[CENTURION]

In my opinion on 17 march 1944 the 366th Fighter Group was in combat with the III./JG2 for two reasons:
1) According to the German sources the aerial combat occurred in the afternoon and indeed the White flight of 390FS was bounced at 15:10.
2) The Americans were attacked near Montfort which - according to the map attached to the MACR of the shot down pilots - seems to match Montfort-l'Amaury (about 40 Km N.E. of Chartres). The two American pilots were last seen in this area and both, evidently, managed to get away before falling (Smith crash-landed 1 mile North of Livarot, near Lisieux, while Hair crashed at Courbepine, four miles north-west of Bernay). Martin probably hit his target (albeit he could not get visual confirmation in the heat of combat) as the III./JG2 lost one Fw190 in aerial combat right northeast of Chartres.

The airport of Chartres was attacked by 361st FG in the afternoon of the 17 march 1944. Fifteen P-47s of the 374th Squadron remained at altitude acting as top cover while the 375th and 376th squadrons carried out the low-level attack. Two enemy aircraft were claimed destroyed on the ground (1 Bf.109 and 1 u/i a/c) along with 4 damaged (1 Ju 88, 2 Bf.109s and 1 u/i a/c). Maj. Merritt spotted a taxiing Bf.109 which he hit repeatedly bringing it to violent halt. According to Merritt's combat report, " after passing over, I observed the (enemy aircraft) ground looping to the left, and the landing gear collapsing as the plane was enveloped in a cloud of dust and smoke ".
In my opinion, it is possible that the aircraft claimed by Maj. Merritt was the Fw.190 of III./JG2 shot down while taking off as, probably, it had already pulled up the wheels off the ground when he was struck (or so the Germans saw as they reported a FW-190 shot down in combat).
Hope this helps.

Best regards.

Marco

Source:
Yellowjackets! The 361st Fighter Group in WW II
Fighter Units Pilotes of the 8th Air Force
Losses of the US 8th and 9th Air Forces
MACR