As we taxied in at Aguadilla Airport in Puerto Rico I noticed a familiar silhouette parked near the Lufthansa hanger. There is no mistaking the distinctive triple fin of a Lockheed Constellation.

A bit of research tells me this aircraft is Constellation 4825 City of Miami. It has a pretty interesting history. During the 1960s it was operated by Air America (CIA). From 1969 through the late 1980s it was owned by a variety of oil companies and freight outfits. In 1988 it was sold to Aerolineas Mundo (AMSA). While parked at Borinquen (Aguadilla) in 1992 it was damaged when a DC-4 taxied into it. It has sat there ever since. What were the odds of a DC-4 running into a Constellation in 1992?

I’m always fascinated by the last days of an old technology and the first days of a new one. This period represents the apex of piston engine technology before the transition to jets in the late 1950s.

So let’s turn the clock back to the 1950s, a time when people lived in daily fear of nuclear annihilation. OK, so it wasn’t really much different than today, but the planes were still glamorous.

Boeing Stratocruiser

The odd looking Boeing 377 was larger and more luxurious than the competition of the day.

The Stratocruiser was powered by four Pratt & Whitney R-4360 “Wasp Major” engines. These saw extensive military use in aircraft like the Convair B-36 and the KC-97 tanker. The Stratocruiser was the only airliner to ever use this engine, for reasons to be discussed later.

OK gearheads, let’s look at this monster. You think your 454 Chevy or Chrysler Hemi is impressive? This thing would use your 454 as a starter.

The R-4360 had 28 cylinders in four rows of seven, displacing a massive 4,362 cubic inches. It’s a 426 Hemi times ten and then some. It most closely resembled a corncob, and was sometimes referred to as such.

Cutaway view of an R-4360

The supercharged version in the Stratocruiser put out a whopping 3,500 horsepower. I’d like to have one in my car, but it weighed as much as a car (3,870 pounds).

With four of these engines a Stratocruiser had 112 cylinders, 224 valves and 224 spark-plugs churning a combined 14,000 horsepower, while trying to beat themselves to death 2000 times per minute. I can imagine a flight engineer on a Boeing 377 was a busy man indeed (they were all men in those days).

Probably looked about like this guy.

If you screwed up starting one of these things, you could foul all 56 of those spark plugs and the mechanics would hate you. Not to mention everyone else, since I’m sure it took a while to change 56 spark plugs.

All that horsepower came with a hefty price tag. These engines were very maintenance intensive. Not so much of a problem for the military, but not a good thing if you’re running an airline. They were also prone to in flight fires, never a good thing and especially bad in an airliner halfway between Hawaii and the West Coast.

“Sleeper” berth on a 377.

Largely due to problems with the engines, the Stratocruiser was plagued by reliability issues. A mere 56 were built and 13 of those were lost (yikes!). That has to be one of the worst loss rates in the history of commercial aviation.

In addition, they were expensive to operate and not really profitable for the airlines. If not for the success of the 707, I can imagine an alternate history where Boeing quit the airliner business altogether after the Stratocruiser.

I’ve never seen one of these but I can recall seeing similar looking KC-97 tankers back in the early 1970s.

Douglas DC-6/DC-7

DC-7 in American Airlines livery.

The DC-6 was arguably the most successful design of the era. Basically it was a larger version of the DC-4 (military C-54) with bigger engines and a pressurized cabin. They came to be very popular with the airlines due to their reliability, sturdy build and economical operation. There are still a handful of DC-6s flying cargo and fighting fires.

The larger and faster DC-7 was built to fly coast-to-coast in 8 hours, the maximum flight time allowed for a single crew by the Civil Aeronautics Board. That may seem like a long time today, but crossing the country a few years earlier in a DC-3 took roughly twice that much time and required multiple stops along the way.

The DC-7 was slightly larger than the DC-6 and was powered by four Wright R-3350 “Duplex Cyclone” engines. The more powerful engines gave the DC-7 about a 50 mph speed advantage in cruise over the DC-6.

DC-7 cockpit. Not to be confused with a Russian submarine.

The R-3350 was arguably the apex of piston engine design, at least in the airline world. I suppose a case could be made for the British Napier Sabre engine, but it was only used to power fighters.

Smaller than the giant Wasp Major engines on the Stratocruiser, the Wright engines had 18 cylinders arranged in two rows of 9. Displacement was a “mere” 3,347 cubic inches. That’s 54.8 liters if you like.

The Dupex-Cyclone had a two-speed supercharger which enabled it to perform in the thin air at higher altitudes. It worked sort of like the transmission in a car. At a certain altitude (somewhere around 15,000 feet I believe) the supercharger would be switched to “high”. This allowed the DC-7 to cruise as high as 28,000 feet.

This engine had one other neat trick to eek out every last bit of horsepower. It was called turbo-compounding. The exhaust gases spun a “power recovery turbine” which was then coupled back to the engine. The R-3350 had three of these, which gave some versions as much as 3,400 horsepower.

Cutaway of an R-3350. The red arrow points to one of the Power Recovery Turbines.

Never as successful as its predecessor, many DC-7s were retired early when the first jets arrived in 1958. The Wright engines, while more powerful, were never as reliable as the more straightforward engines that powered the DC-6. Still, a respectable 338 were built. A handful are still flying today as firefighters or cargo haulers.

Lockheed Constellation/Super Constellation

I’d say any list of “best looking aircraft” has to feature the Lockheed Constellation somewhere in the top ten.

The different military and civilian versions of the “Connie” are too numerous to list here. I’ll stick with the three main airline versions.

L-049 Constellation

A “regular” Constellation in BOAC livery. I’m old enough to remember BOAC.

This was the original airliner version. Designed by the legendary Clarence “Kelly” Johnson, it was roughly equivalent to the DC-6 in market niche and capability. The Lockheed was more advanced than the Douglas, featuring hydraulically boosted flight controls among other advances. Pretty heady stuff for 1943. Even the DC-8 jet didn’t have boosted flight controls. Hence the saying “Boeing builds airliners, Douglas builds character”.

It’s been said that the ultimate airliner would be designed by Lockheed, built by Boeing and marketed by Douglas.

The Constellation featured a beautifully tapered fuselage, which gave it a sleek, graceful appearance. In fact, no two bulkheads were the same size on a Constellation, which made it expensive to build.

The DC-6, while a good looking aircraft in its own right, looked rather stodgy next to the Connie.

The Constellation had a relatively cramped cockpit compared to its Douglas rival.

The original Constellation used an early version of the Wright R-3350 engine, minus the turbo-compounding. These put out a respectable 2,200 horsepower each.

Having found a Constellation Flight Engineer’s Handbook, this is what it took just to start the engines:

Compare this to starting the 767. I turn a switch to “start”. When the engine gets to a certain RPM I turn the fuel switch to “run”. The rest takes care of itself.

A jet engine has one lever to control it. The newer jet engines even have a digital fuel control that prevents idiot-boy here from hurting it.

A large recip has: throttle, prop, mixture, carburetor heat, cowl flaps plus a few others that all have to be operated correctly or bad things happen to the engine. A flight engineer on one of these had to keep a close eye on the cylinder head temperatures during takeoff and climb out lest the engine cook itself.

Constellation before-takeoff checklist, back when airline pilots were all square-jawed white guys.

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Star Trek creator Gene Roddenberry flew Constellations for Pan Am. After surviving a horrific crash in 1947, he quit a year later to pursue his dream of writing.

L-1049 Super Constellation

A Super Constellation in TWA colors. This one does not have the distinctive weather radar in the nose.

The Super Constellation was stretched 18 feet over the original and featured several improvements. Most notably it received the turbo-compound version of the R-3350 engine. It was faster, carried more passengers and had significantly more range than its predecessor.

Veteran TWA pilot Bob Buck, in his autobiographical North Star Over My Shoulder, stated that the two-stage superchargers on these were unreliable. They were frequently stuck cruising at the lower altitudes when one of them wouldn’t shift into “high gear”.

R-3350 engine on Super Constellation.

A total of 259 civilian L-1049s were built in various versions. I’ve always liked the looks of the L-1049G “Super G” with the tip tanks on the wing.

L-1049G “Super G” with tip tanks and weather radar.

The military operated the type as the C-121 or as the EC-121, which was the first AWACS. I flew with a Captain a few years back who had logged time in the EC-121. She also had the distinction of being one of the first female naval aviators to be carrier qualified.

Navy EC-121 with distinctive upper and lower radomes.

Sally flies to New York! On a TWA Super Constellation! This video just begs for the Mystery Science Theater 3000 treatment.

I’m told that I flew on one of these (as well as a DC-3) when I was very young but I don’t really remember it. This would have been in the early-mid 1960s.

L-1649 Starliner

TWA Starliner.

The idea of calling something with propellers a “Starliner” seems a bit optimistic but hey, it was the 1950s. We were all going to have jet packs and be living in moon colonies in a few years. “Star” and “Astro” were common names back then.

The Starliner was built to one-up the DC-7 and featured a completely redesigned wing that was much longer than the original with less “chord” (front to back). Only 44 of these were built, so I doubt Lockheed made any money off the redesign.

The main advantage of the Starliner was that it could fly nonstop from the West Coast to Europe. I don’t think I’d have wanted to sit in one for that long. Paris to New York took over 14 hours in a DC-7 or a Connie. California to Europe would have taken a good bit longer.

Interior of a restored Lufthansa Starliner.

We tend to think of this as a “golden age” of air travel. I think this may come from having seen too many old movies. The reality of it was plowing through the weather at 15,000 feet with a bunch of people getting airsick all while being subjected to the noise and vibration of four massive piston engines.

While these were beautiful aircraft, their days were numbered. The arrival of the 707 and DC-8 in the late 1950s sealed their fate. The speed of a jet made it twice as productive. A DC-8 could cross the country twice in the time it took a DC-7 to do it once, all while carrying a larger passenger load.

In addition the jets were much more comfortable.

I noticed this a few years ago when I took a ride on a B-17 (diary to come, don’t worry). After about 30 minutes of wallowing through the sky, I found myself actually getting queasy. Something I haven’t felt since my first few jet rides in the Air Force. Those old planes had a different motion to them than a swept-wing jet, something I wasn’t used to.

What really sold the airlines on jets, however, was the reliability.

In 33 years and over 7000 hours of jet time, I have never had to shut an engine down in flight. Pretty amazing when you consider that a B-52 gave you eight chances to have an engine failure on any given flight.

Back in the piston era, engine failures were a commonplace event. The Constellation was sometimes called “The world’s best three-engine airliner”, averaging 2-3 engine failures per plane per year. A recent article in Air & Space describes how QANTAS had a plane dedicated to just ferrying spare engines around their system.

Compared to something like an R-3350, a jet engine is a marvel of simplicity. As a bonus, the jet burns cheap kerosene instead of high-octane gasoline.

It was arguably the 707 that made flying affordable for the average person. The rest, as they say, is history.