Steep climbouts
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Steep climbouts
Again, I see videos posted (elsewhere) which show over eager pilots demonstrating the "STOL" capabilities of their aircraft. They seem to miss the point that once airborne, most of the "T" part of STOL has been accomplished.
Hanging off the prop at 30 to a few hundred feet, with hardly any airspeed, is a recipe for a very harmful crash if the engine quits. If there is an operational need, so be it, but most of us are not Hanna Reitsch flying Hitler off a Berlin street, out of gunfire range.
New and showoff pilots: Understand that there is a slow and low "envelope", from which a glide cannot be safely entered, if it quits, you will simply hit the ground in a clump of hurt, with no good excuse for why you and you plane are bent. Build some speed after getting airborne.
This week I spent two days mentor flying three company pilots, whose boss installed a STOL kit on their patrol aircraft, for safety. The boss hired me to do this additional training, after our discussion about the modified aircraft being a greater temptation for unsafe steep departure type foolishness. Once I demonstrated the real scary situation one could create for oneself (at altitude, of course), the pilots seemed to really appreciate the wisdom.
I'm old (my kids tell me). I can't go back, and be young and foolish, so I'll make the most of being old, and stop doing stupid things in planes - like silly steep climbouts, for no reason other showing off to people on the ground.
Hanging off the prop at 30 to a few hundred feet, with hardly any airspeed, is a recipe for a very harmful crash if the engine quits. If there is an operational need, so be it, but most of us are not Hanna Reitsch flying Hitler off a Berlin street, out of gunfire range.
New and showoff pilots: Understand that there is a slow and low "envelope", from which a glide cannot be safely entered, if it quits, you will simply hit the ground in a clump of hurt, with no good excuse for why you and you plane are bent. Build some speed after getting airborne.
This week I spent two days mentor flying three company pilots, whose boss installed a STOL kit on their patrol aircraft, for safety. The boss hired me to do this additional training, after our discussion about the modified aircraft being a greater temptation for unsafe steep departure type foolishness. Once I demonstrated the real scary situation one could create for oneself (at altitude, of course), the pilots seemed to really appreciate the wisdom.
I'm old (my kids tell me). I can't go back, and be young and foolish, so I'll make the most of being old, and stop doing stupid things in planes - like silly steep climbouts, for no reason other showing off to people on the ground.
I did the following exercise with all my students
At altitude in the practice area, set up a full power climb at Vx. I then smoothly but fairly rapidly pulled the power back to idle to simulate an engine failure. The challenge was to get the airplane to a condition of best glide speed and normal rate of descent, usually about 600 ft min. Most students lost several hundred feet making the transition.
The take aways:
1) An immediate and significant pitch down is required or the airplane will very quickly enter a mushing stall with a huge rate of descent.
2) an initial pitch attitude significantly more nose down than what is the correct attitude to hold the normal glide speed is required in order for the aircraft to accelerate to a safe glide speed
3) The transition will take altitude so there is a no go zone where a power failure, while at Vx will result in a touchdown with a high rate of descent
The bottom line: Hold Vx only as long as you need to clear the obstacle and as quickly as possible accelerate to a higher speed and be prepared to apply an immediate large nose done pitch if the engine fails in the Vx climb.
At altitude in the practice area, set up a full power climb at Vx. I then smoothly but fairly rapidly pulled the power back to idle to simulate an engine failure. The challenge was to get the airplane to a condition of best glide speed and normal rate of descent, usually about 600 ft min. Most students lost several hundred feet making the transition.
The take aways:
1) An immediate and significant pitch down is required or the airplane will very quickly enter a mushing stall with a huge rate of descent.
2) an initial pitch attitude significantly more nose down than what is the correct attitude to hold the normal glide speed is required in order for the aircraft to accelerate to a safe glide speed
3) The transition will take altitude so there is a no go zone where a power failure, while at Vx will result in a touchdown with a high rate of descent
The bottom line: Hold Vx only as long as you need to clear the obstacle and as quickly as possible accelerate to a higher speed and be prepared to apply an immediate large nose done pitch if the engine fails in the Vx climb.
I see this sort of thing a lot in low inertia and usually high drag LSA/microlite type aircraft.
The engine only has to cough and they're in trouble. No energy to be able to lower the nose to start with, let alone worry about the altitude needed to regain glide speed.
Darwin's Law at work?
The engine only has to cough and they're in trouble. No energy to be able to lower the nose to start with, let alone worry about the altitude needed to regain glide speed.
Darwin's Law at work?
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If you ever need to convince someone that steep climbouts is a bad idea, here's what happens in the glider world.
Traditionally glider winch cables were made from steel. They had a finite life, so cable breaks were very, very common. More modern winches now use dyneema or some other type of high-strength carbon fibre/composite so breaks are less likely but still not unheard of.
During the winch launch, the whole launch sequence is carefully designed so that if the cable breaks at any point, you can always safely recover. This means we work in stages.
Once the winch starts pulling the aircraft rolls along the ground initially. As soon as the wheels leave the ground, you need to push the nose down, otherwise the couple from the winch may pull you vertical (has to do with the hook location on the fuselage). You keep the nose down (at most some 20-30 degree nose up) until the aircraft reaches a height of about 50 meters. At that height you can slowly raise the nose, perhaps to as much as 60 degrees nose up.
A 300 HP winch pulling at a glider with only 20 degrees of pitch means the aircraft is constantly accelerating. To possibly as much as 2xVs, or even into the yellow band (>Va). That's perfectly OK: You need that speed to set up the glide attitude if the cable breaks.
Once you are at a safe height and start pitching up more, the speed automatically reduces. To maybe 1.25 or 1.5 times Vs. That's fine as well as we now have the height to setup the glide if the cable breaks.
(Most competent glider pilots actually transition smoothly from one stage to the other, initially trading height gain for speed, and later on trading speed for height gain.)
Steep launches, where the aircraft gets off the ground and immediately gets into a 45-degree or more pitch up, are severely frowned upon and will cause a reprimand from the lead instructor. Or even grounding. People have died from that type of launches.
Traditionally glider winch cables were made from steel. They had a finite life, so cable breaks were very, very common. More modern winches now use dyneema or some other type of high-strength carbon fibre/composite so breaks are less likely but still not unheard of.
During the winch launch, the whole launch sequence is carefully designed so that if the cable breaks at any point, you can always safely recover. This means we work in stages.
Once the winch starts pulling the aircraft rolls along the ground initially. As soon as the wheels leave the ground, you need to push the nose down, otherwise the couple from the winch may pull you vertical (has to do with the hook location on the fuselage). You keep the nose down (at most some 20-30 degree nose up) until the aircraft reaches a height of about 50 meters. At that height you can slowly raise the nose, perhaps to as much as 60 degrees nose up.
A 300 HP winch pulling at a glider with only 20 degrees of pitch means the aircraft is constantly accelerating. To possibly as much as 2xVs, or even into the yellow band (>Va). That's perfectly OK: You need that speed to set up the glide attitude if the cable breaks.
Once you are at a safe height and start pitching up more, the speed automatically reduces. To maybe 1.25 or 1.5 times Vs. That's fine as well as we now have the height to setup the glide if the cable breaks.
(Most competent glider pilots actually transition smoothly from one stage to the other, initially trading height gain for speed, and later on trading speed for height gain.)
Steep launches, where the aircraft gets off the ground and immediately gets into a 45-degree or more pitch up, are severely frowned upon and will cause a reprimand from the lead instructor. Or even grounding. People have died from that type of launches.
The BGA booklet (URL below) gives some insights into the risks of steep climbs near the ground if there is a power failure or cable break when winch launching. There is a part of the envelope when in a steep climb at relatively slow speed near trhe ground it is not recoverable.
https://members.gliding.co.uk/librar...ching-booklet/
https://members.gliding.co.uk/librar...ching-booklet/
If you're risk averse and allergic to adrenaline, Don't do it. On the other hand....
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FLYINGMAC. If that was 2005,Thunder City, I was there when that take-off was filmed. It was the 'climb to height' record attempt IIRC. Must have scared hell out of the people driving past on the main road!!!!.
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If you're risk averse and allergic to adrenaline, Don't do it. On the other hand....
https://www.youtube.com/watch?v=_CDLbokf9sg
https://www.youtube.com/watch?v=_CDLbokf9sg
I saw the result of one where the thing was dragged off the ground too early, pulled to the vertical, it stalled and spun, not a pretty sight.
