How to ditch

dmccormack

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Dan Mc
The ditching fatality came to mind as I was flying the other day. I wondered what the best way to ditch in a lightweight tailwheel would be.

I remember reading somewhere (Kershner?) that ditching in a fixed gear will invariably end in a forward flip.

But does that refer to conventional gear as well?

What's the best procedure to ditch a tailwheel?

Discuss amongst yourselves... :D
 
The ditching fatality came to mind as I was flying the other day. I wondered what the best way to ditch in a lightweight tailwheel would be.

I remember reading somewhere (Kershner?) that ditching in a fixed gear will invariably end in a forward flip.

But does that refer to conventional gear as well?
There was a Citabria involved in a midair over Commencement Bay in Tacoma a couple of years back. While the plane didn't exactly come down "controlled" (the vertical stabilizer and rudder were gone), it came down fairly flat and *didn't* flip on impact. The pilot got his mother out of the back seat with little problem.

If a taildragger only partially under control didn't flip, there's hope for the rest of us....

Ron Wanttaja
 
I am doing this from memory, so I may miss something.

If possible choose another landing area:yesnod:.

Make the radio calls so help can be dispatched.

Brief the Passengers.

Prepare the cockpit:
secure all loose items.
don PFDs.
tighten seat belts and shoulder harness.
unlatch doors (jettison if possible).
activate ELT.

Make your approach into the wind.
(note) If there are significant swells or waves you will have to make a judgement call as to whether it is better to land parallel to them or into the wind. Waves and swells can "trip" the plane making it more prone to go onto it's back.

Just before touchdown:
shut off all fuel valves(if you have fuel why are you doing this?):skeptical:.
turn off ignition and all electrical switches.

Judging your height above the water is sometimes very difficult, especially if the water is glassy. This makes the landing attitude somewhat of a crap shoot. If you judge it right, make the landing as slow as possible with a slightly nose up attitude.

Some airplanes will float. Empy fuel tanks make this more likely unless they were breached in the landing. If the airplane goes onto its back it can be very disorienting(hence the open doors before touchdown).

Exit the airplane and if it is floating stay close for identification by searchers.
 
One caveat to staying close to the airplane. If you've got a fuel spill on the water you can get serious (skin graft serious) burns from swimming around in the fuel for prolonged periods.
 
All good info -- thanks....

I assume the landing should be what every landing should be -- minimal energy required to maintain controlled flight until touchdown, with no special / different attitudes.

On a related note -- we have lots of hills here. I've often though that landing downhill would increase speed and make the impact worse.

But uphill landing will require a fairly steep pitch attitude.

So is the best plan to dive, then zoom up and touchdown uphill?
 
Just from landing on sloping runways - I feel that I do better landing uphill (even with a tailwind component).
 
I've been told on a fixed gear airplane that you want to ditch with more of a nose up attitued then normal. The best bet to keep from flipping is to sink the wheels straight into the water so if you have forward mometum your wheels need angled out in front of you and stall it into the water.
 
I've been told on a fixed gear airplane that you want to ditch with more of a nose up attitued then normal. The best bet to keep from flipping is to sink the wheels straight into the water so if you have forward mometum your wheels need angled out in front of you and stall it into the water.

What about a tailwheel? I'd guessing -- only -- that once the tailwheel touches the water there will be a very rapid reduction in speed.
 
In case of ditching, brief passengers:
1) tighten seatbelt and shoulder harness TIGHT
2) which door to leave from
3) brace position
one hand on seatbelt near buckle so it can be found and released in dark
one hand on shoulder harness or seat above forming a pillow for head, head in pillow
feet back under seat, not crossed, not hooked on anything (pilot keeps feet on rudder-expect broken ankles)
4) do not inflate life raft INSIDE the aircraft
 
4) do not inflate life raft INSIDE the aircraft
Or too close to something sharp on the aircraft, like the trailing edge, as there have been ferry pilots that popped their raft inflating off the trailing edge.
 
Missa,

There is only so much nose up attitude until the tail touches first. When the tail hits the water it will not significantly slow the forward momentum before the mains hit.
When the tail hits it will cause the mains to immediately slam down into the water.
Will a tailwheel dig into the water more and cause the mains to come down harder?
Will no tailwheel allow the tail to "slide" on the water easier and have more time to slowly lower the mains?
Will a nose wheel dig in and cause the plane to go on it's back quicker?

My thinking is to land as slowly as possible, slightly nose high. The exact attitude, if controllable, may depend on the configuration of the gear.
 
Some airplanes will float. Empy fuel tanks make this more likely unless they were breached in the landing.
Empty tanks (full of air) might float pretty well, but so will tanks full of fuel, which has a lower density than water.
Deep-sea bathyscapes like the Trieste used a huge metal "balloon" filled with gasoline for "lift". After dropping their ballast at the bottom, the tank of gasoline would carry them right to the surface. They used gasoline instead of air because it's not as compressible as air, but you get the idea.

And unlike an empty tank, a full tank won't fill with water if the vents are submerged.

But regardless of any of that, it's probably wise to exit the aircraft ASAP... how long it will float shouldn't be a factor in making that decision.
 
Just from landing on sloping runways - I feel that I do better landing uphill (even with a tailwind component).

IMO, uphill is the only plausible choice in most cases where there's a significant slope as downhill will likely leave you rolling or sliding until you run into something solid. Just keep in mind that it will require substantial extra airspeed into the flare if the slope is steep.
 
In case of ditching, brief passengers:
4) do not inflate life raft INSIDE the aircraft

Do you mean so that this does not happen?
(Coincidentally, sent to me today by a pilot friend, it happened abt 4yrs ago)
http://safetycenter.navy.mil/media/approach/issues/sepoct06/The_Wild_Ride_of_106.htm


******
It was supposed to be a routine logistical flight.

Our six crew members included an active-duty Marine test pilot, four aircrew from Air Test and Evaluation Squadron VX-20, and a Federal flight test engineer.
Our passengers included four maintenance people and a Navy active-duty maintainer. We also carried various maintenance pack-up items and baggage.

Our mission was to reposition a Hercules KC-130T, to the expeditionary airfield at Twenty-Nine Palms for electronic-propeller-control system field testing.

We had flown this Hercules through every imaginable test configuration at NAS Pax River. All that remained was to evaluate system performance at low-level. For several days, we would fly routine missions at low altitude in the desert before returning the ' Herc ' to its parent unit.

About an hour or so after take-off, we were settled into a routine flight at 24M on autopilot. I was in the right seat and just had gotten into a comfortable position . .

. . when the Hercules suddenly pitched up hard while rolling left.

The aircraft commander (A/C) and I simultaneously lurched forward as we pushed our autopilot-disconnects. We both thought the autopilot caused an uncommanded pitch-up and wing drop.

To our further alarm, the C-130 continued its hard G pitch-up and aileron pressure . .

On its own !



Then it continued to roll more harshly to the left.
Both of us were on the controls against the roll. But it over-whelmed our combined strength. When the wings rotating beyond vertical, the Herc's nose sliced through the artificial horizon into a rolling, inverted dive.

The AIrcraft Commander : " MY controls."

I released. Although, I must admit my giving up the control yoke was not easy.

We all watched helplessly as the Hercules rolled completely over on her back, then pitched roughly, straight down.

The Herc accelerated into a rapid spinning dive to the left, as I watched my attitude indicator ' go full brown side ' while rotating like a kid's top.

Our little world suddenly became violent. Our flight engineer was pinned to the cockpit's ceiling. At the wrong time, he had unfastened his seat belt and was leaning far forward to make a fuel adjustment.

During the second diving rotation, as we experienced Negative G's and a snow storm of helmet bags, IFR approach plates, papers, coffee, dirt, dislodged knobs, were joined with a odd flight of a Subway sandwich, floating like a towed banner across my side vision.

Pandemonium reigned in the passenger/cargo area. Not one person had their seat belt on. Or even loosely in place.

Along with intense fear/terror of the unknown, all of the passengers were tossed to the ceiling and were trashed around each other within a swirling storm of loose items Herc had accumulated over its service life.

As the Hercules flew on, out of control, I saw the left seater's attitude indicator was not matching my own. In fact, it was flipping strangely and ratcheting around.

Both airspeed indicators showed 350 knots as the A/C strugged to pull up the Herc's nose. After noticing our high airspeed, I was certain that the throttles were still at cruise power. I pulled the the throttles back to flight idle.

I didn't ask.

As our airspeed began to fall off. I checked my turn and bank indicator, and I saw an uncoordinated ball max'd right, with its turn needle max'd the other direction.

I shouted, "We're spinning,"

The yell shifted the Aircraft Commander's eye balls to his turn and bank. He quickly reacted, as the Herc entered a third rotation.

The Herc's gyrations began to slow. The A/C had stopped the roll rate with rudder, but we were still pointed almost straight down.

As his attitude gyro was flipping around uselessly, he was now focusing on his rate of descent and altimeter, to perceive up from down.

As he tried to move the C-130's nose up to the horizon, I became aware of the incredible whining sound. Previously unnoticed. And over which we had both been shouting, the propellor on # 3 was reading 106% overspeed.

Still in cloud at 5,000 feet we finally got the wings level. We declared an emergency to Indianapolis Center and requested vectors to our nearest runway and also to allow us to descend out of the goop into VMC.

Still uncertain why the Herc departed controlled flight, we began to assess what caused it and check on passenger injuries. We instructed our flight test engineer to go aft. He pulled our loadmaster from under a stack of five folks that had been tossed around like tennis shoes in a clothes dryer. Fortunately, there was just a head wound, broken bones, and larcerations.

Once we descended into visual conditions, we got our first ground reference since the emergency, as we got a visual on the airport ahead.

Then someone then came over the intercom saying we were on fire. We scanned our instruments, nacelles, wings and everything visible to check for a fire. Nothing. With no time to look further, we told Indy Center the aircraft might on fire and we required an immediate landing.

Surveying the Herc's interior scenario, it looked like a bomb had gone off. Debris and passengers were strewn all over the cargo area. The flight deck was now piled with everything, including a set of wheel chocks that had migrated forward from the cargo compartment.

Turning on final approach, we had no approach plates, or checklists. Our navigator frantically grabbed through the debris to find what we needed.

Once we got our hands on the Huntington plate in West Virginia, we made a normal recovery and safe landing. Fearing fire somewhere onboard, we just taxied clear of the runway, shut down and set the brakes. Gathering our injured we evacuated.

No fire, so we climbed back in to discover what caused our life-threatening odyssey.

The was a 20-man life raft rammed into the Herc's tail feathers.

It had deployed in-flight from its wing-storage and was lodged in left horizontal stabilizer's leading edge.


A visual inspection of the aircraft by the aircrew determined both left wing life rafts had deployed in flight. And one of them had wrapped around the horizontal stabilizer, pushing the elevator full up.

We had ( 1 ) rolled over at least twice, ( 2 ) lost 9,000 feet of altitude ( 3 ) at a maximum descent rate of 29M feet per minute, ( 4 ) probably exceeded three positive and 2 negative G's [ limits = plus 3 and negative 1 ] ( 5 ) with airspeed touching 460 Knots.

The data pallet [along to record flight-test data] captured invaluable performance data and allowed us to reconstruct our flight profile. Then after extensive inspections and repairs, we later flew our aircraft home.

Reflecting on this harrowing experience, I was reminded of our good fortune in having a truly professional air crew, engaged in the important work of testing Navy-aircraft systems.

We not only survived a catastrophic malfunction, but we maintained our resilient sense of humor [ as attested to by my spotting a four-leaf clover, which I still keep in my flight suit.]

Later, a crew member found some money lying on the ground. And we all had a good laugh when one of our group said : " This must be our lucky day."

Dan Sanders is a retired Marine Corps major, employed as a contract pilot with VX-20.

Analyst comments:

No one is immune to the Blue Threat [ life-threatening equipment failure.] In this instance, the cockpit of the mishap aircraft was chock full of flying experience and expertise. This aircrew did an outstanding job recovering after an uncommanded deployment of life rafts attached to the C130's right wing.

One lesson worth repeating is : every time you fly, remain ' strapped in ' unless you have a need to move about the aircraft [IAW NATOPS.] It would have prevented multiple injuries among both crew and passengers.

The second ' Blue Threat ' is when the crew did not sufficiently recognize, then attempt to mitigate. an existing known hazard of uncommanded deployment of life rafts from C-130 aircraft.

There had been ( 6 ) six documented similar instances in the Hercules C-130. Effective safety processes must be promulgated and ' robust ' enough to compel recognization and comprehension of the risks of known operational hazards. Failure to do so puts the aircrew and their passengers at risk.

--Cdr. John Morrison, C-130 analyst, Naval Safety Center [ abridged ]
 
IMO, uphill is the only plausible choice in most cases where there's a significant slope as downhill will likely leave you rolling or sliding until you run into something solid. Just keep in mind that it will require substantial extra airspeed into the flare if the slope is steep.

Plus if the ground is dropping faster than the aircraft, you will never get to it.

That would make any slope larger than three degrees impossible to land on :devil:
 
Empty tanks (full of air) might float pretty well, but so will tanks full of fuel, which has a lower density than water.
Deep-sea bathyscapes like the Trieste used a huge metal "balloon" filled with gasoline for "lift". After dropping their ballast at the bottom, the tank of gasoline would carry them right to the surface. They used gasoline instead of air because it's not as compressible as air, but you get the idea.

And unlike an empty tank, a full tank won't fill with water if the vents are submerged.

But regardless of any of that, it's probably wise to exit the aircraft ASAP... how long it will float shouldn't be a factor in making that decision.
From my engineering student days..."The buoyant force is equal to the weight of the fluid displaced."

Which means, if the gas tanks are displacing 40 gallons of fresh water, you've got a buoyant force of 320 pounds. If you put 40 gallons of gas in the tanks, your buoyant force is still 320 pounds, but you're using 240 of it just to float the gasoline in the tanks. You've still got the rest of the airplane's weight (and buoyancy) to consider, but I'd say a spare 320 pounds of buoyancy would go a lot further toward keeping you afloat than 80.:yesnod:

Just one of those cases where the "FAA doctrine" is probably accurate.:eek:

David
 
From my engineering student days..."The buoyant force is equal to the weight of the fluid displaced."

Which means, if the gas tanks are displacing 40 gallons of fresh water, you've got a buoyant force of 320 pounds. If you put 40 gallons of gas in the tanks, your buoyant force is still 320 pounds, but you're using 240 of it just to float the gasoline in the tanks. You've still got the rest of the airplane's weight (and buoyancy) to consider, but I'd say a spare 320 pounds of buoyancy would go a lot further toward keeping you afloat than 80.:yesnod:

Just one of those cases where the "FAA doctrine" is probably accurate.:eek:

David
Agreed- air is better in that situation. Didn't say it wasn't.

Unfortunately, when a ditching is imminent, dumping fuel or loitering to burn off fuel isn't always an an option. I guess when it comes to ditching, it pays to be stupid enough to run out of fuel over water. :D

My point was only: "don't panic if there's fuel in the tanks when you ditch; it's not all 'dead weight'."

And again: if I ever ditch, I'll note how long the plane stays afloat from the only sensible vantage point: outside the aircraft. :D
 
Rather than trying to fly the plane into a water 'landing' they way we would on a runway, I've often wondered if it would be better to fly 5 or so feet over the water, flare, and stall, so the plane drops the 5 feet more or less flat into the water (think like our early landing attempts during primary training! :D)

I've imagined that this would be a full stall 'landing' and would have the minimum energy that you could have touching the water. And while you'd still have some forward momentum, i would hope that it is small enough not to flip the plane.

thoughts?
 
Rather than trying to fly the plane into a water 'landing' they way we would on a runway, I've often wondered if it would be better to fly 5 or so feet over the water, flare, and stall, so the plane drops the 5 feet more or less flat into the water (think like our early landing attempts during primary training! :D)

I've imagined that this would be a full stall 'landing' and would have the minimum energy that you could have touching the water. And while you'd still have some forward momentum, i would hope that it is small enough not to flip the plane.

thoughts?


Water is hard -- even from 5 feet.

I think the spine compression danger would be excessive dropping it in.

Of course you wouldn't drop "straight down" -- there would be forward momentum, and by stalling you lose control effectiveness (is the airplane coordinated? if not, may have a nasty wing drop).
 
Having ridden a Pitts S-2C into a ditching doesn't make me an expert on ditching but I'm happy to offer some observations about the incident in which I was involved.

We landed as we normally would have on a hard surface - three-point attitude getting the tail wheel in slightly before the mains and I believed that this left us with the least amount of energy to shed in the water.

We went in to the water under control and straight ahead. I think any attempt to plop in it or drag a wing tip would have resulted in a much worse result.

We went straight over on our backs and that was a total non-event. I've never understood why people think this is something to avoid or be scared of. The canopy opened just fine and though we were under water at the time had no problem getting out of the plane and to the surface. Getting out and up to the air, if you keep your cool, takes very little time. In our case, we had a 5 point harness to get off and a parachute to remove before extracting and that all took about 30 - 45 seconds of holding breath. I certainly wouldn't attempt anything extraordinary to avoid flipping over on your back.

In the Pitts, we land at a pretty high speed and went in to the water with the tailwheel first at about 80 mph. There wasn't a scratch on either of us and very little physical damage to the aircraft other than that caused by salt water immersion. It ripped the wheel pants off and form fit the lower cowling to the bottom of the engine, but that's about it.

From the moment the engine quit until we were wet, there was no time to do anything but fly the plane and attempt a restart with the mechanical pump on. Once you're in the water, the only thing you're going to have available to you is what you were wearing. You're going to have no time to find or secure anything or retrieve anything from the plane to assist you.

I'd be happy to answer any questions about anything I've left out.
 
Rather than trying to fly the plane into a water 'landing' they way we would on a runway, I've often wondered if it would be better to fly 5 or so feet over the water, flare, and stall, so the plane drops the 5 feet more or less flat into the water (think like our early landing attempts during primary training! :D)

I've imagined that this would be a full stall 'landing' and would have the minimum energy that you could have touching the water. And while you'd still have some forward momentum, i would hope that it is small enough not to flip the plane.

thoughts?

Absolutely never a good idea. You do want to touch down as slow as possible but with minimal vertical speed. I'm pretty sure you'd find that dropping in from 5 or more feet would result in a very high vertical decel (on the order of 10-15 g) and a much more rapid forward decel than you'd get with a more gentle touchdown. I also believe that you'd be increasing both the chances and violence of a flip. Finally, if you stall it's likely that one wing will stall first and if that wing catches the water you're going to cartwheel with even more violence.
 
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In the vein of "plopping it on is bad," so is the minimum controllable airspeed in some aircraft. You want to fly it on at the airspeed that sets up the proper attitude with the sink rate low. In many aircraft, the minimum controllable speed is a very high AOA and might not serve you well when going for a dip. When I land my tail wheel, it's always in a 3 point attitude with the tail wheel rolling on just a beat before the mains. If I can feel that happen, I know I've landed at the minimum safe speed to arrest the sink rate and control it. Same thing ditching. Better to roll it on than plop it in even in the water IMO.
 
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