Daily Archives: March 12, 2017

12 March 2009

Cougar Helicopters Inc. Sikorsky S-92A C-GZCH (Transport Canada)

Cougar Helicopters, Inc., Flight 91 (Cougar 91), a Sikorsky S-92A helicopter, departed St. John’s International Airport (CYYT), Newfoundland, enroute to the Hibernia oil platform (the largest offshore oil platform) located 315 kilometers (196 miles) to the southeast in the Jeanne d’Arc Basin of the Grand Banks. The helicopter departed at 9:17 a.m. and climbed to its enroute cruise altitude of 9,000 feet (2,743 meters), leveling off at 9:32 a.m.

The aircraft was under the command of Captain Matthew William Davis, with First Officer Timothy Ross Lanouette. There were sixteen passengers. All on board were wearing full immersion suits.

Captain Davis had 5,997 hours of flight experience accumulated over 20 years as a professional helicopter pilot. He held a Canadian Airline Transport Pilot License with a Rotorcraft rating and was type-rated in the S-92A. He had 1,067 hours in type.

First Officer Lanouette had flown a total of 2,854 hours during 23 years with the Canadian Forces, and the 11 months he had worked for Cougar Helicopters. He also held a Canadian Airline Transport License with Rotorcraft rating. He was type-rated in the S-92A, and had 97 hours in type.

The Hibernia oil drilling and production platform, located at N. 46° 45′ 1.57″, W. 48° 46.58.54″, in 80 meters (262 feet) depth of water.

At 9:45:05, the crew received a series of indications of falling oil pressure in the transmission (also referred to as the main gear box, or MGB). Within 1 second, the amber CAUTION light was replaced by a red WARNING light and and audible “GEARBOX PRESSURE. . . GEARBOX PRESSURE. . .” warning. Within 20 seconds, the transmission oil pressure dropped from the normal range of 45–70 pounds per square inch (310.3–482.6 kilopascals) to less than 5 p.s.i. (34.5 kPa) This constituted an in-flight emergency which required that the crew land or ditch the helicopter immediately.

For the helicopter crew, ditching at sea must always be considered a life-and-death situation. At the time of the emergency, the surface weather along the route of flight was estimated as wind from the south-southeast at 22 knots (11.3 meters per second) and waves of 2.5 meters (8.2 feet) with a period of 7 seconds. (Sea State 4–5.)The water temperature was 0 °C (32 °F.). There were significant questions as to the survival chances of those on board Cougar 91.

Instead of proceeding with ditching, though, at 9:45:27, Captain Davis called Gander Area Control Center and declared an emergency:

“Gander Center, Cougar 91, mayday. Sir, we have a main gearbox oil pressure problem, request immediate clearance back to takeoff.”

The request was approved by air traffic control and Cougar 91 turned back toward St. John’s, approximately 54 nautical miles (62 miles/100 kilometers) away. Captain Davis began a descent from 9,000 feet (2,743 meters) at 9:45:31. The helicopter’s turn toward St. John’s was completed at 9:45:47.

At 9:45:58, Captain Davis told First Officer Lanouette that he was initiating a descent to the water and had Lanouette begin the emergency procedures check list.

Cockpit of a Sikorsky S-92A during a night flight over Riyadh, Saudi Arabia, at night. (Ahmed Hader via Wikipedia)

A few minutes later, Captain Davis called Gander ACC, “I’m going to the nearest terra firma I can get. Whatever I see first, if it’s Cape Spear or a parking lot. We’ve lost all gearbox pressure at this time.”

Finishing the emergency check list, First Officer Lanouette informed Captain Davis that they were in a LAND IMMEDIATELY condition. Davis replied that he was going to level off at 1,000 feet (305 meters). At 9:51:50 the pilot increased collective pitch to stop the descent. Engine torque increased and Cougar 91 leveled off at 800 feet (244 meters).

The flight crew suspected that the low oil pressure warnings were actually a sensor problem. Their previous training had suggested that any imminent problem with the transmission would be preceded by noises and vibrations, which they had not experienced. Also, because the oil temperature indication had not increased, they suspected that the transmission had not actually lost oil at all.

At 9:55:15, power to the helicopter’s flight recorder was cut off, indicating that something had occurred. There is every indication of a tail rotor drive failure. The helicopter’s main rotor r.p.m. increased from 103% Nr to 107% Nr. Ten seconds later, 9:55:25, the helicopter yawed to the right. The pilots lowered the collective, and moved the cyclic left and added left anti-torque pedal. At 9:55:36, the first officer called Gander, saying that they were ditching. At 9:55:37, Cougar 91 rolled right and the rate of right yaw increased to nearly 4° per second. At 9:55:44, the yaw rate increased to 20° per second.

At 9:55:47, both engines were shut down.

Descending through 600 feet (183 meters), the helicopter’s airspeed was 90 knots (167 kilometers per hour). Rotor r.p.m fluctuated between 105% and 95% as the pilots raised and lowered the collective. The S-92 appeared to be in a stable autorotation descending through 425 feet (130 meters) at 75 knots (139 kilometers per hour) with 98% Nr. It then rolled to the right, reaching a bank  angle of 57°. The main rotor accelerated back to 105%. Passing through 400 feet (122 meters) the collective was raised and the main rotor r.p.m. began to droop. The helicopter was traveling downwind at this time, with an estimated 32 knot (60 kilometers per hour) tailwind. The aircraft went through a series of extreme pitch, roll and yaw changes as the flight crew fought for control.

At 09:55:54, the crew began an autorotative flare at 220 feet (67 meters). The Sikorsky S-92A descended through 90 feet (27 meters) with a rate of descent of at least 2,300 feet per minute (11.7 meters per second), possibly much greater, and an airspeed of 66 knots (122 kilometers per hour). The main rotor was decelerating through 81% Nr. The helicopter was in a 16° nose-up attitude with a 9° left bank.

Cougar 91 hit the water at 9:56 a.m. The force of the impact was so great that the fuselage structure failed. The forward section, including the cockpit, broke off, as did the tail boom. The cabin section rolled over to the left and the aircraft sank immediately. The location was N. 47° 26′ 4.17″, W. 51° 56′ 42.53″.

Of the 18 persons on board Cougar 91, only one passenger—who had been seated on the right side of the passenger cabin, just forward of center, Seat 3D—survived. All others were found still strapped in their seats. They had received major lower limb fractures, spinal injuries, etc., and drowned. The survivor was rescued by Cougar Rescue 61, a company S-92A helicopter specially configured for search and rescue operations. He had been in the freezing water for approximately 1 hour, 20 minutes.

Wreckage of Cougar 91 was recovered from the sea floor at a depth of approximately 550 feet (168 meters) and returned to St. John’s for analysis.

Recovered wreckage of Cougar Helicopters’ Sikorsky S-92A C-GZCH. (Transport Canada)

Examination of the the helicopter’s rotor blades showed that the main rotor was turning slowly at impact, and that the tail rotor was not turning at all.

The investigation revealed that two of three studs attaching the transmission oil filter bowl to the transmission housing had fractured from over-stressed fatigue fractures. This allowed the transmission oil to rapidly drain. This had occurred previously with another Sikorsky S-92A, VH-LOH, which made and emergency landing in Western Australia, 2 July 2008. Sikorsky determined that the original titanium studs should be replaced with steel studs and made changes to the Aircraft Maintenance Manual procedures.

The bevel gears of the transmission’s tail rotor drive pinion were completely stripped away, as a result of frictional heating of the transmission operating without oil, and resulted in a complete loss of tail rotor drive.

During the investigation, it was determined that Cougar Helicopters had not properly followed the mandatory procedures required by the Aircraft Maintenance Manual, which were intended to discover damaged studs prior to failure.

The flight crew misunderstood the aircraft systems, which led them to misdiagnose the problem. A factor was their previous training regarding transmission noise and vibration.

The flight crew had significant trouble controlling the helicopter following the tail rotor failure. Shutting down the engines prior to lowering the collective resulted in a significant loss of rotor r.p.m. As the aircraft pitched, rolled and yawed, they were unable to turn the helicopter into the wind. They began their autorotative flare at too high an altitude with too low airspeed, which resulted in a nearly vertical impact. Because of the very low main rotor r.p.m., the impact forces were high enough to destroy the helicopter.

Cougar Helicopters’ Sikorsky S-92A, C-GKKN, similar to C-GZCH. (Algkalv via Wikipedia)

Cougar 91 was a Sikorsky S-92A, registered C-GZCH (c/n 92-0048). The company had named the helicopter The Jeanne d’Arc Breeze. It had been completed by Sikorsky in 2006 at the Coatesville, Pennsylvania, plant. It was initially registered in the United States as N71143. The helicopter had accumulated a total of 2,194.3 flight hours (TTAF) since new, and 1,773 cycles.

The Sikorsky S-92A is a twin-engine medium lift transport helicopter with a single main rotor and tail rotor. The tricycle landing gear is retractable. The S-92 is a development of the Sikorsky S-70 Blackhawk military utility helicopter. It is operated by a flight crew of two, and carry nineteen passengers.

The helicopter has an overall length of 68 feet, 6 inches (20.879 meters) with rotors turning. The fuselage is 56 feet, 2 inches (17.120 meters) long, and has a maximum width across the sponsons of 12 feet, 9 inches (3.886 meters). The overall height is 17 feet, 11 inches (5.461 meters). The S-92A has an empty weight of 15,575 pounds (7,065 kilograms) and Maximum Takeoff Weight (MTOW) of 26,500 pounds (12,020 kilograms).

Sikorsky S-92 three-way illustration with dimensions (Sikorsky, a Lockheed Martin Company)

The S-92A has a four-bladed, fully-articulated main rotor with a diameter of 56 feet, 4 inches (17.170 meters). The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) The four-bladed tail rotor has a diameter of 11 feet, 0 inches (3.353 meters) and is mounted on the right side of the tail rotor pylon in tractor configuration. It is canted 30° to the left, allowing it to generate left as well as anti-torque thrust. The tail rotor turns clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)

Power is supplied by two General Electric CT7-8A turboshaft engines rated at 2,740 shaft horsepower, each. This is a single-spool, front-drive, free-turbine engine with a 5-stage axial-flow, 1-stage centrifugal-flow compressor section, and a 2-stage gas generator turbine and 2-stage free power turbine. The engine is equipped with a Full-Authority Digital Engine Control (FADEC) system. The CT7-8A is 4 feet, 0.8 inches (1.240 meters) long, 2 feet, 2.0 inches (0.660 meters) wide and 2 feet, 1.0 inches (0.635 meters) high. It weighs 542.0 pounds (245.8 kilograms).

The CT7-8A has a Maximum Continuous Power rating of 1,523 shaft horsepower at 44,660 r.p.m., Ng (22,200 r.p.m., Np). The Takeoff Power rating is 1,879 shaft horsepower for Take-off (5-minute limit). For emergency situations, the engine can produce 2,043 shaft horsepower at 46,340 r.p.m., Ng, for 30 seconds (One Engine Inoperative, or OEI).

The Sikorsky S-92A has a maximum continuous cruise speed of 151 knots (280 kilometers per hour). Its maximum speed, VNE, is 165 knots (306 kilometers per hour). The service ceiling is 15,000 feet (4,572 meters). It can hover in ground effect (HIGE) at 9,200 feet (2,804 meters) and out of ground effect (HOGE) at 6,700 feet (2,042 meters). With one engine inoperative, the helicopter’s service ceiling is 5,500 feet (1,676 meters). The maximum range, with 30-minute fuel reserve, is 480 nautical miles (889 kilometers).

The S-92A is certified for Category A operations, meaning that, if one engine fails during takeoff, it can either return to the takeoff point or continue to fly away on the remaining engine.

Depending on installed equipment, the S-92A can make an emergency ditching in up to Sea State 5 or 6. (Sea State 5, is defined as “rough” with wave heights from 2.5–4.0 meters, Sea State 6 is 4–6 meters, and “very rough”.)

More than 200 Sikorsly S-92s have been built in both civil an dmilitary variants since 1998. It remains in production, and has been selected as the next U.S. presidential helicopter, currently designated as VH-92A.

A Sikorsky S-92A twin-engine, medium-lift transport helicopter.

© 2017 Bryan R. Swopes

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12 March 1967

McDonnell F-4D Phantom II 66-7554. (Boeing)
McDonnell F-4D-30-MC Phantom II 66-7533, the 2,000th Phantom. (Boeing)

12 March 1967: McDonnell Aircraft Corporation, St. Louis, Missouri, delivered the 2,000th F-4 Phantom II to the United States Air Force. F-4D-30-MC 66-7533, c/n 2062, was assigned to the 40th Tactical Fighter Squadron, 33rd Tactical Fighter Wing, at  Eglin Air Force Base, Florida.

On 26 May 1967, the personnel and equipment of the 40th TFS were transferred to the 8th Fighter Wing based in Thailand. The aircraft were deployed across the Pacific Ocean, 26–28 May, with flights to Hickam Air Force Base, Honolulu, Hawaii; Anderson Air Force Base, Guam; and Ubon-Rachitani Royal Thai Air Force Base, Thailand. On 25 July 1967, an additional twenty F-4Ds arrived at Ubon RTAFB, having been transferred from the 4th TFS. 66-7533 was included in this later group of Phantoms.¹

On 19 September 1967, the 2,000th Phantom II was being flown by Major Lloyd Warren Boothby and 1st Lieutenant George H. McKinney, Jr., of the 435th Tactical Fighter Squadron. Following a Rolling Thunder attack on railroad sidings at Trung Quang, about 10 miles (16.1 kilometers) north of Phúc Yên, 66-7533 was hit in the right wing by a 57 mm anti-aircraft cannon shell. The airplane was badly damaged but “Boots” Boothby fought to keep it under control for as long as possible. Finally, he and McKinney were forced to eject, having come within about 35 miles (56.3 kilometers) of their base.

At the time of its loss, 66-7533 had accumulated 155 flight hours on its airframe (TTAF).

Distinguished Flying Cross (U.S. Air Force)

For their airmanship in trying to save their airplane, Major Boothby and Lieutenant McKinney were each awarded the Distinguished Flying Cross, which was presented to them by President Lyndon B. Johnson, 23 December 1967, in a pre-dawn ceremony at Korat Royal Thai Air Force Base.

Lieutenant McKinney is quoted in USAF F-4 Phantom II MiG Killer 1965–1968:

“In the hail of AAA over the target seven miles north of Hanoi on that day was a ‘Golden BB’ which opened a three-foot hole in the Phantom II’s right wing, froze the right spoiler full up, immediately drained two of the three hydraulic systems and generally turned the day to crap! I mumbled an egress heading (and a few dozen prayers) while ‘Boots’ used every increment of incredible aviation instincts, honed by countless hours at the edge of the envelope, to keep the F-4 airborne and headed away from the ‘Hanoi Hilton.’ Doing so required full manual depression of the left rudder pedal, and holding the stick within one inch of the left limit of travel.

“Despite the physical exertion, coupled with the precise touch necessary to remain airborne as the Black River receded behind the crippled Phantom II and rescue became at least a possibility, ‘Boots” managed to announce to the world on ‘Guard’ channel that they had so many warning lights lit up that it ‘looks like we’ve won a free game at the arcade.’ “

USAF F-4 Phantom II MiG Killer 1965–1968, by Peter E. Davies, Osprey Publishing, 2004, at Page 75.

[A number of sources state that Lt. McKinney did not survive the ejection, but this is incorrect. Both pilots were rescued by helicopter. McKinney went on to earn credit for 2.5 kills as a Weapons System Officer, and returned for another combat tour as an F-4 aircraft commander.]

Boothby
Lieutenant Colonel Lloyd Warren Boothby, United States Air Force

WASHINGTON (AFPN) — I’d hate to see an epitaph on a fighter pilot’s tombstone that says, “I told you I needed training”. . . How do you train for the most dangerous game in the world by being as safe as possible? When you don’t let a guy train because it’s dangerous, you’re saying, “Go fight those lions with your bare hands in that arena, because we can’t teach you to learn how to use a spear. If we do, you might cut your finger while you’re learning.” And that’s just about the same as murder. —Lt. Col. Lloyd “Boots” Boothby, April 17, 1931, to Nov. 26, 2006

That quote may seem a little extreme, but Colonel Boothby was referring to the Air Force’s urgent need to improve fighter tactics training, balanced against safety, but not at the expense of effectiveness.

Colonel Boothby, who passed away Nov. 26, was an experienced combat pilot and an academic instructor in the 57th Fighter Weapons Wing in the early 1970s. He looked at the Air Force’s declining kill ratio from Korea to Vietnam which was 2.4 to 1 in Vietnam compared to 8 to 1 in the Korean War. He led the effort to fix it. This involved several key steps, starting with a thorough analysis of the engagements over Vietnam.

Colonel Boothby led a series of studies at the Tactical Fighter Weapons Center, which were part of Project Red Baron, examining each of the war’s air-to-air battles. While the subsequent reports noted many accomplishments and even more lessons learned, they highlighted several significant trends. The colonel’s team discovered that pilots of multi-role fighters tended to have such a diverse range of missions that they seldom had a chance to master air combat tactics. They also noted pilots who were shot down rarely saw the enemy aircraft or even knew they were being engaged.

Additionally, few U.S. pilots, before flying into combat, had any experience against the equipment, tactics or capabilities of the enemy’s smaller, highly maneuverable fighters.

In short, the Red Baron Reports called for “realistic training (that) can only be gained through study of, and actual engagements with, possessed enemy aircraft or realistic substitutes.”

Based on this report and Colonel Boothby’s persuasiveness to get himself and Capt. Roger Wells access to an intelligence organization’s restricted collection of Soviet equipment, training manuals and technical data, they developed the dissimilar air combat training, or DACT, program to meet the Tactical Air Command’s initiative of “Readiness through Realism.”

Under the DACT program, Air Force officials had some T-38s painted with Soviet-style paint schemes and flew them based on adopted Soviet tactics.

Northrop F-5E Tiger II 74-01561 of the 64th Fighter Weapons Squadron, 57th Fighter Weapons Wing, in October 1976. (U.S. Air Force)

Because of his combat experience, academic instructor background, and involvement in Project Red Baron and in developing the DACT program, Colonel Boothby served as the first aggressor squadron’s commander when the 64th Fighter Weapons Squadron activated Oct. 15, 1972.

As an instructor, Colonel Boothby proved himself an effective teacher who relished the attention of his captive audience. Ever-animated and quick with a joke or “fighter” story to make a point, he told the pilots he was instructing what they needed to know to succeed. These qualities ensured his students’ attention remained spellbound and eager.

One former student recalled one of the colonel’s more popular attention steps. In typical fighter pilot stance, using his hands to represent a dogfight, he would spray lighter fluid from his mouth across his right hand (palming a lighter at the time) and literally flame the left hand and wristwatch bogie. He generally walked away with a few singed hairs on his hand, but his students received a magnificent visual demonstration of the seriousness of air combat.

Such object lessons ensured this charismatic instructor’s students learned and retained the knowledge they might need to save their lives one day.

Upon learning of Colonel Boothby’s death recently, Air Force Chief of Staff Gen. T. Michael Moseley noted:

“He. . . had an impact on how we do business and how we think about this air combat work. Folks out there like [Colonel Richard] Moody Suter and Boots Boothby have left a true legacy. I know one Texas public school-educated, land grant college graduate, F-15 weapons officer, Fighter Weapons Instructor Course instructor and ex-57th Wing commander who has certainly benefited from folks like this.”

—Ellery Wallwork, Air Force History Office, 5 December 2006

¹ Mr. F.C. Straile informed me that he crewed McDonnell F-4D Phantom II 66-7533 with the 4th Tactical Fighter Squadron at Eglin Air Force Base, Florida, and transferred along with it to the 435th TFS at Ubon RTAFB. Thanks, Mr. Straile!

Fred Straile (at far right) with the 2,000th Phantom, F-4D 66-7533. (Fred C. Straile collection)

© 2017, Bryan R. Swopes

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12 March 1955

Jean Boulet (1920–2011)
Chief Test Pilot Jean Boulet (1920–2011)

12 March 1955:  Société nationale des constructions aéronautiques du Sud-Est  (SNCASE, or Sud Aviation) Chief Test Pilot Jean Boulet and Flight Test Engineer Henri Petit made the first flight of the SE.3130 Alouette II prototype, F-WHHE, at Buc Airfield, near Paris, France.

Powered by a Societé Anonyme Turboméca Artouste IIB1 turboshaft engine, the Alouette II was the first gas turbine helicopter to enter series production. SNCASE would become Aérospatiale, later, Eurocopter, and is now Airbus Helicopters.

SNCASE SE.3130 Alouette II No. 01 prototype, F-WHHF, with test pilot Jean Boulet and Henri Petit, 12 March 1955. (Eurocopter)
SNCASE SE.3130 Alouette II No. 01 prototype, F-WHHE, with test pilot Jean Boulet and Henri Petit, 12 March 1955. (Airbus Helicopters)

The Alouette II is a 5-place light helicopter operated by a single pilot. The fuselage is 9.66 meters (31 feet, 9 inches) long. The three-bladed fully-articulated main rotor has a diameter of 10.20 meters (33 feet, 6 inches). It turns clockwise, as seen from above. (The advancing blade is on the left side of the helicopter.) Normal main rotor speed, NR, is 350–360 r.p.m. The two-blade anti-torque rotor is 1.81 meters (9 feet, 11.25 inches) in diameter and turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) It turns at 2,020 r.p.m.

The SE.3130 has an empty weight of 895 kilograms (1,973 pounds) and a maximum takeoff weight (MTOW) of 1,600 kilograms (3,527 pounds).

SNCASE SE.3130 No. 01, F-WHHE. (Airbus Helicopters)

The prototype was powered by one Turboméca Artouste IIB1 turboshaft engine. The Artouste IIB1 is a single-shaft turboshaft engine with a single-stage centrifugal flow compressor section and a three-stage axial-flow turbine. The turbine drives both the compressor and an output drive shaft through reduction gearbox. The engine operates at 33,500 r.p.m (N1), and is capable of producing 400 shaft horsepower. It was derated to 360 shaft horsepower at 5,780 r.p.m. (N2) for installation in the Alouette II.

The helicopter has a cruise speed 175 kilometers per hour (109 miles per hour) at Sea Level, and a maximum speed of 185 kilometers per hour (115 miles per hour) at Sea Level. VNE is 195 kilometers per hour (121 miles per hour.)

The service ceiling is 4,000 meters (13,123 feet) at 1,500 kilograms (3,307 pounds) gross weight. The absolute ceiling is 4,500 meters (14,764 feet). At 1,350 kilograms (2,976 pounds) the Alouette II has a hover ceiling in ground effect, HIGE, of 3,400 meters (11,155 feet) and hover ceiling out of ground effect of 1,900 meters (6,234 feet). At 1,500 kilograms the Alouette II’s HIGE is 2,000 meters (6,560 feet) and HOGE is 600 meters (1,968 feet).

The SE.3130 Alouette was in production from 1956 until 1975. It was marketed in the United States by the Republic Aviation Corporation’s Helicopter Division. More than 1,300 of these helicopters were built.

Jean Boulet hovers the prototype SE.3130 Alouette II, F-WHHF, 12 March 1955. (Eurocopter)
Jean Boulet hovers the prototype SNCASE SE.3130 No. 01, F-WHHE. (Airbus Helicopters)

Jean Boulet was born 16 November 1920, in Brunoy, southeast of Paris, France. He graduated from Ecole Polytechnique in 1940 and the Ecole Nationale Supérieure de l’aéronautique In 1942. As an officer of the Armée de l’Air (French Air Force) he was sent to the United States for training as a fighter pilot, and later as a helicopter pilot. In 1947 he  joined Société nationale des constructions aéronautiques du Sud-Est (SNCASE) as an engineer and test pilot. As a test pilot he made the first flight in every helicopter produced by SNCASE, which would become Sud-Aviation and later Aérospatiale (then, Eurocopter, and now, Airbus Helicopters). He set 24 Fédération Aéronautique Internationale world records for speed, distance and altitude. While flying a SE 530 Mistral fighter, 23 January 1953, he entered an unrecoverable spin and became the first French pilot to escape from an aircraft by ejection seat during an actual emergency. Médaille de l’Aéronautique. In 1972 he was appointed Officier de la Légion d’honneur. He had more than 9,000 flight hours with over 8,000 hours in helicopters.

Jean Boulet died at Aix-en-Provence, 15 February 2011, at the age of 90.

© 2017, Bryan R. Swopes

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