Dead stick instrument approach

[Will.iam]

8 hours ago, hubcap said:

Does anyone really think they could successfully shoot an ILS or LPV approach in IMC without power? I am just curious, because I don’t think I could. 

Well you get one shot at it if the engine ever quits on you in the soup. And the body can’t go where the mind hasn’t already been.   Main reason we practice emergency procedures to have your mind exercised to already been there done that so when it happens for real you already have a game plan for what to do so as to not waste time trying to figure it out if you never thought about what you would do.
 

If you believe you can’t you can’t, if you believe you can you can. Either way you’re right. 

[hubcap]

3 hours ago, Will.iam said:

Well you get one shot at it if the engine ever quits on you in the soup. And the body can’t go where the mind hasn’t already been.   Main reason we practice emergency procedures to have your mind exercised to already been there done that so when it happens for real you already have a game plan for what to do so as to not waste time trying to figure it out if you never thought about what you would do.
 

If you believe you can’t you can’t, if you believe you can you can. Either way you’re right. 

I believe it is a bad game plan to try to do something like fly an ILS with a dead stick. Just because you believe you can doesn't mean you can. The graveyards are full of dead pilots who thought they could do something that they could not do. 

I believe @Andy95W had the right idea. Fly the plane as far into the crash as possible and hope that the ceiling is high enough to maneuver a bit when you can see the ground...

[GeeBee]

To make the field dead stick you need about a 6 degree slope. Messing around with this in my and other simulators reveals if you take the AGL altitude at the marker and double it. Then add 1000'. This is because when you drop the gear, your glide ratio goes down quickly. Even then, don't drop the gear until 200'. I've managed to make it work in everything from an A330 to a C-182RG.  Recognize however if you drop through the glide slope prior to the MAP, you're likely toast. You want to arrive at the MAP just as the GS is starting to center. You'll hit brick one, not the TDZ but you'll make it. Barring that, best to do an overhead circle but in reality, 500' ceiling is about the minimum for that. Single engine IMC is a calculated risk and light twin IMC until you are above Vyse is an even bigger risk.

[Shadrach]

21 minutes ago, GeeBee said:

To make the field dead stick you need about a 6 degree slope. Messing around with this in my and other simulators reveals if you take the AGL altitude at the marker and double it. Then add 1000'. This is because when you drop the gear, your glide ratio goes down quickly. Even then, don't drop the gear until 200'. I've managed to make it work in everything from an A330 to a C-182RG.  Recognize however if you drop through the glide slope prior to the MAP, you're likely toast. You want to arrive at the MAP just as the GS is starting to center. You'll hit brick one, not the TDZ but you'll make it. Barring that, best to do an overhead circle but in reality, 500' ceiling is about the minimum for that. Single engine IMC is a calculated risk and light twin IMC until you are above Vyse is an even bigger risk.

Don’t marker beacons vary in distance from the threshold if even installed and in service?

Edit: Your formula works at the IAF for my home drome. I’d need to start the approach at 9,000.

[Will.iam]

41 minutes ago, hubcap said:

I believe it is a bad game plan to try to do something like fly an ILS with a dead stick. Just because you believe you can doesn't mean you can. The graveyards are full of dead pilots who thought they could do something that they could not do. 

I believe @Andy95W had the right idea. Fly the plane as far into the crash as possible and hope that the ceiling is high enough to maneuver a bit when you can see the ground...

Well trying to fly the ILS isn’t going to work as already stated we don’t  have a 19:1 glide ratio. You would be lining up laterally with the loc and hopefully you were lucky enough to be within glide range when the engine quit. If no airports within glide range then you get to do like Andy95w commented about. But for me if I’m within glide range Of an airport I’m going there as i know there is smooth surface to land on and maybe even emergency equipment. If I don’t have excess altitude then I’m taking what ever angle i am to the runway. If I’m high enough to turn toward the runway bonus. 

[201Steve]

1 hour ago, Shadrach said:

Edit: Your formula works at the IAF for my home drome. I’d need to start the approach at 9,000.

That doesn’t give you much space, if any, to manuever into position from where you are. If you are NA and cruising at 7-10k….

[GeeBee]

1 hour ago, Shadrach said:

Don’t marker beacons vary in distance from the threshold if even installed and in service?

Edit: Your formula works at the IAF for my home drome. I’d need to start the approach at 9,000.

The distance varies, but a 3 degree slope is a 3 degree slope. The crossing altitude reflects the distance based upon the slope. The IAF and intermediate segments are not part of the slope by the way.

[Shadrach]

37 minutes ago, 201Steve said:

That doesn’t give you much space, if any, to manuever into position from where you are. If you are NA and cruising at 7-10k….

Agreed.  I would never try it unless it was the best (as in only) option. Better to navigate to an intersection closer to the threshold and arrive there >2X glideslope altitude above TDZE.

 

31 minutes ago, GeeBee said:

The distance varies, but a 3 degree slope is a 3 degree slope. The crossing altitude reflects the distance based upon the slope. The IAF and intermediate segments are not part of the slope by the way.

Makes sense.  So arriving at Nolin at 5400 (2900-TDZE+1000) would give you ~8.8NM of glide distance to make a threshold that is 6.6NM away provided you could maintain a 10:1 ratio. Rounding the the direction of being conservative, even if you get there at 2X the intersection AGL altitude of 4400 you still have a reasonable chance of making it (7.2NM of glide distance to cover 6.5NM).  

 

[David Lloyd]

Steve201, this one of the very best questions I have seen asked on Mooneyspace.  A bunch of people are calculating, how could this be done successfully? In years past, the best solution would have been to turn toward a nearby airport, maybe ask for vectors, circle the airport if near enough and pray to break out with enough altitude to maneuver to a safe landing. 

Today, our GPS navigators will not only give us our pick of nearest airports but show an approach and have it loaded in seconds. Garmin’s Smartglide will even show if we are within glide range. Now the question becomes, what AGL altitude and speed do I need crossing the FAF in order to put the wheels on asphalt?  Don’t have that answer today but will by next week.

Several years ago I was just given a descent from 11,000, headed for a GPS to minimums approach to Linden, NJ. A couple seconds later, I informed center of an alternator failure and requested an immediate turn and vectors ILS 6 at Allentown. I had just listened to their ATIS minutes before and would much rather go for a sure thing at ABE than some iffy result at LDJ. If the radios went dark, Newark airspace with low clouds would be a bad place to be. VFR weather was 150 miles west.  Point is, always know where you are, what is near by, the weather, your options. Don’t wait until the grits have hit the fan.

[Hank]

2 hours ago, David Lloyd said:

Point is, always know where you are, what is near by, the weather, your options. Don’t wait until the grits have hit the fan.

Excellent advice!! It will help you if you have a problem, and will prevent t the sad waste of breakfast food . . . .  

[201Steve]

2 hours ago, David Lloyd said:

Point is, always know where you are, what is near by, the weather, your options. Don’t wait until the grits have hit the fan

@David Lloyd yay, best question award. Que the ceremony music! 
 

anyway, agree with this 100%. It’s one thing to say, know what’s around you, etc. it’s another thing to assess what is relevant and how to realize that advice in practice. Example, someone told me one time ( @FlyWalt )that when they fly at night, they click airport lights on as they go by. I don’t think I would have thought of that on my own. I started this practice. Coming home in a twilight, I was 40 miles from home and had just illuminated the lights over a passing field when I noticed my oil pressure flickering. No thinking or twisting necessary, I just landed at that airport. The defeating part of the story is that, it turned out not to be my oil pressure gauge. It was my factory CHT gauge bouncing around, that I generally never look at anyway since I have digital engine monitor. But it’s right next to my oil pressure and it was low light. Anyway, it was a good experience nonetheless bc it reinforced this concept of staying ahead of your decisions, with already loaded knowledge, that made the “emergency” a non event. 
 

This kind of discussion is the same a-ha information I’m looking for to be best prepared for such an event as brought up here. 
 

And frankly, making risk assessments independent of departure and arrival  conditions, to determine if I feel comfortable flying over vast swaths of low ceilings. 

[carusoam]

Another tool to add to the box…

Knowing your actual glide ratio numbers…

MSer @cnoe has written about testing his M20J’s glide ratio in a nice thread around here…

Lots of small details that add up over the minutes travelled…

Great question!

Fantastic MSer answers… including broad experience from simulators….

Not only do we know what doesn’t work… but what it takes to make it work…

 

Go MS!

Keep the breakfast foods away from the rotating machinery….  

Best regards,

-a-

[Shadrach]

On 9/13/2022 at 10:28 PM, Andy95W said:

⬆️⬆️⬆️ This.

Attempting an actual instrument approach, in actual IMC, with a dead engine?  Nuts.

About the only thing that’s going to help is following Bob Hoover’s advice: fly the airplane as far into the crash as you can.  Hopefully your instruments and GPS will let you crash inside an airport boundary where you’ll be less likely to kill innocent people on the ground and more likely to receive prompt medical attention.

Sorry for the bluntness, but luck is going to mean a lot more than IFR skill if this actually happens.  (Luck and 1000’ ceilings.  200’ ceiling and you don’t have a chance.  1000’ ceiling and you stand a chance at finding a survivable crash site.)

Luck has everything to do with the cards you were dealt regarding where the failure occured. Managing the cards you've been dealt is almost always about skill.  Trying to fly an approach as published while engine out has known outcome. Understanding and practicing potential methods to avoid that outcome by utilizing a steeper but sustainable descent profile is not luck, it's a mitigation tactic and it's about the best we can do.

[ReconMax]

Maybe Turn Time Twist Throttle Pray? It's a very scary thought but, depending on many variables, altitude of emergency, proximity to airport, etc., a "modified" approach seems like it could work to get you below the clouds hopefully close enough to make the runway. I'm hoping we don't have 200' OVC if that ever happens to me.