Question time #44 Answer !
Some seldom seens, seen today.
Crosswind After-Landing Roll
Particularly during the after-landing roll, special attention must be given to maintaining directional control by the use of rudder or nosewheel steering, while keeping the upwind wing from rising by the use of aileron.
When an airplane is airborne, it moves with the air mass in which it is flying regardless of the airplane's heading and speed. When an airplane is on the ground, it is unable to move with the air mass (crosswind) because of the resistance created by ground friction on the wheels.
Characteristically, an airplane has a greater profile or side area, behind the main landing gear than forward of it does. With the main wheels acting as a pivot point and the greater surface area exposed to the crosswind behind that pivot point, the airplane will tend to turn or weathervane into the wind.
Wind acting on an airplane during crosswind landings is the result of two factors. One is the natural wind, which acts in the direction the air mass is traveling, while the other is induced by the movement of the airplane and acts parallel to the direction of movement. Consequently, a crosswind has a headwind component acting along the airplane's ground track and a crosswind component acting 90° to its track. The resultant or relative wind is somewhere between the two components. As the airplane's forward speed decreases during the after-landing roll, the headwind component decreases and the relative wind has more of a crosswind component. The
greater the crosswind component, the more difficult it is to prevent weathervaning.
Retaining control on the ground is a critical part of the after-landing roll, because of the weathervaning effect of the wind on the airplane. Additionally, tire side load from runway contact while drifting frequently generates roll-overs in tricycle geared airplanes. The basic factors involved are cornering angle and side load.
Cornering angle is the angular difference between the heading of a tire and its path. Whenever a load bearing tire's path and heading diverge, a side load is created. It is accompanied by tire distortion. Although side load differs in varying tires and air pressures, it is completely independent of speed, and through a considerable range, is directional proportional to the cornering angle and the weight supported by the tire. As little as 10° of cornering angle will create a side load equal to half the supported weight; after 20° the side load does not increase with increasing cornering angle. For each high-wing, tricycle geared airplane, there is a cornering angle at which roll-over is inevitable. The roll-over axis being the line linking the nose and main wheels. At lesser angles, the roll-over may be avoided by use of ailerons, rudder, or steerable nosewheel but not brakes.
While the airplane is decelerating during the after-landing roll, more and more aileron is applied to keep the upwind wing from rising. Since the airplane is slowing down, there is less airflow around the ailerons and they become less effective. At the same time, the relative wind is becoming more of a crosswind and exerting a greater lifting force on the upwind wing. When the airplane is coming to a stop, the aileron control must be held fully toward the wind.
Criminal charges against MAT
Currently there is no resumption of services on behalf of MAT in sight. This leaves 180 employees in doubt of their position within the carrier. With MAT grounded, Serbia’s Jat Airways has now become the largest carrier operating out of Macedonia with a total of 11 weekly flights, which will be increased to 13, starting June 1.
Going going; Indian Peaks ; Gone
Above is 315B Lama , c/n 2528 , XC-CIP. According to the FAA this is N9000R with Pacific Aeromotive Corp of Erie, Colorado and was cancelled on 29-05-2003 as sold to NZ.
.......But soon to depart
Recent addition............
Crosswind Touchdown
If the crab method of drift correction has been used throughout the final approach and roundout, the crab must be removed the instant before touchdown by applying rudder to align the airplane's longitudinal axis with its direction of movement. This requires timely and accurate action. Failure to accomplish this will result in severe side loads being imposed on the landing gear.
If the wing-low method is used, the crosswind correction (aileron into the wind and opposite rudder) should be maintained throughout the roundout, and the touchdown made on the upwind main wheel.
During gusty or high wind conditions, prompt adjustments must be made in the crosswind correction to assure that the airplane does not drift as the airplane touches down.
As the forward momentum decreases after initial contact, the weight of the airplane will cause the downwind main wheel to gradually settle onto the runway.
In those airplanes having nosewheel steering interconnected with the rudder, the nosewheel may not be aligned with the runway as the wheels touch down because opposite rudder is being held in the crosswind correction. To prevent swerving in the direction the nosewheel is offset, the corrective rudder pressure must be promptly relaxed just as the nosewheel touches down.
Boeing 737-8FE ZK-PBL gone
Charter wars - continued
However, Stamenković says that the charter carriers from these countries are not to blame rather that it is “individual interests”. “The Government of Serbia sent a letter earlier this year to travel agents in the country stating that during the summer seasons the same rules will apply as last year, which means that foreign charter carriers will not transport Serbian tourists. Upon this order 97% of travel agencies made an agreement with Jat Airways for summer charters. However, 1 tourist agent made an agreement with foreign carriers, even though this is illegal. This is how the problem began”, explains YUTA’s director. He did not wish to name which tour operator is in question. Serbian passengers do not care with which carrier they will travel to their summer vacation since ticket prices are all included in their holiday packages. Stamenković says that if the government does not care for Jat to make 25 million Euros, like it did last year thanks to charter traffic, then it should clearly announce this.
No matter of the outcome of Jat’s charter operations to Egypt and Turkey this summer, all of Jat’s scheduled services to Istanbul are not affected by this decision as charter licenses are spate from regular licensed flights. In a study conducted during February and March this summer Serbs have chosen Greece as their number one holiday destination followed by Bulgaria, Turkey and Egypt.
Dornier 228-202 ZK-VIR gone.
Crosswind Roundout (Flare)
Generally, the roundout can be made like a normal landing approach, but the application of a crosswind correction is continued as necessary to prevent drifting.
Since the airspeed decreases as the roundout progresses, the flight controls gradually become less effective. As a result, the crosswind correction being held will become inadequate. When using the wing-low method, it is necessary to gradually increase the deflection of the rudder and ailerons to maintain the proper amount of drift correction.
Do not level the wings; keep the upwind wing down throughout the roundout. If the wings are leveled, the airplane will begin drifting and the touchdown will occur while drifting. Remember, the primary objective is to land the airplane without subjecting it to any side loads that result from touching down while drifting.
Jetstream 41 ZK-JSM gone.
An undercarriage retract at the start of its delivery flight from Prestwick on 07-04-95 saw its delivery departure delayed until 29-04-95 when it nipped across the Pond to become C-FTVN with Air Atlantic (1995) Ltd at Halifax, Nova Scotia.
It ferried into Nelson on 25-01-2002 to become ZK-JSM on 07-02-2002 with Origin Pacific Airways. It was re-listed to Honk Aviation of Auckland on 15-09-2006 and departed Nelson on 17-09-2006 for Auckland and then on to Tonga and NZ cancellation on 22-09-06 as it became A3-XRH with Peau Vava'u Airline. From November 2006 until February 2007 it was parked up at Ardmore during civil unrest in Tonga. It returned there only to have the airline go defunct in January of 2008. It returned to Auckland and Nelson for storage on 09-04-2008. It was re-registered back to ZK-JSM with Honk Aviation on 09-12-2008. A post storage test flight was carried out on 07-01-2009 with an acceptance flight on 03-04-2009.
Finally departed Neslon for Auckland and Norfolk Island on 04-04-09 and onward to Brisbane and Townsville the next day. Here it was repainted before moving onward to someplace in Africa.
Top pic shows it withdrawn at Nelson, minus prop, on 14-12-2005.
Pic below shows A3-XRH at Nelson on 20-05-2008 following its return from Tonga.
Adria interested in Niš service
However, Niš could be getting a major boost this year. Turkish companies such as Atlasjet, Pegasus Airlines and Sky Airlines are interested in commencing services and Jat is hoping of starting services from Niš to Vienna. Niš is Serbia’s third largest city but it cannot rely on wide scale passenger traffic. The city lacks foreign investment therefore limiting business travel. However, it is attractive to some carrier because of its extreme low costs (many airlines have been offered free handling fees for the first 6 months of operations) and its close proximity to the mountain resort of Kopaonik is an added plus. Other carriers which used to operate flights to Niš were Montenegro Airlines on a seasonal basis (from Tivat) although it has decided not to return this year and Thompsonfly which continues with winter charters to London and Sofia. The authorities believe that the airport’s future lies in cargo operations and plans have begun to develop the airport in a major cargo hub for South Eastern Europe. Niš and its airport were heavily damaged during the 1999 NATO bombing of Serbia while the airport was reopened in 2004 after its reconstruction was funded by the Norwegian Royal Family. Late last year the airport was cleared of all cassette bombs which were found in close proximity, undetonated since 1999. This work was carried out by Russian experts.
Taking off your Radio Controlled Jet
- As we know the basics of any take off that they are performed into the wind. You need to have a windsock to know the direction of wind. Although all major air fields have but you can take a hint from your hanky. Intensity of the wind is to be judged as well, too much of a wind can make the moves erroneous. You need to position your rc jet into the wind and also mark any land mark not of much height because you are going to make a turn above it after climbing a height.
- Positioning your remote controlled airplane is very important. Make sure that it is placed in the middle of the runway because sometimes rc airplanes go cut sides and go off the runway. Your rc aircraft is facing the wind and positioned between the runway.
- Some of the air fields have marked pilot positions, these are the spots from where you fly your rc airplane if you are using an airfield, get there, choose a nearby your rc plane.
- Better take offs are always about swift speed catching. You need to give smooth but full throttle in a short time so that air cuts the controls surfaces faster and give you edge in lifting your rc jet in the air.
- You will be required to use a little rudder here and there to keep your remote controlled aircraft in the middle of the runway and in a straight line so it can catch up speed faster. Use a small up elevator if you are flying a tail dragger, this will keep your rc plane to nose down.
- After seeing your rc jet gaining full speed, you need to pull back smoothly and gently, if you make it climb too steep, your rc airplane can catch a stall which can happen due to low altitude. Keeping it in a gradual climb and straight for a little while will give it stability. You may want to apply correction to bank by tapping the rudder or aileron stick. You will have to plan your height from where you want to take a turn over the land mark chosen earlier.
- After reaching the land mark location for the turn, reduce the throttle to half and level off. Take the turn in the direction you want by banking your rc jet or aircraft while maintaining the altitude so you don’t find your remote controlled plane ditching on the ground.
That’s it; you have made a very smooth take off. You deserve a pat, enjoy flying.
Zane
17,200 hours
I dug this out of the dreaded shoe box and added to this blog 28-04-09 & 1700hrs.
Below a pic taken 27-04-2009
Crosswind Approach And Landing
Many runways or landing areas are such that landings must be made while the wind is blowing across rather than parallel to the landing direction. All pilots should be prepared to cope with these situations when they arise. The same basic principles and factors involved in a normal approach and landing apply to a crosswind approach and landing; therefore, only the additional procedures required for correcting for wind drift are discussed here.
Crosswind landings are a little more difficult to perform than crosswind takeoffs, mainly due to different problems involved in maintaining accurate control of the airplane while its speed is decreasing rather than increasing as on takeoff.
There are two usual methods of accomplishing a crosswind approach and landing—the crab method and the wing-low (sideslip) method. Although the crab method may be easier for the pilot to maintain during final approach, it requires a high degree of judgment and timing in removing the crab immediately prior to touchdown. The wing-low method is recommended in most cases, although a combination of both methods may be used.
Charter wars
YUTA believes that letting foreign charter carriers commence services to Serbia could be a move which will directly harm the national interests of the country and the national carrier. Although Jat does not decide which carrier is allowed to fly to Serbia it has joined YUTA in its pursuit to get rid of these airlines. In order for other carriers to fly to Serbia they need to be issued a license by the Serbian Civil Aviation Authority. The authority informs Jat of which airline would like to commence services to Serbia and Jat gives their opinion if these should go ahead or not. However, Jat’s decision is not binding and is simply in place to see what the national carrier thinks. The trouble is that the Turkish and Egyptian authorities are now angry at Serbia and will take away Jat’s charter license if their carriers are not allowed to commence services to Belgrade and Niš.
Nevertheless it seems that the issue has been resolved for now, at least when Jat is in question, as the airline’s charter flights to Cairo, Hurghada, Sharm el-Sheik and Antalya all departed on Sunday and arrived in Belgrade today.
The airlines which are interested to commence charter services to Serbia is the Egyptian Lotus Air which would fly to Belgrade from Marsa Alam from June 15 to October 29 and the Turkish charter companies Pegasus Airlines, Atlasjet and Sky Airlines which would connect Antalya to Belgrade via Niš.Jat’s charter services have been a big success since Montenegro Airlines ended charter operations from Belgrade in the summer of 2006. With practically a 100% share of the charter flights it would be difficult for Jat to lose it now, particularly when its struggling in the scheduled flights sector. The only charter carrier which has been issued with a license so far is the Tunisian Nouvelair from Monastir to Belgrade.
Crosswind Final Approach
The crab method is executed by establishing a heading (crab) toward the wind with the wings level so that the airplane's ground track remains aligned with the centerline of the runway.
This crab angle is maintained until just prior to touchdown, when the longitudinal axis of the airplane must be aligned with the runway to avoid sideward contact of the wheels with the runway. If a long final approach is being flown, the pilot may use the crab method until just before the roundout is started and then smoothly change to the wing-low method for the remainder of the landing.
The wing-low (sideslip) method will compensate for a crosswind from any angle, but more important, it enables the pilot to simultaneously keep the airplane's ground track and longitudinal axis aligned with the runway centerline throughout the final approach, roundout, touchdown, and after-landing roll. This prevents the airplane from touching down in a sideward motion and imposing damaging side loads on the landing gear.
To use the wing-low method, the pilot aligns the airplane's heading with the centerline of the runway, notes the rate and direction of drift, and then promptly applies drift correction by lowering the upwind wing.
The amount the wing must be lowered depends on the rate of drift. When the wing is lowered, the airplane will tend to turn in that direction. It is then necessary to simultaneously apply sufficient opposite rudder pressure to prevent the turn and keep the airplane's longitudinal axis aligned with the runway. In other words, the drift is controlled with aileron, and the heading with rudder. The airplane will now be sideslipping into the wind just enough that both the resultant flightpath and the ground track are aligned with the runway. If the crosswind diminishes, this crosswind correction is reduced accordingly, or the airplane will begin slipping away from the desired approach path.
To correct for strong crosswind, the slip into the wind is increased by lowering the upwind wing a considerable amount. As a consequence, this will result in a greater tendency of the airplane to turn. Since turning is not desired, considerable opposite rudder must be applied to keep the airplane's longitudinal axis aligned with the runway. In some airplanes, there may not be sufficient rudder travel available to compensate for the strong turning tendency caused by the steep bank. If the required bank is such that full opposite rudder will not prevent a turn, the wind is too strong to safely land the airplane on that particular runway with those wind conditions. Since the airplane's capability will be exceeded, it is imperative that the landing be made on a more favorable runway either at that airport or at an alternate airport.
Flaps can and should be used during most approaches since they tend to have a stabilizing effect on the airplane. The degree to which flaps should be extended will vary with the airplane's handling characteristics, as well as the wind velocity.
MAT grounded!
MAT’s management says that passengers were never in danger and that the airline’s pilots and technicians would never allow the aircraft to operate have passengers ever been in danger. Furthermore the carrier says the last time the Macedonian Civil Aviation Authority undertook a safety review of the airline they found no faults. MAT says that it has ordered the replacement part which will take a few days to arrive because “it cannot just arrive over night”, Kristevski said. The replacement will cost the airline 50.000 American dollars, a major figure for the cash strapped carrier. The latest turn in the MAT drama has led to the cancellation of all flights this weekend which included flights from Skopje to Zurich and Istanbul.
It is now uncertain what awaits MAT. The latest development can only intensify the takeover of the carrier, with Serbia’s Jat Airways expected to be the new owners. MAT's managment is hoping that once the replacement part arrives the carrier will be able to fly again. He accuses the Macedonian Civil Aviation Authority of double standards as they have issued the Turkish charter carrier Tarhan Tower Airlines with a license to fly from Macedonia even though the Turkish Civil Aviation authority revoked the airline’s license in 2007 and the airline has been bankrupt ever since.
MAT has now been left without any aircraft as its other fleet member, a CRJ900, has been stored in Ljubljana after MAT was unable to pay for its operations. According to a poll on this blog earlier this year 61% of those that voted believed that MAT will no longer be flying by the end of 2009.
More on the Kittyhawk ZK-VWC
Ground Effect
Ground effect is a factor in every landing and every takeoff in fixed-wing airplanes. Ground effect can also be an important factor in go-arounds. If the go-around is made close to the ground, the airplane may be in the ground effect area. Pilots are often lulled into a sense of false security by the apparent "cushion of air" under the wings that initially assists in the transition from an approach descent to a climb. This "cushion of air," however, is imaginary. The apparent increase in airplane performance is, in fact, due to a reduction in induced drag in the ground effect area. It is "borrowed" performance that must be repaid when the airplane climbs out of the ground effect area. The pilot must factor in ground effect when initiating a go-around close to the ground. An attempt to climb prematurely may result in the airplane not being able to climb, or even maintain altitude at full power.
Common errors in the performance of go-arounds (rejected landings) are:
Failure to recognize a condition that warrants a
rejected landing.
Indecision.
Delay in initiating a go-round.
Failure to apply maximum allowable power in a timely manner.
Abrupt power application.
Improper pitch attitude.
Failure to configure the airplane appropriately.
Attempting to climb out of ground effect prematurely.
Failure to adequately compensate for torque/Pfactor.
Code shares in abundance
For those interested, Croatia Airlines has been a regional Star Alliance member since 2004, with its membership sponsored by the German giant Lufthansa.
SUN 'n FUN 2009!
Great (and getting hot!) weather and a good, if not record-breaking, turnout mark the beginning of the EAA Sun 'n Fun flyin.
The exhibitor turnout is likewise somewhat down, although Dan Johnson's LSA Mall at the entrance is filled with aircraft and lots of serious interest from potential buyers, as in previous shows.
I've talked with many LSA companies here who say there are more serious buyers, fewer "tire-kickers".
Some LSA makers like Flight Design have racked up aircraft sales already. Others are still hoping to do business: it depends on who you talk to on whether the show is better or worse than expected. Expectations due to the economic times were not high to begin with, so it's too early to put a number on the overall picture.
Lots of new developments though, with more details to come here, such as:
* a new electric/Rotax hybrid engine that will boost economy and provide electric power safety backup in emergencies, announced at AERO Friedrichshafen
* Evektor passes LAMA audit
* Legend Cub offers sub-$100,000 "Aeronomic Stimulus" SLSA, and new Garmin 696 installation
* EAA presents Earth Day celebration with electric LSA prototype in center of the LSA exhibitors in the southeast display mall.
And lots more to come.
Configuration:Intentional Slips
When takeoff power is applied, it will usually be necessary to hold considerable pressure on the controls to maintain straight flight and a safe climb attitude. Since the airplane has been trimmed for the approach (a low
power and low airspeed condition), application of maximum allowable power will require considerable control pressure to maintain a climb pitch attitude. The addition of power will tend to raise the airplane's nose suddenly and veer to the left. Forward elevator pressure must be anticipated and applied to hold the nose in a safe climb attitude. Right rudder pressure must be increased to counteract torque and P-factor, and to keep the nose straight. The airplane must be held in the proper flight attitude regardless of the amount of control pressure that is required. Trim should be used to relieve adverse control pressures and assist the pilot in maintaining a proper pitch attitude. On airplanes that produce high control pressures when using maximum power on go-arounds, pilots should use caution when reaching for the flap handle. Airplane control may become critical during this high workload phase.
Delta Yankee Kermit and a Cutey
Above is the Dave Mitchell Rans S6ES Coyote 11 ZK-DYM c/n 4051657 , known as "Kermit" and using the callsign "Delta Yankee Kermit" (locally).
I do like a bit of individuality and admit that I use "fox" instead of the full "Foxtrot".
Then an unusual event. This colourful Eurocopter EC 120B from Garden City Helicopters, ZK-IQT , c/n 1370 , arrived and did an overhead rejoin and full curcuit, instead of the more common zoom, hover & dump down at the fuel pump. Well done ! This has been with Garden City since being imported in May of 2005.
One & the same. ZK-JKZ now ZK-JHU
New flights as profits soar
Serbia’s largest airport has also reported that there will be an influx of new services this summer. Tunisian charter carrier Nouvelair will begin services to Belgrade from its hub in Monastir. Flights will operate twice per week which will add significant competition for the two carriers already operating on this line. There are a total of 11 weekly flights from Belgrade to Monastir with Jat Airways operating 7 flights and Tunisair operating the other 4. The new service will lead to 13 flights per week between the two cities. Meanwhile Turkish Airlines will increase its flights from 5 weekly to daily by the end of May, from Istanbul. The low-cost Norwegian Air Shuttle will introduce new services to Stockholm from May 23 while LOT Polish Airlines will begin with 4 weekly flights to Warsaw which will provide excellent short connection times for passengers transiting to New York, Chicago and Toronto. Jat will commence services to Abu Dhabi in May with flights operating twice per week.
ZK-HJK and ZK-IJF
Photographed 1 minute after its exit from the paint shop at Ardmore is Hawkes Bay based Eurocopter AS350 B3 ZK-IJF. This flingwing was added to the register in late February.
Lentokoneen aerodynaaminen suunnittelu -luento 5.5.2009 SIL-luokka klo 17
In English: There is a lecture about aerodynamics arranged at Malmi SIL class 5th May 2009. The language in the lecture is Finnish and the lecturer is going to be Juha Karjalainen from Helsinki University of Technology.
Attitude:Intentional Slips
Attitude is always critical when close to the ground, and when power is added, a deliberate effort on the part of the pilot will be required to keep the nose from pitching up prematurely. The airplane executing a go-around must be maintained in an attitude that permits a buildup of airspeed well beyond the stall point before any effort is made to gain altitude, or to execute a turn. Raising the nose too early may produce a stall from which the airplane could not be recovered if the go-around is performed at a low altitude.
A concern for quickly regaining altitude during a go-around produces a natural tendency to pull the nose up. The pilot executing a go-around must accept the fact that an airplane will not climb until it can fly, and it will not fly below stall speed. In some circumstances, it may be desirable to lower the nose briefly to gain airspeed. As soon as the appropriate climb airspeed and pitch attitude are attained, the pilot should "rough trim" the airplane to relieve any adverse control pressures. Later, more precise trim adjustments can be made when flight conditions have stabilized.
ZK-IHC with Garden City Helicopters.
No Easter = no passengers
The main reason the carrier saw such large declines in most sectors is because of the absence of Easter. Last year Easter was in March which usually sees increased passenger activity. This year however the Easter holiday fell into the month of April. Jat will hope that with Easter and the launch of its popular Belgrade – Pula service it will see small declines in passenger numbers this April, if not even a modest rise in passengers.
Kittyhawk takes flight for the first time in 65 years!
http://www.pacificwrecks.com/aircraft/p-40/A29-414.html
The aircraft was test flown by Frank Parker, experienced Kittyhawk handler. The test flight programme will be fairly brief with the aircraft expected to depart NZ at the beginning of May for its new home.
Colin Hunter was on hand to capture this historic moment!