B-17 vs Avro Lancaster

[Logan Hartke]

I bet that was a sight.  I got to see the Lanc in flight at the 2009 Thunder Over Michigan airshow in loose formation with a Hurricane, some Spits, and a Mustang.  The sound of all those Merlins was music to my ears.  I agree completely that the Lanc is the better sounding airplane.  Lovely.

I've seen B-17s in flight a number of times, but the most memorable for me was when we had the Collings Foundation B-17 and B-24 come in and land at the little Amelia Island airport to give rides.  I was surprised at how quickly the B-17 could get off the deck.  The thing that I loved the most, though, was seeing the B-17 come in for landings (since they were going up and down the whole time).  It was hard not to think of "Twelve O'Clock High" and "Memphis Belle" when you saw the silhouette of it coming in.  Just so iconic.

Cheers,

Logan

[jcf]

The Collings B-17 Nine-O-Nine sounds even better from the inside. 

[kitnut617]

A B-17 and a CASA 2.111 (Spanish built Heinkel 111 with Merlins) visited Calgary some years ago, $10 got me a 'walk-about' around them, inside and out.  No flying though ---    

[Logan Hartke]

The Collings B-17 Nine-O-Nine sounds even better from the inside. 

Aww, not cool. 

Cheers,

Logan

[Captain Canada]

That would be awesome to see....whether getting a ride or not. Watching aeroplanes take off and alight is always the best part !

[KJ_Lesnick]

Captain Canada

The Orenda jet powered Lancs used to wreak havoc on NYANG guard units.

There were Lancasters fitted with jet-engines?  I didn't know that...

Then there's the story of the B-17 that caught and passed a Lanc....until the Lanc pilot throttled up and returned the favour including a victory roll !

So, it was faster overall?  That makes some sense when you consider the different engine types and all that.



Logan Hartke

I've heard some pretty impressive stories about the B-17's maneuverability, especially in some of the smaller-scale encounters against the Japanese.

Really?

My personal view is that the Lancaster was the better bomber.  When it came to carrying X number of Y pound bombs Z miles, the Lancaster was the better aircraft for the job.  Since that's the primary role of the bomber, I think that makes it the better of the two.  The Lancaster could perform missions that no B-17 ever could.

Correct

Now, that having been said, you really can't go wrong with the B-17.  It had greater defensive firepower, greater survivability, and a very respectable range.  More often than any other plane from World War Two, I've heard veterans say about the B-17, "she'd bring you home."

Yeah, the survivability aspect was the thing that made the difference.  If I recall it was easier to evacuate...

There's a couple other things to consider.  The Boeing B-17 first flew six years before the Avro Lancaster.  Let me put that in perspective.  The first flight of the B-17 took place BEFORE the Seversky P-35.  The Avro Lancaster first flew AFTER the P-51 Mustang.  The B-17 first flew BEFORE Guernica.  The Lancaster first flew AFTER the Blitz.  That's how big of a generational gap we're talking about.

That's true, we seemed to build some serious heavies before the RAF did unless you count the V-1500...

The B-17 was originally designed when the USAAC quite frankly didn't know what it wanted.

I thought they pretty much had a basic idea in mind...

Avro aircraft hold many "firsts" from the history of aerial combat, including one of the first successful bombing raids on an enemy installation behind the front lines (the Friedrichshafen raid).

I thought the first behind the lines raids was in WW1... they weren't as big as the ones of WW2 but they happened from what I remember...

They knew what they wanted and what they needed.

So the baseline Lancaster was less modified than the first B-17... that makes sense.

The Model 299 prototype had about as much in common with the B-17G as the Manchester did with the Lincoln.

Yeah, they had different engines, a different tailfin and tailcone, no powered turrets, no tailgun, blistered gun-installations instead of door-gunners, little to no armor, no self-sealing tanks, and more.

The B-17 had to go through at least five iterations before it was really combat-ready (the B-17E), and another two before it was "good" (the B-17G).

Yeah, the B-17E was the first to have a tail-gun; it had a redesigned tail, and might have been the first to have a powered top & bottom turret.  The B-17F included the provision for greater bomb-loads (ironically the bay seemed have the volume to store all the bombs, but not the means to deliver them) and the -G had the powered chin-turret which better warded off attacks from the front.

The Lancaster B Is, however, were still a very good bomber in 1945.

Yes, and far as I know they were probably used heavily...

Also, the Lancaster had more horsepower available to it.  The B-17 had four R-1820s, which powered aircraft such as the DC-2, Polikarpov I-16, Dauntless, and Wildcat.  The Lancaster had four Merlins, which powered the likes of the Hurricane, Spitfire, Mosquito, and P-51 Mustang.  I can tell you which engine I'd rather have for my bomber given the choice.  The aircraft with four Merlins had better carry a greater bomb load!

That's what puzzled me about the speed issue... admittedly doing some extensive checking some of the Lancasters could do around 318 mph with the newer merlins.  One managed to do Mach 0.70+ in a dive.  Part of me wonders if they were using TAS or IAS for speed measurements as it would explain some things.

The Boeing designers that came up with the Model 299 knew what they were doing.  It was a modern, sleek, adaptable, sturdy design.  Look at pictures of the Y1B-17s.  The wing, engines, cockpit, landing gear, and even fuselage contours look much as they would on the B-17G.

It had the basic look.  But it was no B-17E/F/G...

The Flying Fortress moniker wasn't just advertising, either.  Attacking a B-17 bomber box was not for the faint of heart.

No, it was a beast for an enemy to face off against, especially when they were put into formations which allowed them all to cover each other.  Often going in got one riddled with holes...

The Lancaster's lack of a ball-turret, by comparison, made the Lancaster vulnerable to Schräge Musik equipped German night fighters for the entire war.  In fact, this significant blind spot meant that it was months before Bomber Command even realized why they were suddenly losing so many bombers.

The irony was the plane could carry a bottom turret, but they simply chose not to.  I'm not sure why though I have a hunch drag/range might have played a role.  Later on the radome often sat there instead of a gun.  

As for them not even realizing why planes were dropping left and right one reason that played a big role in addition to element of surprise was that they flew at night... you can't see so good in the dark.

When it comes right down to it, though, if you asked me if I'd rather have 1,000 Lancasters bomb a target or 1,000 B-17s, I'd pick the Lancasters, no question.  More tonnage, more damage.  If you asked me if I'd rather be a crewman on a Lancaster or a B-17, I'd pick the B-17, no question.

Actually, I'd have picked the B-17 most of the time.  I want the planes to not just carry the bombs; I want them to deliver them.  That's why I tend to have favored the Mosquito over the Lancaster or B-17 for that matter.

I was surprised at how quickly the B-17 could get off the deck.

Well most large aircraft in those days could takeoff in much shorter distances due to the fact that they were designed to fly at lower speeds.


Albeback

Each aeroplane should surely be judged on its own merits. Both had their good points and their bad points.

That's sort of what this thread was about...

There has been a lot of (possibly) ill informed criticism of the allegedly poor defensive armament fitted to the British heavies.

Well the problem was that the Germans seemed to have armored their fighters meaning you had to hit the engine, radiator, cockpit, possibly control surfaces to bring them down.

David was keen to point out that experience showed most engagements at night took place at very short ranges - apparently only 200 yards or less.

I didn't really think about it much before but it does make sense that you'd shoot closer as you can't see as well in the dark.  This would probably be the same for the enemy as well as they'd use their radar to get to the target, then use visual aiming.

It was his honest view that 4 x .303 Brownings in a rear turret firing a total of 80 rounds per second could really ruin ANYBODY's day at that distance!

Well .303's are the kind of rifle rounds one would use to shoot people with.  However, truthfully the 12.7mm would have been a better choice IMHO, not necessarily for superior range, but to cause more damage quicker.

I have seen it quoted by a historian ( I forget who) that basically,the Americans sacrificed bomb load for defensive armament because they tried to fight through the defences rather than avoid them.

Actually both the RAF and USAAC/F believed they could just blow through enemy air defenses with self-defending armament.  The problem was that the RAF's planes weren't armored well enough or defended well enough; they also couldn't fly as high or fast as the B-17's.  Therefore, they decided to use the cover of dark to allow them to slip through.

Neither service either believed in using fighters to escort bombers, or could not come up with a way to build one that was too expensive for their tastes.  Once we had effective long-ranged fighters, things rapidly changed.

The alleged super accuracy of the American Norden bomb sight  appears to have been somewhat over stated. My understanding is that while the sight itself WAS very accurate, if you have (say) 800 B-17s (covering several square miles of sky)  all dropping their bombs together then, by definition, they will obliterate everything within the target area anyway (hopefully including the actual target!). So was it not really just daylight carpet bombing after all?

Well, the issue was several factors

• Accuracy of the bombsight itself to factor in variables such as speed, altitude, bomb-ballistics, known drift: Pretty good, though the Mk.XIV the RAF used below 20,000 feet wasn't much less accurate truthfully; above 20,000 feet however, the Norden reigned "supreme" which is to say it was not horrendous. Regardless, one must have...
  
• Visibility: One has to see the target to accurately hit it.  If the weather is clear, you're set. In Europe, the skies could be cloudy often, and when there were lots of clouds, you couldn't see the target!  Hopefully you'd find some holes in the clouds to find something you can recognize, then guesstimate the bullseye from there and wait for the bombsight's crosshairs to pass over that estimated point.  Even if that works out there's...
  
• The miles of air between the plane and the ground: While drift can be factored in to some degree, the fact is that sometimes the air can be smooth where the plane is, smooth on the ground, yet rough in between.  Since they weren't able to see all the air in between, they based their estimates either on the airflow they were experiencing; or if over certain types of surface (seas for example you can see the currents and gauge a drift from that), and bombs away.
  
• Bomber Formation: The biggest issue here is the width of the formation as the bombsights are probabilistic, and measured in CEP.  This is the imaginary radius in which 50% of the bombs will land.  If this CEP is 55 feet, 50% of the bombs will fall in a diameter of 110 x 110; if 400 feet (average); they'll land in a zone of 800 x 800 feet.  So, if you have several bombers side by side with some spacing between them this rapidly reduces the CEP to seriously terrible proportions.  The easiest example would be to walk over your carpet and hold a flashlight down to the floor and you get an area that's lit up by the light.  Now imagine each spot being an area of 800 x 800 feet and the light emitter as a bomber; now imagine three side by side, then another three on either side of that (that was our typical combat box: three in the front mid-level in a V; another three on either side also in a V with one above and below the middle set, and a third V located in the back and slightly below the lead).  While there may be overlaps, there's going to be lots of area that's going to be "covered" and "lit up".  You'd instinctively think that they'd all be aiming at the exact same point, and thus would all converge into a mid-air; fortunately I don't know if that ever happened as the USAAF flew generally in day.  I assume they offset a bit depending on their location in the formation.  While early on the idea was for every plane to be using it's own bombardier to accurately aim, but considering the skill of the bombardiers varied, the USAAF started to play with the idea of a...
  
• Toggeleer:  Essentially all the planes had a guy who dropped the bombs, but only one was a bombardier who sat in the lead airplane.  He was the best of the bombardiers, and he used his norden to sight the target; all the other bombardiers were toggleers and did what he did; when he opened the bay doors, they opened their bay-doors; when he released, all the rest dropped their bombs too.  To a point it actually works because it takes a certain period of time to see something, understand what it is, then react to it and move your body (your hands in this case) to react (interestingly this is one reason why in cars you're supposed to be a certain number of seconds behind somebody, part of it is reflex time, the rest is response time for the car).  Essentially all the planes in theory open their bay-doors over the same spot in time and space; they all release over roughly the same point in time and space (length wise at least).  It seems brilliant unless the formation gets exceedingly long: Early on we used fairly small formations, and then we got them bigger.  Soon they reached 60, 90, or more.  The longer the formation the more distance there is between the lead aircraft and the last plane.  If they all released at the same time many bombs would land really really far short.  I don't know if this issue was addressed, though I supposed if you had a few bombardiers spaced down the length of the formation with the rest being toggleers, it could work.  Otherwise as I described, it'd be doomed to fail.
  
• The bomb-fins: Some bombs had a surprisingly high rate of fin failure.  The bomb-sight predicts based on the ballistic quality of the bomb, which is determined by it's shape and mass: If the shape changes in flight, even if the prediction was "right", the result is "wrong" and the bomb does not go where it should... you don't need to have structural failures causing bomb-accuracy issues, sometimes the issue is psychological, such as...
  
• Bomb Creep: It seemed inexplicable, bombers were dropping their bombs short, and what was funnier was each one landed shorter than the one before it.  Eventually it made sense -- the crews were flying through wave after wave of fighters, and then during the bomb-run they'd have to fly straight and then would be pounded by flak.  You'd have explosions going off all around you and you'd have to be a bit nuts to not be scared... some people get scared more than others and would release their bombs a little bit early; the next bombers would release early as well and it just got worse and worse.  I don't know if the USAAF did this, but the RAF would just set the initial aiming point ahead of the actual target figuring that if they did land short eventually something would get plastered.  Keep in mind they weren't as concerned about accuracy
  

.

I simply cannot get round how these men willingly climbed into their aircraft day after day despite knowing the terrible odds they would face.

I think they generally felt it was necessary or it had to be done.

Perhaps the only real precision bombing was carried out by 9 & 617 squadrons using the SABS bombsight and 12,000lb Tallboy bombs?

The RAF used the Mosquitos for some missions that were even more ballsy than that... including this raid that involved blowing out the side of a prison wall; the USAAF did a variety of missions using their A-20, A-26, B-25 and so on that were precise probably.  

Admittedly the ability to employ a 12,000 and 22,000 pound earthquake bomb was outside the B-17's capacity; the SABS though was similar to the Norden.  I'm not sure how it compared exactly, but it may have been more accurate in a few ways (predicting supersonic ballistics), but it seemed a little less accurate at its best.


Kitnut617

Robyn / Kendra, had another thread going a while ago where she was asking the same questions to comparing a B-17 to a Lanc.  It ran for quite a few pages and as far as I could see, the answers weren't going they way she expected (my opinion - I had posted a number of photos on it and other things).  Then the whole thread just disappeared ---

If I recall, the topic had to do with collecting information for a WHIF design.  A member then kept dragging the topic off-course from what I wanted it to and despite my efforts to get it back on track, he kept dragging it off course.  I got sick and tired of it and deleted the thread since I realized it was at my disposal.  

I figured I could delete the thread, then bring the thread back later.

[Logan Hartke]

Avro aircraft hold many "firsts" from the history of aerial combat, including one of the first successful bombing raids on an enemy installation behind the front lines (the Friedrichshafen raid).

I thought the first behind the lines raids was in WW1... they weren't as big as the ones of WW2 but they happened from what I remember...

That was WWI.

http://www.ospreypublishing.com/store/The-Zeppelin-Base-Raids-%E2%80%93-%20Germany-1914_9781849082433



Cheers,

Logan

[KJ_Lesnick]

That was WWI.

Wow, and that appeared to be dive-bombing too...

[Captain Canada]

Orenda tested their early turbos on borrowed RCAF Lancs.

As for the story, they saw the B-17 coming, so throttled back to let him catch up, then poured on the coals and passed him. No idea if the Fort was going full bore or just cruising, but it's still a good story ! ( if you're in the Lanc camp )

[wuzak]

Then there's the story of the B-17 that caught and passed a Lanc....until the Lanc pilot throttled up and returned the favour including a victory roll !

So, it was faster overall?  That makes some sense when you consider the different engine types and all that.

The Lanc was no faster than a B-17. Well, at least a regular Lanc. A B-17G could do ~300mph with War Emergency Power. Many books quote 287mph. A regular Lanc would be in the region of 280-290mph flat stick.

Also, the Lancaster had more horsepower available to it.  The B-17 had four R-1820s, which powered aircraft such as the DC-2, Polikarpov I-16, Dauntless, and Wildcat.  The Lancaster had four Merlins, which powered the likes of the Hurricane, Spitfire, Mosquito, and P-51 Mustang.  I can tell you which engine I'd rather have for my bomber given the choice.  The aircraft with four Merlins had better carry a greater bomb load!

That's what puzzled me about the speed issue... admittedly doing some extensive checking some of the Lancasters could do around 318 mph with the newer merlins.  One managed to do Mach 0.70+ in a dive.  Part of me wonders if they were using TAS or IAS for speed measurements as it would explain some things.

The Lancaster had more power at take-off than the B-17 (~1600hp for later versiosn vs ~1200-1350hp). However, the Lancaster used single stage Merlins (mostly), so their altitude performance was lower than the take-off performance. The B-17 coupled its R-1820s with turbos, which maintained the engine ratings to as much as 30,000ft. The ceiling for a Lancaster was less than 25,000ft, from memory, while B-17s regularly operated above that.

There were some Lancasters built with 80-series 2 stage Merlins. These improved the ceiling and top speed (around that 318mph mark you mention KJ), but only a handful were built.

I think that the B-17 was slightly more aerodynamically efficient. At least up until the -F.

• Bomb Creep: It seemed inexplicable, bombers were dropping their bombs short, and what was funnier was each one landed shorter than the one before it.  Eventually it made sense -- the crews were flying through wave after wave of fighters, and then during the bomb-run they'd have to fly straight and then would be pounded by flak.  You'd have explosions going off all around you and you'd have to be a bit nuts to not be scared... some people get scared more than others and would release their bombs a little bit early; the next bombers would release early as well and it just got worse and worse.  I don't know if the USAAF did this, but the RAF would just set the initial aiming point ahead of the actual target figuring that if they did land short eventually something would get plastered.  Keep in mind they weren't as concerned about accuracy
  

Bomb creep was often caused by the smoke from the bombs obscuring the target, following bomb aimers losing the target and dropping their bombs early. The RAF developed a master bomber system whereby the master bomber would observe the bombing and apply corrections to the aim, would advise crews as to which of several markers are positioned well and should be used and which are poorly located and should be ignore and would call for additional marking if the original markers had gone out or had become obscured.

This was easier for the RAF to do since bombers still aimed individually, unlike the USAAF.

It was his honest view that 4 x .303 Brownings in a rear turret firing a total of 80 rounds per second could really ruin ANYBODY's day at that distance!

Well .303's are the kind of rifle rounds one would use to shoot people with.  However, truthfully the 12.7mm would have been a better choice IMHO, not necessarily for superior range, but to cause more damage quicker.

Some Lancs had their rear turrets modified with twin 0.50" mgs instead of the 4 x 0.303"s.

[wuzak]

Perhaps the only real precision bombing was carried out by 9 & 617 squadrons using the SABS bombsight and 12,000lb Tallboy bombs?

The RAF used the Mosquitos for some missions that were even more ballsy than that... including this raid that involved blowing out the side of a prison wall; the USAAF did a variety of missions using their A-20, A-26, B-25 and so on that were precise probably.  

Admittedly the ability to employ a 12,000 and 22,000 pound earthquake bomb was outside the B-17's capacity; the SABS though was similar to the Norden.  I'm not sure how it compared exactly, but it may have been more accurate in a few ways (predicting supersonic ballistics), but it seemed a little less accurate at its best.

I would say that the Dams raids were precision bombing raids, and some of the bomb aimers used nothing more than a piece of string and the window frame....

The Norden has a spectacular reputation, but it did have its downsides - one of which was the requirement to maintain a straight and level course for some time - not sure how long exactly, but it may have been a minute or more.

The regular British Mk XIV bomb sight needed only 10s of level flight prior to the drop, allowing the crew much more flexibility in manoeuvring.

It appears that only 617 Squadron used the SABS - 9 Squadron, who also dropped Tallboys, used the Mk XIV.

[PR19_Kit]

Perhaps the Manchester should be considered as a 'Mk 1 Lancaster' from the point of view of development dates and first flights etc? The basic structure and aerodynamics of the Lanc came directly from the Manchester and the Merlin engines were the primary change in the design.

[Logan Hartke]

I don't think that's too far off.  As I said in my original post, "The Model 299 prototype had about as much in common with the B-17G as the Manchester did with the Lincoln."

Cheers,

Logan

[jcf]

The Collings B-17 Nine-O-Nine sounds even better from the inside. 

Aww, not cool. 

Cheers,

Logan

No, it was hella cool. 




My favourite pic.



Geez, it was eleven years ago. Wish I'd owned a better camera at the time.

[jcf]

The root question is the equivalent of 'which ice cream is better?'
It is extremely subjective and so full of variables that a singular
answer is impossible.

The most important thing is the Allies had both, in large numbers, and
the Axis didn't.

What I find most interesting is that both four-engine aircraft resulted
from official requirements for twin-engined types. Perhaps a telling
case of the aeronautical folks having a better grasp of the realities
of the contemporary technology than their customers.