Operating Sally b or PA474 from a grass landing field?

CWH definitely will operate away from Hamilton – they spent the weekend at Reading airshow with the Lanc based there from Friday afternoon to Monday, as I recall. I don’t think their restrictions are stupid – they have a museum that has to pay its own way, and it think it’s fair to say the Lanc is the central exhibit. They previously had the Lanc stranded away from base for a significant period because of mechanical issues – remember that unlike in Britain, you can easily be a few days’ drive from base.

Might be worth asking one of our contributors from Atlantique.

I recall when that tanker went down off Wales about ten years back they operated the DC3 sprayers off a grass field near Havorfordwest.

Moggy

Whatever it comes down to, I think the CWH restrictions on operating their Lanc are ridiculous. As far as I’m concerned, the world has one and a half flying Lancasters!

Indeed (as Moggy also posted) these figures are for relatively small GA type aircraft. The problem is that there aren’t that many (if any) Lancaster sized types still around that are meant to operate from grass. Therefore as an operator you will need to write your own ops manual for these situations, or you need to dig out some very old charts (which probably don’t mean much now).

JDK pointed out that retardation on takeoff would not be very significant for a large aircraft, and I will admit to that, but on the other hand with a multi-engine aircraft you will also always need to look at an engine failure during TO situation. In that case you will need your brakes. Generally the heavier the aircraft the more crucial the lack of friction (or lesser friction) will be, either in an accelerate-stop scenario or during landing.

I remember watching about 4 B17s taking off from the grass at DX when they were filming memphisbelle

Have not seen Sally take off/land on grass for a number of years

Up to what aircraft weight?

Sounds to me those statements are talking about modern light aircraft..

I’m happy to be proven wrong, but a Tri-Pacer or even a Seneca isn’t a Lancaster;

Indeed the guidelines are almost certainly aimed at the up to 5700 kilo PPL limit, and you can assume they are pretty conservative.

A light Lancaster as opposed to one with full war load is a very different kettle of fish. If I were operating one at MAUW and beyond I’d still take the grass write-downs very seriously for take-off distance as the margin of thrust over weight/drag will be slim.

And for landing, I’d certainly be very generous. A heavy aircraft on wet grass is more likely to be a problem than a light one.

Moggy

Several of the instructional aircraft at Halton landed on the grass including the Comet 4 prototype in the hands of John Cunningham, circa 1959.

We’ve operated out of grass with 909 and our B-24 quite a bit. In fact we look forward to it because it is easy on tires and there is nothing like landing on grass…nothing. We flew Tondelayo out of Geneseo last year as well, another great time that posed no operational hazards.

Thanks for that Jim. Any operational differences you can share with us?

We’ve operated out of grass with 909 and our B-24 quite a bit. In fact we look forward to it because it is easy on tires and there is nothing like landing on grass…nothing. We flew Tondelayo out of Geneseo last year as well, another great time that posed no operational hazards.

Jim

Wern’t the early Vickers Valiant test flights flown from a grass runway at Wisley. 😮

Best wishes
Steve P

while trying to get back to airfield length requirements… I don’t know

Geneseo: Rwy 05/23, 4695 ft (grass)…

the Talichet ‘Memphis Belle’ operated there for this year’s show, and (personal POV) Yankee Air Force ‘Aluminum Overcast’ as well as the ‘Belle’ did as well in 2004… both without any degree of excessive runway use.

now, (someone please correct me if I’m wrong) any cancellation of the CWH Lanc from Geneseo this year would not be due to the airfield, but rather tech issues – again, as far as I have been led to believe, the CWH Lanc WILL NOT LAND anywhere other than Hamilton and (IIRC) will only display at shows no more than 2 hours flying time from Hamilton.

JJ

Thanks chaps. Where were you before I started guessing? 😀

CAA recommended write downs are…

Generally landing and take off runs are lengthened by 20-50% when operating off grass instead of hard surface runways. Indeed the retardation is stronger compared to tarmac, but this stops as soon as you start braking.

Up to what aircraft weight?

Sounds to me those statements are talking about modern light aircraft; so there’s enough significant factors of difference to a W.W.II tailwheel bomber type, even operated at the significantly lighter weights to wartime or in-service use.

I’m happy to be proven wrong, but a Tri-Pacer or even a Seneca isn’t a Lancaster; tailwheel vs nosewheel, tyre size and type and take-off and landing technique, involving aerodynamic effect and speed (‘three-pointing’ rather than ‘driving-on’ – crudely) would all have an influence as well as weight above all – and I can’t believe that grass will significantly retard a four engined bomber on take off.

As I say, I’m far from expert in this arena; but I’d like to know more.

See a small copy of the video here….. Click here to watch B-17-Sally-B-Landing-Bounce
Steve

Nicely recovered though.

Moggy

Re: “Sally B” Bounce

From memory, the Sally B bounce was a practice landing on a grass surface as they were due to land on a grass strip at another display within a couple of weeks. The bounce was about 30 feet high, and in slow motion, you could see the wingtips flex. I caught it on video, and you could here a loud gasp from the crowd around us. I imagine it was none to dull from inside the cockpit!

See a small copy of the video here….. Click here to watch B-17-Sally-B-Landing-Bounce

I fly a very large model of a B-17 ( see below ), and it handles much nicer on grass than tarmac, as does my P-47 and Vengeance. The grass allows a certain amount of sideways drift, where as on tarmac, the tyres bite hard and this can develop into a ground loop. Given the choice, I prefer a well maintained grass runway than concrete or tarmac.

Steve

CAA recommended write downs are

Landing

Short dry grass: tarmac distance +20%
Short wet grass: +30%
Long dry grass: +30%
Long wet grass: +40%

Take off

Short dry grass: tarmac distance +20%
Short wet grass: +25%
Long dry grass: +25%
Long wet grass: +30%

Moggy

I’m not a pilot or qualified, however in the absence of any comment on length so far (hem hem)

Let me add that bit then.

Generally landing and take off runs are lengthened by 20-50% when operating off grass instead of hard surface runways. Indeed the retardation is stronger compared to tarmac, but this stops as soon as you start braking. Then the friction coefficient is significantly lower than on a tarmac runway and therefore in total you need more room to stop (on takeoff the difference in length is less). Also grass runway conditions can vary a lot depending on soil, grass length, bumpiness, strength and obviously the weather, therefore you need to make allowance for these variables.

The answer remains yes, it can be done, but operating from paved runways provides more consistent results if I can put it this way. The exception is when you’ve got a significant crosswind, in that case grass can be more forgiving.

Sally B’s ‘bounce’ at DX was caused on that particular occasion by an upslope running up to the level of the the taxi way that leads to the runways end. It touched down at the bottom of the grass slope and the effect of running up hill launched it back into the air.
This had nothing to do with the surface being grass, it is just that its not as level as the hard runway.
Grass presents its biggest problem when its wet, becomes very slippery, demonstrated by Channel Airways in 1967 when two HS748’s, on the same day, were unable to stop at Portsmouth,s airport and ended up sliding through the boundery fence.

Question: How safe is it to land either Sally B or PA474 on a grass landing field? Also what kind of distances would be involved in both landing and taking off?

Certainly the Lancaster was designed to operate from all grass airfields – that’s why the damn huge tyres. I think the B-17 was likewise designed for grass field ops. The Lancaster was also considered for ‘accelerator’ launch (catapults to you and I) when fully loaded from bomber bases, but hard runways were introduced instead. The Stirling and Halifax were also expected to operate from grass.

I’m not a pilot or qualified, however in the absence of any comment on length so far (hem hem) I can see no reason a take off run would need to be any different from tarmac than grass. Landing should be essentially the same, with the variation being that heavy braking would be a bad idea on grass (but note that heavy braking is not nowadays normally required or desired in these machine’s normal ops). In theory a grass landing should be shorter than a tarmac one due to mild retardation by the grass and surface, but for aircraft of this size I’d imagine that’d be a negligible difference.

The real issue of off-grass operation would be the significantly increased risks of nasty surprises appearing from a grass runway; such as soft patches, collapsing drains and holes, ruts and so forth. Also, obviously, you’d want the ground to be hard and flat, so winter or post-rain operations not a good idea. With larger heavier aircraft such as these, you’d only find the soft patch when you hit it, I suspect, as there’d be nothing to find it of equivalent weight beforehand. You’d be trusting, in other words, to the preparation and maintenance of a very good grass runway by the owners. Places like Middle Wallop, where there is no alternative would be good; places where the grass is only used occasionally by light aircraft would be a risk.

That’s my logically deducing guess – anyone able to correct it? 😀

PA474 has operated off grass at Middle Wallop . Plenty of aircraft operate off grass with no distinct problems .

I was under the impression that since the “bounce” Mike mentions Sally B hasn’t and won’t be landing on grass again….