Passenger Loading Handles - Slider Roll Bar

I'm looking for ideas to install loading handles for the pilot and passengers on slider RV's, mainly RV7's or RV9's. Anyone have any ideas to share? I've seen some installed on the forward roll bar. My new RV7A QB kit is a slider, and this is a first for me. (slider that is)

handles

I bought those two from aircraft extras for the rollbar and they are the best
thing for getting into and out of a slider.. otherwise you or anyone getting into or out of your plane will grab the fiberglass or push up on the armrest
maybe the seatback.. but the handles are very strong if installed to plans..


Danny..

Taking a look

I'm going to take a look now... Thanks!

Handles

I've got 'em too from aircraft extras. The nice thing is they go into the roll bar and bolt on the front side, so they are fairly strong for their size. I orginally was going to run some bolts all the way through the roll bar (to hold standard drawer handles), but then you loose a lot of strength. Use them all the time now.

Perhaps welding

MCA said:

I've got 'em too from aircraft extras. The nice thing is they go into the roll bar and bolt on the front side, so they are fairly strong for their size. I orginally was going to run some bolts all the way through the roll bar (to hold standard drawer handles), but then you loose a lot of strength. Use them all the time now.

Click to expand...

The specs on this product call for a 1/4" hole in the front of the roll bar and a 5/16" hole in the rear. The roll bar is 1 1/4" OD thin wall 4130 steel and I calculate that these holes will result in a loss of 14% of the tube cross section.

In the event of a roll-over it's going to be that tube saving your bacon and it's none too beefy now....taking out 14% of it's cross section will reduce it's capacity considerably. It might be easy to fit (and I reeeeeally like the idea of having handles) but the loss of any strength in a component that could be subjected to large dynamic forces does trouble me.

A steel handle passing right through the tube and welded on both sides would be structurally better in that there would be no loss of structural capacity.

Has anyone used a welded handle.

I had two flights yesterday in a very nice RV-7A slider with two of those Aircraft Extras handles on the roll bar. They were very useful, but once I was in the aircraft I concluded that they would be a bad thing to hit your head on in a ground accident. They would do a lot more damage to your skull than just hitting the roll bar would.

Captain Avgas said:

Has anyone used a welded handle.

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Yep, all I did was go to the local weld shop and bougth something like 1.5' of hot rolled steel round bar. Brought it home, calculated the length, heated up the bend point, bent two 90's and primed. I took the roll bar and handles to a client who does exhausts. He ground the powder coat off the roll bar then welded the handles on. Total cost $3.00.

Kevin Horton said:

I had two flights yesterday in a very nice RV-7A slider with two of those Aircraft Extras handles on the roll bar. They were very useful, but once I was in the aircraft I concluded that they would be a bad thing to hit your head on in a ground accident. They would do a lot more damage to your skull than just hitting the roll bar would.

Click to expand...

Kevin,

Now that is something to consider! Having a piece of steel dowel stuck in the old noggin would probably smart just a little.

Don't need handles

Handles will weaken the roll protection unless welded. When getting out of a slider, there is a great handle already there. Just grab the roll bar brace at the top and haul yourself out. No extra weight added either!

Bruce Reynolds

14% I don't think so

Whatever you used to figure 14% weaker roll bar ? I would love to see the math, welding weakens the metal some if you don't heat treat it afterwards
to realign the metal in the heat effected zone, I am short so hitting my
head on them is not going to happen.. Consider using seat belts ?
I built a slider for that roll bar protection.. tip ups don't have that in the same area, like the tipup / slider debate.. I love those handles on mine..


Danny..

I had handles welded into my rollbar as well. If you put them at the right angle, they pose little to no risk of hitting your nugget in an accident. I put mine angled up so they just clear the canopy frame as it closes. I can't really hold on to them when the canopy is closed, but that's not what they are there for, anyway. I use them EVERY time I get in, and they are priceless when giving rides. People naturally want to grab something up there, and if you don't put handles, they WILL grab the fiberglass.
In summary: 1. Definitely worth it. 2. If done right, no impact danger. 3. If welded, they won't weaken the bar.

Structural loss

godspeed said:

Whatever you used to figure 14% weaker roll bar ? I would love to see the math. Danny..

Click to expand...

The tube is 1.25" OD. Multiplied by 3.14 (Pi) gives a circumfrence (C) of 3.925". Wall cross section lost due to drilling holes is .25 (1/4") plus .313 (5/16") totalling .563". And finally .563" is 14 % of 3.925".

In other words at the point you drill the holes in the tube you immediately lose 14% of the steel in the cross section regardless of the wall thickness.

In reality the loss of structural capacity will be higher than 14% because the 14% reduction in the steel wall is not uniformly distributed...it occurs in specific locations (ie holes) thus creating elevated stresses under load in the zones immediately around the holes.

Make no mistake about it...drilling those holes will significantly weaken that roll bar...you don't need to be Einstein to work that out.

So what does your maths tell you?

My Meske roll bar hand grips are mounted
with #10 (.19 hole) screws. I'm lost, where did
the 1/4" come from? I think maybe looking at
an installation would help.
Tom

Off track

tomwebster said:

My Meske roll bar hand grips are mounted
with #8 (.166 hole) screws. I'm lost, where did
the 5/16" come from? I think maybe looking at
an installation would help.
Tom

Click to expand...

This thread was specifically discussing Aircraft Handles as supplied by Aircraft Extras. I refer to the product on their website:
http://www.aircraftextras.com/Handles1.htm
The installation instructions specifically call for a forward hole of 1/4" and a rear hole of 5/16".

You may have some other arrangement. If so please describe it or refer to it by URL.

I have Rich's handles and just checked his web site.
I suggest you do also. I don't think a clearance hole for a
#10-32 screw is 1/4". My point is please check your facts.
A signature would help also.
Tom

my math

if you don't like them don't use them, I respect your opinion but I don't agree.. 14% of the pipe not the strength , they are a great option and I recommend them fully..
once they go all the way through the bar and bolt from the backside
its stronger granted your way smarter than me.. evidently as I am
building an airplane in the garage / hanger .. how smart is that.. I never even considered using pi ,cake or cookies..

Danny..

I got my ideas from a bunch of SoCal guys already flying.

I bought some strong steel tubing and bent them to match the size of the the canopy latch handle and like the other guys said, placed them where I wanted them.

A welder friend for $50 drilled holes and welded them in place. Mine go all the way thru, to the front of the bar and a rossett (sp?) weld there.

I was just telling a passenger, 7a builder today, you need to watch how your knuckles rotate, you could inadvertly crack the hoop.

I am glad to hear the Meske's are working great. I almost bought a pair. Certainly simple and effective.

My homepage has a bunch of picts of my handles.

www.pbase.com/mark2nite

Loading Handles

I am currently in the research phase (deciding on the 7 or 8)soon to start the getting the shop phase started.

What about making the handles similar to those found on the Jeep's Roll bars. They are made from nylon and velcro. The do a great job as grab handles in my jeep. They would not pose any dangers from head strikes, or weaken the roll bar. There could be some kind of vision restriction, but not anymore than the metal ones,
Here is a link to what I am referring to.

http://www.offroadwarehouse.com/Store_ViewProdDetail.asp!ProdID!14462!Cat!1340

I am not saying to use these exect ones but something could be fashioned similar to these possibly and have them match your seats.

G. Moore
Cessna 177 owner
soon to be a -7 or -8 builder
Austin, Texas
www.silverwingsfly.com

tomwebster said:

I have Rich's handles and just checked his web site.
I suggest you do also. I don't think a clearance hole for a
#10-32 screw is 1/4". My point is please check your facts.
A signature would help also.
Tom

Click to expand...

Tsk tsk, you're being over defensive and splitting hairs. If you think I'm that far off the mark mathematically then why don't you come up with a set of numbers. What indeed are the "facts". Are you going to point out to me that the real loss of cross section is only 13% when I said it was 14%.

What I'm saying is that the Vans standard roll bar will be designed to withstand specific static and dynamic forces and that those forces will be quite modest in line with the aviation principle that structural redundancy and weight savings must always involve a trade-off.

When a builder drills holes in the roll-over bar he reduces the cross section and the end result is that it will buckle at a reduced level of force. The holes will effectively reduce the safety factor by some margin...that is the fact...whether I like it or not (and whether you like it or not).

I would further suggest that the roll-over bar in particular is not the place for RV builders to be practicing intuitive engineering given that the RV series are relatively short coupled aircraft with a definite tendency to tip over in accidents.

I highly recommend in this instance that builders who are contemplating drilling holes in the roll-over bar beyond those called for in the drawings contact Vans for their professional opinion.

It is relevant that Vans sent out a Service Bulletin not that long back mandating a mod to stiffen up the roll bar on the tip-up canopy...presumably due to failures in the field. This would indicate that there was not much redundancy in the original design.

I agree

I agree, I was being defensive because I already drilled the holes , too late for me.. sorry for disagreeing with you..

I love those handles though..

Danny..

Mine are similiar to the ones at AircraftExtras except they have a brushed aluminum finish. I believe the mounting screws were about 1/8".
I bought them at Lowes for a few bucks. You can find them in the cabinet section. I wouldn't do pull ups using them, but it does provide a leverage point for someone climbing into the front seat.