SpiceJet introduced the Q400s in 2011 as a game changer. The move was not in line with what low cost carriers world over had practiced. After Air Deccan, SpiceJet became the second low cost carrier (which we prefer to call low fare carrier) in India to adopt a dual fleet strategy.

The reasoning was simple enough. First, India is a country where certain routes are saturated while many routes with potential are unexplored. This is largely due to the misconception of a ‘one aircraft fits all’ strategy. Having an oversized airplane (in terms of seats) fly on routes that have insufficient demand only leads to poor control on pricing and revenue management. The hope that some routes will eventually grow to cater to the large jet is unwise. The right sized airplane matters. Second, blindly copying and pasting to India a low cost model that worked wonders overseas is again unwise. Every market is unique, and requires its own study.

But perhaps, SpiceJet wasn’t ready to handle the Q400. Perhaps, SpiceJet did not pull off a good deal with Bombardier. Perhaps, SpiceJet’s study was half baked. Perhaps, SpiceJet was short sighted and the turboprop may have performed better in the hands of a smarter, shrewder operator. But most importantly, perhaps the Q400 fleet and staff were meted with a step-motherly treatment.

Optimisations in the Q400 fleet are only now becoming visible. Ajay Singh is using pressure tactics to squeeze Bombardier to give the airline more. A few Q400s are expected to join the fleet, with the insurance payoff from the Q400 that was written off in a runway excursion at Hubli. The Q400 fleet size reduced to 14 Q400s from 15, and one Q400 that was cannibalised has now been restored and is apparently due for a maintenance test flight. The airline has also started to optimally fly its airplanes, to realise fuel savings and time savings. Time saved can accumulate to fly an additional sector. The airline is also working to better integrate the Q400 network with its Boeing network. After all, the Q400s are intended to primarily serve as feeders. Salaries of the Q400 flight crew have been brought on par with those on the Boeings.

The airline, four years late, has realised that the Q400 cannot play the ATR game. The Q400 must play the Q400 game. The turboprop has been designed to cater to routes that are as thin as the ATR’s, but longer than what the ATR s suited to fly. And that the USP of the Q400 is its speed.

The difference between the games of the Q400s and ATR72s? The Q400 focuses on maximising revenue potential, while the ATR72 focuses on minimising costs. Those aren’t the same variety of apples to compare.

Simply put, the management wasn’t ready for the Q400.

The Q400s, today

As of today, 13 of the 14 Q400s in the airline’s fleet are active, with the 14th expected to join soon. Effective 16th July, these 13 Q400s will operate 116 flights a day, operating for a total of 149:20 hours each day, and deploying a capacity of 9048 seats on the network, daily.

Each Q400 flies on average almost 9 flights a day, and is utilised to just a minute short of 11:30 hrs per day, per aircraft. A year ago, the utilisation was at 10:20 hrs.

Of the 116 departures, the airline flies 76 routes (where the onward and the return are treated separately) between 38 city pairs. This is on average a frequency of 1.5 on each route. The Q400s serve 28 destinations, resulting in an average of 1.3 city pairs from each destination.

Of the 38 city pairs, 10 are monopoly sectors. Of the 38 city pairs, 34 are exclusively operated by the Q400s by SpiceJet. Of the 28 destinations, 15 are exclusively Q400 destinations. Refer the diagram below.

The Q400 flies the longest turboprop sector in India, between Jabalpur and Mumbai. Sectors like this are what the Q400 are better suited for: longer than those of an ATR, shorter than those suited for a jet. Monopoly sectors are in yellow. Nearly 90% of the city pairs are exclusively operated by the Q400 at SpiceJet.

Block times for the sectors do not necessarily match the distances. The sector block times, for the same sectors in the same order, are graphed below:

The most important stations for SpiceJet’s Q400s are, in order of departures, Hyderabad, Chennai, Delhi and Bangalore. Bangalore, despite being a hub, is not a base for the Q400s.

Jabalpur is important to the airline. Q400s from Delhi are swapped with the Q400s from Hyderabad at Jabalpur, necessary for maintenance which is at Hyderabad. Q400s from Chennai swap with the Q400s at Hyderabad through the Goa flights.

53% of the stations served by the Q400 are exclusive Q400 stations for SpiceJet.

Of the above stations, Belgaum and Tuticorin are exclusively served by SpiceJet, and operated to by the Q400s. Belgaum and Tuticorin are examples of airports that are either operationally unfeasible or commercially unviable to operate using a 180 seat jet aircraft. Most of the Q400 sectors listed here are commercially unviable for a 180 seat jet (the market isn’t yet sufficiently big), and atleast 40% of the sectors are not advisable to deploy a jet on, due to short sector lengths.

Typically, a regional jet with similar seats offers better operating economics and greater productivity when sector distances exceed 250 – 300NM. Average sector length for SpiceJet’s Q400s is 260NM, which speaks well about the way in which the asset is being used. 53% of the 38 sectors are below the average of 260NM, and 74% of the 38 sectors are below 300NM.

Flying the Q400 faster to save fuel?

The Q400 can be flown in one of four speed schedules – Long Range Cruise (LRC), High Speed Cruise (HSC), Intermediate Cruise Speed (ISC – between HSC & LRC), and Maximum Cruise rating (MCR). When arranged in order of increasing speeds, this is LRC-ISC-HSC-MCR.

Among 16 techniques in which an operator may realise fuel savings, optimisation of cruise speeds realises the largest potential gain. The Specific Air Range (SAR) curve below shows the distance travelled per pound of fuel. Higher the SAR, the longer the distance that the Q400 can cover for the same quantity of fuel.

While LRC (red line) would be the choice of speed for any operator who considers only fuel costs, SpiceJet used to operate its aircraft at ISC (purple line). This burnt more fuel, but saved time, which results in reduced time-related costs, and higher productivity.

Of late, SpiceJet has been flying its Q400s at HSC, for flights of around 1 hr in flight time (not block time). This translates to flights of sector distances of 300NM and below, which are 74% of all sectors flown by the Q400s at SpiceJet. Flying at HSC should, according to tables, burn more fuel, but pilots do report savings of around 150Kgs of fuel per sector. 150Kgs of fuel saved is around 14% of the trip fuel for a one hour flight time sector, which is a significant amount.

Such high fuel saving percentages with an increase in speed is not possible. The only explanation could be a host of other procedures that have been implemented that impact the overall fuel consumption. Better routing to take advantage of winds can have significant impact on fuel burns. Optimisation of weights, climb and descent profiles, improvised taxi procedures and approaches, use of detailed performance tables, and better APU management are some of the ways which fuel burn can be reduced.

Conclusion

The Q400 is an aircraft that must be used as a high speed aircraft that serves as a compromise between jet-like speeds and turboprop economy. Pushing the airplane to perform to either extreme is a significant deviation from the intended purpose of the aircraft, which leads to inappropriate and poor asset utilization.

Asset utilization seems to be on the increase. The Q400 is deployed on those routes on which a 180 seat jet cannot operate, thereby allowing SpiceJet to grow its roots into untapped markets to feed traffic to the mainline network. It is a gap filler. With more flights a day, the aircraft is being flown to its revenue generating potential. The networks of the two fleets – jet and turboprop are being aligned to cater to a hub and spoke model. However, a good narrow-body jet fleet size is required to allow the airline to make the most of the connectivity offered by its turboprop fleet.