10 out of 10 for engines...
- OFSO
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10 out of 10 for engines...
Enjoying a post-prandial meditation. Drone of propellers overhead. "Sounds like AN-22" I said to the wife. Reached for my tablet. An AN-12BK of Cavok Air heading south to Ghardaia in Afriky.
Re: 10 out of 10 for engines...
I was at home just north of Cambridge one Sunday afternoon. It was a lovely day, all the doors and windows open and I heard a sound. I'd never heard it before but for some reason I knew what it was, rushed outside just as the BBMF Lancaster flew over on its way back home, presumably after some event at Duxford.
- tango15
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Re: 10 out of 10 for engines...
Speaking of engines, I see that burners made by Rolls-Royce have been selected to keep the B-52 in service for at least another 15 years. A not inconsiderable order, given the number of engines, as John Major would have said. I'm not complaining, since they provide one of my pensions, but will those beasts ever be taken out of service?
https://www.janes.com/defence-news/defe ... e-engining
https://www.janes.com/defence-news/defe ... e-engining
Re: 10 out of 10 for engines...
A long time coming and a long way to go.
PP
PP
Re: 10 out of 10 for engines...
I would have thought that with improvements in engine technology they could replace each pair with a single engine that would outperform what it was replacing and improve fuel efficiency.
- Woody
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Re: 10 out of 10 for engines...
This isn’t my video, but I was in the crowd, there was a lot of dust in my eyes
When all else fails, read the instructions.
Re: 10 out of 10 for engines...
They could, but the aircraft has insufficient rudder authority to cope with an outboard engine failure if it's one of four, one of eight is manageable.
https://www.flightglobal.com/fixed-wing ... 26.article
The US Air Force (USAF) has awarded Rolls-Royce a $2.6 billion contract to replace the engines on its Boeing B-52H Stratofortress bomber fleet.
The award is for 608 examples of the company’s F130 engine, a military derivative of the BR725 business jet engine. The contract also includes spare engines, support equipment, engineering data and sustainment services, the USAF said on 24 September.
Re: 10 out of 10 for engines...
They will still have to cope with the dreaded 7- engine approach.
PP
PP
Re: 10 out of 10 for engines...
So what happens if they suffer a pylon failure and lose the two outboard engines on one side? I'm assuming it needs enough power that they can't just throttle back the outboard engines on the other side until they can fly in a straight line again.
Re: 10 out of 10 for engines...
Would it be any different than a 747 losing an outboard engine. Still loss of 25% of installed power.
If necessary, after reaching full rudder travel. reduce power on other outboard engine until straight flight can be maintained.
PP
If necessary, after reaching full rudder travel. reduce power on other outboard engine until straight flight can be maintained.
PP
Re: 10 out of 10 for engines...
It might have been someone on TOP who said that a 747, having climbed to FL350, has the same power to weight ratio on three engines as it has fully loaded on take off with four, I think in the context of the BA flight that lost an engine on take off from LAX and flew back to the UK on three. A 747 engine has about three times the thrust of what they fit on a B-52.
Re: 10 out of 10 for engines...
Huh! I was browsing the RB211 page on Wikipedia and came across this sentence:
Also interested to note that RR sold them to the Russians for the Tupolev Tu-204-120.The -535E4 was also proposed by Boeing for re-engining the B-52H Stratofortress, replacing the aircraft's eight TF33s with four of the turbofans.
Re: 10 out of 10 for engines...
B-52H
MTOW 488,000 lb
RR F130 17,000.00 lbf thrust X 8
B747-8
MTOW 987,000 lb
GEnx-2B67 66,500 lbf X4
Pretty much equal thrust to weight ratios.
PP
MTOW 488,000 lb
RR F130 17,000.00 lbf thrust X 8
B747-8
MTOW 987,000 lb
GEnx-2B67 66,500 lbf X4
Pretty much equal thrust to weight ratios.
PP
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Re: 10 out of 10 for engines...
Woody; Good video, but the soundtrack (the most important part) was spoiled by a very annoying 'clicking' noise.
You only live twice. Once when you're born. Once when you've looked death in the face.
Re: 10 out of 10 for engines...
Think it was from a camera.Pinky the pilot wrote: ↑Tue Sep 28, 2021 11:02 amWoody; Good video, but the soundtrack (the most important part) was spoiled by a very annoying 'clicking' noise.
Re: 10 out of 10 for engines...
Camera(s) used per credits
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- TheGreenGoblin
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Re: 10 out of 10 for engines...
The early B52's had issues with the fagility of the rudder/fin, so flying with power totally out on one wing would have been a total "no no" on the basis of the fragile fin alone!llondel wrote: ↑Tue Sep 28, 2021 1:17 amSo what happens if they suffer a pylon failure and lose the two outboard engines on one side? I'm assuming it needs enough power that they can't just throttle back the outboard engines on the other side until they can fly in a straight line again.
On Jan. 10, 1964 a Boeing B-52H Stratofortress instrumented by Boeing-Wichita was being used to test buffeting turbulence effects on aircraft.
The crew, headed by test pilot Charles F. “Chuck” Fisher, was performing an eight hour flight that would test indicated airspeeds of 280, 350 and 400 knots over mountainous terrain at 500 feet altitude above the ground.
Since during the mission the turbulence became very strong the crew discontinued the mission and climbed to 14,000 feet. Then the aircraft was moved sharply to the right and sideways through the air by a sudden five second blast of clear air turbulence which ripped off the vertical fin. As told by Walter J. Boyne in his book Boeing B-52 A Documentary History, Fisher stated that it felt like a severe edged blow, followed by several more. Instantaneously the aircraft rolled to the left at high rate, the nose swinging up and to the right rapidly. Fisher reduced power to idle and the B-52 rotated nose down.
He then applied full opposite controls without any effect since the rudder pedals were locked. Fisher was able to reduce the airspeed down to 210 knots by applying airbrakes. With 80 degrees of wheel deflection, he was able to stabilize the aircraft in somewhat level flight.
The three hours that followed involved some very sensitive flight: in fact even if the crew knew how important it was to get the instrumented aircraft back safely (so that the data of an incident which had caused other crashes would be preserved), they had no idea if the damage would propagate, throwing the aircraft out of control.
Long time test pilot Dale Felix took off in a North American F-100 to act as chase aircraft. Felix joined up with the B-52 and while he was surveying the damage he heard Fisher remarking “we’ve slowed down to 220 knots, we’re stable, and I’m going to handle it pretty carefully.” Felix cut in with “Chuck, that’s a good idea,” and added “All of your rudder and most of your vertical fin are gone.”
As reported by Boyne, there was a silence and Fisher said “Don’t I even have 50%?” Felix replied “No, you don’t have 50%.” Actually there was only about 15% of the fin remaining.
The aft main gear was lowered to gain some lateral directional stability.
The crew was ready to eject but Fisher along with the co-pilot Dick Curry decided they could try to land the aircraft. The aircraft was carefully flown to Blytheville Air Force Base (AFB), Arkansas, where the wind was straight down the runway and an approach could be made over an unpopulated area. Fisher brought the aircraft in, flaps up. He recalls “the landing was not my best one but the airplane was drifting left off the runway and the only way to stop it was to get it on the ground.”
The data collected by the instrumented B-52 showed that even if some improvements in structure could be made, no aircraft could be made safe from most extreme values of clear air turbulence. The best way to avoid such accidents was to plan flights to stay away from it.
The following video film is an Aerospace Flight Safety report released by the U.S. Air Force (USAF) which details the events that occurred, with supporting footage from chase aircraft and ground cameras.
https://theaviationgeekclub.com/look-ma ... -tail-fin/
Though you remain
Convinced
"To be alive
You must have somewhere
To go
Your destination remains
Elusive."
Convinced
"To be alive
You must have somewhere
To go
Your destination remains
Elusive."
- TheGreenGoblin
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Re: 10 out of 10 for engines...
Here is a more detailed report on Rolls Royce's engine win in the USA...
https://www.flightglobal.com/fixed-wing ... 26.articleThe US Air Force (USAF) has awarded Rolls-Royce a $2.6 billion contract to replace the engines on its Boeing B-52H Stratofortress bomber fleet.
The award is for 608 examples of the company’s F130 engine, a military derivative of the BR725 business jet engine. The contract also includes spare engines, support equipment, engineering data and sustainment services, the USAF said on 24 September.R-R beat bids from GE Aviation and Pratt & Whitney. Though R-R is based in the UK, the F130 will be manufactured in Indianapolis, Indiana.
The R-R F130 engine will replace the P&W TF33-PW-103 turbofan, which has powered the B-52 fleet since the 1960s. The USAF believes that ageing turbine is not sustainable beyond 2030.
“The B-52 Commercial Engine Replacement Program is the most important and comprehensive upgrade to the B-52 in over half a century,” says Major General Jason Armagost, director of strategic plans, programmes and requirements with USAF Global Strike Command. “The B-52 is the workhorse of the nation’s bomber force and this modification will allow the B-52 to continue its critical conventional and standoff mission into the 2050’s.”
The USAF has 76 examples of the Stratofortress in its fleet. Each bomber has eight engines.
The strategic heavy bomber can be used for a wide variety of missions, including dropping nuclear and conventionally-armed bombs, close-air support, air interdiction, offensive counter-air and maritime strike.
Boeing is contracted to integrate the engines with the bombers. It will modify the first two B-52Hs by the end of 2025 ahead of ground and flight testing. The first lot of re-engined B-52Hs are to be finished by the end of 2028, with the entire fleet re-engined by 2035.
The new engines are expected to remain on the B-52H through the end of its service life. The USAF anticipates the turbines will increase fuel efficiency and range, while reducing maintenance costs.
Though you remain
Convinced
"To be alive
You must have somewhere
To go
Your destination remains
Elusive."
Convinced
"To be alive
You must have somewhere
To go
Your destination remains
Elusive."
- TheGreenGoblin
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Re: 10 out of 10 for engines...
More engine news of the adaptive engine sort.
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https://www.flightglobal.com/fixed-wing ... 13.articleThe US Air Force (USAF) plans to start testing adaptive engine prototypes from GE Aviation and Pratt & Whitney in early fiscal year 2022.
Tests on the two engine designs – GE’s XA100 and P&W’s XA101 – will run throughout the year at Arnold AFB’s Engineering Development Complex near Tullahoma in Tennessee, the USAF Materiel Command said on 22 September.
The USAF’s Adaptive Engine Transition Program (AETP) is intended to provide a 30% increase in range, an 18% decrease in acceleration time and improved thermal management compared to the P&W F135 engine that is currently fielded in the Lockheed Martin F-35 stealth fighter, according to the USAF Materiel Command.
Adaptive engines work by changing the volume of air flow that bypasses the turbine core by opening a third stream when flying in cruise mode. This third flow – in addition to the core flow and bypass turbofan flow – increases efficiency.
Alternatively, in high-thrust mode an adaptive engine directs the majority of air through the engine’s core and bypass turbofan streams, delivering greater thrust for combat manoeuvering. The third flow also has a cooling effect, allowing the core to run hotter, which further increases fuel efficiency.
The USAF is interested in re-engining the F-35A with an adaptive engine to increase the aircraft’s 1,200nm (2,220km) range, which is viewed as too short for attacking targets within China.
The service says it has already performed a digital fit check to show that the two adaptive engines will integrate with the stealth fighter. Physical fit checks are not yet planned, it says.
The F-35’s current F135 engine has been plagued with a number of issues, including components problems, part shortages and unaddressed repair needs caused by lack of depot capacity. As a result, 46 USAF F-35As were grounded last week, said Lieutenant General Clinton Hinote, deputy chief of staff for strategy, integration and requirements on 20 September during the Air Force Association’s Air, Space and Cyber Conference in National Harbor, Maryland.
In order to improve quality and reduce costs, US House Armed Service Committee Chairman Adam Smith has advocated using AETP as the basis for an engine replacement competition for the F-35.
However, General Arnold Bunch, commander of USAF Materiel Command, said on 20 September that he is not ready to commit to replacing the F135 with an adaptive engine. It may make more sense to adopt technology improvements developed from AETP in a piecemeal fashion, he says.
Ultimately, he sees the goal of AETP as advancing cutting edge jet turbine technology. “It’s an area that we have a decided advantage today and we need to keep that decided advantage,” says Bunch.
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Though you remain
Convinced
"To be alive
You must have somewhere
To go
Your destination remains
Elusive."
Convinced
"To be alive
You must have somewhere
To go
Your destination remains
Elusive."