Variation-selection in the innovation of the retractable airplane landing gear:

the Northrop ‘anomaly’Walter G. Vincenti

경영학과 오퍼레이션전공석사 2 학기 서동엽 / 오다 아야카

Quick Summary

In the early 1930s, airplane landing gear went through the process of technical change.

However, Northrop introduced a modified landing gear, which looks anomalous in the context of its time.

It proves a typical of the variation-selection learning process normal in engineering.

Revolution in Airplane Landing Gear (1930s)• Retractable landing gear entered prominently into airplane

design in the first half of the 1930s.

Fixed Gear Retractable Gear simple design of bars, wheels, and brakes that are not retractable into the wings or fuselage

The landing gear is attached to mo-tors which lower it before landing

reduces the risk of problems at land-ing, but it does create extra drag dur-ing flight

causes no extra drag. increases the length of flight significantly

Northrop ‘Alpha’ - Initial version

Inaugurated the series in 1930. Featured stressed-skin all-metal

construction. Channel-shaped aluminum wing FIXED landing gear

“A retractile gear is being designed to be incorporated later.” (1929) -Jack Northrop

New Northrop ‘Alpha’

“Pants” type gear

왜 Northrop 은 retractable landing gear 를 채택하지 않았나 ?Northrop 의 선택이 옳았다고 생각하는가 ?

Northrop Following the XFT-1, Northrop began apparently to see the

trade-offs differently. As speeds continued to climb, the need to reduce drag became

dominant. Gradually went over to the retractable gear.

Northrop Grumman ‘B-2 Spirit ‘

결국 retractable landing gear 를 선택하지 않았나 ? 아직도 선택이 옳다고 생각하는가 ?

‘Unforesigtedness’

Northrop’s trouser gear served as a variant.

What is the take-away from the blind person’s story?

What is Variation-Selection Model?

Dominant Design

Design 1

Design 2

Design 4

Design 3

Design 7

Design 5

Design 6

Theory vs Practice Theory has a limited role in guiding practice. Practice serves indispensably to appraise (or to reshape) theory.

Science 과 기술의 변화

Dosi (1982) defined “technological paradigm” as “model” and a “pattern” of

solution of selected technological problems,

based on selected principles derived from natural

sciences and on selected material technologies.

Heuristics?

Scientific realism vs RelativismRealism or Relativism for Technical change theory?

External World

Scientific Evaluation and testing

Genuine knowledge

Scientific Realism’s view of Reality

Uninterpreted Reality

Public ConstructionOf Reality

Scientist’s worldview

Research Paradigm

Mental Interpretationof Reality

Relativistic view of Reality

Critique / Further Research Suggestions

Because this article was more like a case study, it is difficult to criticize any shortcomings. I think it would be interesting if we look at other cases where we can see the variation-selection learning process. Also it may be interesting to look at how the environment changed after the technical change in the landing gear occurred, like the study done by Tushman and Anderson (1986).

The major difference between scientific realism and relativistic view is in the nature of scientific reality. I personally think the author’s view is more close to ‘relativistic view’ - the concept that points of view have no absolute truth or reality, which I totally agree with him. Because the way how technology is adopted and change is more relative, subjective according to differences in perception and consideration.

Thank you ^^