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39

No it does not, it does not need one, there is a mechanical connection to the flight controls that can be used if all else fails. The B737 flight controls are hydraulically powered. There are three hydraulic systems: System A, System B, and Standby. Only one main system (A or B) is required for hydraulically flying the aircraft, during normal operation they ...


30

The plane in your question is the Saab 37. According to x-plane.org about this plane— Emergency power is supplied by a ram air turbine just before the left wing leading edge, which extends automatically on hydraulic power failure, and just before touch down. (Earlier, it was also always deployed whenever the landing gear was down.) They cite Air Power ...


28

The full NTSB report can be found here and is the official source of information on the incident. According to that report Sullunberger did immediately start the APU which did deliver power and they determined they did not need to manually deploy the RAT. However the onboard systems deployed it automatically likely as a result of the initial power loss and ...


18

Is there a maximum airspeed to deploy a ram air turbine? The ram air turbine (RAT) can be extended and used at any speed above a minimum speed, because under this minimum speed, power is difficult to generate. Generated power may be decreased below 130 knots, and extension is prevented below 100 knots because of additional drag produced for nearly no ...


9

According to the Flight Crew Operations Manual of the Boeing 777: Hydraulics The RAT, when deployed, provides hydraulic power only to the primary flight control components connected to the center hydraulic system. Which leaves out: Nose gear Main gear Steering Brakes Flaps Thrust reversers Electric The RAT powers both C1 TRU and C2 TRU, which powers the ...


9

Ram Air Turbines have variable pitch which is set according to demanded load and airspeed, and the controller keeps the rotational speed as high as possible for maximum efficiency. Typical operational RPM of a RAT is between 5500 and 7700 rpm, at speeds between 125 - 375 knots. Let's take the averages: 6600 RPM @ 250 knots = 700 rad/s @ 130 m/s. At a disk ...


7

Even the very first aircraft that were retrofitted with electric instruments had air-driven generators (and Venturi tubes for gyroscopic instruments). Engine-driven generators and vacuum pumps came later. Here's an account of the first non-stop transatlantic flight in June 1919, which suggests air-driven generators were pretty much standard by then. From ...


7

So far, the oldest I have found is LZ-127 Graf Zeppelin, first flight in 1928. It used a propeller-driven generator to power its radios and a second one (with buffer battery) to keep the ship illuminated. In the drawing below (source) they are indicated as "Wind-Dynamo", being on both sides of the main gondola. I am rather sure that the wartime Zeppelins ...


7

Since he doesn't manage to make it back to the runway from his 2000 ft engine flameout run I was wondering if not deploying the RAT would make any difference due to reduced drag? No, because it deploys automatically. Note that in the video in the first attempt the step is not done because there is less time. It is probably included in the checklist just in ...


6

On the 737, the APU is typically started from battery power; this is normally done on the ground, but it could be started this way in flight as well. (The 737 doesn't have a RAT.) The APU is typically operated only on the ground for short-haul flights, although there are cases such as a generator that failed in flight when it's started & used in the ...


6

There is a pushbutton on the overhead panel in the hydraulics section to manually deploy the RAT: 5 RAT MAN ON pb The flight crew may extend the RAT at any time by pressing the RAT MAN ON pushbutton. Note: The RAT extends automatically if AC BUS 1 and AC BUS 2 are lost. (refer to 1.24.20). (A320 FCOM - Hydraulics - Controls and Indicators) There is another ...


5

You have kind of answered your own question. The down side to ram air turbines is they cause drag. The up side is that they provide power outside the internal generating capacity of the aircraft (e.g., in emergencies when there is no power). In the case a of a jamming pod, having its own power source eliminates/reduces the need to rely on internal power. ...


4

A RAT is never an optional piece of equipment. It is only there because the design of the aircraft systems require it in order for the aircraft to meet airworthiness certification.


4

The reason why the RAT deployed is of primary concern. The RAT should automatically deploy when (depending on the design of the aircraft) you lose all primary electrical and/or hydraulic power. In these cases, an immediate diversion is necessary because you may be one failure away from losing control of the airplane. However there are uncommanded RAT ...


4

The RAT only delivers 5 kVA on the A320. It supplies electrical power only to the essential buses. Therefore the APU is still required to power the normal AC BUS bars and the DC buses via TRU's.


3

Before he decided to start the APU which needs power for the starter and some time to spool up and go online he was already on RAT provided power. As stated above if you loose both generators the RAT will deploy automatically in order to provide power to the busses. APU and its generator is just a good backup in case the RAT would fail. This one btw does not ...


3

I made a comment on TomMcW's answer, but I think it deserves to be an answer: I think the answer lies in your question: The EA-6B, which the Growler replaced, was also a modified attack aircraft using jamming pods with ram air turbines. Emphasis and links mine If they were designing an electronic warfare aircraft from scratch, I'm sure that all the ...


2

The B-737 does not have a RAT.


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