Archives For Video

What is shimmy?

It is an unstable lateral/yaw oscillation in a landing gear. This NASA video shows shimmy testing at Langley, and in it, you can see the lateral movement and twisting modes developing.

Here’s what one presentation describes:

“Among the various components that make up an aircraft, the landing gear is an important and complex system. A recent study indicates that the landing gear continues to be the most failure prone system of Western-built commercial jet transports [11]. According to this study there were 1408 system related accidents between 1958 and 1993 in total; about one third (456) of these accidents were related to landing gears. This is more than twice as many as the next most failure prone category engines, which accounted for 192 accidents. Apparently the landing gear design and maintenance procedures may still require improvements to enhance flight safety.” (Shimmy of Aircraft Main Landing Gears (pdf))

References and Bibliography on Landing Gear Design

Video of Landing Gear Drop Test by Goodrich

Airbus Shimmy Research and presentation

LMS Engineering Services Web presentation and video on Landing Gear Shimmy

Early Landing Gear and Wheel Testing (video)

Video exponentially improves our ability to use picture to communicate 10,000 words, and this is not only one of the fundamental ATOMs but also an elementary and critical element in the strategy to inform and invest. These are just a few of the reasons videos consistently make it to these posts.

Flight Test on YouTube is a bit like Alice in Wonderland — once you go down the rabbit hole, you may not come back out. Here are some fantastic resources and some YouTube channels from FTOs.

NASA’s historic register

GE Aviation

Here’s a sampling of others (with an admitted but unintentional European theme).
Snecma Safran Group

Thales

Dassault Aviation

Airbus

Lockheed Martin shares Edwards AFB

Flight Test organizations generally fall into four broad categories, and I tried to pick a video from each:

  1. Professional Societies
  2. Aerospace Industry and Manufacturing
  3. Research and Development organizations
  4. Test Pilot Schools and university programs

For the fastest way to connect, check out these lists also: Flight Test on Facebook and Twitter.

This new column will feature a brief description, photo or video, and/or reference that talks about a Flight Test Technique that students at USAF Test Pilot School are currently learning. It’s an alphabetical list of FTTs together with a chronological account of what future test pilots and flight test engineers are doing right now. It will complement the previous Friday’s FTT tweets as well.

taws_2What is an FTT? It is the fundamental maneuver building block used by flight test engineers and experimental test pilots.

If you are wondering “what is a systems FTT?” then start here.

Examples of systems flight test on civil aircraft include TAWS–terrain avoidance and warning system.

Terrain awareness and avoidance are one of the hottest areas of system flight test, research and development.

TAWS (terrain avoidance warning system)–a terrain database integrated with an aircraft navigation system and multi-function displays.

@NASADryden and @LockheedMartin have been been flight testing Automatic Collision Avoidance Technology integrated with the aircraft flight control system/autopilot on an F-16 flying test bed at Edwards AFB. Click here for the NASA website, photos, and videos about the project.

3 Videos
NASA’s Automatic Ground Collision Avoidance System from @AvWeekGuy:
1. Overview: Training and Flying NASA’s ACAT Flying Test Bed

2. F-16 low level from Lake Owens to Sierra Nevada Mountains

3. Synthetic Vision Systems (SVS) are also designed to increase terrain awareness:  @GulfstreamAero /Honeywell SVS Flight Test

Previous: Doublets and Singlets

 

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This post summarizes references and #FTT tweets from the previous Friday. What is #FTT Friday?

#FTT Friday
Each Friday, @FlightTestFact will deliver examples, definitions, and explanations of flight test techniques for the entire day. You can view these tweets by searching for #FTT and #flighttest as depicted below. You can also click on the picture below to be taken to the twitter search results. What FTT would you like to know more about?


For more information, you can read the post What is an FTT? or check out the alphabetical index or the FTT blog category for several examples, test cards, and videos of FTTs.

This new column will feature a brief description, photo or video, and/or reference that talks about a Flight Test Technique that students at USAF Test Pilot School are currently learning. It’s an alphabetical list of FTTs together with a chronological account of what future test pilots and flight test engineers are doing right now. It will complement the previous Friday’s FTT tweets as well.

What is a doublet?
1. An elementary open loop maneuever performed in a single axis of motion.

2. A flight control input used in flying qualities flight test to excite an aircraft mode of motion. Here is a video of a Bonanza doing a rudder doublet to excite the lateral directional modes of motion.

3. A symmetric input in both directions–for example, you could push the stick forward one inch then pull the stick back (past neutral) one inch and then return to center.

What is a singlet?
An asymmetric flight control input in one direction. For example, you could push the stick forward one inch then then return to center.

Here is a time history plot of the singlet – the flight control input (elevator) is the third line, and the other lines are the aircraft response.

NASA paper - singlet time history

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This post summarizes references and #FTT tweets from the previous Friday. What is #FTT Friday?

#FTT Friday
Each Friday, @FlightTestFact will deliver examples, definitions, and explanations of flight test techniques for the entire day. You can view these tweets by searching for #FTT and #flighttest as depicted below. You can also click on the picture below to be taken to the twitter search results. What FTT would you like to know more about?


For more information, you can read the post What is an FTT? or check out the alphabetical index or the FTT blog category for several examples, test cards, and videos of FTTs.

Previous

Campus Research Airport is a joint scientific union of the research institutes of aerospace and aeronautics at TU Braunschweig, the DLR, and Leibnitz University (LU) in Hannover.

The Do-128 in this video is one of their test aircraft, as described here.

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This irregular post features the current events and connections column both here and on twitter. You can also search this website for the tags “current-events” or “connect” or link to this page of flight test organizations to access all of these posts.

Like last week’s NASA Orion introduction, here are 4 ways to learn more about airdrop flight test and the NASA Ares JDTV program, including videos, photos, and technical papers. Continue Reading…

Here are four essential links for NASA Orion and C-17 Airdrop flight testing: a video, the NASA Orion homepage, NASA Orion technical papers, and the NASA CPAS Youtube channel.

1. NASA Orion Airdrop Flight Test – First Flight Video
The first time NASA dropped the Orion CPAS, things didn’t go well, as you can see in this video.

2. NASA Orion Program homepage
You can see they bounced back and are testing successfully now at this NASA Orion link.

3. NASA Orion CPAS Technical Papers
NASA Orion CPAS Airdrop Test – Assessment of a Failure or download it from NASA’s Technical Reports Server. Read more about the whole program here: Development and testing of the ORION CEV.

4. NASA Orion CPAS on Youtube
Here is a montage of the many video angles/HD footage used in the most recent successful airdrop test of the Orion CPAS.

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Check out youtube or pinterest for more flight test videos, or follow @FlightTestFact on Twitter for more flight test pictures, videos, or references daily.

Video exponentially improves our ability to use picture to communicate 10,000 words, and this is not only one of the fundamental ATOMs but also an elementary and critical element in the strategy to inform and invest. These are just a few of the reasons that this weekly video column exists.