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Foxcotte
1st Feb 2018, 11:41
Would anyone operating a Challenger consider putting one in and out of an airfield with the following specs:
- 7000' altitude
- ISA +15
- 200' gradient threshold to threshold (on a mountain slope)
- 1600 metres long
- tarmac
- no nav aids/uncontrolled.

Trying to settle a bar argument..... Thanks

atakacs
1st Feb 2018, 11:47
Well one big item missing is obviously the load? Minimum fuel / no pax?

Jet Jockey A4
1st Feb 2018, 12:13
If we are talking about a 3.8% runway slope, then you have your answer right there, NO.

Without the AFM's manual for performance calculations, the actual load (fuel/cargo/pax), it seems to me that for a 1660 metre/5250 foot runway at 7000' and ISA +15C, the runway seems a bit short.

Dont worry
1st Feb 2018, 12:27
Just post the airport, you are talking about and i will give you a performance calculation if it works out or not.
If you dont want to post it here, just send me a PM

Foxcotte
1st Feb 2018, 13:47
I'm not being coy - its a private airstrip in Africa and the bar talk is that the owner put a Challenger in there. I don't know the Challenger at all but I do know a Bravo and I'd be double-thinking the Bravo - hence the argument. Its not an airstrip that has a ICAO designation either - its still being upgraded by the new owner (who currently uses a PC12) so not even on Google earth but there's no way I think he'd get a Challenger in there... light weight or not. The nearest proper airport with facilities and fuel would be 90 NM away, so it could be done with minimum fuel but even so....???

His dudeness
1st Feb 2018, 14:55
There is Challengers and Challengers. The 300 is a different beast altogether rwy performance wise. IIRC no numbers for a slope bigger than 2 in the big old manual.

Plus: any required first/second segment climb gradients (obstacles...)

Dont worry
1st Feb 2018, 15:12
If you talk about the 604/605 it is limited to +-2% Slope.
Thats a limitation so everything above is a no go anyway.
PM me your email and i can send you some Manuals for the 604/605 and the 300

Jet Jockey A4
1st Feb 2018, 15:14
Like I said in my initial post if that runway as a 3.8% slope you are out of the limits of this aircraft as per the AFM (+/- 2% slope) so it would not only be illegal but immoral to operate a Challenger there.

Assuming the runway was within allowable AFM limits then a quick look at the numbers from a 604 QRH gives us the following info...

CONDITIONS:

- ISA +15*C at 7000' = 16*C.

- Runway length is 1600 metres or 5250 feet.

- At 6000' airport elevation and 10*C a 36,000# aircraft would require 5190' of runway.

- At 6000' airport elevation and 20*C a 34,000# aircraft would require 4950' of runway.

- At 8000' airport elevation and 10*C a 32,000# aircraft would require 5010' of runway.

- At 8000' airport elevation and 20*C a 32,000# aircraft would require 5290' of runway (40 feet more than the runway length).

Using the actual AFM to fine tweak the numbers for a 7000' airport elevation would give you better numbers but extrapolating the above numbers for 7000' airport at ISA +15, you could possibly takeoff with a +/- 33,500lbs GTOW with a 604 type Challenger.

BOW for this type of aircraft can be between 27,500 and 28,000 pounds depending on completion. So assuming a 34,000# GTWO that leaves you a payload of about 5500 to 6000 lbs.

For planing purpose you can plan on a 3000 to 3500 lbs fuel burn for the first hour. So yes you could possibly operate a Challenger (604/605/650) there but you are not going far.

Just for the exercise because I was curious, I ran numbers for the Global under the same conditions and the Global could have a payload of 20,000 lbs out of that airport compared to the possible 6000 lbs for a 604.

galaxy flyer
1st Feb 2018, 15:53
The Global will always do that in a comparison with any Challenger or Lear 45/75.

GF

GlenQuagmire
2nd Feb 2018, 03:58
Oh god, dont say that... some idiot will base one there and I bet I end up working on it..

CL300
2nd Feb 2018, 07:22
Oh god, dont say that... some idiot will base one there and I bet I end up working on it..

:):):):):):):):):)