A Raven II will easily do 110kts especially if you push through the bow wave and hold it there steady i.e. level off within 5 minutes on take-off rating and allow A/C accelerate, then gently reduce power to max cont - you'll find she'll cruise a tad faster (extra 5-10kts) but the trick is to hold her steady otherwise you'll lose the advantage as the bow wave builds back up. I was was introduced to the technique by a fixed wing bod.

On my own (I'm only a lightweight) I can get 115-120kts cruise out of a good clean Raven II.

As for APS - 1520lb is about right for Raven IIs with night kit, 1460lb for Raven I and Astros.

'Bump' in flight
 

We have had a bump/bang reported on an R44 during flight, no associated feedback or vibration felt through airframe or controls, no evidence of birdstrike, extensive engineering checks revealed no abnormalities with the aircraft, the freewheel checks iaw R44 SL-33 check out fine on rundown, also during auto's & recovery.

The aircraft is used in a training environment, so the freewheel is 'exercised' more frequently than during normal use.

We can reproduce a similar sound by flexing the side panels.

Any thoughts?

:confused:

I've heard the two rear removable panels bang occasionally (cooling down on a hot day) but not sure you would hear it in flight?? Also maybe the fuel tank if the cap was tight and loosened up a bit allowing pressure out?

Bumps and Bangz and quite different things - which was it? :confused:

Bump/bang
 

A noise without any associated vibration or feedback through airframe or controls.

My 44 occasionally makes a noise during the transition as one of the panels "pops" due to pressure differentials. Only ever does it the once and never in the transition back to the hover.

My friend once had the pilots door on his R44 pop in flight, and although it seemed closed at the latch beside the handle, he discovered the latch at the top of the door was outside the door frame when he landed. He hadn't realised the door latched at the top also. Closed normally on the ground and never happened again, just a thought.
R

Bondu121


And you have already read / considered posts 1229 onward (see last page)?

A "bump" like a bird strike (no bird) with no loss of power or vibration was exactly what this felt like in the early stages. Did not show up in the run-down freewheel checks and only when the sprag clutch was removed and tested was it found.

John

44
 

You mentioned that your machine is used for training, if in the previous lesson the guy has been doing some run on landings, this usually leads to the side panels getting a bit distorted, seen by the bowing of the panels between the screws.

Could have been the panels springing back in to shape once in the air.

PB

Misterbonkers,
Refer to page 2-1 in your POH. If you are using the five minute take-off rating to accelerate over 100 KIAS, you are exceeding a limitation.
"Do not exceed 100 KIAS when operating at power above MCP."

Also refer to SN-37, at the bottom of the page.
"The most damaging conditions occur when flying or maneuvering at high airspeeds combined with high power settings."

Power setting
 

R44guy

fully agree on limitations. Imho such power settings are also not really usefull.


Misterbonkers

A well tuned R44-II should achieve those speeds well below max continuous. I don't know about bow-waves etc other than with boats that sail on a boundary surface between two media, but I would call it fine tuning.


My personal experience and my computer models show that 2 POB gives a higher max speed than 1 POB. A possible explanation is that if it is too light, drag may be bigger because of a more forward tilt of rotor disk, thus higher induction. Any body with similar experiences/thoughts on that paradox ?

d3

Sprag clutch
 

The sprag clutch was in several parts when investigated, very worrying that all the recommended checks do not show up a failing clutch.

When removed from the aircraft the sprag felt a little rough, when dismantled it was obviously not far off complete failure.

A new design clutch is now in use - C188-3 Rev H.

Be wary of writing off bangs in flight as panel flexing.

MOR raised & RHC notified.

How many sprag clutch failures are needed before CAA (etc) get interested?

After 25 years and 14 Robinson aircraft I would like to make a couple of observations, limited to the R44
Most cost effective helicopter available, as long as you sell before the 2200hr
Only helicopter I know that if you U/S one blade you have to do both
In the highest speed to lowest fuel burn ratio they are tops
Safe within limitations
The only aircraft I know of with in built recurring corrosion problems
Robinson should at least offer them without paint so the buyer can get a decent job done, including undercoat.
A pleasant aircraft to fly, maintain and store, no fuss operation with great dependability.

Robinson Paint
 

Do Robinson supply touch up kits for their machines. Just had mine back from its annual and would like to touch up all the screw heads etc to make it look presentable again.

Thanks

Dont think so VG, if you ask your maint. outfit they may have the right colour Robbo paint (and activator) that they can let you have a small jar of. Depending on how big they are they may not though because its expensive (not so much the paint, getting it here).

Failing that with new machines there is/should be a bag of spare screws that could be used if no paint is available. It should be in the RHC under seat bag with all the other goodies they give you.

tha's right, right along with that good ol' US of A quarter they give you that you do the tap test with

good luck ha ha.
tet

If you have painted fuel caps take one off and head down to a paint shop and they can make up a small can for you. We used to do that and it worked really well on small areas like screw heads.

TiP;)

Any advice on how to prepare an R44 for a 3 months 'wintersleep'? It's kept in an isolated hangar, but temperatures of -20 C are possible.
Thanks in advance,
FTF

Probably a good idea to take the battery out and put it somewhere warm. Can you run a dehumidifier in the hanger?

The IO540 manual from Lycoming has some specific advice (from memory), including removing the plugs to squirt in some kind of corrosion inhibitor.

Robinson customer service would, I'm sure, provide some advice too.

I would personally prefer going to the trouble of turning it over at least once a month and ground/hover running to keep all the seals well lubricated. Then the hassle of protecting the cylinders is unnecessary.

Lafite