A very bad day - unless?

[Fuji Abound]

Following on from the thread about personal minimum here is the scenario:

You are in IMC at 4,000 feet, you expect the base to be around 1,000 feet, and you believe the surface wind to be 340/15 from the ATIS when you took off about 40 minutes earlier. The chart MDA is 1,900 feet and you expect the countryside to be typical of south east England although you are conscious you are close to the north downs rising to 600 feet. You haven’t been keeping an “eye” on any high obstacles in your vicinity.

The engine unexpectedly quits.

What do you do?

Of course the AI is winding down, unfortunately its not an electric one, but the turn and slip is. You are running on the standby battery. You deal with the usual attempts to restart but it is not your day. You are also doing well and get out a Mayday, and the GPS moving map is still working fine. You are around 2,000 feet now and still in solid IMC. You have checked you cant make the nearest landing field and will be around 10 miles short.

What’s your view on creating the best chance of a successful forced landing?

I don’t know the answer - it s not one of those sort of questions!

[robin]

Does the GPS have terrain readout?

[TheKentishFledgling]

If the GPS has terrain readout, fine - go for somewhere that looks suitable!

If not, quickly find somewhere flat on the conventional map (you do have one..?), then go there with GPS.

tKF

[slim_slag]

Dive to Vne in the cloud. When you break out continue as you have practiced so many times before :)

[robin]

Not sure I'd enjoy a VNE dive in cloud when I don't know where the cloudbase is relative to the terrain, or obstructions.

It would only make sense if you could then convert the speed back to height, but then that would take you back into cloud, wouldn't it?

[Fuji Abound]

I was also thinking about the heading you would aim to descend out of the clouds on?

[bookworm]

Interesting question for me is whether, other things equal, you turn into wind to emerge from the cloud or downwind.

If the ceiling is 2000 ft, you presumably turn downwind to give yourself the best choice of landing spots. If the ceiling is 200 ft, you presumably want to emerge from the cloud at minimum groundspeed. 1000 ft? Hmm...

(Smart-arse answer to the original: I apply full power on the other engine and trim for straight and approximately level flight ;))

[bar shaker]

Is the terrain mapping on UK GPSs (296/1000) good enough to be any use in this situation? I thought it was only supported in the US.

[englishal]

I suppose if you really don't know what the land below you is like, maybe the best thing to do is to head into wind, setup for approach config (forget about best glide, as you don't know where you're going anyway) slow the A/C down as much as possible, maintain control and IF you hit anything, you're going as slow as possible. Plan to land straight ahead......

[DFC]

With no reason for not doing so - put the wind on the left wing until 1000ft AGL where one should break cloud set up on left base for something or approaching the mid downwind thus a small right turn ro even lined up with a final if one can accept the crosswind............lots of options with minimal turning (extra loss of height in turn).

If still IMC at MSA -500 then turn into wind cause it's just not your day and you are now trying to minimise personal damage!

Of course there is the posbility that it may be dark under the cloud so the landing may be a night one in poor visibility and precipitation.

Don't forget the pre-landing checks - shame to land wheels up in a 1000 acre grass field!

---

Robin,

I agree that a VNE dive is a waste of time because having put out a mayday, the max time in the air means min time in wreckage before help arrives.

However, if one does dive to VNE to exit the base the idea is not to gain height again but to maintain height just below the base while searching for a landing area.

Overall - land then crash not crash then land :)

Regards,

DFC

[Floppy Link]

And remember Bob Hoover's advice if you do pop out at 200ft agl over a sea of trees, rocks, bushes, fences and assorted agricultural implements

"always fly the aircraft as far into the crash as possible"


:mad:
which is what DFC just said above! That'll teach me for not reading properly :O

[Genghis the Engineer]

Select land flaps, bring the aircraft back to just above the stall, turn VERY slowly to as-near into wind as your knowledge allows, hold the wings level. Then if it's IMC to the ground you've maximised your chances of surviving the impact. Also into-wind, you'll cover the least terrain, and thus minimise the space you fly through in which there may be any high obstacles.

Then start looking very hard and praying for a field in front when the ground becomes visible.

I hope that if it happened to me I'd have the presence of mind to think of the first half as well as the last.

G

[Slow-Rider]

Hmm. With AI winding down wouldn't attempt any limited panel IF with an emergency in cloud purely because it adds to workload for very little advantage. Would select safe glide speed with gear down and be ready to manouevre when VMC if practical.

VNE dive limited panel with unknown obstacle location looks exciting to say the least!!! :uhoh:

[pistongone]

best chance of survival would surely be to open door and pull the rip chord or even if in a suitably equiped plane hit the brs button!!

[Genghis the Engineer]

Assuming you are thus equipped, and have time in hand...

(1) Open door, jump, pull cord once clear.

(2) Shut down engine, reduce speed to just above stall, pull BRS handle.

Incidentally, exactly what do you say in your Mayday call if you've just pulled the handle, are coming down still in the aircraft with several POB - I'm not aware of any standard phraseology for this.

G

[englishal]

Or how about:-

THREE CHUTES ARE BETTER THAN ONE, COMPANY SAYS
Igniting small charges to blow the wings off your aircraft might be
counter to your natural instincts, but one company believes it's the future in emergency technology. Aviation Safety Resources is reviving an old concept using three parachutes, instead of one, to bring down an airplane in an emergency. The wings separate from the fuselage and are lowered by their own parachutes while the cabin and its occupants float down under the main chute. The company says it improves safety by separating the aircraft from its fuel tanks, particularly important during in-flight fires, and reduces the weight the main chute needs to carry. The concept was successfully tested in 1967 on a Stinson over New Jersey.
Aviation Safety Resources owns the patent for that device and plans to market the idea to general aviation and the airlines. Check it out for yourself on the Web site ( http://www.aviationsafetyresources.com ).

[High Wing Drifter]

Given that scenario it would be sensible turn to what I think is north away from concentration towns and, hopefully, away from hills and to the flat lands. Pending a semblance of stability and control, definately mayday to get DF position. Vectors would probably be useless as the DI would have started to loose any accuracy almost immediately.

Mustn't forget to turn all superfluous electrics off to get as much battery time as possible...esp if electric flaps.

Q for GtE: Why landing flaps? My thought would want to reduce the possibility of sink, even if I am 5-10kts faster. Maybe one stage of flap?

[englishal]

5-10 kts could make the difference between life or death if you hit something.......what is it that road safety ad says on telly?.....at 40 miles per hour, you have an 80% chance of killing me......at 30 mph I have an 80% chance of surviving........ You won't sink unless you get too slow.

[Slow-Rider]

Mustn't forget to turn all superfluous electrics off to get as much battery time as possible...esp if electric flaps.

Agree in sentiment but should have about 20mins on the battery and from 4000 ft you'll be on the ground within about 5 so I'd fly the plane over faff with load sheading. Besides when you action the remainder of a Forced Landing Drill you should turn the battery off after final flap selection.

[CosmosSchwartz]

Vne dive to break cloud. Doesn't really reduce time in the air as you have all that speed to bleed off, but it does increase the time you have to pick a spot to land.

(Based on the scenario of cloud base at 1000ft and high ground 600ft. If cloud or ground is unknown then all bets are off!)

[slim_slag]

Indeed Cosmos.

OK, for the rest of you, if you don't feel competent enough to do a Vne dive then dive at Vno.

There isn't a decent answer to this question, you are up the creek without a paddle, if it's cloud all the way to the ground you are screwed. If there isn't cloud all the way down you want as much time as possible when you break out. Would you all agree on that?

[Genghis the Engineer]

Q for GtE: Why landing flaps? My thought would want to reduce the possibility of sink, even if I am 5-10kts faster. Maybe one stage of flap?
Two reasons, firstly if the engine has stopped and I am going to hit the ground anyhow it makes little difference to me whether that's in 4 minutes or six. Secondly, land flaps will make the descent angle steeper (thus reducing the risk of hitting a mast) and stall speed as low as it'll go, so my energy when I do finally hit something is as low as possible.

OK, for the rest of you, if you don't feel competent enough to do a Vne dive then dive at Vno.
Again, I'm descending anyhow, why risk loss of control by doing it in anything other than a sensible low speed / lowish sink descent. If I come out of cloud at Vs+5 at 100ft, or at Vno at 100ft, my odds of controlling the ground impact in a reasonably horizontal manner are far better at low speed. This is for the very simple reason that a significant amount of height is lost in changing from a fast dive to horizontal flight.

If I know that I'm going to come out at a reasonable height above the surface, I'd use min.sink, but if I don't, I'll stick with Vs+a_little_bit since that's the best thing to hit the ground at.

G

[Timothy]

Thank you all for reminding me why I send the children up chimneys and the wife on the streets so that I can afford to operate a twin.

[yawningdog]

I agree with Slow-Rider on this except for one thing,

- Select the book glide speed for forced landing.

- Do not attempt any turns in IMC. Too risky, no available power to fix any errors.

- Do not select gear down or any flap until you actualy see a landing zone.

The extra drag from gear down is huge. Landing wheels-up shouldn't cause any extra risk.

[bookworm]

Thank you all for reminding me why I send the children up chimneys and the wife on the streets so that I can afford to operate a twin.

Oh that's how its done! And here was I thinking that it was more efficient to make them pedal...:)

[Miserlou]

A word of warning about this 'expect the cloud base is...' business. Psychologically your building in a potential overload, ie. when you get to 800 feet and you haven't broken out yet and you don't have a plan for the last bit. Stress, stress, stress!

Also I would suggest that, bearing in mind that you may not be as current on partial panel as you should be, one would perhaps be best served by keeping the workload as load as possible. That it to say continue with the trimmed speed until you are stable in the glide then perhaps slow down gently to min sink and head into wind.

Those two items will put you in the most survivable situation you can hope for in your current circumstances.

[Andy_R]

Thank you all for reminding me why I send the children up chimneys and the wife on the streets so that I can afford to operate a twin.

Nice one :p :}

A word of warning about this 'expect the cloud base is...' business. Psychologically your building in a potential overload, ie. when you get to 800 feet and you haven't broken out yet and you don't have a plan for the last bit. Stress, stress, stress!

Having been there (albeit with an engine) I can vouch for that. Nothing is worse than expecting to break out of cloud and then......... not. The stress levels rise incredibly and can only affect your performance adversely.


Reckon I would go with the Vs +5 option. At least if you do hit something you will have reduced the amount of energy available to cause you damage.

[High Wing Drifter]

Two reasons, firstly if the engine has stopped and I am going to hit the ground anyhow it makes little difference to me whether that's in 4 minutes or six. Secondly, land flaps will make the descent angle steeper (thus reducing the risk of hitting a mast) and stall speed as low as it'll go, so my energy when I do finally hit something is as low as possible.
Thanks for taking the time to explain. I think I understand the effect of flaps. But you mentioned turning and I assumed that you would wish to stay airborn for as long as possible or until you decide its time to descend. My understanding and limited experience is that although landing flaps (i.e. much drag) would reduce your landing speed, they would also reduce the controlability of the aircraft. I think I would always maintain a configuration that would allow me to extend the glide for as long as possible until the point where I think I have a chance. Adding flap (esp with a PA28) is usually easy. Taking it off is invariably won't be. Maybe electric flaps pose problems with this particular scenario.

[Thumpango]

Umm.. think I will stick with VFR and keep well away from cloud.

this IMC lark sounds far too risky!:ooh:

[GusHoneybun]

One for the engineers amongst the assembled masses.

Exactly how quickly would the AI and DI start to wind down to give spurious information? Also, as the vacuum pump is linked to the engine, and your prop is windmilling then would this still be driving the pump? and would there enough suction to provide a 'useful' AI and DI.
Just wondering because the initial reaction to anything this serious would be to believe your instruments, which could present even more problems when you do break cloud inverted! Vne or not, not much time to get sunny side up.

Tis a silly thing to do anyway.....

[yawningdog]

I would suggest, if the engine quits, then don't believe anything that requires the engine to be running. That simple. So transfer over to limited panel ASAP, & cover up the AI & DI if poss.