Theodore Cannon 

March 28, 2024

I was inspired to write this document after reading the book Adventures in Aviation by Captain Kimball J. Scribner. Thanks to Dr. Brian Heckman for calling my attention to this excellent book about Captain Scribner’s experiences as a professional pilot. Although I’m not a pilot, I had some unique experiences, which I record here, flying as scientist-observer in the rear seat of the NCAR Explorer Sailplane 9929J. 

The Puker

One hot summer day in c.1972 we were at Jeffco Airport (now Rocky Mountain Metropolitan Airport) near Broomfield CO waiting for conditions to be right for developing CuCg. By lunchtime it appeared that it would be some time before we would need to take off. The groundcrew members and I decided to go into Broomfield for lunch. We decided to go to a Mexican restaurant, where we enjoyed very filling and delicious lunches. 

On returning to the airport, atmospheric conditions were changing rapidly, and we needed to take off right away. Pilot Vim Toutenhooft went through his check list (he was very meticulous about this) and we took off on tow. We soon found uplift under a developing cloud, went off tow, and began flying in a tight circle ascending into the cloud. We ascended rapidly, and my Mexican lunch ascended even more rapidly! Fortunately, we had a supply of Wyatt Urp bags on board! 

Having discovered that my stomach didn’t particularly like our mode of flying, I visited a physician and got a couple of prescriptions for motion sickness which helped considerably. I also refrained from eating large lunches (especially Mexican) before flying.  Interestingly, I discovered after I flew on several subsequent days the motion sickness progressively became less bothersome each day. 

Descending With No Place to Land

One summer day we took off from Ft. Morgan airport. Somewhere west of Ft. Morgan we encountered updraft and Vim released from the towplane. Vim suggested that we put on our oxygen masks, which contained microphones for communicating with each other, the ground station and air traffic control.  Vim’s microphone did not work, so he suggested we should exchange masks, as it was not so important that I use my mike. 

By the time we had exchanged masks, we had lost any lift. To complicate matters, there was an east wind, which was blowing us away from Ft. Morgan. There are no airports between Ft. Morgan and Centennial Airport, the other closest airport. We were too far away for us to make an airport landing. I kept looking at the ground which we were approaching rather rapidly but didn’t say anything. 

About this time Vim said for me to look at a beanfield almost directly below us. He said we were going to land there! Sure enough, Vim landed there with the skid directly between two rows of beans. I don’t think he damaged more than a couple of bean plants during our landing.

I noticed a farmer was doing some kind of operation on our port side. He looked up and saw 29J in his field. I thought “boy, he is going to be pretty upset having an aircraft in his beanfield”.  Instead, he came over all smiles. This was probably the most exciting thing that had happened in Masters, Colorado for some time. (Masters is an extinct town in Weld County Colorado).

Vim called the ground station and told them of our plight. The ground crew came out and disassembled 29J, loading it onto a special trailer we had for that purpose. I think we destroyed more bean plants in the process of taking the sailplane apart and getting it onto the trailer than we did making the landing. 

These Dive Brakes Don’t Work

In addition to the Cloud Particle Camera, I always carried a color film camera for photographing clouds and optical effects that I could observe out both sides of the canopy. Although my field of view was quite limited, I was able to get some quite spectacular and interesting images, many of which I still have to this day. 

One time we had completed taking cloud data and were headed back to an airstrip. I was just enjoying the ride when I noticed that I had hung the camera next to the dive brake control knob. Dive brakes are control surfaces that can be extended from the wings and are used to increase drag, thereby reducing airspeed. They are essential for making a controlled landing and stopping the sailplane at the appropriate spot after landing.

Upon seeing the camera’s location, I immediately took it off the control knob and informed Vim of my error. Vim said he had noticed that he couldn’t move the dive brake control but didn’t want to worry me, so he hadn’t said anything! All was fine then, and we made a safe landing. 

Film Developer Foot Wash

We flew out of the Ft. Morgan airport a couple of summers (1972 and 1973) as participants in the National Hail Research Experiment (NHRE). I stayed there in the Best Western Motel. I was using an electric Nikon F camera as the film transport and shutter mechanism components for the Cloud Particle Camera (CPC). This Nikon accommodated a special back that held extra- long rolls of film. This specialized camera was available commercially at the time. I purchased film in 100-foot rolls, then, in a dark bag or dark room, loaded one-third of the roll at a time onto reels in the camera’s film canisters. So, each roll of film was about 33-feet long, enough film for about 80 exposures.

For film processing, I had purchased a stainless-steel kit consisting of two concentric processing tanks and a spiral film holder that just fit into the tanks.  The tanks were about two-foot diameter. Following each flight, I was anxious to develop the film so I could examine the images for their scientific content as well as to determine if there were adjustments and/or improvements I needed to make to the CPC.

The first time I developed the film was on a hot afternoon. I used my hotel bathroom as an improvised dark room. I set the two tanks on the bottom of the bathtub, then filled one with developer, the other with fixer. Each tank took about two gallons of chemical. After preparing the chemicals, I made certain to have opaque tape, the exposed film canisters, spiral film holder and timer ready to go. I then closed the bathroom door and, after adjusting my eyes to the darkness, made the room light tight using towels and tape to seal the door. There was no air conditioning in the bathroom, and it was so hot in there that I stripped to my shorts.

The first process was to load the film into the spiral film holder. This was a very tedious process. While pulling the film from its canister, I had to hold the film by the edges and carefully work it into the gaps between the spiral wires. I had to do all of this by feel, as it was completely dark. If I made a mistake and missed a gap, I would discover it at or near the end of the film. If two layers of film were touching, the film would not develop properly. I used the toilet seat lid, and my lap was a worktable. Finally, after much sweat and effort I had the first 33-foot roll properly loaded into the spiral holder. It would only hold one roll at a time. 

Now I tried to place the holder into the developer tank. The bottom of the bathtub was not flat, and the developer tank was slightly warped due to the weight of the developer plus tank, so that the holder would not go into the tank! This required that, while holding the holder, I had to get my fingers under the heavy tank and lift it carefully while working the holder into the tank without exposing any of the film to the developer. Finally, this was accomplished, and I started the timer while rotating the film in the developer. 

The next trick was to transfer the film into the fixer. I pulled the film out of the developer but could not get it into the fixer tank because of a similar warp in the fixer tank. In desperation, while holding the film reel, I stepped into the developer so I could get my fingers under the fixer tank. I was finally able to accomplish this, start the timer, and finally wash the fixer off the film and my feet using tap water. I then removed the film from the reel and hung it on the shower curtain rod to dry.  Mission accomplished after several hours of hard work and a pair of developed feet! 

Today, out of curiosity I tried in vain to find one of these large film processing kits on the internet. There are Russian kits (Lomo USSR) that you can use to process long rolls of film of various widths, but I have not been able to find the stainless kit that I used in Ft. Morgan.

Severe Turbulence

On June 23, 1972, we were ascending inside a growing CuCg near Kimball Nebraska. The cloud developed rather quickly, and we started seeing lightning nearby. Vim decided to exit the cloud. On exiting the cloud, I felt the sensation of weightlessness. Based on the variometer output recorded on a strip chart recorder in the ground station, Vim and Jim found that we went from 20 meters/sec. up to 20 meters/sec. down within seconds. Upon exiting the cloud, Vim planned to land at Sterling Colorado, but we received information from Dave Younkin in the tow plane that there was heavy rain and lightning there and landing would be impossible. We were at 7.2 Km. altitude.  Vim then made the decision to fly to Sidney NB which was roughly forty miles away. We made it to a safe landing.  Imagine my wife’s surprise when I called her and told her we had landed in Sydney. Fortunately, we didn’t have to make another out landing. 

From Vim’s June 23, 1972, log, flight 2:

We now found very smooth 10 m/sec lift that lasted for some time until suddenly, in a split second, there was turbulence. The aircraft was out of control with apparently no pressure on the controls. We made some violent gyrations but felt no strong acceleration. Loose objects like my maps, gloves, etc. flew through the cockpit. I immediately opened the dive brakes and tried to stop the aircraft rotation. The airspeed began to build up. (I believe to ~100 MPH) and I suddenly found myself out of cloud, in a spiral dive. We recovered and flew a little way away from the cloud for pictures. The cloud had an overhang to the east, showing fresh development in an unusual way. Dave Younkin reported from Sterling airport that the cloud looked very threatening from there and he advised not to land at Sterling, so we headed for Sydney, Nebraska.

Acoustic Airspeed Indicator

On occasion, Vim would let me fly 29J from the back seat. We would be flying in smooth air after taking data. I could only see out of small sections of the canopy to my left and right. Air flowing over the canopy and four struts created a very noticeable noise. I used the pitch of this noise as a sonic airspeed indicator. If the pitch increased, I would pull back on the stick to raise the nose and reduce airspeed and vice versa. 

This sound, characteristic of 29J with the CPC in place, was discernible from the ground. When I was at the ground station, I could always hear the ship approaching for a landing, even if it was hundreds of feet off the ground. 

Epilog

I sometimes muse about how I would develop instrumentation for getting in-cloud particle data using today’s technology. I wish I could start over again. First, I would use a high-speed digital camera. To get in situ data within a defined volume I would use two, color flash lasers. I was developing the two-color system when my work at NCAR was terminated. I would then mount this camera on a drone and fly it in cloud from the ground.  Today’s computers could analyze the images in real time and determine which images were from the in-focus volume. Doing an internet search, I have found several developments of in situ imaging since the 1970s. I consider the CPC work I did as pioneering research instrumentation and hope future scientists will use my work as inspiration to further develop this technology.