Presumably, the bounty hunter was acting within the law and the ‘arrest’ he performed was not a ‘kidnapping’.
General Aviation aircraft are not an ‘unsafe mode of transportation’.
A PA-28 Cherokee Arrow (not Arrow II or Arrow III) seems to have a maximum useful load of 1,120 pounds. Arrows can carry 48-gallons of fuel. Avgas weighs six pounds per gallon, so 48 gallons of fuel weighs 288 pounds – leaving a payload of 832 pounds. (lNB: I don’t know the amount of unusable fuel, so I’m using the whole 48 gallons). I don’t know the amount of drainable oil. I think the PA-28-180 takes 8 quarts of oil so there’s 15 pounds, leaving 817 pounds for the passengers, baggage, etc. If the bounty hunter weighed 400 pounds, then the pilot, passenger, and everything else can add up to 417 pounds. If the pilot and prisoner were not obese, and if the baggage was moderate, a PA-28-180 should be able to climb with the load that was carried on the accident flight.
At sea level. On a cool day. A heavy airplane at a high density altitude… Well, we saw the result.
ETA:
I don’t have time to look up the weights and capacities of Turbo Arrows. Thanks for the link. I’ll read it later.
I’ve never seen any variation in airspeed in turns from 90 to 1080 degrees. It stays the same, which isn’t really a surprise as the plane is flowing with the air mass as it flies.
Turning isn’t that fast, a standard rate turn takes 60 seconds to complete 180 degrees. 2 mins. to 360. I would guess there are some wind sheer conditions out there that might cause a plane to stall, but that’s not really because of a direction change.
Aircraft also (usually) take off into the wind when they’re using a runway. On a ship, or on the ground, you need to get the air over the wings. In flight, you already have air over the wings. Whether you’re flying with the wind, against the wind, or anywhere in between, you keep the same airspeed. Ground speed varies.
I understand that you are flying in the bubble that is the wind speed around you. But wouldn’t a very hard turn into a 20 knot head wind require some additional adjustments over just flying in calm air? Wouldn’t that turn cause you to lose more altitude than one in calm air?
As you turn, the aircraft has no idea anything has changed because it’s still moving through the same air mass and part of that air mass. It’s like the air mass is motionless, except it also moves you across the ground.
A turn will of course lower a planes altitude. But it does not mater if your going into a headwind or have the wind behind you? It will be the same altitude change? (assuming exact same input from the pilot). So during the turn, either with or against the wind (say 20 knots). As soon as you turn, you get out of the bubble of what you are traveling in. Or perhaps it’s minutiae and really doesn’t matter.
Hey Johnny LA, have you read Chicken Hawk? It’s a great book about Helo pilots in Viet Nam.
No. The plane knows nothing outside the air it is moving in. Doesn’t matter if that air is moving at 500 knots or 0 knots over the ground. The plane moves in the air, what the air does relative to the ground is irrelevant to the aerodynamics.
It’s a common enough misconception that even some pilots have unfortunately.
The bubble, as you call it, is 100s of miles across. The plane is flying wholly within the airmass and doesn’t feel any effects from the air’s movement over the ground. It isn’t minutiae that doesn’t really matter, it just doesn’t exist, any more than you walking across the surface of the earth is affected by the earth moving through space at a gazillion miles an hour.
Edit: I’ve also read Chickenhawk, a great book. Earnest K Gann also wrote some excellent books focused on the early days of airline flying.
That sounds correct but it’s obviously oversimplified or gliders wouldn’t work. Obviously the first error in what you are saying is while the plane isn’t affected by ground speed directly, the plane still feels gravity, and thus the movement of air relative to that gravity vector is relevant.
The whole premise of this thread in the first place is that a plane is maneuvering in confined terrain. As already noted, air flows are disrupted and do funny things in places like that. So it’s entirely possible that, just in the distance from one wing-tip to the other, you could have air moving in different directions (vertically as well as horizontally). The whole process of large uniformly moving air masses simply doesn’t apply to this conversation.
Banking a plane increases the angle of attack on the down-going wing (only while the plane is actually rolling, not after it’s rolled to where the pilot wants it), increasing the chances of that wing stalling. But encountering an updraft that lifts just one wing and not the other, can do the same thing. Gliders, especially high-performance ones with their 18-meter wingspans, are especially susceptible to stuff like that.
When flying a plane in a crater, all bets are off.
Ok. A plane fighting for altitude into a head wind will not lose altitude when it makes a hard 180 degree turn out of the wind (other than the normal altitude lost in a turn). It doesn’t lose lift with the wind now blowing from behind it. The plane would have lost speed in the turn, and now the wind is behind it. I’m talking about an emergency, all you can do turn. And a small GA aircraft.
…I’ll look for more of Gann’s books. Thanks for your input.
I would just like to point out that there is NOTHING to indicate the guys in the crater either stalled or spun in. Indeed, the visible wreckage, with the fuselage laying along the ground rather than nose-first like a lawn dart, looks more like CFIT (controlled flight into terrain) rather than a stall/spin. That, and both men survived, which is unlikely in a low altitude stall/spin.
So many errors here. Banking does not increase the angle of attack of the wing. Angle of attack is controlled by the elevator, or the trim, which is used to compensate for the *loss of lift *due to the bank. A continuing bank condition without backpressure on the yoke is the beginning of a graveyard spiral.
The plane does not fly into or out of the wind. It is PART of that wind. If the wind is blowing 100 MPH, and the plane is flying at 100 mph directly into it, the plane is perfectly happy, even though someone on the ground would say the plane is motionless. Now the plane turns so that the 100 MPH airflow (wind) is behind the plane. It’s still in the same air mass, totally oblivious to what the air is doing with respect to the ground. But the observer on the ground would think the plane was moving at 200 mph through the air. Not true, the plane is still only going 100 MPH through the air.
You seem to be thinking the wind blowing over the ground has some effect on the airplane. It does not. Pretend the ground is invisible. If the wind is strong enough, you could going 100 mph through the wind and actually be backing over the ground. Or going some other angle to the ground. Neither the wind nor the aircraft knows this or cares.
The trouble starts when the pilot can see the ground. When learning to fly low & slow in a light airplane to be able to do pipeline patrol or other flying very near the ground that you have to know that the track over the ground has nothing to do with what is happening to the airplane. The most common problem is the turn from base leg to final and needing to be aligned with a very specific track on the ground and then you have to adjust when you start and how you complete that turn. If the air mass is moving any direction other than straight down the runway, each turn will need to be adjusted for the air mass movement and if there is a cross wind, your heading on final, any leg of the approach actually should be adjusted to compensate for this.
Ground reference maneuvering while inside a moving air mass and needing to make a track in reference to the ground all the while flying a small, under powered airplane like a C- 150. Be very careful.
It is not a plane problem or a wind problem, it is a pilot problem.
Nitpick.
No really a grave yard spiral, could most likely be a normal descending turn. If I am turning from down wind to base leg or base leg to final and am using back pressure, I am trying to correct bad planning and piloting and that is when I crash.
It’s not relevant from an aerodynamics point of view. If you are talking about gliders using thermals to gain altitude, then that’s really a navigation issue not an aerodynamic one (i.e., vertical navigation).
My comments all assume a stable airmass. If the air is turbulent then you get various effects on the airspeed as you move through bits of air that have different velocities. These still don’t manifest as a loss of airspeed or lift from turning from a headwind to a tailwind though.
I think you’ve misunderstood Senegoid here. While in the act of rolling, the wing that is moving down will have a higher AoA than the wing that is moving up. Once established in the bank, it is as you said.
Yeah pretty much.
Assuming you start from straight and level flight, when you bank, the lift vector tilts to stay perpendicular to the wings. If you do nothing else then the vertical component of the lift vector is smaller resulting in a loss of altitude. In a normal turn you would use some up elevator to increase the angle of attack of the wings and therefore the size of the lift vector. The goal is to increase it just enough that the vertical component is the same as when you were flying wings level so that you don’t lose any altitude. The increase in lift comes with an increase of drag and so if you don’t increase thrust you will lose airspeed. The steeper the bank, the more severe all of these effects are.
This all happens whether you’re turning into out or out of wind. The movement of the air over the ground is irrelevant provided it’s a stable air mass.
The trick with trying to out climb terrain is that you are already at max lift and max power. Any turning you do will cause a loss of vertical component of lift and increased drag. With no additional power available to compensate, the only thing you can do to maintain a safe airspeed is to lower the nose a little which has a further detrimental effect on lift. So you need the widest, most gentle turn you can get away with in the space available.
The wind does have various affects on the aircraft, but it’s all to do with changes in the airmass, AKA turbulence and wind shear, and trying to navigate with reference to ground features (ably covered by GusNSpot
).
