Chinese AG600 amphibian complete maiden flight

[Lyneham Lad]

On Aviation Analysis Wing (http://www.aviationanalysis.net/2017/12/chinese-ag600-amphibian-complete-maiden-flight.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+AviationAnalysisWing+%28Aviation+Analys is+Wing%29)

Snip:-
The AVIC AG600 amphibious aircraft has completed maiden flight from the Zhuhai airport in Guangzhou, China on Sunday.

The AG600 is the first amphibious aircraft developed in China and currently the largest of the type in the world.

The aircraft can takeoff/land from sea or land and is designed for fire fighting and marine rescue missions. It is equipped with floats on either wings for stability while operating in sea.

The AG600 features a single hull, cantilever monoplane layout equipped with retractable, tricycle-type landing gear and is powered by four domestically manufactured WJ-6 turboprop engines.

With a maximum take off weight of 53.5 tons, the aircraft is 37 meters long, 12.1 meters high, and has a wingspan of 38.8 meters.

Probably to be seen visiting the Paracels & Spratlys areas in the not too distant future...

[Less Hair]

Reefs please. They are not elevated permanently above mean sea level and located in international waters.

[atakacs]

On Aviation Analysis Wing (http://www.aviationanalysis.net/2017/12/chinese-ag600-amphibian-complete-maiden-flight.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+AviationAnalysisWing+%28Aviation+Analys is+Wing%29)

Snip:-


Probably to be seen visiting the Paracels & Spratlys areas in the not too distant future...

An interesting design in this day and age... I'm sure the intended use goes further than SAR / firefighting

[MrBernoulli]

It vaguely resembles the Russian Beriev Be-200, except that the Beriev has two over-wing jet engines, of course, but there is much familiarity in the appearance of the fuselage.

[Pontius Navigator]

Well, they say if it looks right . .

I reckon that's a goer.

[surely not]

Looks very similar to the Japanese Shin Meiwa US-2 flying boat.

[Mechta]

Looks very similar to the Japanese Shin Meiwa US-2 flying boat.

But doesn't have the fifth engine for blown flaps, which gives the US-2 an impressively short off (starts at 1:10):

FLm6hTwDx-k

[Trim Stab]

Where is the flap blowing compressor situated on the airframe?

Also, the US-2 has a shorter take-off run on water (280m) than on land (490m) - can the compressor only be used on water take off? Also, intrigued to know why so much water continues to pour out of the airframe after lift-off. Does it perhaps use water-ballast while the hull is in displacement mode, then gradually expel ballast as the airframe starts to provide lift and directional stability?

Edit: I found on the ShinWeya website that the blower compressor is dorsally mounted and controls boundary layer on not only lifting surfaces but also on elevator and rudder, which explains why it can have such a low stall speed and Vmca. Some of the impressive amount of water flowing from the airframe after lift-off might be from the anti-spray skirt, but I still suspect there might be some water-ballasting. I suspect that this might also explain why TODR is substantially shorter on water than on land. Probably VMCg/VMCw is the limiting factor on take-off (since VSO1 and Vr are incredibly low) and VMCg>>VMCw. VMCw could be made very low (and much less than VmCg) if the hull had some displacement ballast until above VMCa. Must be a fabulous job to be a TP for a company like that!

Another edit: I watched a few youtube videos of other large seaplanes taking off such as Martian Mars, CL415 and BE200 and it is quite noticeable how late they "rotate", as if they are staying on the water for as long as possible in order to accelerate beyond VMCw and VMCa (particularly noticeable on BE200).

[George K Lee]

Maybe the land T/O is a runway length including a rejected T/O?

Or possibly they just didn't test that bit of the envelope because there aren't any runways shorter than that, and the landing gear won't do anything off-runway.

I have never heard of ballast, which would slow you down a lot. I think we're seeing a lot of water, but not tons, being transformed to spray as it drains out of the suppressor groove.

The interesting historical bit is that the blow-everything-with-a-separate-compressor concept was apparently borrowed from the US Navy in the 1950s. The navy wanted to hunt nuclear subs with a 'boat that could land in the open ocean and dip a sonar. Convair and Martin both designed aircraft but neither was built, and the original ShinMaywa PS-1 had a sonar.

[TEEEJ]

The Chinese Navy still operate a small number of Harbin SH-5s.

http://www.fliegerweb.com/data/LexikonPictures/HarbinSH5_Intro_640.jpg

https://en.wikipedia.org/wiki/Harbin_SH-5

[Mechta]

Also, intrigued to know why so much water continues to pour out of the airframe after lift-off. Does it perhaps use water-ballast while the hull is in displacement mode, then gradually expel ballast as the airframe starts to provide lift and directional stability?

The water could be that which collected in the undercarriage bays. With the doors shut it would take a while for them to empty.

[etudiant]

The interesting historical bit is that the blow-everything-with-a-separate-compressor concept was apparently borrowed from the US Navy in the 1950s. The navy wanted to hunt nuclear subs with a 'boat that could land in the open ocean and dip a sonar. Convair and Martin both designed aircraft but neither was built, and the original ShinMaywa PS-1 had a sonar.

In WW2, Germany built the Henschel 130, a high altitude recon aircraft using a third engine to power the supercharger for the two main engines, but it did not become operational.

[Trim Stab]

Maybe the land T/O is a runway length including a rejected T/O?

Or possibly they just didn't test that bit of the envelope because there aren't any runways shorter than that, and the landing gear won't do anything off-runway.

I have never heard of ballast, which would slow you down a lot. I think we're seeing a lot of water, but not tons, being transformed to spray as it drains out of the suppressor groove.

The interesting historical bit is that the blow-everything-with-a-separate-compressor concept was apparently borrowed from the US Navy in the 1950s. The navy wanted to hunt nuclear subs with a 'boat that could land in the open ocean and dip a sonar. Convair and Martin both designed aircraft but neither was built, and the original ShinMaywa PS-1 had a sonar.

It might also just be a limitation in case of compressor failure on t/off. The airframe would immediately stall should the compressor fail just after rotation - fairly catastrophic over land but maybe acceptable over water.

Big drawback of amphibians for maritime surveillance is where do you put the sensors? Can't see any EO/IR turret, or marine radar on US-2

[Just This Once...]

Should the compressor fail the engines would still provide a blown wing, reducing the stall speed to a safe level.

The compressor provides low-speed rudder/fin effectiveness, so a failure at very low speed off a normal runway could be dramatic. In the water the hull provides additional yaw stability and when transitioning from the step to fully airborne you have considerably more ‘runway’ width available if it all goes wrong.

[sandiego89]

......Big drawback of amphibians for maritime surveillance is where do you put the sensors? Can't see any EO/IR turret, or marine radar on US-2.....


But the US-2 is really not a full spectrum MPA aircraft- it is really a SAR/utility aircraft, and seems to be well suited for that role. It does have a nose mounted radar.


I would think fitting other sensors would be a fairly straightforward fit, and other than avoiding belly mounted sensors, there would be plenty of other locations to fit a FLIR etc. Remember her earlier cousin, the PS-1 had search radar, dipping sonar, sonobuoys, searchlight, weapons, MAD etc...


As for comments on the excess spray under the aircraft the PS-1/US-1/US-2 was fitted with a water spray system where water was pumped along the fuselage to reduce sea spray- effectively a water stream to deflect the sea spray from coming up.