do you like it hard or soft.........
Thread Starter
Joined: Jul 2002
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From: abroad
do you like it hard or soft.........
the runway that is 
Having completed my entire PPL on hard surfaces, (from 2500ft to 12,000ft
), what are the main differences I'm likely to encounter on my first grass strip flight?
I seem to remember reading that take off runs can be longer/landing runs shorter or is it vice versa? Obviously grass length, and wet or dry are other factors.
Any knowledge to share?
Having completed my entire PPL on hard surfaces, (from 2500ft to 12,000ft
), what are the main differences I'm likely to encounter on my first grass strip flight?I seem to remember reading that take off runs can be longer/landing runs shorter or is it vice versa? Obviously grass length, and wet or dry are other factors.
Any knowledge to share?
Joined: Apr 2002
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From: Norfolk
You have it about right. There is additional roll resistance on grass which will shortern landing and lengthen take off particularly if the grass is longer than bowling green cut. Other things to look out for are lengthier landing runs on wet grass if normal procedure is to brake hard. Wet grass can make a great skating rink. The other, and often most noticeable is that grass strips are often far less even than hard runways and you can expect to be shaken and stirred a little.
Not a grass vs hard issue but often grass strips will be shorter than hard runways, also ofetn less well marked so this can create very different perspectives than (say) a hard runway at an international airport.
I would only advise avoidance in the case of an aircraft with take off and landing performance which is marginal on the length of runway in question or the aircraft has limited prop clearance. Otherwise caution is adequate.
Not a grass vs hard issue but often grass strips will be shorter than hard runways, also ofetn less well marked so this can create very different perspectives than (say) a hard runway at an international airport.
I would only advise avoidance in the case of an aircraft with take off and landing performance which is marginal on the length of runway in question or the aircraft has limited prop clearance. Otherwise caution is adequate.
Joined: Jun 2002
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From: New South Wales
The thing I remember most from my first grass ops was the NOISE, tarmac tends to be nice & smooth but grass bounces the gear about and makes for a much noisier run down the runway.
QDM
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From: Oop North, UK
[Nah, that's only in spamcans]
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From: Paros, Greece
Each bumpy grass runway has it's own 'personality'. If you haven't landed on a particular strip before, be prepared to be bounced into the air at around stall speed, either on landing or takeoff. Not so much of a problem if you're expecting it, but can be on a new runway. Just keep the weight off the nosewheel as much as possible (if you have one) - the 'oildrum' sound in a Pa28 is a dead give away that you need more back pressure.
I'm learning on grass and have problems with perspective and height judgement when landing at large 'international airports'. Guess it's just down to experience.
I'm learning on grass and have problems with perspective and height judgement when landing at large 'international airports'. Guess it's just down to experience.
PPruNaholic!
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From: Buckinghamshire
I am always surprised when I read of people who trained on grass being a bit anxious about landing on hard surfaces. Like you, I trained on hard - but I like both (steady!)...
I was a bit taken aback with my first solo grass landing, which happened to be at Goodwood on 06 on my QXC. This runway is plenty long - at least as long as the hard surface I had departed from at my training airfield Wycombe - but was slightly damp (morning dew?) and I was very surprised at how slippery it was... this became apparent when I started braking! Easy to deal with, just backed off the brakes a bit, but made my heart skip!
Be sure to be familiar with all the relevant calculations as shown in the Saftey Sense leaflet, and even if you don't think its necessary I'd recommend that you actually do the calculations with your POH in hand - at least the first few times you use a given grass runway. You'll be surprised at how all the various fudge factors add-up! For instance, I know that if I am in our club's Dakota (heavier than a regular Warrior) then I can't accept a landing on Sywell's 15 (unless it happens to have a seriously stonking headwind!). So whenever I go there in that aircraft, I make note of this and if they can't give me another runway (if in XW limits) I go elsewhere.
I really enjoy some bumpy grass strips - e.g. White Waltham's 25 - you don't get to decide when to become airborne, the runway kinda decides for you
The relevant Safety Sense leaflet 7B is here and similar information is in AIC 67/2002 (Pink 36)
(Reading Simon W's post below has reminded me that we have grass at Wycombe! But I had never had to land on it solo before the experience mentioned at Goodwood...)
I was a bit taken aback with my first solo grass landing, which happened to be at Goodwood on 06 on my QXC. This runway is plenty long - at least as long as the hard surface I had departed from at my training airfield Wycombe - but was slightly damp (morning dew?) and I was very surprised at how slippery it was... this became apparent when I started braking! Easy to deal with, just backed off the brakes a bit, but made my heart skip!
Be sure to be familiar with all the relevant calculations as shown in the Saftey Sense leaflet, and even if you don't think its necessary I'd recommend that you actually do the calculations with your POH in hand - at least the first few times you use a given grass runway. You'll be surprised at how all the various fudge factors add-up! For instance, I know that if I am in our club's Dakota (heavier than a regular Warrior) then I can't accept a landing on Sywell's 15 (unless it happens to have a seriously stonking headwind!). So whenever I go there in that aircraft, I make note of this and if they can't give me another runway (if in XW limits) I go elsewhere.
I really enjoy some bumpy grass strips - e.g. White Waltham's 25 - you don't get to decide when to become airborne, the runway kinda decides for you
The relevant Safety Sense leaflet 7B is here and similar information is in AIC 67/2002 (Pink 36)
(Reading Simon W's post below has reminded me that we have grass at Wycombe! But I had never had to land on it solo before the experience mentioned at Goodwood...)
Last edited by Aussie Andy; 16th October 2002 at 13:20.
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From: London
Did a bit of learning on both and have used a bit of both since...grass tends to flatter my landings as its usually a bit softer than hard, but you do have to be very circumspect about potential prop-strikes in tricycle aircraft , its v. important to keep the weight off the nosewheel as much as possible. Take offs, conversely, can be a bit of a random affair as small bumps and lumps can have you skipping down the runway before the aircraft is really ready to be airborne.
Grass can also be surprisingly draggy for take off and slippery for landing, take a good look at the relevant Safety Sense leaflet. I also seem to recall the Thom manuals cover this area pretty well, in particular the performance factors you need to apply.
Grass can also be surprisingly draggy for take off and slippery for landing, take a good look at the relevant Safety Sense leaflet. I also seem to recall the Thom manuals cover this area pretty well, in particular the performance factors you need to apply.
Joined: Apr 2001
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From: Hertfordshire, England
As with Aussie Andy my training airfield is also Wycombe. My first landing on a grass runway was actually when doing circuits at Wycombe when I was instructed to setup for an approach on 25L (grass) instead of 25R (hard). The main thing that shocked me was how much bumpier it is. Doing a take off it feels like the plane is going to fall apart. I think with grass strips you've just gotta be extra extra light on the nosewheel.
Joined: Sep 2002
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From: Midlands
grass strips
A lot of heavily used grass strips tend to be really rough despite efforts to smooth/ drain them.
I have landed on plenty of strips in 26 years of flying and the roughest ever - ever - is the one at Woburn. I feel that it is the ideal 'what would it be like to force land in a ploughed field' simulator.
Mind you - I did chicken out at Lundy a few years back - a bit better now I believe.
I actually prefer grass. Despite your tyres and brakes lasting longer, grass runways are preferable for old taildraggers.
Don't get the drift off quite right in a spammer and it just costs you rubber. However, in some tailwheel types it can spoil your whole day.
A groundloop on grass is usually a red face only. Do it on tarmac and the risk of damage increases.
Check out Weybourne nr. Cromer. I went there last week in the Robin. Slopes/ rising ground/ do you take a tailwind component and go downhill? All decisions that will not be necessary on tarmac. I dont know of any that aren't flat or thereabouts.
(Weybourne has an interesting tank/ Aviation museum - they also used to fire off DH Queen Bees there in the War. Nice restaurant but now closed until the spring. Strip should be OK to use though..)
All part of the learning process.
Get some in!
BB
I have landed on plenty of strips in 26 years of flying and the roughest ever - ever - is the one at Woburn. I feel that it is the ideal 'what would it be like to force land in a ploughed field' simulator.
Mind you - I did chicken out at Lundy a few years back - a bit better now I believe.
I actually prefer grass. Despite your tyres and brakes lasting longer, grass runways are preferable for old taildraggers.
Don't get the drift off quite right in a spammer and it just costs you rubber. However, in some tailwheel types it can spoil your whole day.
A groundloop on grass is usually a red face only. Do it on tarmac and the risk of damage increases.
Check out Weybourne nr. Cromer. I went there last week in the Robin. Slopes/ rising ground/ do you take a tailwind component and go downhill? All decisions that will not be necessary on tarmac. I dont know of any that aren't flat or thereabouts.
(Weybourne has an interesting tank/ Aviation museum - they also used to fire off DH Queen Bees there in the War. Nice restaurant but now closed until the spring. Strip should be OK to use though..)
All part of the learning process.
Get some in!
BB
Joined: Jul 2001
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From: N.E. Derbyshire, UK
I learnt on hard (6000ft) runways but now fly out of Netherthorpe with the shortest (licenced) grass runways in the UK.
Apart from being bumpy, the main difference I find is the actual take off. On a hard runway you make a (gentle but positive) rotation by pulling back on the yoke at the appropriate speed (say 55kts in a C150 without flap).
On a grass strip, common practice is to use the soft field technique, i.e. pull back slightly on the yoke to lift the nosewheel clear of the grass to reduce drag. This tends to result in the aircraft flying itself off the runway, and so care is needed to level off when clear of the grass to allow the airspeed to increase - otherwise a significant risk of stalling may occur if it is gusty.
Combine this with the bumps, and it seems as though you actually do about 10 take-offs and 9 landings in every take-off run....
Apart from being bumpy, the main difference I find is the actual take off. On a hard runway you make a (gentle but positive) rotation by pulling back on the yoke at the appropriate speed (say 55kts in a C150 without flap).
On a grass strip, common practice is to use the soft field technique, i.e. pull back slightly on the yoke to lift the nosewheel clear of the grass to reduce drag. This tends to result in the aircraft flying itself off the runway, and so care is needed to level off when clear of the grass to allow the airspeed to increase - otherwise a significant risk of stalling may occur if it is gusty.
Combine this with the bumps, and it seems as though you actually do about 10 take-offs and 9 landings in every take-off run....
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From: europe
I seem to remember a technique where you jumped the flaps, that is at a speed just below normal take off you dropped two stages of flap and hauled the airplane off the ground, thus shortening the ground drag of a grass strip.
Is this still a valid technique?
Is this still a valid technique?
Thread Starter
Joined: Jul 2002
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From: abroad
Many thanks one and all, it never ceases to amaze me how much information this forum can provide
I think there's probably enough experience here to start an online groundschool, you should start charging fees
I think there's probably enough experience here to start an online groundschool, you should start charging fees
Joined: Sep 2002
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From: Midlands
Jumping the flaps
Dear Bluskis,
THere has to be some aerodynamic advantage in this, ie accelerate without the drag of the flaps and then dropping them at the critical speed. However, I suspect that it is something for experienced bush pilots in really tight strips or nutters - sounds lke a recipe for a smoking hole. I can't imagine anyone teaching it.
Maybe glider tug pilots practise this when snatching a glider out of a small field? I can understand it then perhaps.
They are generally very experienced and really current.
Bottie
THere has to be some aerodynamic advantage in this, ie accelerate without the drag of the flaps and then dropping them at the critical speed. However, I suspect that it is something for experienced bush pilots in really tight strips or nutters - sounds lke a recipe for a smoking hole. I can't imagine anyone teaching it.
Maybe glider tug pilots practise this when snatching a glider out of a small field? I can understand it then perhaps.
They are generally very experienced and really current.
Bottie
Joined: Jul 2001
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From: N.E. Derbyshire, UK
Bottie - agree with you - sounds little like a recipe for disaster to me. I can see the principle of gaining groundspeed & airspeed more quickly, but even to drop 10 degrees of flap would suddenly create so much additional drag I'm not sure what the resultant aerodynamics would be like. Add to that any crosswind element and.....
It was certainly not something my instructors suggested to me. I would suggest that if you can't get airborne within the available TODA using the airframe recommended short-take off technique, then you're either too heavy, too high or too hot. Or you picked a bummer landing at that airfield in the first place....
It was certainly not something my instructors suggested to me. I would suggest that if you can't get airborne within the available TODA using the airframe recommended short-take off technique, then you're either too heavy, too high or too hot. Or you picked a bummer landing at that airfield in the first place....
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From: europe
Bottie
Thanks for reminding me of the aerodynamic reasoning behind this technique.
I was taught it back in the 1960's and used it on Cherokees.
I wouldn't try it today without a refresher with an instructor, and that means I will probably never use it again as my SEP has lapsed leaving me just with an MEP.
Thanks for reminding me of the aerodynamic reasoning behind this technique.
I was taught it back in the 1960's and used it on Cherokees.
I wouldn't try it today without a refresher with an instructor, and that means I will probably never use it again as my SEP has lapsed leaving me just with an MEP.
Joined: Jan 2002
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From: Paros, Greece
Bluskis, I asked the same question of my instructor once and when she'd recovered from the shock explained:
What if when you pull the handle nothing happens?
Or the flaps come down asymetrically?
Or you miss the level and have to look down inside the a/c
Or you accidently pull the gear retract (in a retractable, obviously)
Mind you, {anorak on} it works well in FS2000 {anorak off}
big.al - If I'm ever allowed to fly into Netherthorpe, I'd be very tempted by this technique!
PS. Or what if you're in a C150 - the flaps would just be extended by the time you turned downwind
What if when you pull the handle nothing happens?
Or the flaps come down asymetrically?
Or you miss the level and have to look down inside the a/c
Or you accidently pull the gear retract (in a retractable, obviously)
Mind you, {anorak on} it works well in FS2000 {anorak off}
big.al - If I'm ever allowed to fly into Netherthorpe, I'd be very tempted by this technique!
PS. Or what if you're in a C150 - the flaps would just be extended by the time you turned downwind
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From: N.E. Derbyshire, UK
Knobby - if you're from Derbyshire, where do you fly out of?
Quote: "Or what if you're in a C150 - the flaps would just be extended by the time you turned downwind"...
... try that at Netherthorpe and you'll be across the road and into the farm by the time the flaps are deployed, or if taking off on 06 you'll probably be on the crown-green with the bowlers at the next village, and they don't take kindly to people using their green without having booked first...
Quote: "Or what if you're in a C150 - the flaps would just be extended by the time you turned downwind"...
... try that at Netherthorpe and you'll be across the road and into the farm by the time the flaps are deployed, or if taking off on 06 you'll probably be on the crown-green with the bowlers at the next village, and they don't take kindly to people using their green without having booked first...
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From: europe
Knobbygb
You have checked flap integrity and operation as part of preflights, so assemetric deployment is unlikely.
The flaps were mechanically operated not electrically operated, it was a low wing aircraft not a high wing aircraft
The big thing I remember in the Cherokee was to make sure you haul on two stages, not three, but it had a big handle and definate clicks as I remember, and it was fixed u/c so no confusion there.
However as I previously said it was a long time ago and I personally would want to go through the manouvre with someone current on the procedure before trying it again.
My experience of rough and unlicenced strips is such that I give them a miss.
You have checked flap integrity and operation as part of preflights, so assemetric deployment is unlikely.
The flaps were mechanically operated not electrically operated, it was a low wing aircraft not a high wing aircraft
The big thing I remember in the Cherokee was to make sure you haul on two stages, not three, but it had a big handle and definate clicks as I remember, and it was fixed u/c so no confusion there.
However as I previously said it was a long time ago and I personally would want to go through the manouvre with someone current on the procedure before trying it again.
My experience of rough and unlicenced strips is such that I give them a miss.