Summertime and the crashing is easy

July 3, 2008 by Bruce Landsberg

With apologies to Lyricist George Gershwin and singer Billie Holiday, the livin’ ain’t so easy as density altitude climbs. In the last few days we’ve had a couple of accidents that sure look like density altitude, although it’s too soon to say for sure.

Whenever I see high temperatures and high terrain I’m suspicious. When a high performance aircraft that is typically a strong performer at lower density altitudes is fully loaded, I’m almost ready to put money on it.

The two fatal accidents that appear to fit the DA profile both happened on June 29: In Santa Rosa, NM a Cessna 206 with 5 passengers was lost shortly after takeoff. One state over, at the 7,000 foot of a mountain close to North Las Vegas, NV, a Cherokee 6 also with five passengers crashed. We’ll learn more as the investigation goes forward but if this is the case, to lose 10 people in one day because the pilots forgot that sea level performance doesn’t exist in the summertime is sad, expensive, and really unacceptable.

My experience with hot and high makes me conservative on who and how much to carry. Trip legs are frequently shorter as fuel load is lightened and I really study the route carefully so as to be at altitude before getting to the high terrain, if that’s possible.

Leadville, COSome years ago when taking a mountain flying course, while pausing at Leadville, CO to get the certificate for being at the highest airport in the U.S. , I watched a fully loaded Cessna 172 almost do the deed. The airport picture makes it look deceptively easy. The Skyhawk is not exactly a ball of fire with all seats full at sea level. With a runway of 6,400 feet, that’s less than the field elevation of 9,927 feet msl the Cessna pilot clearly did not understand what he was up against. With four people on board the Cessna rolled and rolled and rolled. It sagged off the ground, caught its breath in ground effect and then sagged some more into the the cool thin morning air. That coolness was the only thing that saved them because by early afternoon there would have been no climb at all – only forward and down.

If you haven’t done much high terrain flying recently take a look at ASF’s mountain flying course.

As we did in talking about near fuel accidents, share your experiences that you or a “friend” had in learning about density altitude beyond the academic view. Is there a way we could be teaching this more convincingly?

Bruce Landsberg
President, AOPA Foundation

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17 Responses to “Summertime and the crashing is easy”

  1. Brad Isaacs Says:

    I believe the Piper was an Archer with all seats full. It was on a cross country from N. Las Vegas to San Francisco Bay Area. There are ? reports of buzzing.

  2. Eddie Nunez Says:

    Mr. Landsberg:
    We have a product that airports should install , it is call DAD .I can send you details e mail me at eddien@aeroinfoinc.com. IIt shows pilots density altitude prior to departure as they go on the runway.

  3. Gene Royal Says:

    I’ve had two HDA experiences, both in 1977 with my Cherokee 6 260 – one of 7 airplanes I have owned since 1975 for a total of 2600hrs. One at ABQ with 6 passengers, do not fill tip tanks written on the fuel order but checked only the mains; and the other at Santa Fe at dawn when it just wouldn’t climb out of ground effect with just pilot and one passenger.

    At 74, I decided before a recent trip from California to Florida and back in my 177TRG that upon return I would “hang it up” after a good, blessed run. I landed in Mojave 4/15 and haven’t flown since. The Cardinal is for sale.

    I would be happy to write up these stories if told where to send them.

  4. L. Emberland Says:

    Instructors should be required to take students to a high altitude field on a hot day so they can experience first hand the effects of density altitude. The pilot’s operating handbook is not enough and not reliable because of performance degradation for various reasons. Nothing replaces experience when it comes to learning an important lesson.

  5. Bill Hebert Says:

    In May I got to do a real cross country, experiencing lots of high DA take-offs and landings. Our trip was in a Cessna 182P with three people, baggage and 80 gallons of fuel. We flew at gross on take off from Concord, CA to Dallas, TX and back. Over night both ways in NM at KAEG (Double Eagle II) in Alberqurque.

    I had taken the AOPA online Mountain flying course, and received three hours of dual in mountain flying. One key item that isn’t covered very well is actually trying to fly at altitude in the summer. We all stress take offs and landings, but after the take off, just trying to fly at 10500 feet, with OAT at 24C and pressure at 28.83 presents another challenge.

    Kinda like a special VFR take off. We talk bout the limitations of SVFR take offs, but don’t often address what you do after you leave the airspace!

    Our most surprising moment was leaving Midland, TX (KMAF) in the afternoon. After KAEG (5837 ft.), KMAF seemed like it should be a breeze at 2871 ft) and a 9500 ft runway. And the take off was. Though we were only 500 AGL at the end of the runway in the 104F temp. Climbing to altitude and maintaining it, was another matter. Here we discovered thermal soaring in a 182. Using the heat from the freeways to help us climb!

    Also flying over NM and parts of AZ where ground level is 7000 ft or so, maintaining altitude presents issues. Now add some thermals and one is in for a fun ride.

    I think we stress crossing mountains, but don’t stress high desert flying, or even high altitude flying on hot days enough.

  6. Rudy Schroeder Says:

    I’m 78 now, but back in 1965 my friend and I left Burns, OR in my C 140 with full tanks and 400 pounds of he and I headed for PDX. It was a hot day and we managed to maintain 200 f/min climb to 7000 F as we approached the south side of Mt. Hood. I then noticed the VSI showing a rate a climb of 1000 ft/min. We were in mountain wave at 7000 and going up like an elevator. We took advantage of the free ride to about 17,000 where we called it ‘enough allready’. I put the nose down to max manuvering speed and headed west. With PDX in sight in the distance, I called the tower and told them my position and altitude and ask for a straight in. The controller gave the OK and asked me how I got that thing up to that altidude. Not wanting to tie up the frequency, I told I would tell him after landing. That was a fun ride thanks to a mountain wave near Mt. Hood. That was then when I was young and healthy and O2 for a short time at 17,000 wasn’t a problem.

  7. N Smith Says:

    Pilots like me who earned their rating and cut their teeth in low elevation locations such as Houston, TX are taught about how to deal with high atitude flying, but there’s little practical experience dealing with it. As hot as it gets here in the Gulf Coast area, we’re still rolling down runways sitting at 100′ MSL or less. The low elevations allow less conscientious pilots to “get by” without really respecting the issue.

    My first true high density altitude experience was a trip in my C-152 to Raton/Crews field in NM (elev 6,352). That was the first time I actually needed to use the “lean for max RPM before takeoff” procedure I book-learned 4 years prior during Private training. (Everything went fine, and I enjoyed the scenery flying over Angel Fire before heading back to Houston). My point is that we all learn it, but many pilots don’t regularly deal with it, so it’s not a critical part of their preflight procedure.

    That NM trip was about 15 years ago. My second high density experience was just months ago departing in a twin Piper out of Abilene, TX (1,775 MSL). A humid 95 degree ambient temp combined with a shorter than usual runway (2,900′) produced my first aborted takeoff roll (with about 2 feet of runway to spare once I got the beast stopped!). Even with partial fuel and one 200lb soul on board (me), that runway threshold was coming at me a bit faster than I was used to. Taxiing back and leaning for max RPM produced much better results. Interesting that leaning occurred to me immediately as a new pilot 15 years ago, but this time it took some pucker factor for me to remember. “Lean for max RPM” is now a standard part of my pre-takeoff checklist.

  8. Ken Kokjer Says:

    Some years back I flew my TriPacer (PA-22, 135hp, cruise prop) from Fairbanks, AK to Arapaho County just south of Denver. The trip down was uneventful. Leaving Denver was planned for early morning, but somehow that never really happens. So with two small adults, full fuel and lots of camping gear, we took off at about 95 F. The runway is long enough that I knew I could attempt to get above ground effect and still put it back down. The plane actually climbed out of ground effect fairly well and so we headed east. However, it would climb no further. So I headed for the interstates and rode the thermals to get enough altitude to cross the hills to the east, from where it was downhill all the way to our next stop in Nebraska. A good lesson learned without trauma, fortunately.

  9. Gary Justus Says:

    Bruce,
    I had such a density altitude problem many years ago. It is told on the Colorado Pilot Association’s website in the June 2006 issue under communications. I tried to post a link here but that effort failed.

    Gary

  10. James L. Solberg Says:

    Bruce

    I have used a Koch chart to help in determining aircraft performance for high DA conditions. I used it extensively on a three week trip from Eau Claire, WI to Alaska and back with a friend. South Lake Tahoe was one of our stops on the way back and the Koch chart used in conjunction with my POH accurately predicted the performance of my Mooney 201.

    Jim

  11. Charlie Kollar Says:

    Prescott Az. with 7000 feet of runway is not enough in a Piper Arrow on a August afternoon, no wind and three passengers. After ground effect the airplane would climb 100 ft. a min. The rising terrain provided a great view of pools and the floats in them. A 180 was in order back toward the runway with the tower not being surprised at the request. The home base is Danbury Ct. DXR with a field elvation of 458 feet.
    Reading about denstiny altitude for flat landers needs to be taken very seriously.

  12. Jeff Culwell Says:

    Flying on the southeast coast, we have lots of experience with hot & humid, but not too many airports with high elevations. Prior to a trip out west, which included a planned trip to Bryce Canyon (elev 7890 MSL), I decided to see just what kind of performance I could expect. I chose KBQK – a near sea level airport with about the same runway length as BCE, on a hot day and restricted my takeoff power to the 22″ which was all I could expect at BCE. That was an eye opening experience, and helped reinforce leaving there at dawn! I still remember landing at BCE at lot faster than usual, even though the airspeed indicator was on my usual approach speed.

  13. Robert Guinn Says:

    A few weeks after I received by pilots license, I flew to Cameron Park in CA to meet my Mother and my Aunt in my 172SP and take them for a ride. This was my first flight with passengers. It was 101 degrees when I landed. I did a mental calculation of how much fuel I had on board and how much my Mother and Aunt weighed and it all seemed to work in my head.

    When they arrived by car at Cameron Park, my Cousin was with them. Without thinking, I loaded all of them in the airplane along with their purses, cameras and whatever else they had in their hands. I was nervous about flying passengers and about being a new pilot and not thinking straight.

    During takeoff, my acceleration was poor and about 3/4 down the runway, I realized I had a serious problem. My 172 was doing 60 knots but was barely lifting off the runway in ground effect. I continued to try and take off. Once the departure end of the runway passed about 10 feet below the wheels I was not sure at all if I was going to be able to clear the hill at the end of the runway. I kept the nose down and stayed in ‘climbing ground effect’ right up the hill and over the top. I was able to climb at about 50 to 100 fpm and found some cooler air. I spent the rest of the flight thinking about how I’d nearly killed my family and about my coming landing. I felt that I had one chance because I was too heavy to go around.

    The landing was uneventful. I did a proper weight and balance and density altitude calculation after I landed. I asked for each of my passengers actual weights and used my dipstick to calculate fuel weight adding back in what I’d used during the short flight. During my quick ‘mental’ calculation prior to the flight, I underestimated the weight of my two expected passengers, did not add in the weight of my unexpected passenger and underestimated the amount of fuel I had on board. I was over max weight on takeoff for a 172SP under any conditions.

    It’s for me to really call this a learning experience because of the total stupidity of what I did.

    A few months later I was flying my new 182T back from Independence KS and I stopped in Laramie WY for fuel (first fuel stop btw). Taking off from KLAR (elev 7284), I was surprised at how much runway I needed and how poor my climb performance was. I wasn’t over weight, but I was really disappointed in myself for jumping back in the airplane and taking off in hot/high conditions without looking over my numbers. While I was en-route, I pulled out my new POH and found there was no reason to be surprised. The airplane did exactly what the POH said it would. The representative from Cessna asked me, right before I took off in my new airplane, to not bring negative attention to Cessna by flying away from here and making a smoking hole in the ground.

  14. Bill Howard Says:

    HI all -

    I did hear some mention of leaning in some of the responses – but not in others. On a cool day in Butte, MT, my Cardinal RG with two on board and full tanks just wouldn’t out-climb the terrain until I pulled back the mixture – all of a sudden, I had a NEW PLANE! Years later, my Beech Sport (150HP) with my wife and myself aboard could barely outclimb the rising hill to the south even WITH the mix leaned on a warm afternoon. The fully loaded Cessna 421 ahead of us on the taxiway warned us to ‘stay back – I’m gonna do a full-power run-up!!” He didn’t do much better than we did! BE SAFE – LEAN!

    BeechSportBill

  15. Jack Says:

    Years ago I was in Breckenridge and remember watching an Alaskan bush pilot take off in a cub(?) on a hot summer day. Unfortunately he used up the entire runway and crashed without taking off. If I remember right that was the last official flight at that particular airport.

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