Thank-you Queen Bee and Moving on

I am, for the moment at least moving on. I am, at least for the time being, finished with my series of articles on "Up close with the AT-802 with the help of Queen Bee".

Before doing so, I'd like to thank all the folk at Queen Bee for your time in the form of e-mails, photos, and a telephone conversation. Thank-you!! I know that we will be in touch again, which I am looking forward to. And when that happens, I'll be writing more here.

In the next period of time, I'll be writing about a potpourri of either wildland fire and/or aerial wildland firefighting issues and/or more general aviation issues. With a little fun stuff thrown in such as the shovel-cam video that I posted the other day.

Up close with the AT-802 with the help of Queen Bee: Hatfield Constant Flow Gate System

Queen Bee has two AT-802's with the Hatfield Constant Flow Gate System. This is a more recent entry into the arena of SEAT gate systems. Like both generations of the FRDS, this Hatfield Gate is a constant flow retardant delivery system. According to the 2009 edition of the Interagency SEAT Operations Guide (p.39) the Hatfield Gate achieved interim approval of the Interagency Airtanker Board in 2009. I don't know more specific information about the operation of this Hatfield gate, when I do, I will post something here. In the meantime, Go here for some generalized information on how constant flow retardant delivery systems work.

Note: The Bureau of Land Management maintains a nice webpage on Single Engine Airtankers where I found the link for the 2009 edition of the Interagency SEAT Operations Guide (ISOG). They also have links to wealth of other information on SEAT operations. I mention this because I am thinking that the ISOG may be revised this year for 2010 in which case the link for the 2009 edition of the ISOG will expire. The BLM SEAT Operations webpage may be found here.

Thanks to my friends at Queen Bee for the photos!

Up close with the AT-802 with the help of Queen Bee: FRDS-I Gate System

Here is some information that I obtained from the Air Tractor website about the first generation Air Tractor Fire Retardant Delivery System (FRDS), a constant flow retardant delivery system, used by Queen Bee. Air Tractor is now into the second generation of the FRDS.

Introduction:
The Air Tractor Fire Retardant Delivery System, or FRDS, is an electrically controlled, hydraulically actuated constant flow airtanker door system. System operational parameters allow multiple constant flow drop capability at coverage levels between 0.5 and 4.0 gcf, with a maximum flow, or "full coverage" rate approaching coverage level 6.
Operation:
The system is operated by an onboard PLC (Programmable Logic Computer) which receives input from a pilot interface panel in the cockpit, the drop trigger, and various internal sensors. During a typical mission, the pilot will select the amount to drop (in 50 gallon increments) the desired coverage level (in 0.5 gcf increments) and ground speed. He then will arm the system and close the drop trigger when needed. The PLC will control the drop using sensors for door angle, flow rate, and acceleration to meter the retardant flow, closing automatically when the preset amount has been dropped. The system incorporates a "learning" algorithm to compensate for errors caused by wear, material viscosity, etc., making the coverage level self calibrating. In addition to the full automatic drop mode described above, a manual automatic mode is also available through the PLC. In this mode the PLC retains control of the flow rate to ensure accurate coverage level while the length of line, or drop quantity, is controlled by the pilot by simply holding the drop trigger closed for the desired distance. This mode is useful in operational situations such as when the pilot is instructed to "Put a line from the road to the rocks." The requested line can be dropped with minimum waste, saving the remaining
retardant for other targets.
Redundancy:
A redundant PLC is installed which provides for backup electronic control in a simplified manual mode. This system provides for continued operation in the event of a failure of the primary PLC unit. A mechanically operated pneumatic emergency jettison system is also installed which utilizes compressed air from a reservoir to force the doors open in the event of an in-flight emergency.
Components:
The FRDS consists of dual, centerline mounted, longitudinally hinged, overcentering type doors driven by a rotary type hydraulic actuator powered by a 3000psi electric hydraulic system with an accumulator. The system is controlled by a PLC via electric hydraulic controls and sensors for hydraulic pressure, door angle, door lock, acceleration, and tank quantity. Operation is controlled with a pilot interface panel in the cockpit. An 18 gallon class A foam tank, electric gauge, and automatic foam injector pump and controller are also mounted.

Obtained from the Air Tractor website on February 6, 2009. Note: The link that I used in last February no longer active, probably because Air Tractor is now into the second generation FRDS. Thanks to my friends at Queen Bee for the photos!

 

  

 

 

Up close with the AT-802 with the help of Queen Bee: Loading retardant

As I understand it the valves used for loading retardant in the AT-802F -- 3 inch male kamlock couplers -- are standard in airtankers. The federal SEAT contracts require dual valves, so that retardant can be loaded from either side of the aircraft. When used in the "agricultural configuration, there is only one valve, on the left side of the aircraft.

Thanks to my friends at Queen Bee for the photos!

Up close with the AT-802 with the help of Queen Bee: AT-802F cockpit

Here are some shots of the cockpit of the AT-802F courtesy of the wonderful folk at Queen Bee! Note that this a single-seat cockpit. A word on the AmSafe Airbag Harness, as I understand it this harness will deploy an airbag, for more information go here.

There are a couple of different models of the AT-802. The AT-802's equipped for agricultural "crop-dusting" spraying equipment are: the AT-802 (single-seat cockpit). The aerial fire fighting AT-802 is known as the AT-802F. Air Tractor makes a double-seat cockpit version of both models, designated by the letter "A". See this webpage for information on the AT-802 models.

Here are links on specifications and performance for the AT-802F. For those of you who want a more detailed discussion, I refer you to a couple of posts I made one year ago on the AT-802F (updated as appropriate) here and here.

Click on the image above for an enlarged and more readable version of the AT-802F dimensional drawings (courtesy of Air Tractor).

Up close with the AT-802 with the help of Queen Bee: About Queen Bee

Queen Bee Air Specialties has been in business for 45 years, and owned by the Kemper family for 33 years. Queen Bee has air tanker (SEAT) contracts with both national and state agencies. In addition, they have been an authorized Air Tractor Dealer since 1984, sell Air Tractor parts,  and perform maintenance services on Air Tractors. Information on Queen Bee's pilot flight training program may be found here.

Queen Bee's air tanker fleet consists of nine AT-802's, all of which are type III air tankers. Tankers are classified into four types based on retardant capacity (in gallons). A type III tanker has a capacity of 800 to 1,799 gallons of retardant (or suppressant). See page 52 of the Interagency Aerial Supervision Guide for more information on tanker classification. More information on Queen Bee's AT-802's see their web page on air tanker operations.

I've had the privilege of chatting with a couple of the staff at Queen Bee about their operations and the AT-802. They have been generous with their time and in providing me with some photographs, including the ones that I included here.

Thanks to my friends at Queen Bee for the photos!

Stay tuned for my next post where I will revisit specifications of the AT-802.

Up close with AT-802 with the help of Queen Bee: introduction

When I first began writing about aerial wildland fire fighting almost one year ago, I was interested in the aviation resources used by the New Jersey Forest Fire Service -- single engine airtankers (SEATs) and UH-1H Huey helicopters. So, after writing about Huey helicopters, I wrote about the different types of SEATS used in aerial wildland firefighting: AgCat aka FireCat, Dromader M-18, Ayers Thrush, and the Air Tractor AT-802, and the Air Tractor models 402, 502, and 602. Air Tractor is also in the process of developing a larger fire fighting SEAT, the AT-1002.

What I did not fully appreciate at the time I wrote those articles is that the smaller Air Tractor models, in particular the AT-502 and 602 play a role in agricultural applications as well as fire fighting. In addition, at the time I wrote those early articles, I may not have mentioned that SEATs fall into one of two tanker classifications dependent on the size of their retardant tanks. SEATs with tanks holding 799 gallons of retardant or less are called type IV tankers. SEATs with tanks holding 800 gallons fall into the type III classification.

As time went on my appreciation for the role of SEATs in aerial wildland firefighting grew. While I don't know specific details of states other than NJ, I do know that other states have SEATs on state contracts during fire fighting season. I hope to write more about the role of SEATs in fighting fires in my own state later this year.

It didn't take much time for me to learn that SEATs play a very important role in initial attack as well as being able to maneuver in spaces where larger tankers can not. Another advantage is shorter runway requirements and the ability to work from mobile "temporary" bases set up near a fire with mobile retardant mixing and loading trailers.

For sometime know, I have been wanting to go back and write more about SEATs. I am going to write about the type III SEATs. I hope to spend some time with the type IV SEATs later this year. With the single engine AT-1002 still under development, I believe that only type III SEAT is the AT-802 with an 800 gallon retardant tank. So, I begin with that AT-802.

When I wrote about the AT-802 last February I was looking for some more information about how these airplanes were used in firefighting. One of my air tanker pilot friends referred me to the Queen Bee Air Specialties website because Queen Bee is an Air Tractor dealer and they are active in aerial wildland firefighting. Queen Bee is one of several SEAT aviation companies holding national SEAT contracts.

Since I was already familiar with Queen Bee through their website, when I decided that I wanted to write more about the AT-802 contacting Queen Bee seemed like a good place to start. I was aided in this by a friend who put me in touch with the folk at Queen Bee.

I want to say here that I have the highest respect for all operators of aerial wildland firefighting aircraft, including but not limited to SEAT operators. As time goes on, I hope to have the opportunity to correspond with other SEAT operators in the future.

My focus in this series of articles, still being developed, is twofold. First, I hope to get up close and personal with the AT-802 with the help of the folk at Queen Bee. In the course of doing so, I will be writing about Queen Bee.