RWS 19 – Height Velocity Diagram with Shawn Coyle

Whether you walk away from a landing after an helicopter engine failure or not depends on many things but one good predictor is the Height Velocity(H/V) diagram. The H/V diagram (also known as H/V curve and dead man’s curve) represents combinations of airspeeds and altitudes that have been determined for that helicopter type where it …

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The post RWS 19 – Height Velocity Diagram with Shawn Coyle appeared first on The Rotary Wing Show Podcast.

Shawn Coyle is an experienced helicopter test pilot with a passion for helping other pilots learn more about their profession.

Whether you walk away from a landing after an helicopter engine failure or not depends on many things but one good predictor is the Height Velocity(H/V) diagram.

The H/V diagram (also known as H/V curve and dead man’s curve) represents combinations of airspeeds and altitudes that have been determined for that helicopter type where it will be difficult or impossible to safely land the helicopter.

But how is the diagram or chart arrived at?

What are the conditions it is tested under?

In this episode of the Rotary Wing Show test pilot Shawn Coyle takes us in great detail through the diagram and the machinations that go into building one. Shawn’s experience ranges from civil and military operational flying to certification flight testing and training experimental test pilots.

An author of several well know helicopter books Shawn also on occasion acts as an expert witness and on crash investigations.

After listening to this episode you will have a much greater understanding of how the H/V diagram is derived, what it means for your flying operations and probably a reluctance to let your hover height drift upwards.

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In this week’s episode:

01:20 Weather extremes on social media streams

01:48 Listener voicemail

03:25 Hello to our Croatian listener!

04:00 Height velocity diagram

05:50 Guest Shawn Coyle bio

06:06 Early start to flying in Air Cadets

06:47 Jet training then sent to helicopters

08:16 Freedom of action as a helicopter pilot

09:20 Test pilot school

11:42 Flying with the Brits

15:10 Writing books on helicopters

18:14 Automatic flight control systems

27:05 What is a height velocity diagram

27:50 Conditions used to record results

29:35 Where do you go to perform tests?

30:45 Other names for the curve and misnomers – ‘dead man’s curve’

32:41 Background of the diagram

33:28 Engine failure rates and lack of data

35:10 3 engine failures for Shawn

36:50 Delayed pilot response built into the height velocity diagram

41:03 Low hover point test technique

42:43 Impact of aging aircraft on curve

44:06 Number of data points required to construct the diagram

45:20 Verification process by certification authority

45:50 Paved level surface for touchdown, no zero touchdown requirement

47:10 What happens if you test on grass….

48:45 The scariest point to test and amount of nose down

50:34 Insurance impact of the height velocity diagram and limitation vs performance consideration

52:20 Low altitude, high speed section of the diagram

53:30 Best advice when you have to operate in shaded area

54:45 Applicability for approaches and arrivals

55:55 Ray Prouty dinner story

57:18 Piece of advice that you would pass on

59:20 2015 plans and travel

1:00:30 Little Book of Autorotations by Shawn Coyle

1:01:50 Sponsors trainmorepilots.com

1:02:10 WorldHelicopterDay.com

Links from this week’s episode:

Shawn’s company Eagle Eye Solutions

Shawn speaks at the CHC 2013 Safety Conference about the certification process

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[Tweet ““Measuring with a micrometer, marking with a chalk line and cutting with a chainsaw””]

[Tweet ““Know exactly what the symptoms are and exactly what you are going to do””]

[Tweet ““Never seen a helicopter say beat me, I love it!! (more than Blackhawk)””]

Have a question for Shawn or topics that you would like him to cover? Let us know in the comments.

The post RWS 19 – Height Velocity Diagram with Shawn Coyle appeared first on The Rotary Wing Show Podcast.