Six Moon Designs Flight 40 FKT Backpack

At 44 Liters (2700 ci.) and 39 ounces for the Flight 40 Fastest Known Time (FKT) is designed to function as an ultralight backpack with the use of our vest system and our supportive and flexible hip belt. All together you've got a light weight pack that's comfortable up to 30 pounds. It has been tested with loads in access of 40 pounds with zero sag in either the pack or hip belt.

Flight 40 FKT Support Structure

Starting with a Vest Harness that offers excellent load carrying capacity on its own. The vest is attached to the pack in two places and, when tightened, is designed to pull the pack body up and into your back putting the load onto the vest system. When combined with the Hip Belt the pack will hold firmly to your body and keep the pack from moving around while hiking. The Hip belt articulation is accentuated by our unique closure. Each of our straps are independent and terminate at the buckle. This allows you to set different levels of tension between the top and bottom of the hip belt. Straps that don't have two adjustment points on each side and simply loop between the top and bottom of the belt will reset to a central position as you walk.

A Delron hoop stay inside the pack bag, provides enough support to enable load transfer with minimum weight. The bottom of the stay is directed back to a junction to the center of the pack. This junction provides a direct connection between the stay and the hip belt. Typically with ultralight packs, the stays and hip belt are separated by several inches of fabric. The result is that when weight is applied to the stay, the pack sags.

With the Flight 40, all of the downward force from the stay is transferred directly to the hip belt. With the hip belt and stay, the load radiates out over a large surface area eliminating pressure points.


• Deeper Side Pockets
• Shock Cord Compression
• Removable Hydration Sleeve
• Larger Shoulder Strap Pockets
• Removable Hip Belt
• Minimal Cntact Back Panel
• Top Loading with Dry Bag Closure
• Interior Zippered Stash Pocket
• Ten Exterior Pockets
• Daisy chain
• Elastic Lashing Cord
• Multiple Point Compression System
• Ice Axe Loop
• Dual Hydration Ports
• Delron Hoop Stay


Torso Sizes
Pack Dimensions
Maximum Load
Base Weight

16" - 22" | 38 - 56 cm
11"W X 7"D X 22"T
Green, Gray
30lb - 13.5kg
12lb - 5.5kg
Lightweight Backpacking
Long Distance Backpacking



Pack Body
Body Contact
Side Panels

420 Nylon robic™
3D Mesh
210 Nylon robic™
4 Way stretch


Pack Volume

Main Bag
Extension Collar
Exterior Pockets

Cubic Inches




Pack Weights

Delrin Stays
Hydration Sleeve
Yoke Vest UL
Hip Belt UL

Total Weight

22oz - 620g
3oz - 70g
1oz - 30 g
7oz - 200g
6oz - 170g

39oz - 1110g


Multiple Hip Belt Sizes

The Flight 40 FKT is available with our ultralight hip belt. It is constructed with dual pockets. Each pocket capable of holding 1 liter (60 ci.) of easily accessible gear. They are sized to be large enough to carry a small digital camera, GPS, snacks, sun screen or other items you need quick access too. Still they aren't so large as to get in your way.

The Ultralight Hip Belt belt is constructed from soft 1/8" thick 3D mesh. The Ultralight belt closes with our 4-Point harness. This provides a solid connection and eliminates bunching of the belt.




Waist Sizes


Extra Small

24" | 60cm

26"-32" | 65-80cm

6oz | 160g


26" | 65cm

29"-34" | 73-86cm

6oz | 160g


30" | 76cm

33"-38" | 84-96cm

6oz | 160g


34" | 86cm

37+" | 94+g

7oz | 190g


1) When choosing hip belt sizes, you'll want to leave a gap between the ends of the padded section of at least 5". If you're doing a longer multi-month hike, you'll want to extend that by several inches to accommodate weight loss.

Color: Gray, green

$235 No. 1540FKT

Color: Hip Belt Sizes: Vest style: