Bad landings... and how to avoid them
No phase of flight creates as much difficulty for pilots as landing. One only has to look at the incident reports to see the evidence: broken nose legs, damaged propellers, scraped wingtips and fuselages broken in two in aircraft that went over on their backs. These all occur with a dreary predictability.
In defence of pilots, no two landings are ever quite the same. Wind speed and direction, density altitude and runway surface friction all make a huge difference. Even experienced pilots occasionally land badly enough to damage an aircraft, so how can the tyro expect to manage? Rather than take the usual approach of detailing a good landing, our experts thought it might be more helpful to describe the top ten ways in which landings can go wrong.
1. WHEELBARROW LANDINGS
SYMPTOMS Nosewheel shimmy, weld fractures, bent tubes, ultimately a snapped noseleg
CAUSE Reaching the ground in a nose-down attitude because the aircraft had toomuch speed to touch down in any other way. The nosewheel touches before themainwheelsmaking the aircraft directionally unstable and very difficult to steer. However, assuming the throttle is closed the aeroplane will eventually slow to the point that the mainwheels touch. Until then, the noseleg is under considerable strain.
HOW YOU WILL KNOW If you have trouble steering a nosewheel aeroplane immediately after touchdown, you may be landing nosewheel-first.
CURE The aeroplane should bemaintained in level flight just above the surface until it is going slowly enough to be landed on themainwheels. If this means running out of runway, make a go around and approach at a lower speed (or find a longer runway).
2. BOUNCED LANDINGS (FAST)
SYMPTOMS Broken noseleg, damage to main legs
CAUSE The aeroplane is forced onto the runway before waiting for it to slow down. After several successive and increasingly violent bounces there is sufficient height for a stall and nosedrop so that the nosewheel hits first.
HOW YOU WILL KNOW You’ll be going faster than the landing speed when the wheels touch and you bounce.
CURE After flaring, hold the aeroplane just over the runway for longer before allowing the wheels to touch. If a bounce is followed by amore violent one, open up and go around.
3. BOUNCED LANDINGS (SLOW)
SYMPTOMS Damage to the main legs
CAUSE Misjudging height – imagining you’re just over the runway when in fact you’re several feet up.
HOW YOU WILL KNOW If you bounce after touching down at a low speed, it’s because you dropped on.
CURE Before takeoff, look around and memorise how the ground looks; this will help height judgement when you come to land. If you have poor depth perception, seek help from an instructor. One instructor’s tip from Tiger Moth days was to pull back the stick when you were low enough to see individual blades of grass.
4. CRABBED LANDINGS
SYMPTOMS Collapsed main legs, especially in aircraft with long legs mounted on the wings – these are particularly vulnerable to sideways loads.
CAUSE Usually a badly misjudged crosswind landing, but it is possible to touch down crabbed without a crosswind if, for instance, you normally land from the left seat and you find yourself landing from the right.
HOW YOU WILL KNOW One wing lifting as the wheels touch, combined with a screech fromthe tyres as they skid sideways. The aircraft will yaw and you will feel it lurch to one side.
CURE The pilot needs to develop awareness of sideways drift and how to compensate for sitting off-centre. Often the cure is simply to be aware of the problem and look out for it, but if necessary advanced training with an instructor should be sought.
5. HEAVY LANDINGS
SYMPTOMS Damage to the undercarriage, its mountings and possibly to the airframe. A heavy landing has been known to damage the wing spar and fracture the longerons in the fuselage.
CAUSE Many aircraft are designed so that full aft elevator is too weak to cause a stall and nose drop (unless combined with a blast of power). If allowed to get too slow during the approach, these aircraft instead develop a formidable sink rate. The pilot is fooled by the aircraft’s relatively level attitude and by the time he realises that the ground is rushing up, it’s too late. Since the aircraft hits the ground in a nose-high attitude, it’s usually the main legs that take the strain.
HOW YOU WILL KNOW You’ll know – the sensation of a heavy landing is unmistakable. The ground seems to rise up and strike the aeroplane.
CURE Closely monitor airspeed throughout the approach. If the aircraft falls below ‘over the hedge’ speed as you cross the threshold, open the throttle. Avoid a panicky pull back on the stick if both low and slow. If in doubt, apply full throttle and go around.
6. COLLISION LANDINGS
SYMPTOMS An expensive bill from the airport manager for a new PAPI or runway marker and damage to spats, brakes and wheel parts
CAUSE Drifting off track and landing in the wrong place. Runways at some airports are flanked by landing lights.
HOW YOU WILL KNOW The aircraft will lurch to one side and one wing will rise and drop again.
CURE If you have allowed the aircraft to drift off track, don’t press on, but abandon the approach and make a go around.
7. GROUNDLOOP LANDINGS
SYMPTOMS Scraped wingtip and there will probably be hidden damage to the airframe and particularly the undercarriage mountings.
CAUSE A groundloop (mainly occurring in taildraggers) is an uncontrolled acute change of direction – usually the aircraft swings round through 180 degrees. This puts a big sideways strain on the wheels and can lose a tyre or collapse the legs.
HOW YOU WILL KNOW The aircraft will autorotate to one side, the yaw rapidly gathering speed. In a flash you are a helpless passenger. If you have time to react with rudder and differential brake, you will find them helpless to stop the rotation. A groundloop can happen at any speed above a slow walking pace. The faster the speed, the greater the damage, but even at fast taxi, a groundloop can do considerable harm, even though it may feel quite gentle from the cockpit.
CURE Rigid concentration on keeping the aircraft running in a straight line. Once the aircraft begins to turn, there is a moment when differential brake plus opposite rudder and in some aircraft a burst of throttle will be powerful enough to stop it. If you lose that opportunity, a groundloop is inevitable.
8. FAST LANDINGS
SYMPTOMS Tyre creep (evidenced by paint lines out of alignment), flat spot on tyres, rubber streaks on the runway. The tyresmay be pronounced unserviceable and have to be replaced, which is expensive.
CAUSE It is possible to land many aircraft on a smooth surfacewithout bouncing or other problems, but going much too fast. The pilot is then forced to brake relatively fiercely in order to stop in time.
HOW YOU WILL KNOW If you have to brake in a panic and hear sustained squealing from the tyres.
CURE Go around and make a slower approach next time or divert to an airport with a longer runway. Either way, don’t allow the aircraft to touch down until it has reached the recommended landing speed.
9. BUCKET LANDINGS
SYMPTOMS Broken leafsprings in the tailwheelmount.
CAUSE Landing nose-high with the tailwheel touching down first. This is followed by fore-and-aft bucketing: the aircraft bouncing from mainwheels to tailwheel and back with increasing violence.
HOW YOU WILL KNOW The bucketing gives the game away. It can become sufficiently violent to cause a prop strike.
CURE Memorise the ground attitude before takeoff and don’t allow the nose to get any higher than that when you land.
10. ‘UNDECIDED’ LANDINGS
SYMPTOMS A hole in the boundary hedge or wrecked aircraft at the far end of the runway.
CAUSE Much too late, the pilot decides he hasn’t room to stop and makes a panicky decision to go around. Either the aeroplane fails to leave the ground and ploughs into obstacles or it staggers into the air and stalls.
HOW YOU WILL KNOW Pilots to whom this is going to happen generally get several warnings with panicky, late go arounds that they only just get away with. Dithering about go arounds is often linked to fading confidence.
CURE If you realise you are becoming indecisive and unsure about your landing technique, don’t bluff it out – instead ask an instructor for some re-training.