Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
convair880mfan
Topic Author
Posts: 253
Joined: Fri Jun 25, 2021 12:33 am

Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 1:06 am

I know the Boeing 767 has a RAT and I think the Lockheed L-1011 Tristar had one too. Don't know what utilities they powered. I don't think the Boeing 707, 727 or early 737's had them. In the dark about the 747,757,777,787. And am clueless about Airbus products and other airliner types like regional jets. Does anyone know?

I imagine pilots and mechanics know. They probably also know if RAT type machines provide hydraulic and/or electric backup.

Thanks in advance for any information.
 
User avatar
Starlionblue
Posts: 20867
Joined: Fri Feb 27, 2004 9:54 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 1:26 am

A330/A340 - RAT powers the green hydraulic system only. Emergency electrical generation through the emergency generator, powered by the green system. RAT is housed in the third flap track fairing on the right wing.

A350 - RAT drives the emergency electrical generator only. Emergency hydraulic power through self-contained surface actuators. RAT housed in the right-hand side wing-body fairing, aft of the wing.
 
GalaxyFlyer
Posts: 8595
Joined: Fri Jan 01, 2016 4:44 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 1:50 am

CRJ has a air-driven generator, a RAT by another name, it powers the emergency bus which, in turn, powers an AC hydraulic pump. Right hand under the co-pilot’s foot. All other Challenger 600 types and Globals are the same. The 747 didn’t have a RAT until the -8.
 
User avatar
tb727
Posts: 2307
Joined: Thu Jun 30, 2005 1:40 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 1:51 am

A320 series has a RAT. The RAT powers the blue hydraulic system and can power an emergency generator which is turned by hydraulic power.

It is on the belly just forward of the main gear well on the left side.


And the 727 did not have one.
 
convair880mfan
Topic Author
Posts: 253
Joined: Fri Jun 25, 2021 12:33 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 2:14 am

I don't know if Wikipedia can be counted on, but according to them the Vickers VC-10 had a RAT and the A-380 has the largest RAT propeller in the world.

I imagine that if the 727 didn't have one, that the 707 didn't have one. Anyone know about other Boeing jetliners?
Thanks for all responses so far!
 
User avatar
AirKevin
Posts: 865
Joined: Wed Apr 26, 2017 2:18 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 2:23 am

The 747-8 is the only 747 that has one. The 757, 777, and 787 have one.
 
JustAnFO
Posts: 42
Joined: Tue Jul 10, 2012 5:47 pm

Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 3:36 am

MD-11 has an ADG (McD-speak for a RAT) that provides electric power by default when deployed, and can also supply limited hydraulic power if needed.

707, 727, 737 – no RAT.
757 – it has a RAT which powers the center hydraulic system, which supplies the primary flight controls, if the left and right hydraulic systems fail. I believe the 767 has a similar system, but I haven’t been trained on that type.


Sent from my iPhone using Tapatalk
 
User avatar
fr8mech
Posts: 8392
Joined: Mon Sep 26, 2005 9:00 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 3:48 am

The B767 and The B757 have a RAT that drives the center hydraulic system to provide power for the flight controls.

The RAT on the A300 provides power to the yellow hydraulic system for the flight controls.

The MD11 has an Air Driven Generator that provides AC power to the #1 auxiliary hydraulic pump or the emergency busses, depending on flight crew selection.

The B747-8 has a RAT that powers selected flight controls through the #3 system.
 
User avatar
Starlionblue
Posts: 20867
Joined: Fri Feb 27, 2004 9:54 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 4:16 am

A380 - RAT drives the emergency electrical generator only. Emergency hydraulic power through self-contained surface actuators. RAT housed in first flap track fairing on the left wing. As mentioned above, it is the largest RAT prop in the world, at 163cm in diameter.
 
Redbellyguppy
Posts: 257
Joined: Sat Apr 01, 2017 3:57 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 8:18 am

737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.
 
User avatar
Starlionblue
Posts: 20867
Joined: Fri Feb 27, 2004 9:54 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 8:31 am

Redbellyguppy wrote:
737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.


The muscle-powered actuators...

What about emergency electric generation? Windmilling engines, only batteries, or a dozen hamsters running inside a ball?
 
battlegroup62
Posts: 70
Joined: Mon Jul 03, 2017 5:05 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 9:02 am

Starlionblue wrote:
Redbellyguppy wrote:
737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.


The muscle-powered actuators...

What about emergency electric generation? Windmilling engines, only batteries, or a dozen hamsters running inside a ball?


Perhaps they'll start using piezoelectric generators in the pilot's seat cushions. Plenty of power when there is an emergency due to pucker.
 
User avatar
Starlionblue
Posts: 20867
Joined: Fri Feb 27, 2004 9:54 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 10:26 am

battlegroup62 wrote:
Starlionblue wrote:
Redbellyguppy wrote:
737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.


The muscle-powered actuators...

What about emergency electric generation? Windmilling engines, only batteries, or a dozen hamsters running inside a ball?


Perhaps they'll start using piezoelectric generators in the pilot's seat cushions. Plenty of power when there is an emergency due to pucker.


:rotfl: :rotfl: :rotfl:
 
celestar345
Posts: 78
Joined: Wed May 08, 2013 5:35 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 10:58 am

fr8mech wrote:
The B767 and The B757 have a RAT that drives the center hydraulic system to provide power for the flight controls.


For 767 (I assume same for 757) the RAT drives the center hydraulic, and the hydraulic motor generator gives out electricity from hydraulic power.
 
Woodreau
Posts: 2175
Joined: Mon Sep 24, 2001 6:44 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 11:57 am

Since all of the other planes are covered to finish out the regional jets

The EMB-145 does not have a RAT. No hydraulics other than what is in the accumulators The elevator is manually controlled with no hydraulics in normal conditions. The ailerons and rudder are hydraulic with control via pulleys and cables when hydraulics are lost. no emergency electrical generation other than the batteries. After the batteries die you have no electrical power. So you have that long 30 minutes I think I don’t remember- to get the plane on the ground before you lose the flight displays and lose the ability to trim the stabilizer. You can try to start the APU but if it fails to start then you now have less time to get on the ground.

EMB-175 does have one.


I have flown a CRJ-700 when it was only powered by the ADG. It sounds like someone started a lawnmower in the flight deck. Lose both FMSes and autopilots. The cabin depressurizes and the only functioning seat really is the captain seat. He has the only set of flight instruments that still work and you only have VHF1 and TXDR 1. Asked for radar vectors I don’t remember the interphone working or maybe it did but it was hard to hear the other pilot over the RAT propeller noise. Flaps and slats operate at half speed. Manual landing gear deployment and after landing you lose the last two remaining screens as the RAT stops generating power when the airspeed drops.
 
JustAnFO
Posts: 42
Joined: Tue Jul 10, 2012 5:47 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 12:37 pm

Starlionblue wrote:
Redbellyguppy wrote:
737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.


The muscle-powered actuators...

What about emergency electric generation? Windmilling engines, only batteries, or a dozen hamsters running inside a ball?

Armstrong power!

Only the main ship’s battery, which is certified to make one APU start attempt, and then provide 30 minutes of power to the captain’s instruments, one comm radio, and one nav radio.
An aux battery was a customer option on the 737 NGs, which I believe doubled that time to 60 minutes.


Sent from my iPhone using Tapatalk
 
GalaxyFlyer
Posts: 8595
Joined: Fri Jan 01, 2016 4:44 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 1:35 pm

Woodreau wrote:
Since all of the other planes are covered to finish out the regional jets

The EMB-145 does not have a RAT. No hydraulics other than what is in the accumulators The elevator is manually controlled with no hydraulics in normal conditions. The ailerons and rudder are hydraulic with control via pulleys and cables when hydraulics are lost. no emergency electrical generation other than the batteries. After the batteries die you have no electrical power. So you have that long 30 minutes I think I don’t remember- to get the plane on the ground before you lose the flight displays and lose the ability to trim the stabilizer. You can try to start the APU but if it fails to start then you now have less time to get on the ground.

EMB-175 does have one.


I have flown a CRJ-700 when it was only powered by the ADG. It sounds like someone started a lawnmower in the flight deck. Lose both FMSes and autopilots. The cabin depressurizes and the only functioning seat really is the captain seat. He has the only set of flight instruments that still work and you only have VHF1 and TXDR 1. Asked for radar vectors I don’t remember the interphone working or maybe it did but it was hard to hear the other pilot over the RAT propeller noise. Flaps and slats operate at half speed. Manual landing gear deployment and after landing you lose the last two remaining screens as the RAT stops generating power when the airspeed drops.


Not sure why the cabin depressurization, sure didn’t on the Challengers or Globals and if I’ve done one drop test, I’ve done two dozen. Yes, very noisy.
 
Tristarsteve
Posts: 3706
Joined: Tue Nov 22, 2005 11:04 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 4:42 pm

An aux battery was a customer option on the 737 NGs, which I believe doubled that time to 60 minutes.

Our B737-400 had a second battery at the rear of the e and e bay.

I don't know if Wikipedia can be counted on, but according to them the Vickers VC-10 had a RAT and the A-380 has the largest RAT propeller in the world.

The Vickers VC10 had two RATs, One electric and one hydraulic!
 
convair880mfan
Topic Author
Posts: 253
Joined: Fri Jun 25, 2021 12:33 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 5:58 pm

Thanks so very much for all that information. I think that provides almost a complete picture except for the DC-10 and some now retired British types like the BAC-111 and so on. Thanks again.
 
SteelChair
Posts: 1745
Joined: Fri Aug 25, 2017 11:37 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Thu Sep 30, 2021 10:09 pm

Redbellyguppy wrote:
737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.


One of the greatest misconceptions in aviation. 737 has cables to the hydraulic fight flight control actuators, with manual reversion in some instances.
 
User avatar
fr8mech
Posts: 8392
Joined: Mon Sep 26, 2005 9:00 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Fri Oct 01, 2021 12:00 am

celestar345 wrote:
For 767 (I assume same for 757) the RAT drives the center hydraulic, and the hydraulic motor generator gives out electricity from hydraulic power.


No, on both the B757 and B767 the flight controls are powered directly by the RAT.

Our B767's do have a Hydraulic Motor Generator (HMG) and does run off the center system, but it only activates if there is a complete loss of AC power. It powers the capt's flight instruments and selected other users on the aircraft. The HMG can not carry the center hydraulic pumps.
 
SteelChair
Posts: 1745
Joined: Fri Aug 25, 2017 11:37 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Fri Oct 01, 2021 1:41 pm

Tristarsteve wrote:
An aux battery was a customer option on the 737 NGs, which I believe doubled that time to 60 minutes.

Our B737-400 had a second battery at the rear of the e and e bay.

I don't know if Wikipedia can be counted on, but according to them the Vickers VC-10 had a RAT and the A-380 has the largest RAT propeller in the world.

The Vickers VC10 had two RATs, One electric and one hydraulic!


And the 777 has only one RAT, but it has both an electrical generator and a hydraulic pump on it.
 
User avatar
fr8mech
Posts: 8392
Joined: Mon Sep 26, 2005 9:00 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Fri Oct 01, 2021 5:41 pm

fr8mech wrote:
celestar345 wrote:
For 767 (I assume same for 757) the RAT drives the center hydraulic, and the hydraulic motor generator gives out electricity from hydraulic power.


No, on both the B757 and B767 the flight controls are powered directly by the RAT.

Our B767's do have a Hydraulic Motor Generator (HMG) and does run off the center system, but it only activates if there is a complete loss of AC power. It powers the capt's flight instruments and selected other users on the aircraft. The HMG can not carry the center hydraulic pumps.


My apologies. I misread your post. As you can see from my reply, you’re correct.

I thought you meant the RAT provided power to the HMG so that the center pumps could be powered…which really makes no sense. Need to stop posting before I’ve had my 4th cup of coffee.
 
Redbellyguppy
Posts: 257
Joined: Sat Apr 01, 2017 3:57 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sat Oct 02, 2021 5:50 am

SteelChair wrote:
Redbellyguppy wrote:
737 has cables going to flight controls, actuated by a person. These people powered generators consume cheap coffee and garbage airport food.


One of the greatest misconceptions in aviation. 737 has cables to the hydraulic fight flight control actuators, with manual reversion in some instances.




While factually correct that’s not nearly as funny.
 
celestar345
Posts: 78
Joined: Wed May 08, 2013 5:35 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sat Oct 02, 2021 11:56 pm

fr8mech wrote:
fr8mech wrote:
celestar345 wrote:
For 767 (I assume same for 757) the RAT drives the center hydraulic, and the hydraulic motor generator gives out electricity from hydraulic power.


No, on both the B757 and B767 the flight controls are powered directly by the RAT.

Our B767's do have a Hydraulic Motor Generator (HMG) and does run off the center system, but it only activates if there is a complete loss of AC power. It powers the capt's flight instruments and selected other users on the aircraft. The HMG can not carry the center hydraulic pumps.


My apologies. I misread your post. As you can see from my reply, you’re correct.

I thought you meant the RAT provided power to the HMG so that the center pumps could be powered…which really makes no sense. Need to stop posting before I’ve had my 4th cup of coffee.


The problem with 767 is that with so much variations and configurations you won't know what aircraft would have some special capabilities...

I still remember for one 767 AD modification Boeing actually didn't give out wiring routing diagram because it would just cause endless nightmare...
 
User avatar
CrewBunk
Posts: 316
Joined: Sat Nov 18, 2017 3:12 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sun Oct 03, 2021 2:24 pm

celestar345 wrote:
The problem with 767 is that with so much variations and configurations you won't know what aircraft would have some special capabilities...

I still remember for one 767 AD modification Boeing actually didn't give out wiring routing diagram because it would just cause endless nightmare...

That’s a good point.

The first batch of our 767-200s were non ER. As they did not have HMGs installed, I understand they never could be ERs. Later 767-200s (still non-ERs), were built from the factory plumbed and wired for an ER conversion and eventually were.

But those first 767s were relegated to domestic only flying. If I understand comments from some of the experts on here, it was impossible to convert them.
 
User avatar
fr8mech
Posts: 8392
Joined: Mon Sep 26, 2005 9:00 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sun Oct 03, 2021 3:05 pm

CrewBunk wrote:
If I understand comments from some of the experts on here, it was impossible to convert them.


Oh, I wouldn’t say impossible. I’d say way too cost prohibitive to even consider it.
 
User avatar
CrewBunk
Posts: 316
Joined: Sat Nov 18, 2017 3:12 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sun Oct 03, 2021 5:04 pm

fr8mech wrote:
CrewBunk wrote:
If I understand comments from some of the experts on here, it was impossible to convert them.


Oh, I wouldn’t say impossible. I’d say way too cost prohibitive to even consider it.

Well, I supposed you could take the airframe apart, right back to a million separate parts and rebuild it …. at a cost of several times that of a new airframe, but both Boeing and Air Canada Technical Services (that does D Checks on 767s) both said “impossible”. They even said it couldn’t be done during a D Check.

Understand, these are frames designed and built during the early 1980s when Erops Twin flying was a pipe dream at best. They were AC FINs 601-606, plus the two purchased from PWA, 671 and 672. FINs 607 and later were built from the factory with the “possibility” of being an ER, but were not converted till much later.
 
User avatar
fr8mech
Posts: 8392
Joined: Mon Sep 26, 2005 9:00 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sun Oct 03, 2021 6:34 pm

CrewBunk wrote:
fr8mech wrote:
CrewBunk wrote:
If I understand comments from some of the experts on here, it was impossible to convert them.


Oh, I wouldn’t say impossible. I’d say way too cost prohibitive to even consider it.

Well, I supposed you could take the airframe apart, right back to a million separate parts and rebuild it …. at a cost of several times that of a new airframe, but both Boeing and Air Canada Technical Services (that does D Checks on 767s) both said “impossible”. They even said it couldn’t be done during a D Check.


I’m not going to argue the semantics of “impossible” and “cost-prohibitive”, but you can certainly install new an HMG, the associated plumbing, valves and control circuitry, plus redo the electrical architecture of the aircraft to accommodate an installation that meets the intent of an HMG and and it’s associated wiring. The components may not be in the same place, and the overall weight and complexity may be higher, but I’m sure it can be done. But, why would you?
 
User avatar
CrewBunk
Posts: 316
Joined: Sat Nov 18, 2017 3:12 am

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sun Oct 03, 2021 7:17 pm

Well it raised a very interesting discussion on another thread. I asked the question of what is it about those early build 767s that made it “impossible”. As you may know, we have some very well versed Boeing employees on here and they brought up some interesting points.

One even sent me a cost study of doing such a conversion. I imagine at some point, more than a couple airlines with these early builds were curious.

As I said, it would take bringing the airframe right to bare bones. And, it would have to be exactly as built at the factory as new build ERs. This is important as any variation would require a whole new set of testing and licensing. Almost starting from scratch as both the FAA and Transport Canada are very careful about EROPS operations. (Not to mention Boeing).

The study was done about 15 years ago and the cost was estimated at around $50M including testing and licensing. Then ….. you end up with a -200ER. Not really the ideal airframe for long international operations.

The last configuration AC had was 169 passengers in an FJY cabin. Hard to pay off $50M with so few passengers.

So as you say, it really comes down to semantics. “Impossible”? I suppose anything is possible. “Cost prohibitive” ? Maybe not if profit was neither your aim nor goal.
 
bigb
Posts: 1513
Joined: Fri Nov 07, 2003 4:30 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Tue Oct 05, 2021 9:22 am

CRJs have them to provide limited electrical power. The 747-8s have them to power Hydraulic System 3 only.
 
celestar345
Posts: 78
Joined: Wed May 08, 2013 5:35 pm

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Sat Oct 16, 2021 2:46 am

fr8mech wrote:
CrewBunk wrote:
fr8mech wrote:

Oh, I wouldn’t say impossible. I’d say way too cost prohibitive to even consider it.

Well, I supposed you could take the airframe apart, right back to a million separate parts and rebuild it …. at a cost of several times that of a new airframe, but both Boeing and Air Canada Technical Services (that does D Checks on 767s) both said “impossible”. They even said it couldn’t be done during a D Check.


I’m not going to argue the semantics of “impossible” and “cost-prohibitive”, but you can certainly install new an HMG, the associated plumbing, valves and control circuitry, plus redo the electrical architecture of the aircraft to accommodate an installation that meets the intent of an HMG and and it’s associated wiring. The components may not be in the same place, and the overall weight and complexity may be higher, but I’m sure it can be done. But, why would you?


If you have too much money and nowhere to spend, yes it's definitely doable - I am sure Boeing will be more than happy to take on a project and give you a totally rip off price tag!

A good example is what Collins did to the KC-46 tanker, definitely doable to the mainline 767 but whether it's worth the expense is another story.

Who is online

Users browsing this forum: tmu101 and 14 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos