New Pilot Trying to Fly a Helicopter
ShyTorque,
Fishing? Not really, more that those of us who have such knowledge should be encouraging the use of the correct (and descriptive) terms when they are provided.
Helicopters are far more flexible than fixed wing and so require a different set of terms; yes, Take-off Decision Point (TDP) can be seen as similar (in the case of the ‘clear area’ profile which is analogous to runway operations) to V1 but that is the only case - even then TDP is also associated with a height (unlike V1 for fixed wing).
As can be seen from AC 29-2C there is no need “…to identify TDP by height and airspeed, since height alone or other factors may be more appropriate.” That makes the use of V1 under any circumstances questionable.
Similarly, take-off safety speed (Vtoss) should be used and not V2.
To relate any of these to hover taxi is not really appropriate as it is the combination of height and airspeed (and flight testing) which ensures that these ‘points’ are clear of the HV diagram - which always contains the low-level high-speed avoid area.
By the way, you never did identify the helicopter which has these terms.
Jim
Fishing? Not really, more that those of us who have such knowledge should be encouraging the use of the correct (and descriptive) terms when they are provided.
Helicopters are far more flexible than fixed wing and so require a different set of terms; yes, Take-off Decision Point (TDP) can be seen as similar (in the case of the ‘clear area’ profile which is analogous to runway operations) to V1 but that is the only case - even then TDP is also associated with a height (unlike V1 for fixed wing).
As can be seen from AC 29-2C there is no need “…to identify TDP by height and airspeed, since height alone or other factors may be more appropriate.” That makes the use of V1 under any circumstances questionable.
Similarly, take-off safety speed (Vtoss) should be used and not V2.
To relate any of these to hover taxi is not really appropriate as it is the combination of height and airspeed (and flight testing) which ensures that these ‘points’ are clear of the HV diagram - which always contains the low-level high-speed avoid area.
By the way, you never did identify the helicopter which has these terms.
Jim
Avoid imitations
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JimL,
Yes, I accept your point about V1 (TDP) that but I was responding to a point made regarding hover taxying speeds, which in my mind do relate to operations over a clear area.
I just checked the RFM clear area graph; it does use the terms V2 and TDP. I will correct my earlier post forthwith! Thanks for that.
I suspect major thread drift is about to occur, not that it hasn't already...
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Edit: Since posting this and sending my reply to your PM, I have now done some more research in the Flight Safety International Pilot Training Manual. There is a mix of terminology, depending where one looks. In the section describing Single Engine Failure on Takeoff over a clear area, "CDP" (go/no-go) is defined as "V1 at 5 - 10 feet wheel height".
Yes, I accept your point about V1 (TDP) that but I was responding to a point made regarding hover taxying speeds, which in my mind do relate to operations over a clear area.
I just checked the RFM clear area graph; it does use the terms V2 and TDP. I will correct my earlier post forthwith! Thanks for that.
I suspect major thread drift is about to occur, not that it hasn't already...
------------------------------------------------------------------------
Edit: Since posting this and sending my reply to your PM, I have now done some more research in the Flight Safety International Pilot Training Manual. There is a mix of terminology, depending where one looks. In the section describing Single Engine Failure on Takeoff over a clear area, "CDP" (go/no-go) is defined as "V1 at 5 - 10 feet wheel height".
Last edited by ShyTorque; 4th Mar 2006 at 20:18.
Avoid imitations
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TC, I think that must be the case.
Different kettle of fish from Eurocopter doctrine, maybe because the rotors go round the other way.
I did notice the test pilot went fixed wing not too long ago. Maybe all that talk about V1 and V2 finally got to him
Different kettle of fish from Eurocopter doctrine, maybe because the rotors go round the other way.
I did notice the test pilot went fixed wing not too long ago. Maybe all that talk about V1 and V2 finally got to him
