By the way, here is what is written in the War Diary of the German Naval Staff, Operations Division, September 1942, about air operations against PQ 18 (I have not copied information on U-boats):
13 September 1942
Beginning at 1600, the Air Commander, Lofoten Islands launched an attack on convoy PQ 18 with 28 He 111 torpedo planes, 20 Ju 88 's and 8 He 115 torpedo planes. The Air Commander, North dispatched an additional 18 torpedo planes and 17 bombers. The Air Force reported as definitely sunk today 9 merchant vessels totalling 61,000 GRT, as probably sunk 1 tanker and 5 merchant vessels with 48,000 GRT, as damaged 10 or 12 steamers with a total 90,000 GRT, conceding the possibility of duplications.
14 September 1942
The Air Commander, Lofoten Islands dispatched 36 torpedo planes and 18 bombers against convoy PQ 18 after 1530. The 5th Air Force reports today's result as 6 steamers and 1 tanker with a total of 49,000 GRT sunk, as well as 1 destroyer. In addition, 3 steamers of 21,000 GRT were damaged and a destroyer probably damaged. The aircraft carrier may have been hit by 3 aerial torpedoes; columns of water were observed. However, no confirmation of any damage has been received as yet. The convoy was last sighted at 1900 on a southerly course and consisted at that time of 28 merchant vessels.
15 September 1942
The Air Force had no particular success today either. The majority of the planes did not find the target due to bad weather. Direction finder equipment wes affected by strong aurora borealis and was partly not audible at all. The last location report after midnight counted approximately 30 merchant vessels, 1 carrier and 18 escort vessels.
The weather favors the enemy and saved him from suffering losses similar to those on 13 and 14 Sep.; it permitted the enemy to escape the range of our bombers without deviating very far north and to gain time by staying on his course
16 September 1942
Planes lost contact around noon, after having reported at 1120 that convoy PQ 18 consisted of approximately 31 merchant vessels, 1 aircraft carrier, 1 heavy cruiser, 13 destroyers and 8 escort vessels.
On account of bad weather the Air Force did not attack.
17 September 1942
Reconnaissance planes reported PQ 18 at 0950 In quadrant AT 7117 consisting of approximately 30 merchant vessels on a course of l00°, without the aircraft carrier which evidently had been shifted to convoy QP II4.. At 1551 submarine U "251" sighted 3 destroyers and ship-borne planes, probably belonging to the carrier, in quadrant AC 3568. Neither submarines nor aircraft were able to close In for attack on either convoy.
18 September 1942
Tne Air Force reported convoy PQ 18 at tne White Sea entrance at 1000. Tne 5th Air Force reported sinking 6 merchant vessels aggregating 46,000 GRT and 1 escort vessel; procably 6unk were a mercnant ships totalling 15,000 GRT. 5 merchant snips and 1 destroyer were damaged. Prior to tne attacks the oonvoy consisted of between 49 and 53 ships; following the attacks there re-air^ed 40 to 43 ships including escort and patrol vessels, about whicn detailed information could not be obtained due to bad weather.
19 September 1942
Air reconnaissance sighted convoy PQ 18 at 1530 at the northeastern entrance of Dvina Bay. It is expected to reach Archangel around 2230. Final reports about the number of ships still in the convoy have not yet been received, or have not yet been evaluated.
On the basis of reports from the 5th Air Force received by the Naval Staff between 13 and 19 Sep. 1942, the Air Force definitely sank 16 and probably 6 merchant vessels on 13 and 14. Sep., and sank 6 and probably 2 on l8 Sep. According to this a total of 26 merchant vessels were sunk definitely and 9 probably, out of the convoy which was estimated by the Air Commander, Lofoten Islands on 13 Sep. as consisting of 45 merchant vessels. However, on 17 Sep. convoy PQ 18 was repeatedly reported as proceeding in close formation consisting of 30 merchant vessels. It remains to be seen what the final report of the Air Force will be after a final check of its reported successes.
You will notice that the number of involved aicraft is given for the 13th and 14th, but not for the 18th.
Also note the critical eye of the Kriegsmarine on the Luftwaffe sinking claims. Well the latter seriously overclaimed on Sep 14 and 18.