My memories are fading here, but the hotter landings might be related to the issue of a steep nose-up attitude causing the wings to block air to the tail and causing a stall of the high-mounted vertical stabilizer. This caused at least one landing accident early in the 727's service. The fix was to increase landing speed. Does anyone remember this? Can't find a reference to it ...

(Written on 14/08/2020)(Permalink)

Good point, microwalda. This is especially true in safety-critical systems. When a system meets its requirements and is well seasoned, leave it alone.

(Written on 14/08/2020)(Permalink)

Great example of Mr. Huls' point above. My Dad flew Mustangs with Bob in the fifties. Bob was a true pilot's pilot. But even airmen of Bob Hoover's calibre and experience can make a mistake.

(Written on 24/07/2020)(Permalink)

w2bsa, Stephen, and Thomas: I call. I have a similar 40 year background in software engineering, with the last 25 years spent in safety-significant software systems for medical devices. All of your general comments on software design are correct -- software of any complexity will have faults and defects. What alarms me (pun intended) is that, in the FINAL verification and validation phase of this software development, Boeing is still finding defects in the avionics software that have the HIGHEST risk severity possible: loss of the aircraft. In my experience, finding such new show-stopping high-risk defects at this late stage of development is a huge red flag that indicates 1) the software architecture is flawed in its ability to detect, contain, and mitigate high-risk failures ("exception handling"), and 2) the software development PROCESS employed was itself flawed in its ability to find and mitigate to safe levels these high-risk defects("defect containment") during review, ins

(Written on 11/04/2020)(Permalink)

Yes, the fact that he claims he didn't want to hurt anyone is a factor, but it is heavily outweighed by the potential severe harm his actions could have caused. And revenge would be a factor if some of the pilots and frequent fliers in this forum (who might take his actions as a personal threat) got ahold of this mechanic and beat him to death. So yes, let's keep him safely locked up and subject him to the full weight of the criminal justice system, which is quite capable of differentiating vindictive revenge from the protection of society (you and me) from the potential harm of this man's actions.

(Written on 13/09/2019)(Permalink)

Thank you, Kimberly. A voice of reason ...

(Written on 10/08/2019)(Permalink)

A root cause of the cargo door failures was the "straight-through" cargo doorway design in the DC-10 airframe, rather than the industry-standard tapered "plug" doorway. The plug design makes door failure very difficult, if not impossible, when the hold is pressurized. The straight-through doorway saved airframe weight and cost, but it removed a basic safety mitigation (the "plug"), leaving only the latch mechanism as the sole safety design mitigation. As Ken points out, the latch mechanism had several design flaws, including slack and bendable members, allowing baggage handlers to force the handle until they got the "green" fully-closed indication in the indicator window, while the latch pins were not actually all the way seated in the door frame. When pressurized during climbout, the inadequately seated pins failed and nothing stopped the door from blowing out.

(Written on 09/08/2019)(Permalink)

I have a 1991 Bantam Air & Space Series reprint of the (c)1963 "The Electra Story". I think you're right about the Max recovering, assuming that the multiple root causes of the two accidents are all fixed. Chapter 4 of "The Electra Story" is titled "If Another One Goes Down ...". It is an apt comment for the current situation, as Jamar Jackson noted below.

(Written on 10/05/2019)(Permalink)

Thanks, Ed. "The Electra Story" was one of my sources. I still have my old paperback. Just saw it is available as a Kindle book on Amazon.

(Written on 10/05/2019)(Permalink)

I was wrong about "grounding". The Electra was put under operational restrictions, including a speed restriction. It was not grounded.

(Written on 10/05/2019)(Permalink)