• Hi Guest! Forum rules have been updated. All users please read here.

Boeing proposes high-speed Apache, heavier Chinook

Triton

Donald McKelvy
Senior Member
Joined
Aug 14, 2009
Messages
9,719
Reaction score
498
Website
deeptowild.blogspot.com
"Boeing proposes high-speed Apache, heavier Chinook"
By: Stephen Trimble
Washington DC

Source:
http://www.flightglobal.com/news/articles/boeing-proposes-high-speed-apache-heavier-chinook-400777/

As the US Department of Defense pursues a family of high-speed rotorcraft, Boeing officials say two stalwarts of the current fleet – the AH-64 Apache and CH-47 Chinook – must be kept viable for decades to come.

The AH-64E entered service last year, but an F-model is already on the drawing boards. Some upgrades – the 3,000shp turboshaft in development under the army’s improved turbine engine programme (ITEP) – have been openly discussed.

Boeing officials also believe high-speed capabilities can be added to the 40-year-old Apache design. Possibilities include adding a retractable landing gear, wingstubs to offload lift from a single main rotor in high-speed cruise and a tail rotor that articulates 90° to provide forward thrust.

Meanwhile, Boeing is scheduled to deliver the last CH-47F in Fiscal 2019, ending a production run that began in 1961. Boeing now is proposing to remanufacture F-models with a higher gross weight.

In the past, Boeing has proposed a 31,800kg (70,000lb) class variant with a 30cm (1in) wider fuselage to accommodate up-armoured HMMWV (Humvee) trucks. Budget realities have forced the company to propose a more modest solution now. The “H-model” CH-47, as proposed, strengthens the airframe and the propulsion system to lift 24,500kg, or about 1,810kg more than the existing helicopter.

The proposals seem to clash with the company’s interests in the Future Vertical Lift (FVL) programme. Boeing has teamed with Sikorsky to develop the high-speed SB-1 Defiant for the joint multi-role technology demonstrator (JMR-TD), which is a intended to be a scaled down version of the FVL-Medium concept to replace the Sikorsky UH-60 Black Hawk after 2030.

Boeing insists there is no contradiction, however.

“The issue is it takes a long time to develop an aircraft and field it, and we [and] the army have to keep the current fleet viable and relevant,” says Mike Burke, Boeing’s director of business development for attack helicopters.

David Palm, director of business development for vertical lift, also notes that the AH-64 is not scheduled to be replaced by the attack version of the FVL aircraft until 2040. The CH-47F is not due for retirement until 2060, a full century after its first flight.

“We believe there’s going to be another – at least one more – turn of the Apache technology,” Palm says.

Boeing’s agreement with Sikorsky on the SB-1 allows both companies to transfer technologies developed for the JMR-TD programme to aircraft already in production.
 

sferrin

ACCESS: USAP
Senior Member
Joined
Jun 3, 2011
Messages
13,369
Reaction score
1,407
They had me right to "articulating tail". That's a deal-killer right there.
 

bobbymike

ACCESS: USAP
Joined
Apr 21, 2009
Messages
10,281
Reaction score
1,234
sferrin said:
They had me right to "articulating tail". That's a deal-killer right there.

Obviously a question for the engineers but wouldn't it be easier to replace the tail rotor with a pusher propeller like the S-97?
 

Triton

Donald McKelvy
Senior Member
Joined
Aug 14, 2009
Messages
9,719
Reaction score
498
Website
deeptowild.blogspot.com
bobbymike said:
Obviously a question for the engineers but wouldn't it be easier to replace the tail rotor with a pusher propeller like the S-97?

What about torque and fuselage rotation? Wouldn't a S-97-style pusher propeller also require a coaxial main rotor?
 

bobbymike

ACCESS: USAP
Joined
Apr 21, 2009
Messages
10,281
Reaction score
1,234
Triton said:
bobbymike said:
Obviously a question for the engineers but wouldn't it be easier to replace the tail rotor with a pusher propeller like the S-97?

What about torque and fuselage rotation? Wouldn't a S-97-style pusher propeller also require a coaxial main rotor?

Probably showing my ignorance of vertical lift/forward flight requirements but;

1) If you have a conventional tail rotor for take off and landing that 'rotates 90 degrees' in flight for speed, becomes a pusher propeller, (just specualting from the original article) then you wouldn't need a co-axial main rotor?
 

circle-5

ACCESS: Top Secret
Top Contributor
Senior Member
Joined
May 31, 2009
Messages
1,159
Reaction score
128
bobbymike said:
Triton said:
bobbymike said:
Obviously a question for the engineers but wouldn't it be easier to replace the tail rotor with a pusher propeller like the S-97?

What about torque and fuselage rotation? Wouldn't a S-97-style pusher propeller also require a coaxial main rotor?

Probably showing my ignorance of vertical lift/forward flight requirements but;

1) If you have a conventional tail rotor for take off and landing that 'rotates 90 degrees' in flight for speed, becomes a pusher propeller, (just specualting from the original article) then you wouldn't need a co-axial main rotor?

As speed increases, the main rotor gets progressively off-loaded and behaves more like a gyrocopter, obviating the need for a dedicated anti-torque rotor. At speed, the Lockheed AH-56 transferred over 90% of its power to its pusher prop.
 

bobbymike

ACCESS: USAP
Joined
Apr 21, 2009
Messages
10,281
Reaction score
1,234
circle-5 said:
bobbymike said:
Triton said:
bobbymike said:
Obviously a question for the engineers but wouldn't it be easier to replace the tail rotor with a pusher propeller like the S-97?

What about torque and fuselage rotation? Wouldn't a S-97-style pusher propeller also require a coaxial main rotor?

Probably showing my ignorance of vertical lift/forward flight requirements but;

1) If you have a conventional tail rotor for take off and landing that 'rotates 90 degrees' in flight for speed, becomes a pusher propeller, (just specualting from the original article) then you wouldn't need a co-axial main rotor?

As speed increases, the main rotor gets progressively off-loaded and behaves more like a gyrocopter, obviating the need for a dedicated anti-torque rotor. At speed, the Lockheed AH-56 transferred over 90% of its power to its pusher prop.

Thank you why I love this forum so much knowledge!
 

Triton

Donald McKelvy
Senior Member
Joined
Aug 14, 2009
Messages
9,719
Reaction score
498
Website
deeptowild.blogspot.com
circle-5 said:
As speed increases, the main rotor gets progressively off-loaded and behaves more like a gyrocopter, obviating the need for a dedicated anti-torque rotor. At speed, the Lockheed AH-56 transferred over 90% of its power to its pusher prop.

The Sikorsky S-66 Advanced Aerial Fire Support System (AAFSS) proposal had a Rotorprop that swiveled 90 degrees to be both the tail rotor in hover and a pusher propeller in cruise. Sikorsky also built and flight tested the Rotoprop concept on a company owned S-61A, civilian version of the SH-3 Sea King.
http://www.secretprojects.co.uk/forum/index.php/topic,2145.msg14893.html#msg14893
 

Kiltonge

Greetings Earthling
Joined
Jan 24, 2013
Messages
202
Reaction score
12
Interesting to watch the H-47 slowly approach and exceed the capbilities of the Mi-6, which was roughly contemporaneous ( 1961 vs 1957 ).

Installed power on the 47F is about 8% more than a Mi-6 and the Block 2 with new blades should lift a similar payload ( c. 12,000 kg ).

Perhaps Mil was a little premature in stopping production in 1981!
 

sferrin

ACCESS: USAP
Senior Member
Joined
Jun 3, 2011
Messages
13,369
Reaction score
1,407
Kiltonge said:
Interesting to watch the H-47 slowly approach and exceed the capbilities of the Mi-6, which was roughly contemporaneous ( 1961 vs 1957 ).

Installed power on the 47F is about 8% more than a Mi-6 and the Block 2 with new blades should lift a similar payload ( c. 12,000 kg ).

Perhaps Mil was a little premature in stopping production in 1981!

The CH-53K has as much installed horsepower as an Mi-26. :eek:
 

Jemiba

ACCESS: Above Top Secret
Staff member
Top Contributor
Senior Member
Joined
Mar 11, 2006
Messages
8,221
Reaction score
926
Kiltonge said:
Perhaps Mil was a little premature in stopping production in 1981!

It was replaced by the Mi 26, which is still produced, so the US manufacturers just drew level.
 

sferrin

ACCESS: USAP
Senior Member
Joined
Jun 3, 2011
Messages
13,369
Reaction score
1,407
Jemiba said:
Kiltonge said:
Perhaps Mil was a little premature in stopping production in 1981!

It was replaced by the Mi 26, which is still produced, so the US manufacturers just drew level.

By choice. There are a boatload of designs that would have easily surpassed the Mi-26 but there was no requirement for them. Even the CH-53K mainly has that amount of power so it can retain a large amount of power in hot/high conditions rather than use it for maximum lift capability.
 

Grey Havoc

The path not taken.
Senior Member
Joined
Oct 9, 2009
Messages
11,753
Reaction score
1,899
https://www.flightglobal.com/news/articles/honeywell-pitches-upgraded-t55-engine-for-chinook-430086/

https://www.flightglobal.com/news/articles/army-will-not-pursue-ah-64f-model-apache-430045/
 

sferrin

ACCESS: USAP
Senior Member
Joined
Jun 3, 2011
Messages
13,369
Reaction score
1,407
Grey Havoc said:
https://www.flightglobal.com/news/articles/army-will-not-pursue-ah-64f-model-apache-430045/

That would seem to make the 3000 shp advanced turbines from P&W and GE redundant. ( HPW3000 & GE3000 respectively) I'm betting they'll have to go with an F model as there won't be money for a new design by then.
 

Similar threads

Top