
At just 220g when you put it on it’s like there’s nothing there – hence the name, says Marcus King
“Never change your Slip” reads the strapline of the adverts for this ultralight hike-and-fly harness, hinting that it’s as comfortable as a well-worn favourite pair of underpants.

The harness weighs just 220g in the ML size we were sent, in line with the Neo String 3 and Advance Strapless 2 but twice the weight of the Ozone F*Lite. But this feels more like a harness for regular use than a super specialist harness. It shares a similar geometry to the others, that we first saw on the original Neo String.

The Slip uses Dyneema cord for the load-carrying skeleton, with a cord running down the centre of your back in addition to the two leg loops and one behind your back that most designs share. Inside this is the harness material that you sit on. The leg material is shaped so that the Dyneema loops aren’t taut, so they don’t cut into you. Nitinol rods in the seat keep the leg area open on take-off to make it easier to get into the sitting position without the material getting rucked up, so the load is better spread.
The ‘shoulder straps’ are made from glider line and are not load-bearing. They are there just to keep the harness in place on launch. They can be adjusted by sliding a knot up or down. The only other adjustments are a ball-and-loop system on the side to make the harness more upright, and the option to disconnect the lower strap between the two leg loops.
There are also elastic walking-pole holders, and loops on the sides to accommodate the airbag, which has a passing resemblance to a Bumbo baby floor seat! It has a mesh pocket on the back for storing a simple backpack. You can also fold the harness into the pocket for storage, although for me this was a similar experience to trying to get a two-man tent back in its bag, and I didn’t use it.
You can either keep all the straps connected and step into the harness or undo the leg loops then clip them in when the harness is on your back. Colour coding makes sure you don’t clip in to the wrong side. It’s easy to move around in on launch, and it is good for those forward-launch runs. Charlie and I shared the ML Slip during the review period – no sniggering please – and we both found it comfortable to use.

The harness is now supplied with Edelrid’s new Ease superlight karabiners that weigh just 22g each. They are wire-gate krabs with a rotating plastic piece that locks them closed. Our test harness did not have these, but we borrowed Slip from AirDesign which did. They work and have been fully tested, but they are bit unnerving compared to good old screwgates!

In the air the harness is perfectly comfortable with no pressure points. The deep seating position wraps you up and feels nice and secure. I did find the sitting position a bit upright, I think partly due to my height, but Charlie made the same comment.
I asked Nicolas Cochet from AirDesign about it and he explained: “An upright position helps give even back support. We also wanted to keep it quite upright for safety reasons: visibility, increased yaw stability with unstable wings, ease of standing up on landing while keeping a deep seating position in flight.” Being upright also helps if you are flying with heavy mountaineering kit on your back.
AirDesign Le Slip
Hike and Fly Harness
Weight: 220g
Retail price: 312.00€ including VAT, with karabiners
This review was published in issue 220 (June 2021)