BenDover states:
"1. The ostie is open toped. That means the gunery crew and turret equipment is fully exposed to aircraft. Hell a rock thrown at the right angle could literaly knock out a crew member in the turret.
2. It's been fixed, even hazookas have a difficult time penetrating the armour.
2b. A track could be thrown out if a bullet knocked a pin out of place"
I know the Ostwind is an open topped turret AA veh. I probably know more about the Ostwind and it's brothers the Mobelwagen & Wirbelwind than enyone in here.
I'll agree, the crew is somewhat exposed, but rounds have to be fired at an angle to strike the crew. It is, of course possable to hit the gun barrel at certain angles which in turn might damage it.
Tracks being takin' out by a .50cal or .303 round is stretching it a bit. This typically did not happen in WWII.
The biggest threat to this type of veh was other tanks, ATG's and bombs/rockets. Also the reloading crew was extremely vulnerable to small to medium arms fire.
Piece of info:
Wirbelwind and Ostwind were successors to the Flakpanzer IV Mobelwagen (armed with 37mm Flak 43 L/89) - "interim solution" produced before the introduction of real Flakpanzer. In July of 1944, prototype of Ostwind (Eastwind) - an air defense armored vehicle build on Panzer IV's proven chassis was produced. Its design was very similar to that of Flakpanzer IV Wirbelwind (Whirlwind) which prototype was build in May of 1944 and was to become the first true Flakpanzer. Both vehicles were build on retired or battle damaged Panzer IV (mainly Ausf F/G) chassis/components returned from the front for major repairs. The concept of Wirbelwind was that of Karl Wilhelm Krause, an officer of 12th SS Panzer Division "Hitler Jugend", who in summer of 1944, proposed to mount four barrelled 20mm Flak 38 L/112.5 gun on PzKpfw IV's chassis.
Wirbelwind and Ostwind were fitted with very similar (especially designed) open-top (Wirbelwind's turret had 9 side panels and Ostwind's had 6 side panels) turrets mounted in the place of standard turrets. Ostwind's turret was nicknamed Keksdose - cookie tin. Main difference was that Wirbelwind was armed with quadruple 20mm Flak 38 L/112.5 guns while Ostwind was armed with single 37mm Flak 43 L/89 gun (both could be used against ground targets as well). 20mm Flak proved to be less effective than 37mm Flak and was eventually replaced by it. Both were produced by Ostbau Works in Sagan, Silesia in limited numbers due to the material shortages and the fact that Ostbau Works moved to facilities of Deutsche Eisenwerke in Teplitz and Duisburg due to danger of being overrun by the Soviets. Overall from May to November of 1944, only 87(105) Wirbelwinds were made, contrary to only 44(43) Ostwinds produced from July 1944 to March of 1945. Both vehicles were issued to Flugabwehrzug (AA platoons) units of Panzer Divisions. There were never enough of them to equip frontline units, which were in the need for adequate mobile AA defense. Both proved to be very effective against low flying aircraft. The interesting fact is that prototype Ostwindwas combat tested by 1st Waffen SS Panzer Division "Leibstandarte SS Adolf Hitler" during the Ardennes Offensive (December 16 to 22 of 1944) and returned to factory undamaged
