Thursday, December 31, 2009

Australia: bush fires continue



Bush fires continue in Australia. Bill Gabbert of Wildfire Today is reported on these bush fires, yesterday and again today.

Thanks Bill!

Wednesday, December 30, 2009

Up close and personal with DC-7 tankers: reflections

See, I told you it is complicated, Nothing is ever easy in the tanker business. (Larry Kraus to K. Tyler Miller).

What can I say about this magnificent airplane, her pilots, co-pilots and all those behind the scenes who keep Butler's three DC-7 tankers in the air, flying fires? I can say that I feel an affinity for these tankers because of their original service as commercial airliners. I don't know if I ever flew on a DC-7, but I was a passenger on planes of a similar size and vintage. So, in some sense, even before I began the series on the DC-7, I had a relationship with these aircraft.

What I have gained from writing about these aircraft is a love for these three tankers. Three tankers that I call magnificent. It has been a joy to get to know these tankers up close and personal. I also know that these tankers are loved by their pilots, co-pilots, those in the shop who maintain the planes, and the ground crews. A bond between humans and aircraft that ensures that these fire engines in the sky are flying. A bond that ensures that some of us can get to know these magnificent aircraft up close and personal.

There is a another bond, that is the bond among fire fighters, both in the air and on the ground. I think of this bond as the raison d'etre. Larry speaks of this bond:
We have a bond with the other fire fighters that we work with, both in the air and on the ground. There is a mutual respect similar to that which develops in a military unit that has been in combat. It's always a pleasure to work with people who know their jobs. We all know that we can depend on each other and we do so every day. There's a great deal of satisfaction in being a useful part of that team.
Nothing is simple in the world of flying tankers, those fire engines in the sky. I have learned a lot in writing this series about the DC-7 including but not limited to weights and balances, a view inside the cockpit, quick engine changes (Q.E.C.), and multiple door retardant systems. These are important, but the most important point that I want to pass on to you is what Larry kept saying to me over and over in our e-mail correspondence:
See, I told you it is complicated, Nothing is ever easy in the tanker business.
Larry should know, he has been piloting DC-7 tankers for some 27 years.

Monday, December 28, 2009

Wildfire season in Australia



I don't want to forgot our friends in Australia where it is wildfire season. For example, I recently read about fires that were burning last week in Port Lincoln in South Australia, go here and here for more information. The video that I embedded here, was just posted to Youtube the end of last week with some footage of the Port Lincoln fire.

Still to come on DC-7 tanker series

I took a short break for the Christmas holidays and will be finishing up my series, up close and personal with DC-7 tankers this Wednesday with my own reflections.

Thursday, December 24, 2009

The Shepard by Fredric Forsyth

A friend of mine told about this wonderful aviation themed Christmas story: The Shepard by Fredric Forsyth as told by "Fireside Al" and broadcast on CBC radio. This same friend sent my a link to youtube where the story is told in four videos with aircraft photos. I post them here with warm wishes to all for a happy holiday season and safe and happy New Year.

part 1



part 2



part 3



part 4

Wednesday, December 23, 2009

Up close and personal with DC-7 tankers: in action (2 of 2)

When I first wrote this entry in December 2009, there was a very nice 20 minute video on Patrick's Aviation from Bob Webb shot from the cockpit of a DC-7.  The Patrick's Aviation website has since been taken down. So I am embedding a couple of Bob Webb's You Tube videos shot from a DC-7 tanker.

I will never get a chance to ride in the cockpit of an air tanker, but thanks to Bob's videos, I can say that I have experienced what it is like to ride in the cockpit of an airtanker. Enjoy.

I will be posting my own reflections based on my experience writing this series on DC-7 tankers in a few days after the original date of the post (December 23, 2009).

Edited on November 8, 2016

Shot during the 2005 fire season, DC-7 Tanker. pilots are Webb/Rowe. 

Direct link to video by Bob Webb

Shot during the 2005 fire season southwest of Cedar City Utah, DC-7 Tanker. From Bob's description of the video: "flying down into a deep hole to get to the fire, not once but twice!"

Direct link to video by Bob Webb






Monday, December 21, 2009

Up close and personal with DC-7 tankers: in action (1 of 2)



Now for the fun stuff. Here is a sequence of photos (below) of Brian Lash and Rick Langstrom in Butler's tanker 66 on the Deer Ridge Fire near the Medford OR airport on or about September 22, 2009. Mike Bitney took these photos and sent them to Larry. It is a great sequence of photos. For those of you who are interested, here is a link to Warbird Information Exchange (WIX) where Larry posted these and other photos of tanker 66 and tanker 62 in action. There are some other nice action shots on this same WIX thread of tanker 62 in action in 2008 here.

I expect to make two more posts in this series of articles on DC-7 tankers, one more on DC-7 tankers fighting fires and a final post where I offer my own reflections. So, stay tuned. In the meantime, enjoy these photos.

So as not to confuse, the video is taken at Fox Field in Lancaster, CA (probably in 2007).

 
 
 
 
 
 

 
 
 

Friday, December 18, 2009

Up close and personal with DC-7 tankers: retardant drops pt 2 of 2

In my last post, I was writing about the Aero Union multi-door tank system (8 doors) used by Butler's DC-7's. I'll let Larry explain to you the sequence he goes through making a typical retardant drop:
To drop a full load at Coverage Level 6, I would have the co-pilot arm the tank system, and I would set the intervelometer to the 12 o'clock position (1), set the timer to 0.4 and set the doors to open selector to 8. Assuming that we'd gone through the Descent Check List while descending into the drop pattern I should be set. All that I have to do next is to determine the correct place to begin the drop and hold down the drop button (located on the yoke) until all of the doors open.
I know that there are times when tanker pilots must make an emergency drop of a retardant load. If an emergency happens near a tanker base, there is usually a designated place, e.g. coordinates, where emergency drops can be made. Otherwise, the pilot tries to look for a safe place -- no houses, no people on the ground, away from water sources, etc. -- to make the emergency drop. As I understand it, if a tanker pilot were to drop the entire load at once (aka a salvo) while making an emergency drop, the nose will do a sudden pitch up because of the sudden loss of 27,000 pounds of retardant. Often the pilots have a few hairy moments when this happens as they bring the tanker under control.


In the case of the DC-7, Larry tells me that emergency dump switch (outlined in blue in the photo) is centrally located on the cockpit panel. When Larry or his co-pilot lift the guard and activate the system by flipping the switch to the up position, the doors open at an approximate coverage level 5 drop. If I am thinking about this correctly, an added benefit is that an emergency drop at an approximate coverage level of 5 means that any pitch up of the nose of the tanker will not be nearly as bad as a sudden salvo of all doors at coverage level 8 (or higher). Larry provides some more details on emergency drops:

As far as having to jettison retardant in an emergency, it all depends on the severity of the emergency, the location and other local circumstances. In most cases, such as an engine failure deep in a canyon, there will be time for some quick (maybe 15-30 seconds) of trouble-shooting followed by determining if there is time (and the terrain allows) to fly to a suitable drop area. If we really are deep in a canyon, a suitable drop area will be anyplace nearby that doesn't contain a water source, people, vehicles or structures.

Again, it all depends on the circumstances. Generally, it will be possible to fly a few miles to an open area, but it's better for a spot on the ground to be covered with retardant than the flaming wreckage of an airplane. It would be unlikely that we would climb out of a canyon with 3 engines to carry the load to a designated jettison area. However, if the failure occurred enroute to the fire at altitude, that could be an option. There are also other emergencies not involving engines. Hydraulic problems being high on the list. I also once had a failure causing the loss of the fabric on the rudder on Tanker 62 during a drop run.

As I've mentioned before, nothing is ever easy in the tanker business.

Wednesday, December 16, 2009

Up close and personal with DC-7 tankers: retardant drops pt 1

The tank system used in the DC-7 is an Aero Union multi-door tank system with eight doors where each of the eight tanks holds 375 gallons.Up until now when I have written about retardant tank systems in use by firefighting aircraft (e.g. the Erickson AirCrane and the AT-802), I have written about constant flow tank systems with either one variable single door or multiple doors. As I understand it, both of these systems are controlled by computers. Where the PIC has only to set the desired coverage level and possible the quantity of retardant to be dropped. These systems are easier to use, but come at a price. According to Larry Kraus, an Aero Union constant flow variable single door system for the DC-7 would cost at least$250,000 (perhaps more), representing a significant hunk of change out of Butler's budget.


The panel shown in this photo is located on the co-pilots side of the cockpit. The red light over the drop arming switch marked "off" is constantly on until the tank is armed, in which case it goes off. By the way, this switch is configured the same way across all of Butler's DC-7 tankers. Moving on, the switch on the left side of the drop panel marked "Flow/High/Low has been disabled as they no longer use the flow feature.


 

The dial in the photo above is called an intervelometer. Larry uses this dial to set how many tanker doors open at once. In this photo, it is set to safe, meaning that the doors will not open, moving clockwise:

LFT is the four doors on the left opening at once,
RT is the four doors on the right, and
ALL is the salvo of all eight doors opening at once

Continuing clockwise, to open double doors at a time, the dial is set to 1-2, and to open a single door at a time, Larry sets the dial to 1.

Larry provided an interesting piece of history about the intervelometer: "As far as the intervelometer, it was a surplus military item, as were a number of parts in the Aero Union 8 door tank. It originally was used for selecting the firing sequence for air to ground rockets on fighter bombers."
 We are not done yet, there are two more dials Larry uses, one sets the interval between door openings in tenths of second when pilot-in-command (Larry) presses the drop button that is located on the top left side of the yoke. The second dial sets the total number of doors to open. Larry explains the settings in this picture:

"In this picture,they are set to 0.4 seconds and 8 doors. At 130 kts. and 150 ft. above the terrain, with the intervelometer set for single doors, I would get approximately a coverage Level 6, or 6 gallons of retardant every 100 square feet (a 10 ft by 10 ft area) on the ground."

On Friday, I'll be writing more about retardant drops, so stay tuned!


Monday, December 14, 2009

Up close and personal with DC-7 tankers: the cockpit


I don’t know about you, but I have always been interested in airplane cockpits. When I have flown on commercial flights, I often will sneak a pike in the cockpit as I am boarding the flight. My intent here is to present some of Larry’s photographs of the cockpit of his tanker, T-62, along with some selected DC-7 manual pages that Larry had on file in his working computer.

What I have done, with Larry’s assistance, is to take the graphic and numeric key of a typical DC-7 cockpit arrangement (prior to conversion to its current use as a tanker) and match up some of Larry’s cockpit photos with the numeric key for the graphic of the cockpit arrangement. First I present the two images of the cockpit arrangement graphics then I present his pictures.

Please don't forget to read the comment after the pictures.



 

 
cockpit (radio stack on left in foreground)


control pedestal (36)

control pedestal (36)

control pedestal (36)


pilot-in-command instrument panel (25)

engine instrument panel (26, above control pedestal)

co-pilot instrument panel (27)

main fire control panel (in 16, above engine control panel)

heater fire panel (2)

upper instrument panel (8)

forward overhead panel (3)

aft overhead panel (1)

As Larry told me recently, "see, I told you it was complicated!"

Saturday, December 12, 2009

Up close and personal with DC-7 tankers: former passenger cabin, floating beam


Before going any further, it is very important for you to know that this photograph of the passenger cabin of tanker 62 was taken before the ballast items were loaded.

Ok, moving on, do you notice the box like structure running across the cabin floor? That is, according to Larry, the floating beam. The floating beam secures the retardant tank to the aircraft. But Larry says that it is another important purpose, it helps to distribute the "considerable weight of the retardant tank (1,500 lbs.) and the retardant (27,000 lbs.) across the front and rear wing spars." Larry told me later that the floating beam acts like a shock absorber. As I understand it, by acting like a shock absorber, the floating beam will absorb the shock as the tanker is taking off, flying, and landing.

Not only is the retardant tank, located below the floor of the passenger cabin (in the belly of the tanker), attached by means of the floating beam, there are attach points fore and aft. Larry explains:

Along with the floating beam, the tank has attachments at the forward and aft ends as well. The four attach points at the floating beam distribute the majority of the weight of the tank and retardant to the wing spars, but there are also two attach points near the front of the tank on top near the outboard corners.

These attach to a reinforced area of the fuselage where the forward baggage compartment and the hydraulic compartments meet in a bulkhead. There are two similar mounting attach points at the other end of the tank where the rear baggage compartment meets the heater and air conditioning compartments  All of these are belly compartments below the floor of the passenger compartment.

These mounting attach points don't have the shock absorbing qualities of the floating beam and I've seen individual mounting bolts break on a couple of occasions. Nothing serious, but on a preflight check you can see the tank sag near the broken bolt when it's loaded. On the plus side, I haven't seen one break in the last 15 years.

Friday, December 11, 2009

Up close and personal with DC-7 tankers: former passenger cabin, ballast


 The image above is interesting to me for a couple of reasons. First, remember that Butler's DC-7's once saw service with the airlines. Obviously, part of the conversion process from passenger plane to tanker has been stripping the old passenger cabin. Moving on. Now in this photo it is obvious that there is something going on. This is Butler's tanker 66 and the gentlemen in the photo is Brian Lash, the pilot of T-66. Larry Kraus tells me that in this photo, taken on May 26, 2008, Brian is doing a preflight check for a maintenance test flight of T-66. More importantly, Larry sent me this picture because it shows ballast secured in place on the aircraft.

Ballast represents additional items (for example the tires in back of the cabin in the above photo), is carefully stowed and secured at specific points called fuselage stations to add weight to bring the aircraft within manufacturer designated weight and balance parameters. It isn't just the weight of the plane that is important but how the weight is distributed within the plane that is crucial for safe operations. For example, weight that is distributed too far forward will put the plane into a nose down situation with possible fatal consequences for the plane and crew. Aviation mechanics, aka airframe and power train or A&P mechanics, periodically reweigh the plane and then check the planes center of gravity. Once the center of gravity is known, there are calculations that are performed that determine weight and balance parameters. Then additional ballast is often needed to bring the plane within these weight and balance parameters.




The photo above, a little fuzzy, shows one of these fuselage stations (F.S. 860) for tanker 62. What this means, according to Larry, is that this station is "860 inches aft of the weight and balance datum (F.S. 0, located at the tip of nose of the DC-7)." As I understand the weight and balance datum is also known as reference datum and is:
an imaginary vertical plane from which all horizontal distances are measured for balance purpose (FAA, Aircraft Weight and Balance Handbook (2007), Glossary p. 5).
From this ballast station, F.S. 860, additional ballast stations (fuselage stations) and their assigned weights are calculated to assure that tires, parts, ladders, etc equal the required ballast. According to Larry T-62 carries somewhere around 1200 lbs. of ballast. Most of it is behind (aft) of F.S. 860 and some of it is forward of F.S. 860.

Larry wanted to show you a graphic from one of his DC-7 manuals (electronic files) showing the location of the fuselage stations. Unfortunately, computer troubles with the computer where these manuals are stored prohibit him from doing so. Thanks for the effort, Larry.

I want to close this article on ballast by letting Larry share with us about how the weight of the retardant tank (1,500 pounds empty and an additional 27,000 pounds when carrying 3,000 gallons of retardant) affects tanker 62's center of gravity (CG).

With the retardant tank installed, the DC-7 is out of the forward center of gravity range in the empty condition unless several hundred pounds of ballast is located right aft, or a higher total weight spread over the aft part of the fuselage. We originally used sandbags at the rear pressure bulkhead,which is as far back as you can go inside the pressurized cabin, just behind the seats in the old passenger lounge at the rear of the plane.

The weight varies from airplane to airplane. I think that it's around 660 lbs on tanker 62.We now carry spare tires.tools,parts and other supplies that are carefully weighed in place with the fuselage stations noted (in inches from the bulkhead forward of the cockpit) to be sure that we get it right.

The mechanics changed things around in T-62 this year after doing a new weight and balance and I think that they got the CG slightly too far forward. At least it felt that way on take-offs and landings.There's a heavy box that we can move fore and aft over several feet to easily adjust the CG, but it wasn't bad enough to adjust, although I thought about moving it a couple of feet aft to see if I was right, but the season ended before I got around to moving it.

References

A wikipedia entry on an aircrafts center of gravity and the related concept of weight and balance may be found here. A somewhat more technical publication (cited above) called the Aircraft Weight and Balance Handbook (2007) is published by the FAA and freely available on the web, Much of it is written for A&P mechanics and other aviation experts. But the first chapter or two have an overview that I could follow as well as a glossary.


Thursday, December 10, 2009

Up close and personal with DC-7 tankers: engine maintenance (2 of 2)

Here are some more photos from Larry Kraus off Q.E.C. stands either ready to install or just removed from the airplane. In order to provide a reference regarding the size of the Q.E.C's, a couple of the photos have people near by. Enjoy!

 

 

 

Up close and personal with DC-7 tankers: engine maintenance (1 of 2)


 

 

The other day Larry Kraus and I were continuing our e-mail exchanges about DC-7 engines when he shared some interesting details on the process of how Butler changes out a bad engine for a good engine. I had wondered how aircraft engines are replaced, so I was very interested in what Larry had to say:

One point of interest concerning the DC-7 engine installation is that the engine, prop, oil system (oil tank/cooler and all lines) and all of the accessories are mounted in a Q.E.C. (Quick Engine Change) assembly. The British call this Q.E.C. a "Power Egg". If you look at the Q.E.C./Power Egg, you can probably see where the term originated, especially if you think of the Q.E.C. without the engine stand.

The pictures here show an engine that Butler brought to us for Tanker 66 in Fairbanks in 1983. The engine itself weighs about 4,400 lbs. The Q.E.C. when it's ready to install weighs a bit over 6.000 lbs. These picture are in sequence, including photos giving a good view of what a Q.E.C. looks like out of the engine stand.

These really are Quick Change assemblies. The record for Butler for an engine change is truly amazing.I was flying as co-pilot to Laddie Lash in 1979 in the old Tanker 67 on a fire near Klamath Falls. We shut #4 engine down because of smoke from an oil leak and flew to Redmond. The problem would take a while to repair and a Q.E.C. was ready that had been run the day before on a test stand.

There were no complications and it took right at two and a half hours from the time we parked in front of the hangar to starting to taxi out for a test flight. The test flight went okay and we were back flying on the fire within four hours of shutting the engine down. That's a record,but it isn't unusual to have the old engine removed and the new one ready to run within four hours.

As I understand it, the Q.E.C. is used for many tankers, and the Q.E.C. can take some time to build. For example, Larry tells me that "It takes a long time to build up a Q.E.C. when you start with a bare mount and an engine in a can. For the DC-7 Q.E.C. at Butler, it takes around 3-4 months per Q.E.C. in the winter with two or three guys working on it."


Wednesday, December 09, 2009

Up close and personal with DC-7 tankers: power plant specifications

As I was looking around on the web recently to learn some history of the Douglas DC-7's when I ran across a couple of references to power plant (engine) specifications for the four engines on the DC-7. The specification was as follows:

4× Wright R-3350 18EA1 Turbo-Compound radial piston engines, 3,400 hp (2,535 kW) each

Now because of the reference to a 3,400 hp engine, I suspected that these power plant specifications where for the DC-7C not only that but some of the other specifications (not listed here) did not match those that Larry had sent me earlier. They appeared to be for a slightly bigger and heavier aircraft. So, I sent Larry Kraus an e-mail, I include his response below. But first I want to thank Larry for the time he took to write me and walk me through the incorrect power plant (engine) specifications. I am now slightly better able to read power plant specifications in the future. Here is what Larry says:
Our engines are a mix of civilian and military engines.The civil engines are either DA4's or EA1's. With 115/145 avgas,the DA engines were rated at 3250 hp. The EA's were used originally on the DC-7C and had some localized strengthening of the crankcase and improved mounting flanges for the PRT's that allowed an increase to 3400 hp (the C model was larger and considerably heavier than the DC-7.I think that the max take-off weight for the C model was 142,000.

We also use R-3350-42's and a couple of other dash number Navy and Air Force engines that were used on WV-2's and C-121's.These were military versions of the Lockheed Constellation. The P-2 also uses very similar versions of the R-3350. All of these engines are the Turbo-Compound models with the PRT's (Power Recovery Turbines).There are 3 PRT's per engine. They are similar to turbo-superchargers in that they use engine exhaust to spin a turbine wheel,however,instead of the tubine wheel being attached to an air compressor (to boost the air pressure at the carburetor), the PRT's are connected directly to the engine crankshaft via a fluid drive something like an automatic transmission in a car.

The main difference between the DC-7 engines and those in the P-2 is that the DC-7 engines use direct fuel injection with an injector on each cylinder and the P-2 engines use a single large injector into the eye of the internal supercharger that's driven by the crankshaft. I don't remember all of the dash numbers for the 3350 military engines that we use,but if it matters.I think that I mentioned it in my WIX thread somewhere. These are large engines with two rows of 9 large cylinders (18 total). R-3350 means a Radial Engine with a 3350 cubic inch capacity (the internal volume of the cylinders). A large 8 cylinder car engine might be 350-400 cubic inches.
The main point being that all of these engines (DC-7 and P-2) have been de-rated to 2880 hp while using 100 octane fuel. I'll attach a cutaway of a DC-7 engine from the Douglas manual (above) that gives a view of the PRT drive. It's a bit complicated, but the PRT's really do recover horsepower that's just going out the exhaust. With the 115/145 power, each of the 3 PRT's is said to have been worth 150 hp at take-off power.

So, if I were to say anything about the power plant on Butler's DC-7's, I would say the following:

Four 2,880-horsepower Wright R3350 engines.

Thank-you Larry!

This just in, I am adding a couple of posts tomorrow on changing out engines on the DC-7. Stay tuned for more.

Note: double click on the manual page to enlarge the view for easy reading.

Tuesday, December 08, 2009

Up close and personal with DC-7 tankers: specifcations


This is the first of two articles on specifications of Butler's DC-7's. Tomorrow I will post an article focusing on the power plant (engines) specifications.

Weights of aircraft

Gross weights: The weights of Butler's DC-7's are 113,000 pounds gross with 100/130 avgas. The actual design gross weight was 122,000 pounds gross with 115/145 avgas (no longer easily available). According to Larry Kraus: "the difference is due to reduced horsepower available with the lower power settings allowed with 100/130 avgas. Our take-off power with the higher octane115/145 avgas was 3,250 power per engine. It is 2,880 with the reduced power settings".

Landing weights: Landing weights for Butler's late models DC-7's (T-62, T-66) is 100,000. Larry says that T-66 (a DC-7B) "had some structural reinforcement around the landing gear and also for the flaps. The landing weight for Tanker 60 is 102,000. That airplane has the same power reduction as the straight seven's, so the maximum take-off weigh for Tanker 60 is also 113,000.

Normal take-off weight loaded with retardant: 108,000 pounds.

Turning diameter (on the ground)

I have seen references to the turning radius in specifications of various tankers, so I asked Larry about this. It turns out that the spec that I had from one of the USFS documents (72 feet 8 inches or a diameter of 145 feet 4 inches) was close. I was interested in his comparison of the turning diameter of the DC-7B with the turning diameter of the C-118A (the military equivalent of the DC-6B). He sent me a copy of the turning radius page from the only DC-manual that he has available along with a manual page showing the equivalent information for the C-118A because it shows that the outer wing tip clearance is 74 feet. I want to point out here that the simulator that Larry and his co-pilot use is a C-118A simulator. This is what Larry had to say about turning radii:
This is close to what the USFS info gave for the DC-7. As you can see, it all depends on what you use as a basis for the turning radius.The reason for the slightly larger radius for the DC-6 vs the DC-7,even though the DC-7 is slightly longer with the same wingspan,has to do with the nosewheel steering limits.The DC-7 nosewheel turns 71 degrees either way and I think that the DC-6 only goes 67 degrees.
 
As you can see, the turning diameter of the DC-7B is 142 feet 5 inches and the turning diameter of the C-118A is 148 feet 2 inches

And in an earlier e-mail he spoke about the tight turning radius of a DC-7:
It's tight enough that the airplane doesn't pivot around a locked wheel on the inside of the turn.The inside wheel actually turns backwards.It still amazes me sometimes how tight of a parking spot you can get the DC-7 out of using maximum nose wheel steering.
Fuel Capacity



I'll let Larry explain the fuel capacity of Butler's DC-7's:
The DC-7 and DC-7B with the larger capacity fuel system (top in the above page from the Douglas manual) can carry 5512 gallons of fuel.That's the capacity on Butler's 7's.Our normal tanker fuel load is between 500-600 gallons per engine in the main tanks and 50-75 gallons per engine in the alternates.That allows between 3.5 and 4.5 hour flying.Our oil tanks also hold 46 gallons of 60 weight oil each.Avgas weighs 6 pounds per gallon and oil is 7.5 pounds per gallon.
Retardant Capacity

Butler's DC-7's can carry up to 3,000 gallons of retardant.


Dimensions

I think that this Douglas manual page that Larry sent me showing the dimensions of the DC-7 is self explanatory so I attach it below without comment.

Note: Double click on the manual pages to enlarge the view for easy reading


Monday, December 07, 2009

Up close and personal with DC-7 airtankers: Introduction

 
 


I want to begin by introducing Butler's three DC-7 airtankers: T-60, T-62, T-66. Tankers 62 and 66 are straight DC-7's originally built for United Airlines. Tanker 60, on the other hand is a DC-7B that was built for Eastern Airlines. Larry's tanker, since 1983, is T-62. His co-pilot is Ron Carpinella. A two-person crew, pilot (aka PIC or pilot-in-command) and a co-pilot flies Butler's DC-7s, there is no flight engineer. While each crew has a primary tanker, they do flew each of the three DC-7 tankers. The picture below is the original data plate from Douglas Aircraft for the plane that eventually became T-62. Butler has contracts with the Oregon Department of Forestry (ODF) and with CAL Fire for its DC-7's. As I understand it, specific tankers are committed to specific state contracts. In 2009, T-62 and T-66 were on ODF contracts, where tanker 62 was based in Medford and tanker 66 was based in Redmond. Tanker 60 spent three weeks in 2009 based out of Chico CA on a call when needed (CWN) contract.

The first DC-7 flew commercially for American Airlines in November 1953. Passenger capacity ranged from 74 to 99 in the DC-7's and DC-7B's. I was interested to learn from Larry that "the wingspan was exactly the same from the DC-4 through the DC-7B,although the wing structure changed considerably between models.The fuselage length grew a great deal from the DC-4 through the DC-7 as well.

The heavier DC-7C was slightly longer allowing for an extra row of seats, increasing the passenger capacity to 105. The DC-7C also had longer wings allowing for a larger fuel capacity. By the mid- to late 1960s most major U.S. Airlines had replaced their DC-7 with newer jet planes on their coast to coast and international runs. For more on the history of this magnificent aircraft go here.


 

Early on in my writings on aerial wildland firefighting, someone sent me links to a two-part video starring the DC-7 airtanker. Watching these videos only wetted my appetite to learn more about aerial wildland firefighting. These videos were put together by Bob Webb, one of Larry's former co-pilots who has since moved on from Butler and is now a PIC in his own right. Being an aficionado of aviation history, I enjoyed the images showing historical pictures of various commercial DC-7 airplanes. You will also a couple of images of one of Butler's DC-7 tankers when it was used by United Airlines.  For the last several minutes of part 1, you experience retardant drops from the pilot's point of view (aka the left seat). There is also some incredible footage of a thunder storm. Allow about thirteen minutes to watch this video. It is an incredible video! It may be found here. Note on May 13, 2013, the original link for this video was on Patrick's Aviation, a few months ago I noticed that it was no longer around, but only recently did I find this same video on youtube, but without the audio. Still, you get the pictures and video.