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  • Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.

    Post 16 Update

    Post 17 Warning

Douglas B-18A "Bolo"; Cowl Flaps?

PutPut

PutPut

Charter Member 2014
I am making good progress on a FSX native version of the B-18A. The question is whether it has cowl flaps. The drawings I have and none of the photo's I have show them. Some of the references I have state that it did have them but don't show them in their photo's. It was based on the DC-2 which did not have cowl flaps. If anyone has any definitive information on this subject please post it here.

Thanks, Paul
 
Paul,

I am highly confident in thinking that the original production variants did not (just like the earliest B-17's did not have cowl flaps either).

You may find a re-engined/upgraded/non-standard example, such as this one, with cowl flaps, but the original design/original powerplants/cowlings didn't seem to have them. I'm really looking forward to seeing your work on this one, Paul!

5643569074_435e126ef2_b.jpg


The USAF Museum's amazing example (original powerplants/original cowlings):

071030-F-1234S-027.jpg


A farily stock/original B-18 on the early civil register (original powerplants/cowlings).

5643001023_2bdf1ff49a_b.jpg


And I'm sure you've seen this photo by now - I'm always amazed by the clarity/color (it might as well have been taken yesterday).

1c40cce49a5a824d_large.jpg
 
After trawling through more images, some of the original models must have had different powerplants from one another, as these do clearly have cowl flaps. It must be a difference between production models (with different cowlings for different powerplants?).

B-18_close.jpg


B182039-59320d2.jpg
 
Here's a close-up of one of the non cowl-flap cowlings (as far as I can see). There is also a difference in nacelle designs,at least over the top, between those with cowlings that don't have cowl flaps and those that do (i.e., the examples without cowl flaps, have the exhaust piped back over the top of the nacelle, in a very long pipe, where as those with the cowl flap cowls, and likely different engines, have a short exhaust pipe out the side of the nacelle, and an inlet on top of the cowling).

b-18_bolo_09_of_23.jpg
 
And just because of the project at hand, and I'm sure you have already seen it, but here is an excellent overview of the cockpit on the B-18 at the USAF Museum (when saved, or viewed in another tab, it is quite a large photo).

060906-F-1234S-001.jpg
 
I think you are right, I suspect some were re-engined and given cowl flaps when they were assigned to anti-sub duty after the start of the war. My intent is to do the bare metal production version without cowl flaps. The shot from Life Mag is a favorite of mine; I just wish I could get rivets to look like that! The B-18A is the first real warbird I ever saw in real life. I was 8 years old in 1940 when a B-18A and a AT-6 came to our local field in Dubuque, Iowa on a recruiting gig.

Thanks, Paul
 
Bomber_12th said:
Here's a close-up of one of the non cowl-flap cowlings (as far as I can see). There is also a difference in nacelle designs,at least over the top, between those with cowlings that don't have cowl flaps and those that do (i.e., the examples without cowl flaps, have the exhaust piped back over the top of the nacelle, in a very long pipe, where as those with the cowl flap cowls, and likely different engines, have a short exhaust pipe out the side of the nacelle, and an inlet on top of the cowling).

b-18_bolo_09_of_23.jpg
Click to expand...

looks a bit like it has a cowl flap along the top, or at least summing hinged ... did they change it from just haveing 2/4 at the top to haveing them all around later on??
 
Put Put, I really luv the quirky planes you come up with to make. But by golly, I have to say that the B-18 is one ugly aeroplane. :)
 
The latter Bolos and Digbys (RCAF) had basicly C-47 QCU's from the firewall forward. Looking forward to her, Paul.
 
Paul, I hope you will consider making that pop-up gun turret an animated feature on your FSX version. :)
 
Joe Baugher has the clearest text description I found that should clarify some of the points:

[SIZE=+1]The DB-1 made its first flight in April of 1935, powered by a pair of 850 hp Wright R-1820-G5 air-cooled radials.

"Production B-18s were powered by a pair of 930 hp Wright R-1820-45 radials housed in revised cowlings. The nose cone was somewhat shorter than that of the DB-1 prototype, and it contained more lateral windows as well as a bomb-aiming window in its forward lower portion. With full military equipment fitted, the performance of the production B-18 fell off slightly, to a maximum speed of 217 mph, cruising speed of 167 mph, and combat range of 850 miles. Nevertheless, the B-18 was the most modern bomber design then available to the Army.

The first production B-18 was delivered to Wright Field on February 23, 1937. The DB-1 prototype was brought up to full B-18 standards and was redelivered to the Army five days later as serial number 37-51.
[/SIZE][SIZE=+1]
The second (and last) major production version of the Douglas bomber was the B-18A. The B-18A differed from the B-18 in having the bomb-aimer's position moved upward and forward underneath an extended glazed housing, while the flexible forward-firing nose gun was moved further back and below and was mounted inside a globular ball turret. This led to the rather unusual geometry in which the bombardier sat above and ahead of the nose gunner. A transparent domed cap was added to round off the top of the dorsal turret, so that it no longer lay flush with the fuselage when retracted. The B-18A was powered by two 1000-hp Wright R-1820-53 radials driving fully-feathering propellers. "
[/SIZE]

From there it gets really muddy. The best photos I can find of the early versions show the prototype XB-18 with DC-2-style smooth cowls View attachment 52674
B-18 -smooth cowls with an 'eyebrow' View attachment 52679 -- then a B-18 but with overwing exhaust http://www.aero-web.org/specs/douglas/b-18.htm

and a Douglas photo of a B-18A with the overwing exhaust (no apparent cowl flaps) View attachment 52675

One curious (deceptive?) one is of a B-18A in Alaska - Overwing exhaust, eyebrow cowl, but note what appears to be a flared cowl or open cowlflap on the outboard side of the starboard nacelle:
http://vilda.alaska.edu/cdm4/result...OSEARCHALL&CISOROOT=all&CISOBOX1=ASL-P343-566

The various museum aircraft and their descriptions are not consistent. There's the Castle museum a/c that is listed as a B-18B but has a B-18 nose and turret; the McChord museum B-18A with cowl-flap, low exhaust engines (with the 'eyebrow cowl') http://www.prop-liners.com/b183.htm and an early pic of the Pima B-18B with similar engines. I am beginning to suspect that these latter cowls are a result of post-war civilian mods to DC-3 Wright engines and cowls for cost/commonality reasons.

To confuse the issue more, the Pima aircraft when restored as the B-18B anti-sub aircraft, exhibits the overwing exhaust:
as first displayed, http://www.flickr.com/photos/jackmcgo210/3234716001/in/set-72157612654153984/
and as restored http://www.harpoondatabases.com/Encyclopedia/Entry2975.aspx

Don't you love a puzzle? The best-guess I can make is that the overwing exhaust (likely with no cowl flaps) came in part-way through the B-18 production and was carried through to the -18A as most of the late-war and Digby pics are of this style

Don't know if you've seen these pics of a Digby being dragged out of the water: http://www.flickr.com/photos/robbie1/1912244/in/set-48496/ which also give an idea of one Digby paint scheme.

Speaking of which, found this pic of a "full" B-18B with the MAD boom View attachment 52681 and I was surprised to find some good pictures of the only DB-2
[SIZE=+1]
The DB-2 was a B-18 airframe fitted in March 1937 with a power-driven nose turret with an extensively-glazed large bombardier's enclosure. It bore the serial number 37-34, which identified it as the last aircraft ordered on the original B-18 contract. However, it was delivered out of sequence, and it was actually the 36th B-18 to be delivered when it was received at Wright Field on November 8, 1937. This modified nose did not prove satisfactory, and the aircraft was eventually converted back to standard B-18 configuration before being delivered to the 18th Reconnaissance Squadron at Mitchel Field, New York.
[/SIZE]http://www.militaryfactory.com/imageviewer/ac/gallery-ac.asp?aircraft_id=717 (photos 14-16)

As I'm sure you know, the dorsal turret on the AFM Bolo at Dayton is incorrectly from a B-18 -- the B-18A turret had a rounded top.

Rob
 
DennyA said:
Surprised to see a B-18 in USAF markings! What the heck was it doing in service that late?
Click to expand...

It wasn't really "in service".

If you stain your eyes and work through this photo
http://www.flickr.com/photos/bluedharma/5643001325/in/photostream/

you'll see that it was:
-Sept. 1944 "Declared surplus"
went through numerous civilian operators
-1959 ""Aircraft was seized by The Customs Department, sometime during the year, loaded with weapons reportedly bound for Cuba"
-Aug 1960 39-25 is transferred to the Air Force Museum at Wright Patterson AFB"
-Apr 1961 "... arriving at the Air Force Museum for permanent display

a/c is now at Wings over The Rockies Museum

When it was acquired by the AFM it was likely "Taken On Strength" and assigned a serial # and painted in a USAF scheme as it would be considered a "current" a/c. This would be to facilitate it's repair/prep for the flight to the AFM and because it became Air Force property.
 
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