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Stupid Questions about Naval Aviation (Part 3)

MIDNJAC

is clara ship
pilot
So my understanding is turbulence can vibrate the plane and wreak havoc on the spine of the pilot over time. My question is, why don't they put some kind of shock absorbers in the seats? Like how you have hard seat mountain bikes (no suspension) and soft seat ones where there is a suspension/shock absorber system, why not have something that could do the same for pilots? Or would such a system just be far too difficult from an engineering perspective?

You're really doing it wrong if turbulence is a big enough part of your life to cause back problems. I don't think that is real
 

Brett327

Well-Known Member
None
Super Moderator
Contributor
So my understanding is turbulence can vibrate the plane and wreak havoc on the spine of the pilot over time. My question is, why don't they put some kind of shock absorbers in the seats? Like how you have hard seat mountain bikes (no suspension) and soft seat ones where there is a suspension/shock absorber system, why not have something that could do the same for pilots? Or would such a system just be far too difficult from an engineering perspective?
Your understanding is wrong.
 

JTS11

Well-Known Member
pilot
Contributor
So my understanding is turbulence can vibrate the plane and wreak havoc on the spine of the pilot over time. My question is, why don't they put some kind of shock absorbers in the seats?
Not sure where you're getting that understanding from. Never heard about turbulence wreaking havoc on spines

Others can chime in, but my airframe had stroking seats to absorb some of the force from a "hard landing", same for pax seats in the cabin. I'm guessing -60's have similar seats (could be wrong). But yeah, there aren't any springy seats to counter turbulence. ?
 

Random8145

Registered User
So I got hammered a bit in the Bulging Disc thread when I asked how does aviation wreck the spine (LINK) and one of the things mentioned was bad weather and vibration. I must have in my memory mixed that up as turbulence. But for the issues of bad weather and vibration, I would think a seat with shock absorption would help.
 

insanebikerboy

Internet killed the television star
pilot
None
Contributor
So I got hammered a bit in the Bulging Disc thread when I asked how does aviation wreck the spine (LINK) and one of the things mentioned was bad weather and vibration. I must have in my memory mixed that up as turbulence. But for the issues of bad weather and vibration, I would think a seat with shock absorption would help.
You’re not incorrect that vibration can be harmful, you’re just looking at the wrong type. Turbulence is not a constant during flight, and some flights don’t feel it whatsoever. The short duration and intensity isn’t enough to cause problems.

What you’re referring to is the term is ‘whole body vibrations’. While it is true that every aircraft has a bit of a vibrating tendency, it’s much more prevalent in rotary wing aircraft.

If you do some googling you’ll find quite a bit about what those kinds of vibrations can do to a back, neck, etc.

As to your question about shock absorption, historically military aircraft had ergonomics as an afterthought. The designs were more about enabling the pilot to max perform the aircraft. Examples are a reclined seat in fighters, which gives the pilot more G tolerance, or a titanium seat in a helo to keep the pilot safe from ground arms.

Shock absorption in a rotary wing aircraft typically is for mishap survival and not physical longevity. Shock absorption in fixed wing really isn’t a thing outside of landing gear struts.

I’m not an engineer so I don’t know if designing seats to combat that vibration problem is feasible. I imagine with enough money and time it would be solvable. Right now though, it’s not something that (as far as I know) is being incorporated into military aircraft design.
 
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jmcquate

Well-Known Member
Contributor
On every H-60 I see on the ground, or flying, the horizontal stab always seems to be just hanging in the down position. Does it provide pitch authority or is it just hanging there?
 

Meyerkord

Well-Known Member
pilot
On every H-60 I see on the ground, or flying, the horizontal stab always seems to be just hanging in the down position. Does it provide pitch authority or is it just hanging there?
It automatically programs (at least in the R) based off your airspeed. At low airspeeds, it automatically programs down because as you slow, there is an increased amount of rotor downwash on the stab. If it were to stay horizontal in that case, you get a more nose-up attitude which restricts visibility at critical parts of flight e.g. landing (especially on the back of a CRUDES).

Similarly, the stab becomes more horizontal as your airspeed increases. If if stayed in the down position, the amount of lift it generates at high airspeeds can actually cause uncontrollable nose-down attitudes that can lawn-dart you straight into the ground. Each stab position has it's own airspeed limit, and we have an emergency procedure that we execute in case the automatic mode fails (we have the ability to manually slew it).
 
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ChuckMK23

FERS and TSP contributor!
pilot
No stab required :)

429861402_10161420613384583_3874258161081685936_n.jpg
 

VMO4

Well-Known Member
No stab required :)

429861402_10161420613384583_3874258161081685936_n.jpg
Since this is the stupid question thread, my hangar neighbor, and owner of a beautiful Ercoupe, is a former frog driver, he said it flew faster slightly yawing, because the rear blades ate more clean air.....

....although I was a UH-1N guy, I did ride in one once, compared to the huey, it made sounds I thought not natural.
 

ChuckMK23

FERS and TSP contributor!
pilot
Since this is the stupid question thread, my hangar neighbor, and owner of a beautiful Ercoupe, is a former frog driver, he said it flew faster slightly yawing, because the rear blades ate more clean air.....

....although I was a UH-1N guy, I did ride in one once, compared to the huey, it made sounds I thought not natural.
Max performance on takeoff/climb was 15 degree right yaw.

There was a good deal of high frequency noise from transmission x2, engine output drives, oil cooler shaft and sync shaft suspended in Lord mounts.
 

insanebikerboy

Internet killed the television star
pilot
None
Contributor
On every H-60 I see on the ground, or flying, the horizontal stab always seems to be just hanging in the down position. Does it provide pitch authority or is it just hanging there?
No direct pitch authority tied to the primary flight controls. It programs automatically and it's position is based primarily on airspeed (and a few others). The intent is to keep the nose close to level on the horizon. Without the stab, the helo would get into fairly large and uncomfortable pitch attitudes based on the flight regime it was in. In a hover, it'll be full down, in forward flight it's horizontal to slightly above.
 

DanMa1156

Is it baseball season yet?
pilot
Contributor
Max performance on takeoff/climb was 15 degree right yaw.

There was a good deal of high frequency noise from transmission x2, engine output drives, oil cooler shaft and sync shaft suspended in Lord mounts.
FCFs had to be really challenging on those birds.
 
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