Report from the BBC:

BBC NEWS | England | Safety scare grounds helicopters


"A number of police and air ambulance helicopters have been grounded while maintenance checks are carried out.
It follows an incident involving the London Air Ambulance at Denham Airfield, in Oxfordshire.
A rotor tail fault, which can cause a sudden drop in height, is understood to be the cause of the scare"

MD902 "Rotor Tail Fault"
 

"A rotor tail fault, which can cause a sudden drop in height, is understood to be the cause of the scare." Quote of the week from the BBC News website I feel!!

As I've not got much experience of helicopters, can someone explain to me:

1, What is a rotor tail? (I expect that they mean tail rotor) - see next point.
2,If the MD902 is NOTAR, where's the rotor tail?
3, How does "a rotor tail fault" cause a sudden loss of height?

Ah bless the BBC, they're the envy of the rest of the world you know! Pah!!

Tail rotor faults can cause death and destruction. I would take a "sudden drop in height" any day.

Well the lady tv reporter did say NOTAR and did say that meant it didn't have a conventional tail rotor so would somebody kindly enlighten us as to what the suspected fault with these grounded aircraft may be, please?

Perhaps connected to the fan that blows air down the tail boom, similar to the Austrian MD902 incident?

Or just a rumour...

MS

The vertical stabilizer control system (VSCS) actuator rod was rumored as the cause of last month's CALSTAR MD902 accident.

I/C

NOTAR - well not that you can see anyway. Still has one but NOT At Rear? Must be a middle or back rotor or something. I still don't get it unfortunately.

RVDT - there is no tail rotor! Read this and look at this.

I believe that it was a part of the linkage between the pedals and the thruster that failed.

There is SBs on the linkages already, TT straps & rotating cone cable\rod

http://www.mdhelicopters.com/publica...2006-18-01.pdf

http://www.mdhelicopters.com/publica...004-23-15c.pdf

Glad no one hurt, BBC report really mixed up said ship returned to base, good show the crew

We live approx 1 mile N of Denham and there was what sounded like a NOTAR helicopter hovering and then circling quite low at approx 22.00 on Sunday night...thought it maybe police but then saw this...anyone know what time the incident happened?

The area of concern was a frayed control cable according to BBC local news in Leeds.

Both Yorkshire Air Ambulances (and presumably the West Yorkshire Police helicopter) have been flown to MD's maintenance base for checks.

Extension ?
 

The fleet of MD902's all had a "Free of charge" tail boom extension over the last couple of years didn't they ?

AFAIK this was required to give extra thrust at the end of the tail boom to cater for an increase in power.

Presumably, as well as extending the tail boom itself by splicing in a new section, all the control gear would have had to be extended too wouldn't it ?

I wonder if it is the control gear extension that has failed :rolleyes:

( Don't think it will have anything to do with a dodgy fan belt like the BBC says - if so perhaps it could be fixed with a pair of my better half's old tights :oh: )

http://i34.photobucket.com/albums/d1.../Coconutty.jpg

I beleive that Coconutty's theory is pretty much bang on...

MDHI website has the SB. (under publications, directives, 900sb ) dated 12 Aug 08.

Air Ambulance
 

Incident? Yes there was one

Complete speculation: If directional control were lost or impared, the pilot would reduce collective, and the result would by a "sudden drop of height"?

Bus429,

Sorry was being sarcastic. I was probably the second 600N operator on the planet after the one in SA.

There IS a tail rotor its just been moved somewhere else. :ugh:

In case anyone else is finding it difficult to find it's at:

http://www.mdhelicopters.com/publica...s/sb900108.pdf

on page MD Helicopters - American Pride Rising to New Heights

Its a "tail rotor" in the same sense as the "Wives' Coffee Mornings", held at the SAR training unit (Anglesey UK), were actually coffee mornings.


(ie no coffee, not in the morning, no wives)