Question Shuttle voice com phraseology

[Thorsten]

I was wondering whether anyone has come across a document that outlines standard voice com phraseology for the Shuttle.

I've come across the abort region callouts during launch

two-engine TAL
negative return
press to ATO
press to MECO

and

limits to inhibit

and I'm fairly sure there must be quite a bit more standardized phrases, but I can't recall seeing a complete list.

Any pointers appreciated.

 

[Urwumpe]

I was wondering whether anyone has come across a document that outlines standard voice com phraseology for the Shuttle.

I've come across the abort region callouts during launch

two-engine TAL
negative return
press to ATO
press to MECO

and

limits to inhibit

and I'm fairly sure there must be quite a bit more standardized phrases, but I can't recall seeing a complete list.

Any pointers appreciated.

Well, for the first ones, you would get to this NASA workbook:

https://www.nasa.gov/centers/johnson/pdf/383447main_intact_ascent_aborts_workbook_21002.pdf

Chapter 2.2.1 describes them precisely.

I am not sure about the "limits to inhibit" there, some context for the call would be necessary. Is that from the Post-Insertion Checklist?

 

[Thorsten]

The workbook I have, and I'm not interested in what the callouts which I posted mean (I know that) - I'm interested in what other standard phrases are used during other mission phases. Sorry for not being clear enough.

There's plenty of chit-chat going on between MCC and the Shuttle as evident from video footage, but I assume there would be standardized phrases for important things - like insertion burn parameters, or instruction to do certain things...

('Limits to inhibit' instructs the crew to disable the engine operating limit checks during ascent after they've lost one engine - with three engines it's better to switch off a suspicious engine to keep it intact, with two engines it's usually better to cross your fingers and keep a suspicious engine running as long as it will hold up, 2EO scenarios aren't that pleasant).

 

[Wolf]

I'm interested in what other standard phrases are used during other mission phases.

Do you mean also standard callouts like the ones made during the Approach phase about the energy state of the orbiter or like the post landing ones from the crew and MCC?

 

[Thorsten]

Yes - any mission phase - anything that's standardized.

 

[GLS]

('Limits to inhibit' instructs the crew to disable the engine operating limit checks during ascent after they've lost one engine - with three engines it's better to switch off a suspicious engine to keep it intact, with two engines it's usually better to cross your fingers and keep a suspicious engine running as long as it will hold up, 2EO scenarios aren't that pleasant).

Normally when a SSME shuts down, the GPCs immediately send a command to the remaining engines to inhibit limits (ignore the redlines), to prevent the loss of more SSMEs in a short period of time. That's when the SSME Limits switch on panel C3 is in AUTO. With the switch in ENABLE, the GPCs send the limits enable command to the SSMEs, and if a SSME fails the GPCs do nothing. With the switch in INHIBIT, the GPCs send the limits inhibit command, and do nothing if there's a shutdown.

I don't know the procedure, but yes you want to avoid contingency aborts as much as possible so you might want to keep a suspect engine working to make it to SE TAL or at least SE OPS 3.

In situations where, for whatever reason, you manually shutdown a SSME, the MCC might do a "Limits Enable, Auto" call. This is done so the crew cycles the limits switch to ENABLE (to send the limits enable command) and then to AUTO (to have the GPCs inhibit limits if another SSME fails).

 

[Urwumpe]

Most radio calls simply follow classic radio conventions, especially NATO military and aeronautical conventions.

For example, you use abbreviations as often as possible to abbreviate the communication, at the same time use very distinct phrases to make sure they are not misunderstood.

 

[Thorsten]

at the same time use very distinct phrases to make sure they are not misunderstood.

I do have the certificate to do German and English flight communication, so I'm well aware of the underlying principles. It's the 'very distinct phrases' for the Shuttle I'm looking for.

Standard aircraft phraseology doesn't really cover operating a Shuttle - much of it involves asking for various clearances, but 'Atlantis, this is Kennedy tower, your QNH is one zero zero niner, you're cleared to land on runway three three' isn't really how it's done :lol:

 

[Linguofreak]

Nah, the only difference is that they say it when the Shuttle is somewhere over Australia. :rofl:

 

[Thorsten]

So, leaving the humorous detours aside, may I assume no one knows the specification either? Thanks in any case.

 

[Urwumpe]

So, leaving the humorous detours aside, may I assume no one knows the specification either? Thanks in any case.

Aside of Ascent, Rendezvous and Entry, there are no clearly defined calls. And if you think about it, you can imagine why it makes no sense to be too specific there.

 

[Thorsten]

Well, if you know any list of clearly defined entry or rendezvous calls (or ascent which I have not listed), would you mind sharing them here?

I can imagine a lot of things, but I'm really interested in NASA procedures here.