Check Essential

Here's another coffin corner speed tape pic:

Bellerophon

All the aircraft I've flown commercially could be hand flown quite satisfactorily at altitude, though obviously some handled better than others, and other posters have already replied with many salient points and cautions.

In the early days of the B747, engine thrust was a limiting factor, so, at whatever altitude the engines would take you to, the wing was still performing well below any aerodynamic limit.

Later, in the 80's and 90's, with the advent of ever more powerful engines for the B747, these newer engines were capable of climbing you to altitudes that the wing didn't really want to be at (at that weight), sometimes with a very narrow speed band available between VMAX and VMIN and "Coffin Corner" considerations became an everyday consideration again.

However, some types handled this problem better than others!

To exemplify this point, take a look at how much the available speed margin reduced on this aircraft type, as it climbed the last 5,000 ft to its maximum certified altitude.

The available speed margin is the gap between the black and yellow chequered Barber's Pole (showing the limiting IAS/Mach/Nose Temp) and the highest White Bug (showing VLA) the Lowest Authorised speed, 300kts IAS at those altitudes.







The available speed band reduced by around 50kts in the last part of the climb, but still left a usable speed band of around 130kts (+/- CG problems!) to play with!

The F/Os may have complained when I hand flew her at altitude, but the wings didn't!


Best Regards

Bellerophon

bubi352

aaaa the Concorde

Sink r8

I tried to come up with some smart-a$$ way to end this quote, being so green with envy and all, but I'm at a loss. So far, I have:

"...but of course the cupholders were a little small..."

"...and then again, we had great difficulty getting ride reports at our altitude, and so we had to slow down, you know, below 2.0 just in case..."

"...but we often missed the cozy camaraderie of the NAT's..."

"...but the true pain was always to fly away from our loved ones so fast, and not slowly enough towards our families and our Chief Pilot..."

"...but we never got the real cool two or three-digits callsigns. Unless you count the two zeros in front of the 7..."


Stuff like that.

Dizel8

Bellerophon,

Dear God how I envy you!

DAL 88 Driver

I've been flying the MD-88 for almost 12 years now. I think it handles fine at high altitudes. It's more pitch sensitive at the higher altitudes. Like someone else said, you have to constantly make a lot of small, delicate control inputs... you can't just trim it up and let go for any length of time. The thin wing is definitely a problem on that airplane, and maintaining an appropriate cruise speed is critical.

I found the handling at high altitudes to be about the same with the B-727 and the DC-9. A little pitch sensitive... but not nearly as bad as the Jetstream 32 I flew years ago!

Jetjok

Personally I don't see any reason to hand fly a heavy jet at the upper altitudes of its flight envelope. You are really not learning anything of value, because if you have to hand fly the jet, you'd be doing it at a much lower altitude, and lower airspeed as well. Apparently McDonnell Douglas feels the same way. Below is copied from our MEL and it addresses having both autopilots inop:

MD-11 Minimum Equipment List
ATA - 22 AUTOFLIGHT
Remarks or Exceptions Note(s)
Refer to MEL item 22-10-01-A for alternate relief.
This system may be required for certain procedures. Refer to minimum aircraft equipment requirements for
planned procedures (CFM and/or route manual).
Cruise performance will be affected.
OPERATIONS (O)
1. DO NOT conduct RVSM operations.
2. DO NOT conduct operations above 78° N Latitude.
3. DO NOT operate aircraft above 25,000 ft. MSL.
4. Fuel burn is increased by 2.7%.
5. Select/confirm both AFS OVRD Switches - OFF.
NOTE 1: Disables A/P, ATS, and automatic high/low speed protection.
NOTE 2: With both AFS OVRD OFF switches in the OFF (down) position, Tail Fuel Management will not be performed.
NOTE 3: With both AFS OVRD OFF switches in the OFF (down) position, low speed thrust protection is unavailable.
NOTE 4: With AFS OVRD OFF switch in the OFF (down) position, an amber and gray bar comes into view.


JJ

Check Essential

The forum software thinks if a colon is followed by a capital D that you must be trying to create a cute smiley emoticon and it pastes one for you.

Idiot computer.

If you want to get rid of it then edit your post to include a space between the colon and the D.

Jetjok

Thanks, it's fixed.

sailingfun

The MD 11 was a somewhat unique aircraft. The tail was 30 percent smaller then the DC10. Most transport aircraft don't have restrictions like that on flight without a autopilot. I once flew a 767 for 6 hours without a autopilot. No big deal and flew just great at FL380. We often flew the 727 dispatched without a working autopilot. Again it was no big deal and flew fine. Coffin corner in my mind has always been when you get a 15 knot or less margin between stall and mach buffet. I don't think any current airlines get anywhere near that margin.