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From forbes.com:

In 1992, a DC 8 cargo aircraft suffered turbulence so severe over the Front Range of Colorado’s Rocky Mountains that its left outboard engine was completely ripped off as well as some 12 feet of its left wing’s leading edge. Mercifully, the pilot was able to make an emergency landing at Denver International.

If a 787 was put in the same turbulence as the DC-8, would the wings snap off? The DC-8 is from the '50s while the 787 is a new aircraft.

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    $\begingroup$ 12 feet of its left wing’s leading edge — that's not the same thing as the wing 'snapping off'. The wing was overloaded, and a portion of it was damaged and torn from the airframe, but the DC-8 in question did not lose any span. See the NTSB report: aviation-safety.net/database/record.php?id=19921209-1 $\endgroup$
    – egid
    Commented Dec 17, 2018 at 18:25
  • $\begingroup$ Still classifies as wing damage. There's a photo of BOAC Flight 911 where the wing folded before the plane crashed (also due to turbulence) taken from a person on the ground who was filming the plane flying over Mt. Fuji. $\endgroup$
    – Willy A
    Commented Dec 17, 2018 at 18:30
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    $\begingroup$ Damage, sure. You are specifically asking if wings would "be snapped off", though. If you're actually asking if the 787 would suffer the same damage as the DC-8, you need to rephrase your question. $\endgroup$
    – egid
    Commented Dec 18, 2018 at 5:24
  • $\begingroup$ @egid I read the question as "would a modern aircraft be doomed by turbulence that an old aircraft survived (just)" $\endgroup$
    – Martin Bonner supports Monica
    Commented Dec 18, 2018 at 12:17

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It's very likely that the 787 would have less problems with turbulence than the DC-8 did.

The wings of the Boeing 787 are more flexible than the DC-8, and that flexibility will damp the immediate impact of turbulence. More important, the Boeing 787 has a gust alleviation system that reacts to turbulence by counteracting the induced accelerations using the control surfaces.

Note that the aircraft certification standards have changed a lot since the DC-8 was certified. Originally the focus was very much on the maximum g-forces the wing could sustain, but this is not a very good measure for turbulence. The g-forces encountered in turbulence are the result of a combination of the turbulence itself and the aero-elastic response of the aircraft. Using a more flexible wing and gust alleviation systems will result in a much smoother ride (less g-forces) than a traditional very rigid wing.

Currently the certification standards define, in addition to a required g-force, the characteristics of the turbulence that the aircraft has to sustain. For example, see the FAA's regulation for large aircraft, FAR Part 25, Sec 25.341. This takes into account a range of characteristics of turbulence that can be encountered as well as the dynamic response of the aircraft to that turbulence.

Apart for aerodynamic and structural differences between the DC-8 and the Boeing 787, better understanding of (mountain wave) turbulence, better weather prediction, better reporting of turbulence by aircrew (simply because there are more flights) and better weather radars on aircraft have reduced the risks of encountering turbulence since the DC-8 era.

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