Zoom Climb

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Ivan1GFP said:
Here is a silly question for you:
If an aircraft goes vertical when translating KE to Altitude, is it considered a Zoom Climb?
If so, Where is the lift when an aircraft is going vertical?
Click to expand...
The lift comes from the thrust of the engine and propeller when travelling vertically, in WW2 aircraft this is insufficient to continue so the plane slows rapidly and then stalls. However aircraft with bigger propellers and lower weight were introduced during WW2, they are called helicopters or sometimes rotary wing aircraft. Later jets could climb vertically, the lightning could for example, because it had massive thrust compared to its weight, however the maximum rate of climb was at an angle, at higher speed with the wings providing lift. An aircraft travelling at high speed in level flight then going vertical uses the wings to do so, this means an increase in AoA and drag, even with an engine providing 2,000BHP as thrust it slows rapidly and stops.
 
Ivan1GFP said:
Here is a silly question for you:
If an aircraft goes vertical when translating KE to Altitude, is it considered a Zoom Climb?
If so, Where is the lift when an aircraft is going vertical?
Click to expand...
Not too sure.

I was playing with you, not being obnoxious ... at least, I wasn't trying to be obnoxious.

If I can answer seriously, that's ballistic flight, but straight up? Don't know if that would be a zoom climb or not. I realize your question is basically a yes or no question, but ...

To me, a zoom climb is what happens when you are flying more or less straight and level, leave the power where it is or push it higher, and pull up into a climb that exceeds what your climb rate is once your speed decays down to best-climb speed. All the excess climb rate is zoom climb to whatever altitude you reach when the speed falls to best-climb speed. I never thought much of going vertical, but you go THROUGH vertical when you fly a loop in which, hopefully, you get to horizontal inverted at the top before running out of speed. If you don't, I suppose you just fall though the attempt. They showed a good one of those in ,"The Great Waldo Pepper."

So, the short answer is no, but heck, it might be. If we were in a Piper Cherokee 180, we might or might not get the nose vertical before we ran out of speed altogether. Might be fun to try it, might not be. Depends on whether or not you still have wings when you finish.
 
All of this Physics makes my brain hurt, but still does not explain why the smallest screw or nut dropped from 3 feet, carpet or hard surface, will be found 9 feet from where it is dropped. It seems very small mass plus gravity changes potential energy to kinetic energy (or vice versa) cannot be explained by lift or airflow when there is none.
 
That is explained by Newtons eighth law, MAGIC.
 
There are definitions that describe Zoom as a sudden movement, and even Zoom-climb as a climb that trades speed for height. Generally, I think those are fair, a sudden climb that trades speed for height. Of course, lift may still be developed, but in a ballistic path that need not happen and the force of gravity will prevail, or partially prevail depending on the AoA, determined by control. Vertical ascent of a conventional fixed-wing aircraft may not generate lift and so maintains a zero-lift AoA or the flightpath will depart from the vertical.
Some definitions do not account for thrust greater than weight and drag, which can see an accelerating vertical climb by some aircraft. However, most aircraft will lose speed in a climb rate that exceeds their power to maintain speed in the climb rate at that moment, and the Zoom part ends with a change to an attitude that the aircraft can maintain with the power available, or it stalls-out and departs if it has exceeded its ability to maintain the altitude achieved in the Zoom.

Eng
 
I thought that was an immutable law of nature .... "Whatever can go wrong not only WILL go wrong, but will do so at the worst possible time in a manner so as to cause the most damage.

Or, "the probability of a piece of toast falling butter-side down is directly proportional to the cost of the carpet."

No doubt, there are others of equal or greater wisdom, such as, "leakproof seal aren't!" and such.
 
It is also proportional to the hunger of the person who buttered the toast and inversely proportional to how many slices of bread remain.
 

Next obvious question would be: At what angle of climb do you NOT consider it a Zoom Climb? 30 Degrees above horizontal? 80 Degrees?

Falling out of a loop is something I experienced almost 30 years ago.
What we (My role on this flight as a friend of mine so eloquently described, was basically "Ballast") were trying to do was perform 4 consecutive loops but with a 90 degree roll on the downward leg of each loop.
From what I recall, we finished two loops and were on the way up on third when we ran out of airspeed and entered a spin.
Nothing really happens very fast in a Cessna, so it was just an interesting experience with plenty of time to recover from the spin.
If the wings came off, I had already been given instructions on how to jettison the door and exit the aircraft and take a parachute ride down. Those instructions were quick enough it seemed they were meant to check off a box.
 
I would not say any angle.

It comes down to when the aircraft arrives at it's best rate of climb airspeed and is at such a climb angle so as to be able to sustain that climb speed at rate.

So, if he arrives at best climb angle while going straight up, he'll just continue to lose airspeed until he stops and starts to fall. But, if he pushes over gradually until he reaches best climb airspeed and is able to hold it, then he is at sustained climb rate.

Almost any pilot who flies an aircraft gets to know it a bit as he or she flies it. Personally, when I was getting my first few flying lessons in a Cessna 150, there came a time when I could pull it up steeply and push over to hold climb airspeed, and I had very few flying hours at the time. It isn't especially difficult.
 
Leaving jets, and especially jets with high amounts of thrust of this, we need to figure out what "zoom" climb is. You can "zoom" climb for level flight. You won't zoom quite as well as zooming after pulling out of dive (booming) at higher than level flight but...........................

Now a Spitfire V with a Merlin 50 engine (cropped impeller) could do about 342mph at 4000ft in level flight. Best climb speed was 170mph. Now how does our pilot use his kinetic.
energy?
At low altitude with the cropped supercharger he actually has a rather steep climbing angle. At 170mph and 4700fpm climb hi can climb 1 ft for every 3.2 feet he goes forward (17.35 degrees) With that extra 170mph in hand he can climb gradually and keep his speed from falling as quickly or he can try to climb at 45 degree angle and loose speed quickly (gaining altitude quickly) and the reduce the climb angle as the air speed falls of.

If our pilot had been diving at 420mph he would have more energy to play with. But that energy is going to go away quickly in a steep climb.

You can almost always climb steeper than best climb angle, you just can't do it for very long.
 
Well, you could use best angle or best rate. Best angle is steeper, but best rate will get you to a higher altitude faster than best angle.

An exact definition of zoom climb may not be necessary since almost everyone in here recognizes what zoom climb is. I've seen it at every airshow where they have an aerobatic demo by a piston fighter. Since I volunteer at a museum that flies WWII fighters, I've seen it frequently. Always impressive to see a Sea Fury, Mustang, Bearcat, Thunderbolt, Lightning, Spitfire, or whatever go vertical for a long line at least 3,000 feet before pulling over the top.
 
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The link is another of those frustrating videos with a continuous loop commercial up front. No meat in that sandwich!
 
I understand, Barrett, but all the demo teams zoom climb into aerobatics and use the extra altitude gained to make nice big, round loops and cuban eights. If they flew in at cruise and pulled vertical, they wouldn't go that far up. The only thing lacking is slowing to best-rate and continuing the climb ... which sort of defeats the purpose of an airshow demo. A real zoom climb isn't all that entertaining to watch, even if you know what you are seeing.
 
Zoom climb is not an angle. It is a sustained airspeed anywhere between best angle and best rate of climb. If you are faster than best rate and are climbing with a greater rate of climb than best sustained rate, you are at some point in a zoom climb. If you are at a sustained speed between those two points, you are at or between best rate and best angle.

You can be at best rate airspeed and accelerating if you are in a dive and you can be at best rate airspeed and decelerating if you are climbing. If in a dive, you are obviously not in a zoom climb. but, if your climb rate is better than normal best rate of climb and you are decelerating through best rate airspeed, you are in a zoom climb near the end of it because you won't have far to go before you stall or decrease your angle of climb so as to maintain airspeed.

This assumes, of course, that you are not in a jet fighter with a thrust-to-weight ratio better than 1. In that case, all bets are off since it doesn't follow normal climb procedures at high thrust values.
 
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GregP said:
This assumes, of course, that you are not in a jet fighter with a thrust-to-weight ratio better than 1. In that case, all bets are off since it doesn't follow normal climb procedures at high thrust values.
Click to expand...
I read somewhere that although a Lightning could climb vertically, it climbed fastest at an angle of around 45 degrees.
 
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