Type LOOP LP-21

[loopbomber]

Attached is an non static loop antena and i wondered how i can tell if this was off a B-17 or another aircraft in WW2.

 

[Wurger]

The Radio Compass DF Loop LP-21 antennae used for multi-engine US aircraft like the B-17, B-24, B-29 B-25 and many others.

The full inscription should be :

LOOP LP-21 ... <- and here one or two letter/s indicated the type. Clean slightly the area up to find the last sign/s.
NONSTATIC
CORRECTED
T.O. ...-...-... <- here the Technical Order number. Your seems to be 2-3-3? but it was overpainted. Also required cleaning at the end sign to fine the correct ending digit.
DATA LINE NO. ... <- here a number also cleaning of the area is required to get it.

 

[loopbomber]

The Radio Compass DF Loop LP-21 antennae used for multi-engine US aircraft like the B-17, B-24, B-29 B-25 and many others.

The full inscription should be :

LOOP LP-21 ... <- and here one or two letter/s indicated the type. Clean slightly the area up to find the last sign/s.
NONSTATIC
CORRECTED
T.O. ...-...-... <- here the Technical Order number. Your seems to be 2-3-3? but it was overpainted. Also required cleaning at the end sign to fine the correct ending digit.
DATA LINE NO. ... <- here a number also cleaning of the area is required to get it.

Once I clean and get that additional information will that then let me drill down to what aircraft.

 

[Wurger]

Rather no, it won't. I doubt it can be found to what particular aircraft it was attached to. The full marking may help in getting the number of aircarft types limited.

 

[loopbomber]

Does paint help. I see a blue paint with a little bright yellow as well. The color is on the actual plane and not on the Loop as they cut part of the plane to get the Loop.

 

[Wurger]

Certainly the blue paint could help if we would know if it was attached to the top or bottom of the aircraft. But I can't remind myself a such blue colour on the bottom of the B-17. Usually it was the neutral grey colour if the bomber was camouflaged or the NMF ( natural metal ) if no camouflage. The same regarding other US bombers.
IMHO ... the Technical Order ( T.O. ) may be a better clue. It is because the code should contain the code of the manufacturer and the plane.

 

[loopbomber]

Here is the cleaned loop if that help identify date or what possible planes it went in.

 

[loopbomber]

Certainly the blue paint could help if we would know if it was attached to the top or bottom of the aircraft. But I can't remind myself a such blue colour on the bottom of the B-17. Usually it was the neutral grey colour if the bomber was camouflaged or the NMF ( natural metal ) if no camouflage. The same regarding other US bombers.
IMHO ... the Technical Order ( T.O. ) may be a better clue. It is because the code should contain the code of the manufacturer and the plane.

Wurger, I was able to add in all the TO numbers.

 

[Wurger]

Hi again,

The LP-21-LM .. may identify the B-17 or B-24. Or C-47 and P-51 as I have seen the type on them too. The T.O. 12-3-3 should help. Unfortunately I can't access all soures as I'm working using not my computer.

 

[cvairwerks]

If the aircraft carried either the SCR-269 or the AN/ARN-7 radio compass, it carried the LP-21 antenna. Even the lowly T-6 carried one of those two radios at times.

 

[Wurger]

I have tried to find the T.O that can be noticed on the antennae case. Either it could be the T.O. 12-3-3 or T.O. 10-1-301 ( also 1C-1-301). But nothing was found. However I noticed that there was the another TO applied there .. T.O. 01-1-152. The Technical Order was for the Radio Compass Quadrantal Error Correction from September 1944 and repeated in a couple of the next years as well. It contains the list of aircraft with the LP-21 antenna equipped. What is more it should be kept in mind there was a couple of the LP-21 variants ... eg. LP-21-A, LP-21-B, LP-21-AM, LP-21-F, LP-21-L and the LP-21-LM. The LP-21-LM was a part of the SCR-269-G and the *AN/ARN-7.

the pic source: Radio Compass Quadrantal Error Correction [jansejw31]