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View Full Version : Datcon hours meters in Robinsons.


Stampe
16th Jul 2005, 21:42
A friend who is learning rotary at the moment tells me the datcon meters on the fleet he is learning on start counting as soon as the master switch is on.Is this true ??.My own experience of datcons on fixed wing has been master switch plus oil pressure to start the counter. At rotary rates of hire paying for the preflight and before start checks seems rather unfair.Thanks!!.:ok:

Bitmonx
16th Jul 2005, 21:56
To answer your question: No it does not start counting when the Master switch only is turned on. As you said, the oil pressure switch has to be sensing (I don't know how much) oil pressure to activate the meter. In the R44 the meter is activated by a micro switch mounted on the collective and closes as soon as some collective is pulled. This is called a collective hobbs.
However, if in your aircarft the meter is starting with only the master switch on, then you are beeing ripped off. If so, I would confront the owner and ask for a refund of over charged flight times.

Cyclic Hotline
16th Jul 2005, 22:34
In addition to oil pressure/collective hobbs time on our helicopters, all our fixed wing aircraft use a 40 knot pitot pressure switch to activate the tach. This way all our maintenance is predicated on flight time, not engine running time. Works out at a large number in managing maintenance and overhaul costs.

EMS R22
17th Jul 2005, 06:34
The hour clock on one of the 22's i trained on had a switch to turn the clock off and on. It was the heater circit breaker!Is this a mod or do they come out of the factory like this.

EMS R22
17th Jul 2005, 21:10
This" pulling of the circit breaker " was about 4 yrs ago and was bl:mad: y b:mad: t! Just madness that you would risk lives for the sake of a few extra dollars. I dont think it comes as a surprise to anyone.

rotornut
17th Jul 2005, 21:33
The place where I trained didn't start counting the time until you actually lifted off.

RotorHorn
18th Jul 2005, 12:16
I've heard of some R44 pilots flying a sawtooth flight profile so that they can go into an auto on half of the journey and not have to pay (because the lever is down the datacon's not registering) !!! :rolleyes: :rolleyes:

Never got around to figuring out how much money they actually think they are saving, since they must be flying slower in the inital climb, before each subsequent 'auto', which is also at less than cruise-speed.

Personally, I just fly level and have done with it!

RH

ThomasTheTankEngine
18th Jul 2005, 20:26
Hi Rotorhorn

The R44 has a sensor to sense when its on the ground with the collective down and when it's in flight in auto, I don't remember how it works but it's there. So when your in auto the datcon is turning.

Gaseous
19th Jul 2005, 00:04
Hi Thomas,
It must be new 'cos I've got my Astro electrical circuit diagram and the only sensors are the collective switch and the oil pressure switch. Anyone got a Raven schematic?
Rotorhorn's sawtooth flight plan works in an Astro. ( It was his big brother who warned me about that one).

Incidently, my helicopter didnt have a datcon at all so I got one fitted. I want to know when its worn out! Only a moron stretches componant times.

RotorHorn
19th Jul 2005, 09:48
TtTE

Not heard about that one.

Tornado ADV has a WOW (weight on wheels) switch, which I think stopped pilots jetisoning fuel/firing missiles when the aircraft was sat on the ground :-) ). so I can imagine there's a WOS switch (Weight on Skids) equivalent. Just not come across it in a Robbo yet. As Gaseous asked, Is it only on certain models?

Gaseous.
I'm the older one! Its only 10 minutes but it counts in an argument! Anyway, he's the ATPL, I'm just the PPL so if he said it, it must be true ;-)
p.s. PM sometime and let me know how you're getting on with that Enstrom....



RH

ThomasTheTankEngine
19th Jul 2005, 12:52
Hi Guys

I was told on a Robinson safety course a few years back that there is a sensor to sense when your in flight and the collective is fully down (This information came from a reliable source) I will find out more on how the sensor works and get back to you, It could be skids activated or RRPM activated.

cyclic flare
19th Jul 2005, 13:01
If you turn the master & Alt off whilst cooling the donkey it stops the ticker in the 22.

Why cant the 22 be the same as the 44 and be collective activated engines would then be cooled enough without having to rush before the next tenth on the clock.

slowrotor
19th Jul 2005, 13:50
I was training at a school that had two hour meters installed in each helo (S-300).
One meter clocked time from master on, the other from collective up I suppose.
The charge was for master on time. The other clock for maintenance.
A typical flight took about 2 min for prestart, 4 min warmup, 10 min flight to practice area and 10 min back and another 4 min cool down. That leaves about 30 minutes from each hour lesson for actual training. Needless to say, I have abandoned that school.

Whirlygig
19th Jul 2005, 14:07
Too right Slowrotor,

I fly the S300 and am charged from lift to land; flight time only. Although I did go to another school that seemed to be cheaper but then I found out they charged from rotor start to engine-off. Can make the difference of 10-15 minutes of cost.

If an aircraft's maintenance schedule is based on a particular criteria, then should this same criteria be how the customer is charged? Or am I just a simple accountant?

So, anyone learning or training - find out how they measure the chargeable time!

Cheers

Whirlygig

Gaseous
19th Jul 2005, 21:51
My R22 training was datcon recorded, engine start to stop time.
My Enstrom training - no datcon at all, and an hour was an hour in the air. It made the real cost difference much less than the advertised cost implied.

Rotorhorn, I didn't know you were twins. You looked younger. (Sorry S). The Enstroms great. Give me a ring if you can get over and we'll go for lunch. Whitewell, Swan or Devonshire Arms?

overpitched
20th Jul 2005, 01:28
In the earlier 22s you could pull the instruments circuit breaker and that would stop the clock. I think from memory you would lose oil pressure guage and a few others, maybe cht, but the oil pressure light would still work if oil pressure was low.

As stated before information on the operation of this r22 feature came out of the "mustering" section of the flight manual.

Of course there is a downside to using this handy feature and that is that the blades depart the aircraft in flight.

IFMU
20th Jul 2005, 02:00
I learned to fly in an enstrom. It was wired to run the meter with the master on. My instructor coached me to do the warmup (especially in winter) with the master off, so as not to get burned on the cost.

belly tank
20th Jul 2005, 02:23
under the bonnet in a 206 right above the hour meter is a circuit breaker! good one Bell :uhoh:

Flingwing207
20th Jul 2005, 03:08
We have installed a second Hobbs in our R44 which runs with engine oil pressure - this is what we use for billing (we use the collective-controlled meter for MX)

The 300CB/CBi have the MX Hobbs run by a squat switch on the skid gear, and the revenue Hobbs runs when the MRGB oil pressure reaches 2.5 PSI (warning light out).

deeper
20th Jul 2005, 06:09
Slow Rotor,

Surely you were using the ten minutes out and the ten minutes back practicing flight manouvres. Was the instructor doing the flying??

Except for the Robinson helicopter that is lifed from key on to key off I thought most helicopters were skids off to skids on for the maintenance release and engine start to engine stop for revenue hours.

If the student takes his hands from the controls whenever the instructor is demonstrating something, and that happens a few times during the hour, say six minutes of flight, then the student is paying for ten hours out of every hundred to sit and watch, to someone who can already fly. Thats a lot of bucks in the slipstream.

Good idea to change schools.

slowrotor
20th Jul 2005, 14:24
I think flight time and maintenance time is suppossed to be clocked for actual flight (off the ground). But most schools sign your log for the time used (master on) that they charge out to the student. It would hard to charge for 1.1 hour and sign the log 1.0 hour.
The previously mentioned school also charged for ground training, which is common I suppose. But they would bill me for the instructors time while I performed the preflight everytime. That really angered me. The preflight check list was about 6 pages and takes about 15 min. Then the post flight ground instruction was usually about 5 min and the charge was 30 min(to include the preflight).
Shop around.
Another freelance instructor gave me 3 hours of ground for free. Go for a freelance if you can.

helipat
21st Jul 2005, 11:56
On the first R44 the hobbs was working on the oil pressure as on the R22. It was later changed for the collective activated.

The FAA stated that only the flight time is the way to mesure helicopter time.

Then it is authorized by a lot of FSDO to have the R22's hobbs modified to be collective activated as on the R44. However do not expect to have the factory endorse it...

As an owner I prefer this solution as nobody needs to cheat on the cool down time

As a customer I have more for my money.

As an operator/CFI I hate it as I can charge less and log less hours...

800
21st Jul 2005, 23:07
On the Airservices Australia website there is a description of "Flight Time" reguarding log books

This states; "In the case of a helicopter, whenever helicopetre rotors are angaged for the purposes of a flight, the time will be included in the flight time"

http://www.airservices.gov.au/pilotcentre/specialpilotops/logbook.pdf

TinKicker
22nd Jul 2005, 04:09
The R22 Maintenance Manual - Section 3 - paragraph 3.002 states:

It is the operator’s responsibility to maintain accurate time-in-service records of the airframe and life-limited components. An hourmeter activated by engine oil pressure is standard equipment in the R22 helicopter and is an acceptable means of recording time-in-service.

later in the same section it states:

The approved overhaul intervals and the fatigue service lives listed in the Airworthiness Limitations Section are based on FAA Advisory Circular 20-95 which assume that 10.5% of the operating time will be in autorotation, runup, or shutdown. Therefore, if an hourmeter activated by the collective control is used to record the time-in-service, the values recorded must be multiplied by 1.12 when determining replacement times for life-limited components, engine and airframe overhaul periods, and other periodic inspection requirements.

The R44 Maintenance Manual - Section 3 - paragraph 3.002 states:

It is the operator’s responsibility to maintain accurate time-in-service records for the airframe, engine, and life-limited components. An hourmeter activated by engine oil pressure is standard equipment on earlier R44 helicopters and is an acceptable means of recording time in service. Later helicopters are equipped with an hourmeter activated by a combination of oil pressure and up collective; the hourmeter will record time only when engine oil pressure exists and the collective is raised.

Tinkicker...

Stampe
23rd Jul 2005, 10:10
Thanks for all your answers guys looks like we,ve opened up the proverbial "can of worms".Seems like it would be a good idea when choosing a helicopter school to establish exactly what the datcon is recording as well as the notional rate.Could make a huge difference given the amount of time helcopters spend on the ground and apparently cheapest may well not be.Caveat emptoir:ok:

muffin
7th Aug 2005, 15:32
I have just been catching up on the tech logs for my R22. We have done 60 hours in the last 10 weeks in a total of 120 flights. This is an average of only 30 mins per flight. Assuming a 5 minute startup/warmup and a 5 minute shutdown/cooling period per flight, that means we have spent 20 hours out of 60 on the ground with the collective down and the Datcon ticking away. So if it was being charged out on the basis of the Datcon that would be a lot of pennies for doing not very much.