"Flyaway" Call
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"Flyaway" Call
The company I work for, has in its SOP's, a call of "Flyaway". This call is to be announced by the PF at some point after take-off to confirm to the PNF his intentions. We are to use it at both runway and offshore departures.
Here is where the confusion comes in.....do you call when you intend to at least try to "flyaway" (not ditch when offshore) or when you think the a/c has the alt/airspeed to continue flight.
Who else out there uses this call? What is your understanding/opinion of this call?
Let the games begin!
Here is where the confusion comes in.....do you call when you intend to at least try to "flyaway" (not ditch when offshore) or when you think the a/c has the alt/airspeed to continue flight.
Who else out there uses this call? What is your understanding/opinion of this call?
Let the games begin!
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Outwest:
I note from your profile that, in spite of your handle, you are an S61 Offshore Captain - that information is used in this post.
Firstly, a question; if this is in your company SOPs, isn't the best place for information/guidance the training department? However, you are seeking a discussion so here goes.
Onshore and offshore departures are totally different and they should be treated as such.
The S61 is quite capable of PC1 onshore from a runway, even at 20,500lbs, and the procedures are contained in the RFM (well at least in European ones). When flying the Cat A procedure, most calls belong to the PNF and reactions come from the PF - once the TDP is called, the PF applies the cyclic input and the helicopter becomes 'go' oriented; if an engine fails before TDP both know that the rejected take-off is the action required; there should be no confusion.
If there is no Cat A procedure in the RFM and PC2 is being flown, the requirement will be for the second segment climb performance (150ft/min at 1000ft above the take-off elevation at Vy). In the absence of any data (or procedures in the RFM or OM), there is no way that the point at which the helicopter becomes ‘go’ oriented can be calculated and any call will be a guess - 35kts can be used as a rule-of-thumb as this is usually quite close to Vstayup. What normally applies is that the Captain will chose a point in relation to the distance along the runway at which he/she judges that a return to the runway would not be possible; at that point a signal of intentions could be given - it could be ‘flyaway’ or any call used in SOPs. Complications will exist if an IFR departure is being flown; cloud should not be entered before Vmini, at which time the helicopter will be ‘go’ oriented and might be called by the PNF. All of this requires a pre-take-off brief to ensure that both crew members are oriented to the same profile/procedure/calls.
Offshore it is totally different and it does rather depend on the profiles flown - the take-off mass should still be given by the second segment climb. In the North Sea, the procedures call for a towering take-off with a Rotation Point (RP) at 20ft; from a low hover, the appropriate collective input is applied and when the PNF calls the height, the PF applies the cyclic input and calls ‘going’ or whatever is in the SOPs - RP indicates the last time at which a re-landing on the deck can be contemplated. At the point of rotation, unless the wind is in excess of 35kts or the aircraft is very light, the helicopter becomes exposed to a deck-edge strike followed immediately by exposure to a ditching. In the absence of any data (or procedures in the RFM or OM), there is no way that the point at which a continued take-off can be calculated and any further call will be a guess - as above 35kts can be used as a rule-of-thumb as this is usually quite close to Vstayup.
The latest types (S76C+, S92, EC225, AB139 - and hopefully the small twins) rectify this lack of offshore data and will provide Enhance PC2 (PC2e) procedures together with data - at that time all calls will be associated with procedures and data contained in the RFMs and be deterministic.
I note from your profile that, in spite of your handle, you are an S61 Offshore Captain - that information is used in this post.
Firstly, a question; if this is in your company SOPs, isn't the best place for information/guidance the training department? However, you are seeking a discussion so here goes.
Onshore and offshore departures are totally different and they should be treated as such.
The S61 is quite capable of PC1 onshore from a runway, even at 20,500lbs, and the procedures are contained in the RFM (well at least in European ones). When flying the Cat A procedure, most calls belong to the PNF and reactions come from the PF - once the TDP is called, the PF applies the cyclic input and the helicopter becomes 'go' oriented; if an engine fails before TDP both know that the rejected take-off is the action required; there should be no confusion.
If there is no Cat A procedure in the RFM and PC2 is being flown, the requirement will be for the second segment climb performance (150ft/min at 1000ft above the take-off elevation at Vy). In the absence of any data (or procedures in the RFM or OM), there is no way that the point at which the helicopter becomes ‘go’ oriented can be calculated and any call will be a guess - 35kts can be used as a rule-of-thumb as this is usually quite close to Vstayup. What normally applies is that the Captain will chose a point in relation to the distance along the runway at which he/she judges that a return to the runway would not be possible; at that point a signal of intentions could be given - it could be ‘flyaway’ or any call used in SOPs. Complications will exist if an IFR departure is being flown; cloud should not be entered before Vmini, at which time the helicopter will be ‘go’ oriented and might be called by the PNF. All of this requires a pre-take-off brief to ensure that both crew members are oriented to the same profile/procedure/calls.
Offshore it is totally different and it does rather depend on the profiles flown - the take-off mass should still be given by the second segment climb. In the North Sea, the procedures call for a towering take-off with a Rotation Point (RP) at 20ft; from a low hover, the appropriate collective input is applied and when the PNF calls the height, the PF applies the cyclic input and calls ‘going’ or whatever is in the SOPs - RP indicates the last time at which a re-landing on the deck can be contemplated. At the point of rotation, unless the wind is in excess of 35kts or the aircraft is very light, the helicopter becomes exposed to a deck-edge strike followed immediately by exposure to a ditching. In the absence of any data (or procedures in the RFM or OM), there is no way that the point at which a continued take-off can be calculated and any further call will be a guess - as above 35kts can be used as a rule-of-thumb as this is usually quite close to Vstayup.
The latest types (S76C+, S92, EC225, AB139 - and hopefully the small twins) rectify this lack of offshore data and will provide Enhance PC2 (PC2e) procedures together with data - at that time all calls will be associated with procedures and data contained in the RFMs and be deterministic.
Great post mars.
I am not really sure what your confusion is here outwest, but I think you are asking if the call should be made when able to fly away Vs when you are no longer considering a reject. I am with mars, the call should be made only when there is no longer room to reject on an open area, even though you may have attained flyaway speeds (Vstayup) alot earlier and I remember a detailed thread on this very question before.
I think terminology is often an obstacle to understanding or clearly communicating the situation, and "flyaway" is one such term (right up there with CDP which I was pleased to see Mars avoid). I suggest "committed" as a substitute for flyaway, followed by what you are committed to. This term can be used in both PC1 cat A and PC2 Cat B ops and allows clear and decisive communications of intent to the crew.
For example, on the CAT A helideck departures, "Committed" would be lowering the nose. On the onshore runway departure, it would be "committed to flyaway" when passing the point at which a rejected landing is no longer possible. On the CatB stuff, you use it very similarly, but in a more complex fashion. Lets say you are coming off a hospital rooftop Cat B with a nice big oval across the road from the hospital. As you get sufficient hieght to clear the roof, you lower the nose and call "committed to the oval". As you trade altitude for airspeed and attain Vstayup with little chance of a succesful reject into the oval, then you call "committed to flyaway". Clarity is the goal.
The term can then also be applied to the landing phase as easily, which flyaway cannot. The call at LDP can be "committed" to indicate committed to land, or lets say in the hospital helipad scenario, you can call committed to the oval first, and then when you are low enough and close enough to the pad to safely land, call c"ommitted to the pad."
The good thing is it is decisive, unambiguous, and can be used as a standard phrase during both TO and Landing.
I am not really sure what your confusion is here outwest, but I think you are asking if the call should be made when able to fly away Vs when you are no longer considering a reject. I am with mars, the call should be made only when there is no longer room to reject on an open area, even though you may have attained flyaway speeds (Vstayup) alot earlier and I remember a detailed thread on this very question before.
I think terminology is often an obstacle to understanding or clearly communicating the situation, and "flyaway" is one such term (right up there with CDP which I was pleased to see Mars avoid). I suggest "committed" as a substitute for flyaway, followed by what you are committed to. This term can be used in both PC1 cat A and PC2 Cat B ops and allows clear and decisive communications of intent to the crew.
For example, on the CAT A helideck departures, "Committed" would be lowering the nose. On the onshore runway departure, it would be "committed to flyaway" when passing the point at which a rejected landing is no longer possible. On the CatB stuff, you use it very similarly, but in a more complex fashion. Lets say you are coming off a hospital rooftop Cat B with a nice big oval across the road from the hospital. As you get sufficient hieght to clear the roof, you lower the nose and call "committed to the oval". As you trade altitude for airspeed and attain Vstayup with little chance of a succesful reject into the oval, then you call "committed to flyaway". Clarity is the goal.
The term can then also be applied to the landing phase as easily, which flyaway cannot. The call at LDP can be "committed" to indicate committed to land, or lets say in the hospital helipad scenario, you can call committed to the oval first, and then when you are low enough and close enough to the pad to safely land, call c"ommitted to the pad."
The good thing is it is decisive, unambiguous, and can be used as a standard phrase during both TO and Landing.
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Mars, not sure what you mean by
but my profile is correct.
Obviously, but they seem as confused as I am. Ask one and they have an interpretation, ask another and they disagree. That’s why I’m looking for outside input.
Exactly. Our SOP does not differentiate between the 2 when it comes to this call.
My original post was made in haste; I will try and clarify what I’m looking for.
Firstly, the call onshore (runway) is not in contention, it is offshore where all the confusion lies, so that is what I will try to clarify.
The gist of the SOP (can’t post the SOP, as it may violate policy), is that the PF is to call when he “feels” the a/c (this call is not type specific, applies to all a/c in the fleet) will continue flight in the event of an OEI. The intent of this SOP is so that the PNF is on the same page as the PF.
As you say,
So, if a donk fails just after forward cyclic input, do you do everything in your power (drop down, etc.) to try and get enough flying speed (35kts?) to stay out of the water, or just ditch?
I think you would be surprised at the answers to that question when raised in a room full of pilots. Some said if they had not called “flyaway”, they were ditching, not even attempting to get flying speed, others said they would try and then if at say 25 feet with rpm and airspeed decaying, they would simply declare “ditching” and flare for touchdown. One even said that he would try to flyaway but blow the floats (S76) anyway!!!
So what I am looking for is input from others to see if this is a call used by other operators.
Helmet fire, as stated above the confusion is when the rejected area is hostile. Of course if you have a safe reject area, that is where you will go if not assured flyaway.
in spite of your handle
Firstly, a question; if this is in your company SOPs, isn't the best place for information/guidance the training department?
Onshore and offshore departures are totally different and they should be treated as such.
My original post was made in haste; I will try and clarify what I’m looking for.
Firstly, the call onshore (runway) is not in contention, it is offshore where all the confusion lies, so that is what I will try to clarify.
The gist of the SOP (can’t post the SOP, as it may violate policy), is that the PF is to call when he “feels” the a/c (this call is not type specific, applies to all a/c in the fleet) will continue flight in the event of an OEI. The intent of this SOP is so that the PNF is on the same page as the PF.
As you say,
In the absence of any data (or procedures in the RFM or OM), there is no way that the point at which the helicopter becomes ‘go’ oriented can be calculated and any call will be a guess - 35kts can be used as a rule-of-thumb as this is usually quite close to Vstayup.
I think you would be surprised at the answers to that question when raised in a room full of pilots. Some said if they had not called “flyaway”, they were ditching, not even attempting to get flying speed, others said they would try and then if at say 25 feet with rpm and airspeed decaying, they would simply declare “ditching” and flare for touchdown. One even said that he would try to flyaway but blow the floats (S76) anyway!!!
So what I am looking for is input from others to see if this is a call used by other operators.
Helmet fire, as stated above the confusion is when the rejected area is hostile. Of course if you have a safe reject area, that is where you will go if not assured flyaway.
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Yes Phil I am indeed from the company you think. I know what the definition says, but as i said for every guy you ask, you get a different opinion. IMHO, SOP's, OPS Manuals etc. have one primary function, to enhance safety. This call not only does not do that, I believe it is actually detrimental. Again, my opinion and that is why I want input from others around the world.
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Outwest:
Someone in the company must own the knowledge that led to proposal to amend the SOPs; that person must have had a conceptual view when the procedures were revised to include the 'flyaway' call - he/she would be my first port of call.
As I said in my previous post (for the S61), if the engine fails immediately after the cyclic input, (unless you have a strong wind or are extremely light) there is a high probability that the helicopter will strike the deck-edge - this first phase exposure lasts for about a couple of seconds; following that, and depending upon the height of the helideck, there will be a period during which a ditching will be inevitable - this second phase also lasts for about a couple of seconds.
Drop down is sensitive to the Pitch Attitude (PA) adopted at rotation - in light winds, the optimum PA will be about 20 degrees; in strong winds the same PA will increase the drop down by about 75ft - my point, there needs to be a pre-considered strategy; diving to achieve 35kts could increase the drop down and result in a ditching. Deck edge clearance is also sensitive to PA but will not produce the same detrimental effect if the light wind PA is flown in strong winds. My point about the rule-of-thumb was that it probably marks the end of exposure - nothing more - but at least at that point both members become go oriented and ditching drills can be set out-of-mind.
During an engine failure after the RP, the decision to continue the takeoff or conduct a ditching depends upon the airspeed and/or available dropdown at the Engine Failure Point (EFP). If the helicopter is in the second phase exposure (to ditching), as the aircraft approaches 50 ft AGL the pilot should raise the nose. If the rate of descent is stopped prior to 50 ft AGL, the takeoff should be continued. If the rate of descent is not stopped prior to 50 ft AGL, a ditching should be accomplished.
It is difficult to be more precise than that unless data exists and the take-off mass has been adjusted for drop down. If such data exists, the procedure becomes deterministic and only the RP has to be called.
Providing your company can resolve the issues, the introduction of the call will assist with crew coordination but it must be meaningful. As Helmet fire indicated, 'committed' can be used in the landing phase - this has real meaning as it ends the option to go-around (or ditching if that is the only/best option). The committal point should be set at the last point at which both options exist. For take-off, 'going' is a good call as it indicates (in the absence of physical cues) that the PF has input cyclic. Later calls are problematic as they signify nothing unless they are set to Vstayup or some other positive point.
Someone in the company must own the knowledge that led to proposal to amend the SOPs; that person must have had a conceptual view when the procedures were revised to include the 'flyaway' call - he/she would be my first port of call.
As I said in my previous post (for the S61), if the engine fails immediately after the cyclic input, (unless you have a strong wind or are extremely light) there is a high probability that the helicopter will strike the deck-edge - this first phase exposure lasts for about a couple of seconds; following that, and depending upon the height of the helideck, there will be a period during which a ditching will be inevitable - this second phase also lasts for about a couple of seconds.
Drop down is sensitive to the Pitch Attitude (PA) adopted at rotation - in light winds, the optimum PA will be about 20 degrees; in strong winds the same PA will increase the drop down by about 75ft - my point, there needs to be a pre-considered strategy; diving to achieve 35kts could increase the drop down and result in a ditching. Deck edge clearance is also sensitive to PA but will not produce the same detrimental effect if the light wind PA is flown in strong winds. My point about the rule-of-thumb was that it probably marks the end of exposure - nothing more - but at least at that point both members become go oriented and ditching drills can be set out-of-mind.
During an engine failure after the RP, the decision to continue the takeoff or conduct a ditching depends upon the airspeed and/or available dropdown at the Engine Failure Point (EFP). If the helicopter is in the second phase exposure (to ditching), as the aircraft approaches 50 ft AGL the pilot should raise the nose. If the rate of descent is stopped prior to 50 ft AGL, the takeoff should be continued. If the rate of descent is not stopped prior to 50 ft AGL, a ditching should be accomplished.
It is difficult to be more precise than that unless data exists and the take-off mass has been adjusted for drop down. If such data exists, the procedure becomes deterministic and only the RP has to be called.
Providing your company can resolve the issues, the introduction of the call will assist with crew coordination but it must be meaningful. As Helmet fire indicated, 'committed' can be used in the landing phase - this has real meaning as it ends the option to go-around (or ditching if that is the only/best option). The committal point should be set at the last point at which both options exist. For take-off, 'going' is a good call as it indicates (in the absence of physical cues) that the PF has input cyclic. Later calls are problematic as they signify nothing unless they are set to Vstayup or some other positive point.
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Mars, I agree completely with your comments/observations about pitch angle etc affecting the whole scenerio.
I failed to say we do have a "rotating" call at forward cyclic input. I agree with this call, it is the "flyaway" call that I'm against.
For landing we do have a "committed" call.
Well it has taken a while, but I believe that is the opinion I was after, thank you.
On a slightly different note, what are your thoughts on the landing briefing offshore? The gist of ours is along the lines of " this is a left seat landing with a right overshoot. Any problems prior to the committed call, I will overshoot to the right. etc, etc.
I have questioned different pilots on the "any problems" part. Any problems???? A chip light? a Fire light? A low fuel light? A hyd/control problem?
again, looking for input/comments.
For take-off, 'going' is a good call as it indicates (in the absence of physical cues) that the PF has input cyclic.
For landing we do have a "committed" call.
Later calls are problematic as they signify nothing unless they are set to Vstayup or some other positive point.
On a slightly different note, what are your thoughts on the landing briefing offshore? The gist of ours is along the lines of " this is a left seat landing with a right overshoot. Any problems prior to the committed call, I will overshoot to the right. etc, etc.
I have questioned different pilots on the "any problems" part. Any problems???? A chip light? a Fire light? A low fuel light? A hyd/control problem?
again, looking for input/comments.
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Safe Single Engine Speed: What is SAFE?
A group of us are developing and ratifying SOPs for a heavy twin helo. In discussing non-Cat A departure and arrival procedures, there is a difference of opinion as to what speeds the PM should call during transition. Historically we have called Safe Single Engine Speed (SSES), but on a new machine we now have to option of deriving a SSES based on max continuous power, 2 min or 30 sec contingency (don't know exactly what the legacy numbers were based upon as the technical data is weak to nonexistent).
So the question is: What constitutes SAFE?: Sustained flight?; max climb?; immediate obstacle clearance?; accel to Vy?.....
Some communities (and the OEM) use 'Stay-Up Speed' which is based on max continuous power OEI. This will only allow sustained level flight. Equally so, flight at 30s or 2 min 'Safe Single' only assures level flight (for the next 30s or 2 min). In either case, should a climb be required, one needs to accelerate to a speed closer to Vy.
Then, is there any value in calling the lower 30s SSES? It would assist the PFs SA, but the likely result is contining to accel to Vy anyways. Does the call provided any value over waiting another second or to until, say, Vtoss or Stay-Up?
I'd be curious to hear what other communities do, and specifically the reasons why.
So the question is: What constitutes SAFE?: Sustained flight?; max climb?; immediate obstacle clearance?; accel to Vy?.....
Some communities (and the OEM) use 'Stay-Up Speed' which is based on max continuous power OEI. This will only allow sustained level flight. Equally so, flight at 30s or 2 min 'Safe Single' only assures level flight (for the next 30s or 2 min). In either case, should a climb be required, one needs to accelerate to a speed closer to Vy.
Then, is there any value in calling the lower 30s SSES? It would assist the PFs SA, but the likely result is contining to accel to Vy anyways. Does the call provided any value over waiting another second or to until, say, Vtoss or Stay-Up?
I'd be curious to hear what other communities do, and specifically the reasons why.
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I always liked Vbroc. That meaning the airspeed at which the aircraft will achieve the maximum rate of climb for any given weight. Depending upon the weight of the aircraft it might actually be a negative rate of climb but it would be the best achievable Rate of Climb. Ideally, the Aircraft weight would be restricted to allow for a positive rate of climb if one is concerned with continuing flight following an engine failure.
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"Just a pilot"
What's the intent of the call?
Are you to fly to another landing point after an engine failure? If so, then your weight and power planning is done to enable that, I'd call the VX/VYse.
If you can't recover to another landing point SE, do you need a decision point callout to signify the speed that keeps you from an unsustainable SE departure- isn't that Vtoss?
If you can't recover to another landing point SE, do you need a decision point callout to signify the speed that keeps you from an unsustainable SE departure- isn't that Vtoss?
Helosammy - I know we don't operate to civilian performance categories but in the Sea King (Brit MilSAR) the assumption is that Max contingency power (30 secs) is what will be used as you are trying not to crash the aircraft and will use as much power as is available from the remaining engine.
Our Operating Data Manual allows us to calculate Min SELF (minimum single engine speed for level flight) based on that max con power.
We have the ability to practice all sorts of flyaway manoeuvres in the aircraft as we can select an engine into manual control, fix a sensible power to avoid exceeding limitations and then 'fail' the other engine.
The earlier conversations in this thread regarding 20 degrees nose down are probably based on the S61 RFM for worst case but are excessive for real world ops if the S61 flys anything like the Sea King - you trade far too much height off to get your speed at 20 degrees, the only time I would use that much is if I was hovering downwind. Our data is based on the actual aircraft performance and not simulations.
Our flyaway call is an assessment of the aircraft's ability to continue flight in the event on an engine failure - if you call flyaway with lots of tarmac ahead of you, the sensible thing would be to land - not an indication of intent by the pilot.
Our Operating Data Manual allows us to calculate Min SELF (minimum single engine speed for level flight) based on that max con power.
We have the ability to practice all sorts of flyaway manoeuvres in the aircraft as we can select an engine into manual control, fix a sensible power to avoid exceeding limitations and then 'fail' the other engine.
The earlier conversations in this thread regarding 20 degrees nose down are probably based on the S61 RFM for worst case but are excessive for real world ops if the S61 flys anything like the Sea King - you trade far too much height off to get your speed at 20 degrees, the only time I would use that much is if I was hovering downwind. Our data is based on the actual aircraft performance and not simulations.
Our flyaway call is an assessment of the aircraft's ability to continue flight in the event on an engine failure - if you call flyaway with lots of tarmac ahead of you, the sensible thing would be to land - not an indication of intent by the pilot.
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In my initial post I was purposely vague as to the nature of our operation in order to generate unbiased discussion. We are, in fact, military making the transistion to a new machine with more civilian-like ways in line with OEM direction. However, the SOPs remain ours to direct (to some extent). So...
Quote:
"Later calls are problematic as they signify nothing unless they are set to Vstayup or some other positive point."
Aye, there's the rub. My real question then is: what value is there in calling any speeds between 'Airspeed's alive' and Vy?
Each will aid the PF's SA, but what value do they provide?:
Safe-Single or Stay-up based on 30s OEI: only assures level flight for the next 30 sec, but allows the PF to know he's in the regime where he can choose to flyout using contingency power to achieve Vtoss or Vy;
Stay-up or SSES based on Max Continuous power: sustained level flight with contingency power available to climb or accel to Vtoss or Vy;
Vtoss: 100 fpm climb is assured and a better angle of climb; or
Vy: flying and climbing.
The OEM Stay-Up charts are based on OEI max continous, and some believe OEI 30s is more realistic to use.
Thoughts?
Quote:
"Later calls are problematic as they signify nothing unless they are set to Vstayup or some other positive point."
Aye, there's the rub. My real question then is: what value is there in calling any speeds between 'Airspeed's alive' and Vy?
Each will aid the PF's SA, but what value do they provide?:
Safe-Single or Stay-up based on 30s OEI: only assures level flight for the next 30 sec, but allows the PF to know he's in the regime where he can choose to flyout using contingency power to achieve Vtoss or Vy;
Stay-up or SSES based on Max Continuous power: sustained level flight with contingency power available to climb or accel to Vtoss or Vy;
Vtoss: 100 fpm climb is assured and a better angle of climb; or
Vy: flying and climbing.
The OEM Stay-Up charts are based on OEI max continous, and some believe OEI 30s is more realistic to use.
Thoughts?
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Helosammy,
If I'm not making too many assumptions from your hints of your location, why not make contact with some of the retired Canadian military pilots who have been operating the S92 commercially in your locale for years.
Your definitions above are roughly correct, but you're definitely confusing your thoughts by including what you call stay-up at OEI MCP in a discussion about take off calls. OEI MCP at a certain altitude, allows you to calculate the stay-up weight at that altitude. So, a primary example of its use would be calculating your maximum weight at a minimum IFR cruising altitude. The only relation it has to take off performance, is that a limitation on cruising altitude weight, may also dictate that you need to take off at a low weight to achieve what's required at altitude.
Vtoss is as your definition, it's the speed that will guarantee you a 100fpm climb with the gear down. That is, it's the speed that will get you climbing clear of runway environment obstacles. That's why it only needs to be for 2 mins.
Vy, we all know. It's defined as being at MCP in formal take off performance planning, because it needs to get you to 1000ft above the take off surface and that will take several minutes at the defined 150fpm.
(BTW, if you really want to amuse/ frighten yourself some day, think about the horizontal distances you will travel, if you are climbing at the minimum guaranteed rate of climb in the Vtoss and VY sectors. It works out in the order of 2 miles to get you to 200ft and a further 7 or so, to get you to 1000ft. It sort of emphasizes nicely that this performance planning is for a runway environment)
What you're calling safe- single 30secs, aligns with what full blown commercial ops call Vtdp. That will define a airspeed, AT A CERTAIN TAKE OFF WEIGHT, at which you can accelerate towards Vtoss and then start aviating as your god and squadron commander planned you to. For your military ops, being aware of formal Vtdps and associated take off weights is going to give you a good " guess" at which point to call fly-away. If you call too early at a high weight you're not going to have the performance to accelerate and achieve Vtoss.
True commercial operations not only take the ability to fly away into account, but also the ability to stop on the runway surface ahead, if a engine is lost before Vtdp. The S92 RFM is a bit weak on that calculation, effectively you have to use your TO weight to calculate Vtdp, the combination of which gives you the runway length required for take off. Of course that's all a bit backwards to the real world, so what you end up doing is several circular calculations to give you a take off weight that relates to your actual runway length.
In simple terms. For high weight you need a higher Vtdp and hence Vtoss before the thing will fly. But that high Vtdp may not allow you to stop on the runway remaining, so in that case you would have to reduce your weight to lower your Vtdp.
If I'm not making too many assumptions from your hints of your location, why not make contact with some of the retired Canadian military pilots who have been operating the S92 commercially in your locale for years.
Your definitions above are roughly correct, but you're definitely confusing your thoughts by including what you call stay-up at OEI MCP in a discussion about take off calls. OEI MCP at a certain altitude, allows you to calculate the stay-up weight at that altitude. So, a primary example of its use would be calculating your maximum weight at a minimum IFR cruising altitude. The only relation it has to take off performance, is that a limitation on cruising altitude weight, may also dictate that you need to take off at a low weight to achieve what's required at altitude.
Vtoss is as your definition, it's the speed that will guarantee you a 100fpm climb with the gear down. That is, it's the speed that will get you climbing clear of runway environment obstacles. That's why it only needs to be for 2 mins.
Vy, we all know. It's defined as being at MCP in formal take off performance planning, because it needs to get you to 1000ft above the take off surface and that will take several minutes at the defined 150fpm.
(BTW, if you really want to amuse/ frighten yourself some day, think about the horizontal distances you will travel, if you are climbing at the minimum guaranteed rate of climb in the Vtoss and VY sectors. It works out in the order of 2 miles to get you to 200ft and a further 7 or so, to get you to 1000ft. It sort of emphasizes nicely that this performance planning is for a runway environment)
What you're calling safe- single 30secs, aligns with what full blown commercial ops call Vtdp. That will define a airspeed, AT A CERTAIN TAKE OFF WEIGHT, at which you can accelerate towards Vtoss and then start aviating as your god and squadron commander planned you to. For your military ops, being aware of formal Vtdps and associated take off weights is going to give you a good " guess" at which point to call fly-away. If you call too early at a high weight you're not going to have the performance to accelerate and achieve Vtoss.
True commercial operations not only take the ability to fly away into account, but also the ability to stop on the runway surface ahead, if a engine is lost before Vtdp. The S92 RFM is a bit weak on that calculation, effectively you have to use your TO weight to calculate Vtdp, the combination of which gives you the runway length required for take off. Of course that's all a bit backwards to the real world, so what you end up doing is several circular calculations to give you a take off weight that relates to your actual runway length.
In simple terms. For high weight you need a higher Vtdp and hence Vtoss before the thing will fly. But that high Vtdp may not allow you to stop on the runway remaining, so in that case you would have to reduce your weight to lower your Vtdp.
Last edited by inputshaft; 11th Jun 2014 at 02:24.
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Inputshaft, crab, devil mars, bob,
Thanks for your input. You've provided some great feedback and helped me confirm some areas of question. I largely concur with all your comments as they are inline with my experience.
Inputshaft; I have indeed been in contact with the ex-CF members, but am casting a larger net via this forum. I'm trying to gather as much knowledge and opinion as I can from sources that may not have been 'tainted' by 'how we always used to do it' so that I can facilitate the eventual discussion/debate from the most informed/prepared position.
Quote: "but, you're definitely confusing your thoughts by inlcuding what you call Stay-Up at OEI MCP in a discussion about take-off calls".
This is the crux of the issue. I don't want to get into too much detail because I'm not entirely sure that I won't be breeching and proprietary or trade restrictions. The OEM did not provide any safe-single charts, and our Project side has asked for some as that's 'what we've always done'. In return, the OEM gave us a Stay-Up speed chart based on OEI Max Cont. Some would argue we should call the speed based on 30s power. So here we are. One way or another something has to change; either what speed we call or what we call that speed.
Performance is not the issue. Cat A depatures are pretty black-and-white as far as expectations and definitions of V speeds and their meaning. It's the CRM particulars of Cat B departures that are in discussion. There's hesitance from some to flat-out adopt civilian Vtoss or TDP calls because it's just too different than what we've always done.
Mars; Quote: "isn't the best place for information/guidance the training department?" and "someone in the company must own the knowledge that led to the proposal to ammend the SOPs; that person must have the had the conceptual view when the procedures were revised..."
Extremely valid. I agree that going to the source should always be the first step in making change, however, right now we are becoming the ones who will have to answer future generations as to the decisions we make right now. Therefore, we had better know why we're making change.
Quote: "I think terminology is often an obstacle to understanding or clearly communicating the situation" and "the introduction of the call will assist with crew coordination but it must be meaningful".
Exactly. We are trying to ensure that we have a complete understanding of the terminology in use and that the calls we derive are consistent with their engineering background, and with the intentions and actions expected between PF and PM/PNF.
Crab; Quote: "if you call flyaway with lots of tarmac ahead of you, the sensible thing would be to land..."
I questioned this very issue when I flew with the RN. It's this sort of ambiguity and lack of defintion that I am trying to avoid.
You're discusions (all y-all's) have given me sufficient confirmation as well as direction for added research. We are at a point where we can lead positive change and are hoping to achieve the best we can. Again, thanks for your input.
Thanks for your input. You've provided some great feedback and helped me confirm some areas of question. I largely concur with all your comments as they are inline with my experience.
Inputshaft; I have indeed been in contact with the ex-CF members, but am casting a larger net via this forum. I'm trying to gather as much knowledge and opinion as I can from sources that may not have been 'tainted' by 'how we always used to do it' so that I can facilitate the eventual discussion/debate from the most informed/prepared position.
Quote: "but, you're definitely confusing your thoughts by inlcuding what you call Stay-Up at OEI MCP in a discussion about take-off calls".
This is the crux of the issue. I don't want to get into too much detail because I'm not entirely sure that I won't be breeching and proprietary or trade restrictions. The OEM did not provide any safe-single charts, and our Project side has asked for some as that's 'what we've always done'. In return, the OEM gave us a Stay-Up speed chart based on OEI Max Cont. Some would argue we should call the speed based on 30s power. So here we are. One way or another something has to change; either what speed we call or what we call that speed.
Performance is not the issue. Cat A depatures are pretty black-and-white as far as expectations and definitions of V speeds and their meaning. It's the CRM particulars of Cat B departures that are in discussion. There's hesitance from some to flat-out adopt civilian Vtoss or TDP calls because it's just too different than what we've always done.
Mars; Quote: "isn't the best place for information/guidance the training department?" and "someone in the company must own the knowledge that led to the proposal to ammend the SOPs; that person must have the had the conceptual view when the procedures were revised..."
Extremely valid. I agree that going to the source should always be the first step in making change, however, right now we are becoming the ones who will have to answer future generations as to the decisions we make right now. Therefore, we had better know why we're making change.
Quote: "I think terminology is often an obstacle to understanding or clearly communicating the situation" and "the introduction of the call will assist with crew coordination but it must be meaningful".
Exactly. We are trying to ensure that we have a complete understanding of the terminology in use and that the calls we derive are consistent with their engineering background, and with the intentions and actions expected between PF and PM/PNF.
Crab; Quote: "if you call flyaway with lots of tarmac ahead of you, the sensible thing would be to land..."
I questioned this very issue when I flew with the RN. It's this sort of ambiguity and lack of defintion that I am trying to avoid.
You're discusions (all y-all's) have given me sufficient confirmation as well as direction for added research. We are at a point where we can lead positive change and are hoping to achieve the best we can. Again, thanks for your input.
Crab; Quote: "if you call flyaway with lots of tarmac ahead of you, the sensible thing would be to land..."
I questioned this very issue when I flew with the RN. It's this sort of ambiguity and lack of defintion that I am trying to avoid.
I questioned this very issue when I flew with the RN. It's this sort of ambiguity and lack of defintion that I am trying to avoid.
Remember that PC1 and 2 (cat A and B) are all about not being sued if you crash with passengers aboard because the RFM guarantees that following the manufacturer's figures permits either safe landing or continued flight.
In mil flying, as you are aware, more flexibility is often required and a better awareness of what the aircraft will actually do - based on experience and training - offers a pilot flexibility of thought and action.
An example is of how much nose down to use to get to SSE - many RFM give worse-case examples in the region of 20 degrees nose down; that may be guaranteed to work in every case if you are above the specified height but in a lower level environment may be excessive and well beyond what is actually needed to get the aircraft safe.
