I recently flew as a passenger in a CRJ900 jet similar to the one shown in Figure 1. This aircraft has two GE CF34-8C5 engines, as shown in Figure 2. This engine has two high pressure axial flow stages that drive the N2 compressor, and… Read more
V1 is the critical takeoff speed for an aircraft at which the pilot must make a decision. The aircraft can still safely stop if the takeoff is aborted prior to V1. The abort could be due to an engine failure, bird strike, blown tire, etc.… Read more
Malaysia Airlines Flight 370 The leading news story the last few days has been Malaysia Airlines Flight 370 which mysteriously disappeared on March 8, 2014, somewhere over the South China Sea or perhaps the Strait of Malacca. The aircraft was a Boeing 777-200ER. The cause… Read more
N571UP, the aircraft involved, seen taking off from Dubai in November 2008 * * * A UPS Boeing 747-400 flying between Dubai International Airport and Cologne Bonn Airport crashed close to Dubai airport, killing the two crew members, on September 3, 2010. The aircraft had… Read more
Here is Matlab script for plotting the MIL-STD-810G, Figure 514.6D-2, Category 13, Propeller Aircraft Vibration Exposure PSD, including the overall GRMS level. propeller_psd_grms.m * * * See also: Bombardier Q-400 Turboprop Acoustics Aircraft Shock & Vibration – Tom Irvine
Amazon Product Link: Bose QuietComfort 3 Acoustic Noise Cancelling Headphones * * * * * * * * * * * * * * I have take several business trips lately with more to come. One of my pet peeves is hotel room noise from HVAC… Read more
A new helicopter design must undergo thorough testing to ensure the reliability of the design with respect to vibration. A new design undergoing testing may encounter severe vibration while it is on the ground, preparing for takeoff. A similar problem may occur immediately after landing. Many helicopters… Read more
I recently flew from Spokane to Seattle, Washington on an Alaska/Horizon Air Bombardier Q400 aircraft, similar to the one in the above image. This model aircraft has two Pratt & Whitney Canada PW150A turboprop engines. I captured the following video during cruise using a Motorola/Android… Read more
FAA Federal Aviation Regulations FAR-25 Appendix G, Continuous Gust Design Criteria, requires a continuous turbulent gust analysis for transport aircraft. The gust PSD function is given in: The von Karman Vertical Gust Spectrum A Matlab script for generating a continuous gust velocity PSD is given… Read more
There are many variables which affect the touchdown shock level of an aircraft. These include: Descent or sink rate Forward and side velocities Roll, pitch, and yaw angles and corresponding rates Weight and center of gravity Cross wind, wind shear, gusts, etc. Runway contact loads… Read more