[ARC5] [Milsurplus] XTB2D-1 Skypirate avionics

[Mike Morrow]

The reported configuration is a version of the AN/ARC-5, AN/ART-13, AN/ARR-2, ARB, and AN/ARC-4 (or AN/ARC-1) combination system that's shown on sheets 8 and 9 of Figure 8-55 in the Handbook of Maintenance Instructions for AN/ARC-5 LF MF HF Components, AN 16-30ARC5-2.  Mike Hanz has Figure 8-55 here:

 http://aafradio.org/docs/ARC-5-HF_manual_Figure_8-55_sheets.html

In this system's combat configuration, the C-38/ARC-5 controls these things:

1.  R-4/ARR-2 Audio, Mode, and Modulation Frequency Selection.
    (You report that Mod Freq Channel 4 is pictured.)
2.  Audio from VHF Receiver A - RT-19/ARC-4 (or RT-18/ARC-1).
3.  Audio from MHF Receiver B - ARB *FIXED* tuned on one frequency.
4.  Audio from MHF Receiver C - R-25, 26, or 27/ARC-5, FIXED tuned.
5.  Mic selection to AN/ART-13 or AN/ARC-4 (or -1) or ICS.

The T-47/ART-13 is controlled by C-87/ART-13.
The RT-19/ARC-4 is controlled by C-51 or -52/ARC-4
  (or RT-18/ARC-1 by C-45/ARC-1)

The ARB and the single AN/ARC-5 receiver antenna inputs
  are connected to the REC post on the T-47/ART-13.
The R-4/ARR-2 connects to its AT-5/ARR-1 whip.
The RT-19/ARC-4 (or RT-18/ARC-1) connects to AT-8/AR whip
  or AN-104 mast.

The above represents the COMBAT configuration.

For FERRY configuration, the normal control/power cable is disconnected from the ARB.  A FERRY control cable is installed at the ARB control/power connector that goes to a CRV-23254 pilot's control box which now provides full control of the ARB and probides audio connections.  Power is supplied to the ARB in FERRY service through a two-conductor cable connected to the power-only connector on the ARB.  A CRV-23253 tuning head and spline shaft are connected to the ARB.

The ARB and AN/ARC-5 receivers provide just two fixed MF/HF receive channels for the 10-channel AN/ART-13.  Multi-channel MF/HF receivers were beyond the USN until the R-105/ARR-15, unless one counts the 6-channel C-131/AR kludge that was added to some R-26 and fewer R-27/ARC-5 receivers.

The flexability of the ARB was available only for FERRY configuration.  In COMBAT configuration that same ARB is just one big fixed mode single-channel MCW-mode receiver.  Doubtless, the FERRY configuration would be used any time there was a non-combat flight in transit over non-hostile territory, where the tunable versatility of the ARB in conjunction with the 10-channel T-47/ART-13 could be valuable.

The right third of the C-38/ARC-5 looks like a C-2/ARR-2 because that's exactly what its function is.

Mike / KK5F

-----Original Message-----
From: Hubert Miller 
Sent: Dec 4, 2017 10:24 PM
To: "milsurplus at mailman.qth.net"

Here's something I wonder about. A friend sent me a copy of the "Right Hand Pilot's Console XTB2D-1 Skypirate".

Two prototypes were flown in 1945; the plane would have been the largest carrier plane of the time, but was shortly cancelled.  Anyway, the control boxes shown are:

ARB tuner; ARB control box (actually, ICS box is labeled as this. No actual ARB control box is shown, just the tuning head. Drawing mistake.
The ARB control equipment is captioned, "FOR FERRY FLIGHTS ONLY". 

ATC  control box 
APX-2 IFF control box 
C-38 / ARC-5 control box
ARC-1 control box
unid interphone control; narrow unit has from top to bottom:  ICS / RADIO;  CHANNEL A, B, A&B ; ICS VOL / OFF.
 
There is no tunable ARC=5 head. The C-38 has a tuning knob but shows only a "4" in the window, kind of like the ARR-2 control box.  (I have not owned a C-38 for many years, so I don't remember its particulars.)
 
My question is, so in this case, the ARC-5 was used in channelized operation with the ATC, okay.  What was the ARB included for, for ferry flights. (Which though anticipated in the design phase, but never actually flown in this aircraft.
-H