NTSB · Safety Recommendation
Safety Recommendation A-69-032
Recommendation
(1) THAT SECTION 91.116 OF THE F.A.R. BE CHANGED TO AGREE WITH THE PROVISIONS OF SECTION 121.653 AND THE SIMILAR REQUIREMENTS OF PARTS 123 AND 135 IN ORDER THAT THE APPROACH BE RESTRICTED AS WELL AS THE LANDING. (2) THAT SECTION 91.117 BE AMENDED TO THE EFFECT THAT IN NO EVENT SHALL DESCENT BELOW 200 FEET BE PERFORMED UNLESS LANDING MINIMA ARE PRESENT. (3) THAT WHILE SECTION 91.116 (B) CLEARLY STATES THAT A LANDING MAY NOT BE MADE UNLESS THE VISIBILITY IS AT OR ABOVE THE LANDING MINIMUM REQUIRED, NEVERTHELESS, IN THE INTERESTS OF SAFETY AND IN ORDER TO INSURE PROPER INTERPRETATION, ALL CONDITIONS REQUIRING A MISSED APPROACH SHOULD BE CONTAINED IN SECTION 91.117 (B).
ACCORDINGLY, AN ADDITIONAL CONDITION SHOULD BE ADDED TO SECTION 91.117(B) TO THE EFFECT THAT IF LANDING MINIMA CANNOT BE MAINTAINED, A MISSED APPROACH MUST BE EXECUTED.
Safety Issue and Context
N142D, A DOUGLAS DC-3, WAS BEING OPERATED BY MR. WILLIAM JACKSON OF TRAVEL ASSOCIATES, MEMPHIS, TENNESSEE, FOR THE PURPOSE OF TRANSPORTING SPORTSMEN TO BELIZE, BRITISH HONDURAS. THE AIRCRAFT CRASHED AND BURNED ON NEW ORLEANS INTERNATIONAL AIRPORT FOLLOWING AN INSTRUMENT LANDING SYSTEM (ILS) APPROACH TO RUNWAY 10. THE CRASH OCCURRED AT 0655 C.S.T. 1/ ON MARCH 20, 1969. OF THE 27 PERSONS ON BOARD, 11 SURVIVED. THE CREW OF THREE WAS AMONG THOSE FATALLY INJURED. THE AIRCRAFT CAME TO REST AT THE INTERSECTION OF RUNWAYS 5 AND 10. WITH THE EXCEPTION OF THE RIGHT WING AND EMPENNAGE, THE AIRCRAFT WAS DESTROYED BY IMPACT AND FIRE.
Response History
December 12, 1969 · Recipient Response · FAA
The recommended change was incorporated in the proposed changes to sec 91.116 contained in NPRM 72.17. The contents of the NPRM are undergoing drafting for inclusion in the far. The recommended change was included in the proposed changes to sec 91.117 contained in nprm72-17. The contents of the NPRM are undergoing drafting for inclusion in the far. The FAA, in a letter dated November 17, 1972, stated that they disagreed, "with the previous NTSB proposal to modify far 91.117b to make sighting of the runway a requirement for continuation of an approach below 200."
January 10, 1969 · NTSB Correspondence · FAA
-From Joseph J. O’Connell, Jr. Chairman: Within the past 6 months, we have investigated five accidents in which an aircraft struck ground objects or crashed short of the runway threshold while executing an instrument approach where visibility had been reduced substantially by fog. The weather conditions which obtained and the type of approach being conducted in these five cases are summarized in the enclosure to this letter.
We have reviewed a number of studies relating to the problems encountered in conducting low visibility approaches. Of particular interest were the many references to hazards associated with the penetration of shallow fog. These references include, among other things, discussion of:
1. The rapid reduction in the visual guidance segment available to the pilots if the fog is both shallow and dense; 2. The possibility that the pilot may mistake the reduction in light and the guidance segment as a change in pitch attitude in the nose-up sense, and 3. The lack of adequate visual clues relating to pitch attitude and aircraft height until the aircraft is less than 100 feet above the approach light or runway level. There is in addition, evidence that, even at this low altitude, pitch information is inadequate unless the runway threshold also is in sight:
Problems associated with shallow fog penetration were discussed at the public hearing conducted in connection with the Piedmont Airlines Accident at Charleston, West Virginia, on August 10, 1968. These discussions, and subsequent conversations with line and company pilots of four other air carriers, revealed that air carrier formal ground school and recurrent training programs do not include specific discussions on shallow fog penetration, the effect on the guidance segment, or the illusions that may be created in the pilot’s mind. The Board was also informed that a simulator capable of providing training in low visibility approaches presently does not exist.
Despite the above considerations, present Part 91 of the Federal Aviation Regulations permits an instrument approach to continue below the published and approved minimum descent altitude or decision height so long as the pilot has some ground object in sight which can be identified with the end of the runway. The pilot is, of course, expected to execute a missed approach if he loses sight of this ground object. However, the decision to continue or abandon the approach is likely then to be made at an altitude where either course of action is dangerous. That this situation is indeed hazardous is confirmed by the recent undershoot accidents. In view of the foregoing, the Board recommends: 1.