MESSERSCHMITT Bf 109 DROP TANK FUEL CAP

Whilst the Messerschmitt Bf109 was arguably one of the most widely operated and iconic aircraft of WWII, its small streamlined frame and stubby wings provided little room for a sizeable fuel tank, rendering it relatively ineffective as a long range patrol and bomber protection aircraft.

In fact, during the lead up to and during the Battle of Britain, the Luftwaffe's bomber command suffered horrendous losses with their primary bomber support fighter the Bf109 having less than nine minutes of fuel available for fighter protection over the British mainland targets.

This led to the twin-engined Messerschmitt Bf110 being forced to provide the bulk of bomber protection but this also made the high speed fighter/bomber equably vulnerable to British fighters due to it having to reduce speeds to maintain cover for the lumbering Luftwaffe bombers. 

The solution to the Bf109’s lack of range was a simple one and in the end, two 300lt aluminium drop tanks were fitted below either wing or a single drop tank carried directly below the pilot.

Fully loaded the Bf109 was extremely heavy with speed and climbing significantly compromised but using a tactics later adopted by the USAAF P51 Mustangs, the 109’s flew forward and high above the main bomber fleet and once their external tanks were jettisoned, used their superior dive speed to fall on the British fighters attacking the bombers below.

With the later introduction of the high performance Focke-Wulf Fw190, they too were fitted with the ability to carry the same 300lt drop tanks which like the Bf109, greatly extended their operational range. 

Manufactured by the German Deutche Benzin-Uhrin (DBU Works), the central Cap cast markings read 'KRASTSTOFF' or 'FUEL' with the wording 'Beluftungsventil' or Ventilation Valve' in raised text around the cap at the base.

Made from an Electron magnesium, the DBU works produced two types of Fuel Caps, vented and unvented but used the same casting for each as indicated by the common part number 8-4520A cast into the reverse of the small attachment screw arm.

Primary aircraft fuel tanks on both the Bf109 and the Focke-Wulf Fw190 required a ventilated fuel cap, so five small holes were drilled into the middle of the casting and a small spring loaded padded washer pressed into the recessed housing beneath. 

Even though labeled as 'ventilated', fuel caps without the hole and valve modification had no ventilation and were installed at the top of the 300lt aluminium drop tanks carried by both the Bf109 and the Focke-Wulf Fw190. This was changed in later versions of the
Bf 109 however, when an in-line ventilation outlet valve was installed enabling the 'sealed' DBU cap to be used on both primary and drop tanks. 

Secured by two 8mm studs which were screwed down over the cap's arm cutouts, drop tanks required air pressurisation to transfer the fuel up into the aircraft system and so, they featured the 'sealed' cap version as seen here.

Mounted on its 100 yr old Mango Wood stand with a highly detailed hand crafted and airbrushed model of the iconic German fighter the Messerschmitt Bf109 and informative Fact Sheet, this would make an extraordinary and highly valued, original memento of Luftwaffe air power for any aviation enthusiast.




This Bf109 collectable comes complete with detailed 1/72 or larger 1/48 Scale Model, Mango Wood Stand & Plaque plus Printed Fact Sheet featuring photo of collectable on aircraft.

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