B-25 Engine (Santa Monica — < 200 fsw)

Background

A number of years ago, Tyler and I saw a drop-camera video of what appears to be a radial airplane engine and information that it was taken somewhere in Santa Monica Bay — but we didn’t have a location. That engine and video was located by Harry Davis Jr who recently passed away but made numerous discoveries in Southern California. He was a legend in the local diving & spearfishing community.

Ray at Sundiver International had a long relationship with Harry but Harry was unwilling to provide the location to us.

The video was analyzed by a few people and it looked like a 14-cylinder radial engine and it was connected to a wing segment which means that it came from a multi-engine aircraft. That narrows down the possibilities when you consider the record of crashed airplanes in that general area. We finally figured out it was likely from a B-25 BuNo 44-30047 that crashed during a test flight in February 1946.

Undeterred by the lack of GPS location, Tyler got the official accident report and we started mapping out potential targets. We spent multiple trips with Ray & Kyaa looking at targets on the Sundiver Express. We probably scanned at least 20+ targets and dove at least 5 over 2 or 3 trips — all without any success.

Unfortunately, Harry was nearing the end of his life and Ray was helping him get his possessions and affairs in order. At some point, Harry gave Ray the location on the proviso that Ray could only take one diver and somebody that he trusted to not provide the location. I was fortunate and honored to get the call from Ray when he said “how comfortable are you diving to 200 feet alone?” I just smiled and said “anytime.”

We scheduled a trip on June 19 2024 and had really nice conditions. Ray and Kyaa had placed the downline perfectly (as usual). It was dark but at depth but the visibility was good. I spent little over 20 minutes on the wreck site to photograph it to confirm the wreck and build a photogrammetry model. Deco was a little less than an hour.

I do not believe that I am the first diver on the wreck; however, this is probably the first time it has been extensively documented.

B-25 Mitchell

The B-25 Mitchell has an amazing history of service. It was a medium range bomber introduced in 1941 and there were almost 10,000 units built. It was a very forgiving airplane to fly and very durable. One B-25 was nicknamed “Patches” because it completed over 300 missions, had been belly-landed six times, and had over 400 patched holes. Sturdy indeed!

Doolittle Raid

The most famous mission for the B-25 was the Doolittle Raid. Japan had drawn the US into World War II and we had long sought to bomb Tokyo and other locations in Japan. The problem was that Japan was a long flight from any US air base and we hadn’t yet taken over most of the Japanese air bases in the Pacific.

Lieutenant Doolittle came up with a plan to launch B-25 bombers from aircraft carriers. There was only one problem: it had never been done. In fact, no type of bomber had ever been launched from an aircraft carrier that was 600 miles from Japan. Under the final version of the plan, 16 B-25 Mitchell bombers with crews of five people were launched from the USS Hornet . They had no fighter escorts and the didn’t have enough fuel to return back to the carrier so they continued on to land in China.

It was the first bombing raid on mainland Japan. It didn’t do much damage; however, it served as a rallying point and was a massive boost to American morale and served as a “answer” to the raid on Pearl Harbor. It really demonstrated the versatility and power of the B-25 Mitchell.

Wreck Photos

The wreck site is a debris field largely spread out which makes tracking of what parts are where a bit tricky. But, there are a number of clues about the identity of the airplane type at the wreck site. Below are some photos and commentary.

First is an overview of the debris field from the photogrammetry model with some key features noted:

Below is a cutaway that also illustrates some key points:

The engine is obviously a radial engine and is obviously attached to a wing section and not a single engine (see photogrammetry model overview above for more context). I’ve labeled some of the cylinders. You can see about a third of them in any one photo.

The wing section is next to and attached to the engine:

This photo shows the dual oil coolers. You can also see a note in the schematic above that indicates that the B-25 had two oil coolers for each wing mounted engine.

The nosecone and prop section are shown below:

The B-25 had a landing gear and tire basically underneath the engine which is also indicated in the screenshot of the wreck debris site.

The B-25 had multiple fuel cells inside the wing section next to the engine. I believe that these photos depict a portion of those tanks:

Photogrammetry Model

As shown earlier, I did build a photogrammetry model of the debris field. It isn’t easy to build these models given a lack of consistent structure but it does help see the relationship between the various pieces of debris.

Below are links to the on-line version of the model:

ADD LINKS HERE

Wreck Identification

Given that the wreck is a portion of a B-25 that is in Santa Monica Bay, there really aren’t any other possibilities other than BuNo 44-30047 which is a CB-25J Mitchell. This specific airplane was modified for company transport for North American Aviation and was meant to replace another B-25 serving in that role but had been written off in a crash landing a year earlier.

The airplane was on a test flight when an engine caught fire and it crashed into the ocean killing all three people. It was the second flight of the day and they were planning to test stall and speed calibration tests.

This is the entry from the Aviation Safety Network database:

There is also some good information from the site Joe Baugher maintains with airframe serial numbers. Specifically, on a page dedicated to B-25 VIP Transport Conversions:

The loss of 40-2165 had left North American Aviation without a company transport, and B-25J 44-30047 was converted as its replacement. 44-30047 was quite similar to the planes that had been modified for Generals Arnold and Eisenhower, but incorporated some differences. The standard eight-gun nose shell was used, with a large door being cut into each side to provide easy access to the heater and radio equipment inside. The radio direction finder was mounted on the underside. The converted aircraft flew for the first time on October 18, 1945. However, it crashed off Malibu on February 27, 1946 following an onboard fire, killing veteran test pilot Joe Barton, test engineer Cowles, and CAA inspector McCutcheon.

There were a few newspaper articles about the crash as well:

Next Steps

This part of the wreck obviously raises a key question: where is the rest of it?

I can say that the engine is not exactly where we expected it to be. We have the 47 page accident report which contains a lot of clues and information. For example, the accident report also makes it clear that the wreck was NOT salvaged which means that the rest of the wreck is somewhere:

The section we discovered is, in reality, probably less than 25% of the entire airplane.

One factor comes to mind:

One of the airplane engines caught fire and the airplane “began to spiral and made three or four turns in small circles when the right wing hit the ocean causing the plane to nose over and disappear into the water.” I did NOT notice any fire damage at the site which leads me to believe that this was right wing that was still attached to the rest of the plane. The next assumption is that the rest of the airframe is relatively close.

Eyewitnesses and sections of the report indicate an oil slick that is somewhat further away from this wreck site which contradicts the above assumption. It could be that the rest of the airplane is deep in the trench off Malibu / Santa Monica. The Navy & Coast Guard spent significant resources dredging trying to find the wreck and couldn’t.

Our next step is to continue to look at some additional targets Tyler has located. I really hope that we find the rest of the wreck, but prospects are pretty tough to do that.

Thanks To…

Obviously a huge thanks to Harry for finding the wreck initially. He made some amazing discoveries and had quite a life.

Thanks to Ray for trusting me to make the dive and to document the wreck and the story of this aircraft. Thanks to both Ray & Kyaa for getting me on the wreck, a perfect downline placement, and a safe platform for conducting these dives.

Thanks to Tyler for collaboration on many projects, including this one even though Tyler hasn’t yet had the opportunity to dive it. We’ll find the rest of it together!