Heavy bombers: B-17G vs. He 177A-5

[Lumpy]

It has often been argued that Germany lacked a heavy bomber, and that the Luftwaffe suffered for it. The He 177 Greif is often dismissed as a failure in this regard due to the engine problems of the A-1 model in 1942. However, the engine problems were largely fixed with the A-3 model using the new DB 610 engine. And the early 1943 A-5 version was definitively an excellent heavy bomber. During the “Little Blitz” bombing campaign against Britain from January to May 1944 the Luftwaffe bomber force as a whole  suffered almost 60% losses, but only 10% of the HE 177’s were lost.

I’ve desided to compare the He-117A-5 with its most prolific and celebrated allied counterpart, the B-17G.




B-17G Flying Fortress


Crew: 10
Length: 74 ft 4 in
Wingspan: 103 ft 9 in
Height: 19 ft 1 in
Wing area: 1,420 ft²
Empty weight: 36,135 lb
Loaded weight: 54,000 lb
Powerplant: 4 × Wright R-1820-97 "Cyclone" turbosupercharged radial engines, 1,200 hp each

Max. speed:  300 mph at 30,000 feet (war emergency)
Cruising speed:  182 mph

Armament: 13 x .50 cal machineguns.

Max internal bomb load: 8,000 lb
Typical bomb configurations: 2 x 2,000 lb, 2 x 1600 lb, 2 x 1000 lb, 12 x 500 lb , 16 x 300 lb, 16 x 250 lb, 24 x 100 lb

Range with max. internal bomb load: 1,098 miles
Range with reduced bomb load: 1,850 miles
Range with “Tokyo tanks” and reduced bomb load: 3,630 lb



He 177A-5 Greif


Crew: 5
Length: 72 ft 2 in
Wingspan: 103 ft 1 in
Height: 21 ft
Wing area: 1,092 ft²
Empty weight: 37,000 lb
Loaded weight: 68,340 lb
Powerplant: 2× Daimler-Benz DB 610 (twin DB 605) 24-cylinder liquid-cooled inline engines, 2,950 hp each

Max. speed:  351 mph at 21,000 ft
Cruising speed:  210 mph

Armament: 2 x 20 mm MG 151 cannon, 3 x MG 131 machine gun, 3 x MG 81 machine gun

Max internal bomb load: 13,227 lb
Typical bomb configurations:  48 x 154 lb, 10 x 1,102 lb, 6 x 2,204 lb, 2 x 5,511 lb, 3 x Hs 293 remotely controlled missiles, 3 x Hs 294 remotely controlled glide bombs, 3 x PC 1400 glide bomb, 4 x torpedoes

Range with max. internal bomb load: 1,920 miles
Range with reduced bomb load: 3,417 miles

[Karnak]

I doubt the internal load of the He177A-5 was 15,000lbs.

In addition, the engine problems were never solved, they just weren't as bad as they were in the A-1.  The He177 was a failure as a warplane.

[Lumpy]

The He177 was a failure as a warplane.

What do you base that on?

[Lumpy]

I doubt the internal load of the He177A-5 was 15,000lbs.

You're right. It was 6,000 kg (13,227 lb). 15,873 lb was the max. load including external ordnance.

[AquaShrimp]

How could the operational payload of the He177 be that high?  It had 400 less feet of wing area than the b-17.

Even the B-17 could carry 18,000 pounds of bombs under max-payload conditions.  But it wasn't practical.

I know the He-177 never cured the problem of its engines catching fire and burning right through the wing spar.  Most of the engine overheating problems could be traced to the exhaust ducts and leaky fuel lines.

[Lumpy]

How could the operational payload of the He177 be that high?  It had 400 less feet of wing area than the b-17.

Even the B-17 could carry 18,000 pounds of bombs under max-payload conditions.  But it wasn't practical.

The B-17 could carry 17,417 lb using external racks, but range and performance was very reduced so it was only used on a few occasions against targets in France.

I know the He-177 never cured the problem of its engines catching fire and burning right through the wing spar.  Most of the engine overheating problems could be traced to the exhaust ducts and leaky fuel lines.

Not at all. The fire problem was with the Daimler-Benz DB 606 fitted to the A-0 And A-1 series. The main production A-3 and A-5 series used the much improved Daimler-Benz DB 610 engine. There were still some problems with the transfer gearbox and flame damper tubes, but these were maintenance problems, nothing that was fatal to the aircraft.

[AquaShrimp]

I'll have to dig it up, but this subject has come up before.  One of the engineers of the He177 was quoted as saying that a 90 degree bend in an exhaust tube caused the engines to become inordinately hot.

A quick search on wikipedia : 

There were several reasons for the flammability of the DB 606 engine one of which was the common exhaust manifold on the two inner cylinder blocks which became excessively hot and caused the usual accumulation of oil and grease in the bottom of the engine cowling to catch fire.

[Lumpy]

Again I guess that is regarding the DB 606, not the DB 610.

"The paired engines had first been introduced on the single-propeller equipped Heinkel He 119 prototype reconnaissance bomber aircraft, to reduce drag where they worked well, but their extremely tight installation on the He 177 led to considerable problems, the most common being in flight engine fires and overheating. There were several reasons for the flammability of the DB 606 engine one of which was the common exhaust manifold on the two inner cylinder blocks which became excessively hot and caused the usual accumulation of oil and grease in the bottom of the engine cowling to catch fire. When the pilot throttled back there was a tendency for the injection pump to deliver more fuel than was required by the engine, in addition to which the injection pump connections leaked. In order to restrict the aircraft's weight, no firewall had been provided, and the DB 606 was fitted so close to the mainspar that there was insufficient space for the fuel/oil pipelines and electrical leads. The engine was frequently saturated by fuel and oil from leaking connections. At altitude, the oil tended to foam partly as a result of the oil pump being overly effective, and in this condition it circulated in the engines, its lubricative qualities being severely reduced. The lack of adequate lubrication resulted in the disintegration of the connecting rod bearings which burst through the engine crankcase, puncturing the oil tanks which poured their contents on to the hot exhaust pipe collector. The tightly-packed nature of the engine installations also led to very poor access to the engines. As a result of these factors, as well as a lack of routine maintenance in the field, the DB 606 easily caught fire in flight. Thus the effort to create an adequate engine to power the He 177 (such as the Junkers Jumo 222 produced too late in the war), by mechanically coupling pairs of lower-power engines, while theoretically sound, proved to be difficult and time consuming to perfect, leading to engine complications especially on the initial production models.

Starting with later versions of the He 177A-3, a modified engine nacelle with a new engine, the Daimler-Benz DB 610, was used to attempt to eliminate tendency for the engines to catch fire. Several improvements concerning cooling issues for the engines by setting a power limitation resulted in greater reliability. This modification was somewhat successful as far as engine fires were concerned but there were other minor problems with the transfer gearbox between the two engines and their shared propeller and other difficulties involving flame damper tubes."

[MiloMorai]

bomb load put of the He 177

[Widewing]

Well, the He 117A-5 was an excellent bomber, fully sorted and quite capable. However, the A-5 is a 1944 vintage bomber, better compared to the B-29 rather than the B-17 which was flying in 1935 (Boeing  299).


My regards,

Widewing

[Lusche]

These are the contemporaries of the B-17:


Ju-89 (1937)


Do-19 (1936)

The first He 177 had it's maiden flight in November 39, more than four years after the B-17.

[Lumpy]

Well, the He 117A-5 was an excellent bomber, fully sorted and quite capable. However, the A-5 is a 1944 vintage bomber, better compared to the B-29 rather than the B-17 which was flying in 1935 (Boeing  299).


My regards,

Widewing

1943 actually, and that is why I chose the B-17G as a comparison and not the B-17C or some other early war version. Contrary to what Lusche seems to advocate this thread is not about the technicalities of which bomber was best, but whether or not the Germans had a capable heavy bomber during the war ... something many seem to not believe.

Edit: And the B-29 is a lot bigger than both the B-17 and He 177, so it's not suitable as a comparison. The Ju 390 is better suited for that comparison, but only a handful of Ju 390's were built.

[Lusche]

Contrary to what Lusche seems to advocate this thread

I didn't advocate anything.

[MiloMorai]

During the “Little Blitz” bombing campaign against Britain from January to May 1944 the Luftwaffe bomber force as a whole  suffered almost 60% losses, but only 10% of the HE 177’s were lost.

Wasn't in one of the early raids that 13 He177s were tasked with a mission and only 4 made it to the target area and only 1 dropped its bombs? All the other had to abort due to mechanical troubles.

Jan 21/22
He177 1/KG40 2x2500 kg bombs > 5000kg

Feb24/25
He 177 2/KG100 4x1000kg HE > 4000kg

April18/19
He177 3/KG100 12x 250kg HE > 3000kg

[Lumpy]

I didn't advocate anything.

My mistake. What was the purpose of your post then?