It’s early afternoon on June 9, 2016. A Cirrus SR20, November 4252G, is en route
from Norman, Oklahoma to the busy William P. Hobby airport in Houston, Texas. The Cirrus is carrying 3 occupants – the
46-year-old private pilot, her husband, and her brother-in-law. The trio is traveling to visit a relative
who is receiving cancer treatment at a Houston hospital. The 3 hour flight from Norman has been uneventful,
but now, in the busy Class B airspace in Houston, things are about to change. 4252G at one thousand five hundred feet. Cirrus 4252G Hobby Tower, you’re number
two following a 737 on a 3 mile final, caution wake turbulence, runway four, cleared to land. We’ll be runway, er, number two following
the Boeing, runway four, cleared to land, 4252G. Hobby airport has a high volume of air carrier
traffic today, mostly 737’s on the approach to Runway four. Cirrus 4252G is approaching the airport from
the west, about 7 miles out. Winds are out of the east at 12 knots, with
gusts up to 16 knots. The tower has cleared 4252G to land following
a Boeing 737 on a 3 mile final for runway four. But now, another 737 is approaching quickly
from behind. Cirrus 4252G, proceed direct to the numbers,
you’re going to be inside of a 737 intercepting a 10 mile final. Direct to Hobby, 4252G. And Cirrus 52G, maintain maximum forward speed
if able and uh, proceed direct to the numbers, uh, 737’s on a 9 mile final following you
with an 80 knot overtake. Okay I’ll proceed direct to the numbers
and keep the speed up, 4252G. Southwest 235, Hobby Tower, number two following
a Cirrus on a 2 mile final, runway four, cleared to land. Begin reducing to final approach speed if
able. But the faster 737 is overtaking the Cirrus
too quickly. The controller makes a decision. Cirrus 52G, Tower. 4252G. Yeah, I got traffic behind you, just uh, go
around and fly runway heading now, uh, maintain VFR, I’m gonna put you back in a downwind
for runway three five, uh the winds are 090 at 13, gusts 18, can you accept runway three
five? Following his call for a go-around, the controller
has issued a somewhat lengthy set of instructions to the Cirrus. He has also asked the pilot if she can accept
a new runway assignment, runway three five, the winds at zero nine zero at 13 knots, with
gusts up to 18 knots. This would put the airplane at a 15 knot crosswind
component, as well as a 10 degree tailwind. The conditions are less than ideal. However, the pilot of 4252G doesn’t protest. We’re to go around, and line up for runway
three five. N52G, fly runway heading for runway four for
right now. We’ll fly runway heading for 4, 4252G. Shortly afterward, the controller gives further
instructions. N52G, when able, uh go ahead and make a right
downwind now for runway three five and then we’ll just go ahead and keep that right
turn, runway three five, cleared to land. Okay make a right downwind for runway three
five? N52G, yes and just keep the right turn all
the way around, you’re just going to roll right into the base, runway three five, cleared
to land. I’ve got another 737 on a 5 mile final to
runway four and you’re going to be in front of him. 4252G turning around for runway three five. Okay, 52G yeah let’s just, uh, just enter
the right downwind for runway three five. Right downwind 35, 4252 Golf. N52G I’ll call your right base now. At this point, the 737 on final for runway
four is closer than the controller originally anticipated, so he now advises the Cirrus
that they will be landing behind the 737. N52G, make a right base behind that traffic,
runway three five, cleared to land, you’re going to be following them, they’re going
to be landing the crossing runway prior to your arrival. We’ll make a right base following them,
4252G for 35. Now, concerned about traffic separation, the
controller provides new instructions to the Cirrus. Cirrus 52G, make a turn left heading 30 degrees. Left heading 30 degrees, 4252G. Most likely, this instruction from the tower
meant to turn left by thirty degrees. However, the Cirrus begins an extended left
turn, interpreting the controller’s instruction to turn left to a heading of zero three zero
degrees. N52G, did you want to follow the 737 to runway
four? Yes, that would be great, 4252G. N52G, roger, follow the 737 to runway four,
cleared to land. But the Cirrus is still in a left turn, and
at this point is perpendicular and heading away from runway four. Both pilot and controller are confused. So am I turning a right base now, 4252G? N52G, roger, just, uh, maneuver back for the
straight in, I don’t know which way you’re going now, so just turn back around to runway
three five. Turning to 35, I’m so sorry for the confusion,
4252G. That’s okay, we’ll get it. The runway assignment has changed back to
three five, and the Cirrus begins a right turn to line up on final. But at this point, given the earlier confusion,
4252G has already overshot the final for three five. The controller notices this and questions
the pilot. Cirrus 52G, which direction are you turning
now? Uh, I thought I was turning a right base for
35, 4252G. Okay yeah that’s fine, 52G, uh, just make
it, uh, so you’re in a right turn? Keep it tight, I need you to make it tight. Keeping turn tight, 4252 Golf. N52G, I need you to, uh, okay there you go,
straight in to runway three five cleared to land. Straight in to 35, cleared to land, and I
don’t believe I’m lined up for that, 4252G. It’s not entirely clear why the pilot makes
this statement. The Cirrus is almost 2 miles off the threshold
for runway three five, and presumably has enough room to maneuver back to line up on
the centerline. Given the pilot’s earlier response to ATC
that she thought she was turning a right base for three five, it’s likely that she has
become temporarily disoriented, and does not have a clear picture of where the runway should
be. The tower evidently takes her response as
a rejection of the landing clearance. Okay 52G, roger, turn to the right and climb
and maintain one thousand six hundred, right turn. One thousand six hundred, right turn, 4252G. 52G, yes ma’am, heading about 040. 040, 4252G. Now the controller proposes a new course of
action. Okay, 52G let’s do this – can you do a
right turn back to join the straight in to runway three five, could you do it like that? Yes, right turn, back to 35, 4252G. N52G, okay so you’re just going to make
a right turn all the way around to runway three five and now you’re cleared to land. 35, cleared to land, 4252G. Thank you. For the moment, things seem to be going well. Cirrus 52G, okay you’re looking good, just
continue that right turn for runway three five, do you see runway three five still? Yes, 35, 4252G, have it in sight, continuing
my roll around. Yes ma’am, yeah you’re good so you can
start your descent to runway three five there and uh, cleared to land on 35. Cleared to land, 4252G, thank you very much. There’s noticeable relief in the pilot’s
voice. But now, there’s a new problem. Cirrus 4252G is too high on the approach,
and struggling to lose altitude fast enough. To make things worse, the winds have picked
up, and the tailwind is now at 20 degrees. …winds are 100 at 10 – I’m sorry, winds
are 100 at 15, gusts to 20. Okay thank you, trying to lose altitude, 4252G. No problem, little bit of wind off the right. N52G, uh, if you don’t want to land, if
that’s too high we can put you back on the downwind, don’t force it if you can’t. Okay we’ll see. Thank you, 4252G. Twenty seconds later, it’s apparent that
4252G is still too high on the approach. The Cirrus has already crossed the runway
threshold when the tower speaks up. I think you’re too high, Cirrus, uh, 52G,
you might be too high. Okay, we’ll go around then, 4252G. It’s not clear if the pilot hadn’t yet
made the determination that she was too high, or if she was still trying to salvage the
approach. The Cirrus begins the second go-around. Cirrus 52G, roger, just uh, okay, you’re
just going to make right traffic now for runway three five, we’ll come back around and we
got it this time. Sounds perfect, right traffic for 35, 4252G. The Cirrus flies the right downwind leg for
runway three five. Shortly before turning right base, the controller
cautions the Cirrus pilot that another 737 is on final for runway four. N52G, and there’s a 737 on short final,
runway four, touching down right in front of you so just caution wake turbulence right
there at that intersection. Okay, I got that in sight, thank you, 4252G. Roughly one minute later, 4252G has turned
final for runway three five. Again, the Cirrus overshoots the centerline,
perhaps due to the strong winds from the east, but it’s still correctable. The bigger problem is altitude. 4252G is once again too high on the approach. 52G, you have runway three five in sight? Runway three five in sight, 4252G. N52G, winds 090 at 13, gusts 18, runway three
five again cleared to land. 35, cleared to land, trying to get down again,
4252G. No problem. 4252G is unable to lose enough altitude. The pilot initiates a 3rd go-around. 4252G going around, third time will be a charm! Just before the Cirrus announces the go-around,
a new tower controller has taken over. As 4252G is climbing, the controller proposes
a new plan, and instructs the pilot to make left traffic. He also reassigns the Cirrus to runway four. Okay, uh, Cirrus 52G just go ahead and make
the left turn now to enter the downwind, midfield downwind for runway four, if you can just
keep me a nice low tight pattern, I’m going to have traffic 4 miles behind you so I need
you to just kind of keep it in tight if you could. Okay this time I’ll be runway four, turning
left, 4252G. Yeah and actually I might end up sequencing
you behind that traffic, he’s on 4 miles a minute, um, it is gonna to be a little bit
tight with the one behind it so uh, when you get on that downwind, stay on the downwind,
advise me when you have that 737 in sight. We’ll either do 4, or we might swing you
around to 35… But as the controller is speaking, tragedy
strikes. The Cirrus, in a climbing left turn, suddenly
drops a wing. Uh, ma’am, ma’am, uh… straighten up
straighten up! It’s too late. The Cirrus falls rapidly, spinning toward
the ground below. It makes impact in a parking lot just outside
the airport, killing all three aboard. We can’t say for certain whether proficiency,
which is somewhat subjective, was a factor. The pilot earned her private certificate in
May of 2014, and she had logged over 330 hours of flight time, most of those hours in the
Cirrus SR20. She had flown 28 hours over the past 90 days,
and 7 hours over the past 30 days. What we do know is that the sudden loss of
control was caused by the pilot’s decision to retract the flaps before reaching a safe
airspeed during the climb. At the time of the stall, the airplane was
in a left turn, and the flaps-up stall speed of the Cirrus SR20 is between 70 to 75 knots
indicated airspeed in a 15 degree bank. 4252G was only at 62 knots when the pilot
began to retract the flaps. At this airspeed, a stall was inevitable. In its final report, the NTSB determined the
probable cause to be the pilot’s improper go-around procedure that did not ensure that
the airplane was at a safe airspeed before raising the flaps. This resulted in an exceedance of the critical
angle of attack, which caused an accelerated aerodynamic stall and spin into terrain. In addition, the NTSB listed contributing
factors as the first controller's decision to keep the pilot in the traffic pattern (rather
than transferring her back to approach control to start over again), and the second controller's
issuance of an unnecessarily complex clearance during a critical phase of flight. Also listed as a contributing factor was the
pilot's lack of assertiveness. We can start by looking at the most obvious
accident cause – the retraction of the flaps. In this case, by the time the flaps were fully
retracted, the indicated airspeed was at least 10 knots below the stall speed of 70 to 75
knots. The information captured by the airplane’s
flight data recorder reveals other troubling trends. During the first go-around, the pilot began
to retract the flaps at 76 knots indicated airspeed. During the second go-around, she began the
flap retraction at 69 knots. And during the third, at 62 knots. The recommended go-around procedure in the
Cirrus SR20 is to begin retracting flaps only after reaching 81 to 83 knots indicated airspeed. The flight data recorder also shows that on
the third go-around attempt, the pilot began the procedure with full power, but reduced
power to about 80% at the same time as she began to retract the flaps. This further hindered the aircraft’s ability
to gain sufficient airspeed. In addition to the various flap retractions
at low airspeeds, the onboard data recorder suggests other instances of imprecise control. On the initial approach to the airport, the
pilot selected 50% flaps at 130 knots indicated airspeed, ballooned upward, deployed full
flaps, and did not begin to descend until about 40 seconds after the initial flap deployment. An underlying issue seems to be the pilot’s
confidence to fly the airplane where she needed it while managing rapid, complex communications. It’s not known how often she had flown into
busy, controlled airfields or if she had practiced go-around maneuvers in the preceding months. It was, however, revealed that her flight
review was out of date by one month. A CFI had flown with her over 8 months prior
to the incident and considered the pilot to be capable, but this had been part of an early
series of instrument training flights, and did not count as a flight review. Other factors contributing to the accident
focus more on the role of the controllers. According to the NTSB, the air traffic control
instructions given to the pilot were complex and potentially distracting. It’s likely that these complex instructions
would not have been necessary, had the first controller elected to transfer the Cirrus
out of the traffic pattern, and hand the airplane back to approach control for resequencing. Given the pilot’s difficulty with the landing
attempts, it’s reasonable to assume that resequencing could have eliminated many potential
distractions and led to a safer outcome. There was also the matter of the confusing
instruction to “make a turn left heading thirty degrees.” Given the use of the word “heading”, it’s
understandable that the pilot began to turn to a heading of zero three zero degrees. This contributed to the confusion and the
pilot interpreted the incident as her fault, and it likely began to erode her confidence. The second controller’s complex instructions
during the third go-around attempt didn’t help matters, either. The controller requested that the pilot fly
a low, tight left pattern for runway four, a somewhat ambiguous instruction, and he also
delivered lengthy additional communication that did not conform to standard radio protocol. It’s likely that the radio chatter contributed
to the pilot’s distraction from monitoring critical flight parameters. Regarding the NTSB’s findings on the pilot’s
lack of assertiveness, it seems that the pilot’s actions and attempts to comply with ATC are
understandable – after all, the instructions assisted her ultimate goal of landing at the
airport. However, the pilot’s compliance with ATC’s
instructions greatly increased her workload, and led to an extended period of close-in
maneuvering at a busy Class B airport. During this period of maneuvering, it’s
likely that the pilot could have alleviated the situation by either requesting to be re-sequenced,
telling the controller to stand by, or simply stating “unable.” When analyzing the causes of any accident,
it’s important to understand some of the human factors that come into play. Let’s take a deeper look at the pilot’s
supposed lack of assertiveness. What factors led up to this? We don’t know for certain, but the stress
the pilot was experiencing under the deteriorating situation - however well it was managed, may
have contributed. The controller’s request for the first go-around
placed the pilot in the traffic pattern, and landing the Cirrus was clearly the goal for
both ATC and the pilot. But in the confusion that followed, the Cirrus
was kept in the traffic pattern environment and re-routed more than once. This shows a perhaps unnecessary priority
placed on landing the Cirrus at that moment. After the second go-around, and with the 737's
still arriving, the pilot may have felt mounting pressure to land in a hurry to remove herself
from the busy flow of traffic. Pressure clouds judgment and causes people
to make unnecessary mistakes, as does the accompanying stress that often comes with
pressure. It would be a mistake to attribute the causes
of the accident to any one party involved – rather, culpability can be shared partly
by both the pilot and air traffic control. The controllers seemed to realize the pilot
was having trouble landing, and perhaps that’s why they took on a more easygoing and informal
tone of speaking. But in doing so, they sacrificed brevity,
and thus, created potential distraction. More importantly however, for the controllers,
and the pilot, re-sequencing with approach control should have been more prominent in
their minds. As pilots, it’s a reminder to us that exercising
PIC authority affords us the ability to speak up, be assertive, and hit the reset button. We almost always have the option to maneuver
safely away from the situation and take a breather before re-engaging. Then there’s the issue of task saturation. It can make the seemingly simple acts more
difficult. Unfortunately, recognizing task saturation
is challenging. The best course of action, when things get
tense and pressure builds, is to fall back on a ladder of priorities. First, make sure to attain and maintain flying
airspeed. Second, ensure a clear flight path. With these two priorities under control, the
less important items can be managed as able. This includes the third priority - fly the
airplane to the proper position, whether it’s airspace, pattern position, or altitude. Fourth, communicate. And finally, work avionics and other in-cockpit
technology. Failure to set priorities, and to work up
and down the ladder as conditions allow, can have tragic results. In this case, had the pilot fallen back on
these priorities, it could have made a real difference. The events of June 9, 2016 at Hobby airport
expose how quickly seemingly simple operations can turn challenging, problematic, and then
tragic. The accident also stresses the importance
of being able to assert Pilot in Command authority, ignore distractions, and prioritize flying
the airplane under confusing and busy circumstances.
A couple of key notes about this crash:
The pilot was obviously socially-embarrassed by the ridiculousness of the situation. And thus she even began apologizing at various points--at moments that were not her fault, so she had no need to apologize--as well as trying to make a couple of brief light hearted jokes about the ridiculousness of the situation.
In the end: she let social-embarrassment get in the way of her prime duty: the safety of her passengers onboard, and solving the situation.
As well, the control tower unfortunately and repeatedly gave unusually wordy and overly complicated directions. Almost as though at one point they were expecting her to take out a graph paper and plot velocity trajectories of traffic coming up behind!?
Control tower also shockingly did a switch of staff right in the middle of this growingly dangerous situation, along with several other errors on their part as well.
Most aviation accident investigations involve a comedy of errors.
At this point most air travel is advanced enough with enough redundancies you need a couple things to line up, the so-called Swiss cheese model for someone to actually die.
Yikes.
Damn, on all three go-arounds she retracted the flaps at dangerously low speeds, that shit was inevitable.
Imagine the dude who's at work and he locks up for the day thinking about his commute home only to find a motherfucking airplane has fallen out of the sky and landed directly on his car in an otherwise empty parking lot.