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  #1  
Old 03-01-2018, 07:41 AM
kelleyclark kelleyclark is offline
 
Join Date: Dec 2005
Location: Winter Haven, Florida
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Default Second Attachment Point for Dual Lap Belts

I am looking for photos, diagrams and advice on how and where to install second attachment points on my RV 7 for Hooker Harness dual lap belts with a ratchet tightener. I currently have the Hooker five point sport harnesses installed but need the ratchet tightener for sustained inverted flight. This requires the dual lap belt system. I have contacted Hooker, but they were unable to provide any information.

Thanks.
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Old 03-02-2018, 01:49 PM
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Subscribed as future capability considered!
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Old 03-02-2018, 05:16 PM
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I hope someone who has done this chimes in. I do know from prior posts that some have used the same attach point for both. Theory being the safety belt was there in case of accidental disengagement of the harness, not for a failure associated with the attachment.
Not ideal but the odds of the attach bolt or bar breaking away is pretty low, same for an outright failure of the webbing or harness hardware.

You might reach out to one of the IAC folks who post hear often or to one of the Team Aerodynamics folks like Mike Stewart and see what they do.
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Old 03-03-2018, 06:37 AM
kelleyclark kelleyclark is offline
 
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Hooker Harness also suggested I email Mike Stewart of Team AeroDynamix, which I did. His team has dual attachment points in some of the RV 8's but not in the side by side seating aircraft. Mike suggested I order additional seat belt anchors (F-635) from Van's. This is probably the method I will attempt. I am hopeful there is enough room to install them near the existing anchors. I will document the process and post it to this thread.
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Old 03-03-2018, 10:40 AM
zlinman zlinman is offline
 
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This is the biggest problem for competition style acro in a RV6,7. I flew a 6 for 2 years in competition and had trouble with this problem. First, stock attaches are not good enough for a ratchet. The geometry is all wrong. A ratchet ends up bending the rear spar carry through. I had to pull my floors and build reinforced attachments. I ended up with a single ratchet and no backup. Not ideal. Second problem is that there is no physical place for the second belt. If you have ever have flown a hooker in a real competition machine, you realize how the geometry is better. The belt has to pull you down, not back. The belt on the 7 is made for a forward impact not inverted flight. Remember, that what ever you come up with, it must hold at least 4 times your weight to be safe. Good luck. Terry Burch
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Old 03-08-2018, 09:35 AM
kelleyclark kelleyclark is offline
 
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Terry thanks for your input and advice. I installed and flew the Hooker Harness Aerobatic System in my Decathlon. It is a nice system with dual attachment of the two lap belts and a nice ratchet on one of the lap belts. Hooker's Sport Set for the RV's is nice for most flying but does not provide enough safety, backup and security for sustained inverted flight and aerobatic competition. Looks like the install of the dual belts with dual attachment points and ratchet in the RV 7 is going to take some more thought and engineering. I will press on.
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Old 03-08-2018, 01:32 PM
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"Although RVs are capable aerobatic aircraft, we do not recommend them for serious competition aerobatics...We recommend that RV pilots limit themselves to what we like to call 'sport' aerobatics; aerobatic maneuvers done solely for the enjoyment to the pilot rather than of spectators or judges. "

Van's Aircraft.

Of course, everyone is free to do what they wish...
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Old 03-15-2018, 06:23 PM
kelleyclark kelleyclark is offline
 
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Quote:
Originally Posted by RV7A Flyer View Post
"Although RVs are capable aerobatic aircraft, we do not recommend them for serious competition aerobatics...We recommend that RV pilots limit themselves to what we like to call 'sport' aerobatics; aerobatic maneuvers done solely for the enjoyment to the pilot rather than of spectators or judges. "

Van's Aircraft.

Of course, everyone is free to do what they wish...
RV7A Flyer,

I appreciate your input. Just to verify, are you affiliated with Van's Aircraft? Some reading this thread believe you are. I believe you are not and took your selected text from this link: http://vansaircraft.com/public/rv-flying.htm

There are members of this forum that are successfully competing in RV aircraft. I am not sure if I will compete, but when I fly inverted in my RV 7 I want to keep my body positioned firmly in the seat as I was able to do in my Decathlon. That is why I started this thread seeking input on the installation of a second attachment point for dual lap belts with a ratchet tightener.

Here is the entire Aerobatics section from the Van's Aircraft website:

Flying an RV (n.d.)
Aerobatics

Retrieved from http://vansaircraft.com/public/rv-flying.htm

"Aerobatic capability has always been important in any true sportplane. While aerobatic flying provides valuable unusual attitude familiarization, its main purpose is simply fun. It may be the ultimate expression of the uninhibited joy of flight. By virtue of their wide speed range and relatively low wing loading, the RVs are quite good aerobatic aircraft. Roll rates are in excess of 140 deg/sec for the RV-4, RV-7/7A, and
RV-8/8A and just slightly slower in the RV-14/14A. There is practically no adverse yaw - beautifully smooth rolls can be done with feet flat on the floor. The high inertia and low drag of the RVs permit nice loops at very low G-loads. It is possible to perform a series of aerobatic maneuvers at cruise power, not exceed 3 or 4 G, and gain altitude at the same time.

Although RVs are capable aerobatic aircraft, we do not recommend them for serious competition aerobatics. Their high speed is not suited to the restricted competition zones. In order to stay "in the box’’ they would have to fly slower and lose the benefit of inertia, or keep the speed up and pull too many Gs. Because of their low stall speed, the maneuvering speed (maximum full control application speed) is in the 135 mph range. Thus, aerobatic safety in the RVs is highly dependent on pilot technique.

The RV-3B, RV-4, RV-7/7A, RV-8/8A and RV-14/14A have been designed for the operational stress limits of the aerobatic category
(+6.0/-3.0 G) at and below their aerobatic gross weights. The operational stress limits for these aircraft between their aerobatic gross weights and their maximum design gross weights are utility category (+4.4/-1.75 G). The RV-9/9A, RV-10 and RV-12 are not designed for aerobatic flight.

The design operational stress limit for the RV-9/9A is utility category (+4.4/-1.75 G) at less than 1600 pound gross weight and is standard category (+3.8/-1.5 G) between 1600 pounds and the aircraft’s design gross weight. The design operational stress limit for the RV-10 is standard category (+3.8/-1.5 G).

No RV should ever be operated above its design gross weight limit.

We recommend that RV pilots limit themselves to what we like to call "sport" aerobatics; aerobatic maneuvers done solely for the enjoyment to the pilot rather than of spectators or judges. These maneuvers can be tailored to be gentle to both the airplane and the pilot. RVs can perform all the usual aerobatic maneuvers (loops, rolls, Immelman turns, horizontal 8s, etc.) very easily and gracefully at low G loads. They rarely need to dive to attain entry speeds. We have found, for instance, that in the RV-4, loops can be entered from level flight and successfully completed on 40% power. We could go on and on with such examples, but this should give you some idea of the effortless agility that awaits you in an RV."
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  #9  
Old 03-15-2018, 11:09 PM
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RV7A Flyer RV7A Flyer is offline
 
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I am most assuredly NOT associated with Van's Aircraft...not sure why anyone would get that idea.
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Old 03-16-2018, 06:15 AM
rapid_ascent rapid_ascent is offline
 
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I think it was just the way you signed the quote Vans Aircraft that kinda gave that impression.
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