4 Incredibly Over-Engineered Aircraft

by Stephen Mraz
Feb 17, 2016

Why is it that some airplanes seem to fly well past what anyone could’ve hoped for in terms of an operational life? Is it overdesign or good design or both? Healthy safety margins? Designers with an eye toward engineering rather than planned obsolescence? Or maybe it’s just dumb luck. But as Obi-Wan Kenobi said, “There is no such thing as luck.” And, to throw in another “literary” quote, this one from Branch Rickey, “Luck is the residue of design.”

Either way, here are some planes that seem to have out-flown other planes of their era.

The Douglas DC-3 has to be the king of over-engineered aircraft. The twin piston-engined monoplane was first developed and flew in 1936 as an airliner that could hold 14 sleeper beds. As an airliner, it brought about true coast-to-coast flying. Granted, it could be a 17.5-hr. flight with three fuel stops. But until then, it took two days of short hops plus an overnight train trip. The plane cost about $80,000 when built, which means they would run $1.4 million today.

But the plane really took off in World War II (pun intended). It was renamed the C-47 Skytrain (and called the Dakota in the RAF) and over 16,000 were built. Even the Russians built versions. It was used for troop and cargo transport, dropped paratroopers into battle (more than 50,000 in the first days after D-Day), and towed gliders to altitude, among other missions.

It’s estimated that about 400 DC-3s and converted C-47s are still flying, 70 years after production stopped. It could be the first airliner to fly for over a century. Pilots appreciate its good handling characteristics, rugged landing gear, and ability to land and take off from short fields. They are also said to be easy to maintain, though parts are probably hard to come by.

Boeing’s B-52 Stratofortress long served as the U.S. Air Force’s main strategic bomber after it entered service in 1955, and is still a key element in the U.S. arsenal. It is also the U.S. aircraft capable of carrying the widest assortment of weapons including gravity bombs, cluster bombs, precision-guided missiles, and joint direct-attack munitions. It can carry up to 70,000 lb. of ordnance.

Nearly 750 B-52s were built through 1962, including models A though H, and then production stopped. Only the H version is still flying. But upgrades and good maintenance should keep them flying beyond 2040, according to some engineering analyses.

The bomber is powered by eight Pratt & Whitney engines, each putting out 17,000 lb. of thrust. Top speed is 650 mph and it has a maximum take-off weight of 488,000 lb. It has a range of 10,145 miles, but it can fly indefinitely with aerial refueling.

The Lockheed C-130 Hercules also entered service in 1955, but as a military transport plane capable of using unprepared runways for landings and takeoffs. It started life as a cargo and troop/medivac vehicle, but has been used as a platform for a gunship (AC-130), assault aircraft, firefighter, refueling tanker, search and rescue vehicle over land and sea, weather recon, and scientific support vehicle. Over 2,500 have been built in over 40 variations, and it is still in production. In fact, it holds the record for the longest continuous production run of any military aircraft. The Hercules is flown by the militaries of more than 60 countries.

The McDonnell Douglas F-4 Phantom was developed as a two-seat, twin-engine supersonic fighter/bomber for the Navy and entered service in 1960. It was quickly adopted by the Marines and Air Force. Right out of the box, the Phantom began setting speed and altitude records, racking up 15 before it was five years old. It could fly Mach 2.5 and climb as high as 98,000 ft. It could also carry up to 18,000 lb. of armaments, including a wide assortment of missiles and bombs. Soon after it was initially deployed, the Navy had rotary cannon installed for air-to-air combat and strafing.

The F-4 was a mainstay of the U.S. military through the Vietnam War and wasn’t replaced by aircraft such as the F-15 Eagle, F-16 Falcon, and F-14 Tomcat until the 1980s. Even then, it still served a role in the Marines and Air Force, as well as the Reserves. It also flew in the Gulf War in 1991. It was finally retired in 1996. During its career, it was the only aircraft flown by both the Navy Blue Angels and the Air Force Thunderbirds.

Discuss this Blog Entry 15

on Feb 19, 2016

I suspect those planes were initially design without the "benefit" of FEA so that their designers had to include healthy margins of safety. One comment on the DC-3: None ever crashed because of structural failure. And just to be a contrarian, the Internet says John Milton first make the quote regarding luck. All the same, I loved the article.

on May 27, 2016

Air Force and Navy requirements are quite different from each other. This simple fact still hasn't been accepted by those who hold the purse strings.

on Feb 24, 2016

Spent the 80's in the USAF, got to work on both the F-4 and B-52. Flew in the C-130. All were great aircraft.

on Feb 24, 2016

DeHavilland Canada Dash 8 series 100,200 and 300 aircraft are known to have 4 lifetimes on their structures and that with an average recorded flight cycle time of 52 to 58 minutes...fatigue provoking circumstances.
It's all to do with metal to metal adhesive bonding...Fleet in Fort Erie have been doing this for DeHavilland for decades. The aircraft are not over designed but every load path is closed in traditional DeH aircraft design so that has probably a lot to do with longevity.

on Feb 24, 2016

ScotCan :
As a proponent of riv-bonding, your comment interests me.
I am a vehicle design engineer and have had success with riv-bonded structure, however, the analysis of this class of structure is difficult, and in my experience its tough to exploit the advantages without extensive tests.
I'd like to talk further with you on this subject if you are willing, but I'm not sure how to do that without exposing my email/phone no. on a public forum...

on Feb 24, 2016

There is a large difference in the aircraft metal to metal adhesive bonding process and what is described as riv-bonding. The panels are phosphoric acid anodised, elaborately checked for conformance, then primed with a certified primer and again inspected. The adhesive is a certified component with a strictly controlled shelf life and the mating parts are installed and vacuum bagged prior to putting them into an autoclave. The autoclave temperature and pressure are maintained within a narrow band of acceptance for the 90 minute autoclave cycle and the processing chart becomes part of the paperwork traveling with the assembly. The panel is inspected completely for any voids between the mating parts and a map of the number and size of the voids is recorded. There is a defined allowance for the size of voids and their spacing and any deviation is recorded as non-conformance for disposition by Liaison Engineering which for subcontracted work requires endorsement by the Customer. Each phase of the process is inspected and all non-conformance reported sometimes as snags (local buy off) sometimes requiring Customer approval. This description relates to pressurised fuselage panels but applies also to wing panels and control surfaces. Test pieces which accompany the panels through the autoclave process are tested for peel strength and the records accompany the panels as part of the paperwork certifying the integrity of the assembly.
Perhaps as the author indicates this appears to be an over engineered product but any Liaison Engineer will tell you real life shop floor conditions justify such an elaborate range of procedures because of tolerance build ups, material variances (such as stress relief of shot peened parts) and so on.
Apologies for being so long winded

on Feb 24, 2016

A very nice and Informative Article.

on Feb 24, 2016

Don't know how much is available free, but recently Aviation Week and Space Technology scanned in ALL of their issues for the 100th anniversary of the magazine. This is a tremendous resource that documents the history of aviation and space the last 100 years. They were the mag. that scooped the Yeager's supersonic flight, though it was considered top secret at the time (the wags call the magazine "Aviation Leak and Spy Technology" because of scoops like that).

on Feb 24, 2016

More important, I think, than computer aided design tools, the folks who designed these machines were masters of 2D analog design.

Modern design tools are great, but things get lost when designers don't have to know and understand the 'details'. If you dropped a stack of airfoil tables, a ream of paper, some #2 pencils and a slide rule in front of most modern designers and engineers they'd sue for poor working conditions. Modern education resembles vendor training more and more every semester. A beautifully designed BOM, a stunningly well organized content library and a complex simulation will get you the grade, but your design won't fly (ha).

Regardless, I take issue with the title of the article. Over-engineered is not a positive thing. It doesn't mean the end result will work better or last longer. It means poor design. It means poor engineering. It means that an inability to meet design requirements was 'overcome' by piling on excess resources and hoping the simulation doesn't fall down when the design is presented to the client.

Good design and engineering means aircraft from the 1950's are still flying around and aircraft from the 1980's perform best when parked. Over-engineering is the F-35. Looks great, eats pilots.

on Feb 24, 2016

All good points and as much as I like 3DCAD and use it a lot some of the convoluted results make me wonder about shared algorithms and the like which keep nagging away in the background. Fortunately I work with a prototype builder with extensive tribal knowledge and he fulfills the intent of the design adjusting the "pretty pictures" as he calls them. In earlier times you could walk around the drawing office and quickly scan what was going on and by knowing the strengths and weaknesses of the designer keep things from going wrong. Sadly, not today...all CAD work looks exactly the same and there is no way to tell whether a design is good bad or indifferent.

on Feb 24, 2016

Not to detract from the awesome F-4 Phantom, but the Boeing Vertol CH47 "Chinook" helicopter should be #4. It entered service in 1962 and is still on active duty!

on Feb 24, 2016

If the list ever expands, I would nominate the PBY, "Flying Boat" which, last I heard, is still flying! Great article!

on Mar 2, 2016

I will take both nominations, the PBY and Chinook, into consideration for Round Two of Incredibly Over Engineered Aircraft. Any other nominations?

on Feb 24, 2016

The reason many great military aircraft are retired is because of political interests. Engineering "problems" can be invented to help justify retirement. Numbers can be fudged.

I think the political story that keeps the B52 air born is just as interesting as the Engineering story.

Thankfully the A-10 Thunderbolt is still there for our Troops.

on Jul 5, 2016

"Thankfully the A-10 Thunderbolt is still there for our Troops."

Speaking of aircraft kept afloat because of political interests rather than empirical or logical analysis...

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