Close call between Cessna and Delta 757 over Orlando Airport

[LSLGuy]

@Riemann

They can do this, but I’m wondering why they would. Isn’t a gentler climb more fuel efficient? Or does the better fuel efficiency from reaching high altitude quicker offset any loss of efficiency in the climb itself? I can’t imagine it’s a safety thing - I would think the safety margin from a more rapid gain in altitude is likely offset by a greater risk of engine failure at high power.

Here is a discussion I wrote a few years ago about big jet takeoff performance. It and a few posts in either direction gives a decent primer on the topic. Actually, the whole thread has some stuff that may be of interest to those who missed it 8 (!?) years ago.

A Question for the Pilots Here.

As Johnny was saying in small piston airplanes you always take off with maximum available power. The reasons why get a bit deep & I’ll let the light plane folks explain if they can. I can come back to it later if nobody is game. In airline jets the situation is quite different. We rarely use maximum power to take off. Instead we tailor the power to the minimum necessary (defined below) to hoist the weight we have from the runway we’re using under the atmospheric conditions present. There are …

As applied to this incident …
If they were indeed going just to Atlanta and hence very light on fuel, they may well have been using the minimum legal takeoff power. It’s just that the 757 is built a lot more like a Corvette than it is like a UPS van.

There are some circumstances where full takeoff power is called for procedurally. Which varies by carrier, weather, etc., such that we don’t have the data here to speculate. But if they were in one of those situations, there’d be no particular reason for the controller to have anticipated it, nor any reason for the 757 pilots to mention their intent.

Aside: in fighters, we were required to notify the tower if we intended a serious near-max performance takeoff and climb-out versus simply doing our ordinary 50% faster and 100% stronger maneuver than airliner-typical. Precisely because of the vast gulf between climbing out at 5 degrees net upslope vs 10 degrees upslope versus 80 degrees upslope.

@Riemann

I think @LSLGuy is talking about the radio. The 757 pilot switched to Tower frequency just before takeoff. Tower did not inform 757 about the Cessna, and because the Cessna was not actively talking to the tower at the time the 757 was taking off (that’s the “silent sky” imagery) there was also no opportunity for the 757 pilot to passively pick up on its presence.

'Zactly.