A-70-052
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FAA: (1) REQUIRE THE INSTALLATION OF A VASI SYSTEM AT ALL AIRPORTS USED BY LARGE, WIDE-BODIED JET TRANSPORT AIRCRAFT. (2) INITIATE ACTION TO INSURE THAT MODIFICATIONS ARE MADE TO THE PRESENT VASI SYSTEM SO AS TO MAKE THE SYSTEM MORE COMPATIBLE WITH THE CHARACTERISTICS OF LARGE, WIDE-BODIED JET TRANSPORT AIRCRAFT, YET RETAINING ITS UTILITY FOR THE SMALLER AIRCRAFT. CONSIDERATION OF THE PULSED LIGHT CONCEPT IS PARTICULARLY ENCOURAGED. (3) UNDERTAKE QUANTITATIVE RESEARCH INTO THE EFFECT OF RAIN ON THE WINDSHIELD IN ORDER TO DETERMINE MORE ACCURATELY THE FINITE RELATIONSHIPS BETWEEN THE AMOUNT OF RAIN AND THE DEGREE OF DISPLACEMENT BETWEEN THE REAL AND APPARENT POSITIONS OF OBJECTS VIEWED THROUGH A WATER-COVERED WINDSHIELD. (4) UNDERTAKE RESEARCH TO DETERMINE THE EFFECT OF CURVED WINDSHIELDS AND THE POSSIBILITY OF FALSE VISUAL CUES FROM MULTIPLE LIGHTS IN THE PERIPHERAL VISUAL AREAS. (5) DEVELOP AND REQUIRE IN THE COCKPIT DEVICES WHICH WOULD DISPLAY THE APPROACH PATH TO THE PILOT, IN THE ABSENCE OF EXTERNALLY ORIGINATED INFORMATION SUCH AS ILS, VASI, ETC. SUCH DEVICES, HOWEVER, MUST NOT APPRECIABLY INCREASE THE CREW COCKPIT WORKLOAD, NOR DISTRACT THE PILOT FROM PROPER USE OF HIS FLIGHT INSTRUMENTS.
In plain language (FlightFinder summary)
The FAA is asked to require VASI systems at all airports used by large, wide-bodied jet transport aircraft; modify the VASI system to better suit such aircraft while keeping it useful for smaller planes, with particular consideration of pulsed light; research how rain on windshields displaces the apparent position of objects; research the effects of curved windshields and false visual cues from peripheral lights; and develop cockpit devices that display the approach path when external guidance like ILS or VASI is unavailable, as long as these devices do not significantly increase crew workload or distract from flight instruments.
This plain-language summary is written by FlightFinder to explain the recommendation above. It is not the official wording — the verbatim NTSB text is quoted above.
Details
| Status | Closed - Acceptable Action |
|---|---|
| Mode | Aviation |
| Closed | Jun 29, 1972 |
| NTSB number | SEA70I0024 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).