The call of "SPEED." Is it too vague?
Thread Starter
The call of "SPEED." Is it too vague?
The Boeing 737 Flight crew Training Manual (FCTM) under the heading of Callouts, states: "The PM calls out significant deviations from command airspeed or flight path." It is left to the operator to define how this is done. Perhaps the most common expression for significant airspeed deviations from the norm is "SPEED" called by the PM. The speed tolerance is up to the operator and is defined in the company FCOM.
Recent incidents/accidents where erroneous flight instrument indications have been suspected, suggest that airspeed indications between captain and first officer airspeed indicators and possibly the standby ASI, have differed, leading to uncertainty and confusion.
"SPEED" as a support call from the PM usually means the PF is out of tolerance. But to what extent and in what direction - too fast or too slow? Perhaps "Speed fast" or "Speed slow" would be more precise - especially if an erroneous airspeed indication was the problem. A quick glance at the third ASI as the umpire, may help clarify things promptly -assuming that ASI is unaffected because of its different information source. This is the reason for the third ADI - to act as umpire.
A call of "SPEED FAST" from the PM would hopefully immediately prompt a query from the PF, if his own ASI was indicating correctly to his eyes.
In the early days of the 737-100/200, Boeing recommended (for the approach and landing case) the airspeed support call be based upon the planned Vref speed. For example "Vref plus 15." This policy was based upon the fact that anything faster than Vref at the threshold would extend the landing distance. The current limit of Vref plus 20 knots is till the upper figure beyond which the potential for an over-run beyond the scheduled landing distance becomes serious.
A planned approach speed of Vref plus 20 knots (this would generally mean headwind component and gust additives combined) would not be subject to a out of tolerance support call if the airspeed was within company tolerance. Nevertheless a heightened sense of speed awareness engendered by reference to Vref would surely be good airmanship - particularly if runway length limited or wet surface.
Thus, two knots over the additives doesn't sound very much - but a support call of "Vref Plus 22 knots" puts a whole new urgency into the support call. A call of "SPEED" by itself becomes meaningless.
Many years ago, an airline in Australia introduced a support call at 500 feet above airfield elevation, of airspeed deviation above Vref and rate of descent. This was intended to remind the crew of the lower limit of stabilisation on final, whether IMC or visual. A typical call by the PM would be "500 feet - Vref plus 12 - Sink 800." The call emphasised the airspeed above Vref - not the airspeed above the Vref plus additives. "Bug plus 2" sounds positively benign in meaning, when compared with "Vref plus 22"
Regardless of company policy on speed tolerances before a warning (support) call is warranted, "SPEED FAST" or "SPEED SLOW" is more precise that the one word "SPEED." It also has the added advantage of quickly picking the onset of erroneous airspeed indications.
Recent incidents/accidents where erroneous flight instrument indications have been suspected, suggest that airspeed indications between captain and first officer airspeed indicators and possibly the standby ASI, have differed, leading to uncertainty and confusion.
"SPEED" as a support call from the PM usually means the PF is out of tolerance. But to what extent and in what direction - too fast or too slow? Perhaps "Speed fast" or "Speed slow" would be more precise - especially if an erroneous airspeed indication was the problem. A quick glance at the third ASI as the umpire, may help clarify things promptly -assuming that ASI is unaffected because of its different information source. This is the reason for the third ADI - to act as umpire.
A call of "SPEED FAST" from the PM would hopefully immediately prompt a query from the PF, if his own ASI was indicating correctly to his eyes.
In the early days of the 737-100/200, Boeing recommended (for the approach and landing case) the airspeed support call be based upon the planned Vref speed. For example "Vref plus 15." This policy was based upon the fact that anything faster than Vref at the threshold would extend the landing distance. The current limit of Vref plus 20 knots is till the upper figure beyond which the potential for an over-run beyond the scheduled landing distance becomes serious.
A planned approach speed of Vref plus 20 knots (this would generally mean headwind component and gust additives combined) would not be subject to a out of tolerance support call if the airspeed was within company tolerance. Nevertheless a heightened sense of speed awareness engendered by reference to Vref would surely be good airmanship - particularly if runway length limited or wet surface.
Thus, two knots over the additives doesn't sound very much - but a support call of "Vref Plus 22 knots" puts a whole new urgency into the support call. A call of "SPEED" by itself becomes meaningless.
Many years ago, an airline in Australia introduced a support call at 500 feet above airfield elevation, of airspeed deviation above Vref and rate of descent. This was intended to remind the crew of the lower limit of stabilisation on final, whether IMC or visual. A typical call by the PM would be "500 feet - Vref plus 12 - Sink 800." The call emphasised the airspeed above Vref - not the airspeed above the Vref plus additives. "Bug plus 2" sounds positively benign in meaning, when compared with "Vref plus 22"
Regardless of company policy on speed tolerances before a warning (support) call is warranted, "SPEED FAST" or "SPEED SLOW" is more precise that the one word "SPEED." It also has the added advantage of quickly picking the onset of erroneous airspeed indications.
Join Date: Jun 2000
Location: last time I looked I was still here.
Posts: 4,507
Likes: 0
Received 0 Likes
on
0 Posts
2 comments to a good question.
1. Boeing have just introduced a new EGPWS call on the NG. It is combines "Speed" & "Low". This is unambiguous and is after Turkish Airlines Schiphol. Perhaps this has been done without altering the FCTM.
2. When giving training I emphasise the correct Power/Speed/Att. for whatever the configuration and task in hand. Once, when LT to a student I had not seen in the sim I noticed he was not scanning the N1% on finals. At 800' the speed was correct but the N1% too low. As the speed dribbled lower there was not reaction from PF. He was oblivious. I waited and at Vapp -3 I called "power". The speed was within limits, but approaching the lower limit and the root cause was power. I expected PF to scan the N1% and realise the error. Nope; without looking he reduced the power even more, quickly followed by my hands pushing the T/L's up. I realised my mistake was to not be precise in my call. If I'd called "power too low" or "increase thrust" I hope PF would have reacted correctly. Being a student he reacted without thinking or scanning, and it was wrong. It was not a time, as with other parameters during a relaxed moment in LT, to ask " what do you think about the power setting", but give a precise instruction.
Thus I'd tend to agree with the Centaurus's idea.
1. Boeing have just introduced a new EGPWS call on the NG. It is combines "Speed" & "Low". This is unambiguous and is after Turkish Airlines Schiphol. Perhaps this has been done without altering the FCTM.
2. When giving training I emphasise the correct Power/Speed/Att. for whatever the configuration and task in hand. Once, when LT to a student I had not seen in the sim I noticed he was not scanning the N1% on finals. At 800' the speed was correct but the N1% too low. As the speed dribbled lower there was not reaction from PF. He was oblivious. I waited and at Vapp -3 I called "power". The speed was within limits, but approaching the lower limit and the root cause was power. I expected PF to scan the N1% and realise the error. Nope; without looking he reduced the power even more, quickly followed by my hands pushing the T/L's up. I realised my mistake was to not be precise in my call. If I'd called "power too low" or "increase thrust" I hope PF would have reacted correctly. Being a student he reacted without thinking or scanning, and it was wrong. It was not a time, as with other parameters during a relaxed moment in LT, to ask " what do you think about the power setting", but give a precise instruction.
Thus I'd tend to agree with the Centaurus's idea.
Join Date: May 2000
Location: Seattle
Posts: 3,196
Likes: 0
Received 0 Likes
on
0 Posts
You think a GPWS call of "speed & low" is unambiguous?!? Is my speed low or my altitude low?!? Should I raise or lower the nose? Sorry, but it doesn't make good sense to me...
Join Date: Oct 2005
Location: USA
Posts: 3,218
Likes: 0
Received 0 Likes
on
0 Posts
We use the deviation call "airspeed." I don't like "speed" because it is too vague. "Speed" could be vertical speed or airspeed.
If the pilot flying is aware of his status at all, he knows he's deviating. The call is a reminder that not only is he deviating, but that he needs to correct. We use the call "Airspeed" followed by the response "correcting." The only exception to that response might be a circumstance in which a gross error occurs between crewmember's airspeed indicators, in which case the pilot flying should really say something about his or her speed. I've seen that happen a few times over the years in different aircraft.
We only use "airspeed" as a deviation call, except for one time during the takeoff, when the same call is used to denote airspeed-alive, or that the first indication of airspeed indicator movement has happened. The call is intended only to draw attention to the airspeed indicator. The attitude display has a fast/slow indicator for the airspeed reference bug, and will give an immediate indication of the airspeed.
Our standard call is intended to be made if airspeed if 10 knots fast, or if it's below "bug" speed (the intended speed for a particular phase of flight and configuration). It's most commonly expected during an approach, but could be heard in cruise under an unusual circumstance. A drop in speed due to unusual wave action, shear, or an autothrottle problem, for example.
During the approach, we have two calls at 1000' and 500' above touchdown zone elevation that don't involve airspeed, but altitude and pitch. The flight engineer will add the vertical speed and declare the status of any instrument flags. When the word speed is used by the engineer in that event, he will specify "vertical speed" in order that it not be confused with airspeed. If the flight engineer notes an airspeed discrepancy or outside the boundaries of the deviation criteria, he may also call "airspeed."
While I have met check airman who will jump down someone's throat for any extra verbiage (such as "thanks" or "please"), most are quite willing to add a quick "watch your airspeed," or "you're fast," or "don't get slow." Those are non-standard, but fortunately most have enough common sense to do the same as we used to do with police radio: when in doubt, fall back to plain English. It still works.
Insofar as standard call-outs, I think "airspeed" works, because the call is only intended to remind the pilot flying of what he should already know. If there's any ambiguity, or room for misunderstanding, then the person making the call should clarify that in plain English, or the person flying should seek clarification. While "airspeed" works, I agree that it could also be improved. "Airspeed high" or "airspeed low" takes very little extra time and conveys a lot more information.
We do have various deviation calls that are also equally neutral, which might be improved. "Glideslope" for example, could be improved with "above glideslope" or "below glideslope."
If the pilot flying is aware of his status at all, he knows he's deviating. The call is a reminder that not only is he deviating, but that he needs to correct. We use the call "Airspeed" followed by the response "correcting." The only exception to that response might be a circumstance in which a gross error occurs between crewmember's airspeed indicators, in which case the pilot flying should really say something about his or her speed. I've seen that happen a few times over the years in different aircraft.
We only use "airspeed" as a deviation call, except for one time during the takeoff, when the same call is used to denote airspeed-alive, or that the first indication of airspeed indicator movement has happened. The call is intended only to draw attention to the airspeed indicator. The attitude display has a fast/slow indicator for the airspeed reference bug, and will give an immediate indication of the airspeed.
Our standard call is intended to be made if airspeed if 10 knots fast, or if it's below "bug" speed (the intended speed for a particular phase of flight and configuration). It's most commonly expected during an approach, but could be heard in cruise under an unusual circumstance. A drop in speed due to unusual wave action, shear, or an autothrottle problem, for example.
During the approach, we have two calls at 1000' and 500' above touchdown zone elevation that don't involve airspeed, but altitude and pitch. The flight engineer will add the vertical speed and declare the status of any instrument flags. When the word speed is used by the engineer in that event, he will specify "vertical speed" in order that it not be confused with airspeed. If the flight engineer notes an airspeed discrepancy or outside the boundaries of the deviation criteria, he may also call "airspeed."
While I have met check airman who will jump down someone's throat for any extra verbiage (such as "thanks" or "please"), most are quite willing to add a quick "watch your airspeed," or "you're fast," or "don't get slow." Those are non-standard, but fortunately most have enough common sense to do the same as we used to do with police radio: when in doubt, fall back to plain English. It still works.
Insofar as standard call-outs, I think "airspeed" works, because the call is only intended to remind the pilot flying of what he should already know. If there's any ambiguity, or room for misunderstanding, then the person making the call should clarify that in plain English, or the person flying should seek clarification. While "airspeed" works, I agree that it could also be improved. "Airspeed high" or "airspeed low" takes very little extra time and conveys a lot more information.
We do have various deviation calls that are also equally neutral, which might be improved. "Glideslope" for example, could be improved with "above glideslope" or "below glideslope."
Join Date: Oct 2007
Location: fort sheridan, il
Posts: 1,656
Likes: 0
Received 0 Likes
on
0 Posts
whatever way you do it...everyone at the airline should do it the same way.
speed means LOOK AT YOUR AIRSPEED INDICATOR
and most always means too slow.
the airplane makes too much noise if its going too fast, doesn't it????? (except douglas twin jets)....very quiet.
speed means LOOK AT YOUR AIRSPEED INDICATOR
and most always means too slow.
the airplane makes too much noise if its going too fast, doesn't it????? (except douglas twin jets)....very quiet.
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 4,499
Likes: 0
Received 0 Likes
on
0 Posts
You think a GPWS call of "speed & low" is unambiguous?!? Is my speed low or my altitude low?!? Should I raise or lower the nose? Sorry, but it doesn't make good sense to me...
Join Date: Oct 2005
Location: USA
Posts: 3,218
Likes: 0
Received 0 Likes
on
0 Posts
the airplane makes too much noise if its going too fast, doesn't it?????
Are you suggesting we listen for changes in wind noise, rather than make standard call-outs?
"I'm just going too be brief because this is a very active time in my personal life...
but it is incumbent upon the both pilots to be responsible for knowing and verifying the significant parameters once a call has been made whether or not the call seems vague.
for instance, lets assume the PNF calls out---*sshole instead of the more appropriate phrasing of either 'Airspeed', Vertical Speed,' Sink Rate etc...then it is still the responsibility of the NPF, HP...etc... to verify All significant parameters on HIS/HER INSTRUMENTS!!!!
Anyone who can't do that, will have, in past employment failed an instrument examination in an SEP PT...
but it is incumbent upon the both pilots to be responsible for knowing and verifying the significant parameters once a call has been made whether or not the call seems vague.
for instance, lets assume the PNF calls out---*sshole instead of the more appropriate phrasing of either 'Airspeed', Vertical Speed,' Sink Rate etc...then it is still the responsibility of the NPF, HP...etc... to verify All significant parameters on HIS/HER INSTRUMENTS!!!!
Anyone who can't do that, will have, in past employment failed an instrument examination in an SEP PT...
