Tag Archives: Heavy Lift Helicopter

21 September 1961

Aviation, , , , , , , , , , , , , ,
Vertol YCH-1B-BV 59-4983 hovers in ground effect. (Boeing Vertol)

21 September 1961: Boeing Vertol YCH-1B-BV, serial number 59-4983, a twin-turboshaft, tandem-rotor heavy lift helicopter, flown by test pilot Leonard Joseph (“Len”) LaVassar, made its first flight at Morton Grove, Pennsylvania. This aircraft was the number two prototype. (The first aircraft, 52-4982, had been damaged 12 July 1961 when the rotors went out of phase during ground testing. It was repaired but never flew.) In 1962, the YCH-1B was was redesignated YCH-47A.

The YCH-1B fuselage was 51 feet, 0 inches (15.545 meters) long and had a maximum width of 12 feet, 5 inches (3.785 meters). The helicopter’s overall length, with rotors turning, was 98 feet, 3.25 inches (29.953 meters), and its maximum height (to the tip of the uppermost blade) was 18 feet, 6.6 inches (5.654 meters). Empty weight of the production CH-47A is approximately 25,500 pounds.

The counter-rotating fully-articulated three-bladed rotors each had a diameter of 59 feet, 1.25 inches (18.015 meters). The forward rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) The rear rotor turns the opposite direction. They rotate at 215 r.p.m.

Boeing Vertol YCH-1B-BV 59-04983

The prototypes were powered by two Lycoming LTC4B-3 (T55-L-5) turboshaft engines. These were free-turbine engines using a 7-stage axial-flow, 1-stage centrifugal-flow compressor section with a single-stage high-pressure turbine and two-stage low-pressure power turbine. The T55-L-5 was rated at 1,870 shaft horsepower at 14,430 r.p.m. N2. It was 3 feet, 8.1 inches (1.120 meters) long and weighed 560 pounds (254 kilograms).

The helicopter had a maximum speed of 153 knots (176 miles per hour/283 kilometers per hour) at Sea Level. Its hover ceiling, out of ground effect (HOGE), was 11,650 feet (3,551 meters), and in ground effect (HIGE), 14,500 feet (4,420 meters). The helicopter’s service ceiling was 18,600 feet (5,669 meters).

The Chinook prototypes were painted white and orange. This is the third YCH-1B, 59-4984. (Boeing Vertol)

The Chinook remains in production as the CH-47F Block II and MH-47G, and is used by the military services of several nations.

Boeing CH-47F Chinook. (Boeing)

© 2018, Bryan R. Swopes

6 August 1969

Aviation, , , , , , , , , , , , ,
One of the two Mil Design Bureau V-12 heavy lift helicopter prototypes, 1971. (Groningen Airport-Eelde)

6 August 1969: The largest helicopter ever built, the four-engine, transverse tandem rotor Mil V-12, registration CCCP-21142, lifted a payload of 88,636 pounds (44,205 kilograms) to an altitude of 7,400 feet (2,255 meters). This weight record has never been broken by any helicopter.

FAI Record File Num #9916 [Direct Link]
Status: ratified – current record
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1 (Helicopters)
Category: General
Group: 2 : turbine
Type of record: Altitude with 35 000 kg payload
Performance: 2 255 m
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV, V.P. BARTCHENKOV, S.G. RIBALKO, A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

FAI Record File Num #9917 [Direct Link]
Status: ratified – current record
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1 (Helicopters)
Category: General
Group: 2 : turbine
Type of record: Altitude with 40 000 kg payload
Performance: 2 255 m
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV, V.P. BARTCHENKOV, S.G. RIBALKO, A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

FAI Record File Num #9937 [Direct Link]
Status: ratified – superseded since approved
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1e (Helicopters: take off weight 3000 to 4500 kg)
Category: General
Group: 2 : turbine
Type of record: Greatest mass carried to height of 2 000 m
Performance: 40 204.5 kg
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV,V.P. BARTCHENKO,S.G. RIBALKO,A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

This was the first of two prototypes built by the Mil Design Bureau. (Both had the same registration number: 21142.) It was intended to transport intercontinental ballistic missiles and load them directly into underground silos where there were no existing roads. The V-12 used two main rotor, transmission and twin engine systems from the single rotor Mil-6 helicopter. With counter-rotating main rotors, the torque created by each rotor system is cancelled out, eliminating the need for a tail, or anti-torque, rotor. This makes the total power produced available for lift. Each rotor had a diameter of 114 feet, 10 inches (35 meters). The four Soloviev D-25VF turboshaft engines combined to produce 26,000 horsepower. The aircraft was operated by a six-man crew. It’s maximum takeoff weight was 231,500 pounds (105,000 kilograms). It had a range of 310 miles (500 kilometers). Maximum speed of the V-12 was 140 knots (260 kilometers per hour) and the service ceiling was 11,500 feet (3,500 meters).

The helicopter was not put into series production. The record-setting first prototype is at the Mikhail Leontyevich Mil helicopter factory at Panki-Tomilino, near Moscow.

World Record Mil Mi-12 at Tomolino.
World Record holding Mil Mi-12 at Tomolino. (Yuriy Lapitskyi)

© 2015, Bryan R. Swopes