This is the second installment in a two-part series about the NSF/NCAR Electra aircraft, which was retired last year. Since 1974, the durable four-engine turboprop had carried researchers and their equipment around the world, collecting valuable meteorological data and contending at times with severe weather.
The NCAR Archives has established an Electra Oral History Project to capture the memories of those who worked with the aircraft over the past three decades. Last month, SN Monthly published excerpts from interviews with two retired Research Aviation Facility staffers: engineer Norm Zrubek and pilot Lester "Bill" Zinser. Here are excerpts from interviews with RAF flight technician Kurt Zrubek and MMM scientists Peggy LeMone and Don Lenschow.
In the early 1970s, all member countries of the World Meteorological Organization agreed to implement GARP, the Global Atmospheric Research Program. Its first field project, the GARP Atlantic Tropical Experiment (GATE) in 1974, was a huge undertaking involving almost 4,000 participants from 70 nations. The Electra was one of 13 aircraft involved in the experiment. Peggy LeMone, now a senior scientist in MMM, provides these recollections.
|Peggy LeMone. (Photo by Carlye Calvin.)|
It was a big international experiment, maybe the biggest well ever have. There was an array of ships stretched across the entire Atlantic Ocean. In the East Atlantic there was what was called the "A-scale" array, which was a big hexagon, and then within that was the "B-scale" array, which was a smaller hexagon. What the aircraft would do was fly out to the B-scale array and document the convection to the detail possible at that time. Flights were also designed to study the boundary layer and radiation.
When you flew a coordinated pattern, you would have several aircraft at once. If you were flying through what we called a cloud clusterwhich, if you are looking down from satellite, what you see is a big white blob that is basically the anvil of the cumulonimbus clouds underneaththe aircraft would be flying through the cloud to get in situ data. We had some radars, but we had no airborne Doppler radar at the time. And we had radars on the ships, but again it was not Dopplerized. So we would get the wind field through these storms, and if they were two-dimensional we would just fly a linear pattern across the storm. We would just go back and forth at different levels across the line. If it was a more complicated pattern of clouds we would fly what we called the "butterfly pattern," or what the hurricane people call "figure 4." Then there were patterns where aircraft would fly around over a large area to get the convergence into that area. A typical flight through a storm would have the DC-6 [operated by NOAA] at the lowest level, the Electra somewhere near cloud base, [and other aircraft would fly higher].
Sometimes there were some very funny blind-men-and-elephant stories. Observers on airplanes at one height would say, "Were not seeing anything!" and observers on airplanes at another height would say, "What do you mean, this is really exciting!" You wondered if you were in the same atmosphere. So it was always fun to go back and compare notes.
It was fun. We generally started flying in the early morning, and did missions during the day. Scientists and crew on the Electra ate C-rations. "One meal, inflight, individual" was on the cover of the C-rations, so we would follow with, "With liberty and justice for all!" As an alternative to C-rations, Ed Zipser had bought Breakfast Squares, which are pretty awful. That was our fare on the Electra. We would typically be seated at a table about a yard wide. There would be two of us at a table, and each of us would have a microphone, and wed take notes. In those daysthis was before we had the nice software they have now over at RAFwhen we did a sounding wed have somebody reading off numbers and somebody plotting. I remember Jeannie Kelly [of NCAR] would often do this. We would always have a student on board to help plot data, for soundings and stuff. We had blank maps with ship positions, latitude, and longitude on them so you could keep track of what was going on during the mission.
An Electra mission would last about seven hours. And then wed come home and get debriefed in the afternoon. And then wed typically stagger back to the hotel, go out to dinner, and start the next cycle the next day.
I think we tried to alternate days on and days off, and basically Bill Pennell, Bob Grossman [both of NCAR], and I rotated in and out as chief scientists on the Electra. We were also part of the pool of people who served as airborne mission scientist or mission scientist, in which case we wouldnt fly on the Electra. On occasion, one of us would fly on the Queen Air, which was used for missions near Dakar [Senegal]. We ended up working about two days out of three, with the third day spent looking at data, doing laundry, or resting.
We arrived in Dakar about June 8, and left around September 24. It was basically all summer. We were the lifers. I mean, some of the people got breaks, but we [people from NCAR] basically stayed the whole time.
|Thats a gust probe on the nose of the Electra in this file photo taken during an overseas field experiment.|
Kurt is RAFs Instrumentation Technician Group supervisor. For the past ten years, he has been a flight technician and crew member for field projects with the Electra and C-130, as well as the NSF/NCARs King Air (now retired).
|Kurt Zrubek. (Photo by Carlye Calvin.)|
Ive always loved to fly. The Electra I always considered my airplane. It was my favorite aircraft to work on. It was very dependable, comfortable, and relatively easy to instrument, and a wonderful aircraft to fly in. . . . The airplane always performed pretty flawlessly.
Its exciting to look outside the airplane and see a tornado off in the background. Some flights are very smooth. I mean you can go out there and you can sit and drink a cup of coffee all day long and never spill a drop. And there are the other onesboy, you dont want to get out of your seat. . . .
The highest Id ever been on the Electra was 29,000 feet. It was on a lidar project over the North Pole [for University of Illinois professor Chester Gardner]. We were flying from Resolute Bay to the pole in order to obtain the first measurements of middle atmospheric temperatures and Fe [iron] densities. Mind you, this was a very empty cabin. All we had was a lidar system, and there were probably about six crew in the back, plus the three up front, so it was not much in the way of weight in the airplane. That was my first trip up to the North Pole. It was fun to see the inertial navigation system turn over to 90 degrees north. We flew there, I think, about three to four times for that project. The Electra had to be specially modified for the large lidar ports and was the ideal platform for that project.
You work with so many different scientists. Its never the same thing twice with our job. Well sometimes get the same people back, but its really never the same experiment twice. You always go to different places in the world and meet new people. . . .
One problem with the Electra is that it is an old airliner. It has hat rails across the top of the airplane. And one problem we had is, whenever we put instrumentation in the airplane, we had to do something with the wiring. A lot of the wire was run underneath the floors, but then a lot of the signal wiring and power wiring went up into the hat racks. So, we had to find innovative ways to wire the aircraft for field projects. What does all this mean? It means that space was at a premium in the airplane, so we had problems sometimes with placement of equipment. We filled the coat closets and the baggage pits with instrumentation. What we always tried to do was find the most effective means of installing equipment, laptops, personal luggage, and things like that. . . .
Science is changing, and technology changes with it. With the advent of HIAPER [the NSF/NCAR High-performance Instrumented Airborne Platform for Environmental Research], we will be in our fourth or fifth data system renovationa new, faster data system. We travel more in the field now. Were looking at smaller and smaller particles in the atmosphere. So, weve had to make a shift in our calibration techniques. We have routine maintenance and then we have critical maintenance we do to the instrumentation just to make sure everythings the way its supposed to be. In the past we might look at an instrument every third flight. Now, with smaller particles and higher-resolution instruments, theres a need to calibrate and clean after every flight.
Don was chief scientist at RAF starting just after the Electra was acquired, and he worked there while it was being configured for its first research missions. He was also the principal investigator for the Air Mass Transformation Experiment (AMTEX) and was involved in many subsequent Electra programs.
|Don Lenschow. (Photo by Carlye Calvin.)|
Of course it was never designed for research. So, it was configured in a fairly luxury is not the word, but a relaxed sort of atmosphere. There were little tables and things and we left some of that stuff in. Most of it was torn out because we had to make room for instrument racks, but in the tail section we left some of that stuff in. So for long ferries it was a fairly comfortable airplaneas long as it wasnt bumpy, because the tail would rock around a lot more than the rest of the plane.
We ran the instruments most of the time when we were on these long ferries, just to see how things were working. Otherwise people would read materials, and then there was a lot of sightseeing, just looking out the window, observing all different things. The flight level is not as high as in a commercial jet aircraft, so you tend to be more involved in looking out the windows and seeing what is going on. . . .
The subsequent year [February 1975], we did the second stage of AMTEX, and the aircraft did very well. We were looking at what happens on the east edge of big continents. In the wintertime you get occasional extremely cold continental air coming off the coast where theres very warm water70 degrees [F] or something like that. You have tremendous potential for development of mesoscale circulations, and they can develop into fairly deep convective systemsrapid cyclogenesis where you get storms developing and this kind of thing. So, AMTEX was aimed at looking at the initial stages of that process. As the air comes off the coast, there is a tremendous amount of water vapor and heat flux that comes off the ocean. We measured how much was coming up into the atmosphere and a little bit on how it kind of reorganizes things in the atmosphere and causes development of systems. But we didnt get into the actual cyclogenesis aspect; this was more the transfer of energy from the ocean to the atmosphere.
Our typical pattern was to fly out north and west of Okinawa, up into the area where the cold air was coming off the coast, and fly low in the boundary layer at maybe 500 feet above the surface. We would go out at that level, and then we would ferry to a particular area on the basis of satellite photos and other weather information, and then fly a series of flight legs at various levels, from 100 feet on up to maybe a few thousand feet, to just above the boundary layer. We measured the fluxes at various levels so we could get the structure as the function of height. These were typically six- to seven-hour flights.
We got really good use out of the data set. It turned out to be a one-of-a-kind data set because we had all of these hours of measurements of turbulence and of fluxes in a fairly uniform, very convective boundary layer with minimal diurnal variation, well capped by a strong inversion at the top. So we had a well-contained experimental domainand, because of this big temperature contrast, lots and lots of turbulent activity, so the boundary layer was very well mixed. We used that data set to characterize the structure in ways that hadnt been done beforekind of a generic convective boundary layer, and that was very successful. It wasnt quite what the experiment was focused on, which was really more the role that air-sea transfer plays in the development of weather systems further downstream. Other people used it for that purpose, but what we were primarily focused on was characterizing the convective process in a convective boundary layer, which had well-characterized uniform conditions. So there were a whole series of papers that came from it. In fact I continued to work with that data set until just a couple of years ago, and could very well use it again.
Edited by David Hosansky,
Prepared for the Web by Carlye Calvin
Last revised: Tues May 28 17:08:40 MST 2001