The World’s Loudest Plane Was So Loud It Caused Seizures

The aviation industry’s transition from propellers to jet engines saw the emergence of a new kind of engine called the turboprop. A turboprop engine is a turbine engine but instead of generating thrust from exhaust, the engine drives a propeller.

In 1955, the US Air Force developed an experimental aircraft called the XF-84H, manufactured by Republic Aviation. The purpose of the XF-84H was to determine whether it was possible for a fighter airplane to ditch the catapult and takeoff from a carrier on its own accord. A turboprop engine was chosen to power the aircraft, because such an engine uses big fans to move large volumes of air, which enables the aircraft to produce greater thrust at lower speeds. Bigger thrust means faster acceleration, which translates to shorter takeoffs.

Republic XF-84H Thunderscreech the loudest plane

The XF-84H was based on the well-known swept-winged F-84 Thunderstreak, but instead of a jet engine, the XF-84H was fitted with 5,850 hp Allison XT40-A-1 turboprop engine that turned three steel blades. With a sweep of 12 feet, the blades were so long that even at idling thrust the tip of the blades moved at supersonic speeds producing a continuous visible sonic boom that could be heard from 40 km away. The shockwaves were so powerful it could knock a full grown man down.

From Air&Space Magazine:

“One day, the crew took it out to an isolated test area [at Edwards Air Force Base in California] to run it up,” recalls Henry Beaird, a Republic test pilot at the time and one of only two men ever to fly the -84H. “They tied it down on a taxiway next to what they assumed was an empty C-47, but that airplane’s crew chief was inside, sweeping it out. Well, they cranked that -84H up, made about a 30-minute run, and shut it down. As they were getting ready to tow it back to the ramp, they heard this banging in the back of the C-47.” It was the crew chief, Beaird relates, knocked silly by the high-intensity noise and on his back on the floor of the –47, flailing his limbs. “He eventually came out of it,” Beaird recalls.

“As long as you stood ahead of or behind the airplane,” says Beaird, now 78 and flying Learjets, “it really wasn’t so bad, but if you got in the plane of the prop, it’d knock you down.” Really? “Really.”

The XF-84H’s horrendous noise earned the aircraft the nickname “Thunderscreech”.

The Thunderscreech’s engine ran at full speed all the time, and the propeller rotated at 2,100 rpm from startup until shutdown. Thrust was obtained and adjusted by changing the pitch of the blades. The response from the propellers was instantaneous. But the noise was terrible.

Edward von Wolffersdorff, Beaird’s crew chief, recalls:

I remember making my first ground runs with the thing, down on the main base, and I was wondering Why are they flashing that red light at me over on the control tower? It turned out they couldn’t hear a damn thing over their radios, so they kicked us out and sent us over to the north base.

Edwards feared that the shockwave from the propellers would break the windows in the control tower, located about a mile away from the runway. To prevent injury from a blown in window, whenever the XF-84H was flying, the traffic controllers would get under their desks with their radios and cover themselves with blankets.

“Nobody ever actually recorded the decibels,” recalls Beaird. “I think they were afraid the measuring device might get broken.”

Republic XF-84H Thunderscreech the loudest plane

Photo: US Air Force

The XF-84H was never well-liked at the Edwards Air Force Base, and it wasn’t solely for the noise. The XF-84H was an impractical machine that took half an hour just to warm up and be cleared for takeoff which made it clearly unsuited for combat. More than noise or delays, it was mechanical problems that led to its undoing.

The T40 turboprop engine was—in the words of the company’s own authorized history, Power of Excellence by William A. Schoneberger and Paul Sonnenburg—“a monstrosity, a mechanical nightmare.” The XF-84H suffered from vibrations that originated from the supersonic propellers and the powerful torque the engine produced. Lin Hendrix, one of the Republic test pilots assigned to the program, flew the aircraft once and refused to ever fly it again. “You aren’t big enough and there aren’t enough of you to get me in that thing again,” he told the formidable Republic project engineer.

The fearless Hank Beaird flew eleven times in that machine, and ten of those flights ended in forced landing. “By jingo, that airplane is going to hurt somebody!” Beaird once said after an emergency landing.

In the end, nobody wanted anything to do with the aircraft. First the Navy backed out and then the Air Force canceled the project after only two XF-84Hs was built with a total flight time of less than 10 hours between them.

The XF-84H was widely believed to be the fastest propeller-driven aircraft ever built, with an official top speed of 670 mph, as predicted by Republic, although neither of the two planes ever made it past 450 mph.

What happens when airline pilots are too eager to get airborne

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In aviation, a tailstrike is an event in which the rear empennage of an aircraft strikes the runway. This can happen during takeoff of a fixed-wing aircraft if the pilot pulls up too rapidly, leading to the rear end of the fuselage touching the runway. It can also occur during landing if the pilot raises the nose too aggressively. This is often the result of an attempt to land nearer to the runway threshold.

Tailstrike incidents are rarely dangerous in themselves but the aircraft must be thoroughly inspected and repairs may be difficult and expensive if the pressure hull is involved. Inadequate inspections and improper repairs to damaged airframes after a tailstrike have been known to cause catastrophic structural failure long after the tailstrike incident following multiple pressurization cycles .

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Military is not exempt from the phenomena

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A Very Large and Unusual Aircraft

The Scaled Composites Model 351 Stratolaunch is an aircraft built for Stratolaunch Systems by Scaled Composites to carry air-launch-to-orbit rockets. It was announced in December 2011 and rolled out in May 2017. The aircraft features a twin-fuselage design and the longest wingspan ever flown, at 385 feet (117 m), surpassing the Hughes H-4 Hercules flying boat of 321 feet (98 m). The Stratolaunch is intended to carry a 550,000-pound (250 t) payload and has a 1,300,000-pound (590 t) maximum takeoff weight. It should release its rocket at 35,000 ft (11,000 m).

The aircraft flew for the first and so far only time on April 13, 2019, and shortly thereafter, the company announced it would halt development of its air-launched family of launch vehicles following the death of Stratolaunch founder Paul Allen in October 2018. The company ceased operations the next month, and placed all company assets, including the aircraft, for sale for US$400 million by June 2019. Cerberus Capital Management acquired Stratolaunch Systems including the Stratolaunch aircraft in October 2019. Stratolaunch announced in December 2019 that it would now be focusing on offering high-speed flight test services.

Stratolaunch has a twin-fuselage configuration, each 238 ft (73 m) long and supported by 12 main landing gear wheels and two nose gear wheels, for a total of 28 wheels. The twin-fuselage configuration is similar to the Scaled Composites White Knight Two. Each fuselage has its own empennage.

The pilot, co-pilot and flight engineer are accommodated in the right fuselage cockpit.[2] The flight data systems are in the left fuselage. The left fuselage cockpit is unmanned with storage space for up to 2,500lb of mission specific support equipment. Both fuselage cockpits are pressurized and separated by a composite pressure bulkhead from the remainder of the unpressurized vehicle.

At 385 ft (117 m), it is the largest plane by wingspan, greater than a 300 ft (91 m) American football field. The main center section is made up of four primary composite spars supported by four secondary spars. The center section of the high-mounted, high aspect ratio wing is fitted with a Mating and Integration System (MIS), developed by Dynetics and capable of handling a 490,000 lb (220 t) load. The wing houses six main and two auxiliary fuel tanks, with the main tanks located inboard adjacent to an engine. The auxiliary tanks are located in the inboard wing where the load-carrying structure joins the fuselage.

Stratolaunch is powered by six Pratt & Whitney PW4056 engines positioned on pylons outboard of each fuselage, providing 56,750 lbf (252.4 kN) of thrust per engine. Many of the aircraft systems have been adopted from the Boeing 747-400, including the engines, avionics, flight deck, landing gear and other systems, reducing development costs.

It will require 12,000 ft (3,700 m) of runway to lift-off. It should release its rocket at 35,000 ft (11,000 m). It will carry a 550,000 lb (250 t) payload.[8] With a Pegasus II, it could deliver up to 13,500 lb (6.1 t) satellites to LEO or 4,500 lb (2.0 t) to a 15° GTO. It could launch a Dream Chaser small spaceplane capable of transporting astronauts or payloads within 24 hours. The stated goal is to carry up to three Orbital ATK “Pegasus XL” rockets for high-altitude launches by 2022.

Airline Ad has Daredevils Shadowing A380 Super Jumbo Jet Wearing Jetpacks

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Two real-life rocketeers wearing jet packs zoom up to and fly alongside a super jumbo airliner in an incredible new ad.

While you think it might be CGI-trickery, the video of the two daredevils zipping over the Dubai skyline in jet packs next to an A380 super jumbo jet is very, very real, CBS News reported.

The jaw-dropping footage is a promo video for Dubai’s Emirates airline.

Stuntmen Yves Rossy and Vince Reffet from Jetman Dubai soar some 4,000 feet above the city as they fly “up, up and away” in tandem with the world’s largest passenger plane.

The amazing aerial footage was filmed by a nearby helicopter.

Supersonic Business Passenger Jet Zooming in Over the Horizon

The Aerion AS2 is a supersonic business jet under development by Aerion Corporation. In May 2014, it was announced that the Aerion AS2 would be part of a larger Aerion SBJ redesign, which aimed for release after a seven-year developmental period. Aerion partnered with Airbus in September the same year. In December 2017, Airbus was replaced by Lockheed Martin. Its General Electric Affinity engine was unveiled in October 2018. In February 2019, Boeing replaced Lockheed Martin.

The Aerion AS2 12-passenger aircraft aims for Mach 1.6 with a supersonic natural laminar flow wing for a minimum projected range of 4,750 nm (8,800 km). A $4 billion development cost is anticipated, for a market of 300 over 10 years and 500 overall for $120 million each.

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In December 2017, Aerion and Lockheed Martin announced that they would explore its joint development without Airbus, aiming to fly in 2023 and be certificated in 2025. On December 15, after discussions with Lockheed’s Skunk Works, they announced a MoU to explore over a year the joint development of the supersonic business jet: engineering, certification and production. Lockheed previously developed supersonic aircraft like the F-16, the F-35, F-22, and the Mach 3+ SR-71, and they concluded that the AS2 concept warranted time and resource investment after reviewing Aerion’s aerodynamic technology. Throughout the two-and-a-half-year engineering collaboration with Airbus, Aerion advanced the AS2 aerodynamics and designed preliminary wing and airframe structures, a systems layout, and a fly-by-wire control system concept. Between May and December 2017, the GE collaboration resulted in moving the engines from the trailing edge to the wing leading edge, featuring a T-tail, and a higher wing aspect ratio.

Aerion said it is spending $1 billion for the AS2. Aerion and Lockheed wanted to freeze its engines, wings, and fuselage configuration in summer 2018, with the goal of selling 30 jets per year for $3.6 billion over 20 years.

 

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While military jets have had supersonic capabilities for decades, the economics are daunting for civilian operations. High ticket prices helped do in the Concorde after 27 years of service, which slurped twice as much fuel as a Boeing Co. jumbo jet while carrying only one-fourth as many passengers.

In the years since Air France and British Airways parked their Concordes, would-be supersonic jet developers have turned to business aircraft in hopes of putting newer technology in a smaller airframe to attract wealthy buyers and globe-trotting chief executive officers.

 

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Boeing 747-8 Private Jet takes Luxury to a Whole New Level

For most people, private jets such as the $65 million Gulfstream G650 or the Bombardier Global Series are the epitome of luxury air travel, but there are a select few who can afford more than that. They’re converting airliners into private flying palaces. To meet this demand, Airbus and Boeing have begun selling “VIP” versions of their airliners under the Airbus Corporate Jet and Boeing Business Jet brands. While most of these planes are based on smaller Airbus A320 series or Boeing 737 models, one recent VIP conversion took luxury to a new level.

One very lucky, very wealthy, and very confidential client took delivery of a personalized Boeing 747-8, completed by Greenpoint Technologies of Kirkland, Washington. Its incredible 4,786 sq. ft. of space features a stateroom, lounges, an office, and a massive dining room.

 

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Master Bedroom

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Upper Deck Lounge

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Time to relax at 40,000 feet

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Big Majestic Beast

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