Hours charged = rotors turning?

[Simon853]

A quick question:

As self-fly-hire and lessons are charged at an hourly rate and measured by the Hobbs meter, how is the meter driven? Is it by the rotor mast turning, or turning under power with clutch engaged?

If it's the former, then in a heli with no rotor brake, that's quite a cost. If it takes approx 4 minutes for a Schwietzer 300's rotors to stop turning, that's £3000 over the length of 150 hours training to CPL, where you're just sat doing nothing waiting to get out! Am I right?

Si

[muffin]

The answer is that it depends on the type of helicopter. The R22 meter runs as long as the oil pressure is at operating level, whereas apparently the R44 works off oil pressure and a microswitch on the collective both being operated. Don't know about the H300 though.

[TheFlyingSquirrel]

The Cbi's have two hobbs Si. One is activated by the weight on the skids and the other by engine RPM. The former is used for maintenance, and the latter, unfortunately for the bill ! It may still be done on time if there is no Hobbs fitted and then I presume it's T/O to touchdown, depending on the set up at the school.

TFS

[Hidden Agenda]

It can also depend on the operator or even the mechanic who installed it.

I have flown machines where the ‘Hobbs’ meter ran if the battery master was ‘on’.

You may wish to check it against your wristwatch.

[ThomasTheTankEngine]

I find it normal that people pay for a helicopter on engine running time, irrespective of how the clock works. The instructor or PIC is responsible for the helicopter during this time so he also deserves to get paid for it.

[BlenderPilot]

The Bell 407 has a switch in the skids that records flight time only when the weight is off the skids, it is also legal to record this "weight off skids" time for maintenance purposes.

[highfinal]

In the aircraft I have flown, on the 300CB's and CBi's, there are two Hobbes meters as previously stated, the maintenance and the revenue. Maintenance meter is the one you read outside the aircraft, and is time spent with the weight of the aircraft off the support of the skids, ie. flying time and the hard work for the machine.
The one you read inside the cockpit is the revenue meter, and it measures time based on pressure in the transmission, ie. all the time that the transmission warning light is not on. It doesn't record before you get up to 2000 RPM on start up, or under on shut down and also if the throttle is chopped. For instance if you have done a simulated engine failure in the hover, and keep the throttle in detent the warning light is on and the meter not charging.
Some unscrupulous students have been known to pull the instrument circuit breaker when solo starting up and shutting down, which disables the inside meter - but this is dishonest, and will almost certainly be noticed by any observant operator, as the normal discrepancy between the two will be much smaller than usual.
If it's cost you're worried about, why not come to the US on an M visa, get your private and instrument, then return on a J-1 with 2 years validity to do your commercial and CFI, you'll save many thousands of pounds and have a great opportunity for work and travelling the States.

[Simon853]

Highfinal,
That's what I'm planning to do. In fact I should be at HAI now, but had to give up my place when my house didn't sell. So I'm doing the PPL in th UK (at extra cost, but I don't have to give up work to do it), and hopefully the UK airspace experience may be of some value when I return from the US.

The reason I asked the question in the first place was because a friend told me about a guy he used to go flying with that would apparently sling a belt to catch a slowing blade, hoping to reduce his costs! The physical danger and risk of damage go without saying, I was just interested in whether it achieved his goal. (Sorry, I don't know the type.) I think I'd rather take the hit in the wallet that risk that...

Si

[highfinal]

Hi Simon,

Don't know if I'd be wanting to learn much from someone who stopped the blades by slinging something over them! There's a funny incident in Robert Mason's Chickenhawk about someone who should've known better doing that.
HAI is a great school, and having a JAR ppl will be a great advantage when you start your training there. I hope your training goes very for you, and you enjoy Florida.
HF :ok:

[Flingwing207]

Hi highfinal,

As others have alluded to, the "revenue" Hobbs on the Schweizer 300CB/CBi operates when the main rotor transmission oil pressure reaches 2.5 PSI (which also extinguishes the MR transmission pressure light). However, it's not quite true that the Hobbs stops in autorotation. For the transmission pressure to go below 2.5 PSI, the main rotor has to be turning less than around 150 RPM. Long before this, the helicopter would cease flying.

As long as Hobbs meters have existed, student pilots have been complaining about billing procedures. If you look at the Hobbs for a typical training Schweizer, you will see around a 15% difference between maintenance and revenue Hobbs readings. A school could easily bill off of the maintenance Hobbs and just charge 15% more. In the end, it all comes out the same.

[Heliport]

"As long as Hobbs meters have existed, student pilots have been complaining about billing procedures."
If there are two meters - one genuine and one used to charge them - is that surprising?


"A school could easily bill off of the maintenance Hobbs and just charge 15% more."
So why don't schools that choose to make an extra 15% off the Hobbs meter do that instead? To make their published hourly rates look cheaper than they really are?

"In the end, it all comes out the same."
It may well come to the same amount, but people tend to resent hidden extras. They'd know where they stood if the 15% was included in a school's published hourly rate.

[remote hook]

For general charter, I use the wrist watch or dash mounted clock. Hit the starter, start billing, roll the throttle off, stop billing.

The hobbs is a horribly inadequet method of billing. Sitting on a horrible off-level or rickety mountain pad where you NEVER roll the throttle down or have to maintian some pitch? You bet I'm billing for that.

RH