Erickson Aircrane: intro, history and specs

When I started writing about aerial resources used to fight wildland fires six months ago, it did take me long before I saw pictures and videos of the Erickson Aircrane. The Erickson Aircrane is a type 1 helicopter (gross weight of more than 12,500 pounds, capable of carrying 11 to 16 passengers). The gross weight of the Erickson Air-Crane model S64-E is 42,000 pounds.

To provide a frame of reference, the Super Hueys that I wrote about recently are type 2 helicopters (gross weight up to 12,500 pounds, and/or carrying 8 to 10 passengers). The gross weight of H-301, one of CAL FIRE's super huey's is 10,500 pounds.

The Aircrane, when fitted with a fixed tank, is a helitanker. The Interagency Airtanker Board (IAB) establishes procedures and criteria for air tankers, helitankers, and tanks. According to section V (helitanker requirements)

helitankers shall be a Type 1 helicopter capable of lifting 1000 gallons of water at sea level (STP). Buckets will not be considered.

Erickson Aircrane has a very good web page chock full of information. The you tube video that I embedded above may also be found by clicking on the video link on their firefighting webpage (2nd video from the left).

This is the first of four or five posts that I will make about the Aircrane. Today I focus on history and specifications. In my next post, you will hear an Aero News TV interview with Kenny Chapman of Erickson. Among other things, Kenny describes the development of the Aircrane's fixed tank system and the Aircrane's firefighting capabilities.

Erickson has a web page where they write about the history of the Aircrane, here.

Specifications are shown in the image below for the two Aircrane models (accessed on June 8, 2009 from http://www.ericksonaircrane.com/index.php, design weights and performance page)

stalls and icing

One of the factors that can contribute to stalls is icing on the wings and tails of an aircraft. Simply, ice formation interferes with the normal aerodynamic flows over the wing and tail (aka horizontal stabilizer) leading to lower stall speeds and tragic outcomes. Yes, there are various de-icing systems that can be used in flight such as de-icing boots to rid the wings and tail of ice during flight. It is not my intention to get into the world of de-icing an in-flight aircraft.

In my travels on the internet learning about stalls recently, I happened on a link to aviation safety at a US Forest Service website and found a safety advisory from the Interagency Airtanker Board on icing. I found these safety reminders for airtanker pilots to be very poignant. As I read this advisory, what came home to me is that an airtanker pilot has the right to say “no” to flying into a situation where icing might be a problem and/or to get out of an icing condition before making a drop if called for.

Of course, I don’t know enough to know if airtankers even do retardant drops in northern States in America during cold weather where icing might be a problem. I am not an expert in meteorology, but I know enough to know that 33 degrees on the ground is going to translate to something colder at higher elevation. I also know that there is something called rime ice, which I think is caused by “freezing fog.” And rim ice can form on aircraft wings and tail.

Link to IAB safety advisory on icing (this is a pdf filerequiring a pdf viewer)

If that link does not work, go here and look under Interagency aviation safety alerts for advisory FS 09-01 on aircraft icing.

The advisory also provides a good description on ice formation as affects aviation that I found very helpful.

About AT-802F: Part 1

The single engine AT-802F, manufactured by Air Tractor, is widely used both in the United States and globally for wildland fire fighting for retardant and water/foam drops. The 802F is Air Tractor’s fire fighting model, equipped with special equipment adapted for wildland fire fighting, I’ll get to that a little later. There is also an 802, without this special fire fighting equipment, that is used primarily for agricultural use such as crop dusting. Go here for Air Tractor’s page on the AT-802. The “A” suffix added to the end, e.g. AT-802FA or AT-802A means that it is a single seat cockpit. There is an 802 and 802F that come equipped with amphibious gear for landing on water. These models are known as the AT-802 Fire Boss and the AT-802F Fire Boss.

Air Tractor has a web page on the AT-802F . I posted a link to the later page a couple of days ago, so if you have not checked out, check it out now. If for no other reason than to see some spectacular pictures of the 802F and the 802F Fire Boss in action.

I will be writing about the AT-802F (either the single-seat cockpit version or the two-seat cockpit version) as well as the AT-802F “Fire Boss”. These Air Tractor models have what is known as the Air Tractor Fire Retardant Delivery System (FRDS). I refer you to this link for more information on the AT-FRDS II system. I think it is self explanatory. What is notable about the FRDS system (aka the FRDS air tanker door system) is that it is the only SEAT door system that is approved for use by the Interagency Airtanker Board (IAB). All aircraft contracted for use for wildland fire fighting by the U.S. Forest Service (USFS) and the Bureau of Land Management (BLM) and other cooperating federal must meet IAB standards. TL Stein, aviation historian, tells me that

there are other systems available, including home-made systems in use that are not USFS or BLM approved. These other systems may be used by State aircraft or other 802’s not available for a nationwide tanker contract. Generally, the after-market and home made conversions are done on older aircraft where the installation of a FRDS system is not economically feasible or needed.

For a very good and short video of an 802F in action, including shots of the FRDS, check out this youtube video.

updated information (as of January 28, 2010). At the time that I wrote the above, I only knew about one approved SEAT door system approved by the IAB, the FRDS I system. Sometime in the last few months a newer model of the FRDS SEAT door system -- FRDS II -- was put on the market. At the time I wrote the original article, there was information available on the web through Air Tractor (I believe) on the FRDS I gate system that I linked to in February 2009. That link has since expired. With the advent of the FRDS II system I have not been able to find any obvious information on the net about the FRDS I system that is still being used in many AT-802F's (e.g. Queen Bee's). Moreover, I recently found out that there is another computerized SEAT gate system that has preliminary approval by the IAB, known as the Hatfield Gate. I expect to writing about the Hatfield Gate system in early February 2010, so stay tuned.