Make My Trip’s Challenge. Unfortunately, they couldn’t offer the lowest, as they promise.
TheFlyingEngineer Update: A kind Spicejet FO pointed me out to Akbar Travels, which offer truly low airfares! Please do check out the last screenshot right at the bottom of this short article. Akbar travels’ low airfares, which are the lowest for all airlines and all flights that I searched for Mar 30 2013, are definitely worth a note!
MakeMy Trip dot com is strong in its advertising. It claims to bring you the cheapest fares, if not, it will pay you double the difference in fare. I wanted to see which method, and which site got me the cheapest of tickets. (and see the screenshots below: MakMyTrip couldn’t stand up to their own test).
I tried these five sites: Indigo, Spicejet, MakeMyTrip, Ixigo, Goibibo and Cleartrip. Why these six? The first two to see how much the “Major Low Cost" airlines charge, and the last four as these are very “well branded".
I set my departure date as 30th March, 2013, for a one-way flight from Delhi to Bangalore. Cheapest was my only criteria, not the flight time, time of flight, or OTPs, and I relied on the airline / website to filter my results as lowest fare first.
Here are what you should know:
1. The flight fare of Indigo and Spicejet are the same, for the date in consideration in this case.
2. Indigo charges INR 100 as “Covenience Fee" per passenger when booking through their website. Spicejet charges none, making a Spicejet ticket cheaper (in the event that both competitor’s fare prices pre-“convenience fees” are the same)
3. MakeMyTrip, Cleartrip, Ixigo/Arzoo*, and Goibibo charge a convenience fee of INR 125 per passenger. So if you’re booking a ticket early, through any of these sites, then you’ll stand to lose INR 25 when booking an Indigo flight, and INR 125 when booking a Spicejet flight!
4. Arzoo did the best job. *Now, a search on Ixibo led me to Arzoo, and Arzoo gave me by far the cheapest flight: Spicejet, INR 4017. With the “Conveninece fee" of INR 125, this came up to 4,142, which is still a good INR 1,068 cheaper than the lowest you can expect from Indigo!
Look at all my screenshots below. Read the captions carefully. So when booking a flight, search everywhere, and know that those “promise-you-the-lowest” sites may actually prove to be costlier than the airline’s parent site! Moral: Search well before buying.
As for MakeMyTrip, I wonder what they now have to say about the “lowest airfare challenge": Here’s proof that they’re not always the lowest!
Indigo’s airfare, which is priced the same as Spicejet’s, is costlier by INR 100 when booking through their website, due to the “convenience fee” that they charge.
Spicejet’s fares are priced as much as Indigo’s, but the convenience fee of INR 100 isn’t charged. This makes their fare the lower than the competition’s.
The Best Make My Trip could get me (from Indigo and Spicejet) was INR 5110, INR 1 costlier than Go Air’s fare. But add their convenience fee of INR 125, and you have INR 5235 to shell out. Even if you would have purchased Spicejet’s you’d have to pay the same: this is what all the websites charge: INR 125 on domestic!
ClearTrip couldn’t do any better than the other sites.
Ready to pay! NO, I didn’t purchase the ticket!
I don’t know how Ixigo managed it, but they had the lowest of all fares! INR 4017 + INR 125 Convenience fee = INR 4142. Compare this with Make My trip’s lowest. (below)
Make My Trip’s lowest could not beat Ixigo’s. Wonder what I can do to benefit from the lost challenge!
GoIbibo didn’t do any better than the others.
Akbar Travels, which was brought to my notice today, had the lowest steady airfares on offer!
The poem was penned by Bavicca Bharathi (photo on left), who made news in 2010 when she became India’s youngest commander, flying on the ATR 72-500s with Kingfisher Airlines.
I received the poem as a sms from her, today, and genuinely found it worth sharing! Happy Sunday, everyone!
Oh my ATR!
High Winged, and tail propped,
T-Tailed, and Prop unstopped,
O Lover boy, with dorsal fin,
With your song, my heart you pin.
Fighting the weather,
Flying with the thunder,
Amid balls of butter,
Till you begin a stutter.
Racing the strong,
Until we’re told wrong.
Then laughing the bong,
Having planned this all along.
Pushing the ceiling,
For the familiar feeling,
My heart would be me killing,
If not for your healing.
This and much we’ve done you know,
So much, I could never stow.
Come back for you, I will fat boy,
Don’t think I’ll settle for some lame toy.
The Flying Engineer’s note: The ATR 72-500 is a ~72 seat turboprop regional airplane. The airplane is high winged as the wings are above the fuselage, “T” Tailed as the elevators are above the rudder, which looks like a “T” from behind. The “tail prop” is a small rod-like structure that is hung from the aft fuselage, to prevent the airplane from completely tipping in the event of poor load distribution (which can easily happen on board this plane with provision for boarding only from the rear). Not to be confused with “Prop”, which is short for propellers: 6 long blades per propeller, lending it a diameter of 13ft. The “song” is actually the loud sound from the engine which is music only to the ears of those crazily in love with the airplane, but otherwise is a passenger nuisance. “Fighting with weather”, “flying with thunder”, “amid balls of butter (clouds)”, “till you begin a stutter” reflect the ATR 72’s inability to cruise above the weather, and being a light airplane easily tossed around in turbulent air, in comparison to the bigger jets.
The ATR72, like other turboprops, has the ability to slow down very quickly, because of its huge variable pitch constant speed propellers that can offer significant aerodynamic resistance when the power levers are pulled to flight idle. Because of this, the airplane can fly at very high speeds until just a few miles from touchdown, after which it can retard quickly. Challenging the strong headed pilots of “stronger airplanes” by “Racing the strong”, she and her crew member, like others wanting some fun, approach the runway at a high speed while behind a bigger jet aiplane, which on the other hand has to plan an approach and fly slower. Sometimes perplexed air traffic controllers would request the jet to speed up and the ATR to slow down, telling the ATR crew it’s “wrong” to fly so fast. The cockpit would erupt in laughter, for their plan in embarrassing the jets and taxing the air traffic controller (most of whom are ignorant of the aircraft’s amazing aerodynamic braking) succeeded, sometimes with a cheesy line, “You should have given us landing priority, we’re faster”. Ofcourse, that is the only time they can have fun, for “Pushing” the ceiling is the thrill that most ATR pilots get when they can, on certain occasions, cruise at a higher altitude, which infact, isn’t much.
The ATR 72 provides ample hand flying opportunities for it’s pilots. With the controls linked directly (via cables) to the control surfaces, the pilot has quite an “intimate” relationship with the airplane (“This and much we’ve done you know”). No other class of airplane flying for scheduled operators (airlines) allows for the joy of hand flying. I still don’t understand why she called the airplane “fat”. She now flies the Airbus A320 for a well performing airline, and as most pilots say, the A320 may be a marvellous airplane, but at the end of the day, is a “toy” (the mere presence of a pair of “joysticks” is one reason for some; anti-Airbus and pro-Boeing men and women have more to say), with less flying and more systems managing.
An ATR72-500. Note the tail prop: the small, hanging rod from below the fuselage near the right-rear door (closed).
VT-KFY (Airbus A321 MSN 3302). Photo by Vivek Kaul, used with permission.
My flight on the 20th of December 2009 was a memorable experience. My friend, who was a first officer with the then 5 star airline, Kingfisher, had informed the captain (an ex-IAF officer) and the lady first officer that I was their passenger on their Delhi – Bangalore flight. Comfortably seated on 37A, I found the orange juice stain I had left behind on the same seat when flying from Bangalore to Delhi a couple of days earlier.
Having been part of a huge “makeover" program at Honeywell, I was keen to gather flight data that I could possibly use for my training at the company. I sent out the “In flight form" to the crew members, scribbled on sheets from the hotel where the company had accommodated me. Most of the data is, as you will notice, from the FMS pages of the Airbus A320 family.
VT-KFY, the Airbus A321, was the first, and till date, the only A321 that I have flown on. Branded with MSN 3302, and fitted with IAE V2500 engines, I was all too interested in the then 2 year old airplane.
With the DGCA Cancelling the license of Kingfisher Airlines, this article is a tribute to an airline whose employees and flights taught me so much.
Capt M and F/O F were kind enough to fill in all requested details for IT-207 Operated by an A321, VT-KFY
Flight Plan & Navigation
VT-KFY, operating as IT-207 was planned to fly Delhi to Bangalore via airway W20S and W57S. W20S starts from the VOR at Delhi (DPN), and runs south-south east till Hyderabad International Airport’s VOR, HIA. W57S starts at HIA, and terminates at Bangalore International Airport’s VOR, BIA.
Our take off was from Runway 28, which is westerly in its orientation. After take off, the aircraft has to join the airway, for which the Air Traffic System at busy airports provide what are known as a SIDs: (standard instrument departure), which are laid down procedures that specify how an airplane taking off from a particular runway may intercept and join a particular airway. In our case, the then effective AKELA 3B SID was applicable, which details how the airplane, after takeoff from Runway 28, may turn left to intercept waypoint AKELA, which lies on W20S.
Airspace restrictions make W20S head south-south-west till waypoint KALNA, before changing direction to south-south-east towards Bhopal. This non-direct route between the two radio stations at Delhi and Bhopal makes an airplane fly 15NM extra. However, in practice, pilots request for a direct-to from AKELA to BPL, which, more often than not, is granted, saving around 10NM of ground distance. Upto waypoint IBANI, the aircraft flies in the Delhi Flight Information Region (FIR). Passing IBANI, the aircraft enters Mumbai FlR.
Mumbai is around 420NM from waypoint IBANI, and yet, the airplane must be in contact with Mumbai Control, which is physically located at Mumbai. Communication link between the airplane and the centre, through direct VHF will not be possible, as a VHF radio’s range is limited to line of sight: around 200NM. Overcoming this problem are VHF transmitters positioned in the Mumbai FIR such that when a voice transmission over VHF occurs at Mumbai, the same VHF signal is broadcasted from multiple ground transmitters. This ensures sufficient coverage throughout a FIR.
From BPL, pilots are often granted a direct-to all the way to waypoint VABDI, which saves hardly anything.
RVSM Cruising Levels
Since the route is easterly, even though slightly, ICAO specified RVSM cruising levels have to be adhered to. Airplanes flying easterly, must fly at “Odd" flight levels (FL). Example, FL 290, FL 310, FL 330, and so on. FL 290 stands for Flight Level 290, which is 29,000ft above sea level at an assumed barometric pressure of 1013.25hPa (hector Pascal) at sea level. Since it is an “assumption" that is followed by every airplane at the flight levels, all airplanes with their altimeters displaying 29,000ft with the assumption set in the altimeter, are flying at the same altitude, through the true altitude may differ by as much as 2000ft from the displayed altitude at this “Standard Barometric" pressure of 1013.25 hPa.
About 20NM from waypoint BUSBO, the aircraft is “released" from Mumbai control and “handed over" to Chennai Control, where pilots may contact the physical centre at Chennai (approximately 400NM away from BUSBO) on one of 11 VHF frequencies.
Observing the route, the direction changes toward the west (south south west) over waypoint VABDI. However, back then, when Chennai did not have sufficient radar coverage, airplanes on W57S needed to either climb 1000ft or descend 1000ft over Hyderabad. This was to change the cruise altitude from an ODD flight level to an EVEN flight level earlier than VABDI, for surveillance reasons. As far as our flight was concerned, we descended from our cruise level of FL 350 to FL 340 over Hyderabad.
We approached Bangalore from the north east, and the active runway at that time was 09, which is east facing. We were “vectored" (given compass headings to follow) by air traffic control, and “broke off" from W57S in a divergent heading. This was to take us further west, before directing us to intercept the ILS for runway 09.
The airway distance between Delhi and Bangalore is 950NM. However, with the standard instrument departure and the arrival into the airfield, the total ground distance increases to 980NM, which is an extra of 30NM. With the soon to be introduced RNP route between Delhi and Bangalore, this sector’s ground distance shall reduce significantly.
VT-KFY, for that day’s flight to Bangalore, weighed 79 tonnes, as against its all up weight of 89 tonnes. 14.5 Tonnes of fuel was uplifted, and the centre of gravity was determined at 24.7% of the Mean Aero Dynamic Chord (MAC). Permissible range is 15% to 35%, with a preference for a rear CG to improve fuel burn performance. Corresponding to this CG, the horizontal stabilizer was trimmed for nose UP to an Airbus defined position of 1 unit. This is to keep stick forces (on the pitch axis) almost neutral during takeoff.
A quick look at the Flight Crew Operating Manual for the A321 reveals that for a 980NM flight at FL350 (assumption: no winds, wind data on that day wasn’t collected), the A321 with a takeoff weight of 79 Tonnes burns approximately 6600kg of fuel for the entire flight from takeoff to landing. Approximately 200kg is burnt during startup and taxi, raising the estimated fuel burn to 6800kg. The estimated flight time between take off and landing is 2 hours 22 minutes.
The difference between the uplifted fuel (14,500kg) and the trip fuel (6800kg) was huge: 7,700kg. Bangalore’s ATF rates being higher than Delhi’s, 7.7T of fuel was “tankered" to Bangalore, which was to be used up for the next day’s flight to Delhi out of Bangalore.
A Cost Index of 18 was used for the flight. The Cost Index is a measure of the cost of time v/s the cost of fuel. The unspecified unit is kg/min, which in this case translates to 18kg of fuel being as costly as 1 minute of flight time. If the cost of fuel was low, the cost of time relatively goes up, which increases the numerical value of the cost index. If the cost of fuel goes up, the cost of time in comparison pales, lowering the numerical value of CI. Last year, most flights by Kingfisher were operated at around Cost Index 10. Lower the cost index, slower the airplane flies. For our flight that day, CI 18 corresponded to a cruise speed of Mach 0.775 under no wind conditions. There must not have been any significant winds, as the aircraft’s FMS targeted the same Mach number for cruise.
Takeoff was planned with “Flap configuration" 1+F, which is the first of four selectable “configurations" on all in-production Airbus commercial airplanes. 1+F corresponds to 18° of slats and 10° of flaps on the A321. Lower flap settings provide better fuel burn and climb performance.
Because the airplane was taking off 10 tonnes lighter than its maximum, full engine thrust for take off wasn’t required. Although the outside air temperature that night was 15°, the engine was told to produce a thrust corresponding to an outside air temperature of 44°C. Specifying a higher temperature reduces the generated thrust, saving engine life through reduced operation at the extremes. The thrust was “flex(ed) to" 44°.
With this thrust setting, the specifics of Runway 28 at Delhi, weather and the weight of the airplane, the aircraft’s take off speeds were determined as V1 : 152kts, VR : 152kts, and V2 : 156kts. V1 is the decision speed. If anything was to have happened that demanded the take off to be rejected, the decision to reject must have been made before the airplane reached the decision speed of 152kts. Attempting to stop the airplane beyond this speed is unwise, as the combination of aircraft energy and remaining runway length will prevent the airplane from stopping before the end of the runway. Vr is when the pilot pulls back on the stick to “rotate" the nose up into the air. V2 is the takeoff climb speed: the speed that is maintained on the initial climb out phase (when gaining altitude is important) before building up further speed.
Delhi’s airport is at an elevation of 777ft MSL. Takeoff thrust and take off speed (usually V2 + 10, 166kts in this case) was maintained till 1000ft above ground level, or 1720ft above MSL. At that point, the thrust was lowered to climb thrust, and the nose pitched down to maintain the same speed (V2 + 10), till 1500ft above airport elevation, or 2277ft in this case. Passing this altitude, the nose was further lowered, to build up airspeed. As the airspeed built, the flaps were retracted to “clean up" the aircraft, allowing for further acceleration. The best lift to drag speed is realised at the “O" speed, which was 217kts on that day for the given aircraft weight.
The Cruise Altitude of FL350 was determined by looking for the optimal cruise altitude at the aircraft’s weight and weather conditions. Least fuel burn is expected at the cruise altitude. Since the aircraft was flying east, the ODD flight level closest to the optimum altitude is chosen, which, in our case, was 350.
For the A321, the time to this cruise altitude, under ideal conditions at 79 tonnes, takes 25 minutes over 160 NM , burning 2000kg of fuel. Air Traffic Restrictions normally prevent most airplanes climbing out of Delhi from reaching their cruise altitude this early.
Reaching cruise, the aircraft became lighter by 2 tonnes, reducing its weight to 77 tonnes. At this weight, at FL350 under ideal conditions, the airplane guzzles around 2800kg of fuel per hour, at Mach 0.78 (450kts ground speed). Considering that the aircraft needs at minimum around 100NM to descend, and 160NM to climb, 720NM at best is traversed at cruise. This implies approximately 1hr 30 minutes in cruise, burning 3,200kg of fuel.
Starting descent, VT-KFY might have been around 73,800kg heavy. Interestingly, a light airplane descends faster. Descent from FL350 at continuous IDLE thrust takes about 17 minutes over 100NM by an A321, under ideal conditions, at the specified weight.
Our A321, for landing, was configured with full FLAPS, which corresponds to a slats of 27° and flaps of 25°. The approach speed, at the estimated landing weight of 73,000 tonnes, was 142kts. Kingfihser later adopted CONFIG 3 landings, which extends slats / flaps to 22°/21°, offering lower drag and saving fuel.
The autobrakes were set to Low (LO), one of three positions: LO, MED, HIGH. No Thrust reversers were used for landing, which was, and still is part of fuel saving procedures the world over.
Interestingly, that name is what we today associate with the European aerospace company. In the pre-Airbus era, “airbus" was a term used to describe airplanes, as above. When the Airbus Industrie was founded in 1970, they adopted the popular description. The Boeing 727 was one such very well known, and immensely successful “airbus" airplane back in its time, when it entered service in 1964.
Here is the more interesting part: American Airlines began flying the Boeing 727 in 1964, making it one of the first operators, and at one point of time, the airline operated as many as 182 Boeing 727s, making it the largest operator of the type.
This same operator, in as early as 1966, laid out the requirements for a Boeing 727 “replacement" on short to medium range routes. The requirements were: a passenger capacity of 250 – 300, twin aisle, twin engine, and good hot and high airfield performance.
The very next year, the British, French and German governments signed an MoU to develop the Airbus A300: a 300 seat, twin aisle, twin engine aircraft. With twice the maximum capacity (375 seats) of a Boeing 727 airliner (189 seats), it almost seemed like the A300 was “tailormade" for American Airlines. Intended for short and medium haul routes, the A300 was another “airbus".
American Airlines was the largest passenger operator of the type, with 35 Airbus A300s. The A300, very obviously, was deployed on routes with sufficient capacity, replacing two 727s with one A300, which in effect, was replacing 6 engines with 2, Two sets of Crew with one, and Two fuel guzzling 727s with an operationally more economical airplane that cost just twice as much as a single Boeing 727.
Possibly sensing trouble, Boeing came out with an advertisement in 1973 (beginning of article), a copy of which was published in one of that year’s print issue of Flightglobal. The advertisement was a direct hit at Airbus, in which it makes a very unfair comparison between the 727 and the alluded-to A300. At the time of the advertisement, Airbus was only 3 years old, and the A300 hadn’t yet entered service. The 727 was, at the time of the advertisement, flying for almost 10 years, and evidently, without a successful competitor, the “best selling" at that time, with orders crossing the 1000th mark in the September of 1972.
The introduction of the A300, amongst other newer airplanes, had its effect on the 727. It took 9 years to sell 1000 Boeing 727s, but 18years thereafter to sell 832 airplanes. The last Boeing 727 was built in 1984, and the 727 was retired from American Airlines’ fleet in 2002. The Airbus A300 was produced for 33 years: 12 years more than the 727, producing 561 airplanes. The A300 fleet was retired from American Airlines in 2009.
In short, the Airbus Industry was effectively formed to cater to an American Airlines requirement, and the American Airlines requirement stemmed from the Boeing 727. Which, if seen in another light, will appear as if the Boeing 727 gave birth to the Airbus Industrie.
The advertisement, very aptly, reads, “Because the Boeing 727 is the original airbus".
Change in aviation is met with heavy resistance, and even a ten year old technology is considered relatively new. With the introduction of Performance Based Navigation (PBN) in the Indian Airspace, confusion still exists on RNAV (aRea NAVigation), RNP (Required Navigation Performance), and where this RNAV/RNP are implemented in the Indian ATS.
Waypoint LATID, seen as referenced to Bangalore International Airport’s VOR (BIA). LATID = BIA/012deg/77NM or N14 28.6 E077 56.9
The basic airway system (in India and the world over) was constructed based on sensors: the VOR and the NDB stations and receivers on board the airplane, which provide the capability to fly to, or from a radio station along one of its “radials". These radio stations are scattered, purposely, across the country, and the airway system is constructed by simply “connecting the dots", and an aircraft’s position is always relative to one of these stations. Example: Waypoint LATID is 77NM from Bangalore International Airport’s VOR (BIA), on a radial of 012°of BIA.
When an aircraft’s navigation system has a little more intelligence: the ability to scan and receive signals from multiple such radio ground stations, or from self contained navigation aids, such as the Inertial Reference System (IRS), or from the globally available GPS satellite constellation, and determine the aircraft’s position in terms of the World Geodesic System 1984 (WGS-84) coordinates, it provides the ability to determine the aircraft’s absolute position, rather than referencing it to a sparse set of radio stations. Example: Waypoint LATID is N14° 28.6’ E077° 56.9’.
The advantage with absolute position is freedom in the lateral: an aircraft can determine its absolute position, and fly to another waypoint whose absolute position is known, without having to stick to a “radial" or a VOR station. The ability to fly “Direct-To" another waypoint from the present position offers an easily comprehendible advantage: fuel savings through shorter, more direct routes. This freedom in the lateral, and the ability to navigate freely in an area, gives rise to RNAV, or Area Navigation.
Indian airspace is comprised mostly of “W" routes, which are, as per AAI, exclusively available for domestic operators only. According to ICAO Annex 11, a “W" route is NOT an Area Navigation Route, which means, the airway is constructed with reference to ground radio beacons, and are mostly direct from one beacon to another.
The other airways in India are “A", “B", “G", “L", “M", “N", “P", “Q", “R", “UL", “UM". Of these, “L", “M", “N", “P" and “Q" are area navigation routes. This means that these routes are not constrained to fly between ground based radio stations, but are instead optimised, more direct routes that save fuel. The “Q" routes were recently introduced in 2012, in July.
Since flying these routes implies a reliance on the aircraft’s complex navigation system (which authorities have no operational control of) rather than the simpler ground referenced navigation system (which authorities maintain), it is imperative that in the interest of safety, the complex area navigation system be capable of a certain navigation accuracy, also termed the navigation performance.
Certain routes, and certain procedures may require a higher navigation accuracy and its associated certainty, while others may be less demanding. To quantify these “higher and lesser" accuracies, the term “Required Navigation Performance" (RNP) was introduced, which stipulates the minimum navigational accuracy that must be guaranteed, with a certainty of 95% availability.
With RNP, of the many requirements, the aircraft must be capable of displaying the Actual Navigation Performance (ANP). As long as the actual navigation performance is within the limits of the RNP, everyone’s happy. But if the ANP gets worse than the RNP, that’s when Air Traffic Control must be notified so they can keep close eye on you and other airplanes in relation to your aircraft, and direct you based on conventional navigational practices.
The Area Navigation Routes – “L", “M", “N", “P" – are all RNP 10 in India. The newly introduced “Q" routes, are all RNP 5. This means that your aircraft’s navigation accuracy must be better than 5 NM if it is to fly along the newly introduced 7 “Q" routes: Q1 – Q7. If however the ANP of the aircraft is 5.5 NM, then the accuracy is not enough to fly the “Q" routes, but accurate enough to fly thee RNP 10 routes: “L", “M", “N", “P".
Q1, W13N, and a Direct route as shown between Mumbai (BBB) and Delhi (DPN) VORs
The benefits of the RNP routes are evident. The newly introduced “Q" routes connect Delhi to Mumbai, Ahmedabad, Udaipur, and Vadodra. Picking “Q1", which is Mumbai to Delhi (BBB- DPN), there are 13 waypoints in between the starting (BBB) VOR and the ending (DPN) VOR. Except for one, none of the other waypoints are ground based radio aids. The total ground distance between Mumbai and Delhi along Q1 is 633NM. The domestic non-RNAV “W13N" route between Mumbai and Delhi, has 5 waypoints in between, three of which are ground based radio aids (VOR). The ground distance along W13N is 653NM. A347, another non-RNAV route between Mumbai and Delhi, has 9 waypoints in between, three of which are ground based radio aids. The ground distance along A347 is 735NM. Compared to W13N and A347, Q1 saves 20NM and 102NM of ground distance, which translates to a saving of between 2 minutes and 14 minutes of flying time. A heavy Airbus A320, flying at FL350 at 76Tonnes, can save between 124 kg and 634 kg of fuel, which translates to a saving of between INR 11,000 and INR 56,227 per Mumbai-Delhi flight. Another advantage is the smooth flight path, as opposed to the zig-zag of non-RNAV routes.
Indigo’s 11 daily direct flights from Mumbai to the capital can save the airline about INR 1,21,000 per day, one way alone! Air India, with 12 direct flights, saves INR 1,32,000 one way, per day.
Aircraft with high navigation performance are allowed to fly the RNP routes. With higher accuracy, more airplanes can be squeezed on an airway. The “Q" routes allow aircraft to aircraft longitudinal separation of 50NM, while W13N allowed for a 10 minute separation, which translates to around 75NM. Theoretically, up to 13 airplanes may now fly on Q1, at any point of time, as compared to 9 on W13N. The capacity of the Indian Air Traffic System (ATS) has increased 44% on this route alone.
RNP and RNAV arrivals and departures are already in use, explained in another article which shall follow soon.
The ATR 72-500 has its idiosyncrasies. In the cockpit is a “seat position sight gauge", which are three small, coloured balls that allow a pilot to adjust his viewpoint to a position that ATR deems appropriate, allowing for a “correct view of instrument panels as well as runway environment". The photo above shows the ATR 72 cockpit, with the sight gauge enlarged in the inset. If the first officer is to have his viewpoint right, he must adjust his seat height and position such that when looking at the three balls, the left white ball is obscured by the red centre ball.
Eye Level Indicator on the Q400
Interestingly, this gauge is not found in the Boeings, where the recommended method of adjusting the viewpoint is different. The ATR 72-500/600’s competitor, the Q400, however, has something similar, called the “eye level indicator", as may be seen in the second photo. The Airbuses, not surprisingly, have a sight gauge similar to that found on the ATR.
Possibly one of the smartest first officers in India told me, after seeing me so diligently adjusting my P1 seat in an ATR 72-212A (500) to the correct viewpoint, that I was too high. Apparently, the seat position sight gauge does do its job well, but it isn’t something you’d want to level your eye with on an airplane like the ATR 72-500. Why? Visual perspective.
With the eyes adjusted, the view is good, and clean. But with the ATR 72, (and the Q400) one has to be very careful with the flare: the airplane’s fuselage is long and low, and a tail strike is easy. Another complication is the aircraft itself: having a constant speed propeller means that when you pull back on the power levers, the pitch angle of the propeller blades changes to “fine" (almost perpendicular to the direction of the airplane’s travel through the air), resulting in a significant increase in drag. If the flare is more than required, and the airplane balloons*, pulling back on the power levers is the last thing one would want to do, as the drag would make the aircraft drop to the runway like a stone! So one would add power to keep the airplane up, and this will eat up more runway: Messy indeed. And for him, with the ATR recommended viewpoint, comes the tendency to flare more than required.
*[The term “balloon" refers to a landing airplane that rises slightly before touching down. Ballooning is typically caused by excessive airspeed or excessive back pressure being applied to the flight controls by the pilot during the landing flare]
So what he does is to sit lower than the recommended view point: low enough to make him actually look up to see outside. This works well for him, and few others who have settled for this more comfortable, though not recommended, seating technique. Anything that works!
What can go wrong just because of an improper flare?
On 9th May, 2004, N438AT, an ATR 72-212, during the approach to landing, the captain stated to the first officer (flying), “you better keep that nose down or get some power up because you’re gonna balloon.". After the airplane crossed the runway threshold, the captain stated, “power in a little bit, don’t pull the nose up, don’t pull the nose up." The captain then stated, “you’re ballooning,". The airplane touched down with a vertical load of 1.3G, bounced into the air, touched down a second time, then bounced into the air with a nose up of 9°, climbed to 37 feet, and touched down a third time with a vertical load of 5Gs. After a fourth touchdown, the badly damaged airplane came to a stop outside the runway.
On 17th September, 2005, D-ANFH, an ATR 72-212A, Just prior to touchdown, the co-pilot pitched the aircraft nose up to an attitude of 6.5º. The aircraft landed hard on the runway and bounced; in the course of the initial touchdown, the lower rear fuselage struck the runway surface.
On 23rd May 2006, G-BWDA, an ATR 72-202, towards the conclusion of a brilliant approach, the first officer closed the power levers at 10ft and flared the aircraft. The airplane touched down, bounced into the air, and the attempt to arrest the sinking of the aircraft to the ground, pulled back on the control column, striking the tail.
And yes, I have also heard some of my friends say, “Oh damn, I forgot to flare!"