Montana Water Bombers

[ignomini]

At a recent fire in my area they were running the DC10s in mostly level flight. Everything else was running down hill. The MD80 was dropping gear down. I assume that was to help limit speed gains heading down hill.

[Stoney]

notice the water coming out of the side of the fuselage? they pick up more water then they can hold.

[leo]

Notice the gear down on the MD.
I am assuming to slow it down, more maneuverability? All the passes they made near us he had it down, except the first dry pass. In that one he was clean but wallowing through the turn a little. Next pass he flew over the gear was going down and the power was going up. Shook us so hard I thought we would lose windows but at that point he was LOW.
Fire got within a quarter mile so they were hitting it hard with the D, DC-10 and Bae's. Helped being within the approach of the tanker base, even though the big stuff was coming from out of the area (you can't tank a DC-10 at Stead).
I was too busy trying to decide when to get out of Dodge to take pics until it was almost over on our hill.

[Neal Nurmi]

'Tis the season...

We have 2 Lockheed Electras based at our local airport this summer. Very cool airplanes, even if not ex military. We live right off the usual approach from the west -- the airport is 5 miles away. It's 20 miles downhill from the passes to the west -- the Lockheeds have built up a pretty good head of steam when they come cruising past the house. -- very impressive indeed...

[Rajay]

The fuel required for that DC-10 in one run would last some old 2 and 4 engine recip planes for a week or so.

With the fuel required for that DC-10, a recip would not last 10 minutes.... Duh!

[exhaustgases]

The fuel required for that DC-10 in one run would last some old 2 and 4 engine recip planes for a week or so.

With the fuel required for that DC-10, a recip would not last 10 minutes.... Duh!

Makes lots of sense?
At what a gallon per second per jet engine (60 gallons a minute), versus a recip burning maybe 150 gallons per hour per engine at power. I'd like to know why they killed the recip water bombers? I suppose there maybe a few around still, but its like someone high up in government hates them.

[CoastieJohn]

Here is a USFS paper on the DC-10 used for fire fighting. They compare it against the P2V and have some good cost info.

https://www.nifc.gov/nicc/administrativ ... gPaper.pdf

From Wiki:
Civilian firefighting[edit]

P-2/P2Vs have been employed in aerial firefighting roles by operators such as Minden Air Corp and Neptune Aviation Services. The fire fighters can carry 2,080 gal (7,874 l) of retardant and have a service life of 15,000 hours. Neptune proposes to replace them with British Aerospace 146 aircraft which are estimated to have a service life of 80,000 hours and carry upwards of 3,000 gallons of retardant.[18]

[CAPFlyer]

The fuel required for that DC-10 in one run would last some old 2 and 4 engine recip planes for a week or so.

With the fuel required for that DC-10, a recip would not last 10 minutes.... Duh!

Makes lots of sense?
At what a gallon per second per jet engine (60 gallons a minute), versus a recip burning maybe 150 gallons per hour per engine at power. I'd like to know why they killed the recip water bombers? I suppose there maybe a few around still, but its like someone high up in government hates them.

He was being facetious. Jet-A in a radial or most recips are a bad combination.

A CF6 (engine on the DC-10) runs about 3000lbs/hr in cruise (or about 500 gal/hr), the PT-6A (AT-802) averages 50-60gal/hr for most versions, and the 501D/T56 (C-130/L-188/CV-580) runs about 125-150gal/hr (or 2.5gal/min).

[CoastieJohn]

Nice pic of the water bomber making a pass.

[exhaustgases]

[

A CF6 (engine on the DC-10) runs about 3000lbs/hr in cruise (or about 500 gal/hr), the PT-6A (AT-802) averages 50-60gal/hr for most versions, and the 501D/T56 (C-130/L-188/CV-580) runs about 125-150gal/hr (or 2.5gal/min).

So what is cruise setting 60%? A fire bomber is not at cruise settings.

[CAPFlyer]

Jets aren't the same as pistons. You don't cruise at a given "power". Power is a factor of best cruise performance for a given altitude.

While I don't have the full charts, looking at the Flight Planning Table for the DC-10-30 with CF6-50C2 engines, for a 2 hour flight at 10,000 feet (at 368 KTAS max cruise0), you plan a burnout of ~38,000 pounds for a landing weight of 320,000 pounds. For every 10K below that (I suspect they're operating quite a bit lower than that) you subtract 500 pounds off the burn, so the 38,000 is probably a good estimated burnoff for a typical attack flight within 2 hours of base.

[CoastieJohn]

Excellent, close up scooper vids....

https://www.youtube.com/watch?v=a5B4-JZA7FA

https://www.youtube.com/watch?v=6FGFW2yfdQY

https://www.youtube.com/watch?v=YZ_fQ13q3hk

Some helo action....

https://www.youtube.com/watch?v=sPsPJ6J8oFw

[Larry Kraus]

CAPFlyer,

I'm not sure if it helps in your calculations, but I happened to see DC-10 Tanker 910 enroute empty to Moses Lake, Washington for reload after dropping on the Nena Springs Fire on the Warm Springs Reservation in North Central Oregon yesterday. That's a distance of about 190 nautical miles. Just after crossing the Columbia River, according to Automated Flight Following the ground speed was 353 knots at an altitude of 12,450 feet. That appeared to be the final cruise speed and altitude for that leg.

[exhaustgases]

The numbers don't look right for 3 huge jet engines at a 38K burn in 2 hours.
So what is take off power approximate? And what is 10k hp in turbine terms? That's what I'm guessing engine out put is at
that fuel consumption.

[Larry Kraus]

For what it's worth, here are links to a couple of articles from the Fire Aviation website on the DC-10

http://fireaviation.com/tag/dc-10/

http://fireaviation.com/tag/10-tanker-air-carrier/

Here's one from a day or two ago on the old Aero Union P-3's maybe being put back to work

http://fireaviation.com/2017/08/08/a-fo ... surrected/