Lockheed L-188 Electra

Why the Electra mattered

The Lockheed L-188 Electra was the first large turboprop airliner built in the United States. It first flew on December 6, 1957, and entered airline service on January 12, 1959.

Lockheed built it for a specific customer. American Airlines wanted a four-engine, 75-passenger airliner for domestic routes, and ordered 35 on June 8, 1955. Eastern Air Lines followed with an order for 40 on September 27, 1955.

Eastern took the first delivery on October 8, 1958, after the aircraft received its Civil Aeronautics Administration type certificate on August 22, 1958. In all, 170 were built between 1957 and 1961.

How the Electra was designed

Four Allison 501-D13 turboprops drove large propellers, and their slipstream washed over most of the short, low wing. That gave the Electra strong takeoff performance for a heavy airliner and made it a good fit for shorter runways.

A typical crew was three: two pilots and a flight engineer. The full specification table for the aircraft is on this page, so this article covers the context behind the numbers instead.

On paper the Electra was fast. The 188A’s top speed is quoted at 389 knots (448 mph) at 12,000 ft, with a normal cruise around 324 knots (373 mph). That put it close to early jets on medium routes while burning less fuel.

The panel lists two speeds because the quoted figures measure different things. Maximum speed is a limit at a given altitude, while cruise speed is what airlines actually flew day to day.

The aircraft was also rated for around 98 passengers in a high-density layout, or about 33,700 lb (15,300 kg) of payload when carrying freight. That freight flexibility is what kept it alive later.

Whirl-mode flutter: the crashes that nearly ended it

Braniff Flight 542 broke up near Buffalo, Texas, on September 29, 1959, killing all 34 people aboard. Northwest Flight 710 came apart over Perry County, Indiana, on March 17, 1960, killing all 63.

Investigators traced both to whirl-mode flutter. A weakened engine mount let a propeller and its gearbox wobble, and the vibration fed into the wing until it reached a resonant frequency and the wing failed.

Lockheed’s fix was the Lockheed Electra Achievement Program. The company strengthened the engine mounts and supporting wing structure, replaced some wing skins with thicker material, and modified every Electra at its own expense. The work took about 20 days per aircraft.

The reputational damage was already done. Airlines had jets on order, and the Electra never sold in the numbers Lockheed had planned.

From airliner to P-3 Orion

The US Navy asked for a new maritime patrol aircraft in 1957, and Lockheed proposed a development of the Electra. The first prototype was converted from an existing L-188 airframe.

The result was the P-3 Orion, which has served for more than 50 years. Few airliners have a military descendant with such a long front-line career.

Cargo, freight and firefighting Electras

From 1968, a Lockheed subsidiary converted 40 Electras to freighters, adding large cargo doors and a reinforced floor. Civilian contractors also flew Electras on the US military’s Logair and Quicktrans cargo networks.

Passenger service faded first. KLM ended its Electra flights in January 1969, and Varig retired its Rio de Janeiro to Sao Paulo shuttle Electras in 1992.

Some survivors were rebuilt as air tankers. Air Spray and Buffalo Airways in Canada have flown Electras on freight and firefighting work into recent years.

One later incident shows how robust the airframe is. On June 8, 1983, a propeller separated from a Reeve Aleutian Electra and tore a hole in the fuselage over the Pacific. The crew landed at Anchorage and all 15 people aboard survived.

Frequently Asked Questions

Are there any Lockheed Electra still flying?

Yes, a small number. Air Spray and Buffalo Airways in Canada have operated Electras as freighters and air tankers, though numbers keep shrinking as the airframes age. Passenger flights on the type have ended.

How much did an Electra cost?

We have not found a reliable per-aircraft price for the L-188, so we do not quote one. Lockheed’s own losses from the grounding and modification program were estimated as high as $57 million, plus lawsuits.

Why did the Lockheed Electra crash?

Two early crashes in 1959 and 1960 were caused by whirl-mode flutter, a wing vibration triggered by a weak engine mount. Lockheed strengthened the structure on every aircraft, and the fixed Electra went on to build a sound safety record.

Has Amelia Earhart’s Electra been found?

No. Earhart flew a different aircraft, the twin-engine Lockheed Model 10 Electra, and it has never been found. The L-188 is a later four-engine turboprop and is unrelated.

What engines does the L-188 Electra use?

Four Allison 501-D13 turboprops, the engine that later evolved into the T56 used on the P-3 Orion and C-130.