Comments on: Mast rocking

By: S Miller

S Miller — Thu, 23 Feb 2012 19:47:10 +0000

Why is the mast SO high in the first place?,….have a look back to the late 40′s and early 50′s and you will see that the greats of aeronautical design and funding had exhausted and tested many of these theories before,( Notably the Russians, French, Americans, British and Italians)…..with HUGE financial backing, intelligence and hindsight…..why have most of the exsisting designs come up with the short mast versus horsepower….especially with the development of the gas turbine…..

By: S Miller

S Miller — Thu, 23 Feb 2012 19:27:01 +0000

I am Australian, and we have had several Robinson fatal accidents before, and I believe that many of them are just simply NOT pilot error….some of these pilots were experienced NZ and Aussie helicopter pilots that have flown other types without incident.

By: S Miller

S Miller — Thu, 23 Feb 2012 19:23:22 +0000

All I can say is this…..how many modern, commercial, successful and proven helicopter designs have such an extensive and TALL mast for the main rotors on their copters, I think nil…..Bell, Aerospatiele, Sikorksy ( The BIG russian giants ), ALL of their rotor masts are short comparitevely……come on,…I am a fixed wing pilot, 44 years old and have been an enthusiast of aviation for most of my life and even though I am NOT a helicopter specialist, even I can see and appreciate the shortcomings of this design.( And yes, I have flown in helicopters before ). It is SIMPLE maths and physics….so much mass spinning around creates a huge centrifical force, the shorter the central locating shaft, the less movement and vibration no matter HOW you try to change it.

By: Dangerous Flying: Abrupt Control Inputs | An Eclectic Mind

Dangerous Flying: Abrupt Control Inputs | An Eclectic Mind — Tue, 31 Jan 2012 15:26:54 +0000

[...] January 31, 2012 note: Since writing this, a friend on the Rotorspace site has brought the topic of Mast Rocking to my attention. Apparently, some folks think that this accident may have been caused by Mast [...]

By: Maria

Maria — Tue, 31 Jan 2012 14:28:06 +0000

I’d heard rumors about something called Mast Rocking in R44s but hadn’t really looked into it until someone pointed me (indirectly) this post. Oddly, just yesterday I was flying with this kind of profile: a bit heavy, forward CG, and 90-100 knots. I definitely noticed more vibration in the rotor system than usual. Certainly not enough to set down, but now it’s got me wondering if it had anything to do with this.

As an owner, I fear ADs because of the costs involved. The recent Robinson fuel bladder SB will cost me about $12K to comply with; an AD that affects the transmission mount or anything under the hood could cost far more than that and will be REQUIRED. I’d much rather see a change in the CG envelope and recommendations for avoidance coupled with a new design that can be implemented at overhaul.

Also, if my memory serves me right, when I flew Long Rangers at the Grand Canyon (back in 2004), a hard set down on the pad would often cause a thump-thump-thump of the main rotor system. We called that chugging. I’m wondering if its somehow related. No issues in flight though; Long Rangers with 4-7 on board fly remarkably level no matter how you load them.

By: Les

Les — Sat, 12 Nov 2011 19:25:16 +0000

As an operator of an R22 and R44 this is great infomation.

Is the FAA just going to wait until there are more reports and or fatal accidents of mast rocking until they have an AD.

I agree with the comments posted that if the aircraft is operated within the limits of the POH you SHOULD NOT have to worry about killing yourself.

Come on Robinson, fix this

Totally ridiculous.

By: Jim Borger

Jim Borger — Mon, 07 Nov 2011 00:45:56 +0000

“No aircraft will do everything well” Compared to what? All aircraft have certain limitations and some do certain things better than others. As long as an aircraft is operated within the limitations in the RFM or POH you shouldn’t have to worry about it trying to kill you or/and itself.

By: Steve R

Steve R — Sun, 06 Nov 2011 18:58:11 +0000

Aircraft of all types have short comings that may require special attention by the operator, (the Bell tail-rotor is prone to LTE, any Cessna single can loose elevator authority while slipping with full flaps). This is why insurance companies require training and time in type. If you want a fool-proof aircraft, stay in the simulator. The R44 is a great machine when used properly, no aircraft will ever do everything well, learn your limitations, the limitations of your equipment, and act accordingly.

By: Drew Clark

Drew Clark — Sun, 06 Nov 2011 01:29:22 +0000

Russ,

The NTSB is charged with investigating accidents and delivering probable causes and recomendations only. They have no power to enact legislation or force anyone to do anything.
It’s up to the FAA to take the recommendations and decide to pursue a course of action (such as an AD). Of course, the FAA has to open a comment period (Notice of Proposed Rule Making) before any AD becomes effective.

By: grumpy

grumpy — Sat, 05 Nov 2011 18:11:13 +0000

Seems like Robinson, along with Cirrus, are AOPAs’ “golden boys”.