Lockheed L-188 Electra

https://en.wikipedia.org/wiki/Lockheed_L-188_Electra

The Lockheed L-188 Electra is an American turboprop airliner built by Lockheed.
First flown in 1957, it was the first large turboprop airliner built in the
United States. Initial sales were good, but after two fatal crashes that led to
expensive modifications to fix a design defect, no more were ordered. With its
unique high power-to-weight ratio, huge propellers and very short wings
(resulting in the majority of the wingspan being enveloped in propwash), large
Fowler flaps which significantly increased effective wing area when extended,
and four-engined design, the airplane had airfield performance capabilities
unmatched by many jet transport aircraft even today—particularly on short
runways and high field elevations. Jet airliners soon supplanted turboprops for
many purposes, and many Electras were modified as freighters. Some Electras are
still being used in various roles into the 21st century. The airframe was also
used as the basis for the much more successful Lockheed P-3 Orion maritime
patrol aircraft.

The Model 188 Electra is a low-wing cantilever monoplane powered by four
wing-mounted Allison 501-D13 turboprops. It has a retractable tricycle landing
gear and a conventional tail. It has a cockpit crew of three and can carry 66 to
80 passengers in a mixed-class arrangement, although 98 could be carried in a
high-density layout. The first variant was the Model 188A, followed by the
longer-range 188C with room for 1,000 US gallons (3,800 L) more fuel and maximum
take-off weight 3,000 pounds (1,400 kg) higher.


Role
Turboprop airliner

National origin
United States

Manufacturer
Lockheed Corporation

First flight
December 6, 1957

Introduction
January 12, 1959 with Eastern Air Lines

Status
In limited use

Primary users
American Airlines
Eastern Air Lines
Braniff Airways
National Airlines

Produced
1957–61

Number built
170

Variants
Lockheed P-3 Orion

American Airlines was the launch customer. Eastern Air Lines, Braniff Airways
and Northwest Airlines followed. The Electra suffered a troubled start.
Passengers of early aircraft complained of noise in the cabin forward of the
wings, caused by propeller resonance. Lockheed redesigned the engine nacelles,
tilting the engines upwards three degrees. The changes were incorporated on the
production line by mid-1959 or as modification kits for the aircraft already
built, and resulted in improved performance and a better ride for passengers.

Three aircraft were lost in fatal accidents between February 1959 and March
1960. After the third crash, the FAA limited the Electra's speed until the cause
could be determined.

After an extensive investigation, two of the crashes (in September 1959 and
March 1960) were found to be caused by an engine mount problem. The mounts were
not strong enough to damp a phenomenon called "whirl mode flutter" (analogous to
the precession of a child's top as it slows down) that affected the outboard
engine nacelles. When the oscillation was transmitted to the wings and the
flutter frequency decreased to a point where it was resonant with the outer wing
panels (at the same frequency, or harmonically related ones), violent
up-and-down oscillation increased until the wings would tear off. The company
implemented an expensive modification program (the Lockheed Electra Achievement
Program or LEAP) in which the engine mounts and the wing structures supporting
the mounts were strengthened, and some of the wing skins were replaced with
thicker material. All Electras were modified at Lockheed's expense at the
factory, the modifications taking 20 days for each aircraft. The changes were
incorporated in later aircraft as they were built. However, the damage had been
done, and the public lost confidence in the type. This and the smaller jets that
were being introduced eventually relegated Electras to the smallest airlines.
Production ended in 1961 after 170 had been built. Losses to Lockheed have been
estimated as high as $57 million, not counting an additional $55 million in
lawsuits. Electras continued to carry passengers into the 1980s, but most now in
use are freighters.

In 1973, the Argentine Navy bought three Electras equipped with cargo doors.
These were used during the "Dirty War" to toss political prisoners into the Rio
de La Plata in the infamous death flights. The Electras were also used for
transport duties during the Falklands War in 1982.

Specifications (Model 188A)

General characteristics
Crew: Five (3 flight deck)
Capacity: 98 passengers
Payload: 33,800 lb (15331 kg)
Length: 104 ft 6 in (31.85 m)
Wingspan: 99 ft 0 in (30.18 m)
Height: 32 ft 10 in (10.00 m)
Wing area: 1,300 sq ft (120.8 m²)
Empty weight: 57,400 lb (26,036 kg)
Max. takeoff weight: 113,000 lb (51,256 kg)
Powerplant: 4 × Allison 501-D13 turboprop engines, 3,750 eshp (2,800 kW) each

Performance
Maximum speed: 390 knots (448 mph, 721 km/h) at 12,000 ft (3,660 m)
Cruise speed: 324 knots (373 mph, 600 km/h)
Range: 1,913 nmi (2,200 mi, 3,540 km) with maximum payload, 2,409 nmi, 2,770 mi,
4,455 km with 17,500 lb (7,938 kg) payload
Service ceiling: 32,000 ft (9,753 m)
Rate of climb: 1,970 ft/min (10 m/s)






*

On 20 Aug 2017 06:59:37 -0700, Miloch
wrote: Western Airlines was also another user of the Electra. They
replaced the DC-6B's as Western's major aircraft. When they introduced
the Electra they had two special flights out of Ontario, California
for city dignitaries. I knew the Western Airline agent at Ontario,
and he was able to get me on board for one of the flights. Great
aircraft, the take off run, really pushed you back in your seat !

https://en.wikipedia.org/wiki/Lockheed_L-188_Electra

The Lockheed L-188 Electra is an American turboprop airliner built by Lockheed.
First flown in 1957, it was the first large turboprop airliner built in the
United States. Initial sales were good, but after two fatal crashes that led to
expensive modifications to fix a design defect, no more were ordered. With its
unique high power-to-weight ratio, huge propellers and very short wings
(resulting in the majority of the wingspan being enveloped in propwash), large
Fowler flaps which significantly increased effective wing area when extended,
and four-engined design, the airplane had airfield performance capabilities
unmatched by many jet transport aircraft even today—particularly on short
runways and high field elevations. Jet airliners soon supplanted turboprops for
many purposes, and many Electras were modified as freighters. Some Electras are
still being used in various roles into the 21st century. The airframe was also
used as the basis for the much more successful Lockheed P-3 Orion maritime
patrol aircraft.

The Model 188 Electra is a low-wing cantilever monoplane powered by four
wing-mounted Allison 501-D13 turboprops. It has a retractable tricycle landing
gear and a conventional tail. It has a cockpit crew of three and can carry 66 to
80 passengers in a mixed-class arrangement, although 98 could be carried in a
high-density layout. The first variant was the Model 188A, followed by the
longer-range 188C with room for 1,000 US gallons (3,800 L) more fuel and maximum
take-off weight 3,000 pounds (1,400 kg) higher.


Role
Turboprop airliner

National origin
United States

Manufacturer
Lockheed Corporation

First flight
December 6, 1957

Introduction
January 12, 1959 with Eastern Air Lines

Status
In limited use

Primary users
American Airlines
Eastern Air Lines
Braniff Airways
National Airlines

Produced
1957–61

Number built
170

Variants
Lockheed P-3 Orion

American Airlines was the launch customer. Eastern Air Lines, Braniff Airways
and Northwest Airlines followed. The Electra suffered a troubled start.
Passengers of early aircraft complained of noise in the cabin forward of the
wings, caused by propeller resonance. Lockheed redesigned the engine nacelles,
tilting the engines upwards three degrees. The changes were incorporated on the
production line by mid-1959 or as modification kits for the aircraft already
built, and resulted in improved performance and a better ride for passengers.

Three aircraft were lost in fatal accidents between February 1959 and March
1960. After the third crash, the FAA limited the Electra's speed until the cause
could be determined.

After an extensive investigation, two of the crashes (in September 1959 and
March 1960) were found to be caused by an engine mount problem. The mounts were
not strong enough to damp a phenomenon called "whirl mode flutter" (analogous to
the precession of a child's top as it slows down) that affected the outboard
engine nacelles. When the oscillation was transmitted to the wings and the
flutter frequency decreased to a point where it was resonant with the outer wing
panels (at the same frequency, or harmonically related ones), violent
up-and-down oscillation increased until the wings would tear off. The company
implemented an expensive modification program (the Lockheed Electra Achievement
Program or LEAP) in which the engine mounts and the wing structures supporting
the mounts were strengthened, and some of the wing skins were replaced with
thicker material. All Electras were modified at Lockheed's expense at the
factory, the modifications taking 20 days for each aircraft. The changes were
incorporated in later aircraft as they were built. However, the damage had been
done, and the public lost confidence in the type. This and the smaller jets that
were being introduced eventually relegated Electras to the smallest airlines.
Production ended in 1961 after 170 had been built. Losses to Lockheed have been
estimated as high as $57 million, not counting an additional $55 million in
lawsuits. Electras continued to carry passengers into the 1980s, but most now in
use are freighters.

In 1973, the Argentine Navy bought three Electras equipped with cargo doors.
These were used during the "Dirty War" to toss political prisoners into the Rio
de La Plata in the infamous death flights. The Electras were also used for
transport duties during the Falklands War in 1982.

Specifications (Model 188A)

General characteristics
Crew: Five (3 flight deck)
Capacity: 98 passengers
Payload: 33,800 lb (15331 kg)
Length: 104 ft 6 in (31.85 m)
Wingspan: 99 ft 0 in (30.18 m)
Height: 32 ft 10 in (10.00 m)
Wing area: 1,300 sq ft (120.8 m²)
Empty weight: 57,400 lb (26,036 kg)
Max. takeoff weight: 113,000 lb (51,256 kg)
Powerplant: 4 × Allison 501-D13 turboprop engines, 3,750 eshp (2,800 kW) each

Performance
Maximum speed: 390 knots (448 mph, 721 km/h) at 12,000 ft (3,660 m)
Cruise speed: 324 knots (373 mph, 600 km/h)
Range: 1,913 nmi (2,200 mi, 3,540 km) with maximum payload, 2,409 nmi, 2,770 mi,
4,455 km with 17,500 lb (7,938 kg) payload
Service ceiling: 32,000 ft (9,753 m)
Rate of climb: 1,970 ft/min (10 m/s)






*

wrote in message ...

On 20 Aug 2017 06:59:37 -0700, Miloch wrote:
Western Airlines was also another user of the Electra. They replaced the
DC-6B's as Western's major aircraft. When they introduced the Electra
they had two special flights out of Ontario, California for city
dignitaries. I knew the Western Airline agent at Ontario, and he was able
to get me on board for one of the flights. Great aircraft, the take off
run, really pushed you back in your seat !

The article below is par for the course when it comes to most Sub-Saharan
airlines. The Lockheed L-188 Electra now carries cargo mostly, but in
darkest Africa, the natives are packed aboard SRO, and folklore is rich with
tales about, when a fuselage is full, jungle bunnies with only a few
shillings to spend will be allowed to climb into the baggage compartments,
meaning that on takeoff these 60-year-old airframes are carrying two to
three times the number of passengers they were designed for. "Many private
airlines operate out of Zaire, with relatively few controls over safety and
maintenance." Of course, most aren't FAA-certified. "There have been a
spate of plane crashes in the region recently." As long as all those
involved are from the Heart of Darkness, it rarely makes the news:
https://aviation-safety.net/database...?id=19951218-0
-------------------------------------------------------------------------
Mystery surrounds Angola plane crash victims

(c) 1995 Copyright Nando.net
(c) 1995 Reuter Information Service

KINSHASA (Dec 20, 1995 - 09:17 EST) - The identity of 139 people killed when
a Zairean charter flight crashed in northern Angola on Monday remained a
mystery two days after the world's worst air disaster of 1995.

An Angolan government official said on Wednesday the plane crashed in
Angola's Lunda Norte province near the Zairean border and may have been on
charter to Jonas Savimbi's opposition UNITA movement.

Zaire's transport minister, Alexis Thambwe Mwamba, said 139 of the 144
people on Monday's flight from Kinshasa had been killed. Doctors said four
of the survivors were in intensive care with serious burns.

"There were 139 people on board, plus five crew. There were only five
survivors," Thambwe Mwamba told Reuters on Tuesday.

A ministry official said most of the dead were Angolans but had no further
details. Thambwe Mwamba had no precise details on where the plane went down,
its destination or on the identity of the passengers.

Lunda Norte governor Moises Ndele told Angolan state radio the plane had
crashed in the UNITA-controlled Cuango area of the province.

"The plane could have been rented by UNITA coming from Zaire via Damba,
which is a region under UNITA's control in Uige province.

"The plane crashed around the Cuango area, an area under UNITA control," he
said, adding that aircraft from Zaire frequently landed at an airstrip close
to the town of Luzamba.

Another theory suggested a link with the diamond trade.

Many of the diamonds produced in Angola's remote Lunda Norte and Lunda Sul
regions are smuggled out via Zaire and large numbers of Zaireans regularly
travel to eastern Angola to dig for diamonds or buy them to sell.

For many years Zaire was accused of supporting Savimbi's UNITA rebels, who
controlled much of the diamond area but have since agreed a peace deal with
the government in Luanda.

Many private airlines operate out of Zaire, with relatively few controls
over safety and maintenance. In May 1994, Zaire's acting foreign minister
and a Tunisian presidential aide were among nine people killed in a crash on
the approach to Kinshasa's Ndjili airport.

A transport ministry official said the plane used for Monday's charter
flight was an Electra, based at Ndjili and owned by Trans Service Airlift, a
private company.

Officials could not say what caused the crash but Thambwe Mwamba said an
inquiry was under way. "I also have to speak to the owner of TSA, who is a
Belgian. I hope we should know more in the next few days," he said.

Hospital staff said five survivors were flown to Kinshasa on Tuesday and
four were in intensive care in Ngaliema clinic.

"They have been badly burned and their condition is serious. At this stage
they are unable to talk," a doctor said.

A fifth survivor, the co-pilot, had been taken away by his family. Five
corpses were also brought back from Angola.

Reference books suggest the largest Electra, a plane built by Lockheed,
entered service worldwide in 1959 with an intended capacity of 99 passengers
or 12 tonnes of cargo.

There have been a spate of plane crashes in the region recently. On December
3 a Cameroon Airlines Boeing 737 crashed as it came into land at Cameroon's
Douala port, killing 72 people.

In Nigeria's latest accident last month, a Nigeria Airways Boeing 737
crashed on landing at Kaduna airport in the north, killing nine people and
injuring 44.

Before Monday's crash, the worst air disaster of 1995 involved a Russian
Aeroflot Tu-154 which disappeared on December 7 with 97 people on board. The
wreckage was found on Monday inland from the Tatar Strait.