AW139 Crash in Bahamas - 7 Killed
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I’ve not flown the 139, but other automated types I have will keep the heading very accurately if you keep your feet off the pedal micro switches, and typically do so even with some bank applied below a certain IAS, above which they revert to coordinated turn mode. It’s not even a function of the automation - it’s a fairly basic ATT mode AFCS function.
Assessing a candidate on a PPC/LPC in the Level D simulator for an instrument departure requires they maintain runway heading +/- 5 degrees until VY under EASA, TC, FAA and the CAA.
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Been following this with an especially high degree of interest as an ex 139 driver (1400hrs), currently SPIFR on a VIP 76 C+ flying almost the exact mission profiles this machine does, in precisely the same part of the world with a remarkably similar client.
In fact, this bird passed by my condo along the coast on many occasions and we often found each other at the same FBO awaiting fuel.
Our missions include 'lunches in Bimini and dinners in Treasure Cay' on an infrequent basis, often returning to FLL at night...
This accident is particularly poignant.
When I first saw the wreckage underwater with the gear still extended and learned 12 hours had passed before anyone started taking notice, it made me question as to what kind of operation were they running that no one was looking for this bird before noon the next day?
Seemed to me, he was doing what he was paid to do....Nothing really out of the ordinary there, at least not for anyone with experience going off rigs at night...but I'll hold off further conjecture and wait till the autopsy of the pilot is known....
In fact, this bird passed by my condo along the coast on many occasions and we often found each other at the same FBO awaiting fuel.
Our missions include 'lunches in Bimini and dinners in Treasure Cay' on an infrequent basis, often returning to FLL at night...
This accident is particularly poignant.
When I first saw the wreckage underwater with the gear still extended and learned 12 hours had passed before anyone started taking notice, it made me question as to what kind of operation were they running that no one was looking for this bird before noon the next day?
Seemed to me, he was doing what he was paid to do....Nothing really out of the ordinary there, at least not for anyone with experience going off rigs at night...but I'll hold off further conjecture and wait till the autopsy of the pilot is known....
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n. maintain the desired heading within ±10° and the desired airspeed/V-speed within +10/-5 knots or the appropriate Vspeed range.
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Been following this with an especially high degree of interest as an ex 139 driver (1400hrs), currently SPIFR on a VIP 76 C+ flying almost the exact mission profiles this machine does, in precisely the same part of the world with a remarkably similar client.
In fact, this bird passed by my condo along the coast on many occasions and we often found each other at the same FBO awaiting fuel.
Our missions include 'lunches in Bimini and dinners in Treasure Cay' on an infrequent basis, often returning to FLL at night...
This accident is particularly poignant.
When I first saw the wreckage underwater with the gear still extended and learned 12 hours had passed before anyone started taking notice, it made me question as to what kind of operation were they running that no one was looking for this bird before noon the next day?
Seemed to me, he was doing what he was paid to do....Nothing really out of the ordinary there, at least not for anyone with experience going off rigs at night...but I'll hold off further conjecture and wait till the autopsy of the pilot is known....
In fact, this bird passed by my condo along the coast on many occasions and we often found each other at the same FBO awaiting fuel.
Our missions include 'lunches in Bimini and dinners in Treasure Cay' on an infrequent basis, often returning to FLL at night...
This accident is particularly poignant.
When I first saw the wreckage underwater with the gear still extended and learned 12 hours had passed before anyone started taking notice, it made me question as to what kind of operation were they running that no one was looking for this bird before noon the next day?
Seemed to me, he was doing what he was paid to do....Nothing really out of the ordinary there, at least not for anyone with experience going off rigs at night...but I'll hold off further conjecture and wait till the autopsy of the pilot is known....
The premiums were astronomical if we didnt fly dual pilots with 6 month recurrancy at FSI.
I’ve not flown the 139, but other automated types I have will keep the heading very accurately if you keep your feet off the pedal micro switches
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Transport Canada Flight Test Guide: https://www.tc.gc.ca/media/documents...g/tp14728e.pdf
n. maintain the desired heading within ±10° and the desired airspeed/V-speed within +10/-5 knots or the appropriate Vspeed range.
n. maintain the desired heading within ±10° and the desired airspeed/V-speed within +10/-5 knots or the appropriate Vspeed range.
Hi Outwest,
The link to that that guide you posted was the first edition for TC in 2007. They were working off an edition dated from 2011 the last time I did a TC ride. The regs at that time required +/-10 degrees on any assigned heading during the departure. This applied to the assigned heading in your ATC clearance once the aircraft was up and flying.
For the initial part of the takeoff the tolerances were tighter though at +/-5 degrees. If you rotated from the center of the runway in 600 RVR or VFR conditions and immediately took up a heading 10 degrees off of the runway you’d be over the infield dodging taxiing aircraft before you hit VY.
It’s been a few years since I’ve done TC checkrides but I assure you the EASA checkrides and FAA checkrides that were done a few months ago were to +/- 5 degrees on the initial part of the departure.
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I’ve not flown the 139, but other automated types I have will keep the heading very accurately if you keep your feet off the pedal micro switches, and typically do so even with some bank applied below a certain IAS, above which they revert to coordinated turn mode. It’s not even a function of the automation - it’s a fairly basic ATT mode AFCS function.
You are correct with the 139 as well. The aircraft uses yaw to maintain heading below 40 knots and roll to maintain heading above. It will maintain a coordinated turn no problems at those higher speeds. The aircraft will also maintain its heading in the hover very accurately with your feet off the pedals and on the floor.
The micro switches are very sensitive in the AW139 and the pedals lack the outer “horns” several other aircraft utilize to rest your feet on keeping them off these micro switches. The only option left in the AW139 is the floor where the majority of the pilots I’ve flown with place their feet while flying on instruments or VFR, coupled or uncoupled at speeds above 40 knots.
However, during a helipad or helideck departure I have yet to see a single person take their feet off the pedals and place them on the floor. Deck edge turbulence and collective power changes are just a few of the things that could require the input of pedal at yaw rates greater than the automation can provide.
There is also the requirement to be hands on and flying attentively during the hover and initial departure which I believe doesn’t include placing your feet on the floor as you rotate.
Last edited by RL77CHC; 17th Jul 2019 at 05:48.
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The technique taught by the USN when we trained on the H-34 in basic for an instrument take off. Once lifted into the hover feet were taken off the pedals, take off performed, feet returned to pedals when established in the climb. Anybody actually use this technique in the civil world?
I’ve had just the opposite demonstrated in training in Italy, Malaysia and Jersey and subsequently have always trained the opposite in the aircraft.
We pick up the aircraft with our feet on the pedals. Do the hover checks with our feet on the pedals. Rotate with our feet on the pedals. Take our feet off the pedals and place them on the floor when the airspeed hits 40 knots. When decelerating keep our feet on the floor until the airspeed hits 40 and then place them on the pedals.
That seems odd that you were trained to use the heading hold feature in the hover and departure but then placed your feet back on the pedals essentially “turning off” the system with the depressed micro switches when you were established in the climb.
There’s no way the yaw control would have the response time to be able to accurately hold runway heading on a CAT A clear field departure in gusty crosswinds on the AW139. We’ve tried it before a decade ago when we were new on the aircraft and it just didn’t work.
However, at speeds above 40 knots it was so solid maintaining coordinated turns and heading there was no need to keep your feet on the pedals. Tough habits to train out of old dogs like myself.
Love the H34 by the way!
Last edited by RL77CHC; 17th Jul 2019 at 06:07.
That seems odd
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RL, I'm going back 51 years so the memory cells are a little corrupted. I don't recall the level of sophistication of the H-34 system, in the 70 hour course you never flew it hands off and don't recall if the aircraft even had the capability. Had SAS is about all I recall.
Gee guys...my memory is absolutely clear...so long as it is not about something five minutes in the past.
My very limited memory of the 34 tells me it had Altitude hold and Attitude hold.
I do for sure recall opening the cabin door while the BarAlt Hold was on....produced some interesting reactions by the autopilot....as it was vented/sensed the air pressure inside the cabin area.
As to modern autopilots being able to do a Cat A takeoff.....I suggest we bin the Cat A thing altogether for IMC Takeoffs and simplify the procedure.
Engine failures have become a fairly uncommon occurrence....and just as in our training we pay far too much attention and time to that particular kind of failure.
I know my kind of thinking runs counter to established concepts.....but as far back in my S-58T days....I thought the procedures just plain goofy.
Weight management and knowing what your single engine performance is makes far more sense to me.
Either the aircraft will fly on one engine or it will not....knowing that facilitates knowing whether to continue the takeoff or not.
I see CAT A profiles as being far too cumbersome for the amount of exposure......one man's opinion here.
I said this back during the Gillingham Crash discussion.
Had that crew used something akin to the old style Military ITO....that crash would not have happened.
We do not know what kind of Takeoff Profile the Bahama's crash crew used so we cannot compare the two.
My very limited memory of the 34 tells me it had Altitude hold and Attitude hold.
I do for sure recall opening the cabin door while the BarAlt Hold was on....produced some interesting reactions by the autopilot....as it was vented/sensed the air pressure inside the cabin area.
As to modern autopilots being able to do a Cat A takeoff.....I suggest we bin the Cat A thing altogether for IMC Takeoffs and simplify the procedure.
Engine failures have become a fairly uncommon occurrence....and just as in our training we pay far too much attention and time to that particular kind of failure.
I know my kind of thinking runs counter to established concepts.....but as far back in my S-58T days....I thought the procedures just plain goofy.
Weight management and knowing what your single engine performance is makes far more sense to me.
Either the aircraft will fly on one engine or it will not....knowing that facilitates knowing whether to continue the takeoff or not.
I see CAT A profiles as being far too cumbersome for the amount of exposure......one man's opinion here.
I said this back during the Gillingham Crash discussion.
Had that crew used something akin to the old style Military ITO....that crash would not have happened.
We do not know what kind of Takeoff Profile the Bahama's crash crew used so we cannot compare the two.
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Hi Outwest,
The link to that that guide you posted was the first edition for TC in 2007. They were working off an edition dated from 2011 the last time I did a TC ride. The regs at that time required +/-10 degrees on any assigned heading during the departure. This applied to the assigned heading in your ATC clearance once the aircraft was up and flying.
For the initial part of the takeoff the tolerances were tighter though at +/-5 degrees. If you rotated from the center of the runway in 600 RVR or VFR conditions and immediately took up a heading 10 degrees off of the runway you’d be over the infield dodging taxiing aircraft before you hit VY.
It’s been a few years since I’ve done TC checkrides but I assure you the EASA checkrides and FAA checkrides that were done a few months ago were to +/- 5 degrees on the initial part of the departure.
How many times must you actually throw switches and such for an engine failure?
In the Bell 212/412 Sim I watched crews kill themselves doing just as you describe when in reality....they could have carried on and returned for a safe landing having touched nothing.
I referred to the "Dipped Shoulder Syndrome"....Caution Light illuminates along with a Master Caution....and immediately one crew member reaches for the Emergency checklist.
That to me is very bad Karma or bad JuJu....and signals a great failure to "Think" first and act later.
I also opined often that the Crew should take "Immediate Action"....reset the Master Caution and start the Clock.....then carefully consider what they are seeing.
That way their urge to do something is answered....but they did nothing that would harm them or make the situation worse than it is.
Of course there are certain malfunctions that do require some immediate reactions but they are few and fortunately very rare.
Generally, none require much in the way of switch moving.
We have to face reality....most helicopters are not that complex as compared to some large airplanes when it comes to systems control.
So why do we make things difficult when they could be a lot simpler?
I personally believe if you have to refer to a checklist to operate a helicopter....you might just be in the wrong business.
Checklists are supposed to be aids....not rituals that must be worshipped.
In the Bell 212/412 Sim I watched crews kill themselves doing just as you describe when in reality....they could have carried on and returned for a safe landing having touched nothing.
I referred to the "Dipped Shoulder Syndrome"....Caution Light illuminates along with a Master Caution....and immediately one crew member reaches for the Emergency checklist.
That to me is very bad Karma or bad JuJu....and signals a great failure to "Think" first and act later.
I also opined often that the Crew should take "Immediate Action"....reset the Master Caution and start the Clock.....then carefully consider what they are seeing.
That way their urge to do something is answered....but they did nothing that would harm them or make the situation worse than it is.
Of course there are certain malfunctions that do require some immediate reactions but they are few and fortunately very rare.
Generally, none require much in the way of switch moving.
We have to face reality....most helicopters are not that complex as compared to some large airplanes when it comes to systems control.
So why do we make things difficult when they could be a lot simpler?
I personally believe if you have to refer to a checklist to operate a helicopter....you might just be in the wrong business.
Checklists are supposed to be aids....not rituals that must be worshipped.
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RL, I'm going back 51 years so the memory cells are a little corrupted. I don't recall the level of sophistication of the H-34 system, in the 70 hour course you never flew it hands off and don't recall if the aircraft even had the capability. Had SAS is about all I recall.
RL77 ,surely the first part of the instrument t/o is `track`oriented,and not heading,until you are established in the climb...ie if you have a x-wind ,you must change heading to fly the track....
