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John,
Good question because I have been meaning to post something about this issue.
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I hope I stated that clearly.
Jim
Blueprint 76-42036 says …
Free length of the spring = 6.73″ +.19 / -.03.
Min Compressed length = 5.63
Total load to compress to 5.93″ = 2,440 lbs. +/- 245
Note says fill strut with fluid when 0.25 from fully extended position.
Matt,
So, you’re happy with the tailwheel oleo not fully extending after you rebuilt it? How far does it extend? Just curious.
Also, how does it sit at rest with 200# in the front seat and the equivalent of full fuel in the tanks, and then when you’ve added 200# to the rear seat and 50# on the rear platform, simulating aft CG? My point in asking is that the tailwheel pivot post should have a positive caster angle to it (i.e. the top end should point slightly aft of vertical), otherwise you could end up with tailwheel shimmy which will get worse when the aerodynamic force of up-elevator is added. I’m just trying to think ahead for you if you haven’t considered that yet.
Lastly, we (as in various other club members and I) have found rudder cables installed wrong-end-forward, as well as cables of the wrong length installed, and left swapped with right, and wrong-sized tailwheel springs. Those situations can frustrate your rigging attempts so it’s worth the extra checks before you set the tension.
Jim
Turned this up on a NSN search: HERE
Well, of course your tube would be longer! You wouldn’t admit to anything less, now would you? Harhar. Bad adolescent humor. but I couldn’t resist.
It took a little work to get to the bottom of this. The mast, which is called a “conduit”, was Government Furnished Equipment, so no dimensioned drawing exists in the blueprint set. The p/n was MI-5211-10. The antenna installation drawing 76-72003 is not in the NASM blueprint set either. Luckily, the parts list on the radio installation drawing 76-72100 indicates it was 10″ long. Doesn’t give a diameter or wall thickness.
I presume that you have the L-5 parts catalog. Give me the 76- part number and I’ll see if a drawing exists.
I’m a DIY sort of person. I haven’t done an L-5 data plate, but I have done a couple for antique British cars. First I did reverse electroplating that knocked the corrosion off without removing any metal (you want to avoid mechanical abrasion,) and then I re-plated (galvanized) it with zinc which looked very original and could have stood on its own without paint. There are lots of websites and, these days, YouTube videos that explain how. You could also do it with nickel, but that might be too bright.
After that I wanted the original black background but doing it by hand proved too difficult for me so I had a graphics company take care of the rest. They made a mask for the raised lettering and other unpainted areas, inked the plate, peeled the mask and it came out looking better than I had anticipated. Not quite like new due to a little pitting from the corrosion, but very acceptable. A matte black finish helped hide the little bit of pitting from anything but very close-up examination.
I’d guess there are other methods but others I know have simply had reproductions made and kept the original tag with the logs and paperwork. Technically, you need approval for a replacement if the plane was registered using the USAAF number, but not everyone wants to deal with the FAA / CASA / EASA for that. If you go the repro route, avoid aluminum because it’s a dead give-away that it is not original. A steel plate etched, stamped, lightly galvanized and then silk-screened would be per the original.
JG
p.s. The project numbers were also stenciled on the crates that the L-5’s were packed in for overseas shipment. I have at least one clear photo of that.
JG
Matt,
Short answer: for your plane, don’t add it. I’ll explain further on.
For all out there who might be wondering about PROJECT NUMBERS , they were assigned to various allocations of aircraft that went overseas. Here are a few examples: ten L-5’s were sent to the UK in November 1943 under Project 92327-R as replacements for L-4’s being used by the 153d Liaison Squadron, twelve L-5’s were sent to Fort Wainwright in Fairbanks, Alaska for cold weather testing under Project 96325, and twenty L-5’s were diverted to the RAF in India in June 1944 under Project DIV-1048.
All foreign allocations like that had separate project numbers assigned to them, even single planes requisitioned for special purposes such as an L-5 operated by the U.S. Consulate in Venezuela (a cover for the OSS). Unfortunately, no master list of these numbers or their meanings has ever turned up and many warbird people have looked over the years. We don’t even know where to look for them except on the aircraft record cards themselves. I only know what they are for our L-5’s because I transcribed the records cards for all 3,590 airplanes and put that, and a lot of other information, into a large database. There probably isn’t anyone else on the planet mad enough to have done such a thing, but it’s all right here at my fingertips for instant reference.
Anyway, the L-5’s (and presumably other aircraft) delivered within the Continental United States are a different story. Throughout 1943 and most of 1944 the project number DOM2148 was allotted, no matter where in the country they were delivered. Hundreds of L-5 Individual Aircraft Record Cards (IARC’s) bear that number, including the record card for 42-98774. However, on many other cards no project number is listed. I assume the same number applies to them, but I can’t be certain. After November 1944 different numbers begin to appear but, again, they weren’t always listed on the record cards.
With all this said, we now get to the crux of the matter – what to stencil in the data block of your airplane? As I said at the beginning – nothing, not even the words “Project Number” without a code after it. Although I don’t have a lot of vintage photos showing the data blocks, for the 8 or 10 shots I do have of L-5’s that stayed in the U.S., not a one has a project number on the boot cowl, and they run the gamut from airplanes #2 and #3 right out of the factory to an L-5E near the end of the war.
It’s possible that some had DOM2148 in the data block, but I haven’t seen one with it. Gerry Asher would be a good person to ask since he also has a large collection of photos, but the bottom line is that you wouldn’t be wrong to leave it off.
Jim Gray
It is used on all models John and you should have it installed. The O-435 needs all the help it can get for proper airflow and cooling. One of the big problems during development was cooling and every bit of that baffling is important, particularly item #7, the vertical front “scoop” .
JG
This is what Don Ayers found. They need the dimples added manually if you want to go that far into detail.sri-supplies.com/slab-base-weld-nut-832-x-14-38127000
As Charlie Brown would say, “Rats”, but I’m glad my method of checking the temp gauge worked for you. Changing the pressure relief valve does seem to be the logical next step. It sounds like it stuck open on your initial start when the oil was cold and the pressure was high and then it stayed that way for the whole first flight, causing low flow through the oil cooler. Then, after you pulled it, cleaned it and rotated the valve, it didn’t stick on the second flight and more oil was diverted through the cooler as it normally should. That seems to explain the intermittent behavior you’ve been getting. I don’t see why the valve from your -A would be any different in design from the -C. I believe the only difference between the two engines is in the accessory section. Good luck with the next attempt.
I’m glad that’s sorted John. I’m still embarrassed that I had forgotten there is a vernatherm in the oil cooler even though I had written about it in the past. I did not know about the superseded part because all six of the G&O oil coolers I’ve had in my hands over the years have looked exactly like Sam’s with the hole in the bracket. You’d think that at least one of our members would have run across it in the last 20 years. It just goes to show that no matter how much you tinker with these old birds, scrutinize the manuals, blueprints, service letters etc, there’s always something new to learn.
