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What makes a good field for emergency landing

Cirrus at a 45 degrees bank angle with flaps set to 50%, multiplied that times 1.3 for safety

Following engine failure you should aim for the glide speed. If the speed is decreasing, the ASI will over-read due to lag. The stall speed will only increase in a turn if you exceed 1g, in a descending turn you can maintain 1g. You should try not to use flap until the landing area is assured but that was probably take-off flap so maybe wise to leave it.

A turnback is not 180 degrees as you discovered but closer to 270 degrees when you realign with the runway. Not an impossible turn but an ill-advised one. If you have just taken off in a Cirrus and have not retracted the flap I would not consider anything other than landing ahead within 60 degrees of track.

The stall speed will only increase in a turn if you exceed 1g, in a descending turn you can maintain 1g.

Care to re-think that?

G

Boffin at large
Various, southern UK.

The stall speed increases only if the wing loading increases, no?

If therefore you do a turn at constant altitude then the wing loading will increase, so Vs rises.

But if one does a turn during which one accelerates downwards (which is quite reasonable if doing a descending turn intentionally) then any substantial increase in Vs can be avoided.

In fact if one has height to play with, one can pretty well unload the wings during the turn and benefit from a much reduced Vs. It's a handy trick for some situations.

If the wing loading is zero then Vs=0 also.

Administrator
Shoreham EGKA, United Kingdom

So you often accelerate downwards? Or do you descend with a (roughly) constant rate of descent? Apart from very briefly as I enter the descent, I tend to do the latter - and I'll bet you do too.

What a descent does is provide "free" energy that allows the turn to be maintained without bleeding speed off through all of the induced drag. It doesn't do much, if anything, to the stall speed.

Parabolic descents, at low or zero g are of-course possible, but they're a pretty specialised manoeuvre.

G

Boffin at large
Various, southern UK.

I agree a descent does not help with Vs unless you accelerate in VS.

But this can be helpful to make a tight turn in a tricky situation - if there is height to play with.

Administrator
Shoreham EGKA, United Kingdom

A deliberate spiral dive in other words.

G

Boffin at large
Various, southern UK.

I've about 100 hours in a PA28 - so not very experienced on power, but I also have 400hrs as a glider pilot and 3 years as a basic instructor. Firstly I would 'never' advocate a turn-back following EFATO in an aeroplane. In a glider I knew I could initiate a successful turn-back from about 300 ft - In a PA28 I wouldn't consider it below 1000ft. First and most important, is to get the nose down and air-speed on. In the Cherokee after practicing EAFTO's in to the airfield from high angle approaches, the glide slope is about 40 deg. The best advice I've read is to pick an area within a 45deg cone ahead and within a 45deg slope to the touch down. Add an “In the event of engine failure” scenario to your pre-take-off checks so you are prepared and take-off expecting it to happen. As for all this guff about saving the aircraft; fine if you have time, but in the final analysis what's more important - your insurance, your aircraft, or your life? Land ahead and get the aeroplane down as best you can. Your priority is survival.

As for all this guff about saving the aircraft; fine if you have time, but in the final analysis what's more important - your insurance, your aircraft, or your life? Land ahead and get the aeroplane down as best you can. Your priority is survival.

Well, I agree of course. But there are situations in which you simply cannot land straight ahead. Take e.g. the departure from Antwerp/Deurne (EBAW) over the city and houses right after departure. Landing straight ahead means letter the aircraft crash into housing blocks or offices.

Search on Google and you will find some well known US instructors advocating to train for the impossible turn. In case of a departure from EBAW I would advocate an offset departure in order to make the turn back to the runway in case of an engine failure. You would have to make a 45 degrees turn into the wind and it should be possible to glide back to the runway.

Of course, it is not the stuff they teach you when you get your PPL. Then they tell you to land straight ahead.

Now back to my tryout. I was able to make it back but since the turn is indeed much more than 180 degrees I would need to start with a 30 degrees offset track right after takeoff. Then to make the > 210 degrees turn into the wind.

As for the airspeed, I first pitched to more than 100 knots in the Cirrus and would feel uncomfortable with an IAS close to the Cirrus stall speed. I read the above posts but it is difficult to practise as there is no room for mistakes.

EDLE, Netherlands

Aeroplus, I agree with what you say and accept that not all airfields have ideal facilities. In these cases local rules will apply. But as this thread is a student pilot's thread I don't think we should complicate the issue with individual scenarios. My comments are based on the 'average' drill given most situations. I have no knowledge of EBAW so cannot comment on that particular situation other than to advise students pilots to seek advice from their local instructors. I certainly wouldn't advocate landing any aeroplane in someone else's living room. :)

Performing a little thread necromancy here...

But in the case of retract gear planes, presumably the decision to land gear down is perfectly valid? The gear will at least provide some shock absorption - and if your options are cow pasture and not ploughed fields or crops - then surely even with a CJ6 with its spindly gear you're going to want to put it down? Given that during an unexpected engine failure we're likely to fly like crap due to the adrenaline rush, therefore the touchdown isn't assured to be a smooth one, so landing heavily gear down in a cow pasture will likely have a better outcome than landing heavily with the gear up and having nearly zero shock absorption for the spine.

Certainly when I was flying the Bonanza in the US and the engine stopped, if the target field was pasture then the gear would definitely have been down.

Andreas IOM
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