Gear fails - Put down on grass or tar?
Thread Starter
Join Date: Aug 2001
Location: BFS
Posts: 1,177
Likes: 0
Received 0 Likes
on
0 Posts
Gear fails - Put down on grass or tar?
If the gear were to fail, and I mean it stays retracted as opposed to unsafe warning, what surface is best to put down on?
I used to think grass without a doubt, and it was a stupid question. But someone has just told me that tarmac is the lesser of two evils and does less damage to the aircraft.
Am I being wound up? Anyone got any thoughts?
Cheers
SK
I used to think grass without a doubt, and it was a stupid question. But someone has just told me that tarmac is the lesser of two evils and does less damage to the aircraft.
Am I being wound up? Anyone got any thoughts?
Cheers
SK
I'd certainly say grass - to hell with damage to the aircraft, that's what insurance is for.
On grass you can expect less sparks, reduced impact peak loads, and better braking, three things I'd enjoy enormously under the circumstances.
G
On grass you can expect less sparks, reduced impact peak loads, and better braking, three things I'd enjoy enormously under the circumstances.
G
Join Date: May 2003
Location: Essex, UK
Posts: 616
Likes: 0
Received 0 Likes
on
0 Posts
Sparks won't be an issue unless fuel is pouring out of the wings.
Impact loads will be much less on a flat tarmac runway. Grass strips are not flat. With the belly of the aircraft sliding along the surface, the bumps of a grass field at 70kts are far more likely to break up the aircraft and the occupants.
I'll accept that there's less breaking on tarmac (than dry grass), but then tarmc runways tend to be quite long.
Given the choice of a gear up landing at Headcorn or Biggin, I know which I would choose.
Impact loads will be much less on a flat tarmac runway. Grass strips are not flat. With the belly of the aircraft sliding along the surface, the bumps of a grass field at 70kts are far more likely to break up the aircraft and the occupants.
I'll accept that there's less breaking on tarmac (than dry grass), but then tarmc runways tend to be quite long.
Given the choice of a gear up landing at Headcorn or Biggin, I know which I would choose.
Join Date: Mar 2000
Location: TL487591
Posts: 1,639
Likes: 0
Received 0 Likes
on
0 Posts
Every authority I have ever heard on this subject recommends a hard surface (concrete or tarmac). The unevenness of grass and the high likelihood of part of the airframe digging in and causing a flip, twist or breakup is the usual reason cited.
2D
2D
Join Date: Aug 2002
Location: Round and about
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
from my very limited experience - I'd be inclined to go for a hard surface, for the lower probability of digging in and flipping... along with bailing out rather than ditching for same reasons (yes I do fly with a chute most of the time!)
Our group has several experiences of wheels up on grass. Since we fly amphibs and the prop is behind the wing and above the hull we present a smooth surface. Ususally there is no damage, Just jack her up, drop the wheels and motor away.
The braking effect of grass is pretty good, far more so than regular brakes. When I was watching a wheels up the plane stopped in about 30 to 40 yards.
A few weeks ago one of our group put his plane down wheels up on tarmac. He realised as he 'sank' just what he had done and elected to power up. Took him about 2oo feet to get enough flying speed to drag her off and left a whacking great scar down the bottom of his fibreglass hull . Somewhat surprising that he got enough speed and elevator authority to get the nose up enough to lift off.
(By the way, Wheels down on water wrecks it every single time.)
Of course if you are wheels up in a regular plane walking away is the point, personally I don't have a clue but emotionally I'd choose the grass.
Are there any statistics on this?
The braking effect of grass is pretty good, far more so than regular brakes. When I was watching a wheels up the plane stopped in about 30 to 40 yards.
A few weeks ago one of our group put his plane down wheels up on tarmac. He realised as he 'sank' just what he had done and elected to power up. Took him about 2oo feet to get enough flying speed to drag her off and left a whacking great scar down the bottom of his fibreglass hull . Somewhat surprising that he got enough speed and elevator authority to get the nose up enough to lift off.
(By the way, Wheels down on water wrecks it every single time.)
Of course if you are wheels up in a regular plane walking away is the point, personally I don't have a clue but emotionally I'd choose the grass.
Are there any statistics on this?
Join Date: Mar 2000
Location: TL487591
Posts: 1,639
Likes: 0
Received 0 Likes
on
0 Posts
The issues associated with landing a floatplane are totally different to those associated with one which is not ordinarily designed to land without its wheels.
The kind of aircraft that most people fly here may well land with some wheels extended and a propeller or two, all of which will jab into the ground on landing giving rise to the risk of a violent decelleration and/or a flip.
Landing a pair of floats or a hull on grass is not really a fair comparison.
2D
The kind of aircraft that most people fly here may well land with some wheels extended and a propeller or two, all of which will jab into the ground on landing giving rise to the risk of a violent decelleration and/or a flip.
Landing a pair of floats or a hull on grass is not really a fair comparison.
2D
Join Date: Oct 2003
Location: UK
Posts: 510
Likes: 0
Received 0 Likes
on
0 Posts
Saw a twin do it at Elstree (onto tarmac) a few years ago and there was very little damage done. Horrible noise though.
Just out of interest, the actions for a uncertain gear position on a S61 is to put light contact on the wheels, and get someone to insert the safety pins into the undercarriage. Down and bolted. Seen it done too. The advantages of stopping then landing.
Just out of interest, the actions for a uncertain gear position on a S61 is to put light contact on the wheels, and get someone to insert the safety pins into the undercarriage. Down and bolted. Seen it done too. The advantages of stopping then landing.
Join Date: Jul 2004
Location: UK
Posts: 849
Likes: 0
Received 0 Likes
on
0 Posts
Fly to the nearest turf grower's fields and get the best of both worlds - the smooth prepared surface of tarmac, and the braking and fire retardent properties of grass. Then run like hell!
High Flying Bird
Join Date: Dec 2000
Location: Old Sarum ish
Posts: 2,297
Likes: 0
Received 0 Likes
on
0 Posts
John Farley wrote a fairly in depth article on the subject in Flyer mag a while back. Perhaps someone can remember which issue? He also went into what your best options were if the gear on only one side were to fail.
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,573
Received 422 Likes
on
222 Posts
Friend of mine once put down a Buccaneer, with total hydraulics failure, on the runway at St Mawgan.
No flaps, no gear, no airbrakes. Threshold speed of about 200 kts. The drop tanks, which were thought to be empty and kept on board to prevent the aircraft flipping over, wore through on the tarmac and the leaking fuel from them caused two major fireballs, the first way behind the aircraft, the second briefly engulfed it.
An (impressive) video was taken of the event. As the Bucc came to rest, the canopy opened within a second. Two crew jumped out and exited the camera frame, stage left, running like hell. Quite a while afterwards, the fire engines, which had been on the threshold and had to give chase up the runway, appeared wide stage right.
Don't think he would have done so well on the grass.......
No flaps, no gear, no airbrakes. Threshold speed of about 200 kts. The drop tanks, which were thought to be empty and kept on board to prevent the aircraft flipping over, wore through on the tarmac and the leaking fuel from them caused two major fireballs, the first way behind the aircraft, the second briefly engulfed it.
An (impressive) video was taken of the event. As the Bucc came to rest, the canopy opened within a second. Two crew jumped out and exited the camera frame, stage left, running like hell. Quite a while afterwards, the fire engines, which had been on the threshold and had to give chase up the runway, appeared wide stage right.
Don't think he would have done so well on the grass.......
Join Date: Nov 2003
Location: In a good pub (I wish!)
Posts: 250
Likes: 0
Received 0 Likes
on
0 Posts
Have done one so will throw in some thoughts. But what works for one incident may not work for another. Therefore think and plan.
Low wing aeroplane, decided to land on tarmac. The nose gear was half up/down and floating, decision made to land with mains up. The landing run was short, but deceleration not uncomfortable, flaps helped keep wings level.
Lower cowling, prop (not quite stationary), flaps and some lower fuselage skin damaged. No damage or stress to the two of us though, much to the disappointment of the local TV team!
Most importantly, take lots of time to think about where you're doing it, what RFF facilities they have, make sure ATC are fully aware of all circumstances, don't let them put you on an 'out of service' runway to limit their disruption, take the most into wind and benign runway/approach you can find. Plan your actions, eg who opens doors/canopies, who exits which side, who turns off fuel, electrics etc. Do your straps up TIGHT, think of where loose objects will end up, etc. Relax, carry out your plan.
Go for a beer afterwards. Most definitely do not accept any other form of counselling, because it's not needed/ will only make things worse!
Low wing aeroplane, decided to land on tarmac. The nose gear was half up/down and floating, decision made to land with mains up. The landing run was short, but deceleration not uncomfortable, flaps helped keep wings level.
Lower cowling, prop (not quite stationary), flaps and some lower fuselage skin damaged. No damage or stress to the two of us though, much to the disappointment of the local TV team!
Most importantly, take lots of time to think about where you're doing it, what RFF facilities they have, make sure ATC are fully aware of all circumstances, don't let them put you on an 'out of service' runway to limit their disruption, take the most into wind and benign runway/approach you can find. Plan your actions, eg who opens doors/canopies, who exits which side, who turns off fuel, electrics etc. Do your straps up TIGHT, think of where loose objects will end up, etc. Relax, carry out your plan.
Go for a beer afterwards. Most definitely do not accept any other form of counselling, because it's not needed/ will only make things worse!
Thread Starter
Join Date: Aug 2001
Location: BFS
Posts: 1,177
Likes: 0
Received 0 Likes
on
0 Posts
This has turned into a most informative thread - many thanks for the replies.
TD&H - Many thanks for reliving that one. I presume you were in a single(you mentioned prop in the singular)? Were it a twin would you still have elected for mains up?
It's something which to be honest I hadn't thought much about before. I just thought grass - soft - thats the one.
TD&H - Many thanks for reliving that one. I presume you were in a single(you mentioned prop in the singular)? Were it a twin would you still have elected for mains up?
It's something which to be honest I hadn't thought much about before. I just thought grass - soft - thats the one.
Join Date: Jun 2002
Location: Canada
Posts: 1,085
Likes: 0
Received 0 Likes
on
0 Posts
Happily, I have no personal experience of this issue. However, I have read various texts, safety bulletins, etc. suggesting that for most light aircraft, the question of grass vs. pavement is essentially academic: provided that the pilot keeps his cool and doesn't stall in or land extraordinarily 'hot', a 'gear-up' landing is almost always survivable, and usually results in modest or even minimal damage. I have several friends who have inadvertantly landed 'gear-up' on grass, and their experience bears this out.
I don't have extensive experience flying over water in a landplane, or flying over land in a seaplane. However, I do know that I have always felt much, much more comfortable in the latter situation. Properly handled, a floatplane can make an emergency landing almost anywhere (including many places a landplane couldn't handle), often with little or no damage to the floats. Again, I speak without personal experience (touch wood!), but this has been demonstrated many times and is supported by many authorities (Faure, Frey, Kurt, etc.).
The issues associated with landing a floatplane are totally different to those associated with one which is not ordinarily designed to land without its wheels
Join Date: Nov 2000
Location: Cambridge, England, EU
Posts: 3,443
Likes: 0
Received 1 Like
on
1 Post
Properly handled, a floatplane can make an emergency landing almost anywhere
Got used to flying around 100' above water - engine fails, just land. Found it more difficult to get used to flying around 100' above land - what do you do if the fan stops?
Instructor said, pointing at dirt track: "oh, we'd just put it down on that forest road, shouldn't do any real damage to the floats".