Tag Archives: aviation

Fly-by-ear: The SIMONA flight simulator and the LN-3 INS

FlyByMax presents two terrific videos on how real and perceived forces play into flight simulator and inertial guidance systems.  Simulators don’t just mimic the motions of their vehicles.  Designers have to use the human vestibular and visual systems to mix the physical movements and scene projections to maximize realism.

Youtube Channel: FlyByMax

Exploded Views: Animagraffs on the SR-71

Jake O’Neal’s meticulously researched and lovingly rendered engineering animations are one of the highlights of modern-day Youtube.  He’s outdone himself with his recent masterpiece on the SR-71’s innards and outards.  The Blackbird is one of the last century’s artistic triumphs and has inspired admirers all over the world.  O’Neal dove deeply into the literature and pulls back the covers from beak to tailfeathers.  The section on the inlet and J58 powerplant is as accurate as the 2015 benchmark from “Tech Adams.”

O’Neal goes beyond the “glamorous bits.”  Pay close attention to the “mixer” that translated pilot stick inputs into precise actuator motions to control a plane flying at Mach 3+.  I’ve been following the Blackbird family for decades and I never knew about this.

On top of that, he has just released a behind-the-scenes film on how he created the model and animations using the free Blender program.

Youtube Channel: Animagraffs

LAX Maintenance: Stig Aviation

SpeedbirdHD has dramatically cut back on his insider views of LAXStig Aviation is a new channel that fills that gap.  SpeedbirdHD focused on insane closeups of takeoffs and landings thanks to his unparalleled access.  Stig is a maintenance technician for a major airline who documents interesting aspects of the job through sixteen hour shifts which he nevertheless enjoys.  Tires, engines, cockpits, or fluids, he’s got the scoop.  He optimizes for mobile phones so the videos are all in portrait mode but other than that, there’s a lot of good stuff for the aviation curious.

Youtube Channel: Stig Aviation


Tristar Trifecta: The L-1011 and its troublesome engine

The L-1011 has mostly disappeared from the airways but is enjoying a burst of nostalgic appreciation.  Here are some history lessons and some technology lessons, at multiple levels of detail.

Youtube Channel: Mustard

Youtube Channel: The British Library

Youtube Channel: AgentJayZ

LAX planespotting from and on a different level – SpeedbirdHD

The small and very active community of aircraft photographers and videographers is putting up some superb material on the usual outlets. Close to home, many shoot from El Segundo’s Clutter Park where they can get nice views of LAX’s south runway operations although with some interference from low buildings.

Then, there is Youtube’s SpeedbirdHD. He says little about himself other than that he is an aviation enthusiast in Los Angeles. There must be more to it than that. He has unique access to LAX operations, almost assuredly through a job on the premises. His videos of the heavy metal flying in and out are in a league of their own. Speedbird and his HD camera get tarmac footage of regional jets, superjumbos, and even the occasional miltary lifter from every runway. His edits usually include relevant air-traffic control conversations in the background. Top class stuff.

Here’s his channel. His 2012 highlight reel is a good place to start.


Real-time LAX air traffic tool – a must-have for South Bay residents

Instrumentation makers Bruel and Kjaer are working with many airports to measure and display sound levels in the neighborhoods they adjoin.   B&K’s Webtrak tool for LAX is available at http://ems02.bksv.com/webtrak/lax4

See flights coming in and out of the greater Los Angeles area in real time.  See sound levels in Playa del Rey, Hawthorne, El Segundo, and Inglewood.  There’s also a replay feature.  Use Historical Mode to pick a day and time and see what happened; speed it up if you like.  If you’d like to complain about a particular flight, select the icon of the suspected flight, get its number, and click a link to file a report.

The Beach Cities are usually  quiet despite LAX but there are many nights where the engine roar is powerful despite  distance and intervening structures.  So, what can cause this?  Thermal inversion layers in the atmosphere are known to refract sound waves due to the index of refraction difference at the boundary.   Acoustical engineer  Mike O’Connor offers a nice summary of the physics, analogous to optical refraction, at http://www.mocpa.com/inversion.html

He concludes
“It is not only noise from vehicular traffic on distant segments of roadways that is boosted in strength by temperature inversions. Emissions from distant trains and commercial aircraft (during takeoffs) are also amplified. The reader who has never before taken note of this phenomenon might now try to see if it’s ‘real’. Just listen to the background noises from distant trains, distant aircraft (just during takeoff runs) and vehicles on distant roadway segments, preferably after dark or shortly before or after dawn, and note the atmospheric conditions. Disregard windy conditions, but take note of the loudness of such noises under all other atmospheric conditions. It should become apparent that the noise levels from distant sources are clearly higher on some days than on others, even though the observations were made at approximately the same time each day. With some effort it should also be apparent that the calm and clear conditions that are said here to give rise to temperature inversions are in effect when the distant sources seem loudest.”

Henry Robinson offers a more detailed treatment at http://www.lochlyn.org/atmophys/sound/sound.pdf with an interesting observation about amphitheatre design.

“On a day when convection near the ground causes the temperature to decrease rapidly with height, sound heard on the ground from a departing aircraft will be muffled because the sound rays, and energy, will be forcing the sound upward. Indeed, balloonists often can hear conversations of people on the ground but be unable to make themselves heard by the same people on the ground. The Greeks constructed their theaters, as in Figure 3, so everyone could see, but, in doing so, they also used the natural curvature of sound to enable everyone to hear as well in afternoon plays.

Takeoff during well mixed conditions is relatively quiet at the ground but takeoff through an inversion concentrates the sound under the aircraft.  Observe sound abatement procedures while taking off in an inversion situation.”

So, is that the mechanism at work on noisy Redondo Beach nights?  This is  worth some observation and checking against weather data.