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-   -   Single Aisle Twins performance at KASE - Aspen (https://www.pprune.org/tech-log/656633-single-aisle-twins-performance-kase-aspen.html)

20driver 31st Dec 2023 14:37

Single Aisle Twins performance at KASE - Aspen
 
I live in Snomass CO and frequent Aspen airport. Aspen is going through a lot of angst about upgrading the airport to a full design group III. Right now there is a limit on runway/taxiway separation. Currently the commercial service is on RJ700 models flown by Skywest code shares. Skywest is shifting their fleet to the EMB 175 series. .
There is lot of angst about going "green" here. I have looked up numbers for the 737-Max8 which uses about half the fuel and is quieter and produces half the CO2 of an RJ
The EMB 175 seems to limited for operations here and overall does not seem a great performer.
The other alternate mentioned is the A220 but right now that is pretty much Delta - which is operating the planes on mainline contracts.
What I want to establish is which of the recent 737 or A319/320 models could operate here. It seems the worse case is the summer due to temperatures and altitude. United and Southwest are the dominant airlines in the region and they tend to be 737.
ASE is a challenging landing. ASE is 8000 feet long at 7680 feel elevation. It is basically one way in and out. I was told by a Skywest training captain the the max weight single engine escape only guarantees 50 feet of ground clearance which sounds pretty scary to me. Only a small number of Skywest crews are allowed to operate to Aspen. I think that is a Skywest rule, not an FAA rule.
Another issue is ASE does not have WAAS which several nearby airports do. It seems unclear but it appears Skywest RJ's are not WAAS enabled.
I was told there is no STC to provide WAAS in the RJ but cannot confirm this.
Certainly for mountain operations in the winter WAAS would be nice. I suspect there are a lot of avionics upgrades not available to the RJ
We have a local gadfly who has many in the Valley convinced that there are all sorts of green electric planes ready to fly so we should not upgrade the airport at all.
Any help or suggestions would be appreciated.
​​​​​​​Thanks



Check Airman 31st Dec 2023 15:49

I’d guess the A319 may be able to handle it. They go to EYW, which is similar when you correct for altitude.

SWBKCB 31st Dec 2023 15:59


We have a local gadfly who has many in the Valley convinced that there are all sorts of green electric planes ready to fly so we should not upgrade the airport at all.
Asking for some facts normally sorts ths type out.

In service dates, capacity, that sort of thing :O

20driver 31st Dec 2023 17:28

The guy is our local Don Quixote - you can see his rambling at Aspen Fly Right website.
https://aspenflyright.org/wp-content..._25Dec2023.pdf

He is immune to facts.

galaxy flyer 31st Dec 2023 20:00


Originally Posted by 20driver (Post 11565226)
The guy is our local Don Quixote - you can see his rambling at Aspen Fly Right website.
https://aspenflyright.org/wp-content..._25Dec2023.pdf

He is immune to facts.

it certainly is immune.

West Coast 11th Feb 2024 05:03


Originally Posted by 20driver (Post 11565147)
I live in Snomass CO and frequent Aspen airport. Aspen is going through a lot of angst about upgrading the airport to a full design group III. Right now there is a limit on runway/taxiway separation. Currently the commercial service is on RJ700 models flown by Skywest code shares. Skywest is shifting their fleet to the EMB 175 series. .
There is lot of angst about going "green" here. I have looked up numbers for the 737-Max8 which uses about half the fuel and is quieter and produces half the CO2 of an RJ
The EMB 175 seems to limited for operations here and overall does not seem a great performer.
The other alternate mentioned is the A220 but right now that is pretty much Delta - which is operating the planes on mainline contracts.
What I want to establish is which of the recent 737 or A319/320 models could operate here. It seems the worse case is the summer due to temperatures and altitude. United and Southwest are the dominant airlines in the region and they tend to be 737.
ASE is a challenging landing. ASE is 8000 feet long at 7680 feel elevation. It is basically one way in and out. I was told by a Skywest training captain the the max weight single engine escape only guarantees 50 feet of ground clearance which sounds pretty scary to me. Only a small number of Skywest crews are allowed to operate to Aspen. I think that is a Skywest rule, not an FAA rule.
Another issue is ASE does not have WAAS which several nearby airports do. It seems unclear but it appears Skywest RJ's are not WAAS enabled.
I was told there is no STC to provide WAAS in the RJ but cannot confirm this.
Certainly for mountain operations in the winter WAAS would be nice. I suspect there are a lot of avionics upgrades not available to the RJ
We have a local gadfly who has many in the Valley convinced that there are all sorts of green electric planes ready to fly so we should not upgrade the airport at all.
Any help or suggestions would be appreciated.
Thanks

The issue isn’t being able to fly a particular approach, it’s the ability of larger aircraft to fly an extraction should they not be able to land close in. A study from about 3-4 years ago suggested with larger aircraft that there might be a point where the aircraft is committed to landing, a scary prospect given the unpredictable winds and opposite direction traffic.

As to upgrading to achieve WAAS capability, it would take changing out the Collins 4200 FMS and a number of LRU boxes to achieve that. No business case can be made for an aircraft that close to being replaced in ASE.

By what measure does a 737 Max 8 use half the fuel of a 700? CASM? Certainly isn’t total fuel burn.

West Coast 11th Feb 2024 05:04


Originally Posted by Check Airman (Post 11565169)
I’d guess the A319 may be able to handle it. They go to EYW, which is similar when you correct for altitude.

This isn’t a runway length concern.

AerocatS2A 11th Feb 2024 17:38


I was told by a Skywest training captain the the max weight single engine escape only guarantees 50 feet of ground clearance which sounds pretty scary to me.
This is the case for all single engine escape paths. It’s a procedure design / performance requirement.

20driver 11th Feb 2024 21:43

West Coast
Thanks for the reply.
Re the fuel figure - I got it from https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft
They have the data nicely tabulated. The numbers they use seem to check out with others I have found.
For a 737-Max 8 they have a per seat figure of 2.77L/100 Km for 500 mile leg
For the RJ700 the same number is 4.36 L /km for 500 mile leg
The table also shows a 737-Max 7 which is not in service - so not sure where that came from .
American and United fly A-319 and B 737-700 from Eagle which is also a special use airport.

ASE is going to run of out jets for commercial service. There is only Embraer selling Regional jets and their volume is pretty low. The E-175 is not a great performer but that is what Skywest is replacing the RJ with.
What is interesting is in the ski towns in the region , Eagle Vail, Jackson, Steamboat , Montrose is most of the flying is being done by the mainline iSingle Aisle Twins and the regional jet flying is shrinking. I am guessing the big factor is regionals are having to step up their pay substantially and economies of scale are making the bigger planes a better deal.

I did find a study down for the Airport that showed the 737-700 was marginal for the missed approach in the summer.



WHBM 11th Feb 2024 23:06


Originally Posted by 20driver (Post 11565147)
The EMB 175 seems to limited for operations here and overall does not seem a great performer.
The other alternate mentioned is the A220 but right now that is pretty much Delta - which is operating the planes on mainline contracts.
What I want to establish is which of the recent 737 or A319/320 models could operate here. It seems the worse case is the summer due to temperatures and altitude. United and Southwest are the dominant airlines in the region and they tend to be 737.
ASE is a challenging landing. ASE is 8000 feet long at 7680 feel elevation. It is basically one way in and out. I was told by a Skywest training captain the the max weight single engine escape only guarantees 50 feet of ground clearance which sounds pretty scary to me. Only a small number of Skywest crews are allowed to operate to Aspen.

Here at London City the Embraer has been a longstanding principal operation, the shorter 170s have been sold (to the USA !), but the E190 is dominant. They operate where it is impossible for the A319/737 to do so, these latter not being allowed (the A221 is but not the A223). Time was, before the Embraers came along, that the 146 was the "only possible" jet here, and I think you may recall the same was said about that type at Aspen too.

This airport does not have the elevation, but does have just a 4,500 foot runway, and the Embraer is often off in less than half that, with a very considerable angle of climb. London City has comparable challenges, it's a Captain Only landing, needs special training, and has significant engine-out limit climbout restrictions in its inner city location, due to nearby tall structures, which have caused other types not to be allowed but the Embraer is fine. Fully loaded lights with the Embraer take off to as far away as the Greek islands (and have quite a bit to spare - we took this, there was a thunderstorm over the island airport, and we held for half an hour, whereas an Italian charter 737 coming in from half the distance at the same time had insufficient fuel to do so and diverted to Athens). So I think you will find performance is fine. .

20driver 12th Feb 2024 01:44

Thanks for the info WHBM
Right now the issue at Aspen is they have a 96 ft wing span limitation so the E2 series will not work. This 96 ft limit is a non conforming feature of ASE due to a less than design separation of the taxiway and runway. The FAA wants the limitation gone and will not approve Federal funds without the airport layout becoming compliant to DGIII.
That leaves only the E170 as the only passenger jet in production that meets this limitation. The local bun fight is about making the changes required.
The BAE 146 was before my time but it was the Aspen workhorse for years along with the DHC-8.
If the airport becomes DG III compliant it opens up the E2 series which looks like a good choice. Right now the airport is getting painted into a corner.

ASE has a huge amount of private jet traffic and the 96 ft limit has little impact there, only a few models are excluded. It is the commercial service that is impacted.

MarkerInbound 12th Feb 2024 01:47

Comparing seat mile fuel burn only works if the airplane is full. The chart shows a CRJ 700 can carry 70 passengers. For the Max 8 they show 166 passengers. If only 70 folks show up for the flight you’ll be burning a bunch more fuel per passenger. The column next to the seat mile one that shows kg per km or pounds for mile will give a better idea how much it takes to go a certain distance.

20driver 12th Feb 2024 03:17

Thanks Marker Inbound That is a relevant observation.
In the case of ASE most of the flights are duplicated. United has 9 flights a day to Denver. (Which is 200 miles away - so the majority of passengers are transiting Denver, Denver residents would just drive.)
There are two Delta fliight to ATL within 90 minutes of each other!
Likewise 2+ daily to Chicago, SFO and Houston on United. 4x daily on American to DFW.
It is very wasteful - if the airport could accept larger planes there would be a significant reduction in flights.
We are pretty much all tourist traffic so people are more flexible than business traffic.
If we had better range options there would be fewer people transiting through Denver and would gladly accept a non stop.
I suspect that overall flights would be reduced by close to half.
That is what is happening at similar airports in the area.
The irony is the same people who oppose the reconfiguration of the airport also identify as "greens" - but are pushing to keep the fuel inefficient airplanes , RJ70 and E170 as the only options.
There is a lot of emotion involved here and rational thought is not what wins these arguments. There is a big concern that bigger planes will mean more visitors.

West Coast 12th Feb 2024 04:36

Much of that volume is seasonal, dropping off or eliminated in the mud seasons. Passengers also place value in having multiple choices of flights through out the day.

WHBM 12th Feb 2024 11:17


Originally Posted by 20driver (Post 11595206)
The irony is the same people who oppose the reconfiguration of the airport also identify as "greens" - but are pushing to keep the fuel inefficient airplanes , RJ70 and E170 as the only options.
.

That's actually quite common, these are people who get interest in life out of pushing others around, especially those who earn more than they do. Don't expect logic and consistency of reasoned argument, or understanding, because that is not what they are all about. Very often they are the recently retired, looking for something to do. It's quite common that of say 1,000 noise complaints at an airport, 500 (or even 900) will be from one individual who is making a career out of it.

The aspects of taxyway closeness to the runway, and wingspan limits, are also issues at London City, the latter in part because of the gate spacing. It's even an issue that the Embraer E190 can make ground manoeuvres that the A221 cannot, the latter having to taxy out on the runway as not able to use the older, west end taxyway.

Obama57 1st Mar 2024 15:20

G-550, we were test flying the LOC (or possibly a VOR APP) years ago in the sim and could never meet our stabilized approach criteria. With full flaps and gear, airspeed increased 25-30 Kts above Vref going downhill and unspooled. Doesn’t look like the GPS - F is any different re the G/S angle. Can’t imagine the 320 at Vref, 140, could meet any stabilized approach criteria.


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