[Omkar]

InterGlobe Enterprises, which backs India's top airline IndiGo, and U.S.-based Archer Aviation (ACHR.N) will launch an all-electric air taxi service in India in 2026 that will be "cost-competitive" with on-road services, the companies said Thursday.

Archer Aviation, backed by the likes of Chrysler-parent Stellantis (STLAM.MI), Boeing (BA.N) and United Airlines (UAL.O), makes electric vertical takeoff and landing (eVTOL) aircraft that have been touted as the future of urban air mobility.

These 'Midnight' e-aircraft can carry four passengers and a pilot for up to 100 miles (roughly 161 kilometers). The service aims to start with 200 aircraft and begin in Delhi, the national capital, Mumbai, the country's financial capital, and Bengaluru, known as India's Silicon Valley. The companies said that a trip that typically takes 60 to 90 minutes by car in Delhi, for example, will take about 7 minutes in an air taxi.

InterGlobe Enterprises, which owns nearly 38% of IndiGo-parent InterGlobe Aviation (INGL.NS) as well as hospitality and logistics businesses, also plans to use the e-aircraft for cargo, logistics, medical, emergency and charter services.

Archer secured a $142 million-deal from the U.S. Air Force in July to provide six Midnight aircraft and said in October it would launch an air taxi service in the UAE. Archer Aviation's shares were up 1.5% in U.S. premarket trading on Thursday, while InterGlobe Aviation's closed up 0.12% ahead of the news.

Source

[V.Narayan]

The point I am struggling with is this - what do these aircraft do that a helicopter does not or cannot. What advantage do they bring over a helicopter which BTW is a proven machine. Just being electric powered might save some costs but I can forsee navigational and route planning challenges, due to tight energy endurance, in case of bad weather even with their short hops. Sao Paulo in Brazil already has helicopters providing this service - infact that one city has a helicopter fleet roughly equal to the whole of India's civilian chopper fleet.

[Red Liner]

Originally Posted by V.Narayan

The point I am struggling with is this - what do these aircraft do that a helicopter does not or cannot. What advantage do they bring over a helicopter which BTW is a proven machine. Just being electric powered might save some costs but I can forsee navigational and route planning challenges, due to tight energy endurance, in case of bad weather even with their short hops. Sao Paulo in Brazil already has helicopters providing this service - infact that one city has a helicopter fleet roughly equal to the whole of India's civilian chopper fleet.

Pretty sure Archer is pumping in investor/shareholder money into this business big time to start flooding the market with their product. India might be their gateway into the south East Asian economies which have huge gridlocks, like Manila, Jakarta, and even Seoul.

[kosjam]

Originally Posted by V.Narayan

The point I am struggling with is this - what do these aircraft do that a helicopter does not or cannot. What advantage do they bring over a helicopter which BTW is a proven machine.

Sir, a tiltrotor type configuration will assist in better efficiency during travel, as the lift is being produced by the wings. In a typical helicopter, the lift in all phases of flight is being produced by the rotor blades.

As a result, the capacity per unit fuel consumed will be lesser in a craft of this design.
Regarding the reliability of a tilt rotor, considering this technology has had upwards of a decade to mature, it should be decent enough (the reliability)

[Jeroen]

Originally Posted by V.Narayan

The point I am struggling with is this - what do these aircraft do that a helicopter does not or cannot? What advantage do they bring over a helicopter which BTW is a proven machine? Just being electric-powered might save some costs but I can foresee navigational and route planning challenges, due to tight energy endurance, in case of bad weather even with their short hops. Sao Paulo in Brazil already has helicopters providing this service - in fact that one city has a helicopter fleet roughly equal to the whole of India's civilian chopper fleet.

I guess you have to start somewhere with getting air transport electrified and this is probably one of the few applications (short routes) that can be served with electrical crafts.

Not sure if they would have a better business case, compared to a helicopter. Are these things subsidised in any way?

I would be very interested to hear about any insights into the certification (FAA and for India) of these machines.

Also wondering about some of the operational aspects. For helicopters and planes, the planning rules are well-known and established. In terms of alternates, minimum fuel you at destination and so on.

I wonder how that works out for these electric crafts. I would imagine that for years to come the regulators are going to be ultra-conservative, till they have sufficient data to allow for less reserves on the batteries.

How does the regulator deal with the ageing of batteries. That is something that is not relevant for a conventional plane. Straight out of the factory, or 20 years old, its range and operational planning parameters remain identical. But we all know that no matter what, battery capacity does come down over time and usage. This means that your effective planning range, alternates and so on, will become less and less as the capacity of the battery diminishes.

At least that is my thinking, I have no idea how the various regulators look at these things. But I would be very interested to hear from members who have some better and more detailed insights into these topics.

Originally Posted by kosjam

Regarding the reliability of a tilt rotor, considering this technology has had upwards of a decade to mature, it should be decent enough (the reliability)

Decent enough doesn't cut it in aviation I am afraid! And these tilt-rotor thingies have a very poor track record. Look at the American Osprey. The aircraft had four crashes and 30 deaths during its initial development. Since entering operational service in 2007 there have been an additional ten crashes and 24 deaths. Two of these ten were on combat operations where the cause was uncertain. The others were due to pilot error or technical problems.

Yes, the tilt-wing brings some advantages, but don't forget about its main disadvantages. The main drawbacks of tilt-wing aircraft are susceptibility to wind gusts in VTOL mode and lower hover efficiency. Also, they don't have autorotation capabilities as every helicopter has.

The Osprey had an additional problem with hovering. Whilst hovering the engines were not cooled enough. Also, the downdraft of a tilting compared to a helicopter is much worse. So it needs much more clean tarmac to touch down.

Also, the tilt mechanism of the wing is very complex. The rotor of the helicopter is a complex thing too, but we have had decades of experience on how to deal with all of that. Rotor and blade failure (which did happen early on) is a thing of the past for helicopters. We are only just starting to get experience with tilt rotors really!

The lower hover efficiency offsets the flight cruise efficiency. The shorter the flight the worse it gets of course. Not sure where the cross-over point is.

I have flown as a passenger on just about anything, from military planes to commercial planes, hovercrafts, seaplanes, and just about all modern helicopters. As a pilot, I have got some experience in flying various planes (and even some helicopters). But I am not going to get into any tilt-rotor plane for the foreseeable future.

Its one of those things that looks good on paper, great in theory, but it simply has not proven itself in practice yet, as far as I am concerned. Both a traditional fixed wing plane and a traditional helicopter are already a huge collection of engineering compromises. We have become very good at it. However, combining the two principles into one craft, increases the complexity and the vast number of engineering compromises required. There is a case to be made for military applications, but I am not so sure about civil applications. We have seen over the last 5-6 decades various attempts, from the Fairy Rotodyne as one of the first to pioneer helicopter/fixed wings to a number of current initiatives. So far, it just has not caught on.

Jeroen

[aviator1101]

Originally Posted by V.Narayan

what do these aircraft do that a helicopter does not or cannot. What advantage do they bring over a helicopter which BTW is a proven machine. Just being electric powered might save some costs but I can forsee navigational and route planning challenges, due to tight energy endurance, in case of bad weather even with their short hops.

I agree with you Sir. There probably are no accruable advantages from aviation point of view. Just imagining the issues like air space management and the load on air traffic controllers are giving me shivers. Of course traffic jams in air are unthinkable. It's not just the machines, but the infrastructure which will take atleast a decade to materialize on ground.

But maybe between the aviation and commercial aspects, the latter are outweighing the former. It's a fantastic opportunity to explore and exploit (if I may say so) after all.

If at all, electric helicopters IMO would be a better option. Why not have something like the Sikorsky Firefly produced in numbers? And these services are for relatively shorter hauls, so e-helicopters should be able to meet the requirements.

Originally Posted by kosjam

Regarding the reliability of a tilt rotor, considering this technology has had upwards of a decade to mature, it should be decent enough (the reliability)

Just a few points for consideration :-

One : the accident/incident record of the only tilt rotor aircraft in service is so poor, that it's reliability in itself is a big question. Most of the accidents have been inconclusively attributed to human error, where aircrew involved were not ab initio trainees but military aviators with 1000s of hours to their credit prior to conversion on type.

Two : Decent enough reliability is not something that will inspire passengers to board an aircraft. They would rather travel the longer way and live to see another day. Even FAA has not yet issued air worthiness certificate to the tilt rotor configuration (Augusta Westland 609) for commercial use.

Three : VTOL/STOL and higher forward speed are the only major advantages here but the cons outweigh the pros by miles. To list a few

• Engine failure on any one side is likely to cause thrust imbalance in hover phase
• The transition phase from vertical to horizontal flight is aerodynamically unstable
• Emergency recovery procedures of a helicopter like autorotation are not applicable once in forward flight
• Failure of critical components like cross link drive mechanism and engine pylon tilting mechanism.

Long way to go actually.

Hope these issues are sorted out prior to commercialization and a joke not made out of Flight Safety.

[kosjam]

Originally Posted by Jeroen

Decent enough doesn't cut it in aviation I am afraid! And these tilt-rotor thingies have a very poor track record.
Jeroen

Originally Posted by aviator1101

Two : Decent enough reliability is not something that will inspire passengers to board an aircraft. They would rather travel the longer way and live to see another day. Even FAA has not yet issued air worthiness certificate to the tilt rotor configuration (Augusta Westland 609) for commercial use.

I guess it was a poor choice of words on my part. What I meant was that considering aviation regulators are giving them licences, in multiple countries, the reliability must be good enough for the company to have gotten the go ahead to launch the services. There must have been rigorous testing and validation trials carried out before they would consider allowing commercial operations. When I said "decent" what I really meant was decent on the benchmarks of aviation standards.

Originally Posted by Jeroen

Whilst hovering the engines were not cooled enough.

Also, the tilt mechanism of the wing is very complex. The rotor of the helicopter is a complex thing too, but we have had decades of experience on how to deal with all of that. Rotor and blade failure (which did happen early on) is a thing of the past for helicopters. We are only just starting to get experience with tilt rotors really!

Jeroen

Regarding cutting edge technology, it is many times not visible to us common folk the vision of the people who bring such ideas to reality. The fact that they have reached a level where they can realistically offer rides in the not too distant future would certainly point to such a scenario.

The developmental pains that the V-22 went through would certainly have been studied and analysed by the designers prior to having gone to the design table. Also, on the grounds that it is an electric plane, the complex mechanicals of a traditional ICE engined tilt rotor might be irrelevant, considering the motor might just turn with the propeller itself.

Finally, regarding the battery, most high quality battery packs have shown marginal to low degradation in multiple use cases even as far as 4-5 years, and with a high quality BMS, this issue should not be a serious one in my honest opinion.

I for one am quite positive about such high tech solutions to mobility and look forward to its success.

[V.Narayan]

Jeroen and Aviator 1101,
Thank you for making several excellent points of concern with regard to this aircraft. I second each of those points with a vengenance.

Kosjam,
Thank you for your posts. Just because DGCA or FAA have certified something so new and breaking ground doesn't mean much given that the civilian rule book on these is yet to be written and these regulators have less to go by. DGCA I know simply has no competence or experience in dealing with fixed wing vertical take-off and landing {VTOL}, none whatsoever.

All,
As any Harrier pilot would attest the vertical landing and vertical take-off* are fraught with risk not only of pilot error despite all the training but also the inherent instability of the aircraft. In the case of Archer's machine it is literally balancing {in vertical mode} on six thin columns of vertical thrust all in one line and not spread out at the four extremities!!!

Also, at Vertical take-off the MTOW to thrust ratio is at best 1:1. Given the weight of batteries that leave limited room for payload. Which brings me to my first question - what does this machine do that a helicopter cannot do better. And if short hops are the market then the extra speed of a fixed wing does not matter. It is being focused on short hops not because of an economic benefit but because of not being capable of anything better.

The energy density of batteries today and the forseeable future is so low compared to aviation fuel that the only electric powered aircraft I can forsee are conventional take off and landing ones with super efficient wings for lift at low speeds and a highly streamlined fuselage for short commuter hops - like the Israeli Alice below. The other application I foresee is that of a large cargo airliner with ample volume and weight carrying capacity to accommodate cryogenic hydrogen tanks and then run on hydrogen fuel with say propfan engines. To be meaningful this aircraft is possibily in the size range of large wide bodies.

My thread of electric & hydrogen powered aircraft below.
https://www.team-bhp.com/forum/comme...ircraft-3.html (Electric & hydrogen powered aircraft)

* Though capable of VTOL the Harrier rarely does a vertical takeoff though it often if not almost always does a vertical landing.

[Jeroen]

As it stands, the Archer has not been certified by the FAA or any other regulator yet. The timeline according to their own website is sometime 2024.

They only started the certification process in 2021. All flight testing to be done in 2024.
I am not sure how realistic such a timeline is. FAA certification tends to take 6-10 years.
Thinking you will start flight testing and having your FAA certificate within a year of flight testing is, my opinion, simply not realistic. How many new planes on the market have achieved that?

The FAA type certificate will allow the manufacturer to build only a very limited number of planes. In order to start mass producing the manufacturer needs to get the factory and it’s processes certified as well.

These guys, going by earlier promises are behind the curve when it comes to certification.

If you are interested in this topic, here is a good explanation by Wisk, a competitor of these guys, who are far more experience and never achieved FAA type certification in under 8 years.

https://wisk.aero/news/blog/certifyi...ous-air-taxis/

I wrote about the PALV, a much more traditional aircraft, which is taking close to 10 years for its FAA certification. https://www.team-bhp.com/forum/inter...lying-car.html (A visit to the PAL-V Factory | A close look at their Flying Car)

Earlier this week I received an invitation to come and visit their factory once again in a few weeks time.

There is also the matter of a billion dollar law suit back and forth with one of their competitors. Makes for a huge distraction of management.

https://www.flyingmag.com/wisk-v-arc...ecret-lawsuit/

Jeroen