Author Topic: B17 had longer range than the B24 liberator. (Read 740 times)

Mugzeee · « **on:** November 02, 2004, 01:28:05 PM »

Not really. But the new B24 in AH2 has substantually shorter range than the B17 in AH2. I ran 2 test in AH2 MA. All testing on both planes were...Full throttle/Auto take off/No flaps/Auto climb to 5,000ft./Auto level/in same direction from the same base and no manuvering/12x500 lbs bomb load. After the cruise alt was acheived auto level was engaged. From there i watch the (Range) using the E6b feature. Test #1 @25% fuel the B17 got 131 mile range and the B24 got 109 mile range.
Test#2 @100% fuel the B17 got 547 mile range and the B24 got 463 miles of range. Is something wrong?

ra · « **Reply #1 on:** November 02, 2004, 01:33:58 PM »

Sounds like it.

Pongo · « **Reply #2 on:** November 02, 2004, 01:38:59 PM »

yup. I dont know what the ranges are supposed to be. But I upped with 25% in a liberator formation and had to land it. On climb out the range was showing 74 miles. I know it would increase when I leveled at alt but I fubared my damage per sorti score by landing all three. It does climb as well with 50% as the B17 does with 25 though. Or nearly so.

Angus · « **Reply #3 on:** November 02, 2004, 02:33:55 PM »

The B24 should have considerably more range.

Mugzeee · « **Reply #4 on:** November 02, 2004, 03:51:59 PM »

http://www.acepilots.com/planes/main.html#top

Specs of B-24J (key differences from B-24D in boldface)

Four Pratt & Whitney R-1830-65 fourteen-cylinder radial engines, rated at 1200 hp, with GE turbosuperchargers
Performance: Maximum sustained speed 278 mph at 25,000 feet.
Service ceiling: 28,000 feet.
Range: 1700 miles at all-up weight of 61,500 pounds.
Fuel capacity: 3614 US gallons.
Dimensions: Wingspan 110 feet 0 inches, length 64 feet 2 inches, height 18 feet 0 inches, wing area 1048 square feet.
Weights: 38,000 pounds empty, 55,000 pounds gross, Maximum takeoff weight 71,000 pounds.
Armament: Bomb bay could accommodate up to eight 1600-pound bombs.
The late model "D"s included eleven .50 caliber machine guns: three in the nose, two in the belly turret, two in a tail turret, two in a dorsal turret (just aft of the cockpit), and two in the waist.

Heres a better link for comparison.
http://www.ww2guide.com/usab.shtml

Here it seems that the B17 has better range. But i just a D wings channel show that stated that the B24 Could "Fly farther and faster while carrying a bigger payload. Go figure.

Then again the spec sheet on this link is comparing them whith much different bomb loadouts i think.

United · « **Reply #5 on:** November 02, 2004, 05:14:22 PM »

The B-24 did, and should, have considerably more range than the B-17.

B-24- 2,200 miles (3,540 km)
B-17- 1,100 miles (1,760 km)

This is from several different sources.

http://www.aviation-history.com/index-aircraft.htm

Krusty · « **Reply #6 on:** November 03, 2004, 11:51:26 AM »

First, no bombers ever made long range missions by ramming the throttles to the stops then leveling off at 5k.

1) You need to reduce throttle, even when climbing

2) Higher alt brings better fuel efficiency (so, say bare minimum 10k, better 15k, best 20k+)

Use cruise or max cruise, NEVER use full throttle for anything other than takeoff. Try that.

I think (think, mind you, not sure) that it comes down to the B24 engines having more efficient cruise settings, and using less gas at those settings while at high alt. The result means that the B24 can fly longer than the B-17, but not if you ram the throttles to the stops (which many will do, no doubt)

Mugzeee · « **Reply #7 on:** November 03, 2004, 09:15:48 PM »

Quote

Originally posted by Krusty
First, no bombers ever made long range missions by ramming the throttles to the stops then leveling off at 5k.

1) You need to reduce throttle, even when climbing

2) Higher alt brings better fuel efficiency (so, say bare minimum 10k, better 15k, best 20k+)

Use cruise or max cruise, NEVER use full throttle for anything other than takeoff. Try that.

I think (think, mind you, not sure) that it comes down to the B24 engines having more efficient cruise settings, and using less gas at those settings while at high alt. The result means that the B24 can fly longer than the B-17, but not if you ram the throttles to the stops (which many will do, no doubt)

So is it your contention that the AH2 B24 has a longer range thatn the AH2 B17?
If so...please figure out how to acheive this and post your findings. Thanks.

Overlag · « **Reply #8 on:** November 04, 2004, 06:35:52 AM »

Quote

Originally posted by Krusty
First, no bombers ever made long range missions by ramming the throttles to the stops then leveling off at 5k.

1) You need to reduce throttle, even when climbing

2) Higher alt brings better fuel efficiency (so, say bare minimum 10k, better 15k, best 20k+)

Use cruise or max cruise, NEVER use full throttle for anything other than takeoff. Try that.

I think (think, mind you, not sure) that it comes down to the B24 engines having more efficient cruise settings, and using less gas at those settings while at high alt. The result means that the B24 can fly longer than the B-17, but not if you ram the throttles to the stops (which many will do, no doubt)

exactly so, the B24 flys much futher at maxcruise settings than i could ever get a b17 to do

at least so far in my testing

MiloMorai · « **Reply #9 on:** November 04, 2004, 08:58:21 AM »

Some data I found

B-24 - B-17

bomb load: 5000lb - 4000lb

range: 1700mi - 1850mi

endurance: 7.3hr - 8.7hr

avg speed: 233mph - 213mph

fuel cap.: 2364gal - 2810gal

auw :61,500lb - 63,500lb

Bodhi · « **Reply #10 on:** November 04, 2004, 12:28:03 PM »

Ok, I took the B-24 flight manual out, and here is the exact data as printed in it, last revised April 10, 1944:

Model B-24 G, H, J and PB4Y-1 aircraft with R-1830-65 w/ Ceco Carbureutor.

Range for:

Max weight 65000 - 60000lbs.
Max fuel of 3614 Gallons

2550 RPM or Emergency High Speed Cruising
46 in Man. @ all heights
TAS @25 k = 266, @20k = 258, @15k = 249, @10k = 239, @5k = 230, @SL = 223
1383 Statute Mile
1200 Nautical Miles

2350 RPM or High Cruise
36in @20k, 35.5in @15k, 35in @10k, 34.5in @5k, 32in @SL.
TAS @20k = 225, @15k = 211, @10k = 202, @5k = 193, @SL = 181
1890 Statute Miles
1640 Nautical Miles

2250 RPM Med alt Cruise
34.5in @15k, 32in @10k, 31.5in @5k, 31in @SL.
TAS @15k = 207, @10k = 191, @5k = 183, @SL = 174
2360 Statute Miles
2050 Nautical Miles

2050 RPM for 5k or Low Alt Cruise Long Range (think Polesti Raids)
1900 RPM for SL
31in Man @ both alts.
TAS @5k = 177, @SL = 164
2620 Statute Miles
2270 Nautical Miles

Note these setting are all from page 92 of the Flight Ops Manual for the B24 G, H, J, and PB4Y-1 and are for MAX load out.

If you want more, I will post the low end load outs later.

Schutt · « **Reply #11 on:** November 04, 2004, 04:29:35 PM »

How much bomb load is listed for max load out with that amount of fuel?

Bodhi · « **Reply #12 on:** November 05, 2004, 12:53:07 PM »

It is listed as maximum internal ordanance

RAF Liberators · « **Reply #13 on:** November 06, 2004, 04:10:59 AM »

Just as a point of interest the longest flight in a Lib was done by a member of the RAF, I know a veteran that was on the crew.

Krusty · « **Reply #14 on:** November 06, 2004, 02:13:48 PM »

Quote

Originally posted by Mugzeee
So is it your contention that the AH2 B24 has a longer range thatn the AH2 B17?
If so...please figure out how to acheive this and post your findings. Thanks.

Mugzee, do your own test. It's right there in the E6B.

I posted in response to your other post as well, but will also post in this one.

You can carry that much gas, IF YOU HAVE NO BOMBS!, the gas was always a compromise between weight of gas and weight of bombs. We have 2793 gallons in our b24. Accept it. And I'll tell you WHY this is a good thing.

Did tests on fully ladden B24 and B17. 1000lb boms (6k and 8k) and full gas. I'm not going to even mention full throttle, as those settings are the worst for gas economy.

I took the plane up to 20k, and tested the GPH and the speed.

B17 (total 2780 gallons): Normal Power: Speed: ~147, GPH: 416
(2780 / 416) * 147 = 982.3 miles range

Max Cruise power:

Here's the deal. Max cruise had SO LITTLE power in it the autopilot was losing alt because it was below the stall speed. It was running at 113MPH and falling. YOU CAN NOT RUN AT MAX CRUISE WITH BOMB LOAD, IS ONLY FOR RETURN TRIP! Also, I dropped the bombs and still it was too heavy to remain in level flight at 17k with full gas load. CONCLUSION: B17 CANNOT EFFECTIVELY RUN AT MAX CRUISE!
GPH: 311 Speed: < 110
(2780 / 311) * 110 = 982.3 miles

B24 (2793 total gas): Normal Power: 560GPH Speed: ~176
(2793 / 560) * 176 = 877.8 miles

Now you may think "see! See! Less range!" But wait, there's more. Note the speed? The B24 produces enough power from its engines to allow even reduced fuel consumption without loss of lift. On full bomb load and full gas load, no less, the B24 can cruise at Max Cruise easily.

Max Cruise: 348GPH, Speed: ~163
(2793 / 348) * 163 = 1308.21 miles

Whereas the B17 can't maintain LIFT at max cruise, the B24 extends its range by about 20% and still has a damn decent speed at alt.

Don't go b*****ing about things if you don't even bother to check them out for yourself. B24 is much more gas effective than the B17 in AH2.