25
votes
Accepted
How does the V-22 Osprey share engine power between its rotors?
It is possible to drive the two rotors of the V-22 Osprey from a single engine using a segmented driveshaft connecting both engine shafts via gearboxes:
The drive shaft is depicted in blue in the ...
- 80.8k
21
votes
Accepted
How do the cockpit controls of a tiltrotor aircraft work?
This video explains it nicely starting at about 1:20 in.
Also see here.
This is a pretty interesting article on flying it as well. It really seems to depend on mode but its summarized here nicely,
...
- 102k
18
votes
How does the V-22 Osprey share engine power between its rotors?
Tilt rotors and virtually every other VTOL aircraft with more than one lift rotor (Chinook, K-Max) or proprotor (AW609) must employ a shaft between these lift units, so when one engine is out the ...
18
votes
Accepted
How does a tiltrotor yaw while in vertical flight?
The V22 Osprey yaws by tilting one rotor backwards from the vertical and one forward by moving the swashplate up on one side and down on the other causing a cyclic change to the rotor blade angles of ...
- 31.3k
17
votes
Can a tiltrotor fly safely with one engine?
Short Answer: yes. If they could not, they'd likely not get certified
One engine can drive both prop rotors.
After digging into an old version of the V-22 flight manual, I find a whole pile of tables ...
- 4,211
14
votes
Accepted
Can a tiltrotor fly safely with one engine?
This concern was one of the major design challenges in the development of tilt-rotor VTOL craft. In every flying example I'm aware of, it was solved one of two ways: either the engines were embedded ...
- 17.3k
13
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How do VTOL aircraft like the V-22 Osprey not tilt?
If you think about it, your question applies in exactly the same way to a conventional helicopter. You might expect that it would pitch nose-down if the weight is forward, and nose-up if the weight is ...
- 12.7k
10
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Why does this V-22's rotors rotate clockwise and anti-clockwise (the right and the left rotor respectively)?
A couple of things.
One, I suspect the reason is similar to why the arrangement is also used on the P-38 Lightning airplane from World War II. The counterrotating engines on that airplane originally ...
- 75k
7
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Do ducted fans have a future in forward flight aircraft? Can they be made more efficient than open rotors?
Fan shrouds are a fix for a problem that can normally be designed around in other, more efficient ways. They do reduce tip loses, but usually the tip loses are smaller than the weight and drag penalty ...
- 3,433
7
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Could a tilt quadcopter use turbofan engines?
In a way, this has been done already half a century ago.
When NATO decided to try a VTOL strategy, the Harrier was not the only result. There was even a supersonic VTOL fighter, and it used ...
- 237k
6
votes
Why does the NASA GL-10 Greased Lightning run on diesel?
There is a bit of a misnomer here, although the plane runs diesel engines it most likely does not run traditional diesel fuel as you would find at a gas station. Diesel engines can be run on Jet-A ...
- 102k
6
votes
Accepted
Does the Osprey have a "worse" downwash than a helicopter of equal weight?
higher disk loading... means a more concentrated downwash
Correct and this can be demonstrated even using a very simplified approach like the momentum theory by which the airspeed $w$ under a rotor ...
- 15.8k
5
votes
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what are the advantages and disadvantages of tilt rotor vs ducted jet engine for a VTOL aircraft?
Well, engines and rotors obey the same laws regarding induced drag (induced power in this case) as wings: larger fan/propeller/rotor is more efficient, but limited to lower speeds. And from that, the ...
- 56.5k
5
votes
How much do the blades on the V22 or AW609 weigh?
" However, two Osprey 38-foot rotors weigh 4,654 lbs (JANE's, 1998-9, p. 557.)" this quote is from http://www.freepatentsonline.com/8382030.html
That would put the mass of a single V22 rotor at 1050 ...
- 438
5
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How does the V-22 Osprey share engine power between its rotors?
The cross shaft of the V-22 is normally unloaded. It only takes up the load if an engine fails, at which point everything continues as normal albeit with reduced power. Alternatively, if the shaft ...
- 51
5
votes
Could a tilt quadcopter use turbofan engines?
The main reason V-22 uses propellers is efficiency. To get high thrust for power, you need to affect a lot of air and that requires a large propeller. The V-22 has huge propellers, closer to ...
- 56.5k
5
votes
Would it be beneficial to have rotors AND propellers instead of a tiltrotor?
There are 2 major problems. First is the weight you'd incur from:
Extra rotors/propellers
Transmission components (the V22 already has a transmission in case of an engine failure, it's already more ...
- 54.4k
4
votes
Accepted
How to calculate the power required during transition from VTOL to fixed wing?
Like Hobbes said. For instance, after take-off, tilt the thrust 10° forward. The cosine is 0.98 so you only lose 2% of propulsion lift. The sine is 0.17, so forward thrust is 0.17 * total thrust.
The ...
- 62.9k
4
votes
Accepted
How does the Bell V-280 (a tiltrotor) rotate, bank, and fly sideways?
The yaw would be accomplished by angling one rotor a little forward, and the other a little backwards.
The shifting move to the side is accomplished by generating more thrust on one side. Either by ...
- 1,025
4
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Why does this V-22's rotors rotate clockwise and anti-clockwise (the right and the left rotor respectively)?
I can't really comment on Carlo's answer about interference with the empennage, but one result of the wingtip propellers turning against the tip vortex is that it effectively increases the length of ...
- 642
4
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Does the Osprey have a "worse" downwash than a helicopter of equal weight?
Yes, your reasoning is correct.
- 237k
3
votes
Can a Stewart Platform be used instead of a swash-plate assembly in a helicopter? What are the pros and cons?
The purpose of the swashplate isn't to tilt the rotor head. It's to pitch each blade as it passes through various sectors of the disc.
In a Stewart platform, both plates rotate at the same time. In a ...
- 30.1k
3
votes
Accepted
Would it be beneficial to have rotors AND propellers instead of a tiltrotor?
What you describe is effectively a "compound helicopter" -- an inefficient design used only when you must combine hovering flight with maximum forward speed -- but with hovering managed by ...
- 17.3k
3
votes
How do VTOL aircraft like the V-22 Osprey not tilt?
According to various bits of online documentation, the rotors have cyclic pitch control like a helicopter as well as collective pitch control like a helicopter and most high-performance propeller ...
- 131
2
votes
What is the difference between Tilt-rotor aircraft and Tilt-wing aircraft?
I would say that the complexities of tilting the entire wing are what compelled Bell to choose just the nacelles.
By complexities, I am thinking 2 major systems. The first is the flights controls. ...
- 539
2
votes
Accepted
At which angle tiltrotor's rotors generates more lift?
Technically, if the tilt rotor flies forwards with vertical rotors, the lift is produced by the wings and forward thrust by the rotors. So let's regard the rotor thrust, whether in horizontal or ...
- 62.9k
2
votes
Accepted
What would be the advantages and drawbacks of a single-propeller tiltrotor?
Such an aircraft can't exist.
Helicopters don't work with a single rotor, they need at least two of them to counter torque. There are several popular designs, including conventional, coaxial, ...
- 3,000
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