Vibrations and the glass cockpit

Tom-D

Tom-D

Taxi to Parking
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Tom-D
We all know that the 6 cylinder runs smother than the 4, So do you believe the vibration difference will have any effect on the longevity of these very expensive instruments?
 
Tom-D said:
We all know that the 6 cylinder runs smother than the 4, So do you believe the vibration difference will have any effect on the longevity of these very expensive instruments?
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No. They last just fine in helicopters which can be far from smooth in some conditions. Now reduced life on aircraft batteries due to the new toy effect. All day long.
 
Yes, I believe the vibration levels on some platforms can cause equipment issues. The MIL and TSO equipment can handle Shock and vibrations better. I used to design systems for Naval Frigate SH-2 Helicopters and they had a life of shock and vibration. I'd much rather have fully qualified systems.
 
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If component "A" is subjected to more vibration than component "B", then "A" will fail before "B" due to the increase in vibration if the component is in any way vulnerable to damage from vibrations. Frequency of vibration can be an even bigger factor. Aircraft radios seem to spend a lot of time in the repair shops and some of it is due to vibration. Items like solder joints can fail from heat cycles, overheating, over load, improper grounding and certainly engine vibrations. The difference between four and six cylinder engines? Probably negligible, but that that small difference has it effects, over time.
 
Brad Smith said:
The difference between four and six cylinder engines? Probably negligible, but that that small difference has it effects, over time.
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It has been proven a gyro will fail 50% faster behind a 4 cylinder engine, thus my question.
 
SkyDog58 said:
Sure. That's why I'm looking for a plane with a V12.
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Be careful what you wish for--like the Coneheads, it's all about mass consumption.

20171021_100704.jpg

You'll also need a very large cowl to enclose it . . . . . .
 
Hank S said:
You'll also need a very large cowl to enclose it . . . . . .
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Couldn’t you have at least posted a nice twin-turbo AMG built one from Mercedes?

I think I threw up a little in my mouth when I saw the Jaguar covers. LOL.
 
denverpilot said:
Couldn’t you have at least posted a nice twin-turbo AMG built one from Mercedes?
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Sure I could post a picture of those, too. But there's not one of them in the garage. Got a couple dozen AMU laying around I can use to buy one?
 
Flying behind a Jaguar engine? Better install a BRS at the same time you install the engine.
 
Hank S said:
Sure I could post a picture of those, too. But there's not one of them in the garage. Got a couple dozen AMU laying around I can use to buy one?
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Heheheh. I’ve been half heartedly looking for one. An older one.

I don’t need the diesel truck and I’m also an automotive idiot, so maintaining an old AMG Benz sounds just perfect for me. LOL. At least I’m a notch above BMW on the pain scale, that way. And a number of notches above Jag. ;) ;) ;)

Need to get serious about selling the truck first, though. And you don’t need quite that much money for the older ones.

They sound sooooo nice, audio wise that is. AMG did a nice job on their exhaust. Quiet and unassuming until you romp on them, then this wonderful sound comes out of a four door sedan that looks like grandpa should be driving someone around in it in the back seat, reading a WSJ. LOL.

Plus, zero to 60 in just under four seconds out of a four door sedan and over 500 HP? Such fun to be had entering on ramps... and then set the cruise at the speed limit and watch the other drivers get totally annoyed at grandpa in his luxury sedan. Hahaha.

I envision driving shenanigans in my future. :) And no, I don’t care that they get 8 MPG in the city. :)
 
Most modern electronics designed for rough environments are tested on a “shake and bake” machine, by the way.

Simulates years of expected vibration in months, as well as thermal cycles. Common failure points are found and corrected.

They’re neat machines. We tested telecom gear in them, and we weren’t really even expecting any vibration at all in the typical telecom environments other than during shipping, and we could control the G-forces imparted to components on boards by having g-shock warning stickers inside the packaging.

Hint: Never put g-shock devices on the outside of shipping boxes. The UPS and Fedex truck drivers will just hit them hard enough to set them off, for fun.

We did expect thermal cycling.

We took both the shaking and the baking (and freezing, the machines can do that too) to extremes well beyond what we rated the gear to operate at. It was a very severe test.

Always knew when a new product or board rev to fix something in hardware was being released. All the shake and bake machines except for one kept available for real time testing, were all running with their front doors locked and making various noises depending on what they were doing at the time, out on the manufacturing work floor.

I’m sure part of certification requires some level of shake and bake.
 
I always contracted out the testing, which included dropping onto various faces and corners. Then we did the inspection of contents. FedEx / UPS out and back was just a bonus!
 
Given that aircraft have had electronics in them for decades its reasonable to assume we might be able to build more complex systems and have them be as durable.

FWIW, Garmin just announced the G600H, a new helicopter autopilot. Can't wait to see the pricing on them lol.

https://buy.garmin.com/en-US/US/p/625023
 
Tom-D said:
It has been proven a gyro will fail 50% faster behind a 4 cylinder engine, thus my question.
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Would you have a link to any info on that? Sounds like interesting reading.

Regarding the question, while I haven't taken modern avionics apart, I'm betting they're all surface mount components which are less massive and due to their use and nature muss less susceptible to vibration. I just can't see it as making any difference.
 
I was once employed at a manufacturer of refrigeration units for aircraft that would send out the prototype units off-site for testing. This included mounting the units on a centrifuge for "G" testing. The ones destined for the military had much higher G loading than the civilian units to prove their reliability for operation in a much harsher environment. All units would then undergo vibration, climate and salt spray tests. Production units were operated on test stands and checked for operational performance, leaks etc. before shipping. You wouldn't believe how many units were returned rather quickly after shipment for failure. All mechanical devices are prone to failure even when put through rigorous testing. The fact that an item is FAA/PMA certified and cost a bundle doesn't mean much when it fails in the clouds or over the Rockies. You pays your money and takes your chances.
 
bnt83 said:
Given that aircraft have had electronics in them for decades its reasonable to assume we might be able to build more complex systems and have them be as durable.

FWIW, Garmin just announced the G600H, a new helicopter autopilot. Can't wait to see the pricing on them lol.

https://buy.garmin.com/en-US/US/p/625023
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That’s a nice AP. I’d be willing to bet it’s a bit more expensive than the 20 grand 600 version for airplanes. We’ve got a COBHAM in ours and it lists for 125 grand. I heard we got a discount for buying in bulk though.

https://www.cobham.com/media/153226/helisas_brochure 2009.pdf
 
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