Helicopter crash Mexico

[melax]

Oh Boy, the minibus driver escaped twice ! once , the rear getting hit and then el conductor (a) must have pressed the gas pedal so hard.... to escape this time around the tail Rotor ! The pickup guy also got so afortunado !
A lots of ropa interior changes

Good job by the Pilot tho.

 

[NovemberEcho]

I’m still blown away every time I learn Mexico has a navy

 

[Skåning]

Oh Boy, the minibus driver escaped twice ! once , the rear getting hit and then el conductor (a) must have pressed the gas pedal so hard....

I like how the guys in the black pickup have a front row seat and only move after the helo stops. Definitely have some caca in your shorts after that

 

[derg]

I’m still blown away every time I learn Mexico has a navy

Right by the Delta gates at MEX!

 

[MikeD]

Classic unanticipated left yaw in a clockwise (eurotrash) rotating main rotor system, when slow and making a left turn, especially with any tail wind. If it is at all hot and/or high, with a resultant high DA, the effects of this are more abrupt and longer lasting, and recovery from this with full right pedal will take longer or may not have the available power to do so if near the engine or transmission performance limits in temp, DA, etc. Increasing power demand in an attempt to arrest the descent rate, only increases the anti-torque demand of the tail rotor, which already isn’t aerodynamically able to provide enough anti-torque to get back to the “trim curve”. The tail rotor is demanding more power than the engine/transmission can give, so if rotor RPM droop begins happening, as power settling begins. It’s one of those aerodynamic phenomena where once you get into it and either don’t recognize it quickly and don’t rectify it quickly (and don’t have the altitude below you to do so), will become a tightening square corner that you won’t be able to get out of.

 

[Cherokee_Cruiser]

Classic unanticipated left yaw in a clockwise (eurotrash) rotating main rotor system, when slow and making a left turn, especially with any tail wind. If it is at all hot and/or high, with a resultant high DA, the effects of this are more abrupt and longer lasting, and recovery from this with full right pedal will take longer or may not have the available power to do so if near the engine or transmission performance limits in temp, DA, etc. Increasing power demand in an attempt to arrest the descent rate, only increases the anti-torque demand of the tail rotor, which already isn’t aerodynamically able to provide enough anti-torque to get back to the “trim curve”. The tail rotor is demanding more power than the engine/transmission can give, so it rotor RPM droop begins happening, as power settling begins. It’s one of those aerodynamic phenomena where once you get into it and either don’t recognize it quickly and don’t rectify it quickly (and don’t have the altitude below you to do so), will become a tightening square corner that you won’t be able to get out of.

I don’t understand helicopter black magic, voodoo, wickedness.

So this wasn’t some emergency crash landing. What could they have done to prevent it? And any way to just bail out of this situation and climb out?

 

[Cherokee_Cruiser]

Oh Boy, the minibus driver escaped twice ! once , the rear getting hit and then el conductor (a) must have pressed the gas pedal so hard.... to escape this time around the tail Rotor ! The pickup guy also got so afortunado !
A lots of ropa interior changes

Good job by the Pilot tho.

I like how there are multiple pieces of flying blades going airborne and the guys be like, hold on bro Ima rekord this on my phone…

 

[melax]

Classic unanticipated left yaw in a clockwise (eurotrash) rotating main rotor system, when slow and making a left turn, especially with any tail wind. If it is at all hot and/or high, with a resultant high DA, the effects of this are more abrupt and longer lasting, and recovery from this with full right pedal will take longer or may not have the available power to do so if near the engine or transmission performance limits in temp, DA, etc. Increasing power demand in an attempt to arrest the descent rate, only increases the anti-torque demand of the tail rotor, which already isn’t aerodynamically able to provide enough anti-torque to get back to the “trim curve”. The tail rotor is demanding more power than the engine/transmission can give, so it rotor RPM droop begins happening, as power settling begins. It’s one of those aerodynamic phenomena where once you get into it and either don’t recognize it quickly and don’t rectify it quickly (and don’t have the altitude below you to do so), will become a tightening square corner that you won’t be able to get out of.

Hey MikeD, what do you mean by "Eurotrash" ? Airbus, Agusta Westland ?

This Heli seems to be Ruski type (MI-17), is it the same rotation pattern ? Also the elevation of the crash site is about 7,000ft and average temp 70F.
It seems to be an engine failure of some kind decreasing the power output of the engine (s) ?
Or Tail Rotor lack of authority ( TR transmission failure) ?
It looks like the pilot picked up the emergency landing site with accuracy avoiding the houses.
I remember one going down in West Africa a couple of years ago under similar conditions in Senegal, but with a different outcome as they had to ditch it and sustained casualties. The Temp there was around 90F Sea level.

 

[Richman]

I don’t understand helicopter black magic, voodoo, wickedness.

So this wasn’t some emergency crash landing. What could they have done to prevent it? And any way to just bail out of this situation and climb out?

I used to think that Laura Dern was somewhat cute-ish, but I have since re-evaluated.

 

[MikeD]

Hey MikeD, what do you mean by "Eurotrash" ? Airbus, Agusta Westland ?

This Heli seems to be Ruski type (MI-17), is it the same rotation pattern ? Also the elevation of the crash site is about 7,000ft and average temp 70F.
It seems to be an engine failure of some kind decreasing the power output of the engine (s) ?
Or Tail Rotor lack of authority ( TR transmission failure) ?
It looks like the pilot picked up the emergency landing site with accuracy avoiding the houses.
I remember one going down in West Africa a couple of years ago under similar conditions in Senegal, but with a different outcome as they had to ditch it and sustained casualties. The Temp there was around 90F Sea level.

hot and high, high DA.

European helos have a clockwise rotating main rotor system, hence the phenomena I discussed. It’s opposite with US helos that have a counter-clockwise rotating main rotor system……tight/slow/quick right turns in the same conditions become problematic.

full anti-torque (right) pedal is what he needed, along with a power reduction to reduce torque being created and thus, less anti-torque required to arrest the left rotation. Problem is, the longer that uncommanded yaw is allowed to develop….every second that goes by…..the longer corrective anti-torque pedal will need to be input to correct and regain nose control back to trim. And for the second part, power reduction, since this usually occurs close to the ground (tight decelerating turns); any power reduction to decrease torque, results in a descent…..which at low altitude, theres often not enough altitude above the ground to arrest the problem before impact.

 

[CFI A&P]

I don’t understand helicopter black magic, voodoo, wickedness.

So this wasn’t some emergency crash landing. What could they have done to prevent it? And any way to just bail out of this situation and climb out?

I’m not a rotorcraft pilot either, but from what I understand this is the equivalent of being behind the power curve from several different angles and at some point you’re just hanging on for the ride.

 

[Beep]

I don’t understand helicopter black magic, voodoo, wickedness.

So this wasn’t some emergency crash landing. What could they have done to prevent it? And any way to just bail out of this situation and climb out?

They could have been fixed wing pilots instead, that would have dramatically decreased their chances of crashing a helicopter.

 

[Low_Level_Hell]

The Germans built their helicopters (Messerschmitt) the right way with counter clockwise rotation like the American helos. It was the French that messed it up with the Eurocopter/Aerospatiale line. Coincidentally all those companies are now merged under Airbus.

 

[melax]

hot and high, high DA.

European helos have a clockwise rotating main rotor system, hence the phenomena I discussed. It’s opposite with US helos that have a counter-clockwise rotating main rotor system……tight/slow/quick right turns in the same conditions become problematic.

full anti-torque (right) pedal is what he needed, along with a power reduction to reduce torque being created and thus, less anti-torque required to arrest the left rotation. Problem is, the longer that uncommanded yaw is allowed to develop….every second that goes by…..the longer corrective anti-torque pedal will need to be input to correct and regain nose control back to trim. And for the second part, power reduction, since this usually occurs close to the ground (tight decelerating turns); any power reduction to decrease torque, results in a descent…..which at low altitude, theres often not enough altitude above the ground to arrest the problem before impact.

Wouldn't this phenomena you're describing occurring regardless or the direction of rotation ? i.e in reverse (counter clockwise) ? requiring left foot anti-torque input then, yielding the same control effect ?

 

[MikeD]

Wouldn't this phenomena you're describing occurring regardless or the direction of rotation ? i.e in reverse (counter clockwise) ? requiring left foot anti-torque input then, yielding the same control effect ?

If you lose anti-torque effectiveness, the fuselage turns/yaws in the torque direction since the torque present, begins to exceeds anti-torque available. A euro helo will spin left, a US helo will spin right, in this condition.

In the opposite direction scenario (had this been a right turn)……you have a longer time for any loss of aerodynamic tailrotor effectiveness…..literally a long time, as the main rotor torque is counter to the turn direction, requiring much less pedal input to the tail rotor, because the main rotor system is helping you out.

 

[MikeD]

The Germans built their helicopters (Messerschmitt) the right way with counter clockwise rotation like the American helos. It was the French that messed it up with the Eurocopter/Aerospatiale line. Coincidentally all those companies are now merged under Airbus.

And MBB’s BO-105 had a fully rigid main rotor system. A bit if a rougher ride, but solid.

I’m not a big fan of Aerospatiale/Airbus, even though I’m in those most. I don’t even like tail rotors. Nice tail rotor light helo? AW119….now Leonardo. But I’ll take NOTAR any day with an MD-520/600.

 

[DropTank]

This wasn't a mechanical failure?
But a design limitation?

 

[MikeD]

This wasn't a mechanical failure?
But a design limitation?

doesn’t appear to be mechanical. However it’s not a design limitation, it’s a very common aerodynamic phenomenon. All helos with tail antitorque system, are susceptible.

 

[melax]

If you lose anti-torque effectiveness, the fuselage turns/yaws in the torque direction since the torque present, begins to exceeds anti-torque available. A euro helo will spin left, a US helo will spin right, in this condition.

In the opposite direction scenario (had this been a right turn)……you have a longer time for any loss of aerodynamic tailrotor effectiveness…..literally a long time, as the main rotor torque is counter to the turn direction, requiring much less pedal input to the tail rotor, because the main rotor system is helping you out.

Ok I'm not a rotary guy, so I have limited practical knowledge, but I was under the impression that it didn't matter, that it was more a consideration pertaining to engine selection (elimination of gearing etc. due to engine rotational direction) and that the TR rotation in relation to the MR (down wash vs up wash) was more of a consideration. So when I have a spare moment I'm going to look into this stuff and bother my Helicopter buddies...
Thanks MikeD.

 

[MikeD]

Ok I'm not a rotary guy, so I have limited practical knowledge, but I was under the impression that it didn't matter, that it was more a consideration pertaining to engine selection (elimination of gearing etc. due to engine rotational direction) and that the TR rotation in relation to the MR (down wash vs up wash) was more of a consideration. So when I have a spare moment I'm going to look into this stuff and bother my Helicopter buddies...
Thanks MikeD.

depending on the rotor system rotation direction on a single-rotor system helo, the torque is in the opposite direction, due to Newtons 3rd law. The tail rotor acts horizontally to counter the torque, either as a pusher or a puller, depending on which side of the tail it’s mounted on.

Luckily, most Kamans, all chinooks and Sea Knights, with their counter-rotating main rotor blades, don’t have to worry about any of this pain in the ass stuff.