Carb heat

One of my first-year college roommates was from New York. His father was an air taxi pilot for a major airline. Following in his dad’s footsteps, he was taking up flying lessons at the airport in Denton, Texas. The thought of a teen piloting an airplane was completely foreign to me at that time and thinking about it I felt a little intimidated. A couple of years passed and that “fear of flying” made me mad at myself, so I decided it was time for an introductory flight to face my fears.

The fee for a 30-minute introductory flight 1971 was $10, so I scheduled an appointment and went to an airport just outside of Dallas. After about 30 minutes of introduction to flying in the instructor’s office, we went outside to board one of his two his Cessna 150s. Both were old, but the one whose tail number ended in “Juliet” was a little newer than the one ending in “Romeo.” Juliet had wheel pants, Romeo did not, and both had coffee grinder comm radios.

After the instructor described what he was doing as he performed the pre-flight inspection, he emphasized the importance of a checklist. He explained everything from startup through run-up and takeoff until we left the pattern.

I was handed the controls soon after takeoff. A gymnast in college, I was already confident in my ability to easily learn a new coordinated skill. Carefully following instructions, within minutes I could make coordinated turns, hold altitude, and keep controlled flight. I was also thoroughly enjoying myself and thinking it was too easy. I flew the entire flight since just after takeoff.

Cessna 150

The Cessna 150 started many pilot careers.

After reentering the pattern on the downwind leg, the instructor told me to cut my throttle. He said we would glide in and eventually complete a “full stall” landing. He explained that a full stall is when the plane’s wings would lose the ability to keep lift and fall from the sky. He had me turn base, then final, and then asked if I wanted to try and land. Since flying seemed so natural, I said, “Sure, just tell me what to do.”

He explained the flare as we lined up on final. He explained that just before we got to the runway, I would have to pull back on the yoke to raise the nose. Thinking about the concept of a powerless fall out of the sky with the nose high made no sense to me. I told him if we were falling and raised the nose, it only makes sense that the tail section would hit first. He tried to reassure me it would not, but the combination of my ignorance and stubbornness caused me to eventually give up as we neared the pavement and yield the controls back to him for the landing.

With the stall warning screaming, the plane finally gently touched down on the mains and then the nose wheel soon after. Failing the landing concept challenged my ego, especially since I was wrong about the tail having to hit first. It created an unresolved conflict with what was otherwise a very pleasant experience, so I signed up for lessons to get my license as soon as we got back to his office.

At that time, I could buy a 10-hour block of time, including fuel and oil, for $100. If the instructor went with me, it would be another $5 per hour. (Do the math: a private license in 1971 cost just north of $500.)

Flying truly was “love at first sight” for me, and while it was going to be a squeeze on my budget, a new pilot was born. I still love everything about it, from pulling the plane out of a hangar, preflight, the takeoff, radio communication, navigation, landing, FBOs, ground personnel, other pilots, and the overall friendly feel around an airport.

My first solo was June 8, 1971, after 7 hours of dual. My instructor weighted around 210 pounds to my 140 pounds. That old Cessna 150 used to eat up over 1500 feet of takeoff roll before a struggling liftoff with my instructor on board. On my first solo, that same 150 seemed to jump off the ground shortly after applying full throttle. The new adventure and enjoying what I was learning more at the airport than at college was pure fun. I flew my first solo cross country a few weeks later July 7, 1971, after a total accumulated solo time of only 3.9 hours.

The solo was from Arlington, Texas, to Hillsboro, Texas, about fifty miles southeast of Arlington. The outbound flight and the landing in Hillsboro were uneventful. I had my logbook signed off by an FBO operator at Hillsboro, took a break while I drank a soda, and then boarded the old Cessna 150 to make my return flight to Arlington.

I was about ten minutes into my return flight when my previously smooth sounding engine suddenly significantly changed in sound. At the same time, there was a noticeable loss of power. The new sound was constant, but the engine was not running smooth. I was able to keep altitude at a slower speed, but for how long? My instructions never included whether the pilot could do anything other than to aviate, navigate, and communicate until safely landing the airplane, hopefully at an airport.

I had a modest upbringing with two loving, old school Italian parents raised during the Depression who often told me, “You can do anything if you set your mind to it.” Because there was never any extra money, I learned out of necessity that if I were fortunate enough to have something of value, if it broke I could either fix it or do without. My favorite “toy” became a shiny chrome Crescent wrench because I could completely disassemble and reassemble my bicycle with it, and other equipment.

Lawnmower

A “fix it” mindset learned from tinkering with lawnmowers can come in handy as a pilot.

By the time I was a teen my mother would often say, “My son can fix anything.” This included a bicycle, lawn mower, motorcycle, automobile, faucet washers, toilet valves, the tube TV and radio, everything else around the house.

Being able to fix anything is not from supernatural skills. I think most people could do it. It does require patience (OK, that would drop most people), using the senses to see and recognize the problem, experience remembering what works and what does not, but mostly having the confidence to try in the first place.

I also learned that both worry and panic are negative distractions preventing one from focusing on “the solution” and reducing the ability to think clearly and resolve a problem. While I live by the “plan for the worst, hope for the best” philosophy, being mentally prepared to attack a problem with confidence is extremely important when confronted with unanticipated circumstances, especially when seconds count.

So, there I was, a young 21-year-old man with little flying experience, now concerned that one could not simply pull over, get out, raise the hood, and try to figure out what was wrong. The good news was that the problem did not appear to be getting worse, therefore it seemed like I had time. I did not have an autopilot and letting go of the controls in an old Cessna 150 is like letting go of a kite string, but I had to try to do something. The throttle was responsive, but it was no help with the unusual sound and diminished power. Rechecking the panel, all instruments were still comfortably in the green.

I noticed the knob of the carburetor heat in the full-in position and against the panel where it should be. I learned to apply carb heat only when reducing the throttle to avoid carburetor ice, like when landing. I was reluctant to pull it out, but since nothing else presented itself to be the cause of the problem, I decided to try it.

I gradually pulled it at first while listening for a change, and then slowly until it was all the way out. Nothing different. I pushed it all the way back in. Again, nothing different. I expected the change in sound and power I had always experienced, but this time it made no difference in performance or sound. What I also noticed was that it did not feel right. It was easier to slide than normal. The resistance that should have been there was absent. I concluded the problem could be something wrong somewhere with the carburetor heater.

I had sufficient altitude and could not see traffic in any direction, so I was able to further investigate my suspicions about the carburetor heat cable. I could not look to see, but by reaching underneath the panel I could carefully feel around behind it. I felt wires and cables and allowed my fingers to gently advance toward where the back of the carburetor heat cable should be. I felt it, but it was too thin. It was not the thick spiral steel jacketed shroud that should be there to protect the cable, like the cable on the hand brake of a bicycle. It was a thin single strand of bare steel cable. I carefully followed it away from the panel back with my fingers, periodically pausing to look up and out the window to make necessary corrections for level flight on course. I finally found the large part of the cable shroud that surrounded the cable several inches from the back of the panel.

Carb heat

Don’t forget the carb heat knob.

I grabbed it and gently pulled it toward the panel. As I pulled the shroud forward, the carburetor heat knob came out on the cabin side of the panel, as if someone were pulling it out. While firmly holding the cable shroud against the underneath side of the panel with one hand, I pushed the carb heat control knob back in with the other.

I could feel the previously absent friction as the cable slid into the sheath. The normal sound and performance of the engine was at once restored. When I let go, the cable slowly slid out of the shroud again. Knowing that this is what caused the problem, I felt again for the shroud. The connection end of the cable shroud was much larger than the shroud behind it. I slid my fingers farther away from the shroud end until I found a nut hanging loose around the spiral shroud. I slid the nut along the shroud back to the close end of the shroud. I then pushed the cable shroud toward the back side of the panel where I was able to thread the shroud nut onto male threads I found on the back of the panel. I tightened it as much as I could with my fingertips. I could then push off the carburetor heat and it stayed off.

I concluded the airplane’s vibration caused the cable nut to gradually loosen, eventually disconnecting from the threads. This allowed the shroud to slide away from behind the panel, acting as if one intentionally applied carburetor heat by pulling the carb heat knob out from the panel. How long did it take to loosen the nut enough to disengage? Your guess is as good as mine.

I resumed my first cross country flight without further incident and safely landed at my base airport in Arlington. I told my instructor what happened and suggested that the carb heat cable needed to be tightening to prevent it from vibrating loose again in flight.

I continued my instruction and gained my license a few months later. I still love to fly, although not as often as I want. I had an incident in-flight, continued to fly the airplane while calmly searching to find the cause of the problem, and then found a solution, reinforcing what my mother always used to say.

Al Cercone
Latest posts by Al Cercone (see all)
11 replies
  1. Lawrence Zingesser
    Lawrence Zingesser says:

    A very interesting story.
    If the “fix-it” mentality hadn’t prevailed at that time what were the landing option available?

    Reply
    • Al Cercone
      Al Cercone says:

      While the power had diminished with the carburetor heat engaged, I was still able to maintain altitude, so the need for an alternate place to land was not eminent. But, had it become necessary, much of the flight path between my home airport and my cross country airport paralleled a major divided interstate highway, and while not perfect with its own list of negatives, it is always an emergency option. There were also a few small municipal airports scattered within a reasonable distance of my flight path. Thankfully, this time, I didn’t need one.

      Reply
    • Al Cercone
      Al Cercone says:

      Mike,
      Good catch!

      As I obviously too often rely on “spell check” than “the words of our youth”, mistakes more frequently go unnoticed.

      Reply
    • John
      John says:

      Mike,
      Al like myself is more into fixing mechanical things than spending time on the correct spelling of hangar or hanger. But thanks for pointing it out after 50 years of flying I still get the spelling wrong most of the time I suspect. The main point of the story is a low hour pilot (at the time) fixed a problem that could well have ended up and a forced landing. Well done Al.

      Reply
  2. Phil
    Phil says:

    Excellent story. You were so young and had so few hours that it’s remarkable that you sorted that out. Sounds like you were, and are, a natural born pilot. My dad taught me the same attitude that if you don’t panic, there is almost always a solution to everything, given enough time. Logical, clear thinking and knowledge of your aircraft (or car) systems definitely are the biggest ace in the hole. Along with the willingness to get your hands dirty and figure things out.

    Reply
  3. Don W.
    Don W. says:

    Good job on the carb heat cable Al! $15/hr instructed wet… Those were the days. I started instruction in 1972 at the tender age of 15, and the local flying club had Cessna 150s, and a few Piper 140’s and 160’s for primary instruction. The C150 was $11/hr wet, but the instructor went for $4/hr, so the total was still $15/hr. Minimum wage was $2/hr so it took about a day of stacking hay bales to afford an hour of instruction. Ahh youth!

    Reply
  4. Frank
    Frank says:

    Great story of problem solving and calmly thinking through the problem. How times have changed though. I recently completed my private at > $5,000. I think most pilots today would not solo cross country with such low hours and “instructions never included whether the pilot could do anything other than to aviate, navigate, and communicate.” I had training on all the emergency procedures and significantly more hours prior to my solo x-country.

    Reply
    • Al Cercone
      Al Cercone says:

      It’s good to hear the initial flight instruction now covers more bases. I guess the prices are all relative to the times, and ten times the cost 50 years later might be somewhat in line.
      My first job in the early 1960’s was working at a minimum wage of $1.25 per hour. I paid 25 cents for a gallon gas for the car. A couple of buddies and me would pool our pocket change for enough gasoline to drive around all night.
      A lot has changed. The last time I flew a Cessna 172 out of Dallas Love Field, the cost of fuel cost alone was about $70.00 per hour.

      Reply
  5. Dave
    Dave says:

    Al, most of these good comments have not focused on your “I can fix anything” mindset. It was this that enabled you to “keep your cool” and rather than throw up your hands in defeat opting for a hazardous emergency landing, you used your hands to seek out the problem and solve it. I have the same mindset and am astonished when I see people simply give up rather than seek a solution. You said that you feel most people could be fixers. Over the years I have learned that most people who have a special talent underrate it, thinking, “it must be easy for everyone else since I can do it,” so I understand why you say that. But it was our Moms that recognized and encouraged it, and we happened to fertile ground for developing “it”. Great story, well told, thank you.

    Reply

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