Approved single engine in IMC?
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Joined: Feb 2001
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From: Europe
Approved single engine in IMC?
There has been much discussion about legality and safety of single engine over congested areas on another thread, but what about single engine IMC? In the UK flight in IMC is strictly IFR approved twin territory (as far as I know, Bristow's 206 trainer excepted) but what is the situation elsewhere in the world?
Joined: Mar 2002
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From: Iceland
The twin IFR requirement in Europe is an JAR-OPS requirement so all commercial passenger operations (public transport) in JAA land is twin if IFR and this of course also includes fixed wing.
However JAR-FCL only specifies a IFR approved helicopter so single engine helicopters can be used for training, just like in the fixed wing world.
But the problem that makes it all so expensive is that the manufacturers have only, until now, got turbine aircraft approved for IFR.
I feel the added risk factor is acceptable for training but a fare paying passenger can not be subject to single engine IFR in my opinion.
However JAR-FCL only specifies a IFR approved helicopter so single engine helicopters can be used for training, just like in the fixed wing world.
But the problem that makes it all so expensive is that the manufacturers have only, until now, got turbine aircraft approved for IFR.
I feel the added risk factor is acceptable for training but a fare paying passenger can not be subject to single engine IFR in my opinion.
Joined: Jul 2001
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From: ...in view of the 'Southern Cross' ...
Mmmmm BOLLOCKS!
1. I dont believe Bristows BH206 trainer is allowed into IMC. It can operate under IFR only (i.e.training) in VMC .... and yes there IS a difference!
2. In Australia you can not go IMC without being IFR (except inadvertantly)... especially 115 nmls out to sea. And to be IFR you MUST be able to remain above LSALT with a powerplant failed. LSALT offshore is 1500' and the B206 will NOT do that even with a "dodgy AFCS"!!!!!
3. Anybody who has any real HELI IFR experience WILL NOT WANT TO FLY S/E IFR (in IMC) in anything other than a REAL twin, ie decent sized engines AFCS with decent OEI performance at the LSALT !
Cheers
1. I dont believe Bristows BH206 trainer is allowed into IMC. It can operate under IFR only (i.e.training) in VMC .... and yes there IS a difference!
2. In Australia you can not go IMC without being IFR (except inadvertantly)... especially 115 nmls out to sea. And to be IFR you MUST be able to remain above LSALT with a powerplant failed. LSALT offshore is 1500' and the B206 will NOT do that even with a "dodgy AFCS"!!!!!
3. Anybody who has any real HELI IFR experience WILL NOT WANT TO FLY S/E IFR (in IMC) in anything other than a REAL twin, ie decent sized engines AFCS with decent OEI performance at the LSALT !
Cheers
Joined: Aug 1999
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From: Gold Coast, Australia
B#llocks?
Spinwing,
I suspect Mr S was trying a tad of sarcasm, but:
1. ISTR spending a bit of time IMC in Bristow's 206 IFR trainer, but that was a long time ago so things may have changed
2. CASR 1988 175A, here gives you the allowable Single Engine IFR rules for Australia:
175A Restriction on I.F.R. flights by single engine aircraft
(1) The pilot in command of a single engine aircraft must not fly the aircraft under the I.F.R. if the flight is not in one of the following operations:
(a) private operations;
(b) aerial work operations;
(c) charter operations that do not involve the carrying of passengers for hire or reward;
(d) charter or regular public transport operations that involve the carrying of passengers for hire or reward, if:
(i) the operator is approved in writing by CASA to conduct the operations; and
(ii) the operations are conducted in a turbine powered aeroplane approved in writing by CASA for those operations.
Penalty: 25 penalty units.
(2) CASA may issue directions to an operator to ensure that any of the following matters do not affect the safety of a regular public transport operation to which paragraph (1) (d) refers:
(a) seasonal influences;
(b) the conduct of operations by night;
(c) adverse weather patterns;
(d) the terrain below, or in the proximity of, the route used in the operation.
I suspect Mr S was trying a tad of sarcasm, but:
1. ISTR spending a bit of time IMC in Bristow's 206 IFR trainer, but that was a long time ago so things may have changed
2. CASR 1988 175A, here gives you the allowable Single Engine IFR rules for Australia:
175A Restriction on I.F.R. flights by single engine aircraft
(1) The pilot in command of a single engine aircraft must not fly the aircraft under the I.F.R. if the flight is not in one of the following operations:
(a) private operations;
(b) aerial work operations;
(c) charter operations that do not involve the carrying of passengers for hire or reward;
(d) charter or regular public transport operations that involve the carrying of passengers for hire or reward, if:
(i) the operator is approved in writing by CASA to conduct the operations; and
(ii) the operations are conducted in a turbine powered aeroplane approved in writing by CASA for those operations.
Penalty: 25 penalty units.
(2) CASA may issue directions to an operator to ensure that any of the following matters do not affect the safety of a regular public transport operation to which paragraph (1) (d) refers:
(a) seasonal influences;
(b) the conduct of operations by night;
(c) adverse weather patterns;
(d) the terrain below, or in the proximity of, the route used in the operation.
Joined: Apr 2006
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From: Australia
Hopefully commonsense will prevail regarding this.
IMC is not the place for single engine helicopters.
The Private category IFR thing has been exploited a bit in Australia with the B206 and amazingly without major incident but to suggest flying the R44 under IFR in IMC sends shivers down my spine.
IMC is not the place for single engine helicopters.
The Private category IFR thing has been exploited a bit in Australia with the B206 and amazingly without major incident but to suggest flying the R44 under IFR in IMC sends shivers down my spine.

Joined: Nov 2003
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From: UK/OZ
Originally Posted by r44driver
but to suggest flying the R44 under IFR in IMC sends shivers down my spine.
I'm a back seat driver so keep it simple

IFR would help news choppers get to the story through the usual patchey UK weather. An IFR R44 news would be that much more versatile in UK.
Is there much difference in performance stability ect, between a two axis autopilot planned for R44 versus whatever is fitted to an IFR twin squirrel?
Mickjoebill




Joined: May 2002
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From: Downeast
Spinwing,
The US Army has flown single engine helicopters IFR for decades. Jetrangers are the primary instrument trainer at the Fort Rucker Army Aviation School. I did my IF training in the Huey while lots of pilots flew the TH-13T Sioux (Bell 47).
http://www.rotorhead.org/military/th67.asp
I fully agree about having the second engine....and would not object to three or four even.
The US Army has flown single engine helicopters IFR for decades. Jetrangers are the primary instrument trainer at the Fort Rucker Army Aviation School. I did my IF training in the Huey while lots of pilots flew the TH-13T Sioux (Bell 47).
http://www.rotorhead.org/military/th67.asp
I fully agree about having the second engine....and would not object to three or four even.

Joined: Jul 2002
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From: UK
mickjoebill,
A single engine heli will fly fine in IMC (icing conditions excepted). See SAS's post above.
However, when things start going wrong, it's not very nice place to be. Remember, a single doesn't just have one engine, it's also invariably only got one alternator/generator, one hydraulic system, one pitot/static system ie no system redundancy. If anything breaks, things start getting hairy PDQ.
The bottom line though is that if the engine were to stop in a single whilst over a city/built up area, you might have a chance to auto to a clear area. If the engine were to stop when you're IMC, who knows what's underneath you?
HTH,
B73
A single engine heli will fly fine in IMC (icing conditions excepted). See SAS's post above.
However, when things start going wrong, it's not very nice place to be. Remember, a single doesn't just have one engine, it's also invariably only got one alternator/generator, one hydraulic system, one pitot/static system ie no system redundancy. If anything breaks, things start getting hairy PDQ.
The bottom line though is that if the engine were to stop in a single whilst over a city/built up area, you might have a chance to auto to a clear area. If the engine were to stop when you're IMC, who knows what's underneath you?
HTH,
B73
Last edited by Bravo73; 18th June 2006 at 19:42.
Joined: Dec 2001
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From: Philadelphia PA
There is significantly more to IFR approval than just the engines issue.
For starters, you need to have a trim system of some sort for the cyclic in order to satisfy the requirement for self-centering.
There are a whole host of single-point failures on a single engine helicopter that needs serious thought before we start to advocate it whole heartedly.
Personally, I wouldn't think of going IFR without a second attitude indicator - a turn and slip needle isn't really good enough (even though that's permitted under FAA regulations).
A autopilot system, not just a stabilization system should be necessary, if not mandatory for single pilot- (and how do you cope if it fails, one might ask???)
For starters, you need to have a trim system of some sort for the cyclic in order to satisfy the requirement for self-centering.
There are a whole host of single-point failures on a single engine helicopter that needs serious thought before we start to advocate it whole heartedly.
Personally, I wouldn't think of going IFR without a second attitude indicator - a turn and slip needle isn't really good enough (even though that's permitted under FAA regulations).
A autopilot system, not just a stabilization system should be necessary, if not mandatory for single pilot- (and how do you cope if it fails, one might ask???)
Avoid imitations



Joined: Nov 2000
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From: Wandering the FIR and cyberspace often at highly unsociable times
Originally Posted by r44driver
Hopefully commonsense will prevail regarding this.
IMC is not the place for single engine helicopters.
The Private category IFR thing has been exploited a bit in Australia with the B206 and amazingly without major incident but to suggest flying the R44 under IFR in IMC sends shivers down my spine.
IMC is not the place for single engine helicopters.
The Private category IFR thing has been exploited a bit in Australia with the B206 and amazingly without major incident but to suggest flying the R44 under IFR in IMC sends shivers down my spine.
In the event, my co-pilot saw an R-44 pass close by in cloud, an estimated 200 feet below. Someone out there is already pushing his luck.
Thread Starter

Joined: Feb 2001
Posts: 542
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From: Europe
What is the legal situation in the US? I sometimes see 206Bs & Ls advertised as IFR in the US, and seem to recall both aircraft and ops can be IFR approved for S/E helos. Is this right, given suitable equipment?
So far from responses it seems that IFR ops in S/E are permitted for private operations in Australia. Is that the only country or is this legal in the US too? Mexico - Blender? South America?
So far from responses it seems that IFR ops in S/E are permitted for private operations in Australia. Is that the only country or is this legal in the US too? Mexico - Blender? South America?

Joined: Nov 2003
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From: UK/OZ
Would 2 axis autopilot on R44 be safe enough/legal to transit low cloud/rising ground for a few minutes in UK?
Anyone know if it is being designed for serious IMC or just "cruise control" for weekend pilots?
Mickjoebill
Anyone know if it is being designed for serious IMC or just "cruise control" for weekend pilots?
Mickjoebill
Thread Starter

Joined: Feb 2001
Posts: 542
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From: Europe
Mickjoebill
No way will a 2 axis autopilot be suitable for serious IMC flight in a R44. As has been said before, regardless of number of engines, there is a substantial list of equipment required for IMC flight, including a duplex 3 axis autopilot.
No way will a 2 axis autopilot be suitable for serious IMC flight in a R44. As has been said before, regardless of number of engines, there is a substantial list of equipment required for IMC flight, including a duplex 3 axis autopilot.
Joined: Oct 2003
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From: Europe/US
Originally Posted by mickjoebill
Would 2 axis autopilot on R44 be safe enough/legal to transit low cloud/rising ground for a few minutes in UK?
Anyone know if it is being designed for serious IMC or just "cruise control" for weekend pilots?
Mickjoebill
Anyone know if it is being designed for serious IMC or just "cruise control" for weekend pilots?
Mickjoebill
more than all the extra engines or equipment available!!!
However, if flight in IMC is a regular occurance then twin engines are the only way to go! And that includes night flying!!!!!!!!! Unaided, of course!!

Joined: Mar 2000
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From: U.K.
Why do people want to fly Heli's in IMC? A small machine like an R22 or 44 is totally unsuitable for it, being far too pilot intensive.
A good IMC machine (Be it fixed wing or rotary) needs to as stable as possible, something an R22 isn't particularily good at.....
This is more important than any arguments about single engine worries.
With a Heli, if the weather turns to cr*p, then land. That's the beauty of a helicopter, it's ability to land anywhere.
Don't press on into IMC just to get somewhere. If a meeting is that important, get an IR and a fixed wing machine, or spend millions on a suitable helicopter.
A good IMC machine (Be it fixed wing or rotary) needs to as stable as possible, something an R22 isn't particularily good at.....
This is more important than any arguments about single engine worries.
With a Heli, if the weather turns to cr*p, then land. That's the beauty of a helicopter, it's ability to land anywhere.
Don't press on into IMC just to get somewhere. If a meeting is that important, get an IR and a fixed wing machine, or spend millions on a suitable helicopter.



