View Full Version : accelerate go distance

28th Oct 2003, 02:55
I know this term isn't used very much anymore, but could someone please give me a definition for accelerate go distance.

28th Oct 2003, 20:19
From this
FAA Test website (http://www.faatest.com/books/FLT/Chapter16/AccelerateStopDistance.htm) :

The "accelerate/go distance" is the total distance required to accelerate the airplane to a specified speed and, assuming failure of an engine at the instant that speed is attained, continue takeoff on the remaining engine to a height of 50 feet.

More: Google (http://www.google.co.uk/search?q=accelerate+go+distance)

31st Oct 2003, 04:14
thanks CB Long!

31st Oct 2003, 18:38
I think the normal term used for 'accelerate-go' is TODA and the definition for TODA is available in any performance book. For performance A aircraft the screen height is 35 ft and not 50 ft.

Captain Stable
31st Oct 2003, 19:44
You sure it's not TODR?

1st Nov 2003, 00:19
TODA = Takeoff distance available, refers to the tarmac available and usually doesnt change much.

TODR = Takeoff Distance Required, refers to the distance required by the aircraft. Changes based on weight, temp, power, slope, wind etc etc etc.

So Captain Stable is right.......


compressor stall
2nd Nov 2003, 20:49
And the TODR does not have to be all tarmac. It can include clearways where the already airborne aircraft can accelerate and climb to the specified height.

3rd Nov 2003, 07:53
The earlier reference to 50ft is quite understandable as "accel-go" is not often seen in relation to heavies but is quite common in light twins in the GAMA format POH performance section.

4th Nov 2003, 22:52
So, is it fair enough to say that accelerate-go distance is the same as take of distance, that is from brake release to 35/50ft +15% for all engines operating and in case of an engine failure no 15%?

Tonic Please
5th Nov 2003, 05:06
That would make sense, yes.

5th Nov 2003, 18:03
I think TODR is the greater of the accelerate-go distance and the all engines take-off to 35ft + 15%. Some manuals give you the information to work the distances out yourself, and others just give you a TOD figure without telling you which factor is limiting.
Most FAA manuals also take into account Accelerate-stop distance without telling which of the three is critical - there may or may not be a balanced field condition (TODR=ASDR). Again they often don't think pilots are bright enough to cope with such complicated details;)

6th Nov 2003, 04:35
Different considerations at play .. TOD AEO, TOD OEI, and ASD.

TODR is the greater of TOD AEO (which includes a pad) and TOD OEI.

If the operation is based on BFL, then ASDR = TODR.

Usually the takeoff charts are reasonably OK to use and, certainly, if the OEM presents a composite chart, it may not be evident which of the various limits is critical.

Beware of landing charts which, in many cases, are unfactored and need to have the relevant factor (typically 1.67) included for operational use.

Tonic Please
6th Nov 2003, 04:53
Can you unabbreviate the abbreivations if you would be so kind? :O

7th Nov 2003, 17:21
Red face ... a thousand pardons .... consider the following unabbreviations .....

TOD = Take-Off Distance
TODA = Take-Off Distance Available
TODR = Take-Off Distance Required
TOD1 = TODR with one quiet one
TOD2 = TODR with two quiet ones
... (etc .. depending on your level of bravado ...)
ASD = Accelerate Stop Distance
ASDA = Accelerate Stop Distance Available
ASDR = Accelerate Stop Distance Required
OEI = One Engine Inoperative
AEO = All Engines Operative
BFL = Balanced Field Length (TODR = ASDR)
OEM = Original Equipment Manufacturer

jargon is a convenient pain in the neck ......

Mad (Flt) Scientist
9th Nov 2003, 15:19
You forgot "OK", John ;)