Part I
Okay, here's the problems with the Graff Zeppelin concept.
At the root of the problem is the plain fact that the Kriegsmarine had no naval doctrine that included carriers. Great Britain, Japan, and the US, the major players in the aircraft carrier business, had been operating pure aircraft carriers since the 1920's in case of the later two and, without looking it up, about 1918 for Great Britain. By "pure carrier" I mean carriers whose airplanes are wheeled, are recovered aboard ship by some sort of arrestor arrangement (however primitive in the early years), and could also be operated from land bases. Further, the aircraft in use (again except for the very early models) were specifically designed for carrier operations. The navies of these three nations worked out the problems and challenges of carrier operations in the 20's and 30's and became, each in their own way, the best in the business. The feeble attempts of the Germans (and the Italians) to, first of all, develop aircraft carriers, much less carrier aircraft, were, frankly, laughable in retrospect.
Graf Zeppelin was, in theory, anyway, to have incorporated the best features of IJN, USN and RN carriers (circa 1936, remember), but managed to end up a glopping together of some of the worst carrier ideas that had already been discarded by those services.
All you have to do is look at the main guns and their placement aboard Graf Zeppelin and it's obvious that the Kreigsmarine considered surface vessels as the major threat to their carrier. Imagine, eight 5.9 inch guns in hull mounted barbettes. Probably great for banging away at some British destroyers as they come boiling over the horizon, but since that was a bit unlikely, here was wasted ordnance (read: weight penalty) for no apparent gain. Even pre-war, the RN, IJN, and USN could have told them that that was a waste of time and effort; that the real threat to the ship was in the air. The other eight 5.9 inch guns were to be mounted in twin turrets, fore and aft of the island, not unlike the US Essex class type. There was a problem though. Unlike the dual-purpose 5 inchers on the Essex types (and they were, in the reality of their usage, single purpose AA guns) the Graf Zeppelins 5.9's were not optimized for antiaircraft defense and would have been essentially worthless for that purpose. The USN went down that road with Lexington class and their 8" turrets. By the mid 1930's it was recognized that those guns were so much dead weight. Note that as soon after the Japanese attacked Pearl the 8-inchers were removed and replaced on Saratoga with 5-inch dual purpose and on Lexington with temporary 1.1 in AAA mounts (Lexington was scheduled to receive 5-inch mounts, but she was sunk at Coral Sea before that could happen).
Another major failing in the Graf Zeppelin design was in an incomprehensibly low avgas storage capacity. The smallest and oldest carrier in the IJN, Hosho, had a capacity of 98,000 gallons and carried but 22 planes. Essex class carrier contemporaries of Graf Zeppelin had up to 240,000 gallons avgas capacity and, in practice, were replenished every three to four days during combat operations. And Graf Zeppelin . . . carried a paltry 65,000 gallons. How do you suppose they were planning on replenishing their avgas supply, not to mention their bunker fuel? Yes, yes, I know, the Germans had successfully experimented with underway replenishment, but I'd suggest they never experimented on the scale necessary to maintain carrier operations and especially in the face of some very aggressive enemy carriers looking to put that scalp on their lodge pole. Ideally, one likes to pull off to some out of the way corner of the ocean for such evolutions . . . once Graf Zeppelin hits the Atlantic, there would be no out of the way corners.
Further, how many pilots, crew, and aircraft was Germany prepared to sacrifice to bring their carrier into operational being? Carrier aviation, though somewhat safer today, and "safer" is an extremely subjective term, in the 1930's, 40's and 50's was an extremely dangerous profession. Where were the Germans planning on training their folks to operate their hybrid craft off carriers? In the Baltic? How nice for them, nice enclosed seas with, compared to the reaches of the North Atlantic, nice calm waters. What's going to happen when a pilot who has trained in calm waters is suddenly faced with crappy North Atlantic weather with the horizon a short 5 miles away and a flight deck that rises and falls 25 to 30 feet as he attempts to land. Did the Kreigsmarine have a plan for training LSOs to deal with this problem as they coaxed the pilots aboard? Were there flight deck officers who knew by feel just when to launch a plane so that it doesn't just "thuup" into a wave? News flash, the folks doing these jobs in the USN, RN, and IJN had had a lot of practice at this and even they made mistakes. And what of the poor pilots? Do you suppose their training included flying their craft to their extremes of range; fighting an action; making their way back to where they think their carrier is going to be; if they're lucky, finding it; and then trying to land in the dark on a pitching deck with their engine running on fumes?
The development of carrier aviation in the "big three" over the years pushed operational limits such as these. Leaders in carrier operations knew that conditions would never be perfect and would probably be the worst imaginable. USN fleet exercises in the 1920s and 30's often had admirals such as Reeves and King wondering if they'd ever see their planes again as they were sent off on long missions to attack the make-believe "enemy." Even so, non-combat aircraft losses combined with combat operational losses, i.e., aircraft lost through accident not related to combat damage, but on combat missions, were high.
For example, in the USN, for the entire war, in the course of some 388,000 plus flights (of which 147,000 plus were combat action sorties) there were 4,863 losses of carrier-based aircraft. 1,877 were directly related to in combat losses, either in combat with enemy aircraft or to enemy AAA; 1,001 were combat operational losses; and 1,985 were non- combat related. 61.4% of losses did not result from holes being poked in aircraft or pilots. What do you suppose the rates would be for a single operating aircraft carrier whose entire crew and air group has maybe six months experience in carrier operations? What do you suppose their losses would be like in just achieving that six months of operational training? And for that matter, once in action, how do you suppose this aircraft carrier is supposed to make up it's losses when, to be effective and strike the enemy it must operated outside the range of any land-base re-supply or support?
Making the comparison a little more manageable, looking again at the USN experience, in calendar year 1942, for all carriers in action, in some 6775 flights, including 2559 action sorties there were 155 combat losses, 63 combat related operational losses, and 66 non- combat flight losses.
Statistically, one can take the numbers of carriers in action per month during the period and come up with a composite carrier's operating numbers: Flights: 2755; action sorties 1043; combat losses: 61; combat operational losses: 26; non-combat related losses: 28; for a total of 115 aircraft lost in a 12 month period. For 1942, that means a US carrier, had it been in action for all 12 months, be it Lexington class, Yorktown class, Ranger or Wasp could have experienced aircraft losses in excess of an entire air group. The USN had the means and flexibility to make up such losses with new planes and pilots. How do you suppose a single German aircraft carrier could continue to operate with those kind of losses? What would be their plan for such replenishment? Where would the additional trained carrier pilots come from? Was the German navy aware that the majority of aircraft losses would be from flight deck crack-ups, launch failures, and pilots simply getting lost and never seen again? Somehow, I just don't think so.
The Germans had no tactical doctrine for carrier operations, whereas the RN, IJN, and USN had had twenty years to develop, refine, and hone the same. Actual combat led to the out and out abandonment of some cherished carrier operations doctrinal theories (the concept of deferred departure comes to mind). In the USN, development and adoption of new doctrines (compare the USF-74 of 1941 to USF-74 of 1943 and 1944) went along rather quickly, largely pushed by squadron commanders and pilots who had seen what had worked and what hadn't and were in a position to do something about it by virtue of being responsible for the Fleet doctrine re-writes. [Most of that work was done at ComFAirWest with the officers in charge of training also in charge of the re-writes. I have an original USF-74 fighter section from 1941, the actual rough drafts and notes, including original drawings and sketches, of the 1943-1944 re-writes and a final draft . . . there is a big difference between 1941 and 1944.] The Japanese reacted much slower in changing their doctrine, tactics, and air group composition. The pace of the Japanese change was largely due to organizational inertia and an unwillingness to acknowledge that change was necessary.