The following blog was written by Archer Bravo member Bruce Williams, who hopes we all learn from a flight he was lucky to walk away from…
Some friends of mine won a lottery entitling them to go on a moose hunt in a remote area on the eastern slopes of the Rocky Mountains. With no road access, other than some cut lines, it was important for my friends to see how they could get into the area.
On a warm day in mid October of 1983, they approached me about flying them down to “have a look” at the lay of the land, and maybe spot a moose or two.

I called a local flying club about renting a Cessna 172 for the flight, and as luck would have it, one was available. I told them there were three passengers, and made sure the aircraft wasn’t full of fuel. So far, things were shaping up pretty good.
I then called the weather office to make sure we wouldn’t run into any problems. The forecast called for some clouds at 3000 feet, with a 12 knot wind from the southeast. Nothing too challenging for me as an IFR, multi-engine rated commercial pilot.
We arrived at the airport and I added 10 gallons of fuel, bringing the tanks up to the ¾ mark, as indicated with a dipstick. I did my usual thorough walk-around of the aircraft.
After filing a flight plan, getting everyone aboard, and giving a pre-flight briefing, I fired up the old gal. She purred to life nicely so I taxied over to the run up area, set the brakes, and did a complete run up, following the checklist to the T.
Everything checked out. We lined up on the runway with our take-off clearance, I applied maximum throttle to the aircraft.
I noticed that she didn’t seem to be developing full power, and kept my eye on the gauges to see if I could recognize a problem. After a few moments the RPM’s crept up to 2450, so I relaxed a little and continued the takeoff roll.
The departure was otherwise uneventful, and we climbed to 6000 feet and headed south to the designated hunting area. The air was smooth, and the cabin was full of excited chatter. Little did I know what was about to happen!
About 15 miles east of the hunting area we turned up a river valley to access the zone. I flew directly over the river valley, which put me at 1000 feet AGL. The surrounding hilltops were level with my wings.
After traveling up the valley for a few minutes, there was a fork ahead in the river, with a mountain peak in the middle of the Y. I started to ask my friends which direction they wanted to go, just when I noticed the RPMs had dropped off a wee bit.
I told them we might have a problem, and turned my attention to the issue.
I followed all of the procedures I had learned in flying school: checking the mixture, electrical, throttle, fuel tank selector and carb heat.
The carb heat gave me some concern. When I pulled the lever, there was very little resistance, which in itself was rather odd, and no quick drop in RPMs, as one would expect.
The approaching mountain pulled my focus back outside, and I now had to turn.
The RPMs had continued to drop, and as a result our airspeed bled-off while I fought to maintain altitude. Moments later, the stall warning horn started to squeak, and I knew I had to do something quickly to save the turn.
I lowered the nose and began a shallow bank to the left. We descended perilously close to the treetops, and with the wind sinking off the ridge, we had no place to go but down.
Everything started happening fast, but I knew from experience as a bush pilot that if we were going to survive I would have to hit the trees as slowly as possible. I reached over to drop in 10 degrees of flaps, and at that very instant my left landing gear struck a treetop.
Trees in this part of Canada are roughly 60 to 80 feet tall, and they carpet the landscape, so there was no escaping them. I rapidly pulled my hand back from the flap lever to hold the control yoke with both hands.
It’s difficult to describe how it felt landing in the trees on the side of that mountain. Imagine being on a carnival ride that tosses you upside down, churning at 20 times the normal speed, and you might come close to the experience I had during the last 10 seconds of our flight.
Suddenly, I found myself looking out of what used to be the front windscreen, inside of a forest. I yelled “everyone out”, leaped through the vacant windscreen, and ran 30 feet away from the aircraft. Then I looked back.

I saw three limp bodies in the wreckage and fuel everywhere! Without a moment’s hesitation I turned around and ran back. Two of my friends were awake but dazed, and the third was unconscious with a large gash in his head. The two conscious individuals came out of the wreckage, and after a few moments of shock, one of them helped me get the last person out.

I consider myself fortunate for several reasons. First, I survived a crash in the mountains without a single scratch on my body. Second, everyone else survived the crash with, for the most part, nothing more than some scratches. Third, the fuel did not ignite during the crash. Had it done so, I would not be writing this story.
So what went wrong?
The Canadian accident investigation team, in my opinion, chose to cast blame rather than find the specific cause of the crash. For my part, I offer the following explanation for everyone to learn from.

The above graph shows carb ice can form at just about any temperature all the way up to 105 degrees! And the Cessna 172 uses a normally aspirated Lycoming engine, which can and does develop carb ice in the perfect circumstances.
What is missing from the chart is the ability to “know” when you are experiencing carb ice. The standard textbook explanation is that the engine will start to run rough when carb ice is present, and yes, I have experienced this type of carb ice in the past (over Los Angles actually, on a very warm day).
However, what I learned subsequent to the crash is that an engine can run smoothly and the RPM can drop off substantially at the same time. This is like to leaning the engine too much (as the fuel outlet port is cut off in the venturi).
During emergency procedures I had pulled the carb heat lever out and pushed it back in relatively easily. There was no further drop in RPMs or any roughness from ice melting in the carburetor. This leads me to believe that the carb heat linkage cable was broken prior to the crash and thus the carb heat lever was not connected to the engine.
However, that was not noted in the accident report. And when I asked investigators if they had checked the linkage, they gave each other a puzzled look, and couldn’t recall who inspected that portion of the plane.
No. Mother nature didn’t help. Had the prevailing winds for that part of the country been in existence that day we likely would have had an updraft, not a downdraft, from the ridge. And the outcome could have been totally different.
As with most accidents, these issues stacked together to create a memorable experience. I continued flying, raised two children, and have a relatively normal life through the grace of God and a lot of good luck!
You can email Bruce at bruce.williams@telusplanet.net.
Chris Archer Blogs by ABA Members bruce williams, carb ice, cessna 172, rocky mountains