That was totally amazing. Thanks so much for covering this topic and covering it so very well. All we can do is our best and stay proficient. I agree totally, the pilot in the video did an excellent job putting that heavy bird back down as he did and saving their lives.
WOW! ! ! Your video really drove home the reality of a loss of power on takeoff or under 500 feet. I will absolutely pay more attention to takeoffs and the potential for loss of power and rehearse in my mind what will I do if it happens to me everytime I take off from now on. Thank you for the fantastic video and insight.
Good coverage of the tactical situation that can become fluid, Jonathan. I very much agree with your conclusion that Vy is much safer than Vx. In 17,000 hours crop dusting, patrolling pipeline, and flying most of the small trainers in the mountains and off airport, I never had a takeoff that required pitch up after rolling to Vx or Vy. I find neither appropriate on long runways and both to be poor energy management. Crop dusters, even Ag now in turboprop airplanes, always stay level in low ground effect so long as runway is still available for maximum use of free ground effect energy. Altitude is time and would have made several of my eleven engine failures at low altitude fixable. But for me airspeed was life and I always had zoom reserve airspeed, enough airspeed to maneuver to a survivable landing zone in the very near hemisphere in front of the wing. The only viable energy management in Airmen Certification Standards normal, short, and soft field techniques is the soft field technique which at least uses free ground effect until Vx or Vy as appropriate. The problem with saying Vx or Vy as appropriate so much is that neither is ever appropriate on long runways. Students have problems with Vso calibrations where Vso, an out of ground effect number, is not relevant. This causes them and experienced pilots to takeoff too slow, as did the Howard, and to land too fast. Again, good coverage of the problem that too often is fatal when pilots climb to just high enough to kill themselves in the inadvertent stall/fall.
Happy to help! As an instructor and airline pilot I'm thrilled to see a student pilot doing research. There are lots of wise people with different points of view on just about everything, most with good reason. Good luck with your flight training!
I know a pilot it swallowed a valve on takeoff from a small grass airstrip with trees at the end… He shoved the stick forward and his suss 140 did a wheel landing and hit the brakes as hard as he could to try and prevent going off the end of the field, but luckily he used his common sense and put it into a ground loop at the end of the strap so that he didn't go off the end Instructor showed him this was on episode. Six of I wanted Wings back in 1943.
i wonder if it may be better to fly low over the runway till you gather a decent amount of speed then pull up, i realise this is not always possible but you have so much more energy
@@thematt6705 Unless he was practicing the energy inefficient ACS short field technique, there was absolute no need to pitch to Vx pitch attitude as soon as Vx airspeed was reached. In actual short field takeoff situations, I have always found acceleration level in low ground effect to the obstruction to work. Tail up as soon as it can be elevatored up. Mains off much slower than Vso because the airplane will fly in low ground effect much slower than Vso, and out of ground effect airspeed. Push the stick forward to bracket/remain in low ground effect until the obstruction forces pitch up. Zoom over the obstruction with the outcome never in doubt. At Vx, the outcome is always in doubt.
Your question is an excellent one! The answer is "It depends", and it gets pretty technical. Strictly from a performance perspective the general performance of jets is a little different from props, and there's s a discussion to be had there. But there are other considerations to factor as well. The combination of technical and human factors here could make for an awesome video! This is also something I could demonstrate with either of the planes. I can write at length about this and still not cover all of the factors.
@@jonathanzarinnia884 Technically airspeed is altitude and altitude is airspeed and therefore they are of equal value. But ground effect is so powerful for acceleration, should it not be in a different bucket and be valued for the zoom reserve airspeed it provides, along with fuel energy. In the small trainers of 65-150 hp I flew in the Rockies, ground effect energy was surely 50% of my total energy on many high DA takeoffs. And we haven't even considered down drainage egress, but that is the potential energy of altitude. Like the ground effect, down drainage egress from the airport is free energy. Just don't try to go up fast enough to kill yourself. So perhaps together 75% of the energy available in an old and tired DC-65 Taylorcraft at Alamosa, Colorado when it was too hot for Continental Airlines to land/takeoff was ground effect and down drainage egress. The problem with more powerful airplanes is that we don't need this extra free energy...until we do. The problem with the Howard takeoff is that every bit of the hundred feet or so of altitude was bought with precious airspeed kinetic energy. None of that altitude was free and it was insufficient for recovery from inadvertent mush or stall. Wolfgang would ask us, "What does the airplane want to do." Does it want to maintain altitude or maintain trimmed airspeed? He got the nose down quickly but stall recovery is best done with knowledge that we are going to do it and with sufficient altitude to recover. If there had never been a PTS or ACS or V speed or Vx or Vy as appropriate, how many airplanes would still be here and how many pilots? We had more incidents and accidents just using the principles in "Stick and Rudder." We had no more fatalities, however. It seems we are quite well avoiding many of the old problems except inadvertent stalls around the airport and loss of control on landing with enough speed to kill airplanes and pilots. And then there are the go around LOC accidents. I got a D in college algebra and only took astronomy for non-science majors. I need some help with the math on what I know to be true from 17,000 hours at 200' or below crop dusting and patrolling pipelines.
0:00 Minor point...but it was a simulated SOFT, not SHORT, field takeoff. SOFT is to minimize weight on wheels, SHORT is to minimize takeoff roll. Example of short field takeoff: ua-cam.com/video/ukb58k-dFZI/v-deo.htmlsi=gnfPEBYIkmPuMk9b
I think Vy is at the mid-point between the front-side and back-sides of the power curve, isn't it? Since it's essentially your "full power min sink" speed. (Edit: "min sink" not "best glide")
This is awesome question. Best rate of climb is where the plane has the most surplus power. In props and jets that's going to be faster than Vld. Best angle is where the plane has the most surplus thrust. In props that's slower. In jets best angle of climb is nearly the same as best glide. Minimum sink is where the least power is required, slower than best glide. Best angle of glide is where the plane has the most lift compared to drag. At best glide speed. Rates are dependent on surplus or deficits in power. Angles are dependent on surplus or deficits in thrust. Power looks at forces over distance and time, so think force and speed. Thrust just looks at straight pounds of thrust and pounds of drag.
@@jonathanzarinnia884 Thanks! Great discussion. This is the level of detail that's great to find in aviation YT. I think I understand what's going on. There are two slightly different perspectives how the power curve applies to real engines and props, which are dependent on airspeed. 1. The traditional approach (which I believe is exemplified by the Navy book you referenced) is to build the power curve based on lift and drag performance. This involves determining the sum of the effects of induced and parasitic drag components, which can be summarized in a "power required" curve, which is the amount of power that the aircraft would have to provide at various airspeeds in order to remain level. This curve will necessarily be convex and have a minimum point, which corresponds to the best ratio of lift to drag, and we call the associated airspeed V_ld(max). However, this is only a true minimum point in the case that the same power can be provided at all airspeeds. This is true at idle, so this works for determining V_minsink, since the engine and prop are not contributing anyway. But at any non-zero thrust level, the fact that power is a function of airspeed means that the min point as per V_ld(max) won't correspond to an optimal airspeed for climb. 2. The other approach, which I'm calling the Denker approach (since it's what's used in See How It Flies), is to flip the "power required" curve into a "power available" curve, which looks similar but it's upside-down. But more importantly, Denker factors the performance of the engine and the prop into the power available curve, so at non-idle power, the curve represents the surplus or deficit at power across a range of airspeeds in that configuration which includes the position of the throttle (and prop pitch, etc.), and not solely aerodynamic effects. This curve does factor in the engine, and so it's maximum point would differ from V_ld(max). This is what Denker is calling Vy. The question is what are the characteristics of this portion of the power curve, between Vy at a given thrust, and V_ld(max)? (I recognize that this region is likely to be only a couple of knots in the kinds of airplanes that we fly, but it's still an interesting discussion point.) If I'm at V_y, and i begin to pitch up, I'm not able to hold altitude as well, so it feels to me like the back-side of the power curve. Whether that effect is due to loss of aerodynamic efficiency or due to the ineffectiveness of the powerplant, I'm not sure it matters as a pilot. Does anything interesting happen when you cross V_ld(max) one way or the other?
WW II training films and books were the basis of your syllabus when you were a 15 yr old learning to fly you were taught that VX was a minimum speed. VY was a target speed…… there is a difference between min max or target speeds What does that mean? It means that when we study the great instructors such as Commander John Hoyt, United States, Navy, who was at Gross in World War II, who wrote the very training manual you read the cadet maneuvers manual that you read and later 1944's safety after solo there is much to learn The training films USNAVY quit stallin or spin in Still relevant today Cdr. Hoyt stressed that Vx 1.3 vs1g/config. Was a minimum and if you could add a few mph for mom and the kids do so Speed vs controllability Airfield analysis T1-T2 and decision points Expounded upon by Jimmy Stewarts film cowby57 Referenced and explained by Hoyt in as the pro flies Even now we have v2 and V2 minimum in transport catagory airplanes in the performance guidance given to pilots Excellent video Sir Lookin good
Spot on the subject! I’ve been a CFI for 39 years.this is an excellent video.
Great to hear!
That was totally amazing. Thanks so much for covering this topic and covering it so very well. All we can do is our best and stay proficient. I agree totally, the pilot in the video did an excellent job putting that heavy bird back down as he did and saving their lives.
Thanks! Glad you enjoyed it!
Thank you for making these excellent videos!
WOW! ! ! Your video really drove home the reality of a loss of power on takeoff or under 500 feet. I will absolutely pay more attention to takeoffs and the potential for loss of power and rehearse in my mind what will I do if it happens to me everytime I take off from now on. Thank you for the fantastic video and insight.
Good coverage of the tactical situation that can become fluid, Jonathan. I very much agree with your conclusion that Vy is much safer than Vx. In 17,000 hours crop dusting, patrolling pipeline, and flying most of the small trainers in the mountains and off airport, I never had a takeoff that required pitch up after rolling to Vx or Vy. I find neither appropriate on long runways and both to be poor energy management. Crop dusters, even Ag now in turboprop airplanes, always stay level in low ground effect so long as runway is still available for maximum use of free ground effect energy. Altitude is time and would have made several of my eleven engine failures at low altitude fixable. But for me airspeed was life and I always had zoom reserve airspeed, enough airspeed to maneuver to a survivable landing zone in the very near hemisphere in front of the wing. The only viable energy management in Airmen Certification Standards normal, short, and soft field techniques is the soft field technique which at least uses free ground effect until Vx or Vy as appropriate. The problem with saying Vx or Vy as appropriate so much is that neither is ever appropriate on long runways. Students have problems with Vso calibrations where Vso, an out of ground effect number, is not relevant. This causes them and experienced pilots to takeoff too slow, as did the Howard, and to land too fast.
Again, good coverage of the problem that too often is fatal when pilots climb to just high enough to kill themselves in the inadvertent stall/fall.
Thanks! I'm working on my next video about roll upsets.
The pilot did a great job all things considered
Great stuff!
as a 15 year old who only has 16 hours and still learning, thank you! gotta love free flying advice
Happy to help! As an instructor and airline pilot I'm thrilled to see a student pilot doing research. There are lots of wise people with different points of view on just about everything, most with good reason. Good luck with your flight training!
I know a pilot it swallowed a valve on takeoff from a small grass airstrip with trees at the end… He shoved the stick forward and his suss 140 did a wheel landing and hit the brakes as hard as he could to try and prevent going off the end of the field, but luckily he used his common sense and put it into a ground loop at the end of the strap so that he didn't go off the end Instructor showed him this was on episode. Six of I wanted Wings back in 1943.
i wonder if it may be better to fly low over the runway till you gather a decent amount of speed then pull up, i realise this is not always possible but you have so much more energy
You have innate understanding of total energy management. It is always better on long runways.
Of course you can, but the pilot in this scenario was practicing a short-field takeoff, so it would completely defeat the purpose
@@thematt6705 Unless he was practicing the energy inefficient ACS short field technique, there was absolute no need to pitch to Vx pitch attitude as soon as Vx airspeed was reached. In actual short field takeoff situations, I have always found acceleration level in low ground effect to the obstruction to work. Tail up as soon as it can be elevatored up. Mains off much slower than Vso because the airplane will fly in low ground effect much slower than Vso, and out of ground effect airspeed. Push the stick forward to bracket/remain in low ground effect until the obstruction forces pitch up. Zoom over the obstruction with the outcome never in doubt. At Vx, the outcome is always in doubt.
Your question is an excellent one! The answer is "It depends", and it gets pretty technical. Strictly from a performance perspective the general performance of jets is a little different from props, and there's s a discussion to be had there. But there are other considerations to factor as well. The combination of technical and human factors here could make for an awesome video! This is also something I could demonstrate with either of the planes.
I can write at length about this and still not cover all of the factors.
@@jonathanzarinnia884 Technically airspeed is altitude and altitude is airspeed and therefore they are of equal value. But ground effect is so powerful for acceleration, should it not be in a different bucket and be valued for the zoom reserve airspeed it provides, along with fuel energy. In the small trainers of 65-150 hp I flew in the Rockies, ground effect energy was surely 50% of my total energy on many high DA takeoffs. And we haven't even considered down drainage egress, but that is the potential energy of altitude. Like the ground effect, down drainage egress from the airport is free energy. Just don't try to go up fast enough to kill yourself. So perhaps together 75% of the energy available in an old and tired DC-65 Taylorcraft at Alamosa, Colorado when it was too hot for Continental Airlines to land/takeoff was ground effect and down drainage egress. The problem with more powerful airplanes is that we don't need this extra free energy...until we do.
The problem with the Howard takeoff is that every bit of the hundred feet or so of altitude was bought with precious airspeed kinetic energy. None of that altitude was free and it was insufficient for recovery from inadvertent mush or stall. Wolfgang would ask us, "What does the airplane want to do." Does it want to maintain altitude or maintain trimmed airspeed? He got the nose down quickly but stall recovery is best done with knowledge that we are going to do it and with sufficient altitude to recover.
If there had never been a PTS or ACS or V speed or Vx or Vy as appropriate, how many airplanes would still be here and how many pilots? We had more incidents and accidents just using the principles in "Stick and Rudder." We had no more fatalities, however. It seems we are quite well avoiding many of the old problems except inadvertent stalls around the airport and loss of control on landing with enough speed to kill airplanes and pilots. And then there are the go around LOC accidents.
I got a D in college algebra and only took astronomy for non-science majors. I need some help with the math on what I know to be true from 17,000 hours at 200' or below crop dusting and patrolling pipelines.
0:00 Minor point...but it was a simulated SOFT, not SHORT, field takeoff.
SOFT is to minimize weight on wheels, SHORT is to minimize takeoff roll.
Example of short field takeoff:
ua-cam.com/video/ukb58k-dFZI/v-deo.htmlsi=gnfPEBYIkmPuMk9b
I think Vy is at the mid-point between the front-side and back-sides of the power curve, isn't it? Since it's essentially your "full power min sink" speed. (Edit: "min sink" not "best glide")
This is awesome question. Best rate of climb is where the plane has the most surplus power. In props and jets that's going to be faster than Vld. Best angle is where the plane has the most surplus thrust. In props that's slower. In jets best angle of climb is nearly the same as best glide.
Minimum sink is where the least power is required, slower than best glide.
Best angle of glide is where the plane has the most lift compared to drag. At best glide speed.
Rates are dependent on surplus or deficits in power. Angles are dependent on surplus or deficits in thrust. Power looks at forces over distance and time, so think force and speed. Thrust just looks at straight pounds of thrust and pounds of drag.
@@jonathanzarinnia884 Thanks! Great discussion. This is the level of detail that's great to find in aviation YT.
I think I understand what's going on. There are two slightly different perspectives how the power curve applies to real engines and props, which are dependent on airspeed.
1. The traditional approach (which I believe is exemplified by the Navy book you referenced) is to build the power curve based on lift and drag performance. This involves determining the sum of the effects of induced and parasitic drag components, which can be summarized in a "power required" curve, which is the amount of power that the aircraft would have to provide at various airspeeds in order to remain level. This curve will necessarily be convex and have a minimum point, which corresponds to the best ratio of lift to drag, and we call the associated airspeed V_ld(max).
However, this is only a true minimum point in the case that the same power can be provided at all airspeeds. This is true at idle, so this works for determining V_minsink, since the engine and prop are not contributing anyway. But at any non-zero thrust level, the fact that power is a function of airspeed means that the min point as per V_ld(max) won't correspond to an optimal airspeed for climb.
2. The other approach, which I'm calling the Denker approach (since it's what's used in See How It Flies), is to flip the "power required" curve into a "power available" curve, which looks similar but it's upside-down. But more importantly, Denker factors the performance of the engine and the prop into the power available curve, so at non-idle power, the curve represents the surplus or deficit at power across a range of airspeeds in that configuration which includes the position of the throttle (and prop pitch, etc.), and not solely aerodynamic effects. This curve does factor in the engine, and so it's maximum point would differ from V_ld(max). This is what Denker is calling Vy.
The question is what are the characteristics of this portion of the power curve, between Vy at a given thrust, and V_ld(max)? (I recognize that this region is likely to be only a couple of knots in the kinds of airplanes that we fly, but it's still an interesting discussion point.) If I'm at V_y, and i begin to pitch up, I'm not able to hold altitude as well, so it feels to me like the back-side of the power curve. Whether that effect is due to loss of aerodynamic efficiency or due to the ineffectiveness of the powerplant, I'm not sure it matters as a pilot. Does anything interesting happen when you cross V_ld(max) one way or the other?
WW II training films and books were the basis of your syllabus when you were a 15 yr old learning to fly
you were taught that VX was a minimum speed. VY was a target speed…… there is a difference between min max or target speeds
What does that mean?
It means that when we study the great instructors such as Commander John Hoyt, United States, Navy, who was at Gross in World War II, who wrote the very training manual you read the cadet maneuvers manual that you read and later 1944's safety after solo there is much to learn
The training films USNAVY quit stallin or spin in
Still relevant today
Cdr. Hoyt stressed that Vx 1.3 vs1g/config. Was a minimum and if you could add a few mph for mom and the kids do so
Speed vs controllability
Airfield analysis T1-T2 and decision points
Expounded upon by Jimmy Stewarts film cowby57
Referenced and explained by Hoyt in as the pro flies
Even now we have v2 and V2 minimum in transport catagory airplanes in the performance guidance given to pilots
Excellent video Sir
Lookin good