N370MM NTSB Final Report

[Jerry 5TJ]

The final report on Dr. Moir's fatal crash in September 2015 has been released.  

AvWeb's Summary: 

 

 

A leaking oxygen hose fitting likely led to the fatal crash of a turbonormalized Mooney M20 Acclaim off the coast of Atlantic City on Sept. 10, 2015. Dr. Michael Moir, a dentist from Gaylord, Michigan, was the only one aboard the aircraft, which flew on autopilot without contact with ATC for more than two hours at 25,000 feet before descending to the ocean near Atlantic City, New Jersey. Moir was on his way to a Mooney owners safety conference and the NTSB speculated he did everything right to ensure a safe flight. He was still wearing his oxygen mask at the time of the crash but the technical fault made it worthless and he likely became hypoxic shortly after reaching altitude, the report says.

Investigators found that a fitting connecting an oxygen line to the regulator on the tank was loose. It may have been missed at an earlier annual and when Moir activated the oxygen system as he climbed to altitude it likely quickly drained the tank. Moir read back a clearance to 25,000 about 16 minutes after he took off and was never heard from after that. Two F-16s were scrambled but the Mooney crashed before their pilots spotted it. The NTSB said the duration of the flight was consistent with the aircraft draining one of the aircraft's two fuel tanks on the flight.

NTSB:  https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20150910X75635&AKey=1&RType=Final&IType=LA

 

 

 

 

[Danb]

Leaking 02 that totally blows, always something 

[gsxrpilot]

Where is the O2 gauge in the Acclaim? In my 252 it's right in the arm rest and very easy to monitor. When I'm up that high I'm monitoring it constantly. But then I know hypoxia can make you think things are fine when they aren't.

[Danb]

It's on the pilots armrest, more likely importantly where was his oximeters located, and was it operational.

[Danb]

This situation which appears was not the fault of the op brings to light a manner so your copilot could get you 02 or to a lower altitude.

Im going to make a copilot's, assuming they are not pilots, checklist of things to do in the advent of my incapacation.

 

Jolie may have some pointers or recommendations 

[gsxrpilot]

17 minutes ago, Danb said:

This situation which appears was not the fault of the op brings to light a manner so your copilot could get you 02 or to a lower altitude.

Im going to make a copilot's, assuming they are not pilots, checklist of things to do in the advent of my incapacation.

One thing I do whether solo or with a copilot, is to have the altitude preselect armed for a lower altitude with a pretty high rate of decent. With that configured, it only takes one button push to send us down to thicker air and level off there.

[Rookie]

There may be some litigation in this case!

[Jerry 5TJ]

In my T210 I carried a portable bottle & used it for the copilot/passenger so they were using a separate O2 system while I used the internal tanks.  

I'm not an advocate of FL flying in unpressurized aircraft.  17,000 is considerably less risky than 25,000   should O2 fail, and you have a much longer time of useful consciousness to detect a fault.  

The TUC tables are likely based on fit 20-30 year old subjects, not 60-somethings like Dr. Moir or me.  

 

[pinerunner]

A personal blood oxygen level meter would have offered a way to catch this. They're apparently not very expensive and fit over your finger. You might even be able to rig one up so it sets off an alarm (Sleep Monitor CMS50FW by Contec) if it goes below a certain level. If I mess with higher altitudes I think I'll get one.

[Piloto]

I am surprised that the FAA has not required an audible low oxygen pressure alarm for certified aircraft. After all the Mooney has a low fuel warning indicator. The oxygen supply to the mask could also be inhibited by a kinked hose and the pilot would not notice it.

José

[MIm20c]

I have to agree with @Piloto a safety light or alarm would be a good requirement for FL flight.  It is very possible most of his 3-5 mins was used up when he reached his assigned altitude. 

[Danb]

1 hour ago, gsxrpilot said:

One thing I do whether solo or with a copilot, is to have the altitude preselect armed for a lower altitude with a pretty high rate of decent. With that configured, it only takes one button push to send us down to thicker air and level off there.

Good idea

[Jerry 5TJ]

58 minutes ago, Piloto said:

I am surprised that the FAA has not required an audible low oxygen pressure alarm for certified aircraft. After all the Mooney has a low fuel warning indicator. The oxygen supply to the mask could also be inhibited by a kinked hose and the pilot would not notice it.

José

Pressurized aircraft have a cabin altitude warning annunciation. 

A "No O2 Flow" light & horn would be good.  

 

 

[PaulM]

Alarms & lights wouldn't help if your delivery tube is kinked.  

This can also happen: https://www.avweb.com/avwebflash/news/NitrogenUsedToFillAircraftOxygenSystems_196776-1.html

You could plug in this sort of device:

http://www.surgivet.com/catalog/anesthesia-accessories/low-oxygen-pressure-alarm.html

 

The flow meter is supposed to be part of your "scan".   I usually make sure that I do the oximeter test at call out altitudes.. 12.5, 14K, 18K,  cruise level off. 

In the end the GFC700 G1000 ESP system is the answer.  If the pilot is not responsive (pushing buttons, turning knobs) , it auto-descends to a lower level, and that still wouldn't have helped for the accidents with CO problems. 

[Danb]

Once the hose on the inlet side of the oximeter came off, I felt real good, checked my 02 level 83, my wife had to put the hose back on, I was uncapable to reattach it.

I now hang the meter so it's in my view, also I check the saturation every 3-4 minutes if above 14,000, and every 6-7 minutes between 8-13,000 ft.

[kortopates]

37 minutes ago, PaulM said:

Alarms & lights wouldn't help if your delivery tube is kinked.  

....

You could plug in this sort of device:

http://www.surgivet.com/catalog/anesthesia-accessories/low-oxygen-pressure-alarm.html

The flow meter is supposed to be part of your "scan".   I usually make sure that I do the oximeter test at call out altitudes.. 12.5, 14K, 18K,  cruise level off. 

...........

A pressure alarm like that is a great idea. Of course the 35psi that this one alarms at is way too high. But I'd have to put a pressure meter on mine to see what psi it is on the ground - when it would be lowest.

But how unfortunate. This is another huge reminder that we are test pilots after annual and this includes the O2 system after any maintenance. I'll assume this plane at least just had his tank hydro tested after annual and how many have had our tanks re-installed with the rigging not right so that the valve no longer shuts off when closed. However, this is the first I have heard of failing to tighten a fitting.   Still though, I am actually surprised at the speed this tank emptied. It was a partial leak of the low pressure circuit and but apparently was a very large leak or maybe had been leaking longer this flight.  

Regardless though,  it underlines the importance of pilots, especially flying solo, to monitor their saturation and to carry an emergency backup O2 supply. I carry this unit in the seat pocket making it very accessible: http://www.mhoxygen.com/index.php/portable-constant-flow/emergency-systems/165-ntg-co-pilot-portable-o2-copilot Thankfully, never needed it and I've had my share of O2 interruptions that I quickly discovered and corrected before ever getting that hypoxic. But I won't fly the FL's without it on board. 

Personally, I've been too paranoid to fly in the Flight Level solo for this reason. My Flight Level flights are with my pilot wife aboard. Despite how confident I am in recognizing my hypoxic symptoms it only takes a kink'd hose as Paul suggested and add in being distracted from perhaps a high workload and it not too hard to imagine missing a problem before you run out of time to correct it.

Edited October 23, 2017 by kortopates

[exM20K]

I carry one of these with a refill bottle *and check it before every O2 flight*

I have an old, original Nonin Pulse Oximeter that eats batteries like they're free, and that is my standby (with batteries uninstalled).  My primary is one of these:

http://lgtmedical.com/kenek/O2.html

 

It plugs into the iPad, so I can basically leave it on all the time.  If only I could get the split-screen to work, I'd have foreflight and O2 simultaneously.  Levels check against the Nonin perfectly.

 

Thinking seriously about a MH O2D2, which will alarm if you quit breathing.  I just haven't figured out how to mount it into the ceiling O2 ports of the M20TN factory system without creating a forest of tubes.  Any tips on where to mount these devices so the alarms are useful but they are not in the way?

-de

Edited October 23, 2017 by exM20K

[kortopates]

21 minutes ago, exM20K said:

.....

Thinking seriously about a MH O2D2, which will alarm if you quit breathing.  I just haven't figured out how to mount it into the ceiling O2 ports of the M20TN factory system without creating a forest of tubes.  Any tips on where to mount these devices so the alarms are useful but they are not in the way?

-de

I personally have no desire to complicate my very simple Mooney O2 system with a battery dependent O2 delivery system. Although the battery's are suppose to last a long time, we read here on MS about a pilot that had a sudden loss of O2 when the battery's died on this system. There is no fail safe delivery without power - it cuts off O2 entirely. No thank you.

In my view, our altitude compensating regulators already reduce the flow by altitude, plus using a good calibrated flow meter like the Precise A5 coupled with oxysavers cannuals (or the mask when required) allows us to fine tune our O2 flow to maximize time and maintain O2 blood levels to whatever we want - all the while without introducing further risk of adding failure points. With a good flow meter and our 115 cuft tank, my wife and I have no problem completing most multi-leg trips without needing an O2 refilll except for the very longest trips. At home I have my own 2 tank refill system, and only the longer international trips have required a refill away from home, my O2 is very affordable. Although the pulse demand is a great concept, I see little benefit and lots of added risk making our otherwise very simple and reliable O2 system battery dependent. just my 2 cents with lots of Mooney x-ctry time at altitude.

[gsxrpilot]

Physiology certainly plays into the equation here. And while youth and health do play some role, it's been well documented in the high altitude climbing community that some people tolerate low O2 much better than others. I've only had a passenger with me a couple of times up in the flight levels, but that experience has taught me that I'm on the lucky side of the equation and have a pretty good tolerance and much better than the passengers who have flown with me. If I was as quickly incapacitated as others I've seen at altitude, I'd probably never go high unpressurized no matter what precautions were in place.  As it is, I'm hyper-aware of what's going on when I'm up high. This involves using the pulse ox, monitoring the level of O2 in the tank and verifying it's rate of decline, holding an emergency can of air in my lap, and having the altitude pre-select armed and set for lower.

So far, the experience of traveling at FL250 or FL260 in my 252, has been a very positive experience. I'm hoping it stays that way.

[gsxrpilot]

3 minutes ago, kortopates said:

I personally have no desire to complicate my very simple Mooney O2 system with a battery dependent O2 delivery system. Although the battery's are suppose to last a long time, we read here on MS about a pilot that had a sudden loss of O2 when the battery's died on this system. There is no fail safe delivery without power - it cuts off O2 entirely. No thank you.

In my view, our altitude compensating regulators already reduce the flow by altitude, plus using a good calibrated flow meter like the Precise A5 coupled with oxysavers cannuals (or the mask when required) allows us to fine tune our O2 flow to maximize time and maintain O2 blood levels to whatever we want - all the while without introducing further risk of adding failure points. With a good flow meter and our 115 cuft tank, my wife and I have no problem completing most multi-leg trips without needing an O2 refilll except for the very longest trips. At home I have my own 2 tank refill system, and only the longer international trips have required a refill away from home, my O2 is very affordable. Although the pulse demand is a great concept, I see little benefit and lots of added risk making our otherwise very simple and reliable O2 system battery dependent. just my 2 cents with lots of Mooney x-ctry time at altitude.

Very interesting points... Maybe I can keep that AMU in my pocket for now.

Thanks,

[anthonydesmet]

All these are good suggestions especially an alarm if you are not getting flow to the mask.  However I am hear to tell you having personally experienced hypoxia every four years during my aviation physiology refresher in the Navy and also experiencing it once in an F-14, all the alarms, bells and whistles wont help if you’re already hypoxic. The key is to know your own hypoxia symptoms which we experienced every time in a pressur chamber.  Mine are sweats, burning in my finger extensions and irritability. The second time I experienced hypoxia in the Hornet I felt the symptoms, we got down to below 24K (pressurized cabin with a cabin altitude below 10K) and canceled the mission.  Turns out it was my OBOGS regulator wasn’t working properly which the PR’s found post flight.

If you are a “fly above 10k” guy and you have the chance to execute a pressure chamber ride I highly recommend it because you won’t forget what it feels like.  Plus the eye opener of having little to know cognitive ability.  In the chamber my task was to stack alternating shaped blocks.  Passing through 19k without O2 on our way up to 25K I couldn’t remember what I was supposed to do and just sat there with blocks in my hand.  I was awake but not functioning.  If you think you’re going to have the ability to remember to descend let alone the motor skills to do it, you won’t.

  If you can’t get a chamber experience, it’s always good to review yourself during your pre flight brief the hypoxia symptoms.  I think you can find them in the Basic MED lecture series and splattered all through AOPA online.  If your climbing through +/- 15K and your sweating with air vent open and an outside temp of 0 deg Celsius and don’t feel right or maybe it’s taking you longer time than usual to dial a frequency in, it might be time to check your flow.

 

[rbridges]

5 hours ago, gsxrpilot said:

One thing I do whether solo or with a copilot, is to have the altitude preselect armed for a lower altitude with a pretty high rate of decent. With that configured, it only takes one button push to send us down to thicker air and level off there.

 

I'm ashamed to ask this question since I work in the medical field, but how much oxygen is available at 25k feet?  I guess you pass out and revive at lower altitudes?  How long can you be "passed out" at that altitude with no ill effects?

[Marauder]

3 minutes ago, rbridges said:

 

I'm ashamed to ask this question since I work in the medical field, but how much oxygen is available at 25k feet?  I guess you pass out and revive at lower altitudes?  How long can you be "passed out" at that altitude with no ill effects?

It isn't just the lack of oxygen but also the atmospheric pressure needed to force uptake of the available O2. That is what drives the need to move from a cannula to a mask at the higher altitudes. If you "pass out" at the higher altitudes, it's a permanent pass out. 

[Bravoman]

It’s amazing  how the time of useful consciousness drops off after 20,000 feet.  I have flown higher than that in my bravo, but really don’t like to for that reason. 

[exM20K]

24 minutes ago, gsxrpilot said:

Very interesting points... Maybe I can keep that AMU in my pocket for now.

Thanks,

ditto.  the lack of a fail-safe full open is kinda scary.

I do like the idea of demand flow as the constant flow is what is irritating to my PAX on long trips - blowing on and drying out the nasal passages.  Coupled with a canula/boom system, this should be very comfortable, but w/o a fail-safe: no thanks.

-de