When I started flying, my wife and I made an agreement that it couldn’t be just the two of us flying. Didn’t want to leave the daughter orphan. Now that the daughter is over 21 it’s OK To fly just the two of us.
I guess that's possible but considering that the terrain rises from a paltry 4-5,000' were he lived and worked into the teens within 10 miles, I'd hesitate making that assumption.
Anytime it's hot.
Look back at the chart I posted. Cedar City is about 5500 MSL. On the ground. What would the temperature be for the density altitude to be equal to that? Now consider the accident terrain and how high they would have to have been and what standard temperature is for those altitudes.
I got this from Wunderground weather history for Cedar City on that day, so it wasn't 'hot', but they're starting out somewhat high already:
Standard temp and pressure is 15°C (59°F) at sea level pressure. Standard lapse rate is 2°C per thousand feet, so at 5500' the standard temp would be 4°C. Anything above that and you have DA in play. It's not limited to hot days, just as carb ice isn't limited to cold days.
I should have thought about that. I even have an E6B sitting above my computer monitor. I wonder what the altimeter setting was that day. Gotta start with the pressure altitude according to my directions. Would the [absolute] barometric pressure be the 24.46 in an above post? That would seem close considering the standard barometric pressure lapse rate is averaged to 1" Hg per 1,000 feet, isn't it? So would they have used 29.96 for the altimeter setting?
I fly a very similar DA40 regularly and the W&B posted online is wrong somewhere. It says the maximum gross weight is 2646 lbs, yet the empty weight is 1754 lbs and the useful load is 781 lbs. 1754 + 781 = 2535 lbs.
Did you forget that standard temperature decreases 2C for every thousand feet?
Yeah, I guess that correct based in the definition of density altitude as pressure altitude corrected for nonstandard temperature. But I think of 5500 feet as the same density altitude issue whether the airport is at 5500 MSL or at sea level. IOW, density altitude as performance altitude whether the temperature is standard or not.
Seems to be a dramatic failure of training. I remember my instructor sitting down with me and showing me this video:
Yup, 5500 feet altitude will have the same air density whether it's on the ground at 5500 or in the air at 5500. It's the temperature that makes things get bad. Standard lapse rate means that you can take off at sea level and expect 4°C at 5500 unless the air is very dry or saturated. On the ground at a 5500' ASL airport, the sun heats the ground, which heats the air above it, which reduces its density, and so conditions there are far different than at 5500' ASL above ground that is thousands of feet below you. That's when the accidents happen. Imagine a really warm day at that 5500' ASL airport, like maybe 30°C. Density altitude goes to 8576 feet. How well is that airplane going to climb? How long will that runway need to be? What happens to our horsepower in a normally-aspirated engine? There's a formula for that somewhere, but the C172N POH cruise chart tells me that at 8000 feet, at full throttle, standard temp, I can expect no more than 75% of the HP. Edit: And that's at cruise speed near redline RPM. You won't get that RPM in the takeoff roll or the climb, meaning that the hp is considerably less than 75%.
Hope is not a flight plan? wow.
Every time I watch that video (I've watched it several times over the years) I find myself yelling at the pilot, as he passes landing spot after landing spot, barely out of ground effect, heading for the trees.
I sometimes wonder in how many accidents, the pilot spent much time on sites like this one and others with Accident Forums. A wealth of knowledge to be gained from others experiences.
That's not the accident we are talking about.
