Mooney Down (03/25/24) - Near St. Augustine-Northeast Florida Regional Airport, FL (UST)

[PeteMc]

Just heard that N4387W (252) when down today in the woods by KUST.  Sadly two fatalities, but no other details in the story I read.

Condolences to the family(s) if anyone knows them....

 

[wiguy]

 Some mention of a door coming open during takeoff!?
 

 https://archive.liveatc.net/ksgj/KSGJ1-Twr-Mar-25-2024-1530Z.mp3
 

https://globe.adsbexchange.com/?icao=a54438&lat=29.963&lon=-81.358&zoom=13.2&showTrace=2024-03-25&timestamp=1711381992

  The audio starts just before 20 minutes.

Edited March 25, 2024 by wiguy

[Shadrach]

1 hour ago, wiguy said:

 Some mention of a door coming open during takeoff!?
 

 https://archive.liveatc.net/ksgj/KSGJ1-Twr-Mar-25-2024-1530Z.mp3
 

https://globe.adsbexchange.com/?icao=a54438&lat=29.963&lon=-81.358&zoom=13.2&showTrace=2024-03-25&timestamp=1711381992

  The audio starts just before 20 minutes.

It’s clear that he had a door pop after departure but that in and of itself did not seem to cause the accident. Tower controller was the portrait of accommodating and  professional. I imagine there will be security camera footage of the final moments. Grateful that no one on her ground was injured. RIP. 

[LANCECASPER]

https://aviation-safety.net/wikibase/371054
 
Wow we've lost two 252s in the past week. They only made two hundred thirty one of them to begin with. 
 
https://www.wokv.com/news/local/st-johns-county/st-johns-deputies-responding-reported-plane-crash-north-northeast-florida-regional-airport/RATGNFEU2ZAEHIUQ6R2HQK4U4U/


They didn’t get very far after take-off

 

This looks like the airplane from the last time it was for sale:

https://www.aircraft.com/aircraft/223027779/n4387w-1987-mooney-m20k-252tse

(Beautiful airplane, but the OCD in me asks why would you let the paint shop use an upside-down "M" stencil instead of a "W"?)

 

Looks like the airplane belonged to Ronald Hofer of Mooresville NC (14A), Lake Norman Airpark. He appears to have owned it since August of 1998.

[201er]

Sounds similar to the one in Canada not too long ago but with a much worse outcome

 

KSGJ 251556Z 07010KT 10SM OVC041 21/16 A3013

10 knot tailwind on base leg would imply about a 74 knot indicated diminishing to 63 in the base to final turn.

Popped door not only requires maintaining focus but also carrying additional airspeed. Something about how the air flows or the airspeed indicator indicates appears to require about an additional 10 knots of airspeed to maintain the same angle of attack in my experience. I NEVER let anyone else close my door and it hasn't happened in a decade since.

[Shadrach]

3 minutes ago, 201er said:

Sounds similar to the one in Canada not too long ago but with a much worse outcome

 

KSGJ 251556Z 07010KT 10SM OVC041 21/16 A3013

10 knot tailwind on base leg would imply about a 74 knot indicated diminishing to 63 in the base to final turn.

Popped door not only requires maintaining focus but also carrying additional airspeed. Something about how the air flows or the airspeed indicator indicates appears to require about an additional 10 knots of airspeed to maintain the same angle of attack in my experience. I NEVER let anyone else close my door and it hasn't happened in a decade since.

perhaps there is a pressure drop in the cabin affecting IAS? like when opening the pilot side window in flight.  Cant imagine it would affect the airfoil much nor the ram air at the pitot.

PSA.  A door pop does not require a RTB. Door can be closed in level flight with little trouble.

[wiguy]

 I don’t own a Mooney, sorry. With the plane I do own I have 2 main entry doors and a cargo door. They all hinge against the airflow, as most do. Back when I had my Cherokee I unlatched a door just after takeoff while the son was flying. With most any plane I’ve known, an unsecured door is almost a non-event. It’s a distraction for the most part, yes, there are exceptions. .

 There is no reason to RUSH for a landing. With the ads feed he looked a little tight turning final, with a casual look. 

[Schllc]

1 hour ago, Shadrach said:

perhaps there is a pressure drop in the cabin affecting IAS? like when opening the pilot side window in flight.  Cant imagine it would affect the airfoil much nor the ram air at the pitot.

PSA.  A door pop does not require a RTB. Door can be closed in level flight with little trouble.

I have read that you can close it in a side slip, and I had the door pop open two times in the first year I owned my first Mooney, I don’t know about any other models, but I could not close the door of my ovation in the air.   The main latch would catch but the pin at the top of the door would not even come close. 
why would the open door affect the ias?

[DXB]

1 hour ago, 201er said:

 

Popped door not only requires maintaining focus but also carrying additional airspeed. Something about how the air flows or the airspeed indicator indicates appears to require about an additional 10 knots of airspeed to maintain the same angle of attack in my experience. I NEVER let anyone else close my door and it hasn't happened in a decade since.

 

This makes little sense to me right now, but if your statement is true, it's certainly worth resolving my ignorance on this topic. Could the popped door could create an artifactual reading at the static port behind? I have no clue. All I would expect is a slight increase in parasitic drag. I can't imagine how it would change AOA directly.   FWIW my door has popped many times (long painful door mechanics story), but I've never noted the slightest difference in aircraft handling.  A 10kt increase in when it stalls is dramatic when landing and would have led to a surprise when lifting the nose once over the runway to land.

[exM20K]

It could also be the baggage door

[LANCECASPER]

I haven't listened to the ATC recording, but what I don't understand, looking at his track, is why he didn't declare an emergency and land back on 13. He was on a left downwind for it after take turning crosswind.

[Shadrach]

21 minutes ago, Schllc said:

I have read that you can close it in a side slip, and I had the door pop open two times in the first year I owned my first Mooney, I don’t know about any other models, but I could not close the door of my ovation in the air.   The main latch would catch but the pin at the top of the door would not even come close. 
why would the open door affect the ias?

I’ve never had a door pop but I once departed with some seatbelt webbing closed in the door. I had moved the pax seat forward for some reason and the part of the door with the belt tail hanging out was on scurry from view. At some point in the climb,  I heard a slapping noise.  Took a few seconds to realized what I had done. At about 3k I slowed to 100mias. I then opened the pilot side window (don’t think it mattered one bit given the size of the cabin vents but remember reading about it so I did it). I then unlatched the door, retrieved the seat belt tail and closed the door. It was not difficult at all.  I have very good mating between door jam and door (absolutely no leaks) so maybe that helped.

As to ASI increase with door opening, you raise an interesting question that leads me to believe that my alternate static source is open. If I open the pilot side window in flight, my indicated altitude jumps about 80ft and my IAS jumps a few knots.

[flyboy0681]

Having experienced an open door three times, once with Gary "Fantom" Hellman (may he rest in peace) on board. He was a strong guy and even he couldn't close it, so we flew on with it open. Other than a lot of noise, it doesn't cause much fuss in terms of handling difficulties. But as exM20K stated, it could have been the luggage door.

[PeteMc]

3 hours ago, DXB said:

Could the popped door could create an artifactual reading at the static port behind?

Isn't that kind of the point of having one on each side?  And in all the discussions in various plane checkouts, I've never had a CFI tell me to watch out for the Airspeed being off if the door pops open. 

ADDED:  There is a big issue if you are using the Alternate Static Source.  You should never open the window and although not mentioned, I guess that warning would include the door too.

 

Edited March 26, 2024 by PeteMc

[Ragsf15e]

Are the ADSB altitudes usually pretty accurate?  I wonder what else was going on, but typically you’d want to get higher than 700’.  He was abeam the numbers at like 400-500’.  That can make your pattern look wide enough when it’s not.  Couple that with low airspeed, distraction, and find yourself in a tight turn to final.  Probably heavy too since he just took off.  
 

I had a pilot induced door failure once as well.  Didn’t get the top latched before takeoff.  I was at mgw and high DA.  Decided to slow to 100, open and fully close… it was impossible to open the door more than 1” or close it fully.  I didn’t try slower or slipping based on my situation.  Considered landing but didn’t like the weight, DA, etc.  climbed up to 10,000 and flew 3 hours to my destination (yes it was annoying, luckily no pax).  It was a non event to land, but the door did pop open on landing.

Could have been his baggage door… that would be even more distracting based on other people’s descriptions.

[Shadrach]

40 minutes ago, Ragsf15e said:

Are the ADSB altitudes usually pretty accurate?  I wonder what else was going on, but typically you’d want to get higher than 700’.  He was abeam the numbers at like 400-500’.  That can make your pattern look wide enough when it’s not.  Couple that with low airspeed, distraction, and find yourself in a tight turn to final.  Probably heavy too since he just took off.  
 

I had a pilot induced door failure once as well.  Didn’t get the top latched before takeoff.  I was at mgw and high DA.  Decided to slow to 100, open and fully close… it was impossible to open the door more than 1” or close it fully.  I didn’t try slower or slipping based on my situation.  Considered landing but didn’t like the weight, DA, etc.  climbed up to 10,000 and flew 3 hours to my destination (yes it was annoying, luckily no pax).  It was a non event to land, but the door did pop open on landing.

Could have been his baggage door… that would be even more distracting based on other people’s descriptions.

It’s pressure altitude so it can be off by hundreds of feet. As much as 300’-500’ off is not uncommon. The inaccuracies are usually consistent throughout a pretty large range of altitudes, e.g. if I level off at 4500 and then climb and level off at 8500 the ADS-b data might show 4760’ and 8775’. 

[toto]

It's obviously hard to tell from a recording, but the pilot sounded pretty relaxed on the radio.  He didn't seem to be task saturated.

Feels like this is going to be a base-to-final stall/spin, maybe aggravated by the odd IAS behavior described above.

As mentioned, he flew a strangely low pattern, with a strangely long downwind.  It's possible that he made the  radio call and then became preoccupied trying to get the door closed, followed by a late base turn and a tight base-to-final.  The stall horn would be blaring even if the IAS was off, but if he was saturated he might have been thinking "gear" - and lowering the gear would only aggravate the situation in a tight turn at minimum airspeed.

[Ragsf15e]

15 minutes ago, Shadrach said:

It’s pressure altitude so it can be off by hundreds of feet. 300-500’ off actual is not uncommon. The inaccuracies are usually consistent throughout a pretty large range of altitudes, e.g. if I level off at 4500 and then climb and level off at 8500 the ADS-b data might show 4760’ and 8775’. 

So maybe he got to a good, normal pattern altitude after all.

[Shadrach]

54 minutes ago, flyboy0681 said:

Having experienced an open door three times, once with Gary "Fantom" Hellman (may he rest in peace) on board. He was a strong guy and even he couldn't close it, so we flew on with it open. Other than a lot of noise, it doesn't cause much fuss in terms of handling difficulties. But as exM20K stated, it could have been the luggage door.

I did not know that “Fantom” had passed. I always wondered what became of him. I enjoyed his aviation insights and his dry sense of humor. How long has he been gone? 

Seems everyone has had trouble with a door close in flight. I guess I’ll have to make a video demo. Did you and Gary slow down? I’ve never tried it at cruise speed. 

[Shadrach]

Just now, Ragsf15e said:

So maybe he got to a good, normal pattern altitude after all.

Perhaps. Looking at ADSB data from other AC in the area at the time of the accident would give a better idea.

[Ragsf15e]

1 minute ago, Shadrach said:

I did not know that “Fantom” had passed. I always wondered what became of him. I enjoyed his aviation insights and his dry sense of humor. How long has he been gone? 

Seems everyone has had trouble with a door close in flight. I guess I’ll have to make a video demo. Did you and Gary slow down? I’ve never tried it at cruise speed. 

It seems like it’s solid metal 1” open with no hinge at cruise speed.  I had 3 hours to play with it.  You can neither open it or close it, although I only had my interior pull strap to pull on, so I don’t think I pulled so hard that id separate that from the door panel.

[Shadrach]

4 minutes ago, Ragsf15e said:

It seems like it’s solid metal 1” open with no hinge at cruise speed.  I had 3 hours to play with it.  You can neither open it or close it, although I only had my interior pull strap to pull on, so I don’t think I pulled so hard that id separate that from the door panel.

I honestly had no problem opening and closing the door to retrieve the seat belt tail. I don’t remember exactly how I set the airplane up. Maybe trimmed for nose up… this was at least 6 years ago so not fresh in my mind. Just remember that I was expecting it to be a problem and was pleasantly surprised.

[201er]

32 minutes ago, Ragsf15e said:

So maybe he got to a good, normal pattern altitude after all.

Altimeter 30.13. So pressure altitude is about 200ft lower. When ADSB shows 600, should be 800MSL. Still kinda low.

[skydvrboy]

My Mooney specific transition instructor ripped my factory original door handle off trying to close the door in flight after he didn't get it closed properly.  We tried slowing and slipping but nothing seemed to work, so he tried a "little" harder.  Then I got the pleasure of custom making a new handle that is much nicer. 

[skydvrboy]

If your airspeed or altitude change when opening the door (or pilot window), it's likely that your alternate static port is open.  This happened to me during PPL training in a Warrior.  After back on the ground, we flipped the valve the other way which caused the altitude and airspeed to remain constant when opening the door.