Design shortcuts meant to make a new plane seem like an old, familiar one are to blame
By Gregory Travis
In the wake of a near-disastrous cabin blowout in an Alaska Airlines 737 Max 9 on 5 Jan.—which has propelled the embattled redesign of the once iconic 737 back into the headlines—Boeing, the plane’s designer, has been shaken anew. As the Financial Times reported on 31 Jan., the company’s chief executive Dave Calhoun wrote in a note to employees that outsourcing in the 737 Max design probably went “too far.”
“We caused the problem, and we understand that,” Calhoun said. “Whatever conclusions are reached, Boeing is accountable for what happened. … We simply must be better.” Which perhaps explains why the company even declined to report their financial outlook for the remainder of 2024.
In response to the company’s near-crisis state, The Los Angeles Times reported on 30 Jan. that a former Boeing manager has publicly stated his aversion to ever flying on the redesigned 737. “I would absolutely not fly a Max airplance,” former Boeing senior manager Ed Pierson told the paper. “I’ve worked in the factory where they were built, and I saw the pressure employees were under to rush the planes out the door. I tried to get them to shut down before the first crash.”
As Gregory Travis chronicles below from a 2019 perspective, a latter-day crisis of faith about the “Max” appears to be building even more in size and stature. On 1 Feb., Reuters reported that demand for older 737 jetliners has skyrocketed since 2024’s near-disaster. As Travis describes it, the original, classic craft with “smallish engines and relatively simple systems” is, even in its advanced age, proving very tough to top.
Original article from 18 Apr. 2019 follows:
The views expressed here are solely those of the author and do not represent positions of IEEE Spectrum or the IEEE.
I have been a pilot for 30 years, a software developer for more than 40. I have written extensively about both aviation and software engineering. Now it’s time for me to write about both together.
The Boeing 737 Max has been in the news because of two crashes, practically back to back and involving brand new airplanes. In an industry that relies more than anything on the appearance of total control, total safety, these two crashes pose as close to an existential risk as you can get. Though airliner passenger death rates have fallen over the decades, that achievement is no reason for complacency.
The 737 first appeared in 1967, when I was 3 years old. Back then it was a smallish aircraft with smallish engines and relatively simple systems. Airlines ( especially Southwest) loved it because of its simplicity, reliability, and flexibility. Not to mention the fact that it could be flown by a two-person cockpit crew—as opposed to the three or four of previous airliners—which made it a significant cost saver. Over the years, market and technological forces pushed the 737 into ever-larger versions with increasing electronic and mechanical complexity. This is not, by any means, unique to the 737. Airliners constitute enormous capital investments both for the industries that make them and the customers who buy them, and they all go through a similar growth process.
Most of those market and technical forces are on the side of economics, not safety. They work as allies to relentlessly drive down what the industry calls “ seat-mile costs“—the cost of flying a seat from one point to another.
Much had to do with the engines themselves. The principle of Carnot efficiency dictates that the larger and hotter you can make any heat engine, the more efficient it becomes. That’s as true for jet engines as it is for chainsaw engines.
It’s as simple as that. The most effective way to make an engine use less fuel per unit of power produced is to make it larger. That’s why the Lycoming O-360 engine in my Cessna has pistons the size of dinner plates. That’s why marine diesel engines stand three stories tall. And that’s why Boeing wanted to put the huge CFM International LEAP engine in its latest version of the 737.
There was just one little problem: The original 737 had (by today’s standards) tiny little engines, which easily cleared the ground beneath the wings. As the 737 grew and was fitted with bigger engines, the clearance between the engines and the ground started to get a little…um, tight.
For full article, click the link above.