The Seek Outside Flight One Backpack is a lightweight 61 liter internal frame backpack that weighs 2 pounds 4 ounces. With a max recommended load between 35 – 50 lbs (depending on torso length and frame height), it’s built to withstand hard use for wilderness backpacking and thru-hiking. The Flight has a lightweight aluminum frame, an adjustable-length hip belt, and all of its exterior pockets are made with solid fabric to avoid the ripped mesh that plagues so many lightweight backpacks. The pack is available with two different fabric options: SpectraGridHT (which we explain below) or a combination of SpectraGridHT and XPac, that make the Flight highly abrasion-resistant and virtually waterproof. The Flight One is the first internal frame pack produced by Seek Outside, which is primarily known for their lightweight external frame backpacks. That expertise is clearly manifest in this awesome new backpack.
Specs at a Glance
- Weight: 2 lbs 4 0z
- Volume: 61L (3700 ci)
- Gender: Unisex
- Frame: Internal
- Closure: Roll Top
- Pockets: 6, including hip belt pockets
- Hydration compatible: Center hose port
- Load lifters: Yes
- Bear Canister Compatibility: Yes, depending on the model, canisters can be stored vertically or horizontally inside the pack, or secured to the top with a Y-strap.
- Materials: Solid SpectraGridHT – tested (also available in XPac with SpectraGridHT pockets)
- Torso Range: 15″-21″ (see below)
- Hip Belt Sizing: 26″-38″, 36″-48″
- Max recommended load: 35-50 lbs, depending on frame height and torso length
Backpack Storage and Organization
The Flight One a 61L rolltop backpack with two side water bottle pockets, each capable of carrying 2 x one liter bottles and a large front stretch pocket that’s good for storing extra layers or wet gear. All of these pockets have elastic at the top to keep their contents from jumping out and drain ports at the bottom. The water bottle pockets are 12″ deep, but reachable while wearing the backpack if you use a tall soda or Smartware bottle.
The pack’s hip belt has two large pockets with waterproof zippers. Seek Outside doesn’t count the side pockets or hip belt pockets in their volume calculations, so the pack feels like a *big* 61 liters in volume. The hip belt pockets are really oversized and dwarf my largish Smartphone. Each one is 8″ x 5″ x 3″ (close to 2L each.) I fill mine up with navigation equipment, my Smartphone, sun gloves, a head net, Tenkara fly fishing tackle, chlorine dioxide tablets, a CoVid mask, and anything else I need to access during the day so I can retrieve it without having to stop and take off my pack.
The main compartment is cavernous but lacks any internal organization. There are two hang loops on the inside that you can hang a water reservoir from, with a central hose port between the shoulder straps. There’s also a frame sleeve to hold the aluminum frame, but you’re probably not going to ever want to remove the frame because it makes the pack what it is. That frame sleeve has a cavity/opening that you could use as a pocket for smaller items, but it’s not really large enough to hold a higher capacity hydration bladder.
Bear canisters do fit inside the Flight, which is a huge plus for a pack that weighs so little. For example, my black Garcia canister fits horizontally in the extension collar with plenty of slack left over to roll the rolltop closed. It doesn’t fit vertically though due to the shape of the frame, which has a significant arch. Both the Bearvault BV450 and the BV500 fit vertically, according to Seek Outside. There’s also a top Y-strap that can be used to lash a canister to the top of the pack, which is pretty standard on roll-top packs
While the main compartment closes with a roll-top, the ends of the roll-top only clip to each other, not to buckles on the pack body. While one of the benefits of a roll-top pack is expediency, a second is top compression, which is lacking on the Flight because the roll-top doesn’t clip to the pack bag. While there is a top Y strap that runs over the roll-top, I found that the roll-top would unfurl when the pack was not completely filled to the gills. It’s not a showstopper, but I wish there was some way to secure the ends of the roll-top to the sides or front pack bag with gatekeeper clips instead. It’s just not possible given the pack’s current buckle setup. Short of that, adding a stiffener or snaps to the top of the extension collar would help prevent the top from unraveling. As it is, you just need to check it a few times a day when you stop to take a break.
The exterior of the pack has three tiers of fabric loops along the side and rear seams so you can run up to three tiers of side compression straps along the sides, or around the back (which is handy in winter for carrying snowshoes). The Flight comes with extra compression webbing straps for this purpose. The compression straps have gatekeeper buckles at the ends so you can move them from one set of loops to another. If you squeeze these buckles the little metal gate pops open so you can detach them and move them from loop to loop. For compression or gear attachment, I prefer webbing straps over the use of cord, which is common on many UL packs. I think it’s much easier to use and provides much more compression. A lot of brands use these buckles now, but Seek Outside was one of the first to introduce them several years ago on their Gila 3500 Backpack (see review).
Backpack Frame and Suspension
The Flight One is a fixed-length internal frame backpack with an aluminum perimeter loop. It’s not a U-shaped stay, but a 360-degree loop, not unlike those used on Seek Outsides external frame backpacks. Mid-way down the back, there’s also a horizontal stay, called an intrusion bar, that stiffens the frame and creates a cavity behind your back. Depending on your fit, that cavity can provide a ventilation benefit to keep your shirt drier in warm or humid weather. Seek Outside could have covered it with mesh, but adding cute features to their packs isn’t in their DNA.
The Flight Shoulder Straps are sewn to the back and come with load lifters. The straps are backed with soft spacer mesh and J-shaped. Unfortunately, the front of the straps do not have sewn-on daisy chains to attach accessory pockets or navigation equipment to, although I bet you could ask Seek Outside to sew some on for you. There are however plastic buckles sewn near the top of the strap that you can hang a small biner from (for an inReach, for example).
The Flight Hipbelt has a center buckle with a top and bottom adjustment strap on either side so you can make the top tighter or the bottom half of the hip belt depending on the shape of your hips and preference. The hipbelt is removable and attached to the pack with velcro behind a very soft and unobtrusive lumbar pad.
The two halves of the hip belt are themselves attached with velcro and so you can adjust the hipbelt length. The hipbelt is surprisingly soft and supple and lined on the inside with spacer mesh. Its 4″ width is beefy but not as wide as the hipbelts found on Seek Outside’s other external frame and hunting backpack backpacks. The hip belt wraps my hips well and I haven’t noticed any slippage, even when carrying loads north of 45 lbs.
Torso Size x Frame Length x Max Recommended Load
The Flight One is available in two different frame lengths: 22″ and 24″ that have different load-carrying characteristics depending on your torso length. This isn’t something you’ll find on other internal frame packs which take a one size fits all approach to maximum recommended loads regardless of frame height and torso length. Whether that actually reflects reality is another matter. This chart copied from the Seek Outside website summarizes the relationship. My torso length is 19″ and I tested the 24″ frame because I like to option to go heavy on certain trips.
|Torso Length||Frame - 22"||Frame 24"|
|18"||45 lbs||50 lbs|
|19"||40 lbs||50 lbs|
|20"||35 lbs||45 lbs|
|21"+||30 lbs||40 lbs|
The nice thing about having a 2 lb 4 oz backpack with a max recommended load of 50 lbs is that you can do heavy water carries with it. To test this out, I loaded up the pack with my regular backpacking load, food, fuel, and fishing gear, plus 10 liters of water to see how the pack would carry with 45 lbs in it. I was very surprised that the hip belt didn’t slip or buckle under the load since it doesn’t have any stiffeners sewn into it. I’ve had to carry loads like this in the past on long unsupported trips and really suffered because my pack’s frame and hipbelt did buckle under the weight. But the Flight One handled it with surprising ease and I’m pretty sure I could have carried even more, up to its 50 lb weight rating or even beyond it.
The Flight On is available in solid SpectraGridHT or a combination of XPac and SpectraGridHT. What is SpectraGridHT? It’s 100 denier high tenacity nylon with a PU coating that has a 200 denier Spectra fiber reinforcement with a very tight grid pattern, creating a highly water-resistant fabric. Spectra is in the same class of Ultra High Molecular Weight Polyethylene (UHMWPE) fibers as Dyneema and highly abrasion-resistant. Because the Spectra fibers are bigger than the Nylon in SpectraGridHT, they take the brunt of abrasion, performing similar to 500 denier Cordura.
Seek Outside’s SpectraGridHT also has a hydrostatic head of 1500 mm, which is much more than other backpack fabrics with the exception of Dyneema DCF and XPac. If the Flight One were a tent it would be considered waterproof, except for the fact that Flight One’s seams are not seam-sealed. While you’ll still want to line the pack with a pack liner, the Flight isn’t going to absorb much water when it rains, so you don’t need a pack cover too. If you’re trying to decide between the all-SpectraGridHT pack versus the pack made with a combination of XPac and SpectraGridHT (on the exterior high-abrasion surfaces), the SpectraGridHT is recommended for drier and rockier locations.
Comparable Lightweight Backpacks
|Make / Model||Volume||Max Load||Weight||Price|
|Seek Outside Flight One (XPac)||61L||35-50 lbs||34 oz||$299|
|Seek Outside Flight One (SpectraGridHT)||61L||35-50 lbs||34 oz||$319|
|ULA Circuit XPac||68L||35 Lbs||39-47 oz||$320|
|Elemental Horizons Kalais XT||52L||45 lbs||42.8 oz||$360|
|Gossamer Gear Mariposa 60||60L||30-35 lbs||31.2 oz||$260|
|Hyperlite Mountain Gear 3400 Southwest||56L||40 lbs||35 oz||$345|
|Osprey Exos 58||58L||40 lbs||42.4 oz||$220|
|Osprey Levity 60||60L||25 lbs||31.2 oz||$270|
|Superior Wilderness Designs Rugged Long Haul 50||60L||40 lbs||31 oz||$269|
The Seek Outside Flight One is a 61L lightweight backpack that weighs 2 lbs and 4 oz but can haul loads between 35-50 lbs, depending on the frame length you purchase and your torso length. It’s ideal for what I would term wilderness backpacking where you are hiking on-trail or off, without frequent resupplies, and you need to carry heavy or bulky loads like extra water, packrafting equipment, and bear canisters. The Flight would be equally at home on any triple crown trail particularly if you have or want to do heavy water carries, carry bulky equipment, luxury items, or extra food. In terms of comfort, I can’t think of any backpack I’ve reviewed in the past few years that comes close to the Flight One, particularly in terms of hip belt fit and ventilation. I love the flexibility of the external attachment system, the fact that the pack has functioning load lifters, large hip belt pockets, and the durability and waterproofness of the SpectraGridHT fabric.
The only tweaks I’d recommend making to the pack would be to add daisy chains to the upper half of the shoulder straps and adding a stiffener or snaps or even velcro to the roll-top to keep it reliably closed when the pack is not “bursting at the seams”. Those are minor changes you could probably ask Seek Outside to make for you, but they don’t significantly detract from the awesomeness of the Seek Outside Flight One Backpack. Highly recommended!
Disclosure: Seek Outside provided the author with a backpack for this unbiased review.