Lessons for young players

[Steve76]

Read this and then tell me if/why you would opt for the LH turn at the top of your ascent?
Not wanting to slag this pilot, Lord knows I have got away with worse - I am just using this as an example. Hey! **** happens to everyone and he probably was told to do this at a flight school somewhere; but if I was asked which way I would turn the answer would be RH in this aircraft or a 'powered' turn in whatever type.
IF you have to unload the TR to turn then you will definitely require more power to arrest that turn or to straighten into wind, that you obviously do not have available. At the top of your ascent and far from the effects of your ground cushion (the little you have on a tree covered slope) your power requirement is going to be substantially more and the direction control is going to require an over torque, over-temp and as this example shows cause settling with power.
You don't need the physics or to define this via principles of flight – this is a golden rule (as far as I am concerned) if I need to turn, I always make it powered. Better to work with what you have, than hope for a collection of variables (wind, translation, sloping ground etc) coming to fruition.
What do the other 'experienced' guys think about what I have said?
At 2020 Pacific daylight time, the pilot of the Eurocopter AS350 B2 (Astar) helicopter landed on a recently prepared mountainside helipad, at 5200 feet elevation. With the helicopter still running at flying rotor rpm and light on the skids, four passengers boarded with a small amount of personal equipment and prepared for take-off. The pilot increased collective pitch to bring the helicopter into the hover, but the engine parameters were approaching their limits, and he discontinued the take-off and lowered the collective. The left rear passenger got out, and the pilot again raised the collective, lifting the helicopter into a stable five-foot hover over the pad. Satisfied this time with the engine readings, the pilot increased collective pitch and climbed to approximately 20 feet while purposely allowing the nose to swing to the left to turn downhill for the transition into forward flight.
As the helicopter turned through 100 degrees of left turn, the low rotor rpm warning horn sounded and the pilot decided to return to the pad. He allowed the left turn to continue but, by the time the helicopter returned to the original heading, it had drifted approximately 20 feet downhill from the pad and was still descending. The main rotor blades then struck a large tree stump adjacent to the pad and the helicopter rolled over, coming to rest on its left side, almost inverted. The three passengers quickly escaped from the helicopter, but the pilot delayed his exit to shut down the engine, which had continued to run. After he had secured the engine, fuel valve, and electrical switches, the pilot exited the cockpit. The four occupants received minor injuries, and the helicopter was substantially damaged. The emergency locator transmitter activated automatically at rollover. There was no fire.

[paco]

Wasn't he doing what everybody else does in a Bell, but with the right pedal, to reduce the torque required when picking up a load? Maybe that doesn't work in an AS350 and he didn't realise?

Phil

[g-mady]

Your post is titled "Lessons for young pilots"

Being a "young Pilot", are you warning of the dangers of doing a spot turn when heavily loaded in the direction that does not favour the enginge rpm (takes more power to stop the turn?)

Just to be sure?

MADY

[HillerBee]

AS350 Clockwise rotating, so left pedal turns uses less power. In my opinion he should not have done a vertical descent and HOGE at 20 feet and then make the turn. If he'd first made the turn HIGE he would have had less problems. About the necessity for a vertical ascent you can't say much, without knowing the area/conditions.

[Steve76]

I changed the title to reflect your comments g-mady.
Yeah, I am saying if you are going to have to rotate to depart from the site then do the turn using power rather than unloading power. Plan and use whe you have available, don't go out gambling the whole way. As we like to say 'a bit for Mum and the kids...' up the sleeve.
This site is on a tree lined slope (forestry block) and a spot turn in the hover is not an option. He was maxed out and opted to try and sneak out by unloading the tailrotor with the turn. When he overpitched, he then was in an even worse situation because he had to 'load' the TR to rotate back to align with the hill. The drift was due to an overload of problems he created and unlikely (IMO) due to downflowing air. He just focused on the RRPM problem and drifted off his spot.

[FH1100 Pilot]

The thing is, helicopters are extremely easy to crash, sometimes startlingly so (for those who've done it). Before you know it, you're in the "accident zone," it's too late to stop it and parts start a-flyin'.

Those of us who learned to fly underpowered helicopters (or helicopters with weak tail rotors) would never make a hover-turn in the opposite direction of the power pedal. Medication helps, but I still have not-so-fond memories of Bell 47D's with 200 h.p. Franklins, and early A-model Enstroms. Egad! Just mentioning their names makes me twitch.

Paco refers to a specific advanced technique that some of us do use- and that is to unload the tail rotor during the take-off. This works; if you don't mind being cocked off to the side a little (okay, a lot), you can recover 5% more torque by simply pressing on the right pedal in a Bell. BUT!...(and this is a big butt) it must be done as the ship passes through ETL. If you're not absolutely, positively sure that you'll have some streamline effect, you better not try it.

Because of terrain or other considerations, the hapless pilot in Steve76's example may have only had one option: a left pedal-turn. It's hard to say without being there. He may have been in a precarious position that required immediate, aggressive and knowlegeable action, but he waffled at the last minute and decided to abort when it was already too late. We're left to wonder: Which came first, the right-pedal input to stop the turn, or the decaying MR rpm?

On the other hand, maybe he would have crashed anyway if he had continued the ill-advised take-off. Who knows.

It's my feeling that many of us come extremely close to the edge more often than we're really aware. And while we might think that it's due to our outstanding skill, the difference between us and those who end up in the accident reports owes more to luck or fate or the phase of the moon as anything else.

[MD900 Explorer]

Steve76

Hey there cuzz :ok:

Can i assume here that it was relativly hot and humid and he was fully tanked with fuel?
What were the wind conditions for the day?
Did you say mountainside...steep or just very hilly?
Can i assume also that the pilot was within c of g at the time of take off, or this wasnt calculated?
Just wondering, as this bird has a lot of power and it must have been some of a few additional factors me thinks.

waiting for the onslaught.

MD :suspect:

[Steve76]

Hey my Scandinavian brother :)
Sorry to be a stranger - been all over the planet lately. I got your mail and congrats are in order!
What you read is what you get. Yah - I agree that is a machine with a lot of power so he must've been pretty heavy. Dunno about the slope but it doesn't matter. The issue is the turn - what would you do?

Great to hear you.

[MD900 Explorer]

Steve76

I agree somewhat with Hillerbee in that doing the turn whilst HIGE, but as you say this is impossible. This pilot then opted for the HOGE approach, and seems like he turned downwind. This seems to not have helped, coupled with some over pitching, has not helped. Perhaps he flew a Bell product earlier in the day and got confused? Perhaps he encountered some LTE and then managed to correct it, but was then in the ****...who knows.

IMO the route i would have taken would be the HOGE to 20' route but then found the wind once i had cleared the tree tops, got some speed on the nose and then made the turn in an area where a little descent wasn't going to make me hit something; i.e a max performance take off. Failing that i would have unloaded some more gear out of the machine and done a couple of trips.

As you say, have a little spare power. But the answer to your question is that i would have turned with power pedal.

MD :ok:

[flyingtonka]

The B2 has plenty of power, it must have been four cake eating pax and a very hot day.

This is the best guess scenario I came up with that PERHAPS put the pilot in a bit of bother:

The wind was blowing upslope and the pilot approached with either a left or right crosswind to the pad. A pedal turn over the pad was done so that the aircraft was in nose first allowing pax unhindered access from the front.

This would now require a departure of: either a left 180 or right 180 pedal turn over the pad to face down slope and into wind. Now at 5200 feet and heavy pax the pilot thought of unloading the tail and opted for a left turn.

As the aircraft turned it presented its tail to a left upslope crosswind which accelerated the rate of turn.

Now more right pedal is required to arrest the rate of turn, pilot pulls a little more power, rotor droops, low rpm horn sounds, a little more "reactionary" power is applied, and now were settling back toward the ground.

What would I do? Land crosswind, shut down, load pax, start up, light on skids, power check, hover, power check, turn out to the right at 45 degrees terrain permitting.

[i4iq]

As a "young player" or more accurately, a low-hour pilot, I've always been taught to use a "powered" turn whenever possible, so I wouldn't necessarily blame it on a "flight school somewhere". Perhaps he'd developed a bad habbit and questioned the need to do a powered turn...

[MSP Aviation]

i've HEARD that it was common "back in the day" for American military pilots to step on the right (non-power) pedal of their bells to hover out of confined areas at or near max gross. this was then was then used in civvie ops as they were flown mostly by ex-Nam pilots.

but in my (little) training, i've been taught to make pedal turns WITH power.

[170']

Hi Steve

I Guess even a simple question can get complicated sometimes? ...

No I wouldn't have opted for the left turn...In general principle!....

But I'd have needed to be there to answer in this specific case...

Is that hazy enough ;)

170'

[Hiro Protagonist]

To add another question... Is it common to get in an overpitching type (Nr drooping) situation while near (above?) max power in AS350's? I ask because I've been flying Astars for about nine months now, and I've had a chance to use the upper yellow arcs a time or two but not extensivly (flying tours - if you find yourself hovering OGE you've done something wrong). I've always had the impression that the engine was ready to produce more power than was allowed...Now I'm not so sure.

The real bummer is that since he had to come back for the one guy left behind, he could have kicked two out and had the power to get away with it. Plus it's always a better feeling to be left on a mountainside with company than all by your lonesome.

[Steve76]

170' - that is perfect, the exact answer we are looking for! I hope since 800 odd persons have read this and only 12 replies; that this is a 'given' for most of us out there and an anomoly. Either way the message is spread eh!!

Hiro! great point, one guy on the ground to be picked up. I never recognised that while reading this. Well done.

[mustering guru]

Steve76!

hey bro you must be bored to wright about that stuff..(yawn)

MG

[movin' on]

Whether he turned left or right, the decision was made. IMHO the basic flaw was to move off/away from the safe landing area before being sure of power margins available.

Just my 2 cents worth.

MO