My plane consistently takes off from a 3-point attitude in approximately 400 - 500 feet in most situations, with the exception of density altitude above about 6000' or at gross weight. It peels off of the ground indicating 38 - 42 mph and manages to accelerate through 60 mph in a second or two for a reasonable climb out of ground effect and is then ready to maneuver with decent control authority. The ASI indicates essentially nothing before that point. I have grown comfortable enough with its takeoff and landing performance to fly it in and out of seven and eight hundred foot long fields where no fifty foot obstacles exist. The performance is reliable and predictable enough that I count on the fact that I'm getting out of there, and this approach has served me well thus far. Taking off seems the only option once you have enough speed to actually make the call. This sometimes seems to be living a little on the edge, but we count on our engines to power us through situations every time that we fly over steep rugged terrain and usually on climb out as well.

I have heard rules such as you must have 70% of your takeoff speed by mid-field, otherwise abort takeoff. This is obviously not practicable when you can't really indicate 70% of takeoff speed, and you most likely couldn't get stopped without a wild ride heavy on the binders through bumpy dirt, grass, rocks, etc... It seems the takeoff can necessarily be absolutely committal in some short field scenarios, but it works out fine if you trust your equipment and use good judgment, even though sufficient margin for changing your mind doesn't exist. Has anybody developed any strategies or know of any effective rules for aborting a takeoff from a short field where so little time defines the difference between wise precautionary action and potential disaster?

Wiley Ranch on the south fork of the Salmon. The pic doesn't do justice, but as soon as you leave the parking space, you are committed to takeoff. Maybe look at the angle of the trees near the runway. I agree with the sentiment that we really do rely on our engines,etc. to keep us out of the trees and bushes - especially when we start to flirt with the limits of equipment capability. Familiarity with the craft is important and the more familiar you are, the more likely you will pick up on something before you get to the point of no return. Don't brush off those stumbles in the engine, etc that could be clues to maintenance issues. And as always, maintain your aircraft well.

Scolopax,
A good question and when we discussed it this weekend, I thought I had my answer......Then leaving bend, a 5200ft paved airport, I had a wake up call. We had been flying off of short rough stuff all weekend. It was even pretty warm most of the time and even though the msl was relatively low (~1000ft) the density altitude was fairly high with 80 deg. temps we flew in.

Bend is at 3500ft and the air temp was in the 90's. I had been doing maximum short field departures all weekend out of necessity so when leaving bend, I waited for 40mph indicated and pulled full flaps, just out of habit I guess (and I knew you were watching, so why not ). When I think back on it, it took a split second longer to get to 40mph than usual, and the airspeed indicator seemed to be a bit erratic. When I pulled full flaps, the airplane became airborn and climbed about 20 ft agl but then started settling. As you saw, It settled all the way back on the runway and then finally began to fly and climb.

If this had happened anywhere else that we had been departing, it would of been game over.....

From this, I realized that just because the airplane will become airborn, does not mean it is ready to fly and climb. Seems to be an energy issue. One must attain enough energy to safely depart a given area at a given temp.

Anyway, it would be great to get Mauleguy's opinion on this topic, as he seems to regularly use all the available turf plus some water to get airborn. One must have a really good feeling for your airplane to do this.

The wind was a bit erratic at bend sunday. The sock was limp when I started my role, traffic seemed to be switching the direction they were landing periodicly while I was there. Maybe I got a bit of a gust on my tail? Not sure.

Seems that to safely abort a takeoff on a very short strip, you must make the go/no go decision immediately after you put the throttle in. If you are accelerating like you know your airplane will need to for the given distance, then you go. If not, you pull the power and wait till it cools, make two trips with less weight etc.

Interesting topic.

I THINK BOTH OF YOU HAVE IT PRETTY WELL NAILED
The thought of 70% or midfield in some(most) situations are great, BUT they have no business in your decisions if you are flying near the edge of your envelope!
There are times when you push the Ball to the wall that you have made your decision! Period
That is why we can fly into the short field and the ridge line, or the old logging road.
When you are on the edge of that you are not looking at the asi or anything else in the cockpit! If you are you shouldn't be!
You have to have your head, eyes, ears, hands, feet and your butt all reaching for any clue to tell you what is going on!
If your motor quits or coughs or any of a hundred different things happen you have to make the best out of possibility of a real ugly situation! You made the decision to take off when you landed? Or why else would you be there.
If you don't push the envelope a little you will never find the edge!
Some people like to stay along way from the edge and that is just great.
Some people like to explore what they can and can't do, The hope is to not bend anything, and if you bend it, maybe not break anything,ETC.
Lets just hope the learning curve is not a 90 degree turn??
Have as much fun as you can stand, or afford.
Happy flights
GT

I'd say that while I do not know him personally, I do know where he used to operate and what is involved in doing so.

Any advice that M6RV6 is willing to give regarding short field operations with a loaded aircraft is pretty sound.

gb

A couple thoughts to ponder:

These are just opinions, so take them for what they are worth.

I suspect a lot more planes have been wrecked dilly dallying around wondering weather to abort or fly out a take off or landing, than actually poorly executing one.... If you made a good solid decision to fly it off, make it fly don't second guess yourself...

I try not to couple short field with max climb unless I have to.... first short field first.... then max climb. Some are going to say it won't always work, and no it probably won't always work but 99% of the time, you will have time (and a better chance) if you don't leave ground effect until you absolutely have to. Look at the typical ag op. Although not in the same context, by definition, virtually every take off is "short field" for them, because even at most municipal airports, by the time they reach flying speed (loaded) they are out of options for an abort... you will have to fly, and lumbering out of ground effect before she is ready is going to hurt...

Most folks would be amazed how quickly their airplane will accelerate to a safe flying speed, if you just roll the nose over once airborne...
highroad, at 20' you were probably nearing the end of the road (ground effect wise) for your craft. Had you rolled over the nose, once free of terra firma, you would have gained safe flying speed and been able to initiate a far better climb, and probably sooner than the end of the runway (were in this case you were probably still wallowing your way out)

BTW...Ground effect exists, to at least a lesser degree above dense vegetation. Just 'cause your strip ends at the start of dense Tamaracks doesn't mean you are out of ground effect there. It will still be there above the tamaracks.... just not as cushy...climb enough to clear the trees and then level off, stay low over the trees / bushes until it flies right and then again initiate your climb...Just watch out for the dead / stray branches

Popping full flaps does a great job of "popping" the airplane off the ground, leaving full flaps on in most airplanes does a great job of producing drag (read: slowing you down) the sooner you can safely start milking off the flaps, the sooner you are going to be building speed...

fire away....

Take care, Rob

Excellent topic and critically important to have a very good understanding of all the aspects before making that decision to take off. As stated, depending how short the short field is and your aircrafts performance given the current conditions, the option to abort may quickly disappear.

Another very important thing to knowingly consider before deciding to take off is the wind. How gusty or shifty is the wind and secondarily is there a significant wind gradient as you climb. Does part of the take off or climb out have wind changes caused by objects or terrain. How much cross wind, if any, is there? My Citabria does not have flaps so I have that plus and minus. But flap management is very important in conjunction with the wind conditions.

Understanding and using ground effect, as stated, is very necessary in such situations. Getting off the ground and into ground effect quickly reduces the rolling drag. And then staying as close to the "ground" as is safe, will maximize the ground effect benefits. My experience has been that the three point take off gets me off the ground fastest but then rotating to level and staying right on the deck works best. Then getting to 75 mph or more I can pull up rather sharply out of ground effect without loosing airspeed.

Another area I have been considering and trying to prove out in practice is how much more effectively I can maximize my short field take off with getting my cg as far aft in the envelope as I can.

I'll go at this one more time, Here's a little exercise to learn about your take off, and aircraft. As said above get off the ground and get the nose pointed back towards terra firma and utilize everything you can.
So back to the exercise?? Have someone watch you take off at your best. Hopefully you will be pointed somewhat into the wind, best is if you have a quartering headwind from the left.
Now get all set up again for take off but point your right wing down the runway, bring in all your power as quick as you can and turn and fly it off the runway, have someone watch and mark where you left.
Now do it again with your left wing pointing down the runway, bring in the power like you want to get off of the ground!
When you are just starting to turn towards the runway come in with all the right rudder you have, if you time it right just about the time you get turned down the runway you have enough authority with the tail to keep it straight??
Now the tricky part is to go ahead and let that p factor or what ever anyone wants to argue what it is, turn you into the wind just a little, now here is where I'll pick up the most noise!! let the upwind wing raise a little and keep the nose down and crab just a hair still using lots of rudder to make it all work. Now as I said in my opinion earlier, so far you should have not looked inside the airplane once yet!! You will be off the ground but you are definitely not flying yet!!
You have just found the true meaning of ground affect!
This is not just for taildraggers, when I got my first Bonanza, Orin Hudson told me to try a few of these things, but he made me promise I wouldn't go out and kill myself?? I did this with an E model and it would get off the ground lite in about 250-300', but you used the next 200 to get up to airspeed to fly away! but you were off the ground!!, Now a high wing aircraft has less ground affect just because the wings are farther away from the ground. When you start you shove of the ball forward, you have to do it with authority and really mean it as you should be committed when you do! The yoke should be all the way back the rudder all the way right and it should stay there until you have to move it.(get the tail down, get the most angle of attack possible as quick as possible)
Now again this is my opinion, I have the right to it, just as you have to yours
If you feel like it, go try it out, if it helps great, if it doesn't you learned that it did not.
Either way you went out did a little something different with your aircraft and hopefully learned something about it and yourself.
Now next time it's blowing hard and nobody really wants to go fly?? go out and practice,it's the best time to learn, way better than having to learn because you have to get back on the ground!
Everyone says never land with a tailwind?? Some place you have no choice, Go practice a little
start slow and see what it's like. You might just some time have to choose into the setting sun direct down the runway?? or land with a tailwind. It's not hard, it just takes practice so there are no surprises.
And please don't hurt your plane or yourself!!
I apologize for the rambling, but I think I'm ready to come back to civilization soon and talk to some pilots.
OK now I'm done, time for bed, Everyone have a great time in the air and enjoy, be safe and have as much fun as you can stand or afford!
GT

Rob wrote:
Popping full flaps does a great job of "popping" the airplane off the ground, leaving full flaps on in most airplanes does a great job of producing drag (read: slowing you down) the sooner you can safely start milking off the flaps, the sooner you are going to be building speed...

This type of scenario, popping the airplane off the ground using a lot of flaps and then milking them back off to a max.performance climb config. is one of the big advantages of the STC upgrade that I've just gotten approval on. In a max. performance situation exactly like what you're discussing... being able to have full, proportional, delicate, convenient and immediate control over the flaps becomes a big issue for safety. Popping off the ground fast and then not being able to overcome the flap drag is bad news. Not being able to conveniently "milk" the flaps back up creates a situation where some pilots will "dump" them all at once back to 10 degrees, with a resulting "dip" or loss of lift.

I like to let my airplane fly itself off the ground. Then extra horsepower does the rest. If the runway is not long enough to do that I have no business being there

Kenny wrote:If the runway is not long enough to do that I have no business being there

You may be missing out on a lot of what Idaho back country flying is famous for (and what makes us big city folk jealous as hell)

Kenny wrote:Nose dragger is not the same as knuckle dragger

LOL ! I'm proud as hell to be a Neanderthal tailwheel knuckle-dragger (even though my current airplane has the tailwheel mounted on the wrong end)... Keeps my feet from becoming atrophied on landing

M6RV6 wrote:So back to the exercise?? Have someone watch you take off at your best. Hopefully you will be pointed somewhat into the wind, best is if you have a quartering headwind from the left.

This is not just for taildraggers, when I got my first Bonanza, Orin Hudson told me to try a few of these things, but he made me promise I wouldn't go out and kill myself?? I did this with an E model and it would get off the ground lite in about 250-300', but you used the next 200 to get up to airspeed to fly away! but you were off the ground!!,

Only thing I would quibble with is a crosswind from the right is much preferable in my Bo. I have approx 30% more horsepower than you did in your E35 so have a lot more torque and P factor to overcome. The wind blowing on the tail helps me out there.

Bman, go give it a try, Start out with the yoke in your belly and shove the ball quickly but start out with your foot all the way to the floor on the right rudder. It will suprise you.
It worked with my Machen S model with the TIO540 J2bd engine 350 hp. But once off of the ground I had to pull some power because I could not keep it from coming on around to the left.
Go give it a try and PM me.
GT

I will try that. I really can't start with the yoke in the belly because if the nose wheel comes off the ground at too slow an airspeed the plane is going left and I can't stop it.

Bman,
Full right rudder, full right aileron, pointing just right of the runway centerline about 30 degrees, And the ruddervators have flaps on them if you use a lot of down trim. You can get the tail all the way to the ground and get that Bonanza wing to work slow at a high angle of attack it will really surprise you what you can do! It takes almost the length of the airplane for it to roll all the way back, even if you just get it to roll back and put the tail almost to the ground and get control of the aircraft then slow it down and gather your wits and see what you just did. It took me a long time to make it all work right.
Have fun, GT
By the way, that Machen S Model was the only plane besides the 18 I wish I would never have let go!!

I've seen a Machen. A real bastard child as no one wants a Lycoming in a Bonanza.

Lots of good stuff here. When to abort on a short field departure? Hmmm.... It seems the consensus here is in many cases in true short field situations the decision to "abort/commit" immediately follows: throttle to the firewall, smoothe running engine, maybe a quick glance at oil pressure. Obviously the best tool here is familiarity with aircraft in many different environments. (practice, practice). A short field is no place to be wishy washy in our commitment to the departure. I wonder how many pilots have got cold feet after leaving the ground seeing those tree's looming ahead and in the last half of the departure run had abort/commit/abort/commit thoughts shoot through their heads screwing up what would have been a safe departure (maybe on the edge) only to find themselves in the tree's.

I'll never forget a time when I was younger (16 or 17) when myself and two of my friends (one quite big and heavy) were with my dad in a rented 172. Four of us in a 172 on a hot summer day. My dad didn't have a ton of hours in a 172, but he did have a ton of hours in a lot of different airplanes. Flying was his life. One thing he did know....was himself. This was back in the 60s and he decided to land at the grass strip at Vashon Island. Tall tree's at both ends. Forget how long at that time. But not long. Time to take off. Pile in, taxi down the driveway for more runway. Hmmm.....hope this works. Glance at my dad. Total confidence. Throttle forward, we begin to move a little. On the actual runway now, moving faster. (thinking of my fat friend in the back seat ). Very glad my dad is in the left seat. We eventually leave tera firma, but those tree's are looming ahead and we arent near the tops. I dont say a word. I do take a sideways glance at my dad. He has that rock solid look that I have seen many times before. Total confidence, and total commitment. I hear a wack as some part of the airplane hits one of the tree tops as we weave our way through the tallest ones. After we are back in cruise mode I ask him: "So, dad.....you think we could have gotten off any sooner than that?" "Nope".

I have no doubt that my dad had decided to see this departure through as soon as he decided to taxi down the driveway to gain a little more advantage. And after full throttle with a smoothe engine the commitment was complete. By being so commited to the departure he was relaxed and clearminded, and was able to milk every ounce of takeoff performance that was available to him that day without getting wishy washy at the most critical time. Was it the wisest choice to go into that strip with a grossed out 172 on a hot day. Maybe not. Some would argue that the wisest choice would be to never fly when there is no margin for error. Then again I have friends who think I'm nuts for flying in the first place.

Remember that song that goes: "If lovin you is wrong, I don't wanna be right"
Anyway, not sure what this adds to the thread here. Think I'll go flying.

whynotfly wrote:..... We eventually leave tera firma, but those tree's are looming ahead and we arent near the tops. I dont say a word. I do take a sideways glance at my dad. He has that rock solid look that I have seen many times before. Total confidence, and total commitment. I hear a wack as some part of the airplane hits one of the tree tops as we weave our way through the tallest ones........

"Total confidence"? No offense to your dad, but that story reminds me of the signature of one of the guys on the supercub site: "often mistaken, but never uncertain" or something similar. That can-do attitude is great until all of a sudden it turns out you can't do-- then things go from yeehaw to awshit in a big hurry, but it's usually too late to do anything about it. Better not to cut things that close, esp with pax on board.

Eric

Eric you have a valid point, and that's why I qualified the scene with "maybe not, the wisest choice."
Would I go into a short grass strip with a grossed out 172 on a hot day? Easy decision for me,..."No". But its hard to argue with over 30,000 hours flying many types of aircraft into Alaskan weather back when forcasting and IFR equipment etc. were tenuous at best with NO accidents. None. Zippo. He's 93 now and still flying. Just lucky?.....Maybe.

hello