V-22 engine replacement RFI sent out.

In February, Rolls Royce was awarded a $90.1M contract modification for AE 1170C engines for the Marine Corps V-22 aircraft. It called for an additional 22 engines, in addition to the 40 already on order. Rolls Royce has recently increased the power of the engine by 17%, and in April received a $39M contract to maintain those engines in Indianapolis, Oakland, and at various military bases.

Now, NAVAIR has sent out an RFI looking for a drop in replacement for V-22 engines, that will fit the existing structure, with minimal modification, and support all versions of the V-22. Requirements are for no less than 6100 shp, at 15,000 rpm, with operations at 25,000 feet up to 130 degrees air temperature.

The US military has put out a call for drop-in replacement engines to power all variants of its Bell-Boeing V-22 Osprey tiltrotor aircraft.

A request for information (RFI) released on 26 August seeks information from industry “on alternative power plant solutions capable of powering all MV/CV-22 (all models) Osprey as well as any foreign military sales aircraft in a safe, reliable, cost-effective and sustainable manner which demonstrate a best value to the government.”

Navy Air Systems Command (NAVAIR) is leading the effort to identify potential replacements for the Rolls-Royce AE-1107C engines that power all V-22s operated by the Marine Corps and US Air Force, according to the solicitation. The solicitation does not specifically mention the Rolls-Royce engine.

www.flightglobal.com...

a reply to: Zaphod58

Cool. Do you know if the increased hp will give the V-22 increased airspeed or payload capacity? I image there are airframe limits to these.

a reply to: Sammamishman

Might not see much increase in speed, but you'll see an increase in payload (which is why you won't see much increase in speed). As well as being able to operate in hotter areas.

Off topic a couple of v-22s and a c-130J have been at RAF fairford over the last few days. The rumour mill has also been working well as Air Force 1 may be due there in a few weeks

originally posted by: Sammamishman
a reply to: Zaphod58

Cool. Do you know if the increased hp will give the V-22 increased airspeed or payload capacity? I image there are airframe limits to these.

With a 17% power increase the airspeed is not effected that much. Where the increased HP is important is in the hovering in ground effect (HIGE) and hovering out of ground effect (HOGE) performance. It allows the aircraft to operate at higher altitudes and to pick up heavier loads at higher altitudes. I'm guessing that the airspeed increase will be around 20 MPH and the additional 200 HP will lift an additional 1000 lbs.

Rolls Royce has proven that an improved AE 1107C engine used in the V-22 can operate in the high altitude and head of Afghanistan. The engine was able to propel a V-22 to 6,000 feet in 95 degree temperatures. Engineers developed an improved and more efficient set of blades and turbine parts.

www.flightglobal.com...

Obviously I'm no aeronautical engineer as the following idea proves.

Why not try slapping on a pair of engines from the A-10? Since they're retiring the A-10 fleet and if it worked, there would be a crap load of parts already available from Davis-Montham.

Just a idea. And you have to admit...it would look pretty cool as well.

Never mind...I see my idea was asked a loooong time ago.

sg.answers.yahoo.com...

a reply to: TDawgRex

Turbofans don't do well with all the dirt and dust kicked up trying to land. Turboprops do better with that.

a reply to: Zaphod58

The reply in Yahoo Answers looks like something that you would have posted if you had the time. Very informative.

originally posted by: Zaphod58
Rolls Royce has proven that an improved AE 1107C engine used in the V-22 can operate in the high altitude and head of Afghanistan. The engine was able to propel a V-22 to 6,000 feet in 95 degree temperatures. Engineers developed an improved and more efficient set of blades and turbine parts.

www.flightglobal.com...

Zaph, I think that the 6000 ft. altitude refers to the ability to hover at that height at 95 degrees. This is an important feature for operations in places like Afghanistan with many mountainous areas. If the CV-22 can't hover at that height it has to make a running landing so much more space is needed to operate. It will also restrict the amount of load that can be carried. The Chinook has the same issues with ops at high altitude LZs in Afghanistan.

a reply to: buddah6

That's exactly what it was referring to, the ability for helicopter ops at high altitude.

The aircraft rotor sytem - gearbox, rotor hub, blades - can't transmit more power at ground level unless they are redesigned. The rotor diameter is limited to fit on an aircraft carrier. Increasing engine power by running the turbine hotter does allow improved hover performance at altitude, up to the point the aircraft rotor blades are running at their max allowable pitch angle. Engine sfc, fuel burn rate, will not be ideal at altitude, as ideally the compressor pressure ratio needs to be increased at the same time the turbine is run hotter.
What is interesting is that the GE38, going on the CH-53K, probably has a better match of pressure ratio to turbine inlet temperature. en.wikipedia.org...
So if Rolls-Royce wants to retain the business, they probably will have to design a new compressor with higher pressure ratio. Which also means a redesign of the combustor. This costs big money and time.
What is even more interesting, the Army is funding all new engine technology in the 3000 hp range -en.wikipedia.org...
but I am not aware of an all new core being developed in the 7000 shaft hp range. Which is what the Osprey would really benefit from.

a reply to: Matt1951
Matt, Another way to improve the performance is to change the rotor airfoil. If the diameter is fixed, as in this case, an improved airfoil and increased washout (twist) will be about the only way to increase performance with the rotor if the hub isn't redesigned.

You are correct about the engine and gearbox torque limitation with higher HP engines. The only way to use the existing transmissions and cross shaft gearboxes is to limit time and temperature of the components to short time intervals.

I've read that the CH 53 is going to be the "go to" heavy lift aircraft over the Osprey due to the expense of hourly operation. Also the H 53 has a higher availability than the V 22.