Question Taxiing over tie down ropes?

[Neal]

When parking at a FBO it concerns me when having to taxi over tie down ropes. My concern is something kicking up into the prop. I'm not sure if I'm just paranoid but what is your take on parking when there are tie down ropes you have to go over?

 

[Tsquared]

Never taxi over a rope. The consequence of it getting sucked into the prop or wrapped around the tail wheel is pretty high. Same for small chains used as tie downs.

I’ve shut down and pushed the plane into its parking spot to avoid taxing over a rope.

 

[Waldom]

Agreed.

Unless you're pulling a lot of power, there is little chance of the rope fowling the propeller. You are not doing the next user of the rope any favors, though. I suspect fibers breaking and dirt ground into the weave weakens ropes.

If you see rope left loose across the potential path of an airplane, that is a pretty clear indication of the safety culture of the operation. Some leeway should be allowed if there has been a high wind event in the past few hours and the general lack of airmanship of too many individual pilots. Coiling tie down ropes after use marks a knowledgeable aviator.

 

[midlifeflyer]

Where I used to be based, we used chains instead of ropes. That included chains along the ground the tiedown chains were attached to. We would pull the airplane across the ground chain before getting in. When asked why, the usual answer was to not power over the chains. My answer was to make sure we were not embarrassed by trying to move the airplane when one airplane was still tied down.

 

[Waldom]

Can't say I'm a fan of aircraft tie down systems that consist of chains attached to cables on the ground that run the length of a line of airplanes.

It is almost impossible to attach chains to an airplane without slack. Parked airplanes can rock wings in wind with slack in the chain and when they do the chain will put a very high load on the attach point of the aircraft because, unlike a nylon rope, the chain has no "give".

After a wind event, I have seen what once was a line of airplanes that were attached to a long cable in a large pile at one end of the cable. The cable held, though! The airplanes were turned into aluminum scrap.

 

[midlifeflyer]

It is almost impossible to attach chains to an airplane without slack

The cable ran along the ground along the entire line attached at multiple points along the way. It was heavy but had enough of its own slack that you would raise it up with your foot an inch or so when hooking the chain to the tie down ring. Wish I had a photo, but the result was the least amount of tiedown slack I’ve seen, including those ratcheting systems. It was in use precisely because of the very strong winds what would blow in Colorado’s Front Range, especially during thunderstorm season.
And it was far less prone to user error than ropes even though it was in fairly large ramp areas.

 

[kshunz]

Some years ago, our club SR-20 was damaged when the prop picked up a tie down rope that it taxied over.

 

[Waldom]

In the cable/chain tie down system that failed that I saw, the interim attach points had failed. Some other airplanes that were secured to individual anchors during that event also had that system fail, but not all of them.

I concede that chains attached to a gound cable with slack don't put as much G shock on an airplane with wings that are rocking in the wind. The problem with that is that the slack still allows the aircraft to rock more. Of course ropes attached to individual ground anchors that are left slack will have the same effect. The other problem with chains is the wear and cosmetic damage they cause to the aircraft where they are attached to the wing.

The Navy uses chains to secure their aircraft to the deck. Those chains all have tensioners on them that eliminate slack, although they are usually attached to the landing gear and not the wings of their airplanes. In addition to not having them blown off the deck in a typhoon, they need to keep the airplane within its precise footprint in that tightly packed space. Chains are often attached to two different anchor points for each landing gear to help facilitate this.