Max perf. take off and Steep landings...

[MD900 Explorer]

Some countries CAA's insist that these are a part of the CPL/PPL curriculums..... others don't (Max performance take-off and steep approach to a spot)

How many actually were taught this vs how many wern't, BUT how many are doing this as per daily in a job situation/ or are trying as a private pilot to do these and getting into confined area's on a regular basis?

As i see it the UK does'nt acitvely train on it.. (Neither do they train CPL/PPL's to control throttles, nor loss of tail or auto's to the ground)...unless you become an instructor..?

opinions please

MD :(

[kiwi chick]

I was taught confined landing in my PPL training, then when doing my CPL the confines REALLY became confined!

Possibly not compared to those doing it "real life" but things like little cut out areas on a river bank in the mountain ranges surrounded by trees on three sides; or landing beside a hunting hut in the ranges where there's a bridge in the way for one approach, and sharp a corner for the other.

As far as Autos go, from PPL training I controlled the throttle but the instructor always had a hand on it until I got into CPL training! Can't say I blame him :ooh: We did a couple of autos to the ground but they weren't part of the syllabus.

LTE - we cover pedal jams - left and right - in CPL training (and discussed all sorts of things in my flight test (CPL) that could possibly go wrong).

Max performance take-off? Hmmmm? Trying to work that one out?! But we did limited power ops - running take-offs and running landings etc.

Hope this helps?!

KC :ok:

[helimutt]

I don't for one minute think you weren't trained to use throttles, do steep approaches or Max perf take-offs if you were trained in the UK.

Maybe this shortfall in your abilities or experience of these techniques is down to the fact you trained at so many different places instead of getting good, continual training?

Ask anyone who flies an S76 offshore. Max perf take offs and landings etc are often the norm!! You probably won't experience it tho.

[VfrpilotPB/2]

MD,

Trained for my PPL(H) in the Good Ole UK,

My Lady instructor put me through hell and high water getting everything that needed to be done, done, and done correctly, running take offs, run ons from power off,jammed pedal, tight areas downhill, uphill landings, spot landings, confined areas, getting into and out of Vortex ring state, bad weather, good weather, high wind low wind, she put me thru hell, but I am here telling you some ops really made me realise just what you can do when shown, I am naturally cautious but I now know just how hard some CPLs have to work when I see where they land and take off !

Peter R-B
VfrpilotPB

[heli_spy]

Hi MD
I did a commercial flight test recently in the UK to convert my Australian CASA CPL(H) to a JAA CPL(H). I can confirm that, among other things, I had to do the following on my flight test.

An autorotation/engine off landing to the ground with me controlling the throttle.
A circuit and landing with the governor off.
A steep approach to a confined area.

With regard to the 'training required' prior to the 170A and flight test:

All auto's were to the ground (wind permitting).
Most if not all all approaches to a confined area were steep approaches.
Max performance take offs were the norm for departures from confined areas.
Jammed right pedal / loss of tail rotor were practised regularly.
Limited power take offs and landings were practised regularly.
Governor off was practised regularly.

No real difference really to the Australian training/syllabus as I recall. It was pretty full on!

(FYI; I did my Australian CPL test in a Bell 47, my UK CPL on a R22)

Hope this is of interest to you.

Fly safe.

[thekite]

I did the same flight test as you, except that I did the test in a JetRanger on low skids. Hydraulics off occurred every flight, as did a no-flare touchdown auto. Thing that baffled me was the insistance of the examiner to use a nominal Ng figure as the limiting factor for limited performance. :confused:
Go figure! In Aus I was used to watching Tq limit in the morning then TOT in the afternoon. No wonder those b******s lost their Empire!:rolleyes:
thekite

[MD900 Explorer]

Thanks for the replies so far. I was only curious to see how, if at all these techniques feature accross the board with regards to different countries training syllabus' for various licence types. I guess it is also down to the terrain you fly in, and having to adapt to that.

Cheers

MD :ok:

[Gomer Pylot]

My training was long ago, with the US Army, and we certainly did all sorts of takeoffs and landings. We did all sorts of them after training, too. I do max performance takeoffs and steep landings on a daily basis in my job now. Night approaches to an accident scene, and the subsequent takeoffs, demand them.

[Pilot DAR]

I'm on the last hour of my PPL training. My training has included all of the aforementioned, except getting into and out of ring vortex state. I've only been taught to stay out of it! Only done one full on auto, but I've have full control of the throttle the whole time. That can lead to added stress in a Schweizer 300!

I did some flying out west last summer in a H500D, and that company's standard for confined areas is 50' x70'. I was directed into a spot of that dimension, with 50' trees on three sides, and a river under the tail. I was really aprehensive, but what made it easy was the installed survey boom, which was projecting 3' further than the rotor disk out the front. I tucked it up to the nearest tree on the centerline of the spot, and everything worked perfectly.

We'll see what the flight test examiner expects of me in the next week or so!

Pilot DAR

[MD900 Explorer]

Some have mentioned twin perf. stats.. I am not interested in Cat1 or perf. Cat A stuff. There have been other threads that have covered that quite well. And as for Helimutt's suggestions, i can concur that i would never fly an S-76A offshore, doing all the cat. A stuff i have just mentioned.

Glad to see that NZ and Canada do that kind of stuff, but terrain demands it.

Must have had a brain fart, but i assumed that everyone who goes into a confined area (in a single) did steep approach and max pef. take off all the time? Ooops.

As for the throttle issues... probably deserves another thread?

MD :oh:

[somepitch]

i trained on the 47 G2 in the mountains and just about every takeoff and landing outside of the airport was max. performance! i'm thankful for the experience because my first job was flying another G2 on bags at max gross in the summer...:}

[remote hook]

Can I ask what on earth a "no flare auto to touchdown is?" Where I come from, that's a ditch in the making.....
Must have read it wrong.
RH

[helimutt]

You didn't read it wrong. It's the sort you would do probably at night, @40kts, using maximum available pitch at the bottom to cushion the blow!! :E

MD, I would probably never fly a 76A offshore either!;)

[rotarypilot]

Well its been my experience that while effective in getting new pilots to think in the right way my training did not go nearly far enough to prepare me for what I would encounter on the job in Canada with regard to steep approaches and max performance T/O's. As with so many other things you learn the hard way by either scaring the :mad: out of yourself or having an accident. I was fortunate to have never had an accident when I was a green pilot as there is at least one time that had I not been so fortunate to get clean air into the rotor by sheer dumb luck I could have had an accident involving some very high trees while I was trying to depart a gas well with an R22 and a very large (and frightened) operator onboard.

Looking back I wish my training had focused more on advanced procedures for situations which would actually be used in the bush however aircraft time is so expensive and the require times to earn a CHPL in Canada are so low that there often is not time and or funds to do so. A CHPL is simply a license to learn. In my opinion learning these fundamental skills is essential as if you don't you'll surely be at greater risk of having an accident.

[Shawn Coyle]

Wouldn't better performance charts that would tell you whether you could hover at some intermediate height between OGE and 2' be a good start?
There are no charts that tell you anything about a maximum performance takeoff- no speeds to use, no pitch attitudes. Nothing at all related to 'maximum performance'.

[Gomer Pylot]

Performance charts in the RFM don't help much. Don't anyone try to tell me they dig out the RFM and go through the charts while flying. Or before launching for a scene flight, for that matter. Or even before a trip offshore. RFM performance charts are mostly used for checkride purposes, and I almost never see a pilot going through them at any other time. What we need is something in the cockpit, easily available and readable. It's not that difficult, given modern computer technology, to have a set of sensors that detects temperature, altitude, weight (given an initial takeoff weight, and knowing fuel flow) etc, consults a table for the maximum hover, and displays it digitally. The main obstacle to something like this is, I think, liability, and I would be amazed to see it happen. But I continue to dream...

[RVDT]

Gomer,

I thought that stuff was standard in VEMD equipped EC Singles. IGE OGE calcs etc.

[Gomer Pylot]

Could be. I haven't flown anything from EC, except AS350Ds long ago. Nothing I fly now has it, though.

[Shawn Coyle]

The point I was trying to make is that we are not well served by civil performance charts. They don't really tell us much that's worthwhile, and if you have an above-spec engine, don't tell you much at all.
I can't imagine the FW world putting up with this state of affairs - that is, performance charts that don't tell them what they need to know - so why do we????

[topendtorque]

The point I was trying to make is that we are not well served by civil performance charts.---
that is, performance charts that don't tell them what they need to know - so why do we????


Only to make money in airwork.

I don’t believe that Max Perf Take Offs should be taught to ab-initio until they get into the air work area when they might be useful. At best they are risky and a handful, at worst an insurance claim.

Those who have been spoilt in say Blackhawk’s where ample power will lift even the heaviest box of biscuits before journeying forth need not worry their grey matter too much about it.

The FAA helicopter Handbook describes the technique OK except that it leaves out the most crucial aspect. That is what the desired target speed to perform the manoeuvre is. Also it fails to remind the student that in like fashion to the vertical take off if the A/C won’t climb at full power to achieve either vertical or a max perf take –off then weight must be dropped of.

The difference being that in the vertical, one has the luxury of finding out in a calm environment whether the power applied was enough or not, without risk.

Let us assume that a max performance take off is simply the maximum angle of sustained climb and not a limited power take off, where one may bounce along for a while on the firma terror to translate.

It is a useful skill when lifting out of a confined area where one cannot cut down the obstacles to make take-off a normal procedure with more margins for heavier loads and thus more financial return on the operation.
Likewise the vertical take off is easy and safe but useless when operating hot and high and trying to make money.

The relative A of A at the right airspeed is what makes the manoeuvrer work. Make it too high and RPM drops of, and or allow airspeed to drop off and the A/C falls back into the trees. Many very experienced pilots have been caught out right there, so do not go any further without help if you have never done it.

One can plot the airspeed or experiment to find it. The graph that I use for instruction purposes suits a ’47 G5, but can be easily modified to any type.

The usual two axis are the (AB) vertical being power required from zero up toward (B) to max power available at the top, and (XY) across the graph is airspeed pegged at five knot intervals.

Start at zero airspeed OGE and plot the power required every five knots. You should see a slight rise in power then a long drop to the minimum power airspeed followed by a slow rise to the max airspeed capable at full throttle. Make your graph neat and flowing.

Three things can be found from it.

1)Draw a tangential line from the point AX to touch the curve on the upward rise of power applied. Drop a perpendicular from there and hey presto, you will find max range airspeed. On the ’47 G5 it is about 62 knots
2)Observe the difference between power available, say 26.2 inches and power required at the minimum power required airspeed about 17 inches; this will be the airspeed (about 45 knots) for max ROC.
3)Draw another tangential line from where the max power line intercepts the AB line down to touch the power curve, drop another perpendicular from that to the airspeed line and hey presto, there is the airspeed at which max angle of sustained climb can be performed, or a max perf T/O. On the ’47 it will be almost exactly 25 knots.

The technique is to set the aircraft at the 25 knots attitude immediately as you take off and keep it there whilst smoothly pulling through to full power. The trees will need to be someway under you rotor disc while still on the ground with disc level. Much supervised practice is required before solo at it.

Just don’t forget that when your boss quotes on a job to shift big mobs of junk in such manner, makes sure that he demonstrates to you first how much weight he reckoned you could carry. You both may be surprised.

[Shawn Coyle]

Topendtorque:

One minor point - the speed for maximum range in a turbine helicopter cannot be determined in the manner you describe due to improved specific fuel consumption at higher power settings. For a turbine, fuel flow vs. airspeed is needed. To be really accurate in determining best range airspeed for both piston and turbine machines, you should use a graph of fuel flow vs. Airspeed.
Several textbooks make this mistake (but not mine!)

[topendtorque]

I appreciate that Shawn, and there were some excellent discussions by yourself and Nick re max range speed with turbines fairly recently somewhere close by.

of course the '47 speed will depend on the state of the blades and whether or not the main power port in the carburettor is opening or not. Just under that setting the max range speed must be the best, just over it and fuel disappears like there was no tomorrow, at about 22.5 inches or maybe a bit more. no two carbies are the same.

The reason I pursue the subject is because of the mass emergence of the R44 onto the airwork scene. Although i have not experimented with them in the same way as I have with '47's i suspect that the numbers would be similar.

I accept that there may be some useful difference between the carburetted and the later fuel injected models with the better blades.

Another useful guide on the pre landing power checks was to see what the margins were between IGE hover and full throttle. Five inches usually meant straight up and 3 to 4 inches would be acceptable for a 'max perf' T/O.

OGE hover power checks of course are simple, provided one is smart enough to remember to do them, many are not. one inch spare for climbing at that same weight and one more if one is to be operating close to trees etc where the airflow will be disturbed. don't forget that the air close to the ground may be quite a bit hotter than where the power check is done, meaning that a bit more will be required.

Another tip is one inch in the six cylinder machine usually represents, 10 hp and 100 pounds of weight that can be picked up, vertically, so calculate the power check according to the load to be dropped or picked up.

very simple really, just never pull more than is there.

[delta3]

Topendtorque


Some results from the desktop world:

Simulation of power curve of a R44-I near MTOW at ISA conditions
Calculated output MR HP. To convert this in Engine HP, one needs to add all mechanical losses plus the TR power. At low speeds where the TR needs to produce approx 500N in this scenario torque I think that the max engine HP of 205 allows for approx 165 MR HP (=red horizontal line).

As Shawn pointed out this graph also does not convert to fuel flow so that for optimal economic speeds it is only approximative.


The results are :

http://www.portmyfolio.com/prive/heli/Power%20curve.jpg


Possible interpretations:

Between IGE and OGE there is 23 MR HP difference, what translates to 30 engine HP so 3 inches. To be added to that is a required acceleration which probably adds 1 inch. This leads to 4 inches. I took 3 ft as IGE instead of 0ft this could explain the difference of 1 inch.

With respect to MP take off the max setting allows for 300 ft/min from 10-15 knts onwards, but again probably one inch margin is needed which translates to a 15-20 knts range.

Does that make any sense ?

d3

[hihover]

MD900 - I need some help with your terminology. By "max performance" do you mean max all up mass? Or do you mean lower than max all up mass and using all excess power available for better acceleration/climb?

If you mean the former, then it should be included in all helicopter training courses within JAA Member States and it should be tested on all JAA Helicopter Licence Skills Tests for PPL(H) and CPL(H).

I believe the same requirement exists for FAA tests and I would expect it to be an ICAO requirement.

The graph that topend describes is simply the power curve and its significant values are also an ICAO requirement that ALL helicopter pilots should know.

Incidentally, topend - you might like to look at your 3rd conclusion. I would say that the speed is the "best angle of climb at low speed". This speed would normally be used to clear the closest obstacles after transition to forward flight. Maximum angle of climb is 90 degrees without a power limit. You are quite right, however, judgement of the space required to get it right can be tricky.

tam

[delta3]

Maximum slope


By rearranging the data of the previous graph for different speed/climb rates at a given load and power setting the following graph shows up:

http://www.portmyfolio.com/prive/heli/Slope.jpg

Assumptions are (using data from previous plot) : 165 HP MR power available, loaded near MTOW, which means just enough for a high hover, but not enough for a vertical climb.

The curve shows a S-shape. Drawing a tangent shows that in this configuration 15 kts gives the steepest slope.


In order to start from IGE building up of speed towards 15 knts a lower initial climb rate would be used and hence a flatter initial path. In order to compute the detailed acceleration strategy and resulting distance some more calculations would be necessary.


As a pilot I would of course also take aborting options into consideration when determining the acceleration.


d3