Photo mock-up of a DHC-6 Twin Otter in an air tanker configuration. Image via Viking Air Limited.Viking Air Limited has plans to provide an option to convert the Twin Otter DHC-6 300 and 400 aircraft into air tankers. The company has signed a contract with PAL Aerospace Canada to support the Twin Otter Fire Attack System, including the design, manufacturing, installation, and certification of the 700-gallon transformation. They expect the first unit will be delivered to an international customer in 2022.
Viking says the Twin Otter will be able to transition effortlessly between firefighting missions and its more traditional mission profiles of transporting passengers and cargo.
With over 50 years in the Canadian Aerospace industry, Viking is the manufacturer of the Twin Otter Series 400 and Guardian 400 Twin-engine turboprop aircraft. The company is the Type Certificate holder for all out-of-production De Havilland Canada aircraft (DHC-1 through the DHC-7) and all Canadair amphibious aircraft, including CL-215, CL-215T and CL-415 aerial firefighter aircraft, and the Shorts Skyvan, 360, 330 and Sherpa family of aircraft.
PAL’s website emphasizes aircraft engineering, certification, and configuring aircraft for special missions.
Thanks and a tip of the hat go out to Eric.
16 Comments
That will be an interesting engineering challenge since the fuel tank is in the belly
So, where are they gonna put the fuel cells, since they are currently located in the fuselage belly where the water is dumping out in the picture…..
In this photo, it looks to be a belly mounted tank.
DOH, now I see the Caravan-style cargo pod on the bottom!
That will be the worlds slowest tanker. Ferrying retardant at 2kts over stall speed.
Cool.
A twin-engine SEAT.
I have flown a Twin Otter, it is definably not a SEAT. The Otter flies like a, twin. I don’t know where the market would be other than what the Otter was intended for pax and cargo. Good comment, Doug.
Doug–
exactly my thoughts after reviewing the empty weight vs. max take-off weight and max knots airspeed… no more gallons of mud…
The only redeeming value is that it could take passengers after removing tanks, etc. Which we all know will never happen with the government.
Unless the max gross weight is upped by 3000#s, hauling 700 USG is a fantasy fuelled by delusion with some hopes and prayers thrown in for good measure and only then with a thimble of fuel remaining. For reference, a wheeled single seat AT802 will haul 800USG with 2000#(4 hours) fuel and true out at 170KTS give or take. Oh and also for 1/4 the price.
LOL
Is that like Good Idea Fairies, Cheap weed, and Unicorns?
Depending on configuration, weight and balance, etc may be able to carry pax with belly tank attached. Reckon delay would be taking seats, etc in/out?
Don’t get me wrong: I like twotters. My experience with them has been civil and military jump operations, and I’ve jumped them quite a bit. They’re versatile, utilitarian aircraft that fly well, are reliable, well designed, well built, and do well in their various capacities.
That said, Viking shows the payload for the aircraft, with a 100 mile range (low fuel load) at 4,061 lbs. At 9 lbs/gal, that’s 451 gallons, and at 9.6 lbs/gal that’s 423 gallons. How it can achieve 700 gallons and make it around the pattern is a bit of a mystery, if it stays within its 12,500 max gross takeoff weight. Having said that, twotters do run as tankers with floats, but the water is contained in the float.
Even straight water is only 507 gallons. Ambitious.
Of course, the same thing everyone else encounters is density altitude; we don’t fight fires from sea level in most cases, and retardant loads are reduced for performance based on the location. What the airplane will actually carry to the fire isn’t necessarily what’s advertised, and if carrying enough fuel to make multiple trips to the fire or meet contract fuel requirements, may be substantially less.
Many years ago I helped tank the Basler DC-3 (BT-67), using a detachable, external tank and drop system; it’s been some years but I think it was 1200 gallons. The concept was that the aircraft would be multi-use. I don’t know how much use it saw in any specific capacity, but given the issues associated with stress on aircraft flying the tanker mission, I question the willingness of the government/client to use the aircraft for jumpers or point to point, as well as a tanker mission. Helicopters do it, so it is done, but not typically in a fixed wing role. At least, not in the US.
I’m not dismissing Viking’s offering. I hope they manage a product that sells and sees use. They’ve done well with the CL-215/415 series and the new EAF, which is flying a lot. I’ll be interested to see what develops.
It’s worth noting that whatever they come up with, it will still have to meet drop test and patterning requirements, which has been a challenge for every system developed on tankers. Viking has a solid engineering team and does good work. I wish them well.
Not worth it for 700 gallons. Develop more 415s.
I had to check the date on the Press Release. My guess was that it would be April 1st.
No. I was wrong.
Apparently Viking and PAL are serious about this.
If my backyard barbecue has a flare-up, I’ll know who to call.
With a disposable load the Twin Otter now water drops at a gross weight of 15,500 lbs. They ferry them at 17,000 lbs and the Canadian Military does Search and Rescue Operations at 18,000 lbs. I’m sure it won’t be restricted to 12,500.
It seems like an odd choice for an air tanker. Pie in the sky? A niche tanker? Viking knows what they’re doing. STOL capabilities might be a plus as might the low stall speed. It might fit into really tight places both on the ground and on final. Drop tests? How about dump tests? A really big slosh in a tight place. LR
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