Heli routing over Hammersmith

[betterfromabove]

Hi,

PPL(A) recently moved to Hammersmith.

Am just curious, there seems to be a clearly IFR routing commercial helis out of Battersea use that runs northwards over Hammersmith, yet I can't find any sign of it in the heli-routes.

It looks like a standard route, since is used all day long!

BFA

[ATCO Two]

There are no IFR routeings inbound to or outbound from Battersea. The only aerodromes authorised for IFR helicopters are Heathrow and RAF Northolt. There is a fairly standard SVFR route from Battersea - Barnes - Brent Reservoir that operates initially not above 1000ft QNH. This is available to twin engined helicopters only.

[betterfromabove]

Why I'm curious is that it they seem fully IMC some days....

[ATCO Two]

Determining in-flight weather conditions is the pilot's responsibility, and under a SVFR clearance, helicopters must remain clear of cloud and in sight of the surface. Additionally, a pilot must remain in flight conditions that enable him to determine his flight path, remain clear of obstacles, and operate in accordance with Rule 5.
Battersea will normally be closed to traffic unless the cloudbase is 600ft or greater, and/or the met vis is 1000m or greater.

[chevvron]

Two of the SVFR helicopter routes meet at Craven Cottage aka Barnes VRP.

[betterfromabove]

Hmmh, wonder if I've opened a can of crawling pink bird-food here....

A S-76 has just gone over Hammersmith literally 5 mins ago heading northbound, clear of cloud, but noticeably low. Couldn't be more than 500'AGL.

EGLL METAR is showing FEW070.

Obviously twin with ATPL(H)/IR aboard and super nav equipment etc, but seems rather tight to be working SVFR.

Guess my point is that those us fixed-wing would never get or attempt SVFR in these conditions, even with an equally well-equipped a/c (e.g. G1000 C182 or SR22 say).

Know a heli gives obvious other PFL options, hence the different Rule 5 criteria, but over a crowded conurbation, am wondering at the risk mitigation?

A catastrophic hydraulics failure or tail rotor loss does not give too many options or time at that height I would have thought.

Any thoughts, comments?

BFA

[Whirlygig]

Hmmh, wonder if I've opened a can of crawling pink bird-food here....Not really ....

Are you sure you can judge the difference between 400 and 600 feet? FEW at 7,000 feet is irrelevant if the aircraft must remain not above 1,000 feet.

A Sikorsky 76 is a twin-engined medium helicopter and a very different animal to a single engined Cessna or SR22, however well-equipped they may be. The 76 is likely to have two ATPL/IR pilots on board for a start, auto-pilot, emergency systems etc etc.

Cheers

Whirls

[John R81]

If he is on the heliroute, that route is chosen because it offers options in the case of catastrophic emergency. A heli can land on a relatively small patch of ground - hence the different application on clarance rules. It may be that though this looked tricky from your viewpoint, it looked very much different from his - and that is the view that counts.

Even off the heliroutes, there are specific rules for twins which are different to singles.

Anyway, with a mode S transponder operating you can rest assured that his exact position and hight was known to ATC. Very, very unlikely that he would break any rules with a very clear record being kept of his every move.

[ShyTorque]

Nothing to suggest you are witnessing anything out of the ordinary. A SVFR clearance requires the aircraft to be flown clear of cloud and in sight of the surface. The 500 foot rule applies, the 1,000 foot rule doesn't. The arrival and departure procedures from Battersea are well laid down. The aircraft will be in contact with Heathrow Special over that area and are tracked closely on radar, with a transponder code given. IFR aircraft have Mode C so the altitude shows up on the controller's screen. Due to the proximity of inbounds descending to LHR over that part of London, helicopters are given a maximum altitude to fly, i.e. not above 1,000 feet, London QNH. The route H3 to the west of Hammersmith carries a maximum altitude of 750 feet.

The northbound routing is not given to single engined aircraft.

Helicopters suffering a "catastrophic hydraulic failure"?

Helicopters have either no hydraulics (in which case the system can't fail), one hydraulic system (in which case the aircraft is flown in manual), or two hydraulic systems, in which case the warning light comes on (only amber, no catastrophe here) and the other system carries on powering the controls). The aircraft continues on its way.

I think you should be more worried about something like a Boeing 777 suffering catastrophic fuel system icing, running out of engines and landing short of the runway at Heathrow.

Btw, it isn't totally unheard of for helicopters to fly the ILS at LHR, totally in cloud, down to a 200 foot cloudbase. I don't see a difference in risk.

[John R81]

Betterfromabove

From your profile you are PPL(A) so no-one here is going to give you a hard time for asking questions about heli operations. If you want to find out a little more about what helicopters can do, I suggest that you post in the "Spare Seats" in GA and try to get a ride. It would not take long to show you how (for example) a single can be flown "no hydraulics". I fly singles, and frequently practice both flying and landing without hydraulics just in case I ever need to. I can also fly without the tail rotor (landing gets more difficult but I can still safely leave London without it, if I have to) and again I practice this regularly. Finally, we regularly practice "engine-off" landings just to keep sharp.

If you are very lucky, even more lucky than just to get a seat, you may even get a flight through the heliroutes. If you do you would see how many options there are for landing in the remote chance that the donk stops. Include in this potential landing area the Thames, as any single undertaking passenger work has to be able to land there in an emergency.

The size of gap needed to put a heli down without an engine varies with the size of the helicopter; but a large machine is likely to be multi-engined and a multi is more likely to be able to leave the area on remaining engine(s) to land at one of the many airfields surrounding London. For a single the size of an EC120 (5-seat single turbine, 1.7ton) the area required for a forced landing is about the size of the penalty zone on a football field (though more is always nice!). In a forced landing we don't have the forward speed of an aeroplane.

Regards

John

[betterfromabove]

Guys

Thanks for all the detailed replies....this place is like a university sometimes :ok:

...er, that should have been FEW007 at EGLL, sorry(!)

Aviation is full of these cases of where the risk is not quite what it first appears (in both senses).

My question really comes from the risk reduction behaviour we're taught as PPL(A)'s. Even more for IMCR, where one major consideration for emergency contingency is the fact of what a low cloudbase does for diversion / engine out options.

Clearly, the experience and skill level, plus the equipment on board, is vastly superior to a PPL(A or H) - who without an IR should not be airborne on a day like today - but is there not a risk from forcing these helis to effectively scud-run to remain VFR in the 500-900'AGL height range?

Even despite being M/E and the other mitigating factors in crew skill levels, does not 500'AGL (let's say...) when marginal like today, not give long to get to one of those PFL bolt-holes....!?

BFA

[John R81]

If you check the CAA website you will see that the minimum requirement for a heli to run IFR includes twin engines, stablisation, etc - you can't get single engine IFR helicopter. So even with one engine out at 500ft, you still have power - usually enough to continue to fly, though often not enough to hover. Hnce you would vacate on one engine, divert to an aerodrome and erform a run-on landing.

Not a big issue, really.

[ShyTorque]

I think the "engine failure/PFL" case is being overstated.

Again, the route in question is NOT given to single engined helicopters. The risk of two helicopter turbine engines failing simultaneously is very small indeed. The S-76 (and other twin engined helicopters) provides Class A performance, just like a good multi-engined fixed wing can i.e. the aircraft can either safely land on below takeoff decision point (a speed/ height combination) or continue with the climb and cruise to a safe landing elsewhere, albeit at a reduced cruise speed.

[DennisK]

Err .... Bell 206 of Bristow. CAA approved for IFR training. DRK

[Bravo73]

Err .... Bell 206 of Bristow. CAA approved for IFR training. DRK

Err .... not any more. 'Double India' (the venerable 206 in question) was sold off a few months ago and has now gone on to another life.

[ShyTorque]

But as many of us know, that aircraft is/was a "one-off" based on grandfather rights.

In any case, it would never be flown in these circumstances.

[herman the crab]

Don't know about the UK but there were R22 IR trainers in the US a while back.

HTC

[Whirlygig]

FAA IR is a different kettle of fish ... there are no IR certified single-engined helicopters in the UK anymore.

Cheers

Whirls

[Gordy]

herman the crab

Don't know about the UK but there were R22 IR trainers in the US a while back.

Yes there are thousands of them....BUT they are NOT certified for IMC. You can fly them on an IFR flight plan but must remain in VMC.

[Pandalet]

There are still a few IFR singles floating around Europe - I'm aware of a school in Portugal running an IFR S300 on a SE IR(H) course. None in the UK, though, since II got retired (as has already been pointed out).

[herman the crab]

I am aware that the FAA IR is different to UK, etc, etc. and that they were just trainers but as someone pointed out the 206B I thought I would add a bit of useless information.

HTC

[Flingingwings]

but is there not a risk from forcing these helis to effectively scud-run to remain VFR in the 500-900'AGL height range?

Er no. The Brent-Barnes routing is normally given at not above 1000' QNH, regardless of weather conditions. Nobody is forced to scud run, if the flight can be conducted safely and legally then the weather angle is rather academic.

[Sir Niall Dementia]

In fact the usual clearance given at the moment is "The 133 radial to Brent, not above 1500' and then not above 1000' Heathrow QNH Brent to Battersea avoding R157."

If you want to fly tight to R157 then Brent to the Westfield Shopping Centre then to Earls Court brings you close to the boundary, but you do get closer to Hammersmith which is possibly why BFA is seeing more helicopters. Also with cloud at 1000' and all the city buildings a ground observer may be hearing "reflected sound" where the aircraft seems to be in one direction, but is in fact different place and therefore can't be seen when the ground observer looks for it.

Last week the weather was on the limits for Battersea, the slant range was good, but the horizontal range c***. I did wonder if anyone on the ground would have been able to see my aircraft, when my view of the London streets below was fine.

As for bimbling around in cloud at 500' the risks to career would be too great to take a chance on getting caught.

Finally most PPLs let alone fixed wing tend to be surprised at the level of kit we have in modern twins. Auto-pilots, couplers, amazing moving maps, sat- phones and a single engine performance that is better than the singles we originally trained on.

God we're mollycoddled today (Just no-one tell my boss:E)

[John R81]

Actually, not bad kit in my single.

Flymap 7 moving map with current charts (including the heliroute charts)
Virtual horizon with electronic AH altitude and height over ground displayed
Radio altimeter (in addition to the 2 altimeters)
Mode S transponder
2x radios
VOR navigation
Second Garmin GPS with the usual ATZ information

And all the usual flight instruments.

I don't have 2 engine, autopilot or stability control but I do know precisely where I am, at what height and my clearance over ground. Mode S means that ATC know also so I don't break any rules (never did even without all that kit).

[betterfromabove]

Thanks guys for all the fascinating answers...the rotary world is indeed a different one to fixed-wing.

Couple of questions still occur to me though:

1. Whether routing into Battersea or not, when cloudbase is of order of 700'AGL or less, with the right aircraft and licence, does this mean you can fly through the Heathrow zone IMC? So, the SVFR is just a convenience (as for fixed-wing) when conditions permit....

2. Does the concept of "infringement" off a heli-route exist? Or is the fact you're talking to Heathrow Special negate this possibility? I've never seen any stats for heli-route infringements as such....

PS. Yes, took a R22 trial lession afew years back in Jo'burg (much cheaper than UK!) and decided it would be a very bad to ever step foot in a chopper again, as I would bankrupt myself....it was waaayyy too much fun. When you get back in a C152 you sort of wonder why the wings are not doing anything....

BFA

[ShyTorque]

1. Yes, why not? I've carried out IMC instrument approaches to LHR in a helicopter a few times. It's difficult to get fitted in but it can be done. Can only be done in an IFR twin, of course.

2. "Infringement"? ATC have to maintain standard IFR separation between aircraft. If inadvertently going off the cleared route means that is compromised, then, yes, an infringement has occurred. It did happen a while back, an aircraft overshot a cleared waypoint near you (went too far west at 1000 feet, max height 750 feet) and standard separation was lost against an inbound to LHR, causing an investigation.

[betterfromabove]

Shy Torque - sounds like you have a fine job there!

[Helinut]

Re:

1. The definition of IMC and what SVFR means varies between types of aircraft AND the Class of airspace. Also, cloudbase has nothing to do with whether you are IMC in a helicopter in Class A airspace. The limits to permitted visibility for SVFR in helicopters varies depending upon what you and others are doing and where (from 1 km to 10 km if I recall correctly). However, the cloudbase en-route is never a limit to SVFR.

If you are IMC in Class A airspace you must be IFR, but you could be if you had the IR and a suitable helicopter, as ST suggests.

2. I am not quite sure that I understand 2. ATC gives you a clearance, If you follow it you are OK. If the conditions prevent you from continuing in a accordance with the clearance, you tell ATC and a plan is organised to sort it out. Lots of hele twins using the London Zone SVFR can accept an IFR clearance, although it may not get them where they wanted to go (e.g. no IFR approach to Battersea).

[betterfromabove]

Yes, think I understand now the blend of SVFR and IFR that's being used by choppers within the Heathrow Zone. As F/W GA of course, SVFR is pretty much you're only option and that's only around the fringes or the BUR-Ascot transit.

Am working in the area of infringements, so was interested to hear what would constitute an infringement in terms of the heli-routes, if SVFR. How far off track do you have to be to be considered effectively "in the zone"??

[ShyTorque]

You're "in the zone" all the time your track takes you inside the lines on the chart.

Again, helicopters are put on the published routes so that the IFR traffic can be ensured the normal IFR separation from all traffic inside Class A airspace. Radar controllers understandably get concerned if a helicopter strays off the allocated route by more than a few metres and will correct the pilot. When LHR is using the easterly runways, some heli-routes (e.g. H3) are closed in order to ensure continued separation.

Helicopters under SVFR are allowed to pass each other along certain routes, such as those following a line feature like the Thames, if both pilots agree.

[Helinut]

The helis over Hammersmith going North are probably not on the heliroutes and would be twins.

I don't know what limits ATC use to determine whether a hele is OFF the route. It often is not much though: they have eyes in the backs of their radar heads. I think they listen a lot to the voice on the RT. I suspect they get more concerned when the separation between IFR traffic and the on route approaches the defined separation limit.

As ST already said there is an opt out from normal IFR radar separation standards if 2 heles are on a route, the vis is better than 6K(?) and the pilots agree. However, if one hele is OFF a route then ATC must apply standard separation. You get some odd effects. If a police hele is on scene in the Zone off a heliroute but close to it within standard separation limits, then heles on the route will get held. However, if the police hele moves off scene onto the route, ATC can clear the other hele through. Police pilots will often volunteer to move back on the route if they can to allow this.

The other main exception to standard separation is when ATC can separate traffic visually. This happens in ATZs in the London zone when the TWR controller is visual with both aircraft. That's how heles can do a LHR crossing which is one of life's real buzzes no matter how many times you do it.