The second jet I ever flew was a Super II. SII with Willams conversions. The time between 70 knots and V1 seemed like 2 seconds. Wow what an aircraft.

RDR2000:

Good catch of the American TWA throwback 737 at the 24 second mark.

Good Catch of the American TWA throwback 737.

https://youtu.be/zS2P3s1RSnE?t=24

What a Steve said. There are very few things in a Citation that would cause me to abort a takeoff between 80kts and V1, which is typically around 100 KTS.

On a normal dry takeoff V1 and Vr are within 5 to 10 KTS. So the call is usually V1 ... Rotate.

V1 establishes the point between accelerate-stop and accelerate-go. Lowering V1 gives you more stopping distance. You see that in wet runway calculations where you get a lower V1.

I see no advantage to calling V1 early in Citations. If you are concerned about stopping runway distance then use a wet runway calculation on a dry runway. You may find you are then weight limited.

This is typical for 550’s.

The view from FL340

I had an employee aboard. Shot from the 360. I look uhhh relaxed. Her? Not so much!

Funny!

Ha!
Hi!
Not so much indeed.

Ha!
Hi!
Not so much indeed.

If single pilot, V1 is V1. The early call is a function of the SIC calling early so V1 registers in the PIC’s brain at V1. My SIC called an abort in the sim and I noticed a delay in my reaction.

What this does is make the takeoff distance longer should an engine fail in those padded 5 knots. Basically, you are trying to fly when the airplane would stop sooner than flying.

So instead of a runway overrun at relatively low speed, you are now looking at not being able to takeoff in the remaining runway at higher speed.


The rules for working this all out are in in FAR 25.109 and AC 25-7C. It is pretty complicated and a mixture of aircraft and human performance.

Suffice it to say the rules build in a 2 second delay from engine failure to pilot action.

Also note that the rules are based on the engine failing at Vef (velocity of engine fail) which is LESS than V1, but it is taking recognition time for the pilot to detect an engine has failed. The recognition time is when the plane accelerates from Vef to V1.

So the sequence is:

Vef - engine fails
Pilot recognizes engine failure
V1 - over/under for fly/abort
2 seconds of delay
Abort
more delays for activating speedbrakes, TRs, etc...

Here's the timing diagram from AC 25-7C:


Then they didn't perform as the procedure intends when it comes to RTO.

Mike C.

Even if you are SIC I am staying aware of the airspeed as we approach the bugged V1.

Anything causing me to abort close to V1 I will be aware of as PF - control issues, loss of directional control, smoke in cabin - otherwise we are flying unless we have a lot of extra runway. Engine fire, we are flying. Blown tire, we are flying. Go through the annunciator panel and think carefully about what you really need to abort for between 80 KTS and V1 in a Citation.

You will get during our pre-takeoff brief to call 80 KTS, what our abort criteria is between 80 and V1, and what we will do in case we fly with an engine problem.

Even if you are SIC I am staying aware of the airspeed as we approach the bugged V1.

Anything causing me to abort close to V1 I will be aware of as PF - control issues, loss of directional control, smoke in cabin - otherwise we are flying unless we have a lot of extra runway. Engine fire, we are flying. Blown tire, we are flying. Go through the annunciator panel and think carefully about what you really need to abort for between 80 KTS and V1 in a Citation.

You will get during our pre-takeoff brief to call 80 KTS, what our abort criteria is between 80 and V1, and what we will do in case we fly with an engine problem.