I did some digging and I think I’ve found something in regards to the propellers. It seems that you are correct that the version the maintenance manual covers does indeed have fixed props. Seems that due to poor performance at higher altitudes the propeller was switched on later models, specifically the 247D. All the mentions of this propeller lead me to believe it is a two position hydraulically controlled prop but I can’t be sure as there is no specific data on it. Frank Caldwell was the designer of the prop while working as chief engineer for Hamilton Standard. I looked up information on him and again most of the articles say it was a two position prop he designed that won him the Collier trophy in ‘33. This was a two blade prop though and I think our model here has a three blade? Here’s a link to a picture and description of this prop: https://airandspace.si.edu/collection-objects/propeller-controllable-pitch-two-blade/nasm_A19350039000#:\~:text=The%20variable-pitch%20propeller%20advanced,/hr%20(171%20mph).
It looks like the prop used on Roscoe Turner’s plane was a three blade prop, I believe this was the first D model. For the life of me I cannot find anything about how it works other than the stereotypical “it’s the gearshift of the air”, yes thank you, but how does it function. Some call it variable pitch and some call it controlled pitch. This article also says that the three blade props are ground adjustable props: Boeing 247 performance | aircraft investigation info | passenger aircraft
If I could just find a model number for the prop this would be so much easier to figure out.
The good thing is that this discussion is making me want to fly the 247 again. I haven’t flown it in a while and I do recall it being a joy to fly. Time to put on some 30s music and just cruise.
I’d known the earlier models had the two blade. I noted no mention of feathering switches/pumps in the maintenance manual, so that must have been an addition with the variable pitch props, too.
EDIT:
Hmm…
Looking at the manual for the simulated airplane, I found this:
”The Boeing 247D featured such an advanced
system which made her faster and more efficient
than her predecessor, the 247. The three-bladed
propeller of the 247D is a constant speed,
“Hydromatic, quick-feathering” Hamilton
Standard 23D40 with their hydraulic governors
being mounted on the rear plate of the engines.”
Note the “constant speed” and the model number “23D40”.
Here’s page 1 of the Hamilton Standard 23D prop specifications clearly stating constant speed:
At the risk of showing all my ignorance… If the real 247D had constant speed props, couldn’t the custom code just be swapped out for more standard code?
Bravo sir, you found what I couldn’t. I did not think to check the simulated manual for a part number.
It is definitely a constant speed prop then, which as you said brings back the question of why they do what they do. Good stuff, that was fun to try and figure out.
What is unknown is how the custom code is all interconnected. Again, since it is WASM, I can’t look at the code.
I’ve had two CTDs the last two times I was using the 247D. One when checking things out while still on the apron and one when flying for about an hour.
I don’t know if they are a sim issue or a this plane issue. If the latter, I’m going to have to rewrite the aircraft’s systems without WASM (unless I go down the route of learning how to do WASM-based code, which I am not against doing). It would most likely cause the loss of custom features like the load out and oil grade selection, etc. Even if I do learn about writing custom WASM-based code, it would be some work to replicate all that Otmar implemented. Again, I am not against it, but there is much to learn to accomplish it.
I just had a great flight in the 247D from Kingston, Jamaica to Camaguey, Cuba. I was even able to pick up a jazz station somewhere out there.
I picked up a set of DC-3 prop/throttle/mixture levers for my Honeycomb Bravo and they work perfectly for the 247D, since the lever layout is the same. That worked out well!
I’m glad the flight was successful. The last two times I’d tried the 247D the sim CTD. I was worried that it was going to be a consistent issue.
I took the 247D out the other day with Nixon’s mod and had a simply wonderful flight. Took off out of Great Falls, Montana and headed south following the beacons from the arrows across America mod. I initially tuned a range station but following beacons make that redundant so I switched the music on. I made one landing before stopping the flight with a landing at Helena. I forgot how enjoyable this plane is, with the sun slowly setting, a perfectly trimmed plane, rumbling 1340s, softly blinking beacon lights and some 1930s music in my headset, just an absolutely perfect flight.
Plane performed admirably as well, no issues other than the occasional all gauges jumping thing it does. But I don’t think it coughed up oil when it did those jumps as I still had plenty after I landed.
There are a couple unofficial mods that attempt to address the small issues of the 247. One was done by Ala13_Kokakola on flightsim.to and one was done by NixonRedgrave on the same site. Here are links to both:
Both fix issues, the Kokakola mod has more sound fixes and NixonRedgrave’s is a bit more technical in the nature of its fixes. There is a lot of discussion around these mods further up in this thread that can help you decide which one to try. Either one simply adds more to this already great aircraft. Hope that helps you out.
FS2024 landing in KJFK this aircraft is wonderful i hope some improvement will be with Redux mod the mod is nice too id like tu improve the level of the sounf in the cockpit that in fs 2020 was stronger…always thanks to redredux
