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lynnpype
14th Jul 2007, 03:41
Hello,

I recently saw a video covering ILS approaches in a Boeing 737-200. I have a question regarding particular callouts made before landing.

During every approach, the PNF called out a series of numbers with approximately 5 seconds between each callout, like this:

"plus 867 (5 seconds)
plus 767 (5 seconds (also at every callout below))
plus 868
plus 1067
plus 867"

or

"plus 567
plus 567
plus 867
plus 867
plus 767
plus 767
plus 567"

These callouts were made during short final, after finishing the landing checklist until touchdown (during one occasion a callout was even made 2 seconds before touchdown).

I didn't hear these kind of callouts during similar approaches in Boeing 737-400's or -800's.

What are they exactly calling out?

Thank you, kind regards,
Lynn Pype

waav8r
14th Jul 2007, 04:43
Hi Lynnpipe,
You have almost certainly seen/heard a video of a Pommie-crew in action, as they are known to engage in the kind of verbal diarrhea you have just witnessed;). To understand what you have heard it is useful to break up the statement as follows;
First bit "Plus 5 (or Plus 10)": refers to speed above Vref, so if computed Vref is 132KIAS, the speed observed and called by PNF would be 137 (or 142) knots.
The second bit - the "6" that you quote in the middle of every callout, must be the way this particular PNF announces the word "SINK", ie Instantaneous Vertical Speed (IVS) at the moment of the callout.
You have probably therefore already figured out the third part of the
statement - that is the IVS in hundreds of feet, so that for instance "Plus 5 -sink 7" would mean; Observed speed is Vref plus five knots - sink rate is seven hundred feet per minute.
I am pretty sure I know which operator you have heard in action as well, and if I am right -they adopted this whole SOP from a previous BAC 1-11 operation. Their SOP is for the PNF to initiate this whole procedure at five hundred feet above touchdown, and keep blabbering on until the aircraft has touched down.
IMHO - not a very good idea if you are waiting for a late landing clearance, but of course has some merit if the PF happens to be in his senior years (having retired from BA and are now enjoying making noise with a pair of JT8D's) and at five hundred feet AGL have just flicked his reading glasses (that he needs to read the instruments) up to his temples, and can now focus his entire attention at averting the grassy bits surrounding the tarmac bits.
It is however not standard Boeing SOP (and thank goodness for that):ok:.
Hope this helps - waav8r

mactheconny
14th Jul 2007, 11:56
Something you don't hear of very often, an Aussie exagerating :rolleyes:

Fair dinkum, no word of a lie etc.

lynnpype
14th Jul 2007, 15:53
Hello,

Thank you very much for this clear answer !

When I listen again to what is being said with your answer in mind, the "6" can indeed be understood as "SINK". Just another example of how you hear what you expect to hear (SINK between 2 numbers becomes a 6 this way, it sounds like 6 and you expect another number between 2 numbers).

Your guess on the operator is probably also correct. It's indeed a small British airline based at EGHH, and they did operate BAC 1-11 jets before they were retired due to noise regulations. Currently they only operate 732's.

Thanks again for the excellent answer!

Kind regards,
Lynn Pype

waav8r
14th Jul 2007, 17:32
You're welcome Lynn Pipe.

Hey ASFKAP - what's with the Aussie-bashing???:}

A37575
15th Jul 2007, 13:23
First bit "Plus 5 (or Plus 10)": refers to speed above Vref
Maybe - maybe not. Depends on the operators SOP and they vary significantly from pure cant to something you can rely upon as being accurate and concise. The speed call could be the knots above or below the selected approach speed. Or it could be above or below Vref. Big difference.
If due to gusty winds the pilot elects to add 15 knots to Vref and aim to fly on final at that speed, then the SOP call could be Plus 15. On the other hand if the call is based upon variance from selected approach speed there may be no call needed. If however the call is again based upon selected approach speed and the pilot is lightly faster say by 2 knots - then the call could be Plus Two.
Plus 2 (above selected approach speed) doesn't raise eyebrows with most pilots under these conditions but a call of Vref Plus 17 may cause concern if the runway length is limited or surface slippery. What affects the landing is the number of knots in excess of Vref.

Regardless of the above, there is nothing more annoying and dangerously distracting than the PNF keeping up a more or less continuous chatter of unnecessary calls. It may sound good on the voice recorder and keep the legal people smiling, but there is no flight safety value at all.

waav8r
15th Jul 2007, 16:44
"Quote:
First bit "Plus 5 (or Plus 10)": refers to speed above Vref
Maybe - maybe not"

Ehh well A37575, in this particular case (EGHH based airline owned by petrol head from Downunder) - there is no maybe - maybe not, it definitely IS (above Vref that is)! And I concur - if you are going to do something like this, it would make far more sense to have TARGET airspeed as reference for the variations in the calls, rather than Vref. You would think that if you actually fly EXACTLY what you have said you are going to fly, for instance target airspeed Vref plus 10 knots - that you would be rewarded with a bit of peace and quiet as you are concentrating on the task at hand, but no - you would still hear "plus ten - sink whatever".

And I suppose, that's what can be as you say; " nothing more annoying and dangerously distracting than the PNF keeping up a more or less continuous chatter of unnecessary calls." Not sure about the dangerous bit, but annoying - oh yeah!

As i said in my initial post, there may be pros and cons about this, but in my mind - thankfully, it hasn't cought on in the industry.