Albuquerque, NM USA--Crash
Join Date: Nov 2008
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The twist grip is used in the event of a primary engine control malfunction.
Join Date: Mar 2005
Location: Holly Beach, Louisiana
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Can a 350 power lever (engine speed control) or whatever the thing is called, be used to reduce Rotor RPM during Tail Rotor Emergencies? I understand it would require the use of the Collective Hand to make that movement but then so did the S-76, BK, BO for that matter.
After all it is an emergency situation is it not?
After all it is an emergency situation is it not?
Join Date: Aug 2013
Location: USA
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B3 differences
You need to differentiate between B3 models. There are three different engines as the aircraft has developed. The 2B used the single channel Fadec the Off/Idle/Fly Fadec switch with manual control of the engine via twist grip if there was a Fadec failure. The 2B1 introduced a dual channel Fadec with mechanical back up and an Off/On switch with idle and flight controlled by twist grip positions. The 2B1 models also offered the IGW to 5250 if equipped with dual hyd. The newest B3, marketed as the "B3e" but still certified as a B3, offers the 2D engine with the same IGW with dual Hydraulics, same Off/On switch with idle/flight controlled by the two position twist grip, dual channel Fadec with mechanical backup, an improved Fadec, longer MCP of 30 min and an eventual engine TBO 0f 6,000 hrs (4,000 as of now). With the dual channel versions there is no "manual" control. If both independent Fadec channels fail, there is a mechanical back up but no manual backup. I'm not a 10,000 hr guy but have time in all three versions and the emergency procedures are significantly different between the 2b and the 2B1/2D as far as fuel control/Fadec failures.
The B2's do not have Fadec and the vast majority are equipped with a fuel flow control (FFC) mounted on the floor. A twist grip is available as a factory option although not very common and very pricey. With the twist grip option, the start is completely manually modulated similar to RR C30 in the 206Ls and MD530s. On the newest B2's, there is an "idle stop" incorporated in the throttle quadrant (emergency shutoff, rotor brake, FFC). Up until 2013, this was not offered and there was no "idle stop", you had to watch Ng to know where idle was (67-70% Ng) and, in emergency procedures/auto rotation training, make sure not to move it too far to the rear as to cause a shutdown. In a hover, a tail rotor failure in a B2 with a FFC would be very sporty. Letting go of the collective to grab the FFC, pull it out of the detent, shut the engine down and then grab the collective again to cushion the landing all while you are trying to keep the thing from spinning too fast before the skids contact the ground and you roll over? I would guess the "average" pilot couldn't do it all in the real deal, myself included, especially when you figure in the time to recognize the actual problem as you start to spin. In training you are expecting it but of course you are not in real life.
Regards.
The B2's do not have Fadec and the vast majority are equipped with a fuel flow control (FFC) mounted on the floor. A twist grip is available as a factory option although not very common and very pricey. With the twist grip option, the start is completely manually modulated similar to RR C30 in the 206Ls and MD530s. On the newest B2's, there is an "idle stop" incorporated in the throttle quadrant (emergency shutoff, rotor brake, FFC). Up until 2013, this was not offered and there was no "idle stop", you had to watch Ng to know where idle was (67-70% Ng) and, in emergency procedures/auto rotation training, make sure not to move it too far to the rear as to cause a shutdown. In a hover, a tail rotor failure in a B2 with a FFC would be very sporty. Letting go of the collective to grab the FFC, pull it out of the detent, shut the engine down and then grab the collective again to cushion the landing all while you are trying to keep the thing from spinning too fast before the skids contact the ground and you roll over? I would guess the "average" pilot couldn't do it all in the real deal, myself included, especially when you figure in the time to recognize the actual problem as you start to spin. In training you are expecting it but of course you are not in real life.
Regards.
Speed select in the overhead/on the floor, single pilot?
Dump the lever. No quibble, no playing, just dump the lever and take off the torque. Fly the helicopter. Then debate whether you will fiddle around with the fuel control or not.
Dump the lever. No quibble, no playing, just dump the lever and take off the torque. Fly the helicopter. Then debate whether you will fiddle around with the fuel control or not.
Join Date: Aug 2013
Location: USA
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Yes, collective mounted cut off/yaw servo test switch for the dual hydraulics.
And I agree with you Mr. Eacott, that's about the best option in my humble opinion. I think pulling the FFC off is a bit unrealistic. Hopefully you drop it and get it back on the ground prior to the rotation becoming to great and causing it to roll over. Going to have to be quick! I have discussed this with several pilots whose opinion I respect and it was pretty much agreed the hardest part is getting past the "Oh sh**, whats happening!" second or two time delay.
And I agree with you Mr. Eacott, that's about the best option in my humble opinion. I think pulling the FFC off is a bit unrealistic. Hopefully you drop it and get it back on the ground prior to the rotation becoming to great and causing it to roll over. Going to have to be quick! I have discussed this with several pilots whose opinion I respect and it was pretty much agreed the hardest part is getting past the "Oh sh**, whats happening!" second or two time delay.
"Just a pilot"
In the Aerospatiale, er- Eurocopter, no- Airbus helicopters without a twist grip engine control, collective down is your only option. It's a tough decision that has to be made quickly in a demanding situation, especially if you don't have an expansive area to land. It will land hard, you can't grease this one on, and accurate placement of the skids is more hand grenade than pistol, pretty much the exact opposite of every flight maneuver one has initiated.
If anti-torque control was the issue and rotation nose left/pedals unresponsive make it sound so, at least this one stayed on the roof, everybody survived and no bystanders were involved.
If anti-torque control was the issue and rotation nose left/pedals unresponsive make it sound so, at least this one stayed on the roof, everybody survived and no bystanders were involved.
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Having survived a tail rotor failure in the IGE hover, I can attest that slamming the lever down is pretty much all you've got time to do. That was a Lynx with ECLs in the roof, we went through 270 degrees from 4 feet to the ground in around a second, and the NHP got the throttles un-gated and back after we touched down.
Slow and easy every time you pick it up will prevent this. I know I'm preaching to the choir, but I really can't see any reason for this type of accident. As soon as the nose started to yaw he should have put the collective down. Very similar to the roll over accidents where a skid is hung up and the pilot tries to snatch it into the air.
