Short field landings on C150 and Boeing 747's.

[Hudson]

If the Cessna landing charts state 54 knots approach speed to meet book landing length figures, then presumably the IAS is based on standard 1.3Vs. If this is considered a short field landing speed, then what is normal landing speed?

I presume there is no difference? If that is correct, then would it be correct to state that all jet transport landing speeds with normal landing flap and flown at Vref (assume no speed additives due wind) are by definition short field landings - assuming runway length limited? Is there such a term as "normal field landings".

Going one step further, why do flying schools require students to be competent at short field landings, when larger passenger carrying aircraft do not do short field landings? - only "normal or non-normal" landings?

I thought that the original concept of "short field"landings was a wartime technique where the aircraft approached hung on the prop blast, at a couple of knots above the power-on stall speed, when landing into unsurveyed fields of unknown length.

Therefore, are flying schools who teach "short field" landings, sticking their student's neck out by teaching an old wartime bit of trick flying which has no peacetime application. Because if Boeings and Barons don't do short field landings, why do ab-initio students do them?

[Kermit 180]

We teach short field landings. In NZ there are many fields that warrant such an approach. It could be argued, however, that if you require such a technique, should you be going into that field in the first place?

54 KIAS with full flap is the approach speed for such a technique. The 'normal' approach speed is stated in the AFM as being 60 KIAS.

Kermie :)

[Final 3 Greens]

Hudson

One good reason for mastering this technique is to be able to use it to execute a precautionary landing into an unsurveyed field, e.g. in the event of weather closing in.

However, I do agree with you that careful flying is required to maintain safety.

[Kermit 180]

As for the Boeing, I presume there would be a technique for a short approach, but I waould imagine most of the 'short field' (if you can call it that) stuff would be done with the brakes and reverse thrust once the aeroplane had landed.

Kermie

[Hudson]

Kermit. As far as I am aware there is no short field landing technique in Boeings. All approach and landings in transport category types such as the 737, 747 et al, are either normal or non-normal (one engine inoperative, hydraulic failures etc).

The Cessna AFM that you mention must be a locally produced one as the copies that I have for the Cessna 150 which are from the manufacturer indicate 54 knots approach speed power on or power off. Unable to find any reference to 60 knots being the speed on which the landing lengths are predicated.
Makes stuff-all difference really, I suppose!

[Final 3 Greens]

Hudson

I guess the guys who route plan for the airlines calculate the required field length using public transport factors and then see if the heavy iron will fit, bearing in mind the variations in the supporting factors such as density altitude, weight etc.

If it does, the guys on the day will then select the appropriate flap/brake/reverse thrust combination and stop accordingly!

Presumably, the other side of this equation is the decision how much to flex/de-rate on take off.

I haven't actually flown big stuff, but I have had some good sim sessions with a line training captain and one of the points stressed was the ability to touch down consistently so that we did not go throught the virtual hedge at the end of the runway, as the guys at base anticipated accurate flying skills from their pilots when working out what would work!

Out of interest, I have just looked at both the POHs that I have on the shelf (SA120 Bulldog and B121 Pup.) They both mention "Normal Landings" and "Balked Landings" (i.e. those requiring a go-around.) The Pup also discusses "Crosswind Landings" - although this is merely to confirm that these have been demonstrated up to 25kts and that the nosewheel steering is effective in keeping the aircraft straight.

Perhaps "short field" landings are something that the US manaufacturers like to declare. I have certainly seen references in Piper manuals, but do not have one to hand to quote.

Interesting thread Hudson.

[Richard49]

Don't know about the Cessan 150 but for our club Cessna 152 Aerobat, we use 54kts and full flap for a short field and 65kts 2 stages of flap for a normal runway.

Since the MTOW for 1 C152 is 1760lbs and ours is 1282lbs unladen weight we are probably over limit with just two people on board and enough fuel to do a circuit.

When you consider that we fly into a number of grass strips, it just makes good sense to use a short field approach, it really is very embarassing to see the end of the runway approaching rapidly and still be travelling at 20kts+

[john_tullamarine]

Might I suggest the real problem is that many pilots are trained on, and then regularly fly from, longer runways.

Then, at some stage, they have to contend with the novel situation of a short strip with a length in the vicinity of the aircraft's landing performance limits.

If the said pilot has been trained, and is habituated to, landing at excess speeds, then he/she may well find that his/her blood pressure rises in inverse proportion to the rapidly (inadequate) disappearing distance remaining until the bumpy bits start.

Why people persist in operating light aircraft at speeds well in excess of the book landing speed continues to intrigue me.

I find it particularly alarming to see aircraft then float for a significant proportion of the runway before touching down.

Hudson and I have quite aligned views on this subject.

[Squawk 8888]

I thought that the original concept of "short field"landings was a wartime technique where the aircraft approached hung on the prop blast, at a couple of knots above the power-on stall speedHudson, that technique was referred to as "soft field" where I trained. The idea was to apply extra power during the flare to bring the wheels down gently enough that they don't dig in. It has its uses even on paved runways, especially when landing with a flat tire or other damage. I know one instructor who used it after a midair collision left the nose gear hanging by a single bolt. It's also a useful way to recover from flaring too high.

[chicken6]

Richard49

I used to teach on C152s as well and we used to use 54kts over the threshold with no power and full flap for the short field landing, or 60 knots with 1500RPM and full flap for the normal approach. We (the instructors at least!) definitely noticed the 6 knots difference in controllability especially when landing in a decent crosswind on a short grass runway.

It seems the loss of 10deg flap from the C150 to the C152 made some noticeable difference to a speed after all! I didn't think it had (haven't flown the C150).

And as Kermit180 said, in NZ the weather can change so damned quickly that sometimes you actually can't see it coming and it's better to pick your landing spot rather than get into cloud and live through the 30(?) seconds. In this case the best place may be the least bad place, so we need to give our students (and possibly future charter pilots) the chance to see how short it can be landed and stopped and the best way of doing it.

To answer Hudson's last question from the first post then, my answer would be "because in the next 50 hours they're not going to get the chance to kill anyone in a Baron, but they will get the chance in a C152/PA38/PA28. When they get to Baron stage, they'll have a better appreciation for hard stuff and speed control. When they get to 747 stage they'll have a grumpy old captain there to tell them off at 10 miles when they're 10 knots too fast and they won't get the chance to stuff up."

[Kermit 180]

Sorry to be picky here, but as we're being 'exact' the MTOW for the C152 is 1670-lbs, not 1760-lbs.

Kermie http://www.stopstart.fsnet.co.uk/smilie/hitler.gif

[Hudson]

Squawk 888. THe wartime short field (really really short field, that is) may well be, as you suggest, to cover the soft ground landing. I have not seen this technique mentioned in any C150/172 POH, although a soft field take off technique is stated.

Carrier landings in Naval fighters such as the Sea Fury are classic short field where the approach is carried out on the point of stall hanging on the prop. I know that well, as I damned near bent a Sea Fury doing the same type of landing on a hard surfaced runway. But my understanding of civil regs (certainly in Australia) is that you are legally required to use the manufacturer's aircraft flight manual speed for landings. Anything less than that, you would nailed by the insurance sleuths and the operations inspector if you were caught or bent something.

As John_ Tulla said earlier, if correct flight manual speeds were taught to students right from the word go, then there is no fear of 1.3Vs. Is there anyone using say 45knots approach speeds in a C150 for short field landing? Because I know of one operator that teaches approaching with stall warning blipping in and out at 45 knots.
I see that as potentially lethal, like practice turn-backs following simulated engine failure.

[Hudson]

Richard 49. Ye Gods man! 65 knots and only two stages of flap in an Aerobat! That must give one hell of a long float if the intention is to touch down on the point of stall. What is the point of all that extra IAS? Surely full flap and 54 knots flight manual speed is perfectly safe, otherwise the aircraft would not receive its certification.

That was the point of this thread. Flying schools using artificially inflated appoach and landing speeds and calling them normal speeds. Then calling a 1.3Vs flight manual speed a scary gut-churning short landing speed.
Seems crazy to me, teaching bad habits like all these extra knots for Mum and the kids syndrome..

[I Fly]

If you are training in Australia then the Day VFR syllabus requires landing, cross wind landing and short landing. My C 152 Information Manual Part No: D1190-13-RPC-4100-9/82 states: Normal Approach, Flaps up 60-70 KIAS. Normal Approach, Flaps 30 55-65 KIAS.
Short Field Approach, Flaps 30 54 KIAS, the CASA P chart are based on that. I teach Flap 20 and 65 KIAS so that the early student has slightly better control responsivness. I also asume Cessna might know.

[Final 3 Greens]

Hudson/John Tullamarine

I am with you on the subject of approach speeds.

Yesterday I did an insurance check ride for an Arrow IV; I have 160 hours on PA28s, mainly the tapered wing 180-200hp types, so I'm quite comfortable with their characteristics and capabilities.

Anyway, the POH quoted 53kcas for stall with flaps 40 at gross and we were within 50lbs, so I worked out Vs0 x 1.3 to be 68.9, deciding to use 70 over the fence as my target.

I did this for the first circuit and was then asked to demonstrate a flapless at 75, no probs.

The instructor then asked me to finish with a short field landing (without demonstrating maximum braking effort), so I again landed using 70.

Anyway, he must have been happy as he signed me off for the plane, but the only difference I could perceive was that I had got a better feel of the aircraft by the third time and put it down 30-40 meters nearer the numbers than the first time.

So what is the difference between a short and normal landing? I treat every landing as a 1.3Vs short final and then brake on merit depending on the runway length (no point casuing excessive wear when gentle braking is safe.)

I know that I would start to feel uncomfortable flying a PA28R below 1.3vs, because I once accidentally did it in the US in an Arrow calibrated in mph, by flying Kt v-speeds; I'm still here but the handling was so appalling that I thought I had a control problem (I did, me!) and we must have been right at the back of the power/drag curve.

[Richard49]

Hudson ....

I guess it's horses for courses and depends upon the Airfield you are flying in and out of. Firstly our C152 is fully IFR equippped and weighs in at 1282lbs (unladen). Now figure it our for yourself with a MTOW of 1670lbs, put 2 pilots on board and some fuel to go somewhere and we are almost always over the MTOW (not as previously mistyped 1760lbs)). Our home strip is a 1367m tarmac runway and we use 10 degree of flap and rotate at 50kts for take off.

Of course we do use 30 degree of flap and a 54kts apporach speed for short fields - perhaps it's the effect of the additional weight but certainly the approach speeds and stages of flaps given seem to result that we arrive over the numbers at around 20' above the ground for a nice round out and flare for a straightforward landing, there really doesn't seem to be too much float on that approach and of course the additional speed does mean the aircraft is more responsive and once you close the throttle the excess speed seems to die off pretty quickly.

I didn't make these figures up, they are the ones set down by the CFI at the club and we adhere to them - however on another point - we also use a 3 degree approach path and on another forum other's insist that a 5 or 6 degree approach path is much better (again the argument seems to be use full flap) what are others opinions on this - again I would stress that this is for our home Airfield and we do vary this according to the field we are visiting.

Interestingly enough we have also just acquired a Grumman Tiger and reading around the Grumman flyers web sites, they seem to say that a 3 degree approach and 65kts is the way to fly them in

edited for typos

[ 19 August 2001: Message edited by: Richard49 ]

[I Fly]

As this is the Instructors forum, I am wondering what we are teaching our students with quotes like "we are almost always over the MTOW"???????
The insurance company will be very pleased that you are paying them a premium, but don't expect getting paid if you have an accident. I don't intend to DONATE one cent to them.

[Wheeler]

I can recall flying 152's in the UK, no-one ever seemed to bother too much about being a bit overweight - and must have been at times with 2 big blokes, full standard tanks, dual navcoms, ADF, DME, transponder etc. Never had a problem, but I hate to see it now and would not condone anyone doing it.

Teaching short field landing is a great idea if only to stretch the student a bit and let them know they dont really need to run off the end of 1000m of tarmac. Isn't it about a little more accuracy and precision? 54kts, full flap, throttle closed.

[TheSilverFox]

SQUAWK 8888

"A useful way to recover from flaring too high"

Surely it would be safer to encourage your sdudents to initiate a 'Go Around' in those circumstances.

On that point, I think that some schools teach the 2 stages of flap approach to assist in student go-arounds incase in the heat of the moment they forget to raise the third stage.

[Squawk 8888]

Point taken Silverfox but I'm talking about those flares that are only a wee bit high and not wanting see the pax crush their teeth. I've executed go-arounds from the flare but sometimes the soft-field technique of goosing the power during the flare makes it look like you were planning it that way all along- an important factor if one's passenger happens to be female :D

[Hudson]

Having come off the big jets back into GA, it puzzles me to find that on the heavies the landing configurations and associated IAS are strictly standardized for each aircraft type, whereas one finds that in the world of GA instructing, each flying instructor teaches his/her own pet ideas on speeds and flap settings. Must be a fiscal nightmare for students who switch schools or instructors and have to pay to relearn "new" ideas on how to land a C150 et al.