I was camping with my 170B this past weekend at Red's. We walked over to see the crashed Commander at Minam Lodge. We heard the story 3rd hand. We were told the pilot took off at 2PM in the heat of the day. The pilot borrowed the plane from a friend. The plane was loaded with passengers and luggage. The plane ran off the end of the runway never getting off the ground. We later saw the plane getting a helicopter ride.

After seeing the crashed plane, we saw another pilot fly over to Reds from Minam and then add his passengers. That looked like a good idea.

Here I was thinking you were in Australia! JK First lesson: Don't loan your preciuos aircraft to a friend. Sad, hope no one was hurt.

I spoke with a couple of the passengers at La Grande Oregon shortly after it happened. It seems they were loaded up pretty heavily, and attempted to depart during the heat of the day. The pilot decided to abort the takeoff when it was apparent that the performance wasn't adequate. There was not enough distance to stop given the marginal traction available for braking. There were no injuries.

Scolopax wrote:I spoke with a couple of the passengers at La Grande Oregon shortly after it happened. It seems they were loaded up pretty heavily, and attempted to depart during the heat of the day. The pilot decided to abort the takeoff when it was apparent that the performance wasn't adequate. There was not enough distance to stop given the marginal traction available for braking. There were no injuries.

At least he got the abort part right. Moral: know thyself, know thy airplane's performance. Glad the abort worked.

Cary

Kudos to the pilot for realizing the plane wasn’t up to the take off, and double kudos for accepting the over run (and possible crash) at ground speed rather than proceeding into the likely fatal consequences of crashing at ground effect flying speed.

Cary wrote:
At least he got the abort part right. ...Glad the abort worked.

Cary

I agree the pilot recognized AN abort point that meant the crash was lower energy. Big KUDOS for that. Breaking off a takeoff in mid roll takes cahones.

However, the ‘right’ abort point was shortly after full throttle when acceleration was anemic, at best. And better yet, the “right” abort was missed in pre-flight takeoff calculations that should address runway required, runway available, adjustments for existing runway conditions, DA, aircraft weight, etc. plus a healthy margin.

It might seem silly to abort if the nose wheel will not come just off quickly, but that is the best place. Or when the elevator won't bring us up into low ground effect reasonably early, but that is the next best place. Loss of zoom reserve before clearing obstructions is a bad place. Lack of obstructions and down drainage egress can make hot and high doable with training and experience in low ground effect down drainage egress.

contactflying wrote:... Loss of zoom reserve before clearing obstructions is a bad place. Lack of obstructions and down drainage egress can make hot and high doable with training and experience in low ground effect down drainage egress.

For a great example of this see “Forever Flying” by Bob Hoover. Only his problems with inadequate TO power resulted from his AvGas powered Shrike being miss fueled with jet-A. We never known when we’ll need just a little extra energy.

PapernScissors wrote:the “right” abort was missed in pre-flight takeoff calculations that should address runway required, runway available, adjustments for existing runway conditions, DA, aircraft weight, etc. plus a healthy margin.

Agreed! Four full grown adults plus luggage should not have been loaded on to that plane for departure from that location on that warm afternoon.

The Cessna turbo 206 pilot who brought them all out had the sense split the load in two. The 206 is a far better suited plane for that mission than the single engine Commander. Many folks seem to believe that high density altitude conditions will make exceptions for them.

PapernScissors wrote:

Cary wrote:
At least he got the abort part right. ...Glad the abort worked.

Cary

I agree the pilot recognized AN abort point that meant the crash was lower energy. Big KUDOS for that. Breaking off a takeoff in mid roll takes cahones.

However, the ‘right’ abort point was shortly after full throttle when acceleration was anemic, at best. And better yet, the “right” abort was missed in pre-flight takeoff calculations that should address runway required, runway available, adjustments for existing runway conditions, DA, aircraft weight, etc. plus a healthy margin.

Determining the "right" abort point isn't easy, especially in a high DA situation. Using the 70/50 rule probably works most of the time, but because its purpose is to give an indication of whether the airplane will fly before the end of the strip, it can't guarantee being able to stop before the end of the strip, as stopping distance is affected by traction, braking technique, etc. I have one of those cutesy takeoff calculators, which works relatively well, but then, I don't frequent ultra short airstrips, either.

I think that one of the things that many pilots just don't realize is how much high DA affects airplane performance, including engine power, propeller thrust, and wing lift. Most of us are accustomed to whatever the usual DA is in the areas in which we fly, but put us in a different DA situation, and we have to relearn what we think we know. I'm really accustomed to DAs in the 6-8000' range now; when I flew out of Laramie, add another 2000'. But it's only occasionally that I fly out of that high a DA now, and it frankly feels enough different that I have to be a little more attuned to the differences.

Cary

Best $30 you will spend if you fly in high DA conditions or non standard airports.

Takeoff Performance Computer Product ID: 2091A Sporty's Pilot Shop.

TD

TomD wrote:Best $30 you will spend if you fly in high DA conditions or non standard airports.

Takeoff Performance Computer Product ID: 2091A Sporty's Pilot Shop.

TD

This one? https://www.sportys.com/pilotshop/takeoff-performance-computer.html

Conservative guy that I am (this is NOT a political statement... due deference to forum rules ) I have one of these too just to remind me of some stuff I really need to think about before I load up and go. Then I double the number that comes out the bottom. Cary made a good point about being current vs proficient in high DA short field ops.

Yep that is the one PaperSissors.

I'm with you. I don't take the numbers at the bottom as gospel. My airplane is at S43 which is 17 ft above sea level so it makes a good place to do a baseline with my plane on the hard surface and turf strip. Take off several times with different weights and note distance. Then made my own mark on the bottom which takes into account a 42 year old airplane and my skills. I then add a comfort factor.

At the end of the day it works pretty well. I have used it in Idaho a few times and get pretty close to actual take off distances.

All that being said I always pick a point down the runway that if I am not off the ground by that point, I pull the power while I have sufficient runway left to stop.

Old pilot wanting to get older.

Not super accurate but for every centigrade above ISA add 120 feet to airport elevation, or 600 feet for every 10 fahrenheit above ISA.

PapernScissors wrote:

TomD wrote:Best $30 you will spend if you fly in high DA conditions or non standard airports.

Takeoff Performance Computer Product ID: 2091A Sporty's Pilot Shop.

TD

This one? https://www.sportys.com/pilotshop/takeoff-performance-computer.html

Conservative guy that I am (this is NOT a political statement... due deference to forum rules ) I have one of these too just to remind me of some stuff I really need to think about before I load up and go. Then I double the number that comes out the bottom. Cary made a good point about being current vs proficient in high DA short field ops.

That's the one I mentioned above.

But the real test isn't what the numbers show, but what can you do with your airplane? That takes recognizing your own abilities, and then changing your answer to adjust to the different environment.

I think the highest DA I've experienced during take off was at Leadville several years ago, in which the AWOS announced a 12,100' DA on a reasonably warm early afternoon. My airplane was light--2 hours burned out of the tanks from Greeley, just me and my 67 lb. dog and the usual stuff I carry: 38 lb survival kit, 12 lb. oxygen set, misc. other stuff (quart of oil, lightweight ladder, small tool kit, etc., total about 15 lbs.). So I was confident of being able to take off, and the runway is long enough that I was confident that I could stop if I wasn't off by 2/3 of its 6400' length. Using the 50/70 rule, I had something more than 70% of take off speed by half way, and indeed I was in the air at just about 4000'. Had I needed to, the remaining 2400' was easily enough to stop.

For all you low landers out there, reread what I just said: "I was in the air at just about 4000'." My hotrod P172D with 180 hp and CS prop normally is in the air with that load at Greeley, where it's hangared, in well less than 1000', with more load than I described. Current temp at Greeley is 82 F, with a DA of 7100', something I'm generally accustomed to seeing in the summer. Note the massive difference in take off performance caused by a 5000' increase in DA!

Cary

Cary wrote:

PapernScissors wrote:

Cary wrote:
At least he got the abort part right. ...Glad the abort worked.

Cary

I agree the pilot recognized AN abort point that meant the crash was lower energy. Big KUDOS for that. Breaking off a takeoff in mid roll takes cahones.

However, the ‘right’ abort point was shortly after full throttle when acceleration was anemic, at best. And better yet, the “right” abort was missed in pre-flight takeoff calculations that should address runway required, runway available, adjustments for existing runway conditions, DA, aircraft weight, etc. plus a healthy margin.

Determining the "right" abort point isn't easy, especially in a high DA situation. Using the 70/50 rule probably works most of the time, but because its purpose is to give an indication of whether the airplane will fly before the end of the strip, it can't guarantee being able to stop before the end of the strip, as stopping distance is affected by traction, braking technique, etc. I have one of those cutesy takeoff calculators, which works relatively well, but then, I don't frequent ultra short airstrips, either.

I think that one of the things that many pilots just don't realize is how much high DA affects airplane performance, including engine power, propeller thrust, and wing lift. Most of us are accustomed to whatever the usual DA is in the areas in which we fly, but put us in a different DA situation, and we have to relearn what we think we know. I'm really accustomed to DAs in the 6-8000' range now; when I flew out of Laramie, add another 2000'. But it's only occasionally that I fly out of that high a DA now, and it frankly feels enough different that I have to be a little more attuned to the differences.

Cary

This! When I started flying it was all within a thousand feet of sea level. I then moved to CO and now reside in NM. Field elevation is about 6600’ and DA in the summer months is rarely below 9k. I flew back to Texas to my little farm strip a few weeks ago and it felt like I was flying a sports car. DA is a giant factor for not only the engine but the wing.