Figure: Typical microburst wind field, from NTSB Report, Figure 4.

Eddie Sez:

Ten years after Eastern Air Lines 66 and three years after Pan Am 759, many pilots were still not giving windshear the necessary respect it deserves. This crew flew into a thunderstorm on final approach producing heavy rain and lightning, lured perhaps by the fact the previous airplanes had landed without incident. They could have made better use of their airborne radar to realize the weather picture was changing. Their company procedures advocated the TO/GA mode of their flight director that was not optimized for a windshear escape. The pilot pushed the nose over once the stick shaker activated. Their initial ground contact indicates they might have survived had the pilot simply kept the pitch positive after the stick shaker activated. Present day pilots need to understand their aircraft's windshear escape procedures and if those simply state TO/GA, they need to understand the limitations of that mode.

What follows are quotes from the relevant regulatory documents, listed below, as well as my comments in blue.


Accident Report


Narrative

[NTSB AAR 86-05, ¶1.1]


Analysis

[NTSB AAR 86-05, ¶1.7]

[NTSB AAR 86-05, ¶1.10.1]

[NTSB AAR 86-05, ¶2.4]


Probable Cause

[NTSB AAR 86-05, ¶2.4] The National Transportation Safety Board determines that the probable causes of the accident were the flightcrew’s decision to initiate and continue the approach into a cumulonimbus cloud which they observed to contain visible 1ightning; the lack of specific guidelines, procedures, and training for avoiding and escaping from low-altitude windshear; and the lack of definitive, real-time windshear hazard information. This resulted in the aircraft’s encounter at low altitude with a microburst-induced, severe windshear from a rapidly developing thunderstorm located on the final approach course.


See Also

Abnormal Procedures / Windshear

Radar / Techniques


References

NTSB Aircraft Accident Report, AAR-86/05, Delta Air lines, Inc., Lockheed L-1011-385-1, N726DA, Dallas/Fort Worth International Airport, Texas, August 2, 1985