure to utilize the expanded radar service of Indianapolis Approach Control. The Board report contains a reference to other VFR aircraft utilizing this service at the altitude and within the time span involved in this accident but omits any discussion of the non-use of the service as a possible factor in the accident. If the Cherokee pilot had contacted Indianapolis Approach Control, reported his position and requested traffic information, the traffic advisories furnished would have undoubtedly included the DC-9. Also, this report would have enabled Approach Control to advise the DC-9 of his altitude, course and position. No basis appears in the report for the Board conclusion that the Cherokee pilot was operating in full compliance with the FARs. These regulations impose the "see-and-avoid" responsibility. Assuming the shortest time span provided of 14 seconds to avoid the DC-9, a proper watch outside the Cherokee cockpit would have permitted at least partial, if not complete, evasive action and the physical evidence of the collision does not indicate any evasive action was ever initiated. We note the use in the report of the term "positive radar control" and the introduction into aeronautical use, with-out definition, of the terms "active control" and "passive controll1 of the air traffic control system. The only positive radar control provided by the FAA is at the higher altitudes, flight level 180 and above in the Indianapolis area, where all aircraft are operated IFR and provided positive separation. The references to ATC active and passive control are particularly misleading in view of the Board's conclusion that the ATC system, not the pilots, was responsible for this accident. While we are uninformed as to whether the Board would place our expanded radar service under the "active" or "passive" category, the fact remains that this part of the ATC system was not being utilized, accordingly, we do not believe this accident may form a basis for concluding the ATC system is the probable cause. In this respect, we should note that this accident represents the only midair collision involving an air carrier or commercial operator aircraft in which one of the aircraft had emerged from clouds shortly before the collision. We have long been aware that there are circumstances which make difficult the compliance by pilots with their "see-and-avoid" responsibility. In the course of our presentation at your hearing of 6 November 1969, we listed 30 programs which FAA had accomplished to reduce the midair collision hazard. We also described 18 projects in which we were then engaged to reduce the midair collision hazard. Further, we summarized 17 programs we planned to undertake to reduce this hazard. We can now advise you that either progress is being made with these projects or they have been accomplished. The results are presently being employed either to lessen the potentiality of the collision hazard or to improve the ability of the pilots to cope with it. We will not repeat here the statements of principle regarding the possible derogatory effect of the report on aircraft operations within the ATC system as it is now being operated and must continue to be operated for a substantial period into the future. It is our belief that it is incumbent upon the entire aviation community to devote its best efforts in ameliorating the midair collision hazard. With those best efforts, and the increased resources becoming available to us, we forecast a continued improvement in aviation safety. In summary, we believe that the facts of this accident, as accepted by the Board in its report, do not provide a substantial basis for the Board determination that the probable cause was the ATC system but, rather, they more logically support a determination that the accident was due to deficiencies in the judgment and the performance of their surveillance responsibilities on the part of the pilots involved. The determination of probable cause and the relevant findings in the report should be revised accordingly. In reaching its conclusion that the ATC system was responsible for this accident, the Board stated in its report that "it was recognition of the vast scope and far-reaching effects of this conclusion that prompted the Board to conduct a public hearing on the Midair Collision Problem." The announcement that the Board intended to conduct a public hearing on the Midair Collision Problem was made by the Presiding Officer of the Fairland accident hearing on 7 October 1969, prior to the commencement of that hearing. Thus, it follows that the conclusion expressed in the Fairland accident report on the culpability of the ATC system for the Fairland accident was reached by the Board prior to the public hearing on the Fairland accident. We suggest that in cases of accidents where the Board has made its determination regarding the probable cause of the accident prior to the hearing, the Board does the public and the participating parties a disservice in holding the hearing. Since a hearing is not mandatory in the accident investigative procedure, it appears desirable in future cases of this type that a hearing not be held and that the Board simply publish its report. This course of action would not only save the time and effort of the participating parties but should expedite publication of the report. Thank you for the opportunity to record our views on this subject.

From: FAA
To: NTSB
Date: 9/10/1970
Response: -From J.H. Shaffer, Administrator: I have today reviewed the Aircraft Accident Report adopted by the National Transportation Safety Board for release 11 September 1970 on the midair collision which occurred between an Allegheny DC-9and a Forth Corporation Piper PA-Z8 near Fairland, Indiana, on 9 September 1969. I am greatly concerned that the "Probable Cause" stated in this Accident Report could have a very derogatory effect on aviation safety. Consequently, I ask that release of the Report be postponed, and that the Federal Aviation Administration be afforded an opportunity to challenge the reasoning and conclusion contained in it. The Probable Cause of this midair collision is stated to be the deficiencies in the collision avoidance capability of the FAA air traffic control system, including the inadequacies of the see-and-avoid concept, the technical limitations of radar, and the absence of regulatory separation of VFR and IFR traffic in terminal areas. Nationwide, none of the possible remedies for these so-called deficiencies; i. e., elimination of "see-and-avoid, " perfection of radar, or national adoption of regulations separating VFR and IFR traffic, is possible of achievement within the near future. As you know, we are now in the process of introducing the first terminal control areas which achieve separation of VFR and IFR traffic, both through the application of ATC procedures and through regulatory means. With regard to radar, there is no current method available for perfecting radar to cure the limitations outlined in your report. We would like to emphasize one point--we do not consider the "see and-avoid" concept totally unacceptable on a nationwide basis. We do feel that it is becoming increasingly obsolescent in high density traffic areas, or in areas where the rates of closure between aircraft are consistently high. This is the basis for both the TCA concept and the area positive control concept in the enroute environment. The latter program covers virtually the entire nation at high altitudes. As I am certain you and your staff well know, the solutions to most of the problems we currently have –additional and improved equipment and more personnel--lie in the improvements which, for the first time, are achievable under the recently enacted "Airport-Airways" Bill. The condemnation in this Report of the ATC system virtually relieves flight crew members of their current responsibility to maintain a lookout for other aircraft and to observe the right-of-way regulations. The "Probable Cause" compromises the current cooperative nature of the air traffic control system and the mandatory effect of the present Federal Aviation Regulations. The overall effect of the Report will be a confusion of the respective responsibilities of pilots, on the One hand, and of controllers and the ATC system on the other. The Board reasoning in the Report does not include appropriate consideration of the responsibilities of the pilots operating the two aircraft and their failure to fulfill those responsibilities. Accepting the Board's estimate of the availability of 14 seconds on the part of each pilot to see and avoid the other aircraft, we note that the Board does not discuss the lack of reasonable care on the part of (1) the air carrier pilots in failing to scan immediately their area of operation upon breaking out of the clouds and (2) the student pilot in operating approximately 500 feet below the clouds in an area of descending traffic without maintaining constant vigilance for such traffic. No mention is made of the fact that the student pilot had available to him, but did not use, the expanded radar service provided by the Indianapolis Tower. This service is made available for the express purpose of assisting pilots to see and avoid aircraft. We note that this Accident Report is inconsistent with the Report adopted by the Board on the midair collision between a Trans World Airlines DC-9 and a Tann Company Beechcraft Baron B-55 near Urbana, Ohio, on 9 March 1967. The circumstances of that accident were very similar to those involved here but the Probable Cause adopted by the Board in that case was the failure of the air carrier crew to see and avoid the other aircraft. The Report under discussion completely exonerates the air carrier pilots and the student pilot with the only apparent differentiation being the discussion in this Report of study reports published in 1954, 1955 and 1958, on the subject of midair collision prevention. With regard to FAA's more recent Near Midair Collision Report of 1968 and the subsequent NTSB report on midair collisions, it should be pointed out that varying degrees of action are underway to carry out the recommendations made in both reports. Eight of the 14 recommendations in your report were directly covered in our report; the remainder were indirectly covered in our report, except for one. It pertained to a reevaluation of visual conspicuity standards for civil aircraft. After extensive research, the use of exterior paint patterns was abandoned as not being effective against all backgrounds and under the variety of in-flight lighting conditions. In the event you are willing to accede to our request, we will be pleased to present ourselves at your earliest convenience for a discussion of this Report.

From: FAA
To: NTSB
Date: 8/13/1970
Response: -From K.M. Smith, Deputy Administrator: This is in reply to your letter of 7 July 1970 relative to the use of passive reflectors and acknowledges participation in the 28 April 1970 briefing to which you refer. In a practical manner, there was no passive device presented at that briefing that would achieve your stated goal of adequate primary target returns on ATC radar at 125-150 miles range. We will expedite our R&D efforts in this matter hoping to develop a practical enhancement device. In a related action to improve radar detection of small aircraft in terminal areas, FAR 91.90 as amended by Amendment 91-78, effective 25 June 1970, requires operable transponders on all airplanes operating VFR or IFR within the Group I designated terminal control areas. FAR 71 as amended by Amendment 71-6, effective 25 June 1970, defines the list of the nine Group I designated terminal control areas. The requirement for transponders was implemented at Atlanta effective 25 June 1970 and is scheduled for implementation at Washington, D. C., and Chicago O'Hare on 20 August 1970.

From: FAA
To: NTSB
Date: 4/10/1970
Response: -J.H. Shaffer, Administrator: Your letter of 19 March 1970 has been received. We are pleased to note that your comments are favorable. The following is in response to the third paragraph of your letter using the same numbered sequence: 1. As stated, we are preparing to amend the Federal Aviation Regulations (FARs) to require reporting of additional flight safety incidents and plan to delete from the regulations the operator's option to file such reports. We have a current study in effect that should be completed by 1 November 1970. It will then take another 18 months to two years to complete the regulatory changes to reflect the findings of the study. 2. We need to further discuss the inclusion of operational incidents into the Maintenance Analysis Center (MAC) system. We will be pleased to meet with your representatives in this regard at your convenience. 3. We have now prepared a specification for the Automatic Data Processing of Mechanical Interruption Summary information and have a first printout target date before the end of 1970. 4. Risk factor assignment and evaluation criteria improvement are continuing parts of each of the MAC's Automatic Data Processing programs, as well as efforts to get closer to the computer as to the time it takes from inquiry to answer. On the second page of your 19 March 1970 letter, there is mention of operational data and a reference to your letter dated 13 December 1968 which recommended an operational incident reporting system. Our letter to you dated 14 January 1969 responded to these items. We feel that prior to the implementation of a program such as this, it is necessary that we have further discussion regarding the information desired and methods to defray costs and manpower involved. We sincerely hope that we can be of service to the needs in this area and will be pleased to cooperate insofar as is possible.

From: FAA
To: NTSB
Date: 2/11/1970
Response: 2/11/70 FAA stated they are actively working with industry to develop methods and devices to enhance radar detection of light aircraft. To their knowledge, no suitable passive radar reflectors are available for small aircraft, neither has an acceptable application of passive reflectors been demonstrated on small metal skin aircraft. They requested information from the board on any new promising devices for radar enhancement that may be tested in their facilities. As soon as an acceptable approach to radar target enhancement is found, they will consider regulatory action to make radar enhancement devices a requirement. Note: on 4/28/70 representatives of six manufacturers of passive reflectors presented a briefing to the board. FAA attendees included personnel of their research and development staff dealing with radar and their accident investigation staff. 8/13/70 the FAA stated that in a practical manner, there was no passive device presented at that briefing that would achieve adequate primary target returns on ATS radar at 125-150 miles range. They will expedite their R & D efforts in this matter hoping to develop a practical enhancement device. In a related action to improve radar detection of small aircraft in terminal areas, far 91.90 as amended by amendment 91-78, effective 25 June 1970, requires operable transponders on all airplanes operating VFR or IFR within the group I designated terminal control areas. FAR 71 as amended by amendment 71-6, effective 25 June 1970, defines the list of the nine group I designated terminal control areas. The requirement for transponders was implemented at Atlanta effective 25 June 1970 and is scheduled for implementation at Washington, D. C., and Chicago O'Hare on 20 August 1970.