Noise Abatement and Operational Constraints at John Wayne Airport (SNA)

At John Wayne Airport (SNA) in Orange County, California, noise abatement on departures is managed through a combination of specialized Noise Abatement Departure Procedures (NADPs), strict regulatory limits, and operational constraints. Because SNA is located in a densely populated, noise-sensitive residential area, the airport enforces… Read more

New Glenn Failure, May 28, 2026

Tough day for Blue Origin’s New Glenn. Blue Origin was performing a static fire (hotfire) test ahead of an anticipated fourth launch — the rocket was likely fully fueled, contributing to what is described as one of the largest rocket explosions in U.S. history. Blue Origin,… Read more

Shock, Vibration, Fatigue & Machinery Classes Beginning September 2026

This September 2026 course series provides practical training in shock, vibration, fatigue, structural dynamics, FEA, machinery vibration, acoustics, and rotor dynamics for engineers working with test data, qualification requirements, failure analysis, and mechanical system reliability. Each one-hour class is organized in a semester-style format, with… Read more

Effective Modal Mass and Modal Participation Factors

ModalMass_revK.pdf Effective modal mass and modal participation factors provide a quantitative basis for identifying dynamically significant vibration modes and for guiding modal truncation in structural dynamic analyses. This paper presents a unified formulation for both base-excited systems and grounded systems subjected to externally applied forces.… Read more

Fatigue Cracks in Anodized Coatings

Image reference: https://onlinelibrary.wiley.com/doi/full/10.1002/adem.202300394 What Is Anodizing? Anodizing is widely used to improve corrosion resistance and surface durability in aluminum and other light metals. However, under cyclic loading, anodized coatings can play a surprising, and sometimes detrimental, role in fatigue performance. This post walks through why… Read more

Dithering Vibration

Figure 1. Space Shuttle Orbiter Ku-band Antenna Introduction Mechanical vibration is usually undesirable in a structure because it can lead to fatigue and other types of failures.  Vibration does have its beneficial uses, however.  For example, dither vibration was used to ensure that the Space… Read more