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-   -   Forced landing WITH power (https://www.pprune.org/private-flying/554561-forced-landing-power.html)

hugh flung_dung 13th Jan 2015 16:53

Forced landing WITH power
 
When I was instructing it was a normal part of our training for studes to learn how to pick a field and to fly timed circuits around it for inspection and then an approach, all assuming poor viz and low cloud. Mutterings on another thread make me suspect that this is not taught by some schools, or that PPLs don't practice it. If you don't know how to do it then it would be a good thing to practice during the next flight with an FI ...

There's a reasonable description of the procedure here: but it doesn't mention timings for poor viz - ask your FI.
Remember that field length can be estimated by flying down it and timing: 1 second equates to 100 feet at 60kt (or 125 feet at 75kt, and so on).

HFD

dobbin1 13th Jan 2015 17:40

I still teach ex 17, but actually flying it seems a bit of a waste of time due to the need to fly it well above the heights talked about in the brief. Going down to 100 ft for a low pass over the field will often lead to a rule 5 violation, at least in my (densely populated) part of the world. A low pass at 600 ft just isn't the same. I have sometimes just skipped the flying exercise and just handled it as a ground briefing.

Good tip on timing to estimate the field length.

wood73 13th Jan 2015 17:41

I learned them a few weeks back, precautionary landings.
Done them at 500 - 600 ft, then properly at the airfield over the runway.

S-Works 13th Jan 2015 17:59

Its not a a forced landing with power, its a precautionary landing..... :O

hugh flung_dung 13th Jan 2015 18:47

Bose-x: You are, of course, strictly correct. I plead senility, or perhaps I was still annoyed at the "other" thread.

Dobbin: you don't need much of an open area to do this and, as wood73 did, the final practice can be done near the airfield (but then it's difficult to convince the stude to use timings and not to cheat).

Our standard brief was:
  • Pick field and direction: as for FLWOP
  • Inspect: fly down intended landing strip at 400-500 ft AGL, note heading, use time to estimate LRA, continue into wind for 30 secs after end of landing area, pick a landmark, fly crosswind for 30 secs, pick a landmark, fly downwind for 60-75 secs, pick a landmark, fly base for 30 secs, turn onto heading, let down to 50-100 ft
  • Detailed inspection: as above, climbing to safe height after the inspection until timings say you're back on final approach
Note: use DI to estimate drift allowances on legs.

The message is that, while it's better to keep the field in sight, timings work well enough to be able to find the field if you lose it.

HFD

localflighteast 13th Jan 2015 20:10

I have no idea about the UK but in Canada it is a flight test item.
Examiner gives you scenario and you have to pick out a field, depending on scenario you fly a high and low level inspection (time permitting) before attempting to land in the field.

My comment would be that the actual physical maneuver is taught but the decision making process leading to you deciding to put it down in a field could probably be better explored

mary meagher 13th Jan 2015 20:40

Hey, dungflinger, you are just as hung up on square circuits as the rest of the noisy bunch.

In the UK anyway, glider circuits ALWAYS fly the diagonal leg. So begin with your downwind, judging the correct angle to your intended field....too high? move out, too low, move in. Then instead of carrying on downwind until you LOOSE SIGHT OF THE FIELD, you cut off the corner. And this way never get disoriented.

In the US, gliders usually share a field with power and need to fit in with the rectangular patterns, fair enough. Here in the UK, every gliding circuit (or pattern if you prefer that term) includes the DIAGONAL LEG. Much safer and works nicely for field landings.

I used to be sitting behind my student, when in the old days square circuits were flown, sending thought waves, dropping hints, and actually getting the leans, losing sight of the landing area, wondering if he was EVER going to turn on to the base leg....the new way makes so much sense. If you don't have to worry about circuit traffic in your field landing practice, try it, guys. It works.

Remember, glider pilots only get one chance to get it right. Going around is seldom an option.

worrab 13th Jan 2015 20:48

Some of the noisy bunch are quite content with a constant aspect approach.

Pace 13th Jan 2015 20:57


Pick field and direction: as for FLWOP
Inspect: fly down intended landing strip at 400-500 ft AGL, note heading, use time to estimate LRA, continue into wind for 30 secs after end of landing area, pick a landmark, fly crosswind for 30 secs, pick a landmark, fly downwind for 60-75 secs, pick a landmark, fly base for 30 secs, turn onto heading, let down to 50-100 ft
Detailed inspection: as above, climbing to safe height after the inspection until timings say you're back on final approach
HFD

All sounds great for the armchair pilot but far removed from reality :ugh:
For a start the pilot maybe in rain 1000 meter vis or less and down at 250 agl with bits of cloud passing under the aircraft ???

Another method is to pass at 100 feet down wind with the landing area on your left and tear drop back onto a final to actually land. Mary talks a lot of sense from her gliding experience.

How are you in reality going to choose landmarks which might vanish in mist or low cloud ( Reality)
It should be a procedure which is controlled and has an element of VMC and IMC built in.
anything less than an IMC procedure built in is asking for trouble because you cannot be assured of good VMC in reality

Pace

Talkdownman 13th Jan 2015 20:57

Even Heathrow Number 2 Director vectors converging downwind legs with very little straight flight on the base legs...

mary meagher 13th Jan 2015 21:06

worrab, is "constant aspect approach" another term for including a diagonal leg and never loosing sight of where you intend to plonk the aircraft? I believe this is taught in the RAF....correct me if not the case.

As far as HFD's directions for timings, etc, 30 seconds here, 40 seconds there, that to my mind is VERY CONFUSING. That would clutter up my brain at a time I need to be looking ahead and thinking and estimating present position, wind drift, height, angle. As soon as you throw in prescribed timings, you are making something complicated that is really fairly simple. Has he ever done any approaches in a glider, I wonder? and how long ago?

I used to ask my students, What is the difference between flying a circuit at the gliding club or flying a circuit into a farmer's field? and the student would faff about naming all the possibilities. The answer is, There is No Difference Except you Don't Have to worry about the Traffic. So every gliding circuit even at the home field where you have a rough idea of your height relative to your position, is a practice field landing.

Having chosen the reference point, is it moving up the canopy? You are undershooting, put the airbrakes away. Is it moving down the canopy? overshooting. More airbrakes. (some call them spoilers. They do NOT slow you down, they simply increase or reduce the rate of descent. Excellent device for accurate touchdowns.

worrab 13th Jan 2015 21:22

A (UK?) glider approach has a diagonal towards the end of the downwind and onto a base followed by a turn onto final and a straight approach. If you imagine being somewhat lazy, the turns will be less pronounced and the straight bits rather curved until everything's merged into a single turn from the end of the downwind onto the runway threshold. I believe the RAF teach the curved approach method ab initio.

Level Attitude 13th Jan 2015 21:33


It should be a procedure which is controlled and has an element of VMC and IMC built in.
anything less than an IMC procedure built in is asking for trouble because you cannot be assured of good VMC in reality
Pace,
A good reason for conducting a Precautionary Landing would be if a pilot was completely lost (especially with night and or bad weather approaching)

If, as you suggest, they are already completely in it " in rain 1000 meter vis or less and down at 250 agl with bits of cloud passing under the aircraft" I would call this a Forced Landing (due Wx) with power available to adjust the approach.

mary,
A "constant aspect approach" would involve flying a curve from downwind to just above the "threshold" - I am not sure a "diagonal" comes in to it.
Generally, I would suggest, some timing does come in to it (ie 10 seconds from the downwind point to commencing the curve) in order to more easily place the aircraft at 100' to 200' on short final (particularly with high wing aircraft) to give time for small adjustments to the last part of the approach before landing.

maxred 13th Jan 2015 22:25

Dungflinger, Mary I like that. Very clevr.

The other thread, agreed, had lost track, but the comment of 5k viz, with broken clag at 400'feet agl, is doable, is total rubbish.

Can I suggest that a lot of posters/pilots have a great sense of selective amnesia. Has anyone recently tried to find a grass strip, scud running at 400, in crap? It is very, no nigh, impossible, unless you know the lie of the land extremely well. Even then, the visual difference between 400-500-600-700-800, differs enormously. The whole visual perspective changes with every 100 feet vertical, and then add in 2 miles a minute horizontally. Tough, very tough. Add blind panic in, then the situation becomes very difficult.

I agree entirely that much more training has to be done, if only to appreciate the very different visual perspectives at low level.

9 lives 13th Jan 2015 22:46


Its not a a forced landing with power, its a precautionary landing
Well, if weather related, yes, though if mechanical, fire, etc. there could be a forced landing with power, I've done a couple.

Forced, or precautionary, the implication is that it's a landing in a place not originally planned, and it's probably a rushed, stressed decision, under deteriorating circumstances. And... aside from the mechanical/fire reason, most pilots have probably waited too long, so it's worse.

If weather caused, there's some chance that you've run up against very poor weather on at least one "side". This could seriously restrict the maneuvering space, so a "normal" circuit will not be possible, and attempting it a bad idea. A part of the practice of forced/precautionary approaches is selecting the landing spot, and setting up your own approach.

It is vital to practice these skills in a training environment. When the aircraft traffic permits (things are very quiet), students should be given short circuit, restricted maneuvering landing scenarios. Another critical aspect, is that once, with partial power, you have decided to land, do not change that decision if the power returns, fulfill your plan, that surge may not last long...

A and C 13th Jan 2015 23:28

Dobbin1
 
Quite why will a precautionry landing practice end in a Rule 5 violation ? Parts of West Sussex are very rural.

RatherBeFlying 14th Jan 2015 00:25

Precautionaries vs. Landing Out
 
Having done 8 landouts (others have done multiples more) it's a whole bunch simpler than all the folderol involved with a precautionary, which I have demonstrated to at least two examiners.

The power folks have overcomplicated forced and precautionary procedures which will inevitably be conducted under pressure.

There's so much stuff to remember that many incident pilots will be beating their brains for any missed bits of the procedure when the primary focus needs to be getting the a/c to the best available patch of ground at the right airspeed. Everything else is optional.

Generally as Mary said well, a landout circuit is the same as a circuit at the home field.

Sometimes you have several minutes. I remember spending close to an hour over a field before I was able to leave.

Other times you have to make a swift decision, especially if you suddenly find yourself lower than you really should be either because of sink:{, altimeter overreading because of pressure change from a frontal passage:mad:, or overoptimistic glide computer indications:}

Interestingly such situations commonly arise when you can't quite make it back to the field or intended runway. Much better a good approach to the field or runway you can make than trying to reach one you can't;)

Andy_P 14th Jan 2015 01:06

I am doing prec search and land this Friday as part of my training (in Aus). My understanding is we do it at the airstrip so its legal.

Re Forced landings, I have already done that. It is done in the training area and you are taught how to pick a suitable landing area and the tricks to make it a successful land. Once at 500' (on final) you know damn well if you are too low/high and if it will be a successful land.

As a student now, when coming into land from the training area I always do a normal approach with a touch and go, then go around to do a simulated forced land or a flapless approach etc. Keeps the skills up. After friday, I will also add in a prec search and land to that process.

tecman 14th Jan 2015 08:06

I quite understand why early training has to be conservative with respect to practice height for a PSL but the reality is that 500' AGL really isn't good enough. It's much better than nothing, but there are any number of things that can kick in below that point; these all require practice in energy management, to use a contemporary phrase.

My flying background has not been exceptional but I think that some gliding experience, plus landing a variety of aircraft in off-airport landings (mostly planned!), has helped develop some useful skills. I completely agree with a number of posters who point out that, in challenging circumstances, the battle is - and should be - more mental (including decision making) than procedural.

I guess it's tough in areas of high population density but I've often found that instructors in rural parts of Australia have PSL-friendly paddocks and beaches allocated, or strips that are strips in name only. With the right owner permission arrangements in place, these are invaluable to the pilot who wants some help in going beyond the basics. Like all flying, messing up can ruin your day, but a total fear of planting a typical SEP spam-can in e.g. a good paddock is misplaced.

S-Works 14th Jan 2015 08:29


Quote:

Its not a a forced landing with power, its a precautionary landing
Well, if weather related, yes, though if mechanical, fire, etc. there could be a forced landing with power, I've done a couple.
It's still a precautionary landing, excercise 17.....:ok:


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