Off-field emergency landing - gear up? gear down?

[AJ88V]

(Forgive me for posting something that may have been discussed on this forum dozens of times before.  If so, please point me to a thread or two. Thanks. )

The recent safe off-field landing of an M20A  (https://mooneyspace.com/topic/49305-m20a-down-in-a-corn-field/)  reminded me of a discussion we had on the old Mooney List, but I forget the consensus. 

First off, if the field or area is firm, gear down is probably preferred, but it's less clear if the the ground is soft.  

One argument was that the Mooney has a nice flat bottom that would slide if the gear was left up, and maybe this was more controllable in soft earth (e.g, a farmed field) and lead to a less-abrupt stop.  Arguing against this was that you're basically landing on your fuel tanks and risk producing a leak.  Also, the aircraft could spin (not so controllable) leading to other injuries.

The countering argument was that leaving the gear down potentially dissipated more energy, even if it tore the gear off, that uses energy to decelerate the plane, which improves survivability.  Arguing against that is all that force would likely tear open a fuel tank.

And before opening this discussion for comment, in the M20A off-field case referenced above, should you land with the furrows or against them (aligning as best as possible for wind)?  In the facebook pic, the plane looks like he landed (successfully!!!) at a 45 to the rows (maybe just aligning for wind, but there's a case for the "45 entry" as a compromise.

Your thoughts? [over]

[AH-1 Cobra Pilot]

The time I landed in a corn field was in a T-210.  I tried to land into the wind, but the center pivot was across that direction.  As it ended up, I landed with the furrows, which were nothing to worry about, anyway.  The ground was probably fairly frozen and definitely quite dry, so it was close to concrete/asphalt.  The gear were already down; no damage to the airplane, at all.

I was most happy to find out the farmer decided to put his cattle into the field the next day, or it might have had different results.  I also practically crapped my pants after I saw the power lines I flew over getting there.

[hubcap]

I have always been of the opinion that "gear up" would be preferable for an off field landing. However, one of our local Mooney pilots had his engine seize up and he landed in a cow pasture with the gear down and didn't damage the plane in any way during the landing. At the end of the day, it's probably very situational. A plowed field, no way I am going in with gear down.....a cow pasture....maybe gear down.

My main concern with gear down is not damaging the plane, I am more concerned about it flipping the plane over when the gear catch on the ground. I think it would be much easier to survive without flipping the plane over.

[Hank]

1 hour ago, hubcap said:

I have always been of the opinion that "gear up" would be preferable for an off field landing. However, one of our local Mooney pilots had his engine seize up and he landed in a cow pasture with the gear down and didn't damage the plane in any way during the landing. At the end of the day, it's probably very situational. A plowed field, no way I am going in with gear down.....a cow pasture....maybe gear down.

My main concern with gear down is not damaging the plane, I am more concerned about it flipping the plane over when the gear catch on the ground. I think it would be much easier to survive without flipping the plane over.

As you've already pointed out, it depends on what you are going to land on.

• Pasture, grassy fields, beach, lakeshore, dirt road--gear down.
• freshly-ploughed field, tall beans, fields with ditches / fences--gear up
• trees, water [lake or ocean]--gear up
• frozen ground with little growth--gear down

But regardless of thoughts in advance, you'll still need to evaluate the situation if it happens and make a choice . . . .

[ttflyer]

Also, don't overshoot your field.  We are used to the drag the gear gives us.  If we leave it up, much less drag...  Just something to think about.  I'd rather "dig in" a bit in field then sail into whatever is at the opposite end of the field...

[Vance Harral]

Other things have so much more influence on survivability in a forced landing, that the position of the gear at the moment of touchdown is not worth worrying about.  If you have time to devote to thinking about off-airport landings, you should be spending the mental energy (and training) on those other concerns - most notably glide performance, precision landings, and touching down at the slowest possible speed.

The only semi-scientific look at gear position in forced landings I'm aware of, studied ditching in the "soft surface" of water.  But the data there showed no evidence that landing gear position mattered: http://www.equipped.org/ditchingmyths.htm

8 hours ago, AJ88V said:

One argument was that the Mooney has a nice flat bottom that would slide if the gear was left up

I have no idea where this persistent myth comes from, it strikes me as lazy thinking.

First, no real-life airplane has a "nice flat bottom".  The average M20C has a chunky "chin" which holds the air filter, bulbous nose gear doors, various antennas, flap hinges, sometimes-non-retractable steps, imperfectly rigged gear doors, tie-down rings that were not removed for flight, and other protrusions that stick out and can catch things.  Yes, all those things tend to slide if you set down on pavement, but soft ground is a different story.

More importantly, Mooneys have relatively low-dihedral wings.  Catching a wingtip instead of "sliding on the belly" is a high-G deceleration event that places occupants at significant risk; and it will occur with only a slightly-less-than-perfect roll attitude on touchdown, and/or with just the smallest amount of surface variation (row furrows, rocks, dirt clods, vegetation, etc).  The likelihood of digging in a wingtip is even higher given that your "not perfectly smooth bottom" is likely to impart a certain amount of rolling motion on impact.  No, I don't have NTSB data on this, but I do have a lifetime of bellying in model airplanes with no landing gear (and much smoother bottoms) on grass, and it often doesn't go the way you hope - in particular, I've seen plenty of flip-overs.  So whatever you're afraid of "catching" the landing gear on may be an actual threat, but you're at least as likely to catch a wingtip on that same threat as you are the gear; and if you do, you'll get a sideways slewing motion that most aircraft seat belts are not designed to guard against.  This goes for mild sea swells as well as plowed field furrows, hence the data on ditching that gear position doesn't matter.

My opinion - which is worth what you're paying for it - spend less time thinking about gear position and the direction of furrows; more time on making the field in the first place, and arriving there with wings level and minimum energy.  My experience with power-off 180s (both teaching them, and my own ineptitude) suggest to me that most of us are terrible at this.  Accordingly, the only value in worrying about aircraft configuration is with respect to arriving at the intended touchdown point with minimum energy.  Anything else is like worrying about whether you should roll the windows up or down on your car, as you're driving over a cliff.

[MB65E]

Have any moonies flipped due to the gear down off field like Cessnas do? 
The lower CG might suggest to land gear down all the time off field. 
I’f everything goes ok, you’d still have a salvageable airplane. 
-Matt

[1980Mooney]

1 hour ago, MB65E said:

Have any moonies flipped due to the gear down off field like Cessnas do? 
The lower CG might suggest to land gear down all the time off field. 
I’f everything goes ok, you’d still have a salvageable airplane. 
-Matt

Not often.  But it has happened.  Usually other obstructions in the landing path.  Roll the dice.

"The pilot decided to not continue the flight to the nearest airport; he shut down the engine and perform a forced landing to a field. During the forced landing, the airplane impacted unsuitable terrain and sustained substantial damage to the forward fuselage. "

https://asn.flightsafety.org/wikibase/383084

 

[AJ88V]

29 minutes ago, 1980Mooney said:

Not often.  But it has happened.  Usually other obstructions in the landing path.  Roll the dice.

"The pilot decided to not continue the flight to the nearest airport; he shut down the engine and perform a forced landing to a field. During the forced landing, the airplane impacted unsuitable terrain and sustained substantial damage to the forward fuselage. "

https://asn.flightsafety.org/wikibase/383084

 

That picture is horrifying!  But it seems the pilot walked away.  Amen!

[A64Pilot]

I think it’s going to depend on what it takes to make the landing area, if you have to stretch the glide, gear up, coming in a bit long, gear down.

A couple of things when a pilot has to ability to determine the landing area as in plenty of altitude, most overshoot.

Secondarily believe it or not but I think almost all would say water landing, gear up, but I read an article the other day that said it makes no difference in survivability one way or the other.

Finally I think gear down there is at least some possibility the aircraft won’t be badly damaged, while gear up it’s exceedingly unlikely, so for me if I have plenty of altitude and can pick, I think I’m going in gear down, to some extent because I believe the gear can absorb and dissipate some energy

[A64Pilot]

6 hours ago, AJ88V said:

That picture is horrifying!  But it seems the pilot walked away.  Amen!

To me it looks like a stall at significant altitude?

[Vance Harral]

11 hours ago, MB65E said:

Have any moonies flipped due to the gear down off field like Cessnas do?

Plenty of Cessnas remain upright in off-field landings, even ones rough enough to tear up the airplane.

[hazek]

On 8/29/2024 at 12:47 AM, Vance Harral said:

Anything else is like worrying about whether you should roll the windows up or down on your car, as you're driving over a cliff.

Except when the length of field available is such that you should consider how long your ground roll will be before you hit a major obstacle. Then it absolutely matters whether or not you choose gear up or down just as much as actually hitting the field. 

[Pinecone]

15 hours ago, A64Pilot said:

A couple of things when a pilot has to ability to determine the landing area as in plenty of altitude, most overshoot.

I would rather overshoot and hit things at less than 20 knots than to undershoot and hit them at 70 knots.

[A64Pilot]

28 minutes ago, Pinecone said:

I would rather overshoot and hit things at less than 20 knots than to undershoot and hit them at 70 knots.

The thing that brings down Ag planes more often than anything else is engine failure. 

It’s more common than not for them to end up in the trees at the end of the field, than to be stopped in the field, however they most often make the field.

Obviously their case is different maybe because most often they only have seconds to pick the forced landing spot, I think they misjudge how far the flare is going to carry them.

Just an observation is all.

[rickseeman]

Many have died thinking they could land gear down.

 

I don't recall anybody dying because they landed gear up.