Crosswind Landings and A Surprise 35-knot Headwind

WEATHER

Malaysia is considered a mild climate country as there is no extreme temperature. Most of the time it lies between 28C to 33C in the afternoon with a drop of about 3C in the early morning in the lowlands where most people live. Similarly winds in Malaysia rarely reach above 20 knots, so pilots generally have little experience in handling strong crosswinds during landing. For mild crosswinds, some training in crabbing and sideslipping techniques for landing is usually made mandatory  .

LANDING TECHNIQUES

In the former, the nose of the aircraft is deliberately pointed at an angle into the wind to counteract the otherwise sideways drift leewards. So, instead of pointing straight towards the runway, the aircraft is "crabbed" towards it. Moments before the wheels touch the runway, the nose is swung back to align with the centreline on the runway so that the wheels will roll forward as normal and not be dragged sideways causing the aircraft to skip or even topple on its side.

The latter technique involves lowering the windward wing while keeping the nose pointed straight towards the runway. The resulting sideways lift of the wings will counteract the otherwise leeward drift. The disadvantage of this technique is that the plane will sink faster towards the ground as the wings' vertical lift is now reduced by its sideways component which was created by banking the wings windward. The advantage of this technique, however, is that one can come in higher than normal and still be able to land on the threshold (a spot just after the edge of the runway marked with white stripes nicknamed "piano keys").

I have occasionally used both techniques over the course of my flying years but there was one instance when I could not use them and had to quickly devise my own technique. This was because this time the wind was coming from the front at about a 15-degree tangence  but the wind speed was 35 knots!

THUNDERSTORM

Here is how it all started. It was a bright day and I thought I would put in a half-hour to one-hour flight within the training area called R218. This area is a reasonably wide corridor that lies roughly between Kajang (2 minutes away from Sempang, our home airfield) and Semenyih. It has an upper limit of 2,500 feet and is used for training purposes as well as a transit lane for flights to and from the south. I scanned the sky before preflighting the aircraft and noted some rain clouds in the distance over Subang 6 miles away. They did not look threatening at all.

After obtaining Air Traffic Control (ATC) clearances, I took off and practised some manoeuvres within the training area. After about 30 minutes, ATC radioed me that the weather was closing in on the airfield and I was advised to return to base. As I neared Bukit Besi overlooking the airfield, there was a huge dark cloud hanging right on top of the runway and ATC advised that I was cleared to land with the surface wind indicating 200 degrees at 35 knots. Never had I heard such a strong wind from any ATC before but I believed it because that huge cumulonimbus cloud had a base at only around 2,000 feet. I could see the trees around the airfield swaying wildly. ATC then came on with a polite question "Do you need any assistance?" which they always say when they think a pilot or an aircraft might be in trouble.

LANDING

I assessed the situation as I turned right to join downwind at 1,000 feet for a left-handed pattern for Runway 22. With the wind almost head on at 35 knots and my normal final approach speed at 60 knots, my airspeed would show 95 knots when I touch down but the ground speed would be just 60 knots. This could not be the usual landing using flaps anymore as the flap limiting speed is only 80 knots and an airspeed of 95 knots might just rip them off. A flapless approach at an airspeed of 105 knots (normal flapless approach is at 70 knots) would just do the job, so I told ATC "Final, no flaps" which he acknowledged. By that time the sky had opened up and heavy rain was pouring on the aircraft and the airfield. It was a totally new experience for me to see the Airspeed Indicator (ASI) showing more than 100 knots as I touched down smoothly without flaps. All my previous no-flap landings over the years had not more than 70 knots or thereabouts on the ASI, so it was hard to believe that I was doing what I did as I descended the last 300 feet onto the runway and rolled out. The arithmetic has once again been proven - 105 knots on the ASI with a 35-knot headwind is equal to a 70-knot landing.

PARKING IN THE WATER

I thanked the ATC as I taxied into the ramp and stopped the aircraft. Another problem had however just cropped up. There was no umbrella in the plane and there was no way I could run into the hangar without getting drenched to the skin. So I waited it out in the cockpit for about half an hour before the rain finally eased. By then the aircraft's wheels were totally submerged in water. I removed my shoes and socks, rolled up my pant legs and waded to the hangar. So much for the Malaysian weather, a short flight in a bright sky can turn into a freaking thunderstorm and flooding in less than 45 minutes.

Mysterious Incident In Good Weather

One incident that occurred while I was flying remains a mystery to me until today. It was during a flight home from Tioman Island to KL (Tioman being the island I fly to most often for reasons the reader will ultimately find out as he or she continues to read my blogs).

The weather was simply beautiful at that time which was around six in the evening and we were flying at 2,500 feet. When we were roughly abeam Genting Highlands on our right I saw the RPM Indicator suddenly reading 2,450 rpm (which for the C172 means that the propeller was turning at that speed). Normal cruise setting is usually 2,200 to 2,300 rpm during level flight.

I automatically assumed that the plane was diving because only when a plane is diving will the RPM increase by itself ( a result of gravity pulling the plane down and increasing its speed). So I pulled the control column back to maintain level flight and reduced the power by pulling the throttle lever back towards me. I managed to hold the nose level by pulling back hard on the control column and holding it there but the throttle lever was forcefully pulling itself back into the instrument panel. I pulled the throttle lever back again with all my strength but the engine responded by again pulling it back into the panel. The altimeter was showing that we were descending at about 100 feet per minute with my nose level which is not too alarming.

This tug of war between myself and the engine continued a few times and I was fearful that the throttle cable behind the panel would snap because the force that was pulling it back in was really great. If it had snapped, the engine would turn at maximum speed and, if prolonged, damage itself. Worse still I would then lose control of the delinquent aircraft. I looked at the Airspeed Indicator to see if the speed of the aircraft had increased correspondingly and it was up to about 100 knots, which is on the fast side but not yet in the danger zone. Probably by pulling hard on the control column I had managed to keep the plane's speed within limits (high speed can weaken the aircraft's structure).

There was nothing else I could do other than pray that the situation would not worsen. I had three passengers with me who had never flown in a small plane before this and I could not let them see that I was in trouble. I decided to descend a bit lower as we would soon be required by Air Traffic Control (ATC) to maintain 1,500 feet as we enter the KL control zone. This enabled me to reduce the pressure I was putting on the control column and I also would be able to test if the engine RPM would increase further as we descended. Just as suddenly as it started, the engine RPM normalised and became controllable again. I could pull the throttle lever back and forth without forcing it. Pressure on the control column was also relieved.

After changing the radio frequency from Lumpur Information's to Sempang Tower's, I was mighty glad to be able to speak to my home airport controllers again. What a satisfying feeling it was to land the aircraft as normal and without my passengers noticing any difference. It could have been a different story though.

I asked around but none of the pilots I spoke to had experienced it the way I did. I asked the engineer to check the plane thoroughly after the flight and he found nothing out of the normal. My guess is that I had entered an area of clear air turbulence (CAT) where there was a strong downdraft coming from the front of the aircraft. This would have increased both my propeller RPM and the airspeed while causing the plane to descend. However I still cannot believe the really strong force that was pulling the throttle lever back into the panel.

Does Flying Kill?

The answer is a definite yes. However there are precautions one can take to lessen the probability of that happening.

A. LOSS OF CONTROL

If the pilot is caught in a situation where he has lost control of the plane due to:

a) jammed or severed control links or

b) damaged or detached control surfaces

c) incapacitation

d) his seat has slipped and moved away from the controls for some reason and he is not able to reach them again

the plane will likely go down with the weight of the engine pulling the rest of the plane with it. Even if the engine is running perfectly, the inability of the pilot to maintain straight and level flight will mean gravity will take over and the plane will dive towards the ground with an increase in the rate of descent as it drops in altitude.

B. ENGINE FAILURE

If the plane is in perfect condition but all the engines fail, his survival depends on:

a) how near he is to a safe landing site and his altitude. He should not be too low as he needs to glide over that distance to the selected landing site or until he can make a midair restart.

Two famous incidents where the planes lost all power but managed to land with no loss of life are the US Airways Flight 1549 which landed on the Hudson River and British Airways Flight 38 which landed short of Heathrow Airport's runway.

b) If the plane has more than one engine and one fails, he is still able to fly to the nearest airport and land safely on the other engine(s) using asymmetric flying techniques.

C. RESPECT THE WEATHER


Many aircraft incidents (other than from pilot error) are due to weather:


a) a violent storm in a rain cloud may rip the aircraft apart

b) hailstones may damage parts of an aircraft such as the propellor or control surfaces

c) ice may build up in the engine and block air or fuel from reaching it

d) ice may also accumulate on the wings altering their shape and making them lose their aerodynamic lift as well as increasing drag

e) visibility in a cloud may be so poor that the pilot cannot see an obstacle ahead. A billowing cloud may be nice to look at from afar and on a bright and sunny day but it is a totally different scenario from inside it.

Very often a pilot begins his flight in good weather but later encounters bad weather on his route. While most airliners can fly higher to avoid weather, small aircraft may not be able to do so and the pilot must decide whether to continue, divert to a safer airport or even return to his airport of origin.His decision can be a matter of life or death.

I have been in situations where even turning back has to be ruled out because clouds have begun to move in behind me. One then has to fly lower so as to be below the cloud base. This situation often happens in hilly areas because the moist winds move up the slopes and cool as they rise. The moisture then turns into clouds. When faced with this situation,a pilot has to "scud run" meaning he has to weave along the bottom of the valleys. He just prays that there is no dead end or a huge obstacle at the next turn.

D. SKILL AND EXPERIENCE

A pilot needs to be skilled to survive. Besides being meticulously trained, he needs the experience to enable him to foresee problems before they crop up, to read the weather, to understand the locality in which he flies, to know the capabilities and limitations of his aircraft and to remain calm and disciplined when faced with an emergency. An experienced pilot can tell when there is something not right with his aircraft by the feel of the control column, the attitude (position in relation to the horizon), the sound and vibration of the engine, etc.

There are certain emergency situations that a pilot can practice for. These include engine failure, fire during flight or on the ground, wheel brake failure, landing gear failure, electrical failure and other system malfunctions. The steps and procedures to overcome these must be followed precisely and repeatedly until they become second nature to him. When an actual emergency arises, he will automatically carry out the procedure on reflex as there usualy is insufficient time to think anymore.

E. PREPARATION

All flights begin with preparation. The route must be drawn up with the required waypoints, altitudes, speeds and possible diversions (alternate airports) in case of weather changes or emergencies. Even the alternate airports have to be screened to ensure that they have the required runway length and facilities for refueling, etc. Weather forecasts for the length of the route have to be studied and the route modified accordingly.

The pilot himself must be in good condition with sufficient rest and food and appropriately clothed. If flying over water, life jackets must be carried. Survival equipment and first aid kit must also be on board. The aircraft must be in good flying condition with sufficient fuel including reserve in the tanks. The fuel must be checked for possible contamination.

A series of checks must be carried out before, during and after each flight. Comprehensive check lists are used to avoid missing anything. Missing a small check on the ground can mean a big problem in the air. If a fuel cap or baggage door is not secure, it may open in flight and there will be no volunteer to crawl out of the plane and re-secure it at a thousand feet above the ground. Similarly if one miscalculates the fuel quantity required, the aircraft may have to make an emergency landing on top of a tree.

F. A LESSON LEARNT

I had a not so funny experience once when flying with another pilot. It was a flight from KL to Tioman Island and back. I prepared the navlog (navigation log detailing the waypoints, compass headings, altitudes, leg times, etc.) for my outbound flight to Tioman and since the other pilot was to fly the return leg, I assumed that he had done the same for that leg. When we took off to return to KL, he asked me for the heading to fly. I mentally reversed all the compass directions from my navlog and gave him the first heading to follow. I had however absent mindedly given him the reverse of the first heading on my navlog, which was the KL-Kajang leg of 150 degrees, so reversing it resulted in 330 degrees.

It normally takes 34 minutes over the sea in a westerly direction to reach the next waypoint of Kuala Rompin. After thirty minutes out from Tioman we saw the coast some distance away to our left and sensed that something was not right. We nevertheless continued towards the coast and found ouselves over Kuantan,which is 100km to the north of where we were supposed to be. We had wasted some fuel by taking that diagonal track to the coast and now we had to take a longer route than planned to reach KL.

At that time the refueling facility at our home base in KL was unserviceable and all pilots were required to refuel at Subang airport nearby before returning, so we tracked for Subang. All this meant that we had to fly longer than our planned flight and our fuel was running low. At one point the engine sputtered for a number of seconds but then resumed running. We prayed that we really could reach Subang. This we miraculously did.

When the refueler looked into our tanks they were shocked to find no fuel inside. A failure to prepare a simple navlog could have spelt disaster for us. There were no GPSs those days (or they were too expensive then). Today, that incident would not have happened as a GPS will tell you exactly which heading to follow.

Perhaps another lesson learned from this episode is to always double check the information given you by another crew member. Even if one is told "the external checks have been completed", "we have 40 gallons of fuel", or "the minimum safety altitude is 2,500 feet", etc., it is wise to take a second independent look. In the above case, Kuala Rompin is directly to the west of Tioman, so a heading of 330 degrees should have made us question it. Sometimes when we are busy doing something else or in a hurry, simple things like that are missed.

DISCIPLINE

This is probably the greatest life saver to a pilot. Without it, a pilot's life may be short. As they say, there are no old bold pilots. As the captain of an aircraft, he must make decisions all the time concerning the safety of his aircraft and passengers. Should he refuse a flight if the weather is adverse or if a certain component of an aircraft is not functioning? Can he take a certain amount of risk and continue his flight? An inoperative fuel gauge may be acceptable if the tanks have been checked and found to be full but what if a leak develops during flight? He will have no way to check if there is still sufficient fuel on board. Similarly, should he carry more cargo and passengers and reduce his reserve fuel or should he upload more fuel than necessary to cater for diversions due to weather, wind conditions, traffic congestions, etc.? A disciplined pilot will take the minimum risk in all these matters but sometimes he has to relent when his employer insists on pushing the limits.

CONCLUSION

Yes, flying can kill but an aviator must fly (for whatever reason). As long as he is disciplined, puts in as much practice as possible and consciously carries out the recommended procedures, he probably can avoid getting into difficulties. As he logs more and more flying hours, he can only get better at it.

Morning Flight

From the earliest days of aviation, pilots have always cherished their morning flights. There is some romance in it because the air is cool and fresh and one can smell the dewdrops. The sun is still low over the horizon and has yet to cast its harsh rays onto the still slumbering earth. The low clouds and mist paint a surreal landscape making the pilot feel that he is both physically and mentally in cloud nine.

Most of my cross country flights are deliberately planned to start at dawn where possible. It would still be dark as one drives into the airport, park the car, unload the luggage, fill up the necessary papers at the club office, grab the plane keys (and the tech log if I'm not returning the same day) and proceed to the still sleeping aircraft. Unlocking the baggage compartment door just behind the passengers' seats, I would dump the luggage as forward as possible to maintain the aircraft's CG. I would then open the pilot's door and place my headset, checklist, GPS, maps and navlog on the passenger seat, check that the parking brake is on and then remove the chocks from the wheels and place them in the luggage compartment. Sometimes I would have to tow the nearly 1-ton aircraft myself to the flightline but usually the hangar help will lend a hand.

With the aircraft secure on the flightline, I would then jump into my car again and rush over to the Control Tower to file my flight plan, returning to the flightline with a signed copy for my retention. I would then begin to conduct my thorough checks including fuel and oil quantities. It would already be light then but the air is still fresh and cool. Having completed my external checks, I would then settle down in the captain's seat and proceed with the startup checks. A brief call to the tower for startup clearance follows and I'm now ready for that most beautiful experience - the grind of the starter motor, the whirring of the propeller blades and the engine coughing and sputtering to life finaly transforming into a loud roar. The vibration flows comfortingly from the engine to the seat bottom and through the control column into my left arm and my heart. What a feeling! Engine checks, a call to the tower requesting for taxi, brakes released and the aircraft crawls majestically to the runway holding point.

Runup checks, a glance at the windsock, landing lights on and a clearance from the tower before entering the runway for line up.  At the takeoff position, I get the ATC clearance from the tower and read back the instructions. I look out to the sky up ahead and see a sky similar to the one in this picture. 

It may look gloomy from the ground but that's a typical morning cloud layer. It is low, thin and silent. The runway stretches ahead with open arms. To a pilot, that strip of bitumen with its bold white markings is the most welcome site anywhere in the world. It bids you farewell each time you take off and welcomes you with open arms whenever you land, like a doting mother. It looks the same whichever airport in the world you may fly to.

"Clear takeoff!", feet on the brakes, I move the throttle forward to 2,000 revs. The engine sound is deafening but music to my ears. I do my CATS checks and having satisfied myself that all are "green", release the brakes, coax the throttle to full and roll down the runway. Sixty knots and I gently pull the control column closer to my heart. The nose comes up and we're airborne into the morning mist. A morning flight is so different from other flights. The air is dense and moist, so the air breathing Lycoming engine sucks it in like a kid quenching his thirst. There is so much power from the engine because the fuel-air mixture is thick. The dense outside air hold the wings more securely while the propeller bites into it like a knife into a wedding cake. There is hardly any wind in these early hours. The aircraft climbs straight and true, the propeller tips sending a deep throated roar to all the people still sleeping on the ground.

Soon we arrive at the base of the thin cloud layer and penetrate it rinsing the wings in the milky stuff. Then we punch out of it into the clear air above. 

We're now above that blanket of snowy white cloud stretching below us like a mat of cotton wool. The sun sends a shimmer across the mat and as I look towards its rays I hear in my head Grieg's "Morning Mood". It is so surreal, I wonder if those fighter pilots out on their dawn patrols get that same feeling each time.