When does "Two" sound like "Three"?
 

I apologise if this has been covered extensively before, but is it not time that the english words "Two" and "Three" were reviewed or in someway altered so that they cannot be mixed up in RT transmissions?

I have been finding that some RT users speak so quickly, and with no clear pronunciation so that it happens that frequencies or cleared flight levels become confused. ie " cleared climb flight level Troo Troo zero"

What the hell does that mean- is that a three or is it a badly spoken two not helped by static during the transmission.

The potential for a foul-up is obvious.

Contact one troo troo decimal nine two..........

Sorry say again that frequency?

Okay sometimes the confusion is resolved by either expecting to change to a frequency that one is already familiar with, or the flight level is obvious by the fact you are already well past the level.

Nevertheless cannot someone decide a realistic and sensible alternative which can remove this confusion?

What d'ya think?

Answers on a postcard please to the ministry of common sense and clear communication!

Postcards from the edge
 

<<I have been finding that some RT users speak so quickly, and with no clear pronunciation so that it happens that frequencies or cleared flight levels become confused. ie " cleared climb flight level Troo Troo zero">>

Actually I think the poor enunciation is more the problem.

Personally I don't think we need to change the pronunciation of Two and Three.

We just need to speak slower and clearer (and maybe upgrade our equipment while we're at it).

Two & tree... Never had a problem myself.

The whole point of using phonetics I'd have thought.:)

Deux et trois peut etre?

I always have problems with my twos and threes on the RT and pilots frequently mishear things I am telling them. Poor diction is not to blame. I am from Manchester and the flattening of the sounds I make when I speak causes twos to sound like threes and vice versa.

It is a problem I am aware of, and I always listen out carefully to readbacks to make sure I pick it up

I have a problem with people saying "NINE" not realising that it can sound very much like a "FIVE" over the radio.

"NINer" has two syllables for a very good reason!

missioncontrol and halo

Are you saying there is a problem with the (incorrect) combination of "two/three" or with the (correct) combination "two/tree"?

G W-H

The spanish accent makes the two very difficult to tell apart.

And I thought that it was my aging ears!
Especially over the last 5 years I have noticed this problem growing, and I think it is more due to people drifting back to their natural accents instead of using the strict requirements of the book.

The phonetic numerals were carefully designed so as to be only dependent on the vowel sounds and not the consonents, apart from 'zero', which I have never heard poorly stated or misunderstood. But the 2,3 ambiguity is so often a cause for correcting read backs, and potentially a safety issue - QNH 1020 v 1030 is 300ft!

UN = 1, OO = 2, EE = 3, OR =4, short I =6, short E =7,
long A =8.

As said earlier EYE could be 5 or 9, so we have fiFe, and ninER.
When did you last hear either of these spoken properly?

Perhaps if AlanM or SATCO is on this he could comment from ATC.

Mike.

Being a professional air traffic controller and working at a busy twin runway airfield somewhere west of London, I always pronounce them "Two and TREE" not "Two and Three". As mentioned before because of my regional accent there is a tendancy to flatten sounds which makes them sometimes difficult to distinguish. This is by no means the worst problem... As mentioned, Niner and Fife are difficult as well, as illustrated a few years ago by having UAL 959 and UAL 955 on the frequency who continually took each others calls despite being told numerous times of the presence of each other and then need to LISTEN CAREFULLY!

Some of the problem as well stems from the fact that a lot of crews are busy and so aren't always 100% focussed on listening to the frequency, and as such tend to mishear things by catching only part of a transmission and then guessing at the rest of it. This has happened to me on so many occasions that I have lost count, and instead of asking for a repeat they stumble over it instead

During flight training I was taking a C172 VFR from Fort Pierce to Ket West. Callsign N1247M. Everyone I Spoke to had problems and keep thinking I was calling 1347M. In fact it got so annoying that I adopted the callsign N1347M to make things easier. There was so much airtime being taken up that I felt it was less stressful to become a tree instead of a two. Three was never a safety issue under vfr and I think I might even have enhanced safety around busy terminal areas by minimising RT.

Two/Three
 

Although long retired from flying I still do the occasional A/G operation at our local airield as well as being an RT examiner. I always try to use the standard TOO and TREE. So far I haven't had any trouble.

Vizcaya - easy to tell apart, 'ten' isn't permitted for use - well normally :}

Like Halo, suffering from a Mancunian accent I have had numerous problems with 2's and 3's, and ironically solved it by using the OFFICIAL pronunciations of 'too' and 'tree'. I do always listen specifically for these in readbacks for when the laziness kicks in :E

I have to say that 2/3 confusion is the most common mistake that I (and others with me) make.

If I don't get a reply on 12X.XXX, I'll quickly try 13X.XXX, or vice-versa, before going back to the original frequency. It doesn't seem to matter how carefully you listen or read it back, you often end up on the wrong channel.

It seems much rarer to make that kind of error when accepting altitude clearances, although RVSM might be increasing the chance of this happening. Virtually everything on ATIS is susceptible to mis-interpretation but at least you might have a forecast/old actual to pick up any gross errors from.

I notice that more and more airfields require you to read back the QNH as well as the ATIS letter - a possible 10hPa difference in setting could be embarrassing, at the least...

One last observation. I don't have a problem in normal conversation on the ground/in the flight deck in telling the difference between "two" and "three", let alone "TOO" and "TREE". Maybe the bandwith limitation on VHF R/T reduces the difference between the two spoken words...?

Many Nigerian pilots and controllers use 'fiver' as well as 'niner'. I have no idea why this is so.

Would it not be possible to use the phonetic FREE rather than TREE since it is less likely to be mistaken for TOO as it doesn't share any of the same letters.

I believe that the phonetic TREE came into existance before the needs of those to whom english is not the primary language were considered.

every day
 

I have to ask again is it 2 or 3......flying over Italy, or France, on sectors that I dont fly that often...

and as an aside, I often use the word towards rather than to, when cleard to a flight level.....just to assist in reducing the confusion with the word TWO....bumz

Excuse me for butting in on a pilot forum guys, but I get foreign pilots (especially southern european) who question my 'two' and 'three'. Then Brits on the frequency start doing it as well!
And I know it sounds a bit 'estuary english' but as an ATCO I'd prefer to be able to use 'Free' rather than 'Tree'.
BTW, I'm from Belfast and work at BRS.

Sorry, off back to the ATC forum again.:D

When does two sound like three?

When it's said in German....Zwei, Drei....:O

Regards,

Old Smokey