Cleared for the option... on the ground
 

I was training a multi-commercial student yesterday, and requested "High speed taxi down Runway 27" to show my student engine failure procedures during the take-off roll (performed at or below 50% of VMC).

Tower responded back with, "Cleared for the option 27". We both look at each other, :confused: and not knowing what to say to that, I respond with "Roger, cleared option 27".

I look up Section 8. Spacing and Sequencing, 3-8-1. SEQUENCE/SPACING APPLICATION on ATC Order JO 7110.65T, which states what I already know... "The “Cleared for the Option” procedure will permit an instructor pilot/flight examiner/pilot the option to make a touch-and-go, low approach, missed approach, stop- and-go, or full stop landing. This procedure will only be used at those locations with an operational control tower and will be subject to ATC approval."

What were my options, since I can't take off without a take-off clearance? Possibly a confused controller or a trainee? Anyone get this before?

I don't think the controller understood your request because one of the "options" is NOT high speed taxi operations. BTW, you might consider VmcG, next time.

GF

It may not be controller handbook verbiage but I have heard "cleared for the option" on takeoff in exactly the situation in the original post - engine-out demonstrations on takeoff. I've even heard of it asked for that way.

What they mean is that you are cleared for takeoff, b ut have the option of aborting for training purposes.

They do it this way so you can keep the student guessing...he doesn't know for sure if you're going to cut an engine.

That makes sense, thanks rickair7777.

Re: VmcG - The twin that I fly does not have a listed VmcG speed in the POH or AFM. Vr and Vmc are listed at 80 MPH, Vlof is 85 MPH and Vyse is 105 MPH. The PTSs state that engine-outs on the ground should be done at 50% of VMC. "ENGINE FAILURE DURING TAKEOFF BEFORE VMC (SIMULATED-AMEL and AMES) - NOTE: Engine failure (simulated) shall be accomplished before reaching 50 percent of the VMC”. I understand the definition of VmcA, but the PTS does not specify VmcA or VmcG. Doesn't VmcG only apply to transport category airplanes? If it applies to light twins, anyone have a formula to calculate it?

The physics of Vmcg apply to multi-engine aircraft, the regulatory requirement is for FAR 25 Transport Category aircraft. BUT, you don't know the Vmcg, so don't get too far into the take-off roll and "pull"an engine and find out their is not enough rudder to hold it straight, but the speed is such you are nearing the edge unexpectedly fast.

GF

One would hope than an instructor using this training method already knows from experience how the airplane will react.

Huh?

The physics of an engine failure on the takeoff roll would dictate the the further into the takeoff roll, the easier it would be to control the aircraft in the event of loss of power on one engine.

Did I misunderstand your post?

Well.... I can say that I never used this phraseology in my ATC tower days at a busy general aviation airport in southern California.

But, of course, "Runway 27, cleared for takeoff" accomplishes exactly the same thing. Yes, you can abort a takeoff, but logic must prevail. If there's a Gulfstream 550 on a 2 mile final, probably a bad plan. I would probably call the tower ahead of time and request aborted take-offs, so they had a heads up.

Cleared for the option is not appropriate. If I had a trainee in the tower doing that, we'd talk about it, and they wouldn't have anything to defend themselves with.

Sqwkvfr

Do you understand Vmcg? Yes, as a plane accelerates, the rudder becomes more effective, but there is a speed, below which the rudder cannot overcome the yaw produced by the inoperative or idled engine. Approaching Vmcg, just a few knots one way or the other makes a huge difference in controllability and if the engine isn't very promptly idled will readily send a plane into the dirt. Crosswind also has a significant effect on the actual Vmcg.

In FAR 25 rules, there is a 30 foot deviation from centerline allowed. I can easily see an eager abort training situation on a typical 75 foot wide GA airport near the plane's Vmcg going badly. That's why I bring it up--FAR 23 are not tested for Vmcg speed or characteristics, so you're a test pilot at some point in the take-off.

As Tony said, one of the options in "cleared for the option" is NOT an aborted take-off.

GF

OTOH, I have heard it used as a busy general aviation airport in the Denver area.

Not quite. In theory, "cleared to land" also "accomplishes exactly the same thing "

While, yes, you are always able abort a takeoff or perform a go-around on landing, one method involves ATC being on the same page during a training exercise, always a good thing. Arguably =especially= at a busy airport.

If it's used at my busy GA airport and not your busy GA airport, that's just one of the many local differences we find.

ATC could have used "runway 27 approved as requested".

2-1-18. OPERATIONAL REQUESTS
Respond to a request from another controller, a pilot
or vehicle operator by one of the following verbal
means:
a. Restate the request in complete or abbreviated
terms followed by the word “APPROVED.” The
phraseology “APPROVED AS REQUESTED” may
be substituted in lieu of a lengthy readback.
PHRASEOLOGY-
(Requested operation) APPROVED.
or
APPROVED AS REQUESTED

The big issue here is that the pilot requested an operation that will involve getting on the runway, starting a takeoff roll, and then stopping on the runway. The controller issued a clearance that would normally be issued to a landing aircraft. Should raise questions. Is ATC even talking to you? The controller may have mistakenly used the wrong callsign, and is actually clearing another aircraft for "the option". I personally wouldn't move until we(ATC and pilot/crew) came to a mutual understanding of the requested operation and ATC used some sort of verbiage that assurred me they understand and are approving my possibly lengthy occupancy of the runway. Opportunity to help educate a controller and your student, prevent a pilot deviation or avoid a real close look at the bottom of an aircraft executing the "option". Having said all of that I have heard it used many times just as you described. After 26 years of ATC I have also heard "what the hell is that guy doing", "I didn't clear him to for that", "Call the tower, advise ready to copy the number".

Local differences can't be contradictory with the ATC bible, 7110.65.

Yes, cleared for takeoff or for an airborne plane, cleared to land would work. But, there is already explicit phraseology for the latter, "cleared for the option".

Like many things in life, just because somebody does, does not do something, doesn't mean everything is fine and dandy.

As I stated, the best method is to contact the tower ahead of time to spell out your request !!!!

Tony
former ATC tower, approach, and center

I have heard ATC use the phrase "Cleared for the takeoff option, Runway 27" many times at my local airport for the purpose of training. The original requests sound something like: " XXX Tower, Twin Cessna XXXXX holding short of runway 27, requesting the takeoff option". This was common practice here until about a year or two ago. They will no longer issue a "takeoff option" clearance. However, the training is still accomplished by stating that the "takeoff will be aborted". For instance, "XXX Tower, Twin Cessna XXXXX holding short of runway 27, ready for takeoff. This will be an aborted takeoff." Or something similar to that. I think the main reason is so ATC has clear knowledge of the intentions of the departing aircraft in order to maintain proper spacing.

The takeoff option is commonly used at the airport where my former large part 141 flight school is based, as well. It may not be legal, but it sure is in common practice.

I've used it while at Purdue, and while I was an instructor in Michigan, at PTK and YIP. Basically I use it for a take-off roll, rotation, and low-altitude abort on the long runways. This was of course in SEL's like PA28's, C152's and C172's, no twins.

In fact, as an instructor, I would split the radio's if able(or I would isolate the student and they had no idea), and let the ground-controller know what my intentions were, and if they could pass it on to the tower controller. They would give the "option" clearance to verify what I had requested, and the student was none the wiser.