Avionics Bending: Honeywell VSI/TRA

Honeywell VSI/TRA Display from TCAS-2000 System on the L-1011

Many of the L-1011's got upgraded with TCAS during their service time. The most commonly installed TCAS system on the L-1011 is the Honeywell TCAS-2000. I recently got my hands on a pair of Honeywell 4067644 VSI/TRA displays. The displays are vintage 1990s and will make the L-1011 simulator a lot more authentic, and, they are a lot of fun to work with. They take ARINC 429 input for both the VSI data as well as the TACAS data. The image above shows the VSI/TRA without any data sent to it, therefore, it indicates both TCAS and VSI as FAIL.

Here is a short demo of the VSI/TRA receiving Vertical Speed data from the ARINC 429 Primary bus

From: Honeywell TCAS-2000 Installation Manual

The VSI/TRA display runs off 115V 400Hz power and can take both ARINC 429 data as well as ARINC 575 ADC data. The 575 stuff is purely analog so not so interesting for working with the flight simulator, but the ARINC 429 stuff comes in very handy. Also, the VSI/TRA comes in a 41pin as well as a 55pin version. The ones that I have are the 41 pin version; and, here is the pinout for the 41pin VSI/TRA:

J1-1	VS +DC REF	ARINC 575
J1-2	VS DC RATE	ARINC 575
J1-3	VS -DC REF	ARINC 575
J1-4	Primary VS (HI)	ARINC 565
J1-6	Primary VS (LO)	ARINC 565
J1-5	VS 26 VAC Ref (Hi)	ARINC 565
J1-7	Not Used
J1-21	Not Used
J1-8	VSI Valid Flag	ARINC 575/565
J1-9	5V Lamp Dimming (LO)
J1-10	5V Lamp Dimming (HI)
J1-11	TCAS TA/RA (B)	ARINC 429
J1-26	TCAS TA/RA (A)	ARINC 429
J1-12	VS No 1 (B)	ARINC 429
J1-27	VS No 1 (A)	ARINC 429
J1-13	Not Used
J1-14	VS No 2 (B)	ARINC 429
K1-30	VS No 2 (A)	ARINC 429
J1-15	Config Common
J1-16	VS 26 VAC Ref (C)
J1-17	CS3	Configuration Bit
J1-18	PTM Common
J1-19	PTM PWR Out -15VDC
J1-20	PTM PWR Out +15VDC
J1-22	Chassis Ground
J1-23	115VAC 400Hz (C)
J1-24	Remote Light Sensor (LO)
J1-25	Remote Light Sensor (HI)
J1-28	Not Used
J1-29	RA Valid Out
J1-31	Source Select In
J1-32	CS0	Configuration Bit
J1-33	CS1	Configuration Bit
J1-34	CS2	Configuration Bit
J1-35	CS4	Configuration Bit
J1-36	CS5	Configuration Bit
J1-37	CS6	Configuration Bit
J1-38	CS7	Configuration Bit
J1-39	DC Ground
J1-40	115VAC 400Hz (H)
J1-41	CS8	Configuration Bit

The Vertical Speed input label for the VS 1 and VS 2 sources is Label 212.

Avionics Bending: Honeywell CD-800 Display Unit

Honeywell CD-800 Display Unit

Every now and then I need to take my mind off the L-1011 for a moment and go play with something totally different. Today I powered up a Honeywell CD-800 Display Unit. They are pretty neat little terminal units most frequently used on Gulfstream business jets and would be connected to something like a Honeywell NZ-920 Navigation Computer. While it is not totally unrealistic that such an avionics package could have been installed on the L-1011 I have not found any evidence that it was ever considered. The FMS on the L-1011 typically consisted of, for example, a Litton INS. However this unit is still a lot of fun and has a lot of ARINC 429, RS424 and RS232 inputs and it might become a good fit for the next project, the MD-83 project.

The CD-800 Control Display Unit (CDU) is the pilot interface with the FMS. The CRT displays relative flight information to the pilot. The pilot enters alphanumeric data into the system via the full alphanumeric keyboard. This data appears in the scratchpad to be line selected to the appropriate position on the CRT display. (from Honeywell Maintenance Guide)

Honeywell CD-800 Annunciators

Annunciators - The six annunciators located at the top of the CDU keyboard panel operate independently from the CRT and keyboard. Lighting of the annunciators is initiated by the navigation computer or performance computer via the RS422 serial data link. The two colors used for annunciations are white and amber. White indicates an advisory type annunciation, and amber indicates an alerting type annunciation (810 and up only). (from Honeywell Maintenance Guide)

Honeywell CD-800 Without Navigation Computer

Here it the block diagram for the unit:

(from Honeywell Maintenance Guide)