Classic Aero Design Rear Headrest

Has anyone fitted the Classic Aero Design rear headrest?

If so would appreciate any photos and recommendations for the mounting of the headrest to the top skin. Still awaiting a reply from CAD as no instructions given - only the brackets.

Regards

Bob Ellis
Fuselage drilled and about to be all taken to bits!
www.rv-8.co.uk

Sent it back....

I thought the design was way too big and clumsy. I sent it back and had them cut it down to about a third its original size and used some 3M dual loc to stick it on the rim of the fuselage in the apprpriate place.

Will post a pic later-gotta go take one.....

Looks nice and is not in the way.

My wife at least thinks I did something for her comfort, mainly I think it looks cool.

CAD Headrest

Thanks Chuck for the quick reply.

Funny how we view things in different ways as I thought the size was OK.

For those who have not seen it please see the second photo in my log link

It should not really restrict vision, unless you got the neck of an owl or an F-16 fighter pilot. I'm purely fitting it for insurance as the RV's offer no whiplash protection in an accident.

My front headrest will also double up as an EFIS repeater and, non-negotiable from the co-funder of this project, a DVD/MMC player!

Regards

Bob

Bob Ellis said:

I'm purely fitting it for insurance as the RV's offer no whiplash protection in an accident.

Click to expand...

Whiplash is caused when your neck is snapped backward. There is very little chance of whiplash in an airplane unless you plan to stall and tail-slide into the ground. Not too many "rear end" collisions in airplanes.

CAD Headrest

Mel

Engine starts running rough .. your heartbeat increases ... engine stops and all goes quiet ... look for a field to land in ... found one .. touch down but field is shorter than you thought and there is a ditch at the end ... thud you rapidly come to a halt = whiplash.

Engine fails after take off ... no time to chose a field . you're stuck with the one ahead .. again too short and you hit the hedge at the far end at 30 kts = whiplash

How many RV's (including tail draggers) have nosed over?

Whiplash is not just for auto mobiles.

Bob

All of the scenarios you are describing are sudden decelerations, which result in hyperflexion injuries and would not be prevented by a restraint behind the head. "Whiplash" as commonly used generally means hyperextension of the neck resulting from a sudden acceleration of the body (e.g., someone hitting your car's rear end), with the head lagging behind. That sort of injury *is* mitigated by a headrest, which is why they are now required in automobiles.

However, as Mel says, that mechanism of injury is unlikely to occur in an aircraft unless someone runs into your tail at the hold short line.

-- Chris

When I was young (and before high-back seats) I received whip lash injuries when the car ran into a ditch. "For every action there is a re-action". I got the whip-lash from the re-action.

CAD Headrest

Chris

I agree that car headrests primarily protect from rear ends but I also agree with RetiredRacer, whose point and mine is demonstrated in this video. If it were not for the headrest the head would have been whipped right back, just like it would in an RV.

So not only should we pad our instrument panel I firmly believe that a headrest may help as well.

Bob

Actually, this sort of injury is a result of Newton's First Law rather than the Third Law. Because your body is restrained by your harness, it decelerates with the seat (which presumably remains attached to the frame of the vehicle), whereas your unrestrained head tends to continue moving in the same direction and at the same speed as the vehicle until the structures of your neck begin to provide resistance to bring it to a stop.

What is interesting about recent high speed imagery of rear-end collisions is that the cervical spine experiences both hyperextension (in the lower vertebrae) and hyperextension (in the upper vertebrae), which probably causes the soft tissue damage that causes the pain and injury associated with whiplash.

Again, whiplash is acceleration injury, not deceleration injury. (You can actually suffer a whiplash injury from a collision with a barrier in front of you AS A RESULT OF A HEADREST: after the initial forward motion of your head, you may "bounce back" and hit the headrest hard enough (about a 10G impact) to produce a secondary deceleration injury (and whiplash).

The best method to prevent such injuries is the neck restraint worn by race car drivers. However, few pax and even fewer pilots are likely to adopt their use. ;-)

-- Chris

Bob Ellis said:

So not only should we pad our instrument panel I firmly believe that a headrest may help as well.

Click to expand...

I read an article somewhere that reported a significant improvement in survival due to padded glareshields in certain aircraft. No idea where I read it, however, so I can't provide a reference, unfortunately.

That's happening more often these days, it seems.

-- Chris

Whiplash aka Cervical Acceleration-Deceleration Syndrome

The best science on whiplash comes from Art Croft's group in San Diego. He calls it "Cervical Acceleration-Deceleration Syndrome". The high speed video they have on low speed impacts is amazing to see... The neck gets injured (think "sprung") in both flexion and extension as well as in compression. Interestingly, whiplash injuries appear to actually be worse at lower speeds. You can get easily get 15 gees on your head with a 10 MPH impact, all this known by the Spine Research Institute of San Diego instrumenting real people in real staged crashes.

I just donated half my day to work on nurses at our local hospital, and again I was reminded just how bad people's necks are. We are in the midst of a whiplash pandemic.

It affects much more than your neck... Your nervous system can get stuck in "fight or flight" so you run more adrenaline than you should 24/7... aka "Sympathetic Activation". This affects everything. Blood pressure, body-fat levels, inflammation, and so on. People will often pack on a lot of weight in the year after an untreated "whiplash" injury.

Don't mean to go on, but this is my day job!

Hans

Hans,

I completely agree -- I used to be an ER doc, then a Navy flight surgeon, so this stuff used to be part of my day job too! You're right, it's amazing how many G's are generated even by low speed impacts. And from everything I've read about whiplash, the actual mechanical injury is just the start of the problems in some folks, as you said.

-- Chris

Question for Hans and Chris

Thank you both for your posts. However, I'm unclear about the ultimate recommendation. Are you guys saying that headrests in the 8 are a good idea or ...?

Thanks,

I have them in mine. I just really like the looks. Haven't tried them in a crash yet though.

I'm not a Doctor, not do I play one on TV, but...

campi said:

Thank you both for your posts. However, I'm unclear about the ultimate recommendation. Are you guys saying that headrests in the 8 are a good idea or ...?
Thanks,

Click to expand...

Many things I've read, written by people who are supposed to know, say that a headrest will not help a forward facing person in an aircraft crash, and in some cases can actually increase the likelihood of injury.

What Mel said.

FWIW, none of the military aircraft I flew had high backed seats. At least in the Navy, the ones that do have headrests have them because of high acceleration forces (catapult launches) or because they played a role in the ejection seat system.

That said, I'll have high backed seats in my -10, but it will be for comfort (my wife naps in moving vehicles she's not driving) and because I plan on putting in a rear seat entertainment system for the kids.

-- Chris

Thanks for the clarification ...

No headrests for me!

Thanks,

High Headrests

I don't think high or low would make much of a difference in a plane. The only accident scenario where a high headrest would help would be if you smashed into something going backwards.

Hans