September 3, 2000 Aviation Life Rafts, Part Three: Single-Tube Life Rafts

Email this article |Print this article

by	Doug Ritter

About the Author ... Doug Ritter is former News Editor of AVweb and now contributes on special projects. An experienced and respected aviation journalist, Doug is a contributing editor to The Aviation Consumer and Aviation Safety and a former contributing editor to Flight Training. He also writes for CODE ONE and AOPA Pilot, as well as other aviation publications. Doug is best known for his insightful product evaluation and comparison articles, his interpretation and explanation of complex technical and engineering concerns related to aircraft systems and products, and his in-depth investigation of aviation products, flight safety, and human factors issues. He is a leading expert in the area of aviation survival and a working member of the SAE Aerospace Council S-9 Cabin Safety Provisions Committee and S9-GA General Aviation Sub-Committee. Doug is also the publisher and editor of Equipped to Survive, a web site devoted to survival equipment and techniques. Articles in This Series Part One: Requirements and Expectations Part Two: A Life Raft Primer Part Three: Single-Tube Life Rafts Part Four: Double-Tube Life Rafts Supplement: Manufacturer Contact Information

In this four-part series, AVweb provides an in-depth look at aviation life rafts. We examine the regulatory requirements, the common-sense requirements and what you should look for when selecting a life raft. We also examine both the approved and unapproved rafts for the GA market and let you know which ones will more likely save your life if you ever need to use them.

Because of their lighter weight, smaller pack size and lower cost, most light aircraft and helicopter operators are interested in single-tube life rafts. Your options range from rafts that are not much more than an oversized inner tube with a floor to reasonably well-equipped sophisticated life saving devices.

Survival Products

Survival Products produces both unapproved and TSO'd Type II single tube rafts in similar configurations. The base unapproved rafts are little more than a single-cell tube with a floor, available in both four-person ($1,095) and nine-person ($1,425) size.

These square rafts have no ballast and only the most minimal entry aids, a token grab handle on the floor of the raft at the boarding point that is of little help in assisting entry over the 11-and 12-inch tube, respectively. The corners are constructed by bending the tube and then covering the resulting corner with seam tape. As we noted in Part 2 of this series, they still refer to these as "4-6 Man" and "9-13 Man" life rafts in some of their literature and on their web site. The latter number is the overload capacity and should not be used for normal purposes.

The very compact dark red valise has black text that is difficult to read. The mooring/inflation line is attached at one corner with Velcro and proved difficult for testers to locate. It has only a loop at the end and is too short.

An optional teepee style canopy ($175 and $220, respectively) is available that you must attach and erect via an orally inflated center mast. The mil-spec style oral inflation valve stymied many testers who were unfamiliar with its operation. Due to the angle of the canopy from the tube to the central mast, it is uncomfortable in the extreme. It also collapsed immediately in our weather tests, and leaked badly. No retro-reflective material is used on the raft or canopy. Placarding was poor.

The valise serves also as the drogue. If you purchase one of the three optional Survival Equipment Packs (SEPs), Standard, Standard Plus and Deluxe ($325 to $1,095 depending on equipment and raft size; all include the canopy), it is attached to the raft valise with Velcro and a plastic cable tie. Separating the valise from the SEP is not easy without some means to cut the cable tie. Until separated, it isn't much use as a sea anchor. It does a reasonably good job as a drogue until its Velcro seams catch on each other under surging conditions, at which point it becomes ineffective.

Included as standard are a manual bellows pump and cloth bailer, but no repair clamps. At 12 lbs. and 18 lbs., without the SEPs, these are the lightweights of the industry, in more ways than one.

Survival Products TSO'd Rafts

We obtained a sample of Survival Products' new four-person Type II, single tube, double-cell raft ($1,850 - $2,386 depending upon SEP). Since then, they have also certified an 8-person Type II of the same design ($2,490 - $3,195). The rafts are also available without a canopy and no SEP or just with the canopy alone, starting at $1,425 and $1,945 for the 4-person and 8-person respectively. Neither configuration is acceptable for use when an approved raft is required. (All pricing was obtained from the company's web site.)

The approved single-tube raft is not significantly different in design and construction from the original square, single-cell model. Added bulkheads and a different inflation mechanism give it dual-chamber capability. Getting in wasn't much easier. On the TSO'd Type II the lifeline is attached higher up on the tube on either side of the dual opposed entries and there is a grab strap stretched across the floor between the two entries. Neither was a great deal of help.

We didn't much care for their unique combination topping and pressure relief valves, mostly because they are located inside the canopy, once you erect it. On a positive note, by the time you finally get the manually erected canopy up, most of the excess CO² has already been vented. We still believe it's a bad idea, unacceptable according to some life raft regulations, but not the FAA.

The teepee style canopy is essentially the same. A plastic tab and loop system to secure the bottom made that task both easier and quicker. You still have to manually tie down and orally inflate the center mast, so we are at a loss to comprehend how they can refer to it as "self-inflating," unless the "self" is you. A water-activated locator light is Velcro'd in place on top of the tube in a corner.

Located under the center of the raft is a single large weighted ballast bag (121 lbs. capacity) with a flap valve in the bottom to hasten filling. It proved minimally effective at preventing the raft from flipping during the initial boarding tests and is otherwise totally inadequate to resist capsizing. The raft shipped a lot of water during boarding over its minimal 11-inch tube. The valise continues to serve as the drogue. Escaping the canopy with the raft capsized proved difficult and frightening for some as it collapsed.

Give SPI credit for creative thinking in their pursuit of smaller and lighter. The quoit for the heaving line is a fabric tube filled with polymer granules that expand when immersed. That the resulting floppy, sausage-like loop would be less capable in a real rescue would appear to be irrelevant, as might the fact that one split its seam, spilling hundreds of sticky, jelly-like polymer globules all over the interior of the raft, rendering the heaving line useless and driving us crazy.

Eastern Aero Marine

Eastern Aero Marine produces two series of single tube rafts. The "EAM" line is available in single-cell configuration in 2-3 person and 4-5 person sizes and in double-cell configuration in 6-8 and 12-14 person sizes. EAM never provided promised current pricing, despite numerous requests.

The TSO'd double cell "T" series is available as approved or unapproved, depending upon the equipment selected. They are available as just a basic raft, with no survival gear, as well as Part 121 or Part 135 equipped. A manually erected canopy is optional and is included when a TSO'd raft is specified. These rafts come in 2-, 4-, 6-, and 9-person sizes. We have tested both the EAM T-4 and EAM T-6 four and six person rafts which weighed in at 34 lbs and 49 lbs, respectively, with Part 135 SEPs.

As noted earlier, some of the EAM series rafts provide less than 3.6 sq. ft. per person at their maximum suggested capacity. For example, the EAM-5 is the same size as the T-4 approved raft, with less than 3 sq. ft. per person with five persons on board. The EAM-8 is the same size as the T-6, with less than 2.7 sq. ft. per person with eight on board. As with Survival Products, consider the second number as overload capacity, not rated capacity.

With the exception of capacity ratings and the single buoyancy cell of the smaller rafts, the two series are similarly equipped. These are octagonal (smaller sizes) or decagonal (larger sizes) single tube rafts with no ballast. A single lifeline runs around the interior of the raft, difficult to see or grasp when in the water. Entry aids are minimal, a loop of line hanging down and a grab handle on top of the tube, neither of which is a lot of help to survivors trying to board.

The canopy is manually erected using rods that are secured to the tube with loops and snaps and a central extensible mast. The canopy bottom is stretched over the tube and held in place with its elastic hem. On smaller rafts the telescoping aluminum canopy rods must be extended before use. In doing so they can be pulled all the way out and apart, held together only by an internal nylon string. Two small arrows marked on the two sections of rod are all that indicate correct alignment of the button and socket lock. The spring-loaded locking buttons often didn't work at first so the rods couldn't be locked in the extended position. Soaking for about 15 minutes laying in the bottom of the raft usually gets frozen locking buttons working. The snaps are screwed into wooden plugs that come loose and fall out in many instances. These problems are very common, in our experience.

In none of this testing, or our many other experiences with this canopy design, have untrained raft occupants been capable of properly erecting the canopy under ideal conditions. Moreover, it has generally taken approximately 20 to 30 minutes for them to improperly erect the canopy. The elastic bottom of the canopy on one EAM raft was so tight that it proved impossible to get into place. In the end, testers gave up attempting to erect the canopy after 33 very frustrating minutes. In stormy or windy conditions or at night when you need the canopy the most, you can pretty much forget about it, in our opinion.

We have also seen the lightweight coated ripstop nylon canopy itself start coming apart at seams. The single roll-up/roll-down entry is secured with fabric ties. The canopies are moderately effective in light rain conditions and make good shade shelters with excellent ventilation if the sides are up, but proved virtually worthless in our simulated storm conditions. A fabric water collection tube is included. No retro-reflective tape is fitted to either canopy or raft.

These erectable canopies are downright dangerous when the raft capsizes, and these rafts will capsize in anything but relatively calm seas. The canopy comes loose and can wrap around survivors trying to get out from under the raft, causing panic. The poles come loose and can rip clothing or skin, or poke out an eye.

Conical drogues on lines that are too short proved ineffective. Standard equipment includes a locator light that can be manually repositioned from the tube to the canopy, a raft manual, a bailer and a hand pump. The hand pump has proven problematic for us, with multiple failures and no indication from EAM that is has addressed the problem. SEPs are offered in Standard and Standard Plus configurations. These are attached to the raft with a tether and must be retrieved by survivors. In one instance, equipment in the SEP was lost out of the kit before it could be retrieved.

At NBAA in October 2000, EAM introduced its new "Alpha" series of life rafts. Among these was a single-tube Type II raft with a self-erecting single arch canopy, modest ballast bags and more sophisticated entry aids among its features. These rafts show considerable promise compared to the anachronisms that EAM has sold for so long. On the other hand, we must caution that we have discovered the hard way that there is a big difference between first impressions and actual performance.

Hoover Industries

Hoover offers a line of TSO'd Type II rafts with design features very similar, in fact almost identical, to EAM's. This isn't surprising since they owe their origin to the same engineer. The Hoover designs are second generation, so to speak, and they have some minor advantages over the original EAM designs. These rafts are available in 2-, 4-, 6-, and 8-person sizes with or without a canopy and Part 91, 121, or 135 SEP. We have tested the FR-4 Type II four-person raft, which with its Part 135 SEP weighed in at 32 lbs. Hoover declined to provide pricing for their rafts.

These rafts are equipped with four very modest "water ballast pockets" (80 lbs. total)). The ballast made the raft just barely more difficult to tip over, but it was only a matter of minute degree and it was not such a substantial difference that it made any practical difference in ease of capsizing. We rate them as virtually ineffective and perhaps better than nothing, but hardly adequate.

For entry aids, Hoover has a grip handle on top of the tube, one inside on the tube and the inside lifeline. They use a two-rung ladder with semi-rigid flat rungs. This entry aid isn't too bad in concept — we like the flat, weighted rungs — but Hoover defeats their efforts by not making the ladder long enough. It just barely hangs down below the bottom of the tube making it very difficult to get a foothold on them while still maintaining a grip on the grab handle(s). For some it was virtually impossible. The Hoover single-tube rafts were difficult to enter, but easier than the Survival Products or EAM rafts; still not adequate, however, in our opinion. Simply adding another rung would be a big improvement.

Canopy design and installation is very similar to the EAM rafts; however, the telescoping rods cannot be pulled all the way apart and are more easily lined up for locking in the extended position. Beyond that, testers have the same problems erecting the canopy.

The rafts are equipped identically to the EAMs, but Hoover uses a much better hand pump. As with the EAM, we lost some survival equipment, including four canopy support rods, out of the tethered SEP before it could be brought on board the raft.

RFD/Revere

RFD's "Navigator" is a lightweight (24 lbs.) unapproved, single-cell, "4/6 Persons" raft "designed specifically for the general aviation light aircraft market." Revere never responded to our numerous email and phone queries to obtain current pricing.

This raft is constructed of orange polyurethane single-coated fabric that Revere says meets the TSO specifications, though, quite frankly, we are skeptical. I was told by RFD in Belfast that they use a different fabric for FAA-approved rafts since their standard fabric doesn't meet the flammability requirements. In any case, the fabric appears adequate for the job. Like the Survival Products rafts, it is square, built using a one-piece, 9-inch tube bent to make the corners. Rather than seal the corners to maintain the shape, they are tied together with web strapping across the interior corners. The release of one of these corner ties would create serious problems.

Boarding aids consist of a rudimentary single-rung "step" and a vee-shaped interior boarding ladder with a two rungs. The end of the ladder is secured permanently to the floor of the raft. It could be cut loose to get it out of the way using the raft knife included in the SEP. While the entry aids are basic, they worked reasonably well for the relatively low freeboard testers had to deal with.

The Navigator is equipped with three modest ballast bags (28 lbs. capacity each, 84 lbs. total) one in the center of each side and the rear. While small, they do make a difference in boarding, but it is still all too easy to upset this raft.

The RFD Navigator came in a semi-opaque yellow nylon "suitcase" style valise. The Velcro seal was not very secure and was easily undone. It would come apart readily if snagged. The raft is not tightly compacted into the valise as with the other rafts and there was no tendency for it to "explode" if the seam was partially opened. The valise has an exterior pocket, 11-1/2 x 9-1/4 x 1-1/4 inches, that can be used to store additional survival supplies, a nice touch, especially since it is only modestly equipped with survival gear.

All text on the valise was in dark black on the yellow fabric. The instructions say to "attach cord to aircraft," but there is no means, such as a clip, provided to do so. The pull cord is secured under a Velcro'd flap. After turning the valise over a couple times and then reading the instructions, our volunteer tried to rip open the Velcro seams.

It is equipped with a rudimentary self-erecting canopy of teepee design. The non-stay-erect arch tube is an inverted "V" which is attached at the midpoint of the side tubes (side being defined in relation to the open front of the square raft). The arch is a single tube, bent in the middle. The canopy is glued to the outer edge of the buoyancy tube on the back and sides.

The entry flaps forming one side of the teepee are rolled up and secured back with 2-inch fabric tape (similar to "duct" or "gaffers" tape) when the raft is inflated. You must peel off the tape to release the flaps and close the entry. The entry seals with a single strip of one-inch Velcro on the vertical seam and two-inch Velcro in the horizontal bottom of the flaps. As with the Survival Products rafts, testers complained of the need to hunch themselves due to the steep angle of the canopy. The self-erecting nature of the canopy with the absence of any intrusion into the floor space is an advantage over the Survival Products rafts. There is no way to gain flow-through ventilation or lower the canopy completely if desired.

The sea anchor was missing on our demo raft, but is supposed to be wrapped around the gas cylinder, secured by 2-inch Velcro straps which hold it in place. The pictorial instructions for releasing the sea anchor are not very clear or easy to understand. We also didn't think it a particularly good idea to have to reach over the side and under the raft in order to release the sea anchor.

Winslow LifeRaft Co.

Winslow offers a range of single-tube rafts, starting with the single-cell, octagonal RescueRaft ($1,395/4-person) and double-chamber RescueRaft II ($1,945/4-person). The RescueRafts are available in 4-, 6- and 8-person sizes. The four-person rafts weigh in at 16 lbs. and 20 lbs., respectively, packed in their compact valise. The only difference is the inflation mechanism for the double chambers of the 'II model.

In essence, they have taken their more sophisticated Island Flyer single-tube raft and stripped it of all but the essentials (including the second chamber in the base model). That still leaves Winslow's excellent entry aids to assist entry over the high-freeboard 13-inch tube, but no ballast or canopy and just a single, top-mounted lifeline. Without any ballast, getting in can still be a bit of an effort for some, but easier than any of the other unballasted rafts. Winslow pointedly doesn't call them a "life raft" since they lack these accouterments.

You can add any regular Winslow feature or option, such as ballast or a canopy, though at some point you might as well just get the Island Flyer. A unique and potentially valuable capability is that the RescueRaft II is retrofittable to full Island Flyer specification, if you decide at a later date that you want a more capable raft, so your initial investment may not be wasted.

Standard equipment includes only an effective self-deploying conical drogue, an excellent, spring-loaded manual bellows pump, a raft knife, and a water-activated locator light but no raft repair clamp or bailer. A $99 "RescuePack" SEP is available that includes these as well as some other basic survival equipment.

Winslow's unapproved GAST "Island Flyer" ($2,625/4-person) and "Island Flyer Plus" ($2,995/4-person) are octagonal, dual-cell, self-erecting single-arch canopy designs. The only difference between the two is that the Plus comes with Winslow's unique viewports. The rafts are available in 2-, 4-. 6- and 8-person size. The base 4-person GAST weighs in at 41 lbs, our Plus model with its included options came in at 44 lbs.

Three large ballast bags (128 lbs. ea., 384 lbs. total) made for a relatively difficult-to-capsize raft. The GAST's entry aids feature a three-rung, center-supported ladder, a tube-mounted grab handle, and their "interior assist ladder," all of easily-grasped, two-inch webbing. Together these made entry over the 13-inch tube relatively easy for everyone.

The heavy canopy material is opaque, bright orange outside and light blue, supposedly a psychological advantage, on the inside. The GAST lacks headroom except under the arch; however, it is vastly superior to anything else in its class in terms of weather tightness. Hardly a drop came though their "Sure-Seal" Velcro'd storm flaps on the zippers. Pulls on all the zippers made closing up the canopy a cinch. The canopy is also convertible, so you can put the top down in good weather or for dry pick-up. A storm port/water collection tube is fitted. Both interior and exterior water activated lights are included.

What dribbles of water that did penetrate came through the seams of the three unique "viewing ports," clear plastic windows in the canopy that allowed light into the interior of the closed-up raft. These ports were the most popular innovation of these tests, both for contributing to a psychologically more comforting environment and as a potential antidote to seasickness, a serious concern. The double-acting center zipper and Velcro tiebacks made for much better ventilation while closed up.

On all the Winslow rafts the immediate action instructions hanging from the arch are bold text on bright yellow stock with a red-striped border, impossible to miss. They were complete and easy to understand. Other placards were also well positioned, for the most part, and were equally attention-getting and considered the most effective.

Winslow mounts a Pelican Products Magnum flashlight on the canopy arch leg in plain view for immediate access, which makes a great deal of sense to us. Winslow has also added retro-reflective material to the bottom of the raft as well as to the canopy itself. The self-deploying conical drogue was effective. A unique "righting locator light" is situated under the raft. It guides survivors to the righting location at night and provides some minimal illumination to see the righting instructions and Winslow's excellent righting aids.

Our raft was fitted with the standard, pretty comprehensive Basic General Aviation SEP, the optional ($200) inflatable floor, and the optional ($140) "StoreSafe" survival gear pockets. These storage pockets are a great idea, pioneered by Winslow, that get the survival equipment and supplies off the floor and keep them safe and secure. As with all Winslow rafts, you can get a seemingly endless selection of SEPs and options. Winslow usually runs specials with significant discounts off list at the major general aviation events such as EAA's AirVenture, Sun 'n Fun and AOPA Expo. That makes their prices a lot easier to swallow.

Conclusions

With Survival Products "you get what you pay for," noted one tester. While not necessarily always the case, you rarely get more than you pay for and such is the case with their rafts. They meet the letter of the regulations, more or less, and if that is your sole concern, they are the least expensive way to get an approved raft. Comparing them to their low-end competition from EAM and Hoover is not pleasant, all are sorely lacking. While the canopy isn't very good, at least it won't poke your eye out when the raft capsizes and it is much quicker to set up. All other things being relatively equally bad, the lower weight and price gets the nod, they are the best of the worst.

The base single-tube raft, sans canopy and SEP, is an affordable option for those traveling over warmer waters in good weather and within range of quick rescue and is far better than nothing. The dual chambers of the Type II-approved rafts are a huge plus over its single-cell unapproved sibling and the $330 additional is worth it, in our opinion.

The Winslow RescueRaft and Rescue Raft II are better rafts in many respects; higher quality, better entry aids, and much more freeboard, but not a lot more seaworthy with the exception of their more effective drogue. That's nothing to sneeze at, however. It could make a difference. The single ballast bag of the Survival Products Type II isn't enough to make much difference and is compromised by the potentially problematic sea anchor. However, the RescueRafts are a lot more money, unless you can pick one up at a show-special price, often hundreds of dollars cheaper. Then their advantages, for only two or three hundred bucks more, make it worth consideration, unless you feel you must have the canopy.

The RFD Navigator is not an inexpensive raft for what you get. However, the self-erecting canopy, crude though it may be; ballast, minimal though it may be; and boarding aids are a significant advantage over the rest of the single-cell bottom feeders from Survival Products and EAM. Moreover, it is light and small, an overriding criterion for some. It is the best of the single cell offerings.

Best in class isn't even close. The GAST Island Flyer takes top honors among all the single-tube offerings. While we wouldn't fly trans-oceanic with one, for most light aircraft use it is a good compromise and leads its class by a huge margin in capability, though you're paying for Winslow's quality and its top features. Moreover, you also must cope with the weight penalty accruing from all those nice features. The viewing ports are the best idea in life rafts since the self-erecting canopy itself was introduced. We recommend the inflatable floor option for use where waters are cooler.