In the thread, unnecessarily steep climb, I talked about not giving up airspeed to climb quickly when too low to recover from stall. In maneuvering flight, staying low throughout, there are few valid reasons to give up airspeed. Airspeed is potential altitude and airspeed is maneuverability. Slowing down occurs quite naturally in the zoom up wings level portion of the energy management turn, but that portion is followed by release of back pressure and resultant pitch down in the rudder and bank to turn. A bit of energy management has put the law of the roller coaster and dynamic neutral stability to work for us. We have achieved maximum radius reduction, if needed, while not giving up airspeed continuously as with the level turn. MTV's slow cruise in PVFR and Butch Washtock's slow and level rudder pulling aileron turns in BC's glacier carved, straight sided valleys are exceptions to the low altitude airspeed emphasis. Let me know if I have missed something, but in most situations airspeed, our only sure energy source, is critical to safe maneuvering flight? We need that kinetic energy to zoom up to start turns allowing potential energy (gravity) to insure 1g turns at whatever bank is necessary to miss stuff... perpetual balance.

Without zoom reserve airspeed, unnecessarily steep results in unnecessarily slow. There is a lifetime of difference between zoom climb to begin the energy management turn and engine climb at Vx or Vy to gain altitude quickly...supposedly. The former is simply taking advantage of the law of the roller coaster and maximum banked 1g turns. The latter is a prescription for end of life without insurance. Neither Vx nor Vy is appropriate for other than short field takeoff over obstruction after acceleration in low ground effect. Obstruction crossing should be as low as practicable and followed by pushing forward on the stick to level the airplane over the obstruction. This, or any low altitude maneuver, should be taught with a return to maneuvering airspeed as soon as practicable. Without >1000' for potential energy stall recovery, airspeed is our only reliable altitude or maneuverability. While at Vx or Vy below 1000,' the outcome of any maneuver is continuously in doubt. Requiring young and inexperienced instructors and students to spend any more time than absolutely necessary at Vx or Vy below 1000' is unnecessarily unsafe. Such is where distractions, abnormals, natural conditions, and less than perfect control manipulation can be fatal. And after PPL, continuous use of this dangerously slow takeoff procedure, rather than just over the obstruction after acceleration in low ground effect, is the bullet with that poor student's name on it. The instructor: acceptable loss. For low level work, there is no need to go to altitude. For high altitude work, reasonable DMMS pitch attitude gets one up plenty fast enough without seeking that bullet.

Finally, there is a phrase I dislike: "Low and Slow." Hopefully, the pilot using that phrase is talking about 60 mph cruise in his 65 hp airplane. If so, no problem. If, however, he is talking about reducing airspeed during maneuvering flight (other than MTV's or Butch's conditions,) this sounds very dangerous. There is no V speed for zoom reserve. It is as much as we can get. It gets us up without engine power if we lose the engine. It allows aggressive maneuvering because there is zoom reserve airspeed to give up for altitude and slower airspeed in the energy management turn. The energy management turn, from shallow to very steep, is the only 1g safety turn at whatever bank and therefore the only safe maneuvering flight turn. DMMS works in the pattern where we can limit bank, but we shouldn't have to limit bank. Bank should automatically be whatever bank is needed with no thought about limit. This is entirely possible with some practice and can become default at low altitude including pattern altitude. In river runs or pipeline patrols, giving up airspeed to make the tighter turns is dangerously poor energy management. If the river or right of way tightens too much and the airspeed gets too slow to increase bank without stall, we could go wings level and bail...if terrain and obstructions permitted. Pitching up to gain both altitude and reduced airspeed for decreased radius of turn is the only way to prevent getting between a rock and a hard place. If that happens, fly all the way to the landing in the river or on the right of way. Or rudder turn in low ground effect. Not as comfortable, but it will get you there. A bit more airspeed would be nice for that as well.

I am not a super pilot. All these safe maneuvering flight techniques are hum drum to the crop duster. He doesn't reduce power to reduce the radius of turn. He zooms up, banks at whatever bank necessary while slow but pitching down naturally, and returns to cruise going into the next crop row. He doesn't fly around making level turns at reduced power reconing the field he is going to spray. He makes various energy management turns to target (what he wants to see ahead in a slight dive.) He doesn't look out the side. What is out the side is a done deal. He is staying ahead of the airplane. Because of the apparent rate of closure, he seem to be going at a comfortable brisk walk and has time to observe detail. Many, many very experienced and very proficient pilots have made level turns around targets in animal counts and such for many years and are still alive. Given the same hours of exposure to the low altitude work, even more crop dusters are still alive. Hunting animals with airplane or helicopter is a deadly game for all. A gun pilot would just roll into an energy management turn to target, roll out and zoom back up into an energy management return to target, etc. etc. rather than circle at a constant altitude until levelling the wing is necessary to prevent stall.

Thanks Jim !

The aerial reconnaissance advantage of the helicopter is that it can be safely flown at slow airspeed. My loach in Vietnam worked NOE in right circles while I circled him at 1200" and 40 knots. He hovered in a low threat environment and increased airspeed in more dangerous areas. The increased airspeed allowed an energy management turn to put jungle between him and Charlie.

My very slow airspeed at considerable altitude allowed immediate turn to target and extra time on target, but the dive increased airspeed to as much as 190 knots for the zoom climb tip path plane level before a very steep 1g turn to return to target.

Both the potential energy of altitude and the kinetic energy of airspeed are powerful and can be rapidly utilized. Engine thrust is less powerful and cannot be as quickly utalized. When low we are without much potential energy of altitude and therefore giving up airspeed is really scary.

I can see the attraction of slow airspeed low level on the river to reduce the radius of turn, but the danger is the lack of go to energy. We need zoom reserve in the form of airspeed (ability to climb w/o engine power) or in the form of altitude (gravity.) The more common high altitude orientation has most pilots thinking in terms of altitude as the go to energy source. They consider, I am sure, that they have little gravity energy low level. Do they consider that they have also given up ground effect energy by flying high enough to turn without catching the low wing in the river? Doesn't it get a little scary giving up gravity, giving up ground effect, and giving up airspeed without argument?

So we can put a big engine up front. That will provide some reserve energy when flying around at less than cruise power. But what about the close trees and fairly close cliffs and various terrain? And what if it quits? Consider that in 13 engine failures ol contact has never landed in the field he was working in. How did he get to that adjoining field without engine power? Airspeed, airspeed, airspeed. The law of the roller coaster. Airspeed is the go to energy in low latitude work. Airspeed delivers zoom reserve every time. It is only a six second deal, but a lot can be done with three seconds of zoom up and then a little gravity down. More importantly, airspeed provides reliable energy for the much safer energy management turn. When both vertical and horizontal space available is limited, the ability to turn at any bank angle and remain at 1g is powerfully safe. At any bank angle I desire, I can make all but hairpin turns on any river or pipeline. Also importantly, I can make shallow turns more comfortably and they are less likely to become dangerously more interesting.

With cruise (zoom reserve) airspeed, I can stay in low ground effect. I will zoom up a bit, wings level, before turning while allowing the nose to go down onto the target (river in new direction.) I can rudder turn small turns if I choose. Now I am utilizing ground effect, zoom reserve airspeed, gravity after any zoom up, and engine power. 17,000 hours down there have taught me I want all the reserve energy available. I might even jump on some ridge lift on the ridge downwind of the river or pipeline.