This thread is a spinoff from 707 conversion from Jet to Fan engines as promised...
The question was whether aircraft fitted with these early engines experienced a reduction in MTOW at high airports like Bogota, Quto, La Paz.
Bogota & Quito are about 2,600m (~ 8,500ft) ASL. La Paz a fair bit more.
Piston engine performance was probably afected more.
Even today widebodies (747s and 340s) tankup in Caracas before a transatlantic hop rather than in Bogota. Not sure if this has more to do with the plane landing in Caracas 1.5 hrs after departing Bogota rather than a limitation in MTOF ( i.e. MLW is the issue)
By corollary from the previous thread it would appear that pure jets would fare better at high altitude airports than fans.
BelArgUSA
18th Feb 2009, 10:13
Hola b377 -
xxx
Unfortunately, my PanAm 707/720 manuals, and performance section are all but history, either recycled as paper, or given to pilot wannabees. I operated quite frequently to Bogota, Quito... and La Paz, in the 1969-1973 period, either as F/E or F/O on the 707/720.
xxx
Actually, La Paz (LPB) was the only airport presenting an acute performance problem, because the altitude of the airport, at 13,400 ft. We had a couple of 720B approved and modified for operations at that airport. The regular 707 and 720 would have a cabin altitude warning when cabin altitude exceeded 10,000 feet... and the oxygen masks would drop in the passenger cabin should the altitude exceed 14,000 ft. (+/- 500 feet...!). Besides, the takeoff/landing limits for a regular 707/720 was 10,000 ft PA, so these 720B airplanes had a 15,000 ft PA limit waiver for LPB operations. I do not recall 707-321B/C so modified.
xxx
So PanAm had a few 720B modified for silencing the cabin warning, and the barometric/electrical release of oxygen masks. I only recall operating 2 or 3 times from LPB with the 720B, the 20 flaps takeoff (could not use 30 flaps) and landing with 40 flaps (could not use 50 flaps) as requirements. Yet we operated direct from LPB to MIA, with a decent payload. We also took off unpressurized, no bleeds. I also recall that we were supposed to use our oxygen masks for 30 minutes before takeoff, was a FAA requirement, not observed by other non-USA air carriers. South American flight crews have turbocharged lungs...!
xxx
I do not know what they did with the 727 operating in LPB. Never talked much with LAB flight crews about what engines they had. I recall that Mexicana operated there too, but with 727-200s with JT8D-17R engines and JATO emergency power available.
xxx
As far as operating Quito, Bogota and Cali, in the 8,000 ft PA bracket, with the 747, it does not present a problem, yet the maximum T/O weights are reduced. I have a friend, who was Avianca training captain, who gave me a familiarization flight on a MD-80 jump seat to Bogota and Cali and showed me the "tricks of the trade" in case of engine failure operating to/from these places, and the little "hills" around these airports. Having a "SID" is fine, but the boys from Avianca sure know where to go and to turn.
xxx
I recall the old (erroneous) attitude of many North Americans and/or Europeans who say "going to South America... fly only with American (or European) well trained pilots and airlines"... If you value your life, I personally would recommend the "local pilots and airlines" to get you "in or out" safely in these areas. Shall I mention the nice smiling cabin service... Flying to such places should not be "seniority" but "experience and familiarity"... and unfortunately, understand Spanish accented ATCOs. I have to admit, I often used Spanish for communications.
xxx
Just my (educated) opinion... Ready for "flak"...
My rocking chair can handle that.
:8
Happy contrails
No flack from me my friend - I lived in Bogota until 1979 our house directly in line ( mas o menos) with El Dorado 13/31 runway. So quite familiar with early jet and piston traffic over the house since 1966.
as a kid travelled a lot in two DC3s ( opeated by COLPET, US & Col pilots) between Bogota, Barranquilla and Tibu (near Cucuta) HQ of COLPET and SAGOC taken over by Ecopetrol since 1980s.
I fully undersatnd the 'familiarity' issue not wishing to mention the AA 965 incident near Cali in Dec 1995. The Aerocondor Starliner Dec 1966 accident at el Dorado is a different matter.
E. k. Gann knew all about flight conditions in that neck of the woods
in The High and the Mighty .
cordial saludo
Note the (baro) altimeter reading ...
Delta 757 at El Dorado Int, Bogota
http://cdn-www.airliners.net/aviation-photos/photos/1/5/6/1482651.jpg