A Star down

[CROOK]

Speaking from experience, the Astar can be hovered safely without the hydraulics. I don't how ever think that anyone should try it without proper instruction from an experienced instructor. But having done both repeatedly I couldn't recommend a running landing as your best option. I do understand what the flight manual says, but please consider that it doesn't mean it is the best way to do things.

 

I will give another example of flight manuals being not always 100% perfect. Most if not all say you should enter auto and shutdown your engine in the event of a fire (engine fire). I would argue that may not always be the best solution. Why not fly the aircraft to the ground then shutdown? I feel that doing a running landing is making a simple maneuver into a challenging one. Just like turning an engine fire into an autorotation when it may not be necessary.

 

RTC - I would argue that the accidents you are referring too did not happen because pilots where practicing hovering with hydraulics off but ended up in a hover without being prepared while attempting a running landing. If they had been taught too hover and control the A/C in a hover it would have been a nonissue. Please correct me if I am wrong and you have specific knowledge of hovering accidents in the Astar.

 

Airdog - You are correct about the liability. But as a pilot I am more concerned with my safety and the safety of the A/C and its contents.

 

Goldy- Skidding along a runway is fun but may not always be an option. Also consider that some airports have grooved runways that make skidding a very very dangerous feat. In other words, fun in an R-22 on a flat smooth taxi way. Not so fun in an Astar at close to max gross weight on grooved runway.

[Goldy]

Well, I guess I got what I was searching for. There seems to be some difference of opinion when it comes to reactivating hydraulics close to the ground. I agree that most of these training accidents were probably caused by bleeding off too much airspeed and finding yourself approaching a hover with no hydraulics.

 

In that situation I think it would be safer to reactivate hydraulics and deal with the initial overcontrol issues. I wonder if I can ask any of the pilots who were actually involved in these incidents if in hindsight, it would have resulted in a better outcome to kick that switch back on!

[RTC]

Crook your point about the engine fire procedure in the astar manual is a valid one and comes up often around here. I agree with your premise that the flight manuals are not perfect, and that example does reinforce that. Being this is a public forum I will not be citing any specific incidents that I am familiar with.

 

Speaking in broad generalities though I do agree that most of the accidents I am familiar with happened as a result of unintentionally ending up in a hyds off hover and loosing control while attempting to execute a running landing.

 

I would still contend however that the IP just allowed the PF and himself to get too far behind the aircraft and many of those accidents could have been avoided by earlier IP intervention.

 

My question is where would a line pilot go to obtain specialized hyds off astar hover training because I am not aware of a company that is willing to accept the liability if there is an accident due to the prohibition of said maneuver in the flight manual.

[JDHelicopterPilot]

I wouldn't reactivate the HYD low to the ground as suggested. Really it should have never get to that point. It is not hard to keep some speed on the aircraft and do a running landing. The main thing is just keep the brisk walking pace all the way down. Once you lose that speed before touching down the pedals become very difficult to stay on top of and excessive yawing will occur thus leading t0 loss of control.

 

The Astar can be hovered with no HYD boost, it is very difficult. Some of the GOM companies will demonstrate and teach this as they fly Astars offshore and if the HYD fails you may not have the fuel to make it back to land doing 60knts. Doing so though is very hard and some pilots do not have the arm and leg strength needed to overcome the control forces.

[CROOK]

Gom as well as Alaska are two place a pilot can go to receive hydraulics off hover training. As for an IP you might be SOL, since the factory doesn't teach it.

 

JD you are correct that it does take some arm/leg strength to control the astar for a long period of time. Fuel can be an issue as well over long distances. I would like to add that once the hydraulics have been dumped you can speed back up to a reasonable pace and utilize your left knee/leg to make sure you have enough strengh to land once you get to your destination.

[iChris]

Prior to about 1997 these cautions about hovering after loss of hydraulic were not in the RFM (see attached). In fact, I remember the Eurocopter factory training included, hydraulics off pick-ups and landings from a hover and even pedal turns. The point at that time was to show that their AS350 could be handled after a hydraulic pressure loss without issue. The training was excellent and we learned to handle the aircraft without hydraulic assist.

 

However, there continued to be more accidents from practicing loss of hydraulics than caused by actual hydraulic failures, so Eurocopter decided the no-hover/slow run-on landing was the best overall action for the customers and Eurocopter's best option with respect to liability. The hovering cautions went into the RFM and the rest is history.

 

Honestly, at gross weight without hydraulics, hovering the Astar requires a degree of skill developed from recurrent training.

 

The introduction to section 3 (emergency procedures) states:

 

"The procedures outlined in this section deal with the common types of emergencies; however, the actions to be taken in each actual emergency must relate to the complete situation."

 

So, doing what you think is best to meet any real emergency is acceptable.

 

As it is now, practicing AS350 emergency procedures outside the limits of the RFM is unacceptable and really not of necessity. It's something you hope the insurance company or an injured parties attorney doesn't find out about after an accident. However, under special circumstance an enhanced training program maybe warranted.

 

Edited March 7, 2011 by iChris

[airdoggy]

Nice, this thread is becoming very informative and I am enjoying the knowledge and experience that is coming out. I agree with iChris, in the training environment, it would not be wise to train outside of the RFM in regards to emergency procedures. I also agree, in the event of a real emergency, do whatever it takes to safely mitigate the emergency. Obviously, going home at the end of the day is paramount.

 

During training, I teach the Hyd Emergency procedure as dictated by the RFM. In regards to the running landing, at around 10 knots, it really has never been an issue, especially with any amount of headwind. Yaw control, just prior to touchdown, seems to be a key component the pilot under training struggles with. During all the training provided, there really has not been any problem with control, but I'm also ultra sensitive to ensure the pilot under training is not letting the aircraft get to the point of being too slow and begin the yaw struggle. As JD related, it just isn't that hard to terminate with a running landing and aicraft control is good throughout. With that being said, during training, if the aircraft gets to the point of being out of control (for whatever reason, mechanical, inattentive CFI, poor technique, bad day, etc) I still think a valid option is to reactivate the hydraulics. Yeah, your close to the ground and there may be some overcontrolling, but remember you were out of control or on the verge of being out of control prior to making the decision to reactivate the switch. Also, there is not a prohibition in the RFM that prevents you from restoring the hydraulics in flight. I just wonder, if some of the accidents could have been prevented by doing so. In the training I have provided, it has never gotten to the point of me considering to activate the switch, as it has always been a controlled non event. I still brief it, however, I also realize it will be a pretty difficult endeavor in the heat of the moment. No matter what, prevention from getting into that scenario is key.

[iChris]

Hi Goldy,

I could not find anything in the manual that stated not to reengage the hyds when you are low and slow. As you know it will result in a very large change in control forces that can be challenging to counteract in close proximity to the ground. I just don't let the student get that far behind the aircraft.

 

I have not found that to be the case, but what you will have is a reduction in control forces required and elimination of main rotor feedback. In other words, you'll have the return of full hydraulic assist (irreversible hydraulic system). It was designed to be a mild transition. The reason for that was outlined in a TFS document that stated:

 

"During hydraulic pressure replenishing during training the servo-controls are also pressurized simultaneously as the rotor is at nominal speed."

 

Unless you had an actual hydraulic problem that prompted you to turn-off hydraulics in the first place, there's no reason not to turn it back on if needed.

 

Such is stated in the AS350 RFM supplement (hydraulic pressure failure training procedures):

 

"To enable the pilot to restore the hydraulic power system by re-setting cut-off switch to ON during the training exercise should it become necessary."

 

Whether to restore or not is left to the judgment of the pilot, no altitude restrictions.

 

 

 

 

Edited March 3, 2011 by iChris

[airdoggy]

iChris, thanks for posting excerpts from the RFM, the Telex, and offering a brief review of what is presented. It is helping to substantiate some of the techniques that have been presented. Another great reason to lurk in these types of forums.

[RTC]

Thanks for taking the time to post the info from the Telex I had not seen that page before. I stand corrected. Good thread.