IndiGo and the A321 XLR
IndiGo is an Indian low cost carrier (LCC) than commenced operations in 2006. Its growth could be described as meteoric, building a fleet of nearly 400 aircraft in less than two decades. While nominally a LCC its growth is evolving IndiGo into a hybrid carrier.
In recent years it’s moved away typical LCC strategies by adding small turboprop aircraft (thereby moving away from a single fleet type), starting dedicated freighter services and rolling short haul business class. In its most ambitious move yet it has announced plans for a fully fledged long haul operation with an order for 30x A350-900 aircraft (deliveries from 2027).
Of more contemporary interest is their order for the A321 XLR, with 69 aircraft due for delivery from next year. There has been significant discussion and speculation where IndiGo will fly these aircraft.Some have hypothesised that IndiGo could fly to London and Amsterdam, as both these destinations are well within the 4700nm range that Airbus publicises in its marketing materials. By this reckoning, they could reach anywhere in Europe, nearly anywhere in Africa, and the western half of Australia.
As we noted in our most recent assessment of the XLR (see below), the 4700nm nominal range isn’t a useful benchmark as its actual range is sensitive to the configuration that the airline plans to use. Once adapted to their network strategy and operational model, the range envelop might be significantly smaller.
A321XLR (finally) enters into service
In practice we see Qantas equipping the XLR with 197 or 200 seats and planning to utilise it on domestic and short regional services. Meanwhile Iberia are flying their XLR will more passengers and shorter routes than SAS flies their A321neo LRs! So let’s have a look at how IndioGo might deploy the XLR!
The opportunity for IndiGo
The XLR presents an interesting opportunity for IndiGo. It doesn’t offer them a larger aircraft considering they already operate more than 100x A321neo. It does offer them more range, but how much?
The 4700nm nominal range isn’t estimated with a full payload but rather with a full fuel load. In practice, every aircraft has a trade-off between payload and fuel. We considered this in the previous analysis, but let’s have a quick refresher:
The XLR has a maximum fuel capacity of 32t and a maximum payload of 26t. This combined would amount to 58t.
The aircraft’s empty weight (OEW) is 50t and its Maximum Takeoff Weight (MTOW) is 101t (at present, it is only certified for 97t but it’s expected to have an option for 101t in the coming months).
At full payload and fuel capacity, the takeoff weight (TOW) would be 108t (OEW + fuel + payload), far exceeding the MTOW of 101t).
So some combination of fuel and/or payload needs to be reduced by 7t. An alternative way of looking at this is that carrying maximum fuel limits the payload 19t (27% reduction), while maximum payload only allows 25t of fuel (22% reduction). Less payload means fewer passengers (we can leave cargo out of it for the time being), while less fuel means a shorter range.
So if IndiGo were going to maximise the aircraft’s range it would significantly limit its payload meaning a relatively small passenger load. This raises an important question: what passenger configuration do IndiGo plan to install on their XLR?
Configuration and payload: what will IndiGo’s XLRs look like?
ike many LCCs IndiGo started life with high density economy class configurations. For example, the majority of its A320neo and A321neo seat 186 and 232 passengers in all economy layouts. Its recently announced short haul business class on some of their A321neo has a 12/208 split between business and economy class, reducing the total seat count from 232 to 220 passengers.
When commentators speculate where IndiGo might fly their XLRs they often ignore the the implications of the configuration that IndiGo will utilise that defines the payload and range. We have no idea what the XLR’s configuration will look like. Rather than speculate on IndiGo’s potential configuration, let’s consider several potential routes and determine the potential payload and see what this would mean for passenger loads.
Delhi-London
London is the largest long haul market to/from India, but it’s also one of the furthest away of the speculated destinations. DEL-LGW is 4183nm via the great circle route, far less than the XLR’s 4700nm nominal range.
When conducting a flight planning exercise the distance isn’t important, rather calculations are affected by flying time. Air India’s B787 and A350s typically take between 8.5 and 9.25 hours on the westbound leg, and 7.5 to 8 hours on the return eastbound. As westbound is longer, let’s work with that since this is the functional constraint. These flight times are already inflated due to airspace restrictions (e.g. Ukraine), however the XLR will take a little longer since it cruises at a lower speed than B787s and A350s!
Assuming a flying time of 9:10, the aircraft will require approximately 27t of fuel. We also need to add additional fuel for taxing, contingencies, alternate destination and final reserve. An additional 4t should be sufficient for an extra 90 minutes utilising LTN as the alternate. The total fuel load will be about 31t and is just about the aircraft’s capacity. We’ve rounded to the nearest 1t but in practice these calculations are more precise.
Given the fuel load and assuming that that full 101t MTOW can be utilised, the payload will be limited to 20t. So how many passengers can 20t carry? This depends on the mix of passengers and bags. If the flight carries more women than men, or more children than adults this number will decline, but a bias towards men and adults increases this. Our Indian friends tell us that flights to/from India are typically carry heavy baggage loads, increasing the typical weight per passenger! Making matters worse is that this also includes crew.
Regulators in most countries give airlines direction on typical weights to assume for flight planning purposes. For example, in Australia, CASA prescribes a standard weight for an adult male of 82kg. With a typical 23kg checked baggage allowance and 7k carry-on (latter is also prescribed), the total weight is 110kg. Meanwhile, an adolescent female is estimated at 55kg, thus 85kg with standard baggage.
If we assume a planeload of 13 to 16 year old girls, then the 20t payload could carry 235 passengers and crew, but that’s unrealistic. Assuming an average weight of 100kg, this declines to 200, while 110kg each would mean 180. As we can see, this is a significant difference. Assuming a crew contingent of 8, this would mean a passenger load between the low 170s and 190s.
This also ignores day-to-day variations in flight operations. For example, let’s imagine poor weather at destination requiring additional hold fuel or use of an alternate further away. Utilising MAN instead of LTN would limit the passenger load by another 10.
A little closer to home: Delhi-Frankfurt
Let’s rather consider a slightly shorter route, say DEL-FRA that at 3311nm, 324nm shorter than DEL-LGW. With a westbound flying time of 8:40 requiring 25t of fuel plus 4t for taxi, contingencies, alternate destination and final reserve. This would allow a payload of 22t. The additional 2t would allow between 200 and 220 passengers and crew depending on the average weight. Assuming a crew contingent of 8, this would mean a passenger load between the low 190s and 210s, compared to between low 170s and 190s to London.
The XLR’s configuration would need to be between 190 and 210 seats to operate DEL-FRA, and between 170 and 190 seats to operate DEL-LGW. IndiGo’s A321neo with business class seats 220 passenger. That’s not to say that IndiGo will utilise this configuration on the XLR, but we can view this at the upper end.
Utilising a lie flat business seat or a larger seat pitch in economy class would reduce the passenger count further. But let’s be frank, it’s unlikely that IndiGo are going to be installing a relatively low density cabin like Iberia’s 182 passengers (14 business and 168 economy class) that would make DEL-LGW viable. DEL-FRA at 3311nm looks more reasonable, bringing into focus the very big gap between the practical range for IndiGo XLR’s and the aircraft’s nominal range!
But should we view 3300nm as a hard limit? Flying further will require a lower cabin density but that’s unlikely to align with Indigo’s business model. But what stops IndiGo installing more lie flat business class seats?
Armchair CEOs don’t live in reality
For a LCC to sell cheap tickets they need to reduce costs to ensure it can generate sufficient profit to justify the investment in expensive aircraft. There’s always a lot of talk about how LCC reduce costs relative to incumbents and competitors. Single fleeting, rapid turnarounds, obtuse scheduling, remote airports and limiting overnighting of crew at outstations are all methods that have been implemented to different degrees at many LCCs. However, increasing passenger density is the most common and probably most important!
Many of the operational costs on a given flight are fixed. Fewer passengers on the same aircraft doesn’t mean the aircraft, maintenance and crew cost less. While a lighter passenger load will burn less fuel this isn’t linear, thus a 10% reduction in passengers reduces fuel burn by less than 10%. Other costs may be linear, but the aircraft, crew and fuel are overwhelmingly the largest cost centres for airlines. All else being held constant, fewer passengers on the aircraft results in a higher unit cost (cost per available seat kilometer) for a given route.
Full service carriers are willing to tolerate higher unit costs as they plan to make it up through higher unit revenues and yields. While IndiGo is evolving into a hybrid carrier, their continued success is dependent on maintaining their relative cost advantage over incumbent full service carriers. This is their comparative advantage and frames their broader strategy. Applying it to the XLR, it appears unlikely that they’re going to roll-out a 182 passenger XLR just to fly to London, increasing unit costs across a broad chunk of their fleet and forcing them to seek higher prices.
It’s not all about Delhi and Europe
This analysis focussed on Delhi but that is a didactic example. The world doesn’t revolve around Delhi, however the same principles apply to flight planning from other Indian cities. But Delhi is relatively closer to Europe than many other Indian cities. For example, routes into Europe from Chennai would be more limited in scope compared to Delhi. But what Chennai loses to Europe, it gains to other destinations in Africa and Australia.
But where does it leave the XLR? IndiGo have 69 aircraft on order and that’s a lot of flying time to deploy. While everyone has focused heavily on Europe we also need to consider the counterfactual which is the practical range of IndiGo’s A321neo and A320neo.
A321neo
DEL-SIN 2,241nm
HYD-JED 2,236nm
CCJ-JED 2,207nm
BOM-SIN 2,116nm
DEL-HKG 2,026nm
A320neo
BLR-DPS 2,592nm
BOM-CGK 2,504nm
BOM-NBO 2,447nm
BLR-MRU 2,331nm
BLR-JED 2,262nmAt present, Indigo’s longest A321neo routes are in the range of 2200nm, while its A320neo stretches its legs to just above 2500nm. However, it’s longest A320neo route (BLR-DPS) is likely operating with some payload restrictions, and even BOM-NBO might be running into some. The A321neo on HYD-JED is also operating with some sizeable payload restrictions. If we consider 2300nm a rule of thumb for the current fleet operating without payload restrictions we can see the opportunities the XLR will open up for IndiGo.
Firstly, it will allow a range of existing routes presently operated with payload restrictions (i.e. up to 2600nm) to be operated with with higher loads or with bigger aircraft. For example, HYD-JED would shift from the A321neo to XLR and operate without payload restrictions, while BLR-DPS could shift from the A320neo to XLR to allow a larger aircraft on an otherwise frequency limited route.
Secondly, it will also open a range of other Asian destinations that are presently out of range or marginal with the existing fleet. For example, this could open up Korea and Japan from Delhi, or Perth from Chennai.
For the last time, it’s not just about Europe
IndiGo is another airline that shows how we are easily distracted by the XLR’s nominal range. Instead the practical range is affected by the aircraft’s configuration that is ultimately a function of the airline’s business model and strategy. The key message when considering where IndiGo might fly the aircraft is also to consider the counterfactual.
It’s not just new routes, but also existing routes might be better served with the XLR. There are a wide range of routes that are presently operated with payload restrictions that may benefit from the XLR’s capability. Alternatively, there are routes that are presently served by the smaller A320neo that IndiGo would prefer to serve with the larger A321neo but are limited by the performance of the baseline version. This has been widely ignored in the discourse that has focused on new destinations, particularly in Europe.
There are other constraints to also consider. Notably, the final specifications of the aircraft is likely to differ with MTOW coming in slightly lower than 101t. It’s unlikely to affect the overall strategy and there is also no reason to expect that IndiGo would require the maximum payload on most trips. This is likely why we haven’t seen the updated payload-range chart for the 101t MTOW version of the XLR since the RCT was redesigned.
But it still leaves several open questions: what product will IndiGo install including what type of business class seat, and what will the balance between business and economy be?
More business seats mean fewer economy seats, with a greater than one-for-one tradeoff, reducing total passenger count, while a different business class product more suited to longer flights would also reduce passenger count.
These questions aren’t static. Sometimes AvGeeks unreasonably expect airlines to have a well-designed tactical plan including how and where they will operate a new aircraft well in advance of delivery. In practice, orders align to a broader strategy with the tactical plan evolving closer to the time. Just too much can change between order and delivery, including economic and geopolitical conditions, and even the aircraft’s performance.
From what we know, we expect the XLR’s deployment to be more pragmatic and less fanciful. We should expect less London and more Jeddah and Seoul! But there’s a caveat: in the same way payload restricted flights to Bali may be a strategy to open up the destination and utilise frequencies in anticipation of a more capable aircraft the same might also be part of the XLR’s initial plan!
It’s not a crazy proposition to introduce the XLR on Delhi-London - even with severe payload restrictions - as a temporary market building exercise in anticipation of the A350 in 2027. Aren’t we contradicting ourselves? Absolutely! But it’s important to distinguish between sustainable routes which Delhi-London won’t be on the XLR and a calculated risk to build a market. And there are far larger risks doing this to London than Bali, but that’s a discussion for another time!
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