I noticed the post below on a forum about night flying. The wording of each paragraph has been changed so as not to infringe any copyright but the gist is the same.

The author is advocating never flying a 3 degree G/Ps at night seemingly based on the fact that if the engine stops on finals you will not be able to glide to the airfield.

I always understood that any licenced airfield had to have some form of angle of slope indication for night flying?

What slope angle do you use for a night approach and for what reason?

Are PAPI's 'The Devils Instument'?!

Do you fly circuits at night so you can always reach the runway in the event of an engine failure?

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Turning final two miles from the runway then you should still be at a thousand feet QFE.

Turning final about one mile from the threshold at about 500 ft QFE to conform to the normal circuit procedure.

If the airfield at which you learn has stupid NIMBY type bomber circuits then these figures may not be appropriate.

PAPIs are OK for multi engined aeroplanes but for flying an instrument approach in a single engine aircraft they are regrettably where you will end up.

For any visual approaches in a single engine aircraft they are the devils instrument.

Try flying a few circuits with the PAPI’s switched off.

At some stage you will fly to an airfield without PAPI’s at night and you should possess the necessary skill and judgement to be able to fly an approach without them.

:hmm:....It's never occured to me to fly night circuits in a different way to day circuits...although I can see the sense in always being able to make the runway. But if you are going to take that line then you'd never fly a 3 degree glideslope in a single ever, or leave the circuit at night at all.

As far as PAPIs are concerned...well I've never really found the need for them during the day or night and I think night training should include landing without PAPIs.

I fly a normal circuit.

As you move from grass strips to lighted runways to runways served by an instrument procedure, the slopes of the obstacle free approach areas become less steep.

If you do all your night training at PAPI served runways and subsequently fly at night to a runway without one using the same approach slope you are used to, you might just hit something before reaching the runway.

Similarly a one in ten gradient may accommodate an engine failure privided there's no headwind -- not much room for error in your typical SEP.

Steeper approaches at night give you a better chance at missing the trees. I've yet to see a tree lit to ICAO standards:}

Well for sure it is easier to go around if your approach was to high than to go around after you hit the trees because your approach was to low.:E.

Steeper approaches at night give you a better chance at missing the trees. I've yet to see a tree lit to ICAO standards

Of course the night training syllabus includes approaches with all kinds of lighting failures, including the PAPIs.

Our aerodrome has a 4.5 deg glideslope to ensure obstacle clearance and the APAPIs are set for this. My 'normal' procedure is to fly the circuit as per during the day, but it is a rather special circumstance, being 750' QFE and having a 750M runway, with trees on the approach. You're pretty much limited to accurate flying of the standard cct & app. The aerodrome limits night flying to those with considerable experience and annual checkouts and a written list of those approved for night flying.

No, PAPIs or APAPIs are NOT instruments of the Devil! Ours are turned off during the day so that we can train people to use the proper runway aspect to guage their approach slope, but are an essential at night to guarantee missing those pesky trees on short final!

Engine failures at night in a single? Well, I don't think that it's any more likely on the approach than in the cruise, so the risk is no greater. The most likely time for an engine failure I believe is just after takeoff when it's flogging away at its hardest. If you check your fuel and do your power checks properly, then you're going to be REALLY unlucky to suffer. I can't recall a case of engine failure in a single at night except due to fuel starvation, so statistically from that regard it's safer flying at night than during the day!!!????
Cheers,
TheOddOne

The safest way to fly is by doing the same thing all the time - so that when the workload is high (night/poor wx) then you are operating in a way that is second nature.

Therefore, the safest way to fly a night circuit is the same way that you fly a day circuit, just in the dark! if the daytime techniques don't work once the sun has gone down then there is something wrong with the daytime technique. The last thing needed in a higher workload environment (night) is to do something that is not familiar, as this will crank up the workload still further and increase the risk of an error.

3 degrees for multi....5-6 for single and applies to both day or night

Steeper approaches at night give you a better chance at missing the trees. I've yet to see a tree lit to ICAO standards

But on that basis all large commercial traffic would fly higher glide paths as they tend to take forests out rather than individual trees!

for the first 1-3 circuits

BADLY

My instructor told me to flare once we had the runway illuminated by the landing light. On the second circuit, somewhere on downwind, the landing light broke. Fortunately we were flying a PA-28 with those low-power wingtip recognition lights fitted as well, and as soon as we saw the runway illumiated by those, we just both yanked the control column simultaneously, just enough to cushion the landing (arrival, actually) and save the plane.

Some of us find it easier to land without a landing light; however it is useful to let whoever is on the runway that you are about to use it.

As for animals, think deer in the headlights.

Landing lights do advertise your presence and once gave me sufficient warning to duck my head below the panel before hitting a bird:ouch:

I only follow the PAPI when following heavier aircraft on final (Small bizjets and up). Assuming that the plane ahead of me is flying 2 reds, 2 whites; I can stay at 3 white, 1 red (or 3 w and 1 pink :}) and be absolutely postive that I will stay above the wake...

I only follow the PAPI when following heavier aircraft on final (Small bizjets and up). Assuming that the plane ahead of me is flying 2 reds, 2 whites; I can stay at 3 white, 1 red (or 3 w and 1 pink :}) and be absolutely postive that I will stay above the wake...

Best way to avoid wake is the time/distance method

My instructor told me to flare once we had the runway illuminated by the landing light. On the second circuit, somewhere on downwind, the landing light broke. Fortunately we were flying a PA-28 with those low-power wingtip recognition lights fitted as well, and as soon as we saw the runway illumiated by those, we just both yanked the control column simultaneously, just enough to cushion the landing (arrival, actually) and save the plane.

Some of us find it easier to land without a landing light; however it is useful to let whoever is on the runway that you are about to use it.

As for animals, think deer in the headlights.

Landing lights do advertise your presence and once gave me sufficient warning to duck my head below the panel before hitting a bird

In Canada at least, a working landing light is mandatory for carrying passengers at night (hmm, not sure if the regs say you actually have to use it!).

In any event landing lights can and do fail. Every 6 months I do 5 or 6 night circuits to keep in shape if I haven't done much night flying lately, and I always make sure I do one approach without landing light. My Beech has a single 250 watt light in the wing and it's much more effective than the little candle behind the prop on my previous PA28, so I miss it more when it isn't working.

Assuming that the plane ahead of me is flying 2 reds, 2 whites; I can stay at 3 white, 1 red (or 3 w and 1 pink :}) and be absolutely postive that I will stay above the wake
Wake vortices descend at 300-500fpm so following the "glideslope" should avoid them.

I find night circuits are best flown like day circuits: accurately by the numbers w.r.t. altitude and position. However, while in the daytime I would fly a steep final (because it's much easier than a 3 deg slope, and much safer, with more options) at night I would follow the lights.

However I rarely fly at night enroute - it leaves no escape route for an engine failure.

Wake vortices descend at 300-500fpm so following the "glideslope" should avoid them.

Where's that figure from?

G

Some tips from the CAA Safety Sense Leaflet

• Wake vortices are generally invisible.
• Vortices last longer in calm or light wind conditions and are therefore at their most hazardous then.
• They are most dangerous close to the ground.
• The heavier an aircraft, and the slower it is flying, the stronger its vortex and the greater the risk to following aircraft.
• The lighter the aircraft you are flying, the more vulnerable it is.
• When an aeroplane’s nosewheel is on the ground, there are no vortices.
• On departure, use the appropriate time interval when following a heavier aircraft –
2 minutes if starting the take-off at the same point,
3 minutes if taking off part-way along the same runway.
• When taking off behind a departing heavier aircraft, note its rotation point so that you can lift- off before that point and climb above the vortex. If you cannot – WAIT.
• On the approach, avoid vortices by flying above and upwind of the lead aircraft’s flightpath.
• When following a heavier aircraft which has already landed, note its touchdown point and land beyond it. If there isn’t room – GO AROUND.
• Apply the spacing advised by ATC, using runway length as a guide to judging distance.
• When following a large helicopter consider allowing a bigger gap than for the equivalent sized aeroplane.
• Keep well away from helicopters with rotors turning, they may be hovering or hover taxiing – it can be difficult to judge.
• If in doubt – WAIT.
• All encounters should be reported.
Full details are published in AIC 17/1999 (Pink 188), ‘Wake Turbulence’

GTE

I did a quick google on

wake vortex descent rate

and found a few hits; one is an IEEE paper which needs a login (no idea how google has managed to index it) and there are others.

Wiki (http://en.wikipedia.org/wiki/Wake_turbulence)has a figure for you.

no idea how google has managed to index it

Either they gave Google a login, or they've got a website which doesn't require a login if the browser identifies its type as being "Googlebot" instead of IE, Firefox or whatever. Oh, and some browsers allow you to set their type manually to fool the server. 'nuf said, try it, it might work.

Still leaves me wondering why the IEEE would be interested in wake vortices though. Can't see the relation with those and electric and electronic engineers.

My AIP recommends flying above the aircraft ahead and touching down further down the runway. So I prefer flying 3 or 4 whites following heavier airplane espesially when ATC squeezes me in between traffic.

Google scholar is quite a good tool for accessing paper abstracts and citations - then those with the required access via something like ATHENS can get into the full paper text, or those who don't can go and find it in a good library.

The major engineering institutions often publish a lot of stuff outside of their apparent main subject matter. I've published aerodynamics paper in an IMechE journal, and I believe that a lot of aeronautical stuff is published in the USA by ASME - the American Society of Automotive Engineers!

The theoretical disparity between engineering disciplines is mostly nonsense anyhow!

G

My AIP recommends flying above the aircraft ahead and touching down further down the runway. So I prefer flying 3 or 4 whites following heavier airplane espesially when ATC squeezes me in between traffic.Only problem with that is that at some stage you will fly through the flight path of the other aircraft unless you touchdown after its touchdown point.(as you say) Correct time and distance spacing means the above dosnt matter. Your advice is good Birk but dont forget to add/consider--fly to the upwind side as well

I can remember doing my night rating in the 80's from Woodvale using paraffin goose necks to indicate the position of the active.

One line of lit lamps down one side of the runway and a box formation to indicate the threshold. And that was it.

On my return to the field following, my solo night cross country. The weather had changed slightly and rain and wind had started to extinguish the goose necks. I flew the approach with the lights going out one by one!

On finals my landing light went out and then came on again on touch down.

Very eventful!!!

Are Cliff and Stan still around?

Cliff passed away and Stan retired to his farm to count the pennies.

Some of the members got together and raised the funds to build a new hangar. But this is just for private use.

Jim SATCO also passed away, Primo still flying but Paul Kelly now concentrates on IT. Clarky still flys biz jets out of Manchester.

Happy Days

I just look out the window and fly a constant aspect when VFR. When IFR on an IAP it is done for me.

Nothing like the flight back up from Guernsey at night and with only one engine.....

I am chief lighting engineer at our place, 16 garden lights on a pilot operated switch. No PAPI and you have to make sure you aim for the second pair in on the westerly end or you will clip the hedge.

When I did my Night Rating I was taught to land without the landing light, as they had a habbit of breaking on the PA28, did it at Biggin, did quite a few circuits with the PAPI's turned off, I was taught that when the runway lights where about shoulder height you were on the ground,got pretty good at landing without the use of a landing light...taxiing with out it, that was impossible at Biggin at night!

but dont forget to add/consider--fly to the upwind side as well

Please explain that when the wind is straight down the runway.

The ICAO advice on wake is better than the CAA's version of it and provides clearer examples.

A word of caution regarding using a slightly high indication on the PAPI to avoid wake. Fly with 1 white, 3 red / 2 white, 2 red / 3 white. 3 red will all take you to the same point abeam the lights the only difference is the angle of approach. Thus while using a slightly high indication at say 3nm will have you above the wake of a B737 which was on slope, as you get closer in, you will get closer to the wake until you are at the same level at the PAPIs.

The B737 nose wheel will not be on the ground at that point so it will still produce wake. Combine that with a little crosswind and the wake will be waiting for you at about 20ft..........just the height you wanted to be inverted at!

Far better to use the PAPI to asist you in establishing on final above the normal glideslope and having done that, pick your touchdown point suficiently beyond the papi and make a constant aspect approach to that point.

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Night circuits at a licensed aerodrome are flown in the same way as day circuits. PAPIs where available ensure obstacle separation within the coverage when used properly. The important thing is to never fly below the on slope indication ever. How much above that you want to fly is up to you provided there is a stable approach to the correct threshold crossing height.

I do however agree that many training night circuits should be completed without PAPI or landing light.

If a tree passes through the obstacle limitation surface or is a significant obstacle then it will be either removed or lit at night where the aerodrome is licensed. The usual way to light a tree is to place a pole in an appropriate place with the light on top which shows where the tree is.

Regards,

DFC

but dont forget to add/consider--fly to the upwind side as well Please explain that when the wind is straight down the runway.

Because of the moonbeam effect, cyclostrophic effect and geostrophic effect not taking diurnal variation into consideration the wind on the approach will not be in the same direction of that on the runway.(plus it must be Thursday night because thats night flying night)

The only problem about flying above the PAPIS is how do you know the 747 ahead wasnt flying above them too, i wouldnt want to take that chance would you?

The only problem about flying above the PAPIS is how do you know the 747 ahead wasnt flying above them too, i wouldnt want to take that chance would you?

You are correct and of course, one can only use that method (keeping above the otehr aircraft's approach) if you have actually seen the aircraft fly the approach and can judge their height versus distance from the threshold.

That is why I say just giving oneself an extra white on the PAPIs is not suficient. Flying the average cessna or piper or other light aircraft including the twins, it is easy to make a (what would normally be termed) steep approach and guarantee that (unless the B737 went round for an unstable approach) one is above the wake.

Regards,

DFC

You are correct and of course, one can only use that method (keeping above the otehr aircraft's approach) if you have actually seen the aircraft fly the approach and can judge their height versus distance from the threshold.

Just to add to that DFC often on the approach to LHR we comment, "what is he doing in front", usually bongo airlines seemingly with their own glidepaths!!!

I can remember doing my night rating in the 80's from Woodvale using paraffin goose necks to indicate the position of the active.

One line of lit lamps down one side of the runway and a box formation to indicate the threshold. And that was it.

On my return to the field following, my solo night cross country. The weather had changed slightly and rain and wind had started to extinguish the goose necks. I flew the approach with the lights going out one by one!

On finals my landing light went out and then came on again on touch down.

Very eventful!!!

I did my night rating in a similar fashion. A 2800 grass and gravel field north of the Ottawa River, now defunct, called Saint-Andre-Avellin. We would set up flare pots along both edges of the runway. The threshold was where the flare pots started. We would light them, the fly to nearby Gatineau, a proper airport with landing lights, isntrument approach, etc, to do practice touch and goes.

On the night I did my night cross country, we made a long flight out of it with 1 instructor and three pilots. First one flew to YQB, second to YUL, and I had the honour of doing YUL-YOW and then home (which means I got the extra landing). When we neared home, we used a lighted tower as a reference point to find the field (no GPS in 1981..., and no navaids at the field either, but we did cross two VOR radials to confirm our position). We couldn't see the tower. We turned on the landing light and were met with a wall of fog. We quickly turned tail and landed at YOW with increasing fog and lowering ceilings (none of which were forecast). We returned to the field by car (instructor's father came to fetch us). I ended up arriving at home at 5 am.

Ahh, the memories. We were young and crazy, flying over bush and lakes at night in a 172 with the notorious H3AD engine... at least it was a brand-new aircraft.

I fly a normal circuit as well for night.

J.

Just to add to that DFC often on the approach to LHR we comment, "what is he doing in front", usually bongo airlines seemingly with their own glidepaths!!!

I've made that comment many many times on approaches to smaller airfields. So often, the traffic ahead is crawling maybe 200ft above the ground for most of the final, and/or is so far to one side they "cannot possibly" make the runway but somehow they manage to get back onto it.

Rarely do I see someone doing what looks like an overly steep approach. Most of the weird approaches on the GA scene seem to be at something like a 1 degree "glideslope" :) No wonder some people hit the ground if they try that at night.

I can remember doing my night rating in the 80's from Woodvale using paraffin goose necks to indicate the position of the active.

One of the most wonderful sites in aviation is a runway lit by gooseneck flares, the last time I landed on such a runway was Kidlington in 1975, are there any club airfileds still using goosenecks?

maybe 200ft above the ground for most of the final

That's just called the "flare".

(At least, that's the excuse that I would use.)