zero.one.victor wrote:Remember, you're not making a 180 degree turn- you're actually making about a 270. 180 to go back, then 45 more to get back on the runway centerline and 45 back to get aligned with it again.

This little factoid has probably caused as many turnback crashes as the stall-spin scenario! The solution is to get in the habit of turning 20-30 degrees away from the runway heading after lift-off, preferably to the side AWAY from the taxiway, if there is one. This will get you into a better set-up for a simple 180 without too much last minute correction.
Also, if there is any crosswind, always turn away from it so your turnback can be made into the wind.

When I used to tow gliders, this was SOP, and anyone practicing a rope break was happy we did that.

As far as bank angles, we were taught that 45-50 degrees was the best compromise between altitude loss, increased stall speed, and seconds required to make a 180. Gliders, because of their slow stall speeds and low sink rates, can easily make a 180 with 200 feet of altitude in a 45 degree bank, including the rollout.

Powered aircraft are a different story, and while lighter, slower planes like Cubs can get close to the performance of a training glider like the 2-33, heavier craft like a fully loaded 206 or 185 need a whole lot more speed and altitude for this manouver, and pattern altitude for them is not too far off the mark. I need a minimum of 75 kts in a 50 degree bank and 800 feet to complete a power off 180 at a gross of 3200 lbs, and I better have just the right offset, because I'll be rolling out of the turn in the landing flare! Bank angles of more than 50-55 degrees in a power off turn would get me around faster but they are just too dangerous in my plane at those weights....I'd rather not be lined up than mush in or God forbid actually stall it!

If you don't practice this on a regular basis, assuming you WILL land straight ahead until you have 1000 feet or turned crosswind is pretty good advice for 182's and up. If you do want to practice, start at 1000 feet with a 300 foot offset and no more than 45 degrees of bank. Check the altimeter and airspeed on rolling out until your performance is consistent before shaving off 100 feet or increasing the bank. There is really no need to do this practice at the minimum possible altitude. If you pretend the runway is 300 feet higher than it really is, you will learn everything you need to know about what your plane will do in a real emergency. Whatever you do DON'T STALL!!!!!

Rocky

Jr.CubBuilder wrote:

a64pilot wrote:

Jr.CubBuilder wrote:

Savannah-Tom wrote:

a64pilot wrote:

Mr. Ed wrote:2G's...You're assuming that you are trying to maintain level flight. When you unload the yoke at 60 degrees you're not pulling 2G's.

Unless I'm wrong it's not maintaining altitude, but maintaining airspeed that will require the 2G's. I've been wrong before, but I think I'm right here.

You are right. It applies to "unaccelerated" flight. You can be going up, down, or level, but you can't be increasing or decreasing your speed. This is basic physics.

tom

??????????????
Ok, I gotta mull that one over for a bit, I have a sense you are right but I'm not seeing it from the right angle.

If I kick over to a 60 degree bank and maintain my airspeed I must be pulling 2 Gs

I think so. I know it's true for level, unaccelerated flight, I think it's true for just unaccelerated flight as well. Of course the same theory says a 90 degree bank is infinate G's and therefore impossible, but we have all done it? The only real point was don't get slow trying not to lose altitude and then crank in a lot of bank to turn quickly, just be careful.

Ok, the grey matter was working while I slept. That's right if you maintain level flight, but only level flight.

If you crank the wings over to a 60 and let the nose drop you can maintain the 60 degree bank without pulling any more Gs, and if you maintain your airspeed (but not altitude) you should be at one G.

Pushing the nose over means you are accelerating towards the ground. You have relieved part of the load on the wings by allowing the aircraft to "fall".

This pretty fun, we've got a huge green quote section going. Can we fill a page?

tom

Savannah-Tom wrote:

Jr.CubBuilder wrote:

a64pilot wrote:

Jr.CubBuilder wrote:

Savannah-Tom wrote:

a64pilot wrote:

Mr. Ed wrote:2G's...You're assuming that you are trying to maintain level flight. When you unload the yoke at 60 degrees you're not pulling 2G's.

Unless I'm wrong it's not maintaining altitude, but maintaining airspeed that will require the 2G's. I've been wrong before, but I think I'm right here.

You are right. It applies to "unaccelerated" flight. You can be going up, down, or level, but you can't be increasing or decreasing your speed. This is basic physics.

tom

??????????????
Ok, I gotta mull that one over for a bit, I have a sense you are right but I'm not seeing it from the right angle.

If I kick over to a 60 degree bank and maintain my airspeed I must be pulling 2 Gs

I think so. I know it's true for level, unaccelerated flight, I think it's true for just unaccelerated flight as well. Of course the same theory says a 90 degree bank is infinate G's and therefore impossible, but we have all done it? The only real point was don't get slow trying not to lose altitude and then crank in a lot of bank to turn quickly, just be careful.

Ok, the grey matter was working while I slept. That's right if you maintain level flight, but only level flight.

If you crank the wings over to a 60 and let the nose drop you can maintain the 60 degree bank without pulling any more Gs, and if you maintain your airspeed (but not altitude) you should be at one G.

Pushing the nose over means you are accelerating towards the ground. You have relieved part of the load on the wings by allowing the aircraft to "fall".

This pretty fun, we've got a huge green quote section going. Can we fill a page?

tom

The real question is how long before we tick off the moderator?

Yeah, you got it. No level flight no 2 G's. You can do a complete 360 degree roll at 1G.

Mr. Ed wrote:Yeah, you got it. No level flight no 2 G's. You can do a complete 360 degree roll at 1G.

As long as there is no change of direction your right, that makes it unaccelerated flight. I've been thinking a little also, can you make any kind of turn without some G in excess of 1G? Don't count a hovering helicopter now.

Jr.CubBuilder wrote:But then again I think I'll just not worry about it.

I think I'm about there myself. Do you mind company?

GumpAir wrote:
Practice away because it's good to be in that mindset every take-off, but don't get it spring loaded in your head that you're going to have the room for anything, except aiming for and hitting the least expensive thing you see directly under the nose of the airplane.
Gump

Gump is absolutely correct. There are just too many variables when it comes to engine failures on T/O to set a hard altitude that will allow you to make it back to the runway. Unless the conditions you have during an actual engine failure are exactly the same as you had when you practiced your engine failures, that "hard" altitude is useless. The decision has to be made based on your best judgment at that time, not some magic number you see on the altimeter.

Matt

I think the stats back up the land straight ahead folks in terms of good outcome and survivability. And that's single engine and piston multi-engine.

Somehow, in all the years, I've never had a prop stop completely on me, except for shutting one down in cruise in a C401, which was a non-event.

But still, if I was looking at landing deadstick from low altitude and no reaction time, I'd want to be wing's level, in control of MY fate with ME setting my descent rate and ability to flare with airspeed and flaps. Not screaming out of the sky in a tight, possibly high G turn at too slow an airspeed to arrest the descent. Stalling onto a concrete runway from 50 feet up will kill you faster than flaring into rocky ground under control at 35 KTS.

Gump